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(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.
Behari, M., A. K. Srivastava, et al. (2001). "Risk factors of Parkinson's
disease in Indian patients." J Neurol Sci 190(1-2): 49-55.
Epidemiological data on risk factors of Parkinson's disease (PD) are not
available from India. In a case control study, we investigated environmental and
genetic risk factors in the etiology of idiopathic Parkinson's disease. Three
hundred seventy-seven patients of Parkinson disease (301 men, 76 women,
mean+/-SD age 56.78+/-11.08 years) and equal number of age matched (+/-3 years)
neurological controls (271 men, 106 women, mean+/-SD age 56.62+/-11.17 years)
were included in the study. Conditional logistic regression model was used to
determine the risk factors of PD. We found that male gender, family history of
Parkinson's disease, past history of depression of up to 10-year duration and
well water drinking of more than 10-year duration were significantly associated
with occurrence of Parkinson's disease, whereas tobacco smoking of up to 20-year
duration and exposure to pets had protective effect. However, tobacco smoking of
more than 20-year duration, well water drinking of up to 10-year duration,
vegetarian dietary habit, occupation involving physical exertion, rural living,
farming, exposure to insecticides, herbicides, rodenticides, alcohol intake and
family history of neurodegenerative diseases had no significant correlation with
occurrence of PD in the patient population studied. Results of our study support
the hypothesis of multifactorial etiology of PD with environmental factors
acting on a genetically susceptible host.
Berciano, J. (2001). "[Genetics in Parkinson's disease: toward a new nosological
era]." Med Clin (Barc) 116(16): 614-6.
Bertoni, J. M., J. L. Prendes, et al. (2001). "Long-term Medical Treatment for
Parkinson's Disease." Curr Treat Options Neurol 3(6): 495-506.
The authors of this paper view Parkinson's disease (PD) as a clinically defined
progressive syndrome of resting limb tremor, bradykinesia, muscle rigidity, and
a shuffling unsteady gait that responds well to dopaminergic medications.
Parkinson's disease is a not a single entity, but rather a syndrome with diverse
causes, with both genetic and environmental risk factors. The clinician's
concern is to rule out other entities, especially those having another specific
treatment, and to give PD patients the best short- and long-term benefit, with
the least possible unwanted side effects.
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., 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.
Bonifati, V. (2001). "Monogenic Parkinsonisms and the genetics of Parkinson's
disease." Funct Neurol 16(1): 35-44.
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.
Bostantjopoulou, S., Z. Katsarou, et al. (2001). "Clinical features of
parkinsonian patients with the alpha-synuclein (G209A) mutation." Mov Disord
16(6): 1007-1013.
The motor and neuropsychological abnormalities in eight Greek patients with
Parkinson's disease (PD) carrying the alpha-synuclein gene mutation (G209A) were
studied. These patients (five men, three women) belonged to six different
families. Their symptoms started between 32-50 years of age (mean +/- SD, 39.7
+/- 7.6 years) and they had a mean disease duration of 5.4 +/- 2.1 years (range,
2-9 years) at the time of examination. Rigidity and bradykinesia predominated
both at disease onset as well as in the later stages and rest tremor was
relatively uncommon. Neuropsychological assessment showed that one patient was
mildly demented while another had impairment in memory, visuoconstructive
abilities, and executive function. Depression was present in only one patient.
Our findings indicate that genetic forms of parkinsonism share common motor and
cognitive characteristics with sporadic PD but raise the possibility that
greater cognitive impairment and the relative rarity of tremor may be
distinctive features worthy of further investigation. Copyright 2001 Movement
Disorder Society.
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.
Cadet, J. L. (2001). "Molecular neurotoxicological models of Parkinsonism: focus
on genetic manipulation of mice." 8(2): 85-90.
Parkinson's disease is a neurodegenerative disorder that affects mainly the
nigrostriatal dopaminergic system in humans. Several propositions have been put
forward to explain the cellular and molecular pathobiology of this syndrome.
Initial attempts were made through the use of various agents to manipulate the
deleterious effects of toxins that destroy dopaminergic cells both in vitro and
in vivo. These studies led to the idea that oxidative stress is an important
factor in killing these cells. More recent attempts have made use of genetically
modified mice to eliminate or over-express genes of interest. These experiments
have suggested that the destruction of dopaminergic cells might be the result of
the convergence of dependent and independent molecular pathways and that trigger
cellular events might lead to the demise of these dopaminergic cells.
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.
Chen, C. H., C. C. Hung, et al. (2001). "Debrisoquine 4-hydroxylase (CYP2D6)
genetic polymorphisms and susceptibility to schizophrenia in Chinese patients
from Taiwan." Psychiatr Genet 11(3): 153-5.
Debrisoquine 4-hydroxylase (CYP2D6) is one of the cytochrome P450 enzyme
families that metabolize many compounds. Polymorphic activities of debrisoquine
4-hydroxylase were suggested to be associated with some complex diseases, such
as cancer and Parkinson's disease. Schizophrenia is also a complex disorder, and
hence we are interested in understanding if the CYP2D6 gene is a susceptibility
gene for schizophrenia in Chinese. We determined the genotype and allele
frequencies of four molecular variants of CYP2D6 gene (i.e. 188C/T, 1934G/A,
2938C/T and 4268C/G) in 162 Chinese schizophrenic patients and 94 non-psychotic
control subjects from Taiwan. No significant differences of allele or genotype
frequencies of three polymorphisms (i.e. 188T/C, 2938C/T and 4268C/G) were
detected between patients and control subjects. The 1934A allele, which accounts
for the majority of poor metabolizers in Caucasians, was not detected in either
patients or control subjects, indicating that the 1934A allele is very rare in
Chinese. Our data suggest that the CYP2D6 gene may not be a susceptibility gene
for schizophrenia in Chinese schizophrenic patients.
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.
Cole, N. B., D. D. Murphy, et al. (2001). "Lipid droplet binding and
oligomerization properties of the Parkinson's disease protein alpha-synuclein."
J Biol Chem.
alpha-Synuclein is a major component of the fibrillary lesion known as Lewy
bodies (LBs) and Lewy neurites (LNs) that are the pathologic hallmarks of
Parkinson's disease (PD). In addition, point mutations in the alpha-synuclein
gene implicate alpha-synuclein dysfunction in the pathology of inherited forms
of PD. alpha-Synuclein is a member of a family of proteins found primarily in
the brain and is concentrated within presynaptic terminals. Here, we address the
localization and membrane binding characteristics of wild type and PD mutants of
alpha synuclein in cultured cells. In cells treated with high concentrations of
fatty acids, wild type alpha-synuclein accumulated on phospholipid monolayers
surrounding triglyceride-rich lipid droplets, and was able to protect stored
triglycerides from hydrolysis. PD mutant synucleins showed variable
distributions on lipid droplets and were less effective in regulating
triglyceride turnover. Chemical crosslinking demonstrated that synuclein formed
small oligomers within cells, primarily dimers and trimers, that preferentially
associated with lipid droplets and cell membranes. Our results suggest that the
initial phases of synuclein aggregation may occur on the surfaces of membranes,
and that pathological conditions that induce crosslinking of synuclein may
enhance the propensity for subsequent synuclein aggregation.
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.
Date, I., T. Shingo, et al. (2001). "Grafting of encapsulated genetically
modified cells secreting GDNF into the striatum of parkinsonian model rats."
Cell Transplant 10(4-5): 397-401.
In order to deliver glial cell line-derived neurotrophic factor (GDNF) into the
brain, we have established a cell line that produces GDNF in a continuous
fashion by genetic engineering. These cells were encapsulated and grafted into
parkinsonian model rats that had received unilateral intrastriatal injection of
6-hydroxydopamine 2 weeks earlier. Neurochemical analysis showed that GDNF has
been produced from the capsule for 6 months after grafting and histological
analysis revealed good survival of GDNF-producing cells in the capsule 6 months
after grafting. The density of nigrostriatal dopaminergic fibers in the striatum
as well as the number of dopaminergic cell bodies in the substantia nigra
recovered significantly after GDNF-producing cell grafting. These results
suggest the possible application of GDNF-producing cell grafting for the
treatment of Parkinson's disease.
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.
Doevendans, P. A. and H. J. Wellens (2001). "Wolff-Parkinson-White Syndrome: A
Genetic Disease?" Circulation 104(25): 3014-3016.
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.
Farin, F. M., P. Janssen, et al. (2001). "Genetic polymorphisms of microsomal
and soluble epoxide hydrolase and the risk of Parkinson's disease."
Pharmacogenetics 11(8): 703-8.
Oxidative stress is hypothesized to play a major role in the destruction of
dopaminergic neurons, which is associated with Parkinson's disease. Epoxides are
potentially reactive intermediates formed through the oxidative metabolism of
both exogenous and endogenous substances that contribute to cytotoxic damage
mediated by oxidative stress. The microsomal (EPHX1) and soluble (EPHX2) epoxide
hydrolases function to regulate the oxidation status of a wide range of
xenobiotic- and lipid-derived substrates; therefore, interindividual variation
in these pathways may mitigate epoxide-related cellular injury. In this
investigation, we examined the potential association between the risk of
Parkinson's disease and genetic variation within the EPHX1 and EPHX2 genes.
Fluorescent 5' nuclease-based assays were developed to identify the allelic
status of individuals with respect to specific single nucleotide polymorphisms
in exons 3 and 4 of the EPHX1 gene and exons 8 and 13 of the EPHX2 gene. EPHX1
and EPHX2 genotype data were obtained from 133 idiopathic Parkinson's disease
patients and 212 control subjects matched on age, gender and ethnicity. No
statistically significant differences were found in the distribution of the
reference and variant alleles between Parkinson's disease and control subjects,
or when results were stratified by gender. Therefore, common polymorphisms
within EPHX1 and EPHX2 do not appear to be important risk factors for
Parkinson's disease.
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.
Farrer, M., D. M. Maraganore, et al. (2001). "alpha-Synuclein gene haplotypes
are associated with Parkinson's disease." Hum Mol Genet 10(17):
1847-51.
We report haplotype analysis of the alpha-synuclein gene in Parkinson's disease
(PD), extending earlier reports of an association with a polymorphism within the
gene promoter. This analysis showed significant differences in haplotypes
between PD cases and controls. Our analyses demonstrate that genetic variability
in the alpha-synuclein gene is a risk factor for the development of PD. These
genetic findings are analogous to the tau haplotype over-represented in
progressive supranuclear palsy and further extend the similarity in the
etiologies and pathogeneses of the synucleinopathies and tauopathies.
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.
Ferrarese, C., L. Tremolizzo, et al. (2001). "Decreased platelet glutamate
uptake and genetic risk factors in patients with Parkinson's disease." Neurol
Sci 22(1): 65-6.
Genetic risk factors seem to play a role in sporadic Parkinson's disease (PD),
maybe triggering oxidative stress and excitotoxicity within substantia nigra.
However, genetic factors act at systemic level: reduced activity of
mitochondrial enzymes and decreased glutamate uptake have been shown in
platelets from PD patients. In this study we investigated glutamate uptake in
platelets from 38 sporadic PD patients, 13 patients with parkinsonian syndromes
and 28 controls and assessed polymorphisms of alpha-synuclein and ApoE genes. A
48% reduction of glutamate uptake p)<0.0001) was observed in PD patients which,
with respect to control groups, correlated with the disease severity (r = -0.44,
p < 0.05). Genetic studies of this population did not show differences between
PD and controls, nor correlations with platelet glutamate uptake.
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.
Gerlai, R., A. McNamara, et al. (2001). "Impaired water maze learning
performance without altered dopaminergic function in mice heterozygous for the
GDNF mutation." Eur J Neurosci 14(7): 1153-63.
Exogenous glial cell line-derived neurotrophic factor (GDNF) exhibits potent
survival-promoting effects on dopaminergic neurons of the nigrostriatal pathway
that is implicated in Parkinson's disease and also protects neurons in forebrain
ischemia of animal models. However, a role for endogenous GDNF in brain function
has not been established. Although mice homozygous for a targeted deletion of
the GDNF gene have been generated, these mice die within hours of birth because
of deficits in kidney morphogenesis, and, thus, the effect of the absence of
GDNF on brain function could not be studied. Herein, we sought to determine
whether adult mice, heterozygous for a GDNF mutation on two different genetic
backgrounds, demonstrate alterations in the nigrostriatal dopaminergic system or
in cognitive function. While both neurochemical and behavioural measures
suggested that reduction of GDNF gene expression in the mutant mice does not
alter the nigrostriatal dopaminergic system, it led to a significant and
selective impairment of performance in the spatial version of the Morris water
maze. A standard panel of blood chemistry tests and basic pathological analyses
did not reveal alterations in the mutants that could account for the observed
performance deficit. These results suggest that endogenous GDNF may not be
critical for the development and functioning of the nigrostriatal dopaminergic
system but it plays an important role in cognitive abilities.
Giasson, B. I. and V. M. Lee (2001). "Parkin and the molecular pathways of
parkinson's disease." Neuron 31(6): 885-8.
Parkinson's disease (PD) is a neurodegenerative disease characterized by the
selective demise of specific neuronal populations leading to impairment of motor
functions. Recent genetic studies have uncovered several genes involved in
inherited forms of the disease. These gene products are implicated in the
biochemical pathways underlying the etiology of sporadic PD. Mutations in the
parkin gene causal of autosomal recessive juvenile parkinsonism highlight that
ubiquitin-mediated proteolysis may play an important role in the pathobiology of
PD.
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.
Gollob, M. H., J. J. Seger, et al. (2001). "Novel PRKAG2 Mutation Responsible
for the Genetic Syndrome of Ventricular Preexcitation and Conduction System
Disease With Childhood Onset and Absence of Cardiac Hypertrophy." Circulation
104(25): 3030-3033.
BACKGROUND: We recently reported a mutation in the PRKAG2 gene to be responsible
for a familial syndrome of ventricular preexcitation, atrial fibrillation,
conduction defects, and cardiac hypertrophy. We now report a novel mutation in
PRKAG2 causing Wolff-Parkinson-White syndrome and conduction system disease with
onset in childhood and the absence of cardiac hypertrophy. Methods and Results-
DNA was extracted from white blood cells obtained from family members. PRKAG2
exons were amplified by polymerase chain reaction and were screened for
mutations by direct sequencing. The genomic organization of the PRKAG2 gene was
determined using inter-exon long-range polymerase chain reaction for cDNA
sequence not available in the genome database. A missense mutation, Arg531Gly,
was identified in all affected individuals but was absent in 150 unrelated
individuals. The PRKAG2 gene was determined to consist of 16 exons and is at
least 280 kb in size. CONCLUSIONS: We identified a novel mutation (Arg531Gly) in
the gamma-2 regulatory subunit (PRKAG2) of AMP-activated protein kinase (AMPK)
to be responsible for a syndrome associated with ventricular preexcitation and
early onset of atrial fibrillation and conduction disease. These observations
confirm an important functional role of AMPK in the regulation of ion channels
specific to cardiac tissue. The identification of the cardiac ion channel(s)
serving as substrate for AMPK not only would provide insight into the molecular
basis of atrial fibrillation and heart block but also may suggest targets for
the development of more specific therapy for these common rhythm disturbances.
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.
Henderson, J. M., W. P. Gai, et al. (2001). "Parkinson's disease with late
Pick's dementia." Mov Disord 16(2): 311-9.
We report a case in which typical clinical features of idiopathic Parkinson's
disease existed for seven years prior to the development of significant
behavioral and cognitive changes and severe dementia. The patient presented with
right-sided resting tremor, bradykinesia, and rigidity, which were highly
responsive to levodopa. Serial neuropsychological evaluation revealed no
evidence of dementia until late in the disease. The patient deteriorated rapidly
eight years into the disease, requiring full care. She died 16 years after
symptom onset and post-mortem neuropathological analysis revealed Lewy body
Parkinson's disease and Pick's disease. To our knowledge, this is the first
non-familial case with this combination of clinical history and pathologically
confirmed disease to be reported in the literature. The absence of a family
history of any neurological disease sets this case apart from the recently
described genetic cases of frontotemporal dementia with Parkinsonism linked to
chromosome 17. In addition, the relatively late onset of dementia in
frontotemporal dementia is atypical. While there is considerable debate
regarding the cause of dementia in idiopathic |