(2001). "Genetic epidemiology of Creutzfeldt-Jakob disease in Europe." Rev Neurol (Paris) 157(6-7): 633-7.
The prion protein gene was studied in patients with definite or probable Creutzfeldt-Jakob disease (CJD) registered by national CJD units of 6 European countries. The role of genetic factors in CJD was also investigated by comparing the frequencies of a family history of dementia and Parkinson's disease in CJD cases and matched controls. Codon 129 genotype was examined in 337 CJD cases of whom 73.2 p. 100 were homozygous for methionine, 10.9 p. 100 were homozygous for valine and 15.7 p. 100 were heterozygous. The genotype frequencies were not statistically different across countries. Future differences, if any, would constitute a meaningful signal for the surveillance of CJD in Europe. A prion protein gene mutation was found in 14.5 p. 100 of CJD cases; only 40 p. 100 of them had a known family history of CJD. The case-control study showed that positive family histories of dementia and Parkinson's disease were both associated with CJD. Although recall bias is the most likely explanation for this finding, the hypothesis that neurodegenerative diseases might share unknown genetic risk factors can also be considered.

Abe, K. and H. Saito (2001). "Effects of basic fibroblast growth factor on central nervous system functions." Pharmacol Res 43(4): 307-12.
Basic fibroblast growth factor (bFGF), initially identified as mitogens with prominent angiogenic properties, is now recognized as multifunctional growth factors with notable actions on neuronal cells. bFGF promotes the survival and neurite growth of brain neurons in vitro and in vivo, suggesting that it functions as a neurotrophic factor. This effect of bFGF could be beneficial for improving the survival of grafted neurons in transplantation. Furthermore, bFGF acutely modulates synaptic transmission in the hippocampus, suggesting that it has a role like a neurotransmitter or neuromodulator. In this article, we make a brief review of multiple biological activities of bFGF for brain neurons and discuss its potential usefulness for the treatment of neurodegenerative disorders including Alzheimer's disease and Parkinson's disease. Copyright 2001 Academic Press.

Abell, C. W. and S. W. Kwan (2001). "Molecular characterization of monoamine oxidases A and B." Prog Nucleic Acid Res Mol Biol 65: 129-56.
Monoamine oxidase A and B (MAO A and B) are the major neurotransmitter-degrading enzymes in the central nervous system and in peripheral tissues. MAO A and B cDNAs from human, rat, and bovine species have been cloned and their deduced amino acid sequences compared. Comparison of A and B forms of the enzyme shows approximately 70% sequence identity, whereas comparison of the A or B forms across species reveals a higher sequence identity of 87%. Within these sequences, several functional regions have been identified that contain crucial amino acid residues participating in flavin adenine dinucleotide (FAD) or substrate binding. These include a dinucleotide-binding site, a second FAD-binding site, a fingerprint site, the FAD covalent-binding site, an active site, and the membrane-anchoring site. The specific residues that play a role in FAD or substrate binding were identified by comparing sequences in wild-type and variants of MAO with those in soluble flavoproteins of known structures. The genes that encode MAO A and B are closely aligned on the X chromosome (Xp11.23), and have identical exon-intron organization. Immunocytochemical localization studies of MAO A and B in primate brain showed distribution in distinct neurons with diverse physiological functions. A defective MAO A gene has been reported to associate with abnormal aggressive behavior. A deleterious role played by MAO B is the activation of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP), a proneurotoxin that can cause a parkinsonian syndrome in mammals. Deprenyl, an inhibitor of MAO B, has been used for the treatment of early-stage Parkinson's disease and provides protection of neurons from age-related decay.

Akhmedova, S. N., A. K. Yakimovsky, et al. (2001). "Paraoxonase 1 Met--Leu 54 polymorphism is associated with Parkinson's disease." J Neurol Sci 184(2): 179-82.
Two up-to-date known paraoxonase 1 (PON1) polymorphisms (Gln--Arg 191 and Leu--Met 54) affect the hydrolysis of toxic oxons and might intensify effects of pollutants, organophosphates and other environmental chemicals in development of Parkinson's disease (PD). We reported previously that PON1 G1n--Arg 191 polymorphism did not influence on the susceptibility to PD. In the present study we have investigated the PON1 Leu--Met 54 polymorphism in 117 patients with sporadic idiopathic PD. A new approach for Leu--Met 54 polymorphism genotyping has been developed. We have showed the frequency of the Met 54 allele of PON1 to be significantly increased in patients with PD compared with the controls (chi(2)=8.63, df=1, P<0.003). The relative risk of PD in the Met 54 allele carriers has been estimated to be 2.3 fold higher than in homozygotes for the L allele. Moreover it appeared to be even 5.15 higher in the subgroup of patients with early-onset PD. We suggest that the Met 54 allele may be considered to be an independent risk factor for PD. This mutation could probably cause PON1 impaired metabolism of environmental neurotoxins and might be responsible for neurodegeneration.

Albers, D. S. and S. J. Augood (2001). "New insights into progressive supranuclear palsy." Trends Neurosci 24(6): 347-53.
Increased oxidative damage and mitochondrial dysfunction have been suggested to play crucial roles in the pathogenesis of several neurodegenerative diseases, including Parkinson's disease and Alzheimer's disease. In this review, we will focus on progressive supranuclear palsy (PSP), a rare parkinsonian disorder with tau pathology. Particular emphasis is placed on the genetic and biochemical data that has emerged, offering new perspectives into the pathogenesis of this devastating disease, especially the contributory roles of oxidative damage and mitochondrial dysfunction.

Andreassen, O. A., R. J. Ferrante, et al. (2001). "Mice with a partial deficiency of manganese superoxide dismutase show increased vulnerability to the mitochondrial toxins malonate, 3-nitropropionic acid, and MPTP." Exp Neurol 167(1): 189-95.
There is substantial evidence implicating mitochondrial dysfunction and free radical generation as major mechanisms of neuronal death in neurodegenerative diseases. The major free radical scavenging enzyme in mitochondria is manganese superoxide dismutase (SOD2). In the present study we investigated the susceptibility of mice with a partial deficiency of SOD2 to the neurotoxins 1-methyl-4-phenyl-1,2,5,6-tetrahydropyridine (MPTP), 3-nitropropionic acid (3-NP), and malonate, which are commonly used animal models of Parkinson's and Huntington's disease. Heterozygous SOD2 knockout (SOD2(+/-)) mice showed no evidence of neuropathological or behavioral abnormalities at 2-4 months of age. Compared to littermate wild-type mice, mice with partial SOD2 deficiency showed increased vulnerability to dopamine depletion after systemic MPTP treatment and significantly larger striatal lesions produced by both 3-NP and malonate. SOD2(+/-) mice also showed an increased production of "hydroxyl" radicals after malonate injection measured with the salicylate hydroxyl radical trapping method. These results provide further evidence that reactive oxygen species play an important role in the neurotoxicity of MPTP, malonate, and 3-NP. These findings show that a subclinical deficiency in a free radical scavenging enzyme may act in concert with environmental toxins to produce selective neurodegeneration.

Anichtchik, O. V., N. Peitsaro, et al. (2001). "Distribution and modulation of histamine H(3) receptors in basal ganglia and frontal cortex of healthy controls and patients with Parkinson's disease." Neurobiol Dis 8(4): 707-16.
Parkinson's disease (PD) is a brain degenerative disorder with unknown etiology, and specific degeneration of mesencephalic dopaminergic cells is a morphological manifestation of the disease. The central histaminergic system appears to be activated in PD, since the histaminergic innervation is increased in the substantia nigra. The aim of the present study was to investigate the expression and function of histamine H(3) receptors in PD, using receptor mRNA in situ hybridization with oligonucleotide probes, receptor binding assay with a specific radioactive agonist, and GTP-gamma-[(35)S]-binding assay as a tool to study the activation of the receptor G-protein. H(3) receptor binding sites were detected using N-alpha-methylhistamine autoradiography in the basal ganglia and cortex, being most abundant in the substantia nigra and striatum. In PD substantia nigra we detected an increase of the receptor binding density. In situ hybridization study of the receptor mRNA revealed prominent sites of H(3) receptor synthesis in the putamen, cortex, and globus pallidus, whereas very low mRNA expression was seen in the substantia nigra. In the PD pallidum externum, H(3) receptor mRNA expression was elevated as compared with the normal brains. GTP-gamma-[(35)S]-binding assay did not reveal any significant difference between PD and normal brains, although the density values in PD substantia nigra tended to be lower than in the normal brain, and density values in PD striatum were higher. The dopaminergic neurons did not express significant amount of H(3) receptor mRNA, suggesting that the effects of H(3) receptor-mediated modulation of dopamine release are indirect. Our data indicates modulation of the histamine H(3) receptor in PD at the level of the mRNA expression in the striatum and receptor density in the substantia nigra. The receptor activity seems to be unchanged or decreased, as revealed by GTP-gamma-[(35)S]-binding assay. Modulation of the histamine H(3) receptor may influence the activity of other neurotransmitter systems, e.g., the GABAergic one, in the substantia nigra.

Aomi, Y., C. S. Chen, et al. (2001). "Cytoplasmic transfer of platelet mtDNA from elderly patients with Parkinson's disease to mtDNA-less HeLa cells restores complete mitochondrial respiratory function." Biochem Biophys Res Commun 280(1): 265-73.
For determination of whether platelet mtDNA in patients with Parkinson's disease (PD) possesses some lesions to reduce respiratory enzyme activities, platelet mtDNA was transferred into mtDNA-less (rho0) HeLa cells from aged PD patients and age-matched normal subjects, since their activities were controlled by both mitochondrial and nuclear genomes. The resultant mtDNA-repopulated cybrid clones containing the HeLa nuclear genome as a common background were used for comparison of respiratory enzyme activities. Remarkable variations of the enzyme activities were observed in the cybrid clones, irrespective of whether their mtDNA was transferred from normal subjects or PD patients, and some of them showed 20% reduction of average activities. Thus, the mtDNA mutations responsible for inducing 20% reduction should be polymorphic rather than pathogenic. On the other hand, pathogenic control cybrid clones possessing mtDNA mutations from patients with mitochondrial disorders showed significant and specific decline of respiratory enzyme complex I activity beyond the normal range of the variations. These observations warrant reassessment of the conventional concept that complex I activity in platelets of PD patients is defective due to mtDNA mutations. Copyright 2001 Academic Press.

Arvanitakis, Z. and Z. K. Wszolek (2001). "Recent advances in the understanding of tau protein and movement disorders." Curr Opin Neurol 14(4): 491-7.
Tau plays an important role in movement disorders. The accumulation of pathological tau is a major substrate of frontotemporal dementia and parkinsonism linked to chromosome 17, progressive supranuclear palsy, and corticobasal degeneration. Over the past year, several new mutations on the tau gene have been found. These mutations have been classified into three groups: (i) mutations in constitutively spliced exons; (ii) mutations in the alternatively spliced exon 10; and (iii) mutations of the exon 10 5' splice site. Some patients presenting with frontotemporal dementia and parkinsonism linked to chromosome 17 transiently respond to levodopa therapy. The significance of Pick bodies was recognized by a recent study on kindred with the Glu342Val tau mutation. In sporadic cases of progressive supranuclear palsy, the presence of the H1 haplotype was found to be a risk factor. Corticobasal degeneration shares a common genetic background with progressive supranuclear palsy. This opens the question of whether corticobasal degeneration represents a separate disorder or a spectrum of disease with progressive supranuclear palsy. However, distinguishing features are observed, and include oculomotor abnormalities, which may help to differentiate these two disorders on clinical grounds. Despite recent advances in the understanding of the tauopathies, there are still no curative therapies available. It is hoped that studies in transgenic tau animal models will lead to the development of successful treatments.

Bandopadhyay, R., R. de Silva, et al. (2001). "No pathogenic mutations in the synphilin-1 gene in Parkinson's disease." Neurosci Lett 307(2): 125-7.
alpha-Synuclein is mutated in rare autosomal dominant forms of Parkinson's disease and is a major component of Lewy bodies and neurites. Synphilin-1, a novel protein interacts in vivo and co-localises with alpha-synuclein in Lewy bodies. We analysed the synphilin-1 gene in familial Parkinson's disease by single-strand conformation polymorphism (SSCP) and automated sequencing but found no coding mutations. However, we identified two novel intronic polymorphisms; an A/T polymorphism in intron 2, resulting in the introduction of an Alu1 site and a second G/T polymorphism in intron 4. We analysed the intron 2 polymorphism for allelic association as it was conducive to rapid screening but observed no changes in frequency between Parkinson's disease cases and controls.

Barbieri, S., K. Hofele, et al. (2001). "Mouse models of alpha-synucleinopathy and Lewy pathology. Alpha-synuclein expression in transgenic mice." Adv Exp Med Biol 487: 147-67.

Bauer, M., M. Meyer, et al. (2001). "Liposome-mediated gene transfer to fetal human ventral mesencephalic explant cultures." Neurosci Lett 308(3): 169-72.
The feasibility of non-viral gene transfer using liposomes is described for human fetal nigral tissue. Ventral mesencephalic explants from 6 to 12 week old fetuses were grown as free-floating roller tube cultures. For the transfection, a vector coding for beta-galactosidase driven by the Rous Sarcoma Virus promoter was used. The developmental stage of the human tissue, time in vitro and the amount of vector DNA used significantly influenced the transfection efficiency. Optimal transfection results were obtained with tissue from a 10 week old fetus, cultured for 4 days and transfected with mixtures containing 4 microg vector DNA. Histological analysis suggested that a specific population of ventral mesencephalic precursor cells were the target for the gene transfer. This finding might have implications for gene delivery and cell replacement strategies in Parkinson's disease.

Beal, M. F. (2001). "Experimental models of Parkinson's disease." Nat Rev Neurosci 2(5): 325-34.
Research into the pathogenesis of Parkinson's disease has been rapidly advanced by the development of animal models. Initial models were developed by using toxins that specifically targeted dopamine neurons, the most successful of which used 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine, a toxin that causes parkinsonism in man. More recently, the identification of alpha-synuclein mutations as a rare cause of Parkinson's disease has led to the development of alpha-synuclein transgenic mice and Drosophila. Here, I discuss the merits and limitations of these different animal models in our attempts to understand the physiology of Parkinson's disease and to develop new therapies.

Beal, M. F. and P. Hantraye (2001). "Novel therapies in the search for a cure for Huntington's disease." Proc Natl Acad Sci U S A 98(1): 3-4.

Begley, S. (2001). "IV. Genes, cells, drugs. Cures for the future. Fountains of youth." Newsweek 138(11A): 84-6.

Berciano, J. (2001). "[Genetics in Parkinson's disease: toward a new nosological era]." Med Clin (Barc) 116(16): 614-6.

Bezard, E., P. Ravenscroft, et al. (2001). "Upregulation of striatal preproenkephalin gene expression occurs before the appearance of parkinsonian signs in 1-methyl-4-phenyl- 1,2,3,6-tetrahydropyridine monkeys." Neurobiol Dis 8(2): 343-50.
GABA and enkephalin-utilizing efferents from the striatum to the external segment of the pallidal complex (GPe) are thought to be overactive in Parkinson's disease (PD). This overactivity is generally held to play a major role in the genesis of parkinsonian symptoms, which are thought to appear when dopaminergic neuronal death exceeds a critical threshold. Little is known, however, regarding the activity of this pathway during disease progression and more particularly, prior to the emergence of parkinsonian symptoms. In order to test the hypothesis that an upregulation of striatal preproenkephalin-A (PPE-A) mRNA levels occurs before the appearance of parkinsonian motor disabilities, the present study assessed PPE-A mRNA expression and striatal dopamine (DA) content following a chronic 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) administration protocol in monkeys that produces a progressive parkinsonian state. Groups ranged from normal to full parkinsonian through asymptomatic lesioned monkeys. The key finding of this study is that PPE-A expression is already upregulated in asymptomatic-lesioned monkeys showing a marked DA depletion (56%). Importantly, this up-regulation is restricted to motor regions of the basal ganglia circuitry. The increased PPE-A mRNA expression observed in asymptomatic, but DA-depleted animals, supports our initial hypothesis of such an upregulation occurring before the appearance of parkinsonian motor disabilities. Furthermore, when considered with recent electrophysiological and histochemical data, these findings question the functional significance of upregulated enkephalin transmission in the indirect striatopallidal pathway. Copyright 2001 Academic Press.

Blair, E., C. Redwood, et al. (2001). "Mutations in the gamma(2) subunit of AMP-activated protein kinase cause familial hypertrophic cardiomyopathy: evidence for the central role of energy compromise in disease pathogenesis." Hum Mol Genet 10(11): 1215-20.
Familial hypertrophic cardiomyopathy (HCM) has been widely studied as a genetic model of cardiac hypertrophy and sudden cardiac death. HCM has been defined as a disease of the cardiac sarcomere, but mutations in the known contractile protein disease genes are not found in up to one-third of cases. Further, no consistent changes in contractile properties are shared by these mutant proteins, implying that an abnormality of force generation may not be the underlying mechanism of disease. Instead, all of the sarcomeric mutations appear to result in inefficient use of ATP, suggesting that an inability to maintain normal ATP levels may be the central abnormality. To test this hypothesis we have examined candidate genes involved in energy homeostasis in the heart. We now describe mutations in PRKAG2, encoding the gamma(2) subunit of AMP-activated protein kinase (AMPK), in two families with severe HCM and aberrant conduction from atria to ventricles in some affected individuals (pre-excitation or Wolff-Parkinson-White syndrome). The mutations, one missense and one in-frame single codon insertion, occur in highly conserved regions. Because AMPK provides a central sensing mechanism that protects cells from exhaustion of ATP supplies, we propose that these data substantiate energy compromise as a unifying pathogenic mechanism in all forms of HCM. This conclusion should radically redirect thinking about this disorder and also, by establishing energy depletion as a cause of myocardial dysfunction, should be relevant to the acquired forms of heart muscle disease that HCM models.

Bonifati, V. (2001). "Monogenic Parkinsonisms and the genetics of Parkinson's disease." Funct Neurol 16(1): 35-44.

Bonifati, V., G. De Michele, et al. (2001). "The parkin gene and its phenotype. Italian PD Genetics Study Group, French PD Genetics Study Group and the European Consortium on Genetic Susceptibility in Parkinson's Disease." Neurol Sci 22(1): 51-2.
Mutations of the parkin gene on chromosome 6 cause autosomal recessive, early onset parkinsonism. This is the most frequent form of monogenic parkinsonism so far identified. The associated phenotypical spectrum encompasses early onset, levodopa-responsive parkinsonism (average onset in the early 30s in Europe), and it overlaps with dopa-responsive dystonia in cases with the earliest onset, and with clinically typical Parkinson's disease in cases with later onset. Despite clinical features, Lewy bodies are not found at autopsy in brains of patients with parkin mutations. The parkin protein possesses ubiquitin ligase activity, which is abolished by the pathogenic mutations.

Bonini, N. M. (2001). "Drosophila as a genetic approach to human neurodegenerative disease." 7(3): 171-175.
Polyglutamine disease is a class of human neurodegenerative diseases characterized by late-onset, progressive neural degeneration. The molecular mechanism is expansion, within the coding region of the respective genes, of a CAG repeat encoding glutamine. The expanded polyglutamine domain confers dominant toxicity on the disease protein, leading to neuronal dysfunction and degeneration. In order to develop Drosophila as a model system to approach and study such human diseases, a human gene encoding an expanded polyglutamine protein was introduced into the fly. Expression of this protein with a pathogenic polyglutamine domain causes late-onset, progressive degeneration of cells in the fly, as it does in humans with disease and mouse transgenic models. Moreover, the protein shows abnormal protein aggregation in flies, similar to human disease tissue. These studies indicate that molecular mechanisms of polyglutamine-induced neurodegeneration are conserved in Drosophila. Through these studies and additional studies to develop fly models for other human neurodegenerative diseases, including Parkinson's disease, the power of Drosophila genetics can be brought to bear toward the molecular understanding and treatment of human neurodegeneration.

Boulu, R. G., C. Mesenge, et al. (2001). "[Neuronal death: potential role of the nuclear enzyme, poly (ADP-ribose) polymerase]." Bull Acad Natl Med 185(3): 555-63; discussion 564-5.
Poly(ADP-ribose) polymerase (PARP, EC 2.4.2.30) is known as a nuclear enzyme that is activated by DNA strand breaks to participate in DNA repair. It is also called poly(ADP-ribose) synthase (PARS) or poly(ADP-ribose) transferase (PADRT). In physiological conditions, PARP plays an important role in maintaining genomic stability. However, for several pathological situations, which include massive DNA injury (brain ischemia for example), excessive activation of PARP can deplete stores of nicotinamide adenine dinucleotide (NAD+), the PARP substrate, which, with the subsequent ATP depletion, leads to cell death. PARP activation appears to play a major role in neuronal death induced by cerebral ischemia, traumatic brain injury, Parkinson disease and other pathologies. PARP inhibitors (3-aminobenzamide and other compounds) and PARP gene deletion induced dramatic neuroprotection in experimental animals (rats, mice). Accordingly, these data suggest that PARP inhibitors could provide a novel therapeutic approach in a wide range of neurodegenerative disorders including cerebral ischemia and traumatic brain injury.

Brattstrom, L. (2001). "Plasma homocysteine and MTHFR C677T genotype in levodopa-treated patients with PD." Neurology 56(2): 281; discussion 281-2.

Brevig, T., M. Meyer, et al. (2001). "Xenotransplantation for brain repair: reduction of porcine donor tissue immunogenicity by treatment with anti-Gal antibodies and complement." Transplantation 72(2): 190-6.
BACKGROUND: Transplantation of embryonic neural tissue is a potential treatment for Parkinson's disease. Because human donor material is in short supply, porcine xenografts are considered a useful alternative. Current immunosuppressive therapies fail, however, to protect intracerebral neural xenografts from host CD4 T lymphocytes. To reduce the immunogenicity of porcine donor tissue, we attempted to remove microglial cells with antibodies against the alpha-galactosyl epitope (Galalpha1,3Galbeta1,4GlcNAc-R), or anti-Gal, and complement, and studied whether this pretreatment can reduce direct and indirect T-cell responses to the tissue. METHODS: Brain tissue from 27-day-old pig embryos was dissociated and treated with human anti-Gal and rabbit complement. The microglial content was analyzed by flow cytometry. [3H]thymidine incorporation in cocultures of the brain cells and purified human CD4 T cells was used to determine direct T-cell responses. Indirect T-cell responses were studied by grafting pretreated and control-pretreated (no anti-Gal) nigral tissue into the lesioned striatum of immunocompetent rats with 6-hydroxydopamine-induced hemiparkinsonism. Amphetamine-induced circling behavior was used to measure graft function. RESULTS: Anti-Gal and complement reduced the microglial content to 11-24% of control and abolished the ability of the brain cells to induce human CD4 T-cell proliferation. Pretreated nigral tissue reduced hemiparkinsonism by more than 50% in five of eight rats at some point during the 10-week follow-up. Rats receiving control-pretreated nigral tissue did not display this degree of improvement. CONCLUSIONS: Pretreatment with anti-Gal and complement can reduce the immunogenicity of porcine neural tissue, and might, therefore, be a valuable alternative or supplement to immunosuppression in neural xenotransplantation.

Brooksbank, C. (2001). "Protein degradation: Parkin finds a partner and a victim." Nat Rev Mol Cell Biol 2(1): 4-5.

Buervenich, S., F. Xiang, et al. (2001). "Identification of four novel polymorphisms in the calcitonin/alpha-CGRP (CALCA) gene and an investigation of their possible associations with Parkinson disease, schizophrenia, and manic depression." Hum Mutat 17(5): 435-6.
We identified novel polymorphisms in the calcitonin/CGRPalpha (CALCA) gene by direct sequencing of genomic DNA and subsequent genotyping by RFLP (restriction fragment length polymorphism) detection and investigated association with neurological or psychiatric disease. Four novel polymorphic alleles were found: two (g.979G>A and g.4218T>C) represented single nucleotide polymorphisms (SNPs), one consisted of two coupled SNPs in close vicinity to each other (g.1210T>C and g.1214C>G), and one was an intronic 16-bp microdeletion (2919-2934del16). One of the SNPs (g.4218T>C) causes a non-synonymous amino acid change (Leu66Pro) in the third exon, an exon common to both procalcitonin and pro-alpha-CGRP. In a subsequent association study, frequencies of the identified polymorphisms in Parkinson and schizophrenia patients were compared with frequencies in the normal population. No statistically significant association was found in our material. The 16-bp microdeletion polymorphism was present in a family with multiple cases of unipolar or bipolar depressive disorder. Using this polymorphism as marker, cosegregation with the phenotype was observed in the majority of individuals. Copyright 2001 Wiley-Liss, Inc.

Callizot, N., J. L. Guenet, et al. (2001). "The frissonnant mutant mouse, a model of dopamino-sensitive, inherited motor syndrome." Neurobiol Dis 8(3): 447-58.
The frissonnant (fri) mutation is an autosomic recessive mutation which spontaneously appeared in the stock of C3H mice. fri mutant mice have locomotor instability and rapid tremor. Since tremor ceases when mutant mice have sleep or are anaesthetized, and because of their obvious stereotyped motor behavior, these mice could represent an inherited Parkinsonian syndrome. We show here that the fri/fri mouse fulfills two out of the three criteria required to validate an experimental model of human disease, that is isomorphism, homology and predictivity. Indeed, fri/fri mice present an important motor deficit accompanying visible tremor and stereotypies. They display some memory deficits as in human Parkinson's desease. l-Dopa and apomorphine (dopaminergic agonists), ropinirole (selective D2 agonist), and selegiline (an monoamino-oxidase B [MAO-B] inhibitor) improve their clinical status. However, neither anatomopathological evidence of nigrostriatal lesion, nor decrease in tyrosine hydroxylase production could be seen. Copyright 2001 Academic Press.

Carvey, P. M., Z. D. Ling, et al. (2001). "A clonal line of mesencephalic progenitor cells converted to dopamine neurons by hematopoietic cytokines: a source of cells for transplantation in Parkinson's disease." Exp Neurol 171(1): 98-108.
Neural progenitor cells potentially provide a limitless, on-demand source of cells for grafting into patients with Parkinson's disease (PD) if the signals needed to control their conversion into dopamine (DA) neurons could be identified. We have recently shown that cytokines which instruct cell division and differentiation within the hematopoeitic system may provide similar functions in the central nervous system. We have shown that mitotic progenitor cells can be isolated from embryonic rat mesencephalon and that these cells respond to a combination of interleukin-1, interleukin-11, leukemia inhibitory factor, and glial cell line-derived neurotrophic factor yielding a tyrosine hydroxylase-immunoreactive (THir) phenotype in 20-25% of total cells. In the present study, 24 clonal cell lines derived from single cells of mesencephalic proliferation spheres were examined for their response to the cytokine mixture. The clone yielding the highest percentage of THir neurons (98%) was selected for further study. This clone expressed several phenotypic characteristics of DA neurons and expression of Nurr1. The response to cytokines was stable for several passages and after cryopreservation for several months. When grafted into the striatum of DA-depleted rats, these cells attenuated rotational asymmetry to the same extent as freshly harvested embryonic DA neurons. These data demonstrate that mesencephalic progenitor cells can be clonally expanded in culture and differentiated in the presence of hematopoietic cytokines to yield enriched populations of DA neurons. When transplanted, these cells provide significant functional benefit in the rat model of PD.

Casali, C., V. Bonifati, et al. (2001). "Mitochondrial myopathy, parkinsonism, and multiple mtDNA deletions in a Sephardic Jewish family." Neurology 56(6): 802-5.
The authors describe a family of Sephardic Jews with progressive external ophthalmoparesis, skeletal muscle weakness, and parkinsonism. Autosomal recessive inheritance was suggested by many consanguineous marriages, although a dominant disorder could not be excluded. No linkage to known progressive external ophthalmoparesis locus was found. The presence of cytochrome c oxidase-negative ragged-red fibers, biochemically reduced respiratory chain complexes, and multiple mitochondrial DNA deletions in muscle biopsies from four patients suggested a new mitochondrial disorder of intergenomic communication.

Chaudhuri, K. R. (2001). "Autonomic dysfunction in movement disorders." Curr Opin Neurol 14(4): 505-11.
Dysfunction of the autonomic nervous system is an under-recognised but important aspect of the aetiological and clinical manifestation of primary degenerative dysautonomias such as multiple system atrophy (MSA) and Parkinson's disease (PD). Although the clinical presentation of dysautonomia in these two disorders may overlap, yet pathological and in vivo imaging studies suggest considerable differences. Functional imaging studies suggest that selective cardiac sympathetic denervation may occur early in PD but not in other parkinsonian syndromes. The clinical implication of this apparently disease specific peripheral dysautonomia is unknown and would be the subject of much interest in future years. Dysautonomia in degenerative disorders also affect respiration, genitourinary function and sleep. Sleep related disorders such as rapid eye movement behaviour disorder and urinary voiding dysfunction appear to precede the development of PD related symptoms while patients with sporadic ataxia have been shown to progress to develop MSA. Dysautonomia has also been recognised in other movement disorders, examples being the combination of dystonia and complex regional pain syndrome with elevated HLA-DR13 and late onset Huntington's disease presenting with dominant parkinsonism and minimal chorea. These studies have helped progress in various diagnostic and management parameters in relation to autonomic dysfunction and movement disorders.

Chen, J. F., K. Xu, et al. (2001). "Neuroprotection by caffeine and A(2A) adenosine receptor inactivation in a model of Parkinson's disease." J Neurosci 21(10): RC143.
Recent epidemiological studies have established an association between the common consumption of coffee or other caffeinated beverages and a reduced risk of developing Parkinson's disease (PD). To explore the possibility that caffeine helps prevent the dopaminergic deficits characteristic of PD, we investigated the effects of caffeine and the adenosine receptor subtypes through which it may act in the 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) neurotoxin model of PD. Caffeine, at doses comparable to those of typical human exposure, attenuated MPTP-induced loss of striatal dopamine and dopamine transporter binding sites. The effects of caffeine were mimicked by several A(2A) antagonists (7-(2-phenylethyl)-5-amino-2-(2-furyl)-pyrazolo-[4,3-e]-1,2,4-triazolo[1,5 -c]pyrimidine (SCH 58261), 3,7-dimethyl-1-propargylxanthine, and (E)-1,3-diethyl-8 (KW-6002)-(3,4-dimethoxystyryl)-7-methyl-3,7-dihydro-1H-purine-2,6-dione) (KW-6002) and by genetic inactivation of the A(2A) receptor, but not by A(1) receptor blockade with 8-cyclopentyl-1,3-dipropylxanthine, suggesting that caffeine attenuates MPTP toxicity by A(2A) receptor blockade. These data establish a potential neural basis for the inverse association of caffeine with the development of PD, and they enhance the potential of A(2A) antagonists as a novel treatment for this neurodegenerative disease.

Chung, K. K., Y. Zhang, et al. (2001). "Parkin ubiquitinates the alpha-synuclein-interacting protein, synphilin-1: implications for Lewy-body formation in Parkinson disease." Nat Med 7(10): 1144-50.
Parkinson disease is a common neurodegenerative disorder characterized by the loss of dopaminergic neurons and the presence of intracytoplasmic-ubiquitinated inclusions (Lewy bodies). Mutations in alpha-synuclein (A53T, A30P) and parkin cause familial Parkinson disease. Both these proteins are found in Lewy bodies. The absence of Lewy bodies in patients with parkin mutations suggests that parkin might be required for the formation of Lewy bodies. Here we show that parkin interacts with and ubiquitinates the alpha-synuclein-interacting protein, synphilin-1. Co-expression of alpha-synuclein, synphilin-1 and parkin result in the formation of Lewy-body-like ubiquitin-positive cytosolic inclusions. We further show that familial-linked mutations in parkin disrupt the ubiquitination of synphilin-1 and the formation of the ubiquitin-positive inclusions. These results provide a molecular basis for the ubiquitination of Lewy-body-associated proteins and link parkin and alpha-synuclein in a common pathogenic mechanism through their interaction with synphilin-1.

Ciechanover, A. (2001). "Linking ubiquitin, parkin and synphilin-1." Nat Med 7(10): 1108-9.

Clostre, F. (2001). "[Mitochondria: recent pathophysiological discoveries and new therapeutic perspectives]." Ann Pharm Fr 59(1): 3-21.
Until about a decade ago, few researchers in clinical or evolutionary biology paid much attention to mitochondria. But over the years, as technological advances in molecular biology made nuclear functions more accessible to them, interest in mitochondria began to revive. First, geneticists started tracing certain rare inherited disorders to mutations in the mitochondria's circular genome. More recently, other researchers have speculated that mitochondria might contribute to aging, either by releasing tissue-damaging reactive oxygen molecules or by impairing and depriving the cell of the energy it needs to function. One the most important recent developments has been the recognition that mitochondria play a central role in the regulation of programmed cell death, or apoptosis. Now, we know that mitochondria play a decisive role in life-death decisions for the cell and may choose between the apoptotic and necrotic pathways. Mitochondria can trigger cell death in a number of ways: by disrupting electron transport and energy metabolism, by activating the mitochondrial permeability transition, by releasing and/or activating proteins that mediate apoptosis. Any or all of these mechanisms may help to explain how mitochondrial defects contribute to the pathogenesis of neuronal death or dysfunction in ischemia/reperfusion injury as well as in human degenerative diseases including Alzheimer's disease, Parkinson's disease, amyotrophic lateral sclerosis and Huntington's disease. This has opened up new avenues for understanding the pathogenesis of neurodegeneration and may lead to new and more effective therapeutic approaches to these diseases.

Conn, K. J., M. D. Ullman, et al. (2001). "Decreased expression of the NADH:ubiquinone oxidoreductase (complex I) subunit 4 in 1-methyl-4-phenylpyridinium -treated human neuroblastoma SH-SY5Y cells." Neurosci Lett 306(3): 145-8.
Oxidative stress and mitochondrial dysfunction have been implicated in Parkinson's disease (PD) pathology. NADH:ubiquinone oxidoreductase (complex I) (EC 1.6.99.3) enzyme activity is aberrant in both PD and 1-methyl-4-phenylpyridinium (MPP(+)) models of PD. Reverse transcription polymerase chain reaction of RNA isolated from MPP(+)-treated human neuroblastoma SH-SY5Y cells identified changes in steady-state mRNA levels of the mitochondrial transcript for subunit 4 of complex I (ND4). Expression of ND4 decreased to nearly 50% after 72 h of MPP(+) (1 mM) exposure. The expression of other mitochondrial transcripts did not change significantly under the same conditions. Pre-incubation of cells with the free-radical spin-trap, N-tert-butyl-alpha-(2-sulfophenyl)-nitrone prior to MPP(+) exposure, prevented decreases in cell viability and ND4 expression. This suggests that functional defects in complex I enzyme activity in PD and MPP(+) toxicity may result from changes in steady-state mRNA levels and that free radicals may be important in this process.

Connor, B., D. A. Kozlowski, et al. (2001). "Glial cell line-derived neurotrophic factor (GDNF) gene delivery protects dopaminergic terminals from degeneration." Exp Neurol 169(1): 83-95.
Previously, we observed that injection of an adenoviral (Ad) vector expressing glial cell line-derived neurotrophic factor (GDNF) into the striatum, but not the substantia nigra (SN), prior to a partial 6-OHDA lesion protects dopaminergic (DA) neuronal function and prevents the development of behavioral impairment in the aged rat. This suggests that striatal injection of AdGDNF maintains nigrostriatal function either by protecting DA terminals or by stimulating axonal sprouting to the denervated striatum. To distinguish between these possible mechanisms, the present study examines the effect of GDNF gene delivery on molecular markers of DA terminals and neuronal sprouting in the aged (20 month) rat brain. AdGDNF or a control vector coding for beta-galactosidase (AdLacZ) was injected unilaterally into either the striatum or the SN. One week later, rats received a unilateral intrastriatal injection of 6-OHDA on the side of vector injection. Two weeks postlesion, rats injected with AdGDNF into either the striatum or the SN exhibited a reduction in the area of striatal denervation and increased binding of the DA transporter ligand [(125)I]IPCIT in the lesioned striatum compared to control animals. Furthermore, injections of AdGDNF into the striatum, but not the SN, increased levels of tyrosine hydroxylase mRNA in lesioned DA neurons in the SN and prevented the development of amphetamine-induced rotational asymmetry. In contrast, the level of T1 alpha-tubulin mRNA, a marker of neuronal sprouting, was not increased in lesioned DA neurons in the SN following injection of AdGDNF either into the striatum or into the SN. These results suggest that GDNF gene delivery prior to a partial lesion ameliorates damage caused by 6-OHDA in aged rats by inhibiting the degeneration of DA terminals rather than by inducing sprouting of nigrostriatal axons. Copyright 2001 Academic Press.

Corti, O. and A. Brice (2001). "Parkin and Parkinson's: more than homonymy?" Ann Neurol 50(3): 283-5.

Cowan, W. M. and E. R. Kandel (2001). "Prospects for neurology and psychiatry." Jama 285(5): 594-600.
Neurological and psychiatric illnesses are among the most common and most serious health problems in developed societies. The most promising advances in neurological and psychiatric diseases will require advances in neuroscience for their elucidation, prevention, and treatment. Technical advances have improved methods for identifying brain regions involved during various types of cognitive activity, for tracing connections between parts of the brain, for visualizing individual neurons in living brain preparations, for recording the activities of neurons, and for studying the activity of single-ion channels and the receptors for various neurotransmitters. The most significant advances in the past 20 years have come from the application to the nervous system of molecular genetics and molecular cell biology. Discovery of the monogenic disorder responsible for Huntington disease and understanding its pathogenesis can serve as a paradigm for unraveling the much more complex, polygenic disorders responsible for such psychiatric diseases as schizophrenia, manic depressive illness, and borderline personality disorder. Thus, a new degree of cooperation between neurology and psychiatry is likely to result, especially for the treatment of patients with illnesses such as autism, mental retardation, cognitive disorders associated with Alzheimer and Parkinson disease that overlap between the 2 disciplines.

Crocker, S. J., N. Wigle, et al. (2001). "NAIP protects the nigrostriatal dopamine pathway in an intrastriatal 6-OHDA rat model of Parkinson's disease." Eur J Neurosci 14(2): 391-400.
Parkinson's disease (PD) is a progressive neurodegenerative disorder of the basal ganglia, associated with the inappropriate death of dopaminergic neurons of the substantia nigra pars compacta (SNc). Here, we show that adenovirally mediated expression of neuronal apoptosis inhibitor protein (NAIP) ameliorates the loss of nigrostriatal function following intrastriatal 6-OHDA administration by attenuating the death of dopamine neurons and dopaminergic fibres in the striatum. In addition, we also addressed the role of the cysteine protease caspase-3 activity in this adult 6-OHDA model, because a role for caspases has been implicated in the loss of dopamine neurons in PD, and because NAIP is also a reputed inhibitor of caspase-3. Although caspase-3-like proteolysis was induced in the SNc dopamine neurons of juvenile rats lesioned with 6-OHDA and in adult rats following axotomy of the medial forebrain bundle, caspase-3 is not induced in the dopamine neurons of adult 6-OHDA-lesioned animals. Taken together, these results suggest that therapeutic strategies based on NAIP may have potential value for the treatment of PD.

de la Fuente-Fernandez, R. and D. B. Calne (2001). "Familial aggregation of Parkinson's disease." N Engl J Med 344(15): 1168.

Delacourte, A. (2001). "The molecular parameters of tau pathology. Tau as a killer and a witness." Adv Exp Med Biol 487: 5-19.

DeStefano, A. L., L. I. Golbe, et al. (2001). "Genome-wide scan for Parkinson's disease: the GenePD Study." Neurology 57(6): 1124-6.
A genome-wide scan for idiopathic PD in a sample of 113 PD-affected sibling pairs is reported. Suggestive evidence for linkage was found for chromosomes 1 (214 cM, lod = 1.20), 9 (136 cM, lod = 1.30), 10 (88 cM, lod = 1.07), and 16 (114 cM, lod = 0.93). The chromosome 9 region overlaps the genes for dopamine beta-hydroxylase and torsion dystonia. Although no strong evidence for linkage was found for any locus, these results may be of value in comparison with similar studies by others.

Dickson, D., M. Farrer, et al. (2001). "Pathology of PD in monozygotic twins with a 20-year discordance interval." Neurology 56(7): 981-2.

Dodel, R. C., F. Lohmuller, et al. (2001). "A polymorphism in the intronic region of the IL-1alpha gene and the risk for Parkinson's disease." Neurology 56(7): 982-3.

Dracheva, S. and V. Haroutunian (2001). "Locomotor behavior of dopamine D1 receptor transgenic/D2 receptor deficient hybrid mice." Brain Res 905(1-2): 142-51.
Mice that incorporate the dopamine D1 receptor transgene controlled by the D1 receptor promoter exhibit a marked increase of D1 binding in several extra-striatal brain regions and show a paradoxical hypokinetic response to D1 agonist [Exp. Neurol. 157 (1999) 169]. The agonist-induced locomotor behavior of D1 receptor transgenic mice is similar to baseline locomotor activity manifested by D2 receptor deficient mice [J. Neurosci. 18 (1998) 3470]. The similarity between these two behavioral phenotypes raised the possibility that stimulation of the over-expressed D1 receptors in the transgenic mice could cause a suppression of D2 receptor responses that manifest in hypokinesia. Alternatively, the similar phenotypes could result from altered D1/D2 receptor balance in both animal models. Two different approaches were undertaken to test these alternative hypotheses. (1) The effects of pharmacological blockade of D2 receptors on D1 agonist-stimulated hypokinesia of the D1 over-expressing animals were investigated. (2) The behavioral phenotype of hybrid D1 receptor over-expressing/D2 receptor deficient mice generated by crossbreeding the D2 knockout mice and the D1 transgenic animals was studied. The results of these studies suggested that the hypomotor response of the D1 transgenic mice was not a result of an interaction of the over-expressed D1 receptors with the native D2 receptors and that over-expressed D1 receptors likely mediate hypokinesia in the D1 transgenic animals. Considering the significance of the D1 dopamine receptor as a therapeutic target for Parkinson's disease, this D1 receptor over-expressing model provides an important experimental system to probe the basis for altered behavioral responses following stimulation of transgenetically up-regulated receptors.

Dujardin, K., L. Defebvre, et al. (2001). "Memory and executive function in sporadic and familial Parkinson's disease." Brain 124(Pt 2): 389-98.
Some studies have demonstrated that the motor symptomatology in sporadic and familial Parkinson's disease was identical. From a physiopathological point of view, and perhaps in the future from a therapeutic point of view, it seems important to determine whether sporadic and familial Parkinson's disease are also similar with regard to cognitive impairment. The aim of the present study was to assess cognitive functions in patients suffering from sporadic and familial Parkinson's disease. Executive functions and memory were investigated in particular. Two groups of 12 patients with Parkinson's disease (sporadic and familial) and 12 healthy controls performed a set of tasks known to evaluate different aspects of executive function and memory. One-way analysis of variance tested for significant group effects, and when justified, post hoc analysis was performed. Cognitive impairment was different in sporadic and familial forms of Parkinson's disease. Indeed, although executive function was impaired in both groups of patients, deficits in tests of explicit memory recall were only observed in patients with sporadic Parkinson's disease. Although the impairment observed in both groups of patients suggests a disruption of the striatoprefrontal circuits, this disruption seems to be quantitatively more important and more widespread in the sporadic patients than in the familial ones. In both patient groups, the deficits probably result from dopaminergic and nondopaminergic deprivation and a greater participation of nondopaminergic factors in patients with sporadic Parkinson's disease could be suggested. In this group, a xenobiotic could be responsible for an acquired metabolic defect involving more widespread structures of the striatoprefrontal circuits, leading to disruption of nondopaminergic loops. Cholinergic deprivation is considered in particular.

During, M. J., M. G. Kaplitt, et al. (2001). "Subthalamic GAD gene transfer in Parkinson disease patients who are candidates for deep brain stimulation." Hum Gene Ther 12(12): 1589-91.
This gene transfer experiment is the first Parkinson's Disease (PD) protocol to be submitted to the Recombinant DNA Advisory Committee. The principal investigators have uniquely focused their careers on both pre-clinical work on gene transfer in the brain and clinical expertise in management and surgical treatment of patients with PD. They have extensively used rodent models of PD for proof-of-principle experiments on the utility of different vector systems. PD is an excellent target for gene therapy, because it is a complex acquired disease of unknown etiology (apart from some rare familial cases) yet it is characterized by a specific neuroanatomical pathology, the degeneration of dopamine neurons of the substantia nigra (SN) with loss of dopamine input to the striatum. This pathology results in focal changes in the function of several deep brain nuclei, which have been well-characterized in humans and animal models and which account for many of the motor symptoms of PD. Our original approaches, largely to validate in vivo gene transfer in the brain, were designed to facilitate dopamine transmission in the striatum using an AAV vector expressing dopamine-synthetic enzymes. Although these confirmed the safety and potential efficacy of AAV, complex patient responses to dopamine augmenting medication as well as poor results and complications of human transplant studies suggested that this would be a difficult and potentially dangerous clinical strategy using current approaches. Subsequently, we and others investigated the use of growth factors, including GDNF. These showed some encouraging effects on dopamine neuron survival and regeneration in both rodent and primate models; however, uncertain consequences of long-term growth factor expression and question regarding timing of therapy in the disease course must be resolved before any clinical study can be contemplated. We now propose to infuse into the subthalamic nucleus (STN) recombinant AAV vectors expressing the two isoforms of the enzyme glutamic acid decarboxylase (GAD-65 and GAD-67), which synthesizes the major inhibitory neurotransmitter in the brain, GABA. The STN is a very small nucleus (140 cubic mm or 0.02% of the total brain volume, consisting of approximately 300,000 neurons) which is disinhibited in PD, leading to pathological excitation of its targets, the internal segment of the globus pallidus (GPi) and substantia nigra pars reticulata (SNpr). Increased GPi/SNpr outflow is believed responsible for many of the cardinal symptoms of PD, i.e., tremor, rigidity, bradykinesia, and gait disturbance. A large amount of data based on lesioning, electrical stimulation, and local drug infusion studies with GABA-agonists in human PD patients have reinforced this circuit model of PD and the central role of the STN. Moreover, the closest conventional surgical intervention to our proposal, deep brain stimulation (DBS) of the STN, has shown remarkable efficacy in even late stage PD, unlike the early failures associated with recombinant GDNF infusion or cell transplantation approaches in PD. We believe that our gene transfer strategy will not only palliate symptoms by inhibiting STN activity, as with DBS, but we also have evidence that the vector converts excitatory STN projections to inhibitory projections. This additional dampening of outflow GPi/SNpr outflow may provide an additional advantage over DBS. Moreover, of perhaps the greatest interest, our preclinical data suggests that this strategy may also be neuroprotective, so this therapy may slow the degeneration of dopaminergic neurons. We will use both GAD isoforms since both are typically expressed in inhibitory neurons in the brain, and our data suggest that the combination of both isoforms is likely to be most beneficial. Our preclinical data includes three model systems: (1) old, chronically lesioned parkinsonian rats in which intraSTN GAD gene transfer results not only in improvement in both drug-induced asymmetrical behavior (apomorphine symmetrical rotations), but also in spontaneous behaviors. In our second model, GAD gene transfer precedes the generation of a dopamine lesion. Here GAD gene transfer showed remarkable neuroprotection. Finally, we carried out a study where GAD-65 and GAD-67 were used separately in monkeys that were resistant to MPTP lesioning and hence showed minimal symptomatology. Nevertheless GAD gene transfer showed no adverse effects and small improvements in both Parkinson rating scales and activity measures were obtained. In the proposed clinical trial, all patients will have met criteria for and will have given consent for STN DBS elective surgery. Twenty patients will all receive DBS electrodes, but in addition they will be randomized into two groups, to receive either a solution containing rAAV-GAD, or a solution which consists just of the vector vehicle, physiological saline. Patients, care providers, and physicians will be blind as to which solution any one patient receives. All patients, regardless of group, will agree to not have the DBS activated until the completion and unblinding of the study. Patients will be assessed with a core clinical assessment program modeled on the CAPSIT, and in addition will also undergo a preop and several postop PET scans. At the conclusion of the study, if any patient with sufficient symptomatic improvement will be offered DBS removal if they so desire. Any patients with no benefit will simply have their stimulators activated, which would normally be appropriate therapy for them and which requires no additional operations. If any unforeseen symptoms occur from STN production of GABA, this might be controlled by blocking STN GABA release with DBS, or STN lesioning could be performed using the DBS electrode. Again, this treatment would not subject the patient to additional invasive brain surgery. The trial described here reflects an evolution in our thinking about the best strategy to make a positive impact in Parkinson Disease by minimizing risk and maximizing potential benefit. To our knowledge, this proposal represents the first truly blinded, completely controlled gene or cell therapy study in the brain, which still provides the patient with the same surgical procedure which they would normally receive and should not subject the patient to additional surgical procedures regardless of the success or failure of the study. This study first and foremost aims to maximally serve the safety interests of the individual patient while simultaneously serving the public interest in rigorously determining in a scientific fashion if gene therapy can be effective to any degree in treating Parkinson's disease.

Ebadi, M., P. Govitrapong, et al. (2001). "Ubiquinone (coenzyme q10) and mitochondria in oxidative stress of parkinson's disease." Biol Signals Recept 10(3-4): 224-53.
Parkinson's disease is the second most common neurodegenerative disorder after Alzheimer's disease affecting approximately1% of the population older than 50 years. There is a worldwide increase in disease prevalence due to the increasing age of human populations. A definitive neuropathological diagnosis of Parkinson's disease requires loss of dopaminergic neurons in the substantia nigra and related brain stem nuclei, and the presence of Lewy bodies in remaining nerve cells. The contribution of genetic factors to the pathogenesis of Parkinson's disease is increasingly being recognized. A point mutation which is sufficient to cause a rare autosomal dominant form of the disorder has been recently identified in the alpha-synuclein gene on chromosome 4 in the much more common sporadic, or 'idiopathic' form of Parkinson's disease, and a defect of complex I of the mitochondrial respiratory chain was confirmed at the biochemical level. Disease specificity of this defect has been demonstrated for the parkinsonian substantia nigra. These findings and the observation that the neurotoxin 1-methyl-4-phenyl-1,2,3, 6-tetrahydropyridine (MPTP), which causes a Parkinson-like syndrome in humans, acts via inhibition of complex I have triggered research interest in the mitochondrial genetics of Parkinson's disease. Oxidative phosphorylation consists of five protein-lipid enzyme complexes located in the mitochondrial inner membrane that contain flavins (FMN, FAD), quinoid compounds (coenzyme Q10, CoQ10) and transition metal compounds (iron-sulfur clusters, hemes, protein-bound copper). These enzymes are designated complex I (NADH:ubiquinone oxidoreductase, EC 1.6. 5.3), complex II (succinate:ubiquinone oxidoreductase, EC 1.3.5.1), complex III (ubiquinol:ferrocytochrome c oxidoreductase, EC 1.10.2.2), complex IV (ferrocytochrome c:oxygen oxidoreductase or cytochrome c oxidase, EC 1.9.3.1), and complex V (ATP synthase, EC 3.6.1.34). A defect in mitochondrial oxidative phosphorylation, in terms of a reduction in the activity of NADH CoQ reductase (complex I) has been reported in the striatum of patients with Parkinson's disease. The reduction in the activity of complex I is found in the substantia nigra, but not in other areas of the brain, such as globus pallidus or cerebral cortex. Therefore, the specificity of mitochondrial impairment may play a role in the degeneration of nigrostriatal dopaminergic neurons. This view is supported by the fact that MPTP generating 1-methyl-4-phenylpyridine (MPP(+)) destroys dopaminergic neurons in the substantia nigra. Although the serum levels of CoQ10 is normal in patients with Parkinson's disease, CoQ10 is able to attenuate the MPTP-induced loss of striatal dopaminergic neurons.

Ellis, C. E., P. L. Schwartzberg, et al. (2001). "alpha-synuclein is phosphorylated by members of the Src family of protein-tyrosine kinases." J Biol Chem 276(6): 3879-84.
alpha-Synuclein (alpha-Syn) is implicated in the pathogenesis of Parkinson's Disease, genetically through missense mutations linked to early onset disease and pathologically through its presence in Lewy bodies. alpha-Syn is phosphorylated on serine residues; however, tyrosine phosphorylation of alpha-Syn has not been established (, ). A comparison of the protein sequence between Synuclein family members revealed that all four tyrosine residues of alpha-Syn are conserved in all orthologs and beta-Syn paralogs described to date, suggesting that these residues may be of functional importance (). For this reason, experiments were performed to determine whether alpha-Syn could be phosphorylated on tyrosine residue(s) in human cells. Indeed, alpha-Syn is phosphorylated within 2 min of pervanadate treatment in alpha-Syn-transfected cells. Tyrosine phosphorylation occurs primarily on tyrosine 125 and was inhibited by PP2, a selective inhibitor of Src protein-tyrosine kinase (PTK) family members at concentrations consistent with inhibition of Src function (). Finally, we demonstrate that alpha-Syn can be phosphorylated directly both in cotransfection experiments using c-Src and Fyn expression vectors and in in vitro kinase assays with purified kinases. These data suggest that alpha-Syn can be a target for phosphorylation by the Src family of PTKs.

Emborg, M. E., P. Shin, et al. (2001). "Systemic administration of the immunophilin ligand GPI 1046 in MPTP-treated monkeys." Exp Neurol 168(1): 171-82.
Systemic administration of immunophilin ligands provides trophic influences to dopaminergic neurons in rodent models of Parkinson's disease (PD) resulting in the initiation of clinical trials in patients with Parkinson's disease. We believe that prior to clinical trials, novel therapeutic strategies should show safety and efficacy in nonhuman models of PD. The present study assessed whether oral administration of the immunophilin 3-(3-pyridyl)-1-propyl (2S)-1-(3,3-dimethyl-1,2-dioxopentyl)-2-pyrrollidinecarboxylate (GPI 1046) could prevent the structural and functional consequences of n-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) administration in nonhuman primates. Twenty-five rhesus monkeys received daily oral administration of vehicle (n = 5) or one of four doses of GPI 1046 (0.3 mg/kg, n = 5; 1.0 mg/kg, n = 5; 3.0 mg/kg, n = 5; 10.0 mg/kg, n = 5). Two weeks after starting the drug treatment, all monkeys received a unilateral intracarotid injection of MPTP-HCl (3 mg). Daily drug administration continue for 6 weeks postlesion after which time the monkeys were sacrificed. Monkeys were assessed for performance on a hand reach task, general activity, and clinical dysfunction based on a clinical rating scale. All groups of monkeys displayed similar deficits on each behavioral measure as well as similar losses of tyrosine hydroxylase (TH)-immunoreactive (ir) nigral neurons, TH-mRNA, and TH-ir striatal optical density indicating that in general treatment failed to have neuroprotective effects. Copyright 2001 Academic Press.

Farin, F. M., Y. Hitosis, et al. (2001). "Genetic polymorphisms of superoxide dismutase in Parkinson's disease." Mov Disord 16(4): 705-7.
Oxidative stress reactions may contribute to the pathogenesis of Parkinson's disease (PD). The superoxide dismutases potentially play significant roles in PD by detoxifying superoxide radical. We developed genomic DNA and cDNA-based sequencing assays to identify genetic variants in the copper/zinc superoxide dismutase (SOD1) and manganese superoxide dismutase (SOD2) genes. No genetic variants were detected in the gene encoding SOD1 in DNA from 45 idiopathic PD cases and 49 controls from a population-based case-control study. However, we identified a previously described polymorphism of the mitochondrial targeting sequence consisting of a C47T in exon 2 of SOD2, which results in an alanine to valine substitution. We analyzed this SOD2 variant in DNA from 155 cases and 231 controls from the same study, using an allele-specific fluorogenic 5' nuclease assay, and found no differences in the distributions of allelic frequencies. These results indicate that SOD gene variants do not contribute to PD pathogenesis.

Farrer, M., P. Chan, et al. (2001). "Lewy bodies and parkinsonism in families with parkin mutations." Ann Neurol 50(3): 293-300.
Previous work has established that compound mutations and homozygous loss of function of the parkin gene cause early-onset, autosomal recessive parkinsonism. Classically, this disease has been associated with loss of dopaminergic neurons in the substantia nigra pars compacta and locus ceruleus, without Lewy body pathology. We have sequenced the parkin gene of 38 patients with early-onset Parkinson's disease (<41 years). Two probands with mutations were followed up. Clinical evaluation of their families was performed, blinded to both genetic and pathological findings. Chromosome 6q25.2-27 haplotype analysis was carried out independently of the trait; parkin gene expression was examined at both the RNA and protein levels. Haplotype analysis of these families revealed a common chromosome 6, with a novel 40 bp exon 3 deletion that cosegregated with disease. In the proband of the smaller kindred, an exon 7 R275W substitution was identified in addition to the exon 3 deletion; RNA analysis demonstrated that the mutations were on alternate transcripts. However, Lewy body pathology typical of idiopathic Parkinson's disease was found at autopsy in the proband from the smaller kindred. These data suggest that compound heterozygous parkin mutations and loss of parkin protein may lead to early-onset parkinsonism with Lewy body pathology, while a hemizygous mutation may confer increased susceptibility to typical Parkinson's disease.

Farrer, M., A. Destee, et al. (2001). "Genetic analysis of synphilin-1 in familial Parkinson's disease." Neurobiol Dis 8(2): 317-23.
alpha-Synuclein is present in Lewy bodies of patients with both sporadic and familial Parkinson's disease. However, pathogenic mutations Ala30Pro and Ala53Thr in alpha-synuclein are rare causes of disease. Synphilin-1 has been demonstrated to associate with alpha-synuclein and promote the formation of cytosolic inclusions in vitro. Two-point genetic linkage analysis of a dinucleotide repeat within the synphilin-1 gene initially implicated this locus as a cause of Parkinson's disease in three of nine families. However, subsequent haplotype, sequencing, and association analyses in these three families and an independent case-control series suggest that variability within the locus does not confer susceptibility to Parkinson's disease. Copyright 2001 Academic Press.

Ferger, B., S. Rose, et al. (2001). "6-hydroxydopamine increases hydroxyl free radical production and DNA damage in rat striatum." Neuroreport 12(6): 1155-9.
Oxidative damage is considered to be an important factor of 6-hydroxydopamine (6-OHDA) toxicity. To address this issue, microdialysis probes were implanted into the striatum of Wistar rats and perfused with 6-OHDA. Salicylate was included in the perfusion fluid to measure 2,3-dihydroxybenzoic acid (2,3-DHBA) as a marker of hydroxyl radical formation using HPLC with electrochemical detection. Additionally, striatal tissue was analysed for DNA base alterations using gas chromatography-mass spectrometry. 6-OHDA administration resulted in a rapid and substantial 6.6-fold increase in 2,3-DHBA formation and also increased levels of the modified DNA bases 5-hydroxycytosine, hypoxanthine and 2,6-diamino-4-hydroxy-5-formamidopyrimidine. Hydroxyl radical formation and DNA base alterations are early phenomena of 6-OHDA toxicity and provide clues to the processes that may be involved in the initiation of cell death in Parkinson's disease.

Figueroa, K. P., P. Chan, et al. (2001). "Association of moderate polyglutamine tract expansions in the slow calcium-activated potassium channel type 3 with ataxia." Arch Neurol 58(10): 1649-53.
BACKGROUND: The small-conductance calcium-activated potassium channel gene (hSKCa3) contains 2 CAG repeats, 1 of which is highly polymorphic. Although this repeat is not pathologically expanded in patients with schizophrenia, some studies have suggested an allelic association with schizophrenia. CAG expansions in other genes such as the alpha1 subunit of a brain-specific P/Q-type calcium channel gene cause spinocerebellar ataxia type 6, whereas the length of the CAG repeat in the RAI1 gene modifies the age of onset of spinocerebellar ataxia type 2. OBJECTIVES: To evaluate expansions in the hSKCa3 polyglutamine domain as causative for ataxia, and to study the association between the length of the polyglutamine repeat and the presence of ataxia. METHODS: We analyzed this repeat in 122 patients with autosomal dominant cerebellar ataxia, or sporadic ataxia, and compared allele distribution with 750 alleles seen in 2 healthy control groups and 172 alleles in patients with Parkinson disease. RESULTS: The distribution of alleles in ataxia patients and controls was significantly different by Wilcoxon rank test (P <.001). Twenty-two or more polyglutamine tracts were more common in ataxia patients compared with controls by chi2 analysis (P<.001). CONCLUSION: Longer stretches of polyglutamines in a human potassium channel are not causative for ataxia, but they are associated with the presence of ataxia. There is no association with the presence of Parkinson disease.

Finkelstein, R., R. W. Baughman, et al. (2001). "Harvesting the neural gene therapy fruit." Mol Ther 3(1): 3-7.

Forsberg, L., U. de Faire, et al. (2001). "Oxidative stress, human genetic variation, and disease." Arch Biochem Biophys 389(1): 84-93.
Oxidative stress has been implicated in numerous pathophysiological conditions and also aging. The tools for studying oxidative stress are now expanding as a result of the human genome effort and, in particular, expanding knowledge on human genetic variation. A few genetic variants, mostly in the form of single nucleotide polymorphisms of relevance to oxidative stress are already studied by a molecular epidemiologic approach. A review of the current knowledge on variant human genes that are directly implicated in human protection against oxidative stress is presented.

Fosslien, E. (2001). "Mitochondrial medicine--molecular pathology of defective oxidative phosphorylation." Ann Clin Lab Sci 31(1): 25-67.
Different tissues display distinct sensitivities to defective mitochondrial oxidative phosphorylation (OXPHOS). Tissues highly dependent on oxygen such as the cardiac muscle, skeletal and smooth muscle, the central and peripheral nervous system, the kidney, and the insulin-producing pancreatic beta-cell are especially susceptible to defective OXPHOS. There is evidence that defective OXPHOS plays an important role in atherogenesis, in the pathogenesis of Alzheimer's disease, Parkinson's disease, diabetes, and aging. Defective OXPHOS may be caused by abnormal mitochondrial biosynthesis due to inherited or acquired mutations in the nuclear (n) or mitochondrial (mt) deoxyribonucleic acid (DNA). For instance, the presence of a mutation of the mtDNA in the pancreatic beta-cell impairs adenosine triphosphate (ATP) generation and insulin synthesis. The nuclear genome controls mitochondrial biosynthesis, but mtDNA has a much higher mutation rate than nDNA because it lacks histones and is exposed to the radical oxygen species (ROS) generated by the electron transport chain, and the mtDNA repair system is limited. Defective OXPHOS may be caused by insufficient fuel supply, by defective electron transport chain enzymes (Complexes I - IV), lack of the electron carrier coenzyme Q10, lack of oxygen due to ischemia or anemia, or excessive membrane leakage, resulting in insufficient mitochondrial inner membrane potential for ATP synthesis by the F0F1-ATPase. Human tissues can counteract OXPHOS defects by stimulating mitochondrial biosynthesis; however, above a certain threshold the lack of ATP causes cell death. Many agents affect OXPHOS. Several nonsteroidal anti-inflammatory drugs (NSAIDs) inhibit or uncouple OXPHOS and induce the 'topical' phase of gastrointestinal ulcer formation. Uncoupled mitochondria reduce cell viability. The Helicobacter pylori induces uncoupling. The uncoupling that opens the membrane pores can activate apoptosis. Cholic acid in experimental atherogenic diets inhibits Complex IV, cocaine inhibits Complex I, the poliovirus inhibits Complex II, ceramide inhibits Complex III, azide, cyanide, chloroform, and methamphetamine inhibit Complex IV. Ethanol abuse and antiviral nucleoside analogue therapy inhibit mtDNA replication. By contrast, melatonin stimulates Complexes I and IV and Gingko biloba stimulates Complexes I and III. Oral Q10 supplementation is effective in treating cardiomyopathies and in restoring plasma levels reduced by the statin type of cholesterol-lowering drugs.

Foureur, N., V. Descamps, et al. (2001). "Bullous pemphigoid in a leg affected with hemiparesia: a possible relation of neurological diseases with bullous pemphigoid?" Eur J Dermatol 11(3): 230-3.
We report a typical case of bullous pemphigoid (BP) associated with a neurological disorder and study a possible link between neurological disorders and BP. An 84-year-old hemiplegic woman presented with unilateral BP on the hemiparetic side. BP was confirmed by histological and immunofluorescence data. The medical records of the previous 46 consecutive patients with BP were retrospectively analyzed (average age: 79; median age: 85). Thirty of the 46 patients with BP had neurological disorders. These disorders included dementia, epilepsy, multiple sclerosis, cerebral stroke, Parkinson's disease, gonadotropic adenoma, trembling, dyskinesia, lumbar spinal stenosis. In a control group of the 46 consecutive oldest patients (older than 71; average age: 82,5; median age: 80) with another skin disease referred during the previous two-year-period to our one-day-unit only, 13 patients had a neurological disorder. This study demonstrates that there is a high prevalence of neurological disorders in patients with BP (p = 0.0004). A prospective case control study with neurological examination and psychometrical evaluation is warranted to confirm these data. We speculate that neuroautoimmunity associated with the aging process or neurological disorders may be involved in pemphigoid development via an autoimmune response against dystonin which shares homology with bullous pemphigoid antigen 1. Bullous pemphigoid could be considered to be a marker of neurological disorder.

Frechilla, D., A. Cobreros, et al. (2001). "Serotonin 5-HT(1A) receptor expression is selectively enhanced in the striosomal compartment of chronic parkinsonian monkeys." Synapse 39(4): 288-96.
Cynomolgus monkeys (Macaca fascicularis) were chronically treated with the dopaminergic neurotoxin 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) until stable parkinsonism was reached. Two months later, monkeys were sacrificed and monoamine content was measured in different brain regions of the lesioned monkeys and of age-matched controls. 5-HT(1A) serotonin receptor density was measured in coronal sections labeled with [(3)H]8-OH-DPAT. As expected, dopamine was virtually nonexistent in the caudate nucleus and putamen of MPTP-treated monkeys. Serotonin levels were significantly reduced in different brain regions, particularly in the raphe nuclei. 5-HT(1A) receptor density of control animals was high in the hippocampus, notably in the CA1 field and also in the raphe nuclei, and much lower in the striatum, where 5-HT(1A) receptors showed a patchy distribution which corresponded to striosomes with poor calbindin immunostaining. 5-HT(1A) receptor density was reduced in hippocampal fields and in the raphe nuclei of parkinsonian monkeys. Conversely, in the severely lesioned striatal nuclei 5-HT(1A) receptor density was increased at caudal levels of the striatum, particularly in the putamen. The results tend to support the possibility of an increased synthesis of 5-HT(1A) receptors in brain regions with higher neuronal cell death. Upregulation of this 5-HT receptor subtype in the limbic compartment of the striatum may represent a compensatory event for the serotonergic dysfunction and associated mental disorders in neurodegenerative diseases such as Parkinson disease. Copyright 2001 Wiley-Liss, Inc.

Fukuhara, Y., T. Takeshima, et al. (2001). "GAPDH knockdown rescues mesencephalic dopaminergic neurons from MPP+ -induced apoptosis." Neuroreport 12(9): 2049-52.
Glyceraldehyde-3-phosphate dehydrogenase (GAPDH; EC 1.2.1.12) has a number of diverse functions apart from glycolytic function. We explored the possible involvement of GAPDH in 1-methyl-4-phenylpyridinium (MPP+)-induced death of mesencephalic dopaminergic neurons (MDNs) in culture. MPP+ (10 and 20 &mgr;M, 24 h) exposure selectively decreased the survival of tyrosine hydroxylase positive (TH+) MDNs, which manifested apoptotic features including shrinkage of the cell body, chromatin condensation and nuclear fragmentation. Two types of GAPDH antisense oligonucleotides almost completely rescued MDNs from MPP+ toxicity. GAPDH was strongly expressed in apoptotic TH+ neurons, and MPP+ exposure significantly increased the percentage of TH+ neurons in which GAPDH is over-expressed. Confocal microscopic analysis demonstrated the nuclear accumulation of GAPDH in neurons undergoing MPP+-induced apoptosis. These results suggest that MPP+ causes apoptosis of MDNs, concomitant with the over-expression and nuclear accumulation of GAPDH.

Fukui, T., Y. Hayashi, et al. (2001). "Suicide gene therapy for human oral squamous cell carcinoma cell lines with adeno-associated virus vector." Oral Oncol 37(3): 211-5.
The purpose of this study was to test the possibility of gene transfer as a new therapy for oral cancer. Adeno-associated virus (AAV) has already been used in the fields of cystic fibrosis and Parkinson's disease as a potential vector for gene therapy because of its wide host range, high transduction efficiency, and lack of cytopathogenicity. Four human oral squamous cell carcinoma cell lines were transduced with an AAV vector containing the beta-galactosidase gene (AAVlacZ) in vitro. Gene transduction efficiency was from 20 to 50% at a multiplicity of infection (MOI; for the purposes of this study the number of vector genomes per target cell) of 1x10(3), and nearly 100% of each cell line were transduced at an MOI of 1x10(4). Next, four cell lines were transduced with an AAV vector containing the herpes simplex virus thymidine kinase (HSVtk) gene, which sensitizes transduced cells to ganciclovir (GCV). Subsequent administration of GCV resulted in nearly 100% tumor cell killing at an MOI of 1x10(4) and from 70 to 80% tumor cell killing at an MOI of 1x10(3). These results suggest that AAV-mediated gene transfer of HSVtk and administration of GCV has potential as a new therapy for oral squamous cell carcinoma.

Galvin, J. E., V. M. Lee, et al. (2001). "Synucleinopathies: clinical and pathological implications." Arch Neurol 58(2): 186-90.
The synucleinopathies are a diverse group of neurodegenerative disorders that share a common pathologic lesion composed of aggregates of insoluble alpha-synuclein protein in selectively vulnerable populations of neurons and glia. Growing evidence links the formation of abnormal filamentous aggregates to the onset and progression of clinical symptoms and the degeneration of affected brain regions in neurodegenerative disorders. These disorders may share an enigmatic symmetry, i.e., missense mutations in the gene encoding for the disease protein (alpha-synuclein) cause familial variants of Parkinson disease as well as its hallmark brain lesions, but the same brain lesions also form from the corresponding wild-type brain protein in the more common sporadic varieties of Parkinson disease. It is likely that clarification of this enigmatic symmetry in 1 form of synucleinopathy will have a profound impact on understanding the mechanisms underlying all these disorders. Furthermore, these efforts will likely lead to novel diagnostic and therapeutic strategies in regard to the synucleinopathies.

Galvin, J. E., T. M. Schuck, et al. (2001). "Differential expression and distribution of alpha-, beta-, and gamma-synuclein in the developing human substantia nigra." Exp Neurol 168(2): 347-55.
Although the functions of alpha-, beta-, and gamma-synuclein (alphaS, betaS, gammaS, respectively) are unknown, these synaptic proteins are implicated in the pathogenesis of Parkinson's disease (PD) and related disorders. For example, alphaS forms Lewy bodies (LBs) in substantia nigra (SN) neurons of PD. However, since it is not known how these hallmark PD lesions contribute to the degeneration of SN neurons or what the normal function of alphaS is in SN neurons, we studied the developing human SN from 11 weeks gestational age (GA) to 16 years of age using immunohistochemistry and antibodies to alphaS, betaS, gammaS, other synaptic proteins, and tyrosine hydoxylase (TH). SN neurons expressed TH at 11 weeks GA and alphaS, betaS, and gammaS appeared initially at 15, 17, and 18 weeks GA, respectively. These synucleins first appeared in perikarya of SN neurons after synaptophysin, but about the same time as synaptotagmin and synaptobrevin. Redistribution of alphaS from perikarya to processes of SN neurons occurred by 18 weeks GA in parallel with synaptophysin, while betaS and synaptotagmin were redistributed similarly between 20 and 28 weeks GA and this also occurred with gammaS and synaptobrevin between 33 weeks GA and 9 months postnatal. These data suggest that alphaS, betaS, and gammaS may play a functional role in the development and maturation of SN neurons, but it remains to be determined how sequestration of alphaS as LBs in PD contributes to the degeneration of SN neurons.

Garcia de Yebenes, J. (2001). "[Genetics of Parkinson's disease]." Neurologia 16(1): 1-6.

Gasser, T. (2001). "Genetics of Parkinson's disease." J Neurol 248(10): 833-40.
Over the past few years, several genes for monogenically inherited forms of Parkinson's disease (PD) have been mapped and/or cloned. In a small number of families with autosomal dominant inheritance and typical Lewy-body pathology, mutations have been identified in the gene for alpha-synuclein. Aggregation of this protein in Lewy-bodies may be a crucial step in the molecular pathogenesis of familial and sporadic PD. On the other hand, mutations in the parkin gene cause autosomal recessive parkinsonism of early onset. In this form of PD, nigral degeneration is not accompanied by Lewy-body formation. Parkin-mutations appear to be a common cause of PD in patients with very early onset. Parkin has been implicated in the cellular protein degradation pathways, as it has been shown that it functions as a ubiquitin ligase. The potential importance of this pathway is also highlighted by the finding of a mutation in the gene for ubiquitin C-terminal hydrolase L1 in another small family with PD. Other loci have been mapped to chromosome 2p and 4p, respectively, in a small number of families with dominantly inherited PD, but those genes have not yet been identified. These findings prove that there are several genetically distinct forms of PD that can be caused by mutations in single genes. On the other hand, there is at present no direct evidence that any of these genes have a direct role in the aetiology of the common sporadic form of PD. Epidemiological, case control, and twin studies, although supporting a genetic contribution to the development of PD, all suggest a clear familial clustering only in a minority of cases. It is therefore widely believed that a combination of interacting genetic and environmental causes may be responsible in this majority of PD-cases. However, studies of gene-environment interactions have not yet produced any convincing results. Nevertheless, the elucidation of the molecular sequence of events leading to nigral degeneration in clearly inherited cases is likely to shed light also on the molecular pathogenesis of the common sporadic form of this disorder.

Gasser, T. (2001). "Molecular genetics of Parkinson's disease." Adv Neurol 86: 23-32.
Over the last few years, several genes for monogenically inherited forms of Parkinson's disease have been mapped and/or cloned. In a large family with autosomal dominant inheritance and typical Lewy-body pathology, a first gene locus has been mapped to the long arm of chromosome 4, and mutations in this and a few other families linked to this locus have been identified in the gene for alpha-synuclein. Aggregation of this protein in Lewy bodies may be a crucial step in the molecular pathogenesis of familial and sporadic Parkinson's disease. A gene causing autosomal recessive parkinsonism of juvenile onset has been mapped to chromosome 6, and the causative gene has been identified and named parkin. A third locus, again in families with dominant inheritance, typical Lewy-body pathology, and late onset, has been mapped to chromosome 2p13, and two additional genes on chromosome 4p have been linked to other dominantly inherited forms of the disease. At present, there is no direct evidence that any of the genes for familial parkinsonian syndromes has a direct role in the etiology of the common sporadic form of PD. However, the elucidation of the molecular sequence of events leading to nigral degeneration in these inherited cases is likely also to shed light on the molecular pathogenesis of the common sporadic disorder.

Goedert, M. (2001). "Alpha-synuclein and neurodegenerative diseases." Nat Rev Neurosci 2(7): 492-501.

Goedert, M. (2001). "Parkinson's disease and other alpha-synucleinopathies." Clin Chem Lab Med 39(4): 308-12.
Parkinson's disease is the most common movement disorder and the second most common neurodegenerative disease. Neuropathologically, it is characterized by the degeneration of nerve cells that develop filamentous inclusions in the form of Lewy bodies and Lewy neurites. Recent work has shown that rare, familial forms of Parkinson's disease are caused by missense mutations in the alpha-synuclein gene and that the filamentous lesions of Parkinson's disease are made of alpha-synuclein. The same is true of the Lewy body pathology that is associated with other neurodegenerative diseases, such as dementia with Lewy bodies. The filamentous inclusions of multiple system atrophy have also been found to be made of alpha-synuclein, thus providing an unexpected molecular link with Lewy body diseases. Recombinant alpha-synuclein assembles into filaments with similar morphologies to those found in the human diseases and with a cross-beta diffraction pattern characteristic of amyloid. The related proteins beta-synuclein and gamma-synuclein are poor at assembling into filaments. They are not present in the pathological filamentous lesions and have not been found to be linked to genetic disease. The new work has established the alpha-synucleinopathies as a major class of neurodegenerative disease.

Goedert, M. (2001). "The significance of tau and alpha-synuclein inclusions in neurodegenerative diseases." Curr Opin Genet Dev 11(3): 343-51.
Intracellular filamentous inclusions made of either the microtubule-associated protein tau or the protein alpha-synuclein define the majority of cases of neurodegenerative disease. Mutations in the tau gene in familial forms of frontotemporal dementia and in the alpha-synuclein gene in familial cases of Parkinson's disease have provided causal links between the dysfunction of these proteins and neurodegeneration. Over the past year, several novel tau gene mutations have been identified and more has been learned about possible mechanisms by which tau gene mutations lead to frontotemporal dementia. Experimental animal models have provided a link between tau filament formation and nerve cell degeneration. Along similar lines, animal models have been produced that result in the formation of alpha-synuclein filaments and the degeneration of dopaminergic nerve cells. Building on previous work, synthetic alpha-synuclein filaments have been shown to exhibit the characteristics of amyloid.

Goedert, M., M. G. Spillantini, et al. (2001). "From genetics to pathology: tau and alpha-synuclein assemblies in neurodegenerative diseases." Philos Trans R Soc Lond B Biol Sci 356(1406): 213-27.
The most common degenerative diseases of the human brain are characterized by the presence of abnormal filamentous inclusions in affected nerve cells and glial cells. These diseases can be grouped into two classes, based on the identity of the major proteinaceous components of the filamentous assemblies. The filaments are made of either the microtubule-associated protein tau or the protein alpha-synuclein. Importantly, the discovery of mutations in the tau gene in familial forms of frontotemporal dementia and of mutations in the alpha-synuclein gene in familial forms of Parkinson's disease has established that dysfunction of tau protein and alpha-synuclein can cause neurodegeneration.

Goetz, C. G., P. F. Burke, et al. (2001). "Genetic variation analysis in parkinson disease patients with and without hallucinations: case-control study." Arch Neurol 58(2): 209-13.
BACKGROUND: Visual hallucinations in Parkinson disease (PD) occur in approximately one third of patients treated long-term with dopaminergic medications. In Alzheimer disease, hallucinations and psychosis have been linked to increased representations of B2/B2 homozyogotes for the dopamine receptor gene DRD1 and 1/1 or 2/2 homozygotes for DRD3. In addition, a previous study of PD patients with and without hallucinations did not show differences in D2 and D3 polymorphisms, although careful case-control matching was not performed. Another study linked the apolipoprotein E4 (APOE4) allele to hallucinations in PD. OBJECTIVE: To determine whether the frequency of dopamine receptor genetic variants and APOE alleles in patients with PD with and without chronic visual hallucinations resembles the pattern previously documented in patients with Alzheimer disease. METHODS: We conducted a case-control study of 44 patients with PD and chronic hallucinations and 44 patients with PD who had never hallucinated. Cases and controls were matched for current age and medications. DNA was isolated from blood samples and assayed for DRD1, DRD2, DRD3, DRD4, and APOE polymorphisms. Receptor polymorphisms were genotyped by polymerase chain reaction. Genotypes in hallucinators and nonhallucinators were compared using Mantel-Haenszel tests stratified by pair, and allele frequencies were compared using Wilcoxon signed rank tests within pairs. RESULTS: Neither D1 receptor genotypes (P =.37) nor allele frequencies (P =.38) differed, and there was no predominance of B2/B2 homozygotes in the hallucinators. For D3, there was a higher frequency of allele 2 (P =.047), but there was no significant difference between frequencies of homozygotes vs heterozygotes (P =.39) as reported in Alzheimer disease. D4 receptor distribution of long and short alleles did not differ between the 2 patient groups, and there were too few C alleles (3 of 86) to compare D2 allele genotypes or frequencies. For APOE, 12 cases and 12 controls carried E4 alleles (P>.99). CONCLUSIONS: With careful case-control matching, visual hallucinations in PD are not associated with the pattern seen for patients with Alzheimer disease and visual hallucinations. Furthermore, there was no association between hallucinations and APOE. Similar methods using larger sample sizes might be adapted to test whether specific dopaminergic receptor genetic variants are associated with visual hallucinations in PD. Based on our data, the DRD3 allele 2 may merit further study.

Golbe, L. I., A. M. Lazzarini, et al. (2001). "The tau A0 allele in Parkinson's disease." Mov Disord 16(3): 442-7.
Parkinson's disease (PD) is primarily an alpha-synucleinopathy, rather than a tauopathy, but there is evidence for an indirect association of tau with the pathogenetic process in PD. We therefore assessed the frequency in PD of the tau A0 allele, a dinucleotide repeat marker that has been associated with a sporadic tauopathy, progressive supranuclear palsy (PSP). We found the A0 allele to comprise 79.2% of 758 alleles from PD patients and 71.2% of 264 control alleles (P = 0.008). We also performed a meta-analysis of three previous reports, two of which failed to produce statistically significant results. Taken together, they also support a PD/A0 allelic association, even after correction for misdiagnosis of PSP as PD (P< 0.001). The A0/A0 genotype frequency in our patients (62.3%) did not differ significantly from that in controls (53.0%, P = 0.062), but the meta-analysis, even after correction for misdiagnosis, showed a significant result, with P = 0.002. The frequency of A0 allele and the A0/A0 genotype were compatible with Hardy-Weinberg equilibrium. The frequency of the A0 allele and the A0/A0 genotype in our patients with familial PD was not significantly greater than in those with sporadic PD. We conclude that the tau protein may play a small role in the pathogenesis of PD and that biochemical characterization of this role may suggest opportunities for PD prophylaxis. Copyright 2001 Movement Disorder Society.

Gollob, M. H., M. S. Green, et al. (2001). "Identification of a gene responsible for familial Wolff-Parkinson-White syndrome." N Engl J Med 344(24): 1823-31.
BACKGROUND: The Wolff-Parkinson-White syndrome, with a prevalence in Western countries of 1.5 to 3.1 per 1000 persons, causes considerable morbidity and may cause sudden death. We identified two families in which the Wolff-Parkinson-White syndrome segregated as an autosomal dominant disorder. METHODS: We studied 70 members of the two families (57 in Family 1 and 13 in Family 2). The subjects underwent 12-lead electrocardiography and two-dimensional echocardiography. Genotyping mapped the gene responsible to 7q34-q36, a locus previously identified to be responsible for an inherited form of Wolff-Parkinson-White syndrome. Candidate genes were identified, sequenced, and analyzed in normal and affected family members to identify the disease-causing gene. RESULTS: A total of 31 members (23 from Family 1 and 8 from Family 2) had the Wolff-Parkinson-White syndrome. Affected members of both families had ventricular preexcitation with conduction abnormalities and cardiac hypertrophy. The maximal combined two-point lod score was 9.82 at a distance of 5 cM from marker D7S636, which confirmed the linkage of the gene in both families to 7q34-q36. Haplotype analysis indicated that there were no alleles in common in the two families at this locus, suggesting that the two families do not have a common founder. We identified a missense mutation in the gene that encodes the gamma2 regulatory subunit of AMP-activated protein kinase (PRKAG2). The mutation results in the substitution of glutamine for arginine at residue 302 in the protein. CONCLUSIONS: The identification of this genetic defect has important implications for elucidating the pathogenesis of ventricular preexcitation. Further understanding of how this molecular defect leads to supraventricular arrhythmias could influence the development of specific therapies for other forms of supraventricular arrhythmia.

Gomez, C., J. Reiriz, et al. (2001). "Low concentrations of 1-methyl-4-phenylpyridinium ion induce caspase-mediated apoptosis in human SH-SY5Y neuroblastoma cells." J Neurosci Res 63(5): 421-8.
There is growing evidence that apoptotic mechanisms underlie the neurodegeneration leading to Parkinson's disease. 1-Methyl-4-phenylpyridinium ion (MPP(+)), the active metabolite of the parkinsonism-inducing drug MPTP, induced apoptosis in cultures of human SH-SY5Y neuroblastoma cells. Nuclear fragmentation, DNA laddering, and a 20% decrease in viability were seen after a 4-day incubation with 5 microM MPP(+). Cell viability decreased by 40% at 100 microM MPP(+), but the degree of apoptosis was not correlatively increased. The MPP(+)-induced apoptosis was completely prevented by the broad caspase inhibitor zVAD.fmk but not by the caspase-8 inhibitor IETD.fmk. Furthermore, MPP(+) had no effect on the levels of Fas or Fas-L, suggesting lack of activation of the Fas-L/Fas/caspase-8 pathway of apoptosis. There was no evidence of mitochondrial dysfunction at 5 microM MPP(+): No differences were seen in transmembrane potential or in cytochrome c release from controls. At 100 microM MPP(+), the mitochondrial potential decreased, and cytoplasmic cytochrome c and caspase-9 activation increased slightly. At both low and high concentrations of MPP(+), VDVADase and DEVDase activities increased. We conclude that MPP(+) can induce caspase-mediated apoptosis, which is prevented by caspase inhibition, at concentrations lower than those needed to trigger mitochondrial dysfunction and closer to those found in the brains of MPTP-treated animals. Copyright 2001 Wiley-Liss, Inc.

Grunblatt, E., S. Mandel, et al. (2001). "Gene expression analysis in N-methyl-4-phenyl-1,2,3,6-tetrahydropyridine mice model of Parkinson's disease using cDNA microarray: effect of R-apomorphine." J Neurochem 78(1): 1-12.
To establish the possible roles of oxidative stress, inflammatory processes and other unknown mechanisms in neurodegeneration, we investigated brain gene alterations in N-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) mice model of Parkinson's disease using Atlas mouse cDNA expression array membrane. The expression of 51 different genes involved in oxidative stress, inflammation, glutamate and neurotrophic factors pathways as well as in still undefined processes, such as cell cycle regulators and signal transduction molecules, was differentially affected by the treatment. The present study indicates the involvement of an additional cascade of events that might act in parallel to oxidative stress and inflammation to converge eventually into a common pathway leading to neurodegeneration. The attenuation of these gene changes by R-apomorphine, an iron chelator-radical scavenger drug, supports our previous findings in vivo where R-apomorphine was neuroprotective.

Guillin, O., J. Diaz, et al. (2001). "BDNF controls dopamine D3 receptor expression and triggers behavioural sensitization." Nature 411(6833): 86-9.
Brain-derived neurotrophic factor (BDNF), like other neurotrophins, is a polypeptidic factor initially regarded to be responsible for neuron proliferation, differentiation and survival, through its uptake at nerve terminals and retrograde transport to the cell body. A more diverse role for BDNF has emerged progressively from observations showing that it is also transported anterogradely, is released on neuron depolarization, and triggers rapid intracellular signals and action potentials in central neurons. Here we report that BDNF elicits long-term neuronal adaptations by controlling the responsiveness of its target neurons to the important neurotransmitter, dopamine. Using lesions and gene-targeted mice lacking BDNF, we show that BDNF from dopamine neurons is responsible for inducing normal expression of the dopamine D3 receptor in nucleus accumbens both during development and in adulthood. BDNF from corticostriatal neurons also induces behavioural sensitization, by triggering overexpression of the D3 receptor in striatum of hemiparkinsonian rats. Our results suggest that BDNF may be an important determinant of pathophysiological conditions such as drug addiction, schizophrenia or Parkinson's disease, in which D3 receptor expression is abnormal.

Gulcher, J. R., A. Kong, et al. (2001). "The role of linkage studies for common diseases." Curr Opin Genet Dev 11(3): 264-7.
Linkage analysis when applied to common diseases has had limited success in mapping the genes contributing to them. We present a genealogic approach applied to the relatively isolated population of Iceland. We use an affecteds-only, allele-sharing method--which does not specify any particular inheritance model--implemented in the new statistical program, Allegro, which calculates lod scores based on multipoint calculations. We describe how this approach has helped us to map a gene contributing to the common late-onset form of Parkinson's disease to statistical significance.

Guzman, M., C. Sanchez, et al. (2001). "Control of the cell survival/death decision by cannabinoids." J Mol Med 78(11): 613-25.
Cannabinoids, the active components of Cannabis sativa (marijuana), and their derivatives produce a wide spectrum of central and peripheral effects, some of which may have clinical application. The discovery of specific cannabinoid receptors and a family of endogenous ligands of those receptors has attracted much attention to cannabinoids in recent years. One of the most exciting and promising areas of current cannabinoid research is the ability of these compounds to control the cell survival/death decision. Thus cannabinoids may induce proliferation, growth arrest, or apoptosis in a number of cells, including neurons, lymphocytes, and various transformed neural and nonneural cells. The variation in drug effects may depend on experimental factors such as drug concentration, timing of drug delivery, and type of cell examined. Regarding the central nervous system, most of the experimental evidence indicates that cannabinoids may protect neurons from toxic insults such as glutamaergic overstimulation, ischemia and oxidative damage. In contrast, cannabinoids induce apoptosis of glioma cells in culture and regression of malignant gliomas in vivo. Breast and prostate cancer cells are also sensitive to cannabinoid-induced antiproliferation. Regarding the immune system, low doses of cannabinoids may enhance cell proliferation, whereas high doses of cannabinoids usually induce growth arrest or apoptosis. The neuroprotective effect of cannabinoids may have potential clinical relevance for the treatment of neurodegenerative disorders such as multiple sclerosis, Parkinson's disease, and ischemia/stroke, whereas their growth-inhibiting action on transformed cells might be useful for the management of malignant brain tumors. Ongoing investigation is in search for cannabinoid-based therapeutic strategies devoid of nondesired psychotropic effects.

Gwinn-Hardy, K., A. Singleton, et al. (2001). "Spinocerebellar ataxia type 3 phenotypically resembling parkinson disease in a black family." Arch Neurol 58(2): 296-9.
BACKGROUND: Machado-Joseph disease (MJD), also known as spinocerebellar ataxia type 3 (SCA3), can present with parkinsonism. However, classically, atypical features, including pyramidal and cerebellar signs, peripheral neuropathy, and/or anterior horn cell dysfunction, are also seen. Levodopa responsiveness is unusual in this disorder. OBJECTIVE: To determine the cause of apparent parkinsonism suggestive of Parkinson disease (PD) in a large family of African origin. METHODS: We studied a large family in which apparent autosomal dominant parkinsonism suggestive of PD occurs in order to find the causal genetic mutation. Affected and unaffected family members were screened for the presence of a pathogenic expansion at the MJD/SCA3 locus using a polymerase chain reaction polyacrylamide gel electrophoresis-based assay. RESULTS: Three of the 4 individuals who were examined have a phenotype reminiscent of PD. Specifically, they have at least 2 of the cardinal features, are levodopa responsive, and have no atypical features. All affected family members were shown to possess pathogenic expansions in the MJD/SCA3 gene. CONCLUSIONS: Parkinsonism suggestive of PD due to MJD/SCA3 has not been previously reported, to our knowledge. However, atypical, though also levodopa-responsive, parkinsonism has been previously reported to occur in African American families, suggesting that that this phenotype is associated with African ancestry. In this regard, it is perhaps significant that all the individuals with parkinsonism have relatively low numbers of repeats (normal, 16-34; pathologic, 60-84). In families in which linkage analysis is being performed to determine a locus for autosomal dominant parkinsonism suggestive of PD, evaluation for the MJD/SCA3 mutation is indicated.

Harhangi, B. S., B. A. Oostra, et al. (2001). "CYP2D6 polymorphism in Parkinson's disease: the Rotterdam Study." Mov Disord 16(2): 290-3.
The CYP2D6 polymorphism has been studied extensively in association with Parkinson's disease (PD), with no consistent results. Several explanations, such as differences in study design or bias in the selection of the control population, have been offered for these inconsistent results. We designed a case control study nested within a prospective population-based cohort study in which cases and controls were sampled from the same source population. To assess the significance of the CYP2D6 gene in PD, we investigated two mutant alleles, CYP2D6*3 and CYP2D6*4, associated with poor metabolism and the wild type allele in 80 patients with PD and 156 matched controls, frequency matched on age and gender. No differences between cases and controls were found for the poor metabolizer genotype. However, we found that in contrast to earlier reports, the CYP2D6*4 mutant allele frequency was lower in cases as compared to controls, albeit not statistically significant. Our result supports the hypothesis that the CYP2D6 gene is not a major gene responsible for PD. Copyright 2001 Movement Disorder Society.

Herceg, Z. and Z. Q. Wang (2001). "Functions of poly(ADP-ribose) polymerase (PARP) in DNA repair, genomic integrity and cell death." Mutat Res 477(1-2): 97-110.
Poly(ADP-ribose) polymerase (PARP) is responsible for post-translational modification of proteins in the response to numerous endogenous and environmental genotoxic agents. PARP and poly(ADP-ribosyl)ation are proposed to be important for the regulation of many cellular processes such as DNA repair, cell death, chromatin functions and genomic stability. Activation of PARP is one of the early DNA damage responses, among other DNA sensing molecules, such as DNA-PK, ATM and p53. The generation and characterization of PARP deficient mouse models have been instrumental in defining the biological role of the molecule and its involvement in the pathogenesis of various diseases including diabetes, stroke, Parkinson disease, general inflammation as well as tumorigenesis, and have, therefore, provided information for the development of pharmaceutical strategies for the treatment of diseases.

Hertz, L., E. Hansson, et al. (2001). "Signaling and gene expression in the neuron-glia unit during brain function and dysfunction: Holger Hyden in memoriam." Neurochem Int 39(3): 227-52.
Holger Hyden demonstrated almost 40 years ago that learning changes the base composition of nuclear RNA, i.e. induces an alteration in gene expression. An equally revolutionary observation at that time was that a base change occurred in both neurons and glia. From these findings, Holger Hyden concluded that establishment of memory is correlated with protein synthesis, and he demonstrated de novo synthesis of several high-molecular protein species after learning. Moreover, the protein, S-100, which is mainly found in glial cells, was increased during learning, and antibodies towards this protein inhibited memory consolidation. S-100 belongs to a family of Ca(2+)-binding proteins, and Holger Hyden at an early point realized the huge importance of Ca(2+) in brain function. He established that glial cells show more marked and earlier changes in RNA composition in Parkinson's disease than neurons. Holger Hyden also had the vision and courage to suggest that "mental diseases could as well be thought to depend upon a disturbance of processes in glia cells as in the nerve cells", and he showed that antidepressant drugs cause profound changes in glial RNA. The importance of Holger Hyden's findings and visions can only now be fully appreciated. His visionary concepts of the involvement of glia in neurological and mental illness, of learning being associated with changes in gene expression, and of the functional importance of Ca(2+)-binding proteins and Ca(2+) are presently being confirmed and expanded by others. This review briefly summarizes highlights of Holger Hyden's work in these areas, followed by a discussion of recent research, confirming his findings and expanding his visions. This includes strong evidence that glial dysfunction is involved in the development of Parkinson's disease, that drugs effective in mood disorders alter gene expression and exert profound effects on astrocytes, and that neuronal-astrocytic interactions in glutamate signaling, NO synthesis, Ca(2+) signaling, beta-adrenergic activity, second messenger production, protein kinase activities, and transcription factor phosphorylation control the highly programmed events that carry the memory trace through the initial, signal-mediated short-term and intermediate memory stages to protein synthesis-dependent long-term memory.

Hilker, R., C. Klein, et al. (2001). "Positron emission tomographic analysis of the nigrostriatal dopaminergic system in familial parkinsonism associated with mutations in the parkin gene." Ann Neurol 49(3): 367-76.
A kindred from South Tyrol (northern Italy) with familial, adult-onset parkinsonism of pseudo-dominant inheritance and mutations in the parkin gene was recently described. To gain insight into basal ganglia dysfunction in this form of hereditary parkinsonism, positron emission tomography (PET) with 18-fluorodopa (FDOPA) and 11C-raclopride (RAC) was performed in 5 affected family members and 5 asymptomatic relatives with proven compound heterozygous or heterozygous parkin mutations. Results were compared to findings in healthy control subjects and patients with typical sporadic, idiopathic Parkinson's disease. Similar to findings in the sporadic Parkinson's disease group, presynaptic striatal FDOPA storage was decreased in patients with compound heterozygous parkin mutations, with the most prominent reduction in the posterior part of the putamen. Along with the presynaptic lowered FDOPA uptake, we found a uniform reduction of the striatal 11C-raclopride binding index in all affected family members as compared to asymptomatic family members carrying a heterozygous parkin mutation, sporadic Parkinson's disease, and control subjects. Our PET data provide evidence that parkinsonism in this family is associated with presynaptic dopaminergic dysfunction similar to idiopathic Parkinson's disease pathophysiology, along with alterations at the postsynaptic D2 receptor level. In asymptomatic carriers of a single parkin mutation with an apparently normal allele, we found a mild but statistically significant decrease of mean FDOPA uptake compared to control subjects in all striatal regions. These data indicate a preclinical disease process in these subjects.

Holm, K. H., F. Cicchetti, et al. (2001). "Enhanced axonal growth from fetal human bcl-2 transgenic mouse dopamine neurons transplanted to the adult rat striatum." Neuroscience 104(2): 397-405.
Embryonic neurons transplanted to the adult CNS extend axons only for a developmentally defined period. There are certain intercellular factors that control the axonal extension, one of which may be the expression of the bcl-2 protein. In this study, rats with complete striatal dopamine fiber denervation received embryonic day 14 mouse ventral mesencephalon cells overexpressing human bcl-2 or control wild-type ventral mesencephalon cells. All rats were treated with cyclosporine to prevent rejection and the surviving grafts were analyzed for cell survival and outgrowth of dopaminergic fibers. The results demonstrate that bcl-2 overexpression does not enhance neuronal graft survival. However, the bcl-2 overexpressing neurons had a higher number of dopaminergic fibers that grew longer distances.These results show that overexpression of bcl-2 can result in longer distance axonal growth of transplanted fetal dopaminergic neurons and that genetic modification of embryonic donor cells may enhance their ability to reinnervate a neuronal target territory.

Horowitz, J. M., J. Myers, et al. (2001). "Spatial distribution, cellular integration and stage development of Parkin protein in Xenopus brain." Brain Res Dev Brain Res 126(1): 31-41.
Parkin is an ubiquitin-protein ligase molecule abundantly expressed in mammalian brains. Deletional mutations of Parkin protein produce a disease-related parkinsonian phenotype which is inherited with an autosomal recessive mode of transmission. To gain a greater insight into the evolutionary trajectory of the protein among vertebrate species, we describe here the (i) distribution pattern, (ii) sizing of specific fragments and (iii) embryonic development of Parkin in Xenopus laevis utilizing two antibodies to the N- and C-terminal sequence of the human Parkin protein. Parkin immunoreactivity was distributed in a heterogeneous fashion throughout the adult frog brain. The telencephalon, including the olfactory bulb, striatum and nucleus accumbens, harbored high numbers of Parkin-containing cells. High numbers of immunoreactive neurons were also present in discrete regions of the thalamus and hypothalamus. Relatively moderate expression of Parkin protein was noted in the nucleus anterodorsalis tegmenti, nucleus reticularis medius and torus semicircularis. The substantia nigra exhibited a distinctive heterogeneous pattern of Parkin-immunoreactivity, especially within presumptive dopamine neurons. The cerebellum also showed high expression of Parkin-positive material. Characterization of the subcellular distribution of the protein indicated both a cytoplasmic and nuclear integration of Parkin-immunoreactivity. This pattern of subcellular localization was similar to that observed in human brain material, perhaps reflecting distinct structural phosphorylation sites of the Parkin protein. Western blot analysis identified three specific bands with molecular weights varying from 50 to 65 kDa in adult Xenopus brain. However, studies on the temporal expression of Parkin during development showed a complete absence of cellular immunoreactivity which was especially conspicuous during late premetamorphic stages of frog development. These results suggest that the ubiquitination activity of Parkin is limited or non-existent during embryogenesis, but appears to assume a more functional role during adulthood as reflected by the high distribution pattern of the protein within major circuits of the amphibian brain.

Horowitz, J. M., V. A. Vernace, et al. (2001). "Immunodetection of Parkin protein in vertebrate and invertebrate brains: a comparative study using specific antibodies." J Chem Neuroanat 21(1): 75-93.
Parkin is an intracellular protein that plays a significant role in the etiopathogenesis of autosomal recessive juvenile parkinsonism. Using immunoblot methods, we found Parkin isoforms varying from 54 to 58 kDa in rat, mouse, bird, frog and fruit-fly brains. Immunocytochemical studies carried out in rats, mice and birds demonstrated multiple cell types bearing the phenotype for Parkin throughout telencephalic, diencephalic, mesencephalic and metencephalic brain structures. While in some instances Parkin-containing neurons tended to be grouped into clusters, the majority of these labeled nerve cells were widely scattered throughout the neuraxis. The topographical distribution and organizational pattern of Parkin within major functional brain circuits was comparable in both rats and mice. However, the subcellular localization of Parkin was found to vary significantly as a function of antibody reactivity. A consistent cytoplasmic labeling for Parkin was observed in rodent tissue incubated with a polyclonal antibody raised against the human Parkin protein and having an identical amino-acid sequence with that of the rat. In contrast, rodent tissue alternately incubated with a polyclonal antibody raised against a different region of the same human Parkin protein but having 10 mismatched amino-acid sequence changes with those of the rat and mouse, resulted in nuclear labeling for Parkin in rat but not mouse neurons. This difference in epitope recognition, however, was reversed when mouse brain tissue was heated at 80 degrees C, apparently unmasking target epitopes against which the antisera were directed. Collectively, these results show a high degree of conservation in the cellular identity of Parkin in animals as different as drosophilids and mammals and points to the possibility that the biochemical specificities of Parkin, including analogous functional roles, may have been conserved during the course of evolution.

Hurley, M. J., D. C. Mash, et al. (2001). "Dopamine D(1) receptor expression in human basal ganglia and changes in Parkinson's disease." Brain Res Mol Brain Res 87(2): 271-9.
The expression of the human dopamine D(1) receptor was examined by reverse transcription polymerase chain reaction (RT-PCR) and radioligand binding using [(3)H]-SCH23390 in post-mortem brain tissue that was obtained from normal subjects and patients dying with Parkinson's disease who were receiving treatment with dopaminergic drugs. D(1) receptor mRNA and specific [(3)H]-SCH23390 binding sites were found in both striatal (nucleus accumbens, caudate nucleus and putamen) and extrastriatal (globus pallidus and substantia nigra) brain regions. In parkinsonian brain, D(1) receptor mRNA was increased in the nucleus accumbens, while a decrease was detected in the substantia nigra pars compacta. No change in D(1) mRNA levels was found in the other brain areas examined. An increase in the density of specific [(3)H]-SCH23390 binding sites was found in the anterior putamen and a decrease in the external segment of the globus pallidus, no changes were detected elsewhere. This study demonstrates that regulation of D(1) receptor expression in the brain of patients dying with Parkinson's disease that were treated with L-DOPA is confined to small alterations in restricted brain regions.

Ilani, T., D. Ben-Shachar, et al. (2001). "A peripheral marker for schizophrenia: Increased levels of D3 dopamine receptor mRNA in blood lymphocytes." Proc Natl Acad Sci U S A 98(2): 625-8.
Dopamine is a major neurotransmitter in the central nervous system, and its receptors are associated with a number of neuropathological disorders such as Parkinson's disease and schizophrenia. Although the precise pathophysiology of schizophrenia remains unknown, the dopaminergic hypothesis of the illness assumes that the illness results from excessive activity at dopamine synapses in the brain. Because, at present, the diagnosis of schizophrenia relies on descriptive behavioral and symptomatic information, a peripheral measurable marker may enable a simpler, more rapid, and more accurate diagnosis and monitoring. In recent years, human peripheral blood lymphocytes have been found to express several dopamine receptors (D(3), D(4), and D(5)) by using molecular biology techniques and binding assays. It has been suggested that these dopamine receptors found on lymphocytes may reflect receptors found in the brain. Here we demonstrate a correlation between the D(3) dopamine receptor on lymphocytes and schizophrenia and show a significant elevation of at least 2-fold in the mRNA level of the D(3), but not of the D(4), dopamine receptor in schizophrenic patients. This increase is not affected by different antipsychotic drug treatments (typical or atypical). Moreover, nonmedicated patients exhibit the same pattern, indicating that this change is not a result of medical treatment. We propose the D(3) receptor mRNA on blood lymphocytes as a marker for identification and followup of schizophrenia.

Ingelson, M., S. F. Fabre, et al. (2001). "Increased risk for frontotemporal dementia through interaction between tau polymorphisms and apolipoprotein E epsilon4." Neuroreport 12(5): 905-9.
The tau gene has an important role in frontotemporal dementia (FTD) as pathogenic mutations have been found in hereditary forms of the disease. Furthermore, a certain extended tau haplotype has been shown to increase the risk for progressive supranuclear palsy, corticobasal degeneration, Parkinson's disease and, in interaction with the apolipoprotein E (apoE) epsilon4 allele, Alzheimer's disease. By microsatellite analysis we investigated an intronic tau polymorphism, in linkage disequilibrium with the extended tau haplotype, in FTD patients (n = 36) and healthy controls (n = 39). No association between any of the tau alleles/genotypes and FTD was seen, but certain tau alleles and apoE epsilon4 interactively increased the risk of FTD (p = 0.006). We thus propose that this extended tau haplotype in combination with apoE epsilon4 is a genetic risk factor for FTD.

Iravani, M. M., S. Costa, et al. (2001). "GDNF reverses priming for dyskinesia in MPTP-treated, L-DOPA-primed common marmosets." Eur J Neurosci 13(3): 597-608.
Parkinson's disease (PD) is associated with a progressive loss of dopamine neurons in the substantia nigra and degeneration of dopaminergic terminals in the striatum. Although L-DOPA treatment provides the most effective symptomatic relief for PD it does not prevent the progression of the disease, and its long-term use is associated with the onset of dyskinesia. In rodent and primate studies, glial cell line-derived neurotrophic factor (GDNF) may prevent 6-OHDA- or MPTP-induced nigral degeneration and so may be beneficial in the treatment of PD. In this study, we investigate the effects of GDNF on the expression of dyskinesia in L-DOPA-primed MPTP-treated common marmosets, exhibiting dyskinesia. GDNF or saline was administered by two intraventricular injections, 4 weeks apart, to MPTP-treated, L-DOPA-treated common marmosets primed to exhibit dyskinesia. Prior to GDNF or saline administration, all animals displayed marked dyskinesia when treated with L-DOPA. GDNF administration produced a significant improvement in motor disability and, following the second injection of GDNF, a significant improvement in the locomotor activity was observed. Following the administration of L-DOPA there was a greater reversal of disability and a reduction in the intensity of L-DOPA-induced dyskinesia in GDNF-treated animals compared to saline-treated controls. However, there was no significant difference in L-DOPA's ability to increase locomotor activity between GDNF-treated and saline-treated animals. GDNF treatment caused a significant increase in the number of tyrosine hydroxylase-positive neurons in the substantia nigra, but no change in [(3)H]mazindol binding to dopamine terminals was found in the striatum of GDNF-treated animals compared to saline-treated controls. In GDNF-treated animals a small but significant reduction in enkephalin mRNA was observed in the caudate nucleus but not in the putamen or the nucleus accumbens. Substance P mRNA expression was equally reduced in the caudate nucleus and the putamen of the GDNF-treated animals but not in the nucleus accumbens. Intraventricular administration of GDNF improved MPTP-induced disability and reverse