Wood, S. J., J. Wypych, et al. (1999). "alpha-synuclein fibrillogenesis is nucleation-dependent. Implications for the pathogenesis of Parkinson's disease." J Biol Chem274(28): 19509-12.
Parkinson's disease (PD) is a neurodegenerative disorder that is pathologically characterized by the presence of intracytoplasmic Lewy bodies, the major components of which are filaments consisting of alpha-synuclein. Two recently identified point mutations in alpha-synuclein are the only known genetic causes of PD. alpha-Synuclein fibrils similar to the Lewy body filaments can be formed in vitro, and we have shown recently that both PD-linked mutations accelerate their formation. This study addresses the mechanism of alpha-synuclein aggregation: we show that (i) it is a nucleation-dependent process that can be seeded by aggregated alpha-synuclein functioning as nuclei, (ii) this fibril growth follows first-order kinetics with respect to alpha-synuclein concentration, and (iii) mutant alpha-synuclein can seed the aggregation of wild type alpha-synuclein, which leads us to predict that the Lewy bodies of familial PD patients with alpha-synuclein mutations will contain both, the mutant and the wild type protein. Finally (iv), we show that wild type and mutant forms of alpha-synuclein do not differ in their critical concentrations. These results suggest that differences in aggregation kinetics of alpha-synucleins cannot be explained by differences in solubility but are due to different nucleation rates. Consequently, alpha-synuclein nucleation may be the rate-limiting step for the formation of Lewy body alpha-synuclein fibrils in Parkinson's disease.
Wakabayashi, K., M. Yoshimoto, et al. (1999). "Widespread occurrence of alpha-synuclein/NACP-immunoreactive neuronal inclusions in juvenile and adult-onset Hallervorden-Spatz disease with Lewy bodies." Neuropathol Appl Neurobiol25(5): 363-8.
Alpha-Synuclein (originally called precursor of the non-Abeta component of Alzheimer's disease amyloid-NACP) is a presynaptic nerve terminal protein and is now known to be a major component of Lewy bodies (LBs) in Parkinson's disease. Previous studies have shown that LBs are occasionally found in patients with Hallervorden-Spatz disease (HSD), a hereditary or sporadic neuroaxonal dystrophy. Therefore, an immunocytochemical examination of the brain tissues from two patients with HSD for alpha-synuclein/NACP was performed. In both cases, LBs were observed in the substantia nigra, locus ceruleus and other subcortical nuclei. These LBs were strongly immunolabelled with anti-alpha-synuclein/NACP. Moreover, abnormal alpha-synuclein/NACP-immunoreactive structures in the neuronal somata and processes were found in the cerebral neocortex, hippocampus, basal ganglia, thalamus, pontine and inferior olivary nuclei, spinal grey matter, and peripheral sympathetic ganglia. Although numerous dystrophic axons (spheroids) were found throughout the brain, either none or only a few were positive for alpha-synuclein/NACP. These findings suggest that widespread accumulation of alpha-synuclein/NACP is a pathological feature in patients suffering from HSD with LBs, and that this phenomenon is unrelated to axonal spheroid formation.
Wakabayashi, K., Y. Toyoshima, et al. (1999). "Restricted occurrence of Lewy bodies in the dorsal vagal nucleus in a patient with late-onset parkinsonism." J Neurol Sci165(2): 188-91.
Lewy body (LB) is consistently found in the substantia nigra in Parkinson's disease. We report a 68-year-old woman with late-onset, dopa-responsive parkinsonism. Her parents were first cousins, but no other affected individuals were present in the family. Autopsy revealed moderate loss of pigmented neurons with gliosis, but neither LBs nor neurofibrillary tangles in the substantia nigra. The locus ceruleus showed neuronal loss with scarce LBs. The most striking change was found in the dorsal vagal nucleus, where marked neuronal loss and fibrillary gliosis with many LBs were evident. Despite the use of ubiquitin and alpha-synuclein immunohistochemistry, no further LBs were identified in other brain regions. These findings suggest that this case was an unusual, anatomically restricted manifestation of LB disease.
Wakabayashi, K., I. Kawachi, et al. (1999). "[Occurrence of argyrophilic grains in multiple system atrophy: histopathological examination of 26 autopsy cases]." No To Shinkei51(5): 433-7.
Argyrophilic grain disease (AGD) is a progressive disorder producing dementia in elderly individuals characterized by the presence of numerous AGs in the limbic system. However, the occurrence of AGs has been reported in other neurodegenerative conditions including Alzheimer's disease, Pick's disease, progressive supranuclear palsy and corticobasal degeneration, all of which show tau-positive cytoskeletal abnormalities. We examined the brains of 26 patients with multiple system atrophy (MSA), a neurodegenerative disorder fundamentally lacking tau pathology, histologically and immunocytochemically. Numerous AGs were found in the limbic system in 5 patients, of whom two had shown mild dementia. Immunocytochemically, these AGs were labeled with antibodies against phosphorylation-dependent and -independent tau protein, but not alpha-synuclein, whereas oligodendroglial cytoplasmic inclusions found exclusively in MSA were immunoreactive for alpha-synuclein and, less consistently, for phosphorylation-independent tau but not for phosphorylation-dependent tau protein. Furthermore, many phosphorylation-dependent tau-positive neurons and significant numbers of ballooned neurons (BNs) were found in the limbic system in all of the 5 patients with AGs. These findings suggest that AGs can occur with relatively high frequency in the limbic system of MSA patients, and that as in AGD, they may be accompanied by tau-positive neurons and BNs.
van Duinen, S. G., G. J. Lammers, et al. (1999). "Numerous and widespread alpha-synuclein-negative Lewy bodies in an asymptomatic patient." Acta Neuropathol (Berl)97(5): 533-9.
Lewy bodies (LB) and pale bodies (PB), their putative precursors, can be found in a spectrum of diseases characterized by parkinsonism and/or dementia. Furthermore, LB are occasionally observed in some other neurodegenerative diseases and in normal aging. Classical LB are typically found in the brain stem, especially in the substantia nigra, where these inclusions are associated with neuronal loss and clinical signs of idiopathic Parkinson's disease (PD). The so-called cortical LB occur in the cerebral cortex, amygdala and claustrum with little or no neuronal loss and are clinically associated with dementia in dementia with LB (DLB). We describe a patient without apparent clinical signs of parkinsonism and/or dementia, whose brain contained numerous classical-like LB, pale inclusions with features of PB and transitions between these two. These inclusions had similar immunohistological (ubiquitin positive; neurofilament positive; tau negative) and ultrastructural features as the LB in PD and DLB except for the lack of immunoreactivity for alpha-synuclein. The pons and cerebral cortex showed the highest number of LB, up to 165/1.76 mm2. These numbers were contrasted by the lack of obvious neuronal loss or gliosis. The absence of alpha-synuclein reactivity in the LB in this symptomless patient corroborates the hypothesis that alpha-synuclein accumulation in LB is an important step in neurodegeneration in PD and DLB, but tones down the role of alpha-synuclein in LB formation in general. This patient seems to represent a new variant in the spectrum of diseases associated with LB.
Trojanowski, J. Q. and V. M. Lee (1999). "Transgenic models of tauopathies and synucleinopathies." Brain Pathol9(4): 733-9.
Rapidly emerging concepts about the pathobiology and defining phenotypes of two major classes of neurodegenerative disease known as tauopathies and synucleinopathies are bringing these diseases into shaper focus. Significantly, recent research has substantially advanced understanding of these neurodegenerative disorders thereby providing fresh opportunities for the development of transgenic (TG) mouse models. Since the availability of such animal models will accelerate efforts to discover more effective therapies, we review the current status of efforts to generate informative TG mouse models for tauopathies and synucleinopathies and other neurodegenerative disorders characterized by prominent filamentous brain lesions.
Takanashi, M., T. Urabe, et al. (1999). "[A 73-year-old woman with familial Parkinson's disease]." No To Shinkei51(12): 1087-96.
We report a 73-year-old Japanese woman with familial Parkinson's disease. The patient was well until her 67 years of the age, when she noted rest tremor in her right hand. Soon after her gait became short stepped. She visited our clinic on October 6, 1992 when she was 68 years old. She was alert and well oriented without dementia. She showed masked face, small voice, small stepped gait, retropulsion, resting tremor in her right hand, rigidity in the neck, and bradykinesia. She was treated with 400 mg/day of levodopa-carbidopa, which improved her symptoms, however, she developed wearing off phenomenon 3 years after the initiation of levodopa treatment. On August 26, 1998, she developed abdominal pain, diarrhea, and vomiting. She was admitted to another hospital, where abdominal plain x-ray revealed an evidence of intestinal obstruction (ileus). She was treated with nasogastric suction and intravenous fluid. Her condition did not improve and she was transferred to our hospital on August 29, 1998. Her family history revealed no consanguineous marriage. She had two elder brothers and three elder sisters. One of her brothers had been diagnosed as Parkinson's disease. Her husband also suffered from Parkinson's disease, however, her parents apparently did not have Parkinson's disease. On admission, she appeared to be drowsy. Her blood pressure was 102/70 mmHg, body temperature 36.2 degrees C. The lungs were clear and no cardiac murmur was present. Abdomen was flat and bowel sound was audible. No abnormal mass was palpable. Neurologic examination revealed mild consciousness disturbance, masked face, and small voice. No motor paralysis was noted. Muscle tone was hypotonic. No abnormal involuntary movement was noted. Abnormal laboratory findings on admission were as follows; WBC 11,300/microliter, amylase 1,373 IU/l, CK 446 IU/l, BUN 50 mg/dl, creatinine 1.17 mg/dl, CRP 22.7 mg/ dl, Na 134 mEq/l, K 3.1 mEq/l, and Cl 81 mEq/l. A chest x-ray film revealed pneumonic shadows in both lower lung fields. She was treated by nasointestinal suction, intravenous fluids, and chemotherapy for her infection. Her BP started to drop on September 2 and she developed cardiac arrest on the same day. She was discussed in a neurological CPC. The chief discussant arrived at the conclusion that the patient had a form of autosomal dominant familial Parkinson's disease. As parents did not have Parkinson's disease, some of the participants raised the possibility of autosomal recessive inheritance. But the age of onset was too late for autosomal recessive inheritance. Majority thought that the mode of inheritance was autosomal dominant with low penetrance. alpha-Synuclein mutation causes an autosomal dominant familial Parkinson's disease, but this type is very rare in non-Greek populations and the penetrance is high. Chromosome 2-linked autosomal dominant familial Parkinson's disease shows low penetrance. There are many other autosomal dominant forms of familial Parkinson's disease linked to yet unknown chromosome loci. Majority thought that this patient also had a form of Lewy-body positive autosomal dominant familial Parkinson's disease of unknown chromosome locus. Post mortem examination revealed ischemic intestinal lesion with strangulation. This was thought to be the cause of her death. In the central nervous system, the brain appeared to be normal by inspection. In the coronal sections, the substantia nigra and the locus coeruleus showed marked depigmentation. Histologic examination revealed marked neuronal loss and Lewy body formation in the remaining neurons. Pathologic examination was consistent with Parkinson's disease. Mutational analysis for the parkin gene was negative.
Surguchov, A., I. Surgucheva, et al. (1999). "Synoretin--A new protein belonging to the synuclein family." Mol Cell Neurosci13(2): 95-103.
Aoffa-Synuclein, a presynaptic nerve terminal protein, may be an important component of Lewy bodies in Parkinson's disease, dementia with Lewy bodies, and other neurodegenerative diseases. Additionally, recent genetic studies based on linkage analysis and cosegregation of A53T and A30P missense mutations demonstrated that the alpha-synuclein gene may be responsible for the development of at least some cases of familial Parkinson's disease. Despite intense interest in the members of the synuclein family, their function(s) and exact role in the diseases remained unknown. Here we describe a new member of the synuclein family, which we term synoretin, and show that it is expressed in different retinal cells, as well as in the brain, and it may affect the regulation of signal transduction through activation of the Elk1 pathway.
Spillantini, M. G., M. Tolnay, et al. (1999). "Microtubule-associated protein tau, heparan sulphate and alpha-synuclein in several neurodegenerative diseases with dementia." Acta Neuropathol (Berl)97(6): 585-94.
Microtubule-associated protein tau forms neurofibrillary lesions in Alzheimer's disease and several other neurodegenerative disorders, such as Niemann-Pick disease type C, subacute sclerosing panencephalitis, argyrophilic grain disease, myotonic dystrophy and motor neuron disease with neurofibrillary tangles. In this study we have compared the characteristics of tau pathology in these diseases using immunohistochemistry and phosphorylation-dependent and phosphorylation-independent anti-tau antibodies. The pattern of staining for heparan sulphate and alpha-synuclein was also investigated. We show that in all of these diseases tau deposits were stained by all anti-tau antibodies used, with the exception of argyrophilic grains which do not stain with antibody 12E8, confirming our previous findings. Heparan sulphate staining was present to a variable extent in all of these diseases, with the exception of subacute sclerosing panencephalitis, in which no staining was observed. Heparan sulphate staining coexisted with tau staining. In some cases it was more extensive than the tau staining. Alpha-synuclein staining was present in presynaptic terminals with the exception of one case of Alzheimer's disease, in which alpha-synuclein-positive Lewy bodies were observed in the hippocampal formation. These findings indicate that tau deposits are antigenically similar in several neurodegenerative diseases and that tau staining is often associated with heparan sulphate staining, supporting the concept that heparan sulphate may be involved in the assembly of tau protein into filaments.
Scott, W. K., L. H. Yamaoka, et al. (1999). "The alpha-synuclein gene is not a major risk factor in familial Parkinson disease." Neurogenetics2(3): 191-2.
Schulz, J. B. and J. Dichgans (1999). "Molecular pathogenesis of movement disorders: are protein aggregates a common link in neuronal degeneration?" Curr Opin Neurol12(4): 433-9.
Abnormal protein aggregation has been postulated to explain the molecular basis for many neurodegenerative diseases, including Alzheimer's disease, Parkinson's disease and prion diseases, as well as trinucleotide repeat disorders. The recent findings that mutations in alpha-synuclein lead to autosomal-dominant, early-onset Parkinson's disease in some families and that alpha-synuclein is found in Lewy bodies of all Parkinson's disease patients prompted the hypothesis that the pathophysiology of all Parkinson's disease patients starts with an abnormal folding of alpha-synuclein, producing excessive aggregation that overwhelms the antiaggregation mechanisms of the cell. The genetics of Parkinson's disease and polyglutamine repeat disorders and the evidence of abnormal processing and aggregation of the respective target proteins for the aetiology and pathogenesis in these diseases are reviewed.
Schraen-Maschke, S., S. Brique, et al. (1999). "Analysis of ERDA1, CTG18.1, and uncloned CAG/CTG repeat sequences in familial Parkinson's disease with anticipation." Am J Med Genet88(6): 738-41.
In several neurodegenerative diseases, anticipation or increase in disease severity in succeeding generations within families correlates with expansions of an intragenic CAG/CTG repeat sequence above the normal range through the generations of a pedigree. Some kindreds of familial Parkinson's disease (PD) exhibit genetic anticipation. We used the repeat expansion detection (RED) method to detect repeat expansions directly in DNA samples from the index cases of 34 different PD families with anticipation. The mean age at onset of the younger probands was 48.8 +/- 10.8 years and the mean intergenerational difference was 19.2 +/- 10 years. The distribution of the RED products greater than 40 repeats was not significantly different between patients and controls with the Mann-Whitney U test (U = 510.5, p = 0.67). The samples were then screened for the two expanded-repeat loci, ERDA1 and CTG18.1. We found that in all cases the repeat expansion detected by the RED method may be accounted for by an expansion at these loci. Our results demonstrate that unstable CAG/CTG expansions corresponding to uncloned or cloned sequences (ERDA1, CTG18.1) are not involved in the etiology of rare familial case of PD with genetic anticipation. Am. J. Med. Genet. (Neuropsychiatr. Genet.) 88:738-741, 1999 Copyright 1999 Wiley-Liss, Inc.
Sandmann-Keil, D., H. Braak, et al. (1999). "Alpha-synuclein immunoreactive Lewy bodies and Lewy neurites in Parkinson's disease are detectable by an advanced silver-staining technique." Acta Neuropathol (Berl)98(5): 461-4.
Immunostaining with anti-alpha-synuclein is used to detect Lewy bodies and Lewy neurites in cases of Parkinson's disease and related disorders. To prove that the result of a modern silver method is equivalent to that achieved with immunoreactions for alpha-synuclein, individual sections were successively processed using both methods. The silver-stained sections showed all of the immunoreactive Lewy bodies, and thin Lewy neurites were detected equally well by both techniques. The present study, therefore, points to the capabilities of a modern silver-staining method which is less time consuming and less expensive than immunocytochemical techniques.
Samii, A., K. Markopoulou, et al. (1999). "PET studies of parkinsonism associated with mutation in the alpha-synuclein gene." Neurology53(9): 2097-102.
OBJECTIVE: To assess the pattern of dopaminergic abnormalities in a Greek-American kindred (family H) with autosomal dominantly inherited, levodopa-responsive parkinsonism caused by a mutation of the gene encoding alpha-synuclein. BACKGROUND: Mutations of alpha-synuclein have been associated recently with dominantly inherited, levodopa-responsive parkinsonism. The pattern of dopamine deficiency and status of postsynaptic dopamine receptors in this condition have not been reported previously. The authors followed a large, six-generation family in whom the affected members carry the recently reported G209A mutation in the gene encoding alpha-synuclein. METHODS: The authors studied four affected and two clinically unaffected gene-negative members of family H using [18F]-6-fluoro-L-dopa (FD) and [11C]-raclopride (RAC) PET to assess presynaptic dopaminergic function and dopamine D2 receptors. The results were compared with normal subjects and patients with sporadic, idiopathic PD (IP). RESULTS: In affected individuals, FD uptake was reduced in both the caudate and the putamen, but the putamen was affected more severely than the caudate, as seen in IP. RAC binding was within the normal range, but the ratio of RAC binding in the putamen to that in the caudate was increased in affected members of family H. This pattern is similar to that seen in IP. CONCLUSIONS: PET of the nigrostriatal system in parkinsonism associated with a mutation in the ac-synuclein gene indicates that it results in a pattern of dopamine deficiency, with preserved D2 binding, indistinguishable from IP.
Saito, M. (1999). "[Hereditary Parkinson's disease mapped to chromosome 4q21-q23]." Ryoikibetsu Shokogun Shirizu(27 Pt 2): 24-6.
Riess, O. and R. Kruger (1999). "Parkinson's disease--a multifactorial neurodegenerative disorder." J Neural Transm Suppl56: 113-25.
The pathogenesis of idiopathic Parkinson's disease (PD) is not known, but is thought to be multifactorial, deriving from environmental factors acting on genetically predisposed individuals with aging. Association studies of DNA polymorphisms are able to detect a genetic background predisposing to PD. Mechanisms as oxidative stress, xenobiotica toxicity and altered dopamine metabolism might lead to a selective cell death of most vulnerable nerve cells and represent the primary subject to be studied by DNA analysis. Furthermore, protein aggregation is likely to be a major cause for the disease. Recently it has been shown that alpha-synuclein is accumulated in Lewy bodies of sporadic PD and mutated in some rare families with an autosomal dominant trait of the disease (ADPD). The identification of further genes responsible for PD will subsequently lead to first insights into the pathogenesis of one of the most common neurodegenerative disorders in humans.
Prasad, K. N., W. C. Cole, et al. (1999). "Multiple antioxidants in the prevention and treatment of Parkinson's disease." J Am Coll Nutr18(5): 413-23.
Parkinson's disease (PD) is one of the major progressive neurological disorders for which no preventative or long-term effective treatment strategies are available. Epidemiologic studies have failed to identify specific environmental, dietary or lifestyle risk factors for PD except for toxic exposure to manganese, meperidine (Demerol, the "designer drug" version of which often contains a toxic byproduct of the synthesis, 1-methyl-4-phenyl 1,2,3,6 tetrahydropyridine [MPTP]), and some herbicides and pesticides. The search for genetic risk factors such as mutation, overexpression or underexpression of nuclear genes in DA neurons in idiopathic PD has not been successful as yet. Polymorphism in certain genes appears to be a risk factor, but there is no direct evidence for the causal relationship between polymorphism and increased risk of PD. In familial PD, mutation in the alpha-synuclein gene is associated with the disease, but a direct role of this gene in degeneration of DA neurons remains to be established. Although mutations in the Parkin gene has been associated with autosomal recessive juvenile Parkinson's disease, the role of this gene mutation in causing degeneration of DA neurons has not been defined. We have reported that in hereditary PD, a mutation in the alpha-synuclein gene may increase the sensitivity of DA neurons to neurotoxins. We hypothesize that, in idiopathic PD, epigenetic (mitochondria, membranes, protein modifications) rather than genetic events are primary targets which, when impaired, initiate degeneration in DA neurons, eventually leading to cell death. Although the nature of neurotoxins that cause degeneration in DA neurons in PD is not well understood, oxidative stress is one of the intermediary risk factors that could initiate and/or promote degeneration of DA neurons. Therefore, supplementation with antioxidants may prevent or reduce the rate of progression of this disease. Supplementation with multiple antioxidants at appropriate doses is essential because various types of free radicals are produced, antioxidants vary in their ability to quench different free radicals and cellular environments vary with respect to their lipid and aqueous phases. L-dihydroxyphenylalanine (L-dopa) is one of the agents used in the treatment of PD. Since L-dopa is known to produce free radicals during its normal metabolism, the combination of L-dopa with high levels of multiple antioxidants may improve the efficacy of L-dopa therapy.
Petersen, G. and H. S. Hansen (1999). "N-acylphosphatidylethanolamine-hydrolysing phospholipase D lacks the ability to transphosphatidylate." FEBS Lett455(1-2): 41-4.
The N-acylphosphatidylethanolamine-hydrolysing phospholipase D (NAPE-PLD) generates N-acylethanolamines, including N-arachidonoyl-ethanolamine (anandamide), that may be neuroprotective and analgesic. The properties of NAPE-PLD from rat heart and brain microsomes are investigated and compared to those of other PLDs. NAPE-PLD is inhibited by the fatty acid aminohydrolase inhibitor MAFP in high concentrations (> or = 100 microM) while PMSF in high concentrations (10 mM) tends to stabilise NAPE-PLD activity. Oleate inhibits NAPE-PLD but the enzyme is not affected by PIP2, alpha-synuclein or mastoparan. Furthermore, it is for the first time reported that NAPE-PLD is not capable of catalysing a transphosphatidylation reaction like most other known PLDs.
Petersen, K., O. F. Olesen, et al. (1999). "Developmental expression of alpha-synuclein in rat hippocampus and cerebral cortex." Neuroscience91(2): 651-9.
Alpha-synuclein is an evolutionary highly conserved neuronal protein localized in presynaptic nerve terminals. The protein has been suggested to be involved in the pathogenesis of neurodegenerative diseases, but little is known about the physiological function of the protein. In the present study we used newborn, three, 14, 93 and 710-day-old rats to examine the expression of alpha-synuclein messenger RNA and protein during development of the hippocampus and cerebral cortex. Using in situ hybridization and an S1 nuclease protection assay, we found a high expression of alpha-synuclein messenger RNA during early postnatal development, followed by a marked decrease between postnatal days 14 and 93. In contrast, the amount of alpha-synuclein protein, as determined by immunoblotting, continued to increase throughout development and remained at a high level for at least two years. The persistent high expression of alpha-synuclein protein throughout development suggests that the protein is involved in maintaining synaptic function. Furthermore, the discrepancy between the levels of alpha-synuclein messenger RNA and protein after postnatal day 14 indicates that the amount of alpha-synuclein is determined by post-transcriptional regulation, and not by messenger RNA expression alone. To estimate the changes of alpha-synuclein expression per synapse, we compared the developmental expression of alpha-synuclein with synaptophysin, a well-established synaptic marker. The alpha-synuclein/synaptophysin messenger RNA and protein ratio was high during early development, but low in adult (postnatal day 93) and old (postnatal day 710) rats. This could indicate a higher expression of alpha-synuclein per synapse during early development.
Papadimitriou, A., V. Veletza, et al. (1999). "Mutated alpha-synuclein gene in two Greek kindreds with familial PD: incomplete penetrance?" Neurology52(3): 651-4.
The G209A mutation in the alpha-synuclein gene has been associated with autosomal dominant PD (ADPD) in a family from Contursi, Italy, and three apparently unrelated Greek families. Several groups around the world failed to identify the G209A mutation in a sizable series of familial and sporadic cases of PD. The authors present two additional Greek families with ADPD associated with the G209A mutation. In both families, asymptomatic carriers older than the expected age at onset were found.
Paik, S. R., H. J. Shin, et al. (1999). "Copper(II)-induced self-oligomerization of alpha-synuclein." Biochem J340 ( Pt 3): 821-8.
alpha-Synuclein is a component of the abnormal protein depositions in senile plaques and Lewy bodies of Alzheimer's disease (AD) and Parkinson's disease respectively. The protein was suggested to provide a possible nucleation centre for plaque formation in AD via selective interaction with amyloid beta/A4 protein (Abeta). We have shown previously that alpha-synuclein has experienced self-oligomerization when Abeta25-35 was present in an orientation-specific manner in the sequence. Here we examine this biochemically specific self-oligomerization with the use of various metals. Strikingly, copper(II) was the most effective metal ion affecting alpha-synuclein to form self-oligomers in the presence of coupling reagents such as dicyclohexylcarbodi-imide or N-(ethoxycarbonyl)-2-ethoxy-1,2-dihydroquinoline. The size distribution of the oligomers indicated that monomeric alpha-synuclein was oligomerized sequentially. The copper-induced oligomerization was shown to be suppressed as the acidic C-terminus of alpha-synuclein was truncated by treatment with endoproteinase Asp-N. In contrast, the Abeta25-35-induced oligomerizations of the intact and truncated forms of alpha-synuclein were not affected. This clearly indicated that the copper-induced oligomerization was dependent on the acidic C-terminal region and that its underlying biochemical mechanism was distinct from that of the Abeta25-35-induced oligomerization. Although the physiological or pathological relevance of the oligomerization remains currently elusive, the common outcome of alpha-synuclein on treatment with copper or Abeta25-35 might be useful in understanding neurodegenerative disorders in molecular terms. In addition, abnormal copper homoeostasis could be considered as one of the risk factors for the development of disorders such as AD or Parkinson's disease.
Ozawa, T., H. Takano, et al. (1999). "No mutation in the entire coding region of the alpha-synuclein gene in pathologically confirmed cases of multiple system atrophy." Neurosci Lett270(2): 110-2.
To determine whether mutations in the coding region of the alpha-synuclein gene are relevant in cases of multiple system atrophy (MSA), detailed nucleotide sequence analysis of the alpha-synuclein gene was performed using total RNA obtained from autopsied brain specimens of 11 pathologically confirmed cases of MSA. The brain specimens used in this study contained both gray and white matter, which were dissected from the frontal, temporal or occipital lobe. No nucleotide alterations were found in the entire coding region of the alpha-synuclein gene in any of the cases. While mutations in the regulatory or intronic regions of the gene were not ruled out, our results suggest that mutations in the coding region of the alpha-synuclein gene are unlikely to contribute to the pathogenesis of MSA.
Ostrerova, N., L. Petrucelli, et al. (1999). "alpha-Synuclein shares physical and functional homology with 14-3-3 proteins." J Neurosci19(14): 5782-91.
alpha-Synuclein has been implicated in the pathophysiology of many neurodegenerative diseases, including Parkinson's disease (PD) and Alzheimer's disease. Mutations in alpha-synuclein cause some cases of familial PD (Polymeropoulos et al., 1997; Kruger et al., 1998). In addition, many neurodegenerative diseases show accumulation of alpha-synuclein in dystrophic neurites and in Lewy bodies (Spillantini et al., 1998). Here, we show that alpha-synuclein shares physical and functional homology with 14-3-3 proteins, which are a family of ubiquitous cytoplasmic chaperones. Regions of alpha-synuclein and 14-3-3 proteins share over 40% homology. In addition, alpha-synuclein binds to 14-3-3 proteins, as well as some proteins known to associate with 14-3-3, including protein kinase C, BAD, and extracellular regulated kinase, but not Raf-1. We also show that overexpression of alpha-synuclein inhibits protein kinase C activity. The association of alpha-synuclein with BAD and inhibition of protein kinase C suggests that increased expression of alpha-synuclein could be harmful. Consistent with this hypothesis, we observed that overexpression of wild-type alpha-synuclein is toxic, and overexpression of alpha-synuclein containing the A53T or A30P mutations exhibits even greater toxicity. The activity and binding profile of alpha-synuclein suggests that it might act as a protein chaperone and that accumulation of alpha-synuclein could contribute to cell death in neurodegenerative diseases.
Nukina, N. (1999). "[Neuronal cell death--what we can see and what we cannot]." Rinsho Shinkeigaku39(1): 2-3.
Recently several responsible genes for hereditary neurodegenerative disorders were identified. In some of them the gene products were found to be aggregated. In the case of Alzheimer disease beta protein and apolipoprotein E accumulated in senile plaques. In CAG repeat diseases the polyglutamine aggregates in neuronal nuclei. More recently alpha synuclein accumulates in Lewy bodies in Parkinson disease and tau protein accumulates in NFT of hereditary frontotemporal dementia with tau mutation. Those results suggested that the responsible gene products accumulates in the lesion which the products involve in. However, presenilin which is one of the genes for familial Alzheimer disease accumulates in NFT and on the other hand its mutation changes the production ratio of beta 1-42/40, suggesting that the abnormal gene products not simply accumulate the lesion that it involved. The gene products accumulate in different lesions such as in nuclei of polyglutamine diseases, extracellular plaque and cytoplasm of prion disease and extracellular plaques in Alzheimer disease. Some of them are ubiquitinated and some of them are not. Thus the accumulating process in these disorders seems apparently same but is essentially different. We should study more precisely each pathological process of those disorders.
Ninkina, N. N., E. M. Privalova, et al. (1999). "Developmentally regulated expression of persyn, a member of the synuclein family, in skin." Exp Cell Res246(2): 308-11.
Synucleins constitute a group of unique, evolutionarily conserved proteins that are expressed predominantly in neurons of the central and peripheral nervous system. Although the normal cellular functions of synucleins are not clear, these proteins have been implicated in various neurodegenerative conditions in humans. We found that persyn, a recently characterized member of the synuclein family, is expressed not only in the nervous system but also in the stratum granulosum of the epidermis of neonatal and adult mice. This finding together with our recent observations that persyn influences neurofilament network integrity in sensory neurons raises the possibility that persyn in skin could be involved in modulation of the keratin network.
Neystat, M., T. Lynch, et al. (1999). "Alpha-synuclein expression in substantia nigra and cortex in Parkinson's disease." Mov Disord14(3): 417-22.
Mutations in the human alpha-synuclein gene have been identified in several families of European descent with early-onset Parkinson's disease (PD). We sequenced the complete alpha-synuclein cDNA from substantia nigra and cortex from nine patients with PD and eight control subjects. No mutations were found. We then analyzed alpha-synuclein mRNA levels using a ribonuclease protection assay. Two major protected bands of alpha-synuclein mRNA, possibly representing two splice variants of the gene, were observed. Alpha-synuclein mRNA was significantly diminished in the substantia nigra of patients with PD compared with control subjects but not in the cortex. Our findings suggest that decreased synuclein mRNA may be an early alteration in the SN in PD, and imply that decreased levels of the protein may play a role in the pathogenesis of sporadic cases of the disease.
Newell, K. L., P. Boyer, et al. (1999). "Alpha-synuclein immunoreactivity is present in axonal swellings in neuroaxonal dystrophy and acute traumatic brain injury." J Neuropathol Exp Neurol58(12): 1263-8.
The primary neuroaxonal dystrophies (NAD), which include infantile NAD and Hallervorden-Spatz syndrome (HSS), are characterized by dystrophic terminal axons and axonal swellings. Lewy bodies have been found in some cases. In Parkinson disease (PD) and dementia with Lewy bodies (DLB), Lewy bodies and neurites display prominent alpha-synuclein immunoreactivity. We examined 2 cases of HSS and 4 cases of infantile NAD with alpha-synuclein immunohistochemistry to test the hypothesis that these disorders with similar morphological findings might share a biochemical phenotype. Furthermore, we compared them to 8 cases of secondary or physiologic NAD of various causes and 2 cases of recent traumatic head injury. Alpha-synuclein positive neuronal cytoplasmic inclusions, including Lewy bodies, and neurites were numerous in 1 HSS and 1 infantile NAD case. In addition, axonal spheroids were immunostained in all 6 cases of primary NAD, 5 cases of secondary NAD, and 2 cases of recent head injury. Axonal spheroids were faintly stained in the 3 physiologic NAD cases. Alpha-synuclein positive axonal swellings may suggest a mechanism, such as axonal injury, leading to the neuronal cytoplasmic accumulation of alpha-synuclein in NAD and other disorders.
Narhi, L., S. J. Wood, et al. (1999). "Both familial Parkinson's disease mutations accelerate alpha-synuclein aggregation." J Biol Chem274(14): 9843-6.
Parkinson's disease (PD) is a neurodegenerative disorder that is pathologically characterized by the presence of intracytoplasmic Lewy bodies, the major component of which are filaments consisting of alpha-synuclein. Two recently identified point mutations in alpha-synuclein are the only known genetic causes of PD, but their pathogenic mechanism is not understood. Here we show that both wild type and mutant alpha-synuclein form insoluble fibrillar aggregates with antiparallel beta-sheet structure upon incubation at physiological temperature in vitro. Importantly, aggregate formation is accelerated by both PD-linked mutations. Under the experimental conditions, the lag time for the formation of precipitable aggregates is about 280 h for the wild type protein, 180 h for the A30P mutant, and only 100 h for the A53T mutant protein. These data suggest that the formation of alpha-synuclein aggregates could be a critical step in PD pathogenesis, which is accelerated by the PD-linked mutations.
Munoz, D. G. (1999). "Stains for the differential diagnosis of degenerative dementias." Biotech Histochem74(6): 311-20.
Our understanding of the structural substrates underlying the dementia syndrome has been transformed by the introduction of the Gallyas silver stain and the application of immunostains for tau, ubiquitin, and alpha-synuclein. Visualization of sequential changes in Alzheimer's disease and the recognition of a new substrate for dementia and dementia with argyrophilic grains, are two of the advances related to the application of the Gallyas method. The specificity of alpha-synuclein for recognizing Lewy bodies enables the unequivocal diagnosis of dementia with Lewy bodies. The diverse entities that constitute the Pick complex can be identified by applying immunostains for tau and ubiquitin in addition to the Gallyas silver stain.
Mizutani, T. (1999). "[Familial parkinsonism and dementia with ballooned neurons, argyrophilic neuronal inclusions, atypical neurofibrillary tangles, tau-negative astrocytic fibrillary tangles, and Lewy bodies]." Rinsho Shinkeigaku39(12): 1262-3.
We reported a new type of familial Parkinson's disease (familial PD) previously. After that, we examined this family by both the immunohistochemical staining using anti-alpha-synuclein antibody and the analysis of alpha-synuclein gene. We reported these results, and briefly reviewed both familial PD and "familial frontotemporal dementia and parkinsonism linked to chromosome 17 (FTDP-17)". Immunohistochemical staining with anti-alpha-synuclein antibody revealed that the argyrophilic neuronal inclusions and atypical barely tau-positive neurofibrillary tangles were strongly immunoreactive, whereas the ballooned neurons and astrocytic fibrillary tangles were unreactive. DNA analysis of the leukocytes obtained from one live patient of our family did not show any mutations in the entire exons of alpha-synuclein gene. Our results indicated that our family had familial diffuse Lewy body disease with atypical features and without alpha-synuclein gene abnormalities. Features of familial PD included 1) autosomal dominant inheritance, 2) not uncommon atypical clinical features, 3) variable symptomatology and dopa-responsiveness, and 4) low incidence of alpha-synuclein gene abnormalities. Our familial PD showed similar features, and neuropathological findings of our patients also resembled FTPD-17 in the presence of frequent ballooned neurons and neurofibrillary tangles in the cerebral cortex, but were different in the presence of Lewy bodies and paucity of tau pathology.
Mizuno, Y., N. Hattori, et al. (1999). "Genetics of Parkinson's disease." Biomed Pharmacother53(3): 109-16.
Here we review familial Parkinson's disease from clinical, as well as molecular genetic aspects. To date, two genes responsible for familial Parkinson's disease have been identified: one is the alpha-synuclein gene located in the long arm of chromosome 4, and the other is the parkin gene located in the long arm of chromosome 6. The mode of inheritance of the former is autosomal dominant and clinical features consist of levodopa-responsive parkinsonism; the age of onset is younger than that of the sporadic cases (in their 40s), and the progression is faster (average disease duration approximately nine years). The latter form is transmitted as an autosomal recessive, and clinical features consist of early onset (in their 20s), levodopa-responsive parkinsonism, and a slow progression of the disease. In addition, the tau gene has been shown to be the disease gene for familial frontotemporal dementia and parkinsonism linked to chromosome 17. There are many other clinical phenotypes of familial Parkinson's disease among which three forms have been mapped to certain chromosome loci: one is in the short arm of chromosome 2, the two other forms are in the different loci of the short arm of chromosome 4. All of them are transmitted as autosomal dominant traits manifesting levodopa responsive parkinsonism. There still exists however, other clinical phenotypes of chromosome loci which are not known. Molecular cloning of these familial Parkinson's disease genes and the elucidation of the functions of the proteins encoded will certainly contribute greatly to the investigation of the etiology and pathogenesis of more common sporadic form of Parkinson's disease.
McKeith, I. G., E. K. Perry, et al. (1999). "Report of the second dementia with Lewy body international workshop: diagnosis and treatment. Consortium on Dementia with Lewy Bodies." Neurology53(5): 902-5.
BACKGROUND/OBJECTIVE: The second International Workshop of the Consortium on Dementia with Lewy Bodies (DLB) met to review developments since publication of consensus guidelines for the clinical and pathologic diagnosis of DLB in 1996. The specificity of a clinical diagnosis of probable DLB, made using consensus criteria, is generally high (>85%), but sensitivity of case detection is lower and more variable. Inter-rater reliability for the core clinical features-recurrent visual hallucinations and spontaneous motor features of parkinsonism-is acceptable, but reliable identification of fluctuating cognition remains problematic. Depression and REM sleep behavior disorder may be additional features supportive of a diagnosis of DLB that were not included in the original guideline. RESULTS: It is recommended that the clinical consensus criteria continue to be used in their current format with research efforts focused on increasing sensitivity of case detection. Antiubiquitin immunocytochemistry is the method of choice for routine detection of Lewy bodies for diagnostic purposes in research and clinical practice. The use of alpha-synuclein antibodies to label Lewy bodies and Lewy neurites represents a major methodologic advance since the first DLB workshop. alpha-Synuclein-based methods are likely to be most useful in research laboratories, particularly for clinicopathologic correlative studies. CONCLUSION: Clinical management of DLB patients usually centers on the treatment of noncognitive features. There is now a pressing need to establish appropriately designed randomized controlled trials in DLB. Collaboration between dementia and movement disorder specialists is essential for rapid progress in research and clinical management protocols.
Matsumine, H. (1999). "[A Parkin gene (PARK 2) and Parkinson's disease]." Rinsho Shinkeigaku39(1): 9-12.
We identified a PARK 2 (AR-JP) family with a patient presenting with homozygous deletion of D 6 S305--a marker within the 17cM region for PARK 2 locus. Markers surrounding D 6 S305 which are mapped 0 cM apart from D 6 S305, were not deleted, indicating that PARK 2 gene is located extremely close to D 6 S305. Exon search in the inserts with average size of 100 kb of BAC clones, which harbor D 6 S305, led us to find the exonic sequences which was subsequently proved to be exon 7 of the Parkin gene. From this exon sequences, full-length cDNA was isolated, and BAC contig covering Parkin gene was generated. Homozygous deletions or frame-shift mutations in the Parkin gene were found in the patients with AR-JP/PARK 2, revealing that a loss-of-function of Parkin gene is responsible for AR-JP/PARK 2. Our findings indicate that constant production of Parkin protein is essentially required for maintaining the survival of nigral neurons. One attractive hypothesis is that Parkinson's disease and AR-JP/PARK 2 might share a common effector pathway for nigral neuronal death. In this scenario, as PARK 2 is not accompanied with Lewy body formation. Parkin might act at or downstream of synuclein aggregation, which has been recently implicated as a trigger event for neuronal death in Parkinson's disease. In any case, identification of functional targets of Parkin protein will give us an important clue to identify downstream events of neuronal death which is activated by inclusion body formation.
Markopoulou, K., Z. K. Wszolek, et al. (1999). "Reduced expression of the G209A alpha-synuclein allele in familial Parkinsonism." Ann Neurol46(3): 374-81.
Missense mutations at the alpha-synuclein gene have been associated with familial parkinsonism. We report that the phenotype of a kindred (Family H) with autosomal dominant, levodopa-responsive parkinsonism maps to chromosomal region 4q21-23 and that affected members of this kindred harbor a previously reported mutation (G209A) in exon 4 of the alpha-synuclein gene. We assessed the expression of the G209A allele in lymphoblastoid cell lines established from 12 individuals heterozygous for the G209A allele. The expression of this allele is either absent or significantly reduced in 7 affected heterozygotes and in 3 asymptomatic heterozygotes who are older than the mean age at disease diagnosis for their generation. In contrast, it is expressed in 1 affected and 1 unaffected heterozygote. The unaffected heterozygote is younger than the mean age at disease diagnosis for their generation. The lack of or significantly reduced expression of the G209A allele in affected heterozygotes suggests that the timing of reduced expression may be critical for disease onset. If so, the parkinsonian phenotype may arise from haploinsufficiency at the alpha-synuclein gene at a time point before symptom onset. In conclusion, reduced alpha-synuclein gene expression may be important in the pathogenesis of parkinsonism.
Luedecking, E. K., M. Ganguli, et al. (1999). "Genetic polymorphism in the persyn (gamma-synuclein) gene and the risk of Alzheimer's disease." Neurosci Lett261(3): 186-8.
Alzheimer's disease (AD) is a complex disease with the possible involvement of several genes. Genetic studies on sporadic late-onset AD have determined APOE*4 to be the major risk factor. Members of the synuclein gene family are potential candidates for the risk of AD. The persyn gene (gamma-synuclein) has recently been characterized and a common polymorphism (Glu110Val) has been identified. In this study we investigated the association of this polymorphism with sporadic late-onset AD patients. We screened DNA samples of 313 late-onset cases and 352 controls. No significant association was observed between the missense mutation and AD. When the data were stratified by APOE*4 carriers and non-APOE*4 carriers, no difference was seen for the Glu110Val polymorphism. There was also no difference in genotype or allele frequency when stratified by the ACT*A allele. Although our data show no effect of this persyn polymorphism in AD, characterization of additional polymorphisms in this gene may provide more conclusive answers.
Lippa, C. F., M. L. Schmidt, et al. (1999). "Antibodies to alpha-synuclein detect Lewy bodies in many Down's syndrome brains with Alzheimer's disease." Ann Neurol45(3): 353-7.
Immunohistochemical examination of 20 Down's syndrome brains, using antibodies to alpha-, beta-, and gamma-synuclein, demonstrated many alpha-synuclein-positive Lewy bodies and dystrophic neurites in 50% of amygdala samples from Down's syndrome brains with Alzheimer's disease. Similar lesions were less common in other regions of these brains, none of which contained beta-synuclein or gamma-synuclein abnormalities. Thus, alpha-synuclein-positive Lewy bodies and neuritic processes frequently occur with Alzheimer's disease in Down's syndrome brains.
Lincoln, S., R. Crook, et al. (1999). "No pathogenic mutations in the beta-synuclein gene in Parkinson's disease." Neurosci Lett269(2): 107-9.
We present 11 families consistent with autosomal dominant inheritance of probable Parkinson's disease (PD). Although excluded as a cause of disease in these kindreds, mutations in the alpha-synuclein gene have been implicated in familial PD. The beta-synuclein gene is highly homologous, expressed in the nervous system and thus is a good candidate gene for PD. Multipoint linkage analysis was either equivocal or excluded 5q35 haplotype sharing among affected family members. Sequencing the translated exons of the beta-synuclein gene failed to identify any pathogenic mutation.
Lincoln, S., K. Gwinn-Hardy, et al. (1999). "No pathogenic mutations in the persyn gene in Parkinson's disease." Neurosci Lett259(1): 65-6.
The persyn (gamma-synuclein) gene is highly homologous to the alpha-synuclein gene and is highly expressed in the nervous system. It is therefore, an excellent candidate gene for Parkinson's disease. However, we have sequenced the gene in a large number of families with parkinsonism and failed to find pathogenic mutations.
Lin, J. J., K. C. Yueh, et al. (1999). "Absence of G209A and G88C mutations in the alpha-synuclein gene of Parkinson's disease in a Chinese population." Eur Neurol42(4): 217-20.
A G209A mutation in the alpha-synuclein gene was recently discovered in a large Italian kindred and three unrelated Greek kindreds with autosomal dominant Parkinson's disease (PD). Subsequently, another mutation in the gene (G88C) was also identified in a German family with autosomal PD. These results indicate that the alpha-synuclein gene may have an important role in the pathogenesis of PD. This study was designed to screen the existence of both mutations of the alpha-synuclein gene among 100 Chinese patients with PD, including 80 with sporadic and 20 with familial PD. Results showed that none of our patients, both sporadic and familial PD, had either of the two mutations of this gene. We therefore conclude that although of great interest, these two mutations are not relevant for the pathogenesis of PD in a Han Chinese population.
Kruger, R., A. M. Vieira-Saecker, et al. (1999). "Increased susceptibility to sporadic Parkinson's disease by a certain combined alpha-synuclein/apolipoprotein E genotype." Ann Neurol45(5): 611-7.
Parkinson's disease (PD) is one of the most common neurodegenerative disorders affecting about 1% of Western populations older than age 50. The pathological hallmark of PD are Lewy bodies, that is, intracytoplasmic inclusion bodies in affected neurons of the substantia nigra. Recently, alpha-synuclein (alpha-SYN) has been identified as the main component of Lewy bodies in sporadic PD, suggesting involvement in neurodegeneration via protein accumulation. The partially overlapping pathology of PD and Alzheimer's disease, as well as striking structural similarities of alpha-SYN and apolipoprotein E, which is a major risk factor for late-onset Alzheimer's disease, prompted us to investigate the influence of different alpha-SYN and apolipoprotein E alleles for developing sporadic PD. We performed association studies in 193 German PD patients and 200 healthy control subjects matched for age, sex, and origin. A polymorphism in the promoter region of the alpha-SYN gene (NACP-Rep1) as well as of the closely linked DNA markers D4S1647 and D4S1628 revealed significant differences in the allelic distributions between PD patients and the control group. Furthermore, the Apo epsilon4 allele but not the Th1/E47 promoter polymorphism of the apolipoprotein E gene was significantly more frequent among early-onset PD patients (age at onset, <50 years) than in late-onset PD. Regarding the combination of the Apo epsilon4 allele and allele 1 of the alpha-SYN promoter polymorphism, a highly significant difference between the group of PD patients and control individuals has been found, suggesting interactions or combined actions of these proteins in the pathogenesis of sporadic PD. PD patients harboring this genotype have a 12.8-fold increased relative risk for developing PD during their lives.
Kosel, S., G. Hofhaus, et al. (1999). "Role of mitochondria in Parkinson disease." Biol Chem380(7-8): 865-70.
The cause of the selective degeneration of nigrostriatal neurons in Parkinson disease (PD) has remained largely unknown. Exceptions include rare missense mutations in the alpha-synuclein gene on chromosome 4, a potentially pathogenic mutation affecting the ubiquitin pathway, and mutations in the parkin gene on chromosome 6. However, unlike classical PD, the latter syndrome is not associated with the formation of typical Lewy bodies. In contrast, a biochemical defect of complex I of the mitochondrial respiratory chain has been described in a relatively large group of confirmed PD cases. Recent cybrid studies indicate that the complex I defect in PD has a genetic cause and that it may arise from mutations in the mitochondrial DNA. Sequence analysis of the mitochondrial genome supports the view that mitochondrial point mutations are involved in PD pathogenesis. However, although mitochondria function as regulators in several known forms of cell death, their exact involvement in PD has remained unresolved. This is of relevance because classical apoptosis does not appear to play a major role in the degeneration of the parkinsonian nigra.
Kosaka, K. (1999). "[Diffuse Lewy body disease]." Ryoikibetsu Shokogun Shirizu(27 Pt 2): 82-5.
Klein, C., P. Vieregge, et al. (1999). "Search for the PARK3 founder haplotype in a large cohort of patients with Parkinson's disease from northern Germany." Ann Hum Genet63 ( Pt 4): 285-91.
A founder haplotype on chromosome 2p for autosomal dominant Parkinson's disease (PD) has been postulated for two families of Northern European descent, and a new mutation in the alpha-synuclein gene (Ala30Pro) has been found in a German PD family. We evaluated 85 German PD patients and 85 ethnically matched controls for shared markers on chromosome 2p and for the new alpha-synuclein mutation. We found no evidence for linkage disequilibrium, suggesting that the putative founder mutation on chromosome 2p is not a common cause of PD in the local population. Furthermore, no patient carried the Ala30Pro change, supporting earlier findings that mutations in the alpha-synuclein gene are extremely rare.
Kholodilov, N. G., M. Neystat, et al. (1999). "Increased expression of rat synuclein in the substantia nigra pars compacta identified by mRNA differential display in a model of developmental target injury." J Neurochem73(6): 2586-99.
Human alpha-synuclein was identified on the basis of proteolytic fragments derived from senile plaques of Alzheimer's disease, and it is the locus of mutations in some familial forms of Parkinson's disease. Its normal function and whether it may play a direct role in neural degeneration remain unknown. To explore cellular responses to neural degeneration in the dopamine neurons of the substantia nigra, we have developed a rodent model of apoptotic death induced by developmental injury to their target, the striatum. We find by mRNA differential display that synuclein is up-regulated in this model, and thus it provides an opportunity to examine directly whether synuclein plays a role in the death of these neurons or, alternatively, in compensatory responses. Up-regulation of mRNA is associated with an increase in the number of neuronal profiles immunostained for synuclein protein. At a cellular level, synuclein is almost exclusively expressed in normal neurons, rather than apoptotic profiles. Synuclein is up-regulated throughout normal postnatal development of substantia nigra neurons, but it is not further up-regulated during periods of natural cell death. We conclude that up-regulation of synuclein in the target injury model is unlikely to mediate apoptotic death and propose that it may be due to a compensatory response in neurons destined to survive.
Kholodilov, N. G., T. F. Oo, et al. (1999). "Synuclein expression is decreased in rat substantia nigra following induction of apoptosis by intrastriatal 6-hydroxydopamine." Neurosci Lett275(2): 105-8.
We have previously shown that synuclein is upregulated in the substantia nigra following developmental lesion of the target striatum. In this model, synuclein is preferentially expressed in normal-appearing neurons, rather than those which undergo apoptosis. It has been proposed, however, that synuclein may mediate apoptosis in other contexts, such as that induced by neurotoxins. To examine this possibility, we have studied a model in which apoptosis is induced in dopamine neurons by intrastriatal injection of 6-hydroxydopamine. In this model synuclein mRNA and protein expression are not upregulated at any time point, but instead diminish as dopamine neurons die. We observe a complete dissociation between apoptotic morphology and synuclein protein expression. We conclude that synuclein is unlikely to play a direct role in apoptotic death in dopamine neurons and is more likely, in the target injury model, to play a role in protection or restoration of neurons which survive.
Jia, T., Y. E. Liu, et al. (1999). "Stimulation of breast cancer invasion and metastasis by synuclein gamma." Cancer Res59(3): 742-7.
We recently identified and cloned novel breast cancer-specific gene BCSG1 by direct differential cDNA sequencing. BCSG1 has a great sequence homology with the Alzheimer's disease related neural protein synuclein (SNC); thus, it was also named SNC-gamma. Overexpression of SNC-gamma in breast cancer cells leads to a significant increase in motility and invasiveness in vitro and a profound augmentation of metastasis in vivo. Our data suggest that this member of the neural protein SNCs might have important functions outside the central nervous system and may play a role in breast cancer progression.
Jensen, P. H., J. Y. Li, et al. (1999). "Axonal transport of synucleins is mediated by all rate components." Eur J Neurosci11(10): 3369-76.
Synucleins are abundant nerve terminal proteins of hitherto unknown function. In diseases with Lewy bodies, human alpha-synuclein concentrates in these lesions in the cell body and mutations in alpha-synuclein lead to heritable Parkinson's disease with Lewy bodies. This indicates that changes in the normal metabolism and axonal transport of alpha-synuclein is perturbed in these diseases. To investigate the normal axonal transport of synucleins we studied the rat visual system by nerve crush operations and metabolic labelling of the retinal ganglion cells followed by immunoprecipitation of nerve segments. We found by immunofluorescence microscopy of the crush-operated nerves that synucleins are transported by fast antero- and retrograde transport and colocalize with synaptophysin and SNAP-25 around the lesion. The metabolic labelling studies demonstrated that synucleins were moved through the nerve with all the rate components, the fast component and the slow components a and b, with component b predominating. Two-dimensional gel electrophoresis revealed that both alpha- and beta-synuclein migrate through the nerve by slow component b in a ratio of 2:1.
Jensen, P. H., H. Hager, et al. (1999). "alpha-synuclein binds to Tau and stimulates the protein kinase A-catalyzed tau phosphorylation of serine residues 262 and 356." J Biol Chem274(36): 25481-9.
alpha-Synuclein has been implicated in the pathogenesis of several neurodegenerative disorders based on the direct linking of missense mutations in alpha-synuclein to autosomal dominant Parkinson's disease and its presence in Lewy-like lesions. To gain insight into alpha-synuclein functions, we have investigated whether it binds neuronal proteins and modulates their functional state. The microtubule-associated protein tau was identified as a ligand by alpha-synuclein affinity chromatography of human brain cytosol. Direct binding assays using (125)I-labeled human tau40 demonstrated a reversible binding with a IC(50) about 50 pM. The interacting domains were localized to the C terminus of alpha-synuclein and the microtubule binding region of tau as determined by protein fragmentation and the use of recombinant peptides. High concentrations of tubulin inhibited the binding between tau and alpha-synuclein. Functionally, alpha-synuclein stimulated the protein kinase A-catalyzed phosphorylation of tau serine residues 262 and 356 as determined using a phospho-epitope-specific antibody. We propose that alpha-synuclein modulates the phosphorylation of soluble axonal tau and thereby indirectly affects the stability of axonal microtubules.
Jarman, P. and N. Wood (1999). "Parkinson's disease genetics comes of age." Bmj318(7199): 1641-2.
Jakes, R., R. A. Crowther, et al. (1999). "Epitope mapping of LB509, a monoclonal antibody directed against human alpha-synuclein." Neurosci Lett269(1): 13-6.
Alpha-synuclein is a 140 amino acid protein that forms the major component of the abnormal filaments that make up the Lewy bodies and Lewy neurites of Parkinson's disease and dementia with Lewy bodies. It is also the major component of the filamentous glial cytoplasmic inclusions of multiple system atrophy. Here we have used recombinant alpha-synucleins and peptide competition to show that the monoclonal anti-alpha-synuclein antibody LB509 recognizes amino acids 115-122 of human alpha-synuclein. The antibody strongly labelled filaments extracted from multiple system atrophy brain, showing the presence of residues 115-122 of alpha-synuclein. LB509 failed to react with mouse, rat and zebra finch alpha-synuclein, because of amino acid differences with human alpha-synuclein. Since LB509 recognizes human but not rodent alpha-synuclein, it will be a useful reagent for the characterization of mouse lines transgenic for human alpha-synuclein.
Iwatsubo, T. (1999). "[Parkinson's disease, dementia with Lewy bodies, multiple system atrophy and alpha-synuclein]." Rinsho Shinkeigaku39(12): 1285-6.
Lewy bodies (LBs) are hallmark lesions of degenerating neurons in the brains of patients with Parkinson's disease (PD) and dementia with Lewy bodies (DLB). DLB is the second most common neurodegenerative dementia after Alzheimer's disease, which is characterized clinically by fluctuating cognitive impairments, visual hallucinations and parkinsonism, and pathologically by the appearance of cortical LBs. To characterize the components of LBs, we have developed a purification procedure for LBs from cortices of patients with DLB using sucrose density separation followed by fluorescence-activated particle sorting. We then raised monoclonal antibodies (mAbs) to purified LBs, and obtained a mAb (LB509) that intensely immunolabeled LBs and specifically reacted with a approximately 18kDa brain protein, which was identified as alpha-synuclein. LB509 as well as other antibodies to alpha-synuclein, but not to beta-synuclein, immunostained brainstem and cortical LBs in sporadic PD and DLB brains. Recently, a point mutation in alpha-synuclein gene was identified in some autosomal-deminantly inherited familial PD pedigrees. Moreover, glial cytoplasmic inclusions in the brains of patients with multiple system atrophy (MSA) were shown to be alpha-synuclein positive. Taken together, our data strongly implicate alpha-synuclein in the formation of LBs and the selective neuronal degeneration in PD, DLB and MSA.
Iwatsubo, T. (1999). "[alpha-Synuclein and familial Parkinson's disease]." No To Shinkei51(6): 481-6.
Iwanaga, K., K. Wakabayashi, et al. (1999). "Lewy body-type degeneration in cardiac plexus in Parkinson's and incidental Lewy body diseases." Neurology52(6): 1269-71.
Heart tissues of patients with PD or incidental Lewy body (LB) disease (ILBD) were examined by light and electron microscopy. LBs and alpha-synuclein-positive neurites were identified in the hearts from 9 of 11 patients with PD and from 7 of 7 patients with ILBD. LBs were present in both tyrosine hydroxylase-positive and -negative nerve processes, which are nerves of extrinsic sympathetic and intrinsic origin, respectively. These findings provide histologic evidence that the postganglionic sympathetic and intrinsic neurons in the heart are involved in the PD disease process.
Iseki, E., W. Marui, et al. (1999). "Frequent coexistence of Lewy bodies and neurofibrillary tangles in the same neurons of patients with diffuse Lewy body disease." Neurosci Lett265(1): 9-12.
We examined the frequency of neurons with coexistent Lewy bodies (LB) and neurofibrillary tangles (NFT) in diffuse Lewy body disease brains, by a double-immunostaining method using MDV2 and Human tau. Double-positive neurons were frequently observed in the limbic areas. These neurons mostly revealed the feature of intermingled MDV2- and Human tau-positive substances. Immunoelectron microscopically, the MDV2-positive components were not in continuity with the MDV2-negative paired helical filaments (PHF). The MDV2-positive LB were surrounded by the small PHF bundles, frequently accompanied by the randomly oriented PHF within LB. In the intermingled neurons, MDV2-positive non-filamentous components without LB were found among the large PHF bundles. These non-filamentous components may represent the early stage of LB formation.
Hu, C. J., S. M. Sung, et al. (1999). "No mutation of G209A in the alpha-synuclein gene in sporadic Parkinson's disease among Taiwan Chinese." Eur Neurol41(2): 85-7.
The role of genetics in Parkinson's disease (PD), previously controversial, is now supported by several studies. A major breakthrough has been the discovery of a single gene defect in familial Parkinson's disease. A single base pair change at position 209 from G to A (G209A) in the fourth exon of the alpha-synuclein gene has been identified in cases of familial PD. We looked for this mutation in 65 cases of sporadic PD in Taiwan Chinese patients but found none of these patients with this mutation. We conclude that mutation of G209A in the alpha-synuclein gene plays no role in sporadic PD among Taiwan Chinese.
Hellstrom, J., U. Arvidsson, et al. (1999). "Differential expression of nerve terminal protein isoforms in VAChT-containing varicosities of the spinal cord ventral horn." J Comp Neurol411(4): 578-90.
Of the different types of synaptic contacts with the mammalian spinal motoneuron, the synapse made by the cholinergic, so-called C-terminal of unknown origin and function has special morphological characteristics. Thus, in this synapse, there is no postsynaptic density but rather a large subsynaptic cistern in the motoneuron. To see whether this particular arrangement imposes special demands on the transmitter release machinery, we examined the presence of nerve terminal proteins in the C-terminal by using immunohistochemistry. Cholinergic nerve fibers and terminals in the spinal cord ventral horn were identified with an antiserum to the vesicular acetylcholine transporter (VAChT) protein. Immunohistochemistry in combination with confocal laser microscopy showed the presence of synaptosomal-associated protein of 25 kDa (SNAP-25)-, syntaxin-, cysteine string protein (CSP)-, synuclein-, synapsin I-, synapsin I/II-, synaptotagmin I-, synaptotagmin I/II-, synaptophysin-, and synaptobrevin-2-like immunoreactivity (-LI) in VAChT-containing C-terminals. Synaptotagmin III and synaptobrevin 1 could not be demonstrated in this type of terminal. VAChT-containing varicosities in the Renshaw cell area, with a probable origin from motoneuron axon collaterals, exhibited CSP, synapsin I/II, and synaptobrevin-1-LI, but not SNAP-25-, syntaxin-, synuclein-, synapsin I-, synaptotagmin I-, synaptotagmin I/II-, synaptophysin- and synaptobrevin-2-LI. The results suggest a differential content of nerve terminal proteins and their isoforms in cholinergic C-terminals apposing motoneurons and in the Renshaw cell area. It is concluded that C-terminals contain synaptic proteins necessary for fast transmitter release, and their origin should not be the motoneurons themselves.
Hattori, N., S. Sumino, et al. (1999). "[An 80-year-old woman with parkinsonism and progressive dementia]." No To Shinkei51(6): 541-50.
We report an 80-year-old Japanese woman who presented levodopa-responsible parkinsonism followed by progressive dementia. She was well until her 61 years of age (in 1978) when she noted onset of resting tremor in her right hand followed by tremor in her right leg. She was treated with levodopa and trihexyphenidyl with good response, however, later on, she suffered from gait disturbance. In 1985, she had an episode of cardio-pulmonary arrest from which she was resuscitated, however, she started to show hypermetamorphosis, memory defect, and aggressive behaviors. She also developed motor fluctuations and dyskinesias from levodopa. She was admitted to our service in 1986; she showed rather typical parkinsonism and mild dementia. She received left Vim thalamotomy in the same year. Her dyskinesias improved, however, her gait disturbance became progressively worse. In 1995, she was admitted to our service again; she showed marked dementia and advanced parkinsonism; she was unable to walk unsupported. She became bedridden in 1996 and gastrostomy was placed. She was transferred to Zushi Aoki Hospital. Her dementia became progressively worse, and she was in the akinetic and mute state. She expired on April 22, 1998. She was discussed in a neurological CPC. The chief discussant arrived at a conclusion that the patient had Parkinson's disease with complication by Alzheimer's disease in her later clinical course. The diagnoses of participants were divided among Parkinson's disease with dementia, Parkinson's disease and Alzheimer's disease, and diffuse Lewy body disease. Postmortem examination revealed marked neuronal loss in the substantia nigra and the locus coeruleus. Lewy bodies were found in the substantia nigra. In addition, rather many Lewy bodies of cortical type were seen in the cingulate gylus, inferior temporal gylus, and in the amygdaloid nucleus. These Lewy bodies were positive for alpha-synuclein. Also, tau-positive intra-neuronal tangles were seen in the hippocampus and in the substantia nigra. The Meynert nucleus showed marked neuronal loss. Pathologic findings were consistent with the diagnosis of diffuse Lewy body disease.
Hashimoto, M. and E. Masliah (1999). "Alpha-synuclein in Lewy body disease and Alzheimer's disease." Brain Pathol9(4): 707-20.
Alzheimer's disease (AD) and Lewy body disease (LBD) are the most common causes of dementia in the elderly population. Previous studies have shown that cognitive alterations in these disorders are associated with synaptic loss. Injury and loss of synapses might be associated with altered function of synaptic proteins. Among them, recent studies have shown that abnormal aggregation and accumulation of synaptic proteins, such as alpha-synuclein, might be associated with plaque formation in AD and Lewy body formation in LBD. Further reinforcing the hypothesis that alpha-synuclein plays a major role in the pathogenesis of these disorders, recent work has shown that mutations that alter the conformation of this molecule are associated with familial forms of Parkinson's disease. The mechanisms by which altered function or aggregation of alpha-synuclein might lead to neurodegeneration are not completely clear; however, new evidence points to a potential role for this molecule in synaptic damage and neurotoxicity via amyloid-like fibril formation and mitochondrial dysfunction. In this manuscript we review the data linking alpha-synuclein to the pathogenesis of AD and LBD.
Hashimoto, M., A. Takeda, et al. (1999). "Role of cytochrome c as a stimulator of alpha-synuclein aggregation in Lewy body disease." J Biol Chem274(41): 28849-52.
alpha-Synuclein is a major component of aggregates forming amyloid-like fibrils in diseases with Lewy bodies and other neurodegenerative disorders, yet the mechanism by which alpha-synuclein is intracellularly aggregated during neurodegeneration is poorly understood. Recent studies suggest that oxidative stress reactions might contribute to abnormal aggregation of this molecule. In this context, the main objective of the present study was to determine the potential role of the heme protein cytochrome c in alpha-synuclein aggregation. When recombinant alpha-synuclein was coincubated with cytochrome c/hydrogen peroxide, alpha-synuclein was concomitantly induced to be aggregated. This process was blocked by antioxidant agents such as N-acetyl-L-cysteine. Hemin/hydrogen peroxide similarly induced aggregation of alpha-synuclein, and both cytochrome c/hydrogen peroxide- and hemin/hydrogen peroxide-induced aggregation of alpha-synuclein was partially inhibited by treatment with iron chelator deferoxisamine. This indicates that iron-catalyzed oxidative reaction mediated by cytochrome c/hydrogen peroxide might be critically involved in promoting alpha-synuclein aggregation. Furthermore, double labeling studies for cytochrome c/alpha-synuclein showed that they were colocalized in Lewy bodies of patients with Parkinson's disease. Taken together, these results suggest that cytochrome c, a well known electron transfer, and mediator of apoptotic cell death may be involved in the oxidative stress-induced aggregation of alpha-synuclein in Parkinson's disease and related disorders.
Hashimoto, M., L. J. Hsu, et al. (1999). "Oxidative stress induces amyloid-like aggregate formation of NACP/alpha-synuclein in vitro." Neuroreport10(4): 717-21.
The precursor of non-amyloid beta protein component of Alzheimer's disease amyloid (NACP/alpha-synuclein), found in Lewy bodies of Parkinson's disease (PD), is a presynaptic protein genetically linked to some familial types PD. Mechanisms of abnormal NACP/alpha-synuclein aggregation in neurodegenerative diseases are unclear. Since oxidative stress might play a role in PD pathogenesis, we investigated the role of iron and peroxide in NACP/alpha-synuclein aggregation. Immunoblot analysis showed that human NACP/alpha-synuclein (but not beta-synuclein) aggregated in the presence of ferric ion and was inhibited by the iron chelator deferoxamine. Ferrous ion was not effective by itself, but it potentially aggregated NACP/alpha-synuclein in the presence of hydrogen peroxide. NACP/ alpha-synuclein aggregates displayed strong thioflavine-S and congo-red reactivity, reminiscent of amyloid. This study suggests that NACP/alpha-synuclein aggregation might be closely related to oxidative reactions which may play a critical role in neurodegeneration in disorders with Lewy bodies.
Hardy, J. and K. Gwinn-Hardy (1999). "Neurodegenerative disease: a different view of diagnosis." Mol Med Today5(12): 514-7.
Neurodegenerative diseases have traditionally been defined as clinicopathological entities. Although this has been a productive paradigm in terms of the development of treatment strategies, molecular genetic approaches have revealed that there is overlap between different entities in pathogenic mechanisms. In this article, it is argued that neurodegenerative disease should also be thought of as the consequences of sequential biochemical processes, and that some parts of these processes appear to operate in more than one disease entity. Defining these pathways and, in particular, developing an appreciation of the commonalities between different diseases, should aid in the development of therapies that are effective in several diseases.
Gomez-Tortosa, E., K. Newell, et al. (1999). "Clinical and quantitative pathologic correlates of dementia with Lewy bodies." Neurology53(6): 1284-91.
OBJECTIVES: To examine the distribution of cortical Lewy bodies (LB) and their contribution to the clinical syndrome in dementia with LB (DLB) and to address their relationship to the pathologic markers of AD and PD. METHODS: We studied 25 cases meeting neuropathologic criteria for DLB: 13 cases without AD (Braak stage I or II) and 12 cases with concomitant AD changes (Braak stages III to V). Age at onset, disease duration, and clinical symptoms were reviewed for each case. We quantified the regional distribution of LB in substantia nigra, paralimbic areas (cingulate gyrus, insula, entorhinal cortex, and hippocampus), and neocortex (frontal and occipital association areas) using anti-alpha-synuclein immunostaining. We compared the LB pathology between groups of patients with different symptoms at onset or with specific clinical phenotypes. RESULTS: There were no significant differences in clinical symptoms or LB density between cases with or without concomitant AD. LB density showed a consistent gradient as follows: substantia nigra > entorhinal cortex > cingulate gyrus > insula > frontal cortex > hippocampus > occipital cortex. LB density in substantia nigra and neocortex was not significantly different in cases that started with parkinsonism compared with those that started with dementia. There were no significant differences in LB density in any region among patients with or without cognitive fluctuations, visual hallucinations, delusions, recurrent falls, or parkinsonism. Duration of the disease correlated with a global LB burden for each case (p = 0.02) but did not correlate with LB density in any individual area. Paralimbic and neocortical LB density were highly correlated with each other (p<0.0001), but neither of these correlated well with the number of LB in substantia nigra. LB density did not correlate with Braak stage or frequency of neuritic plaques. CONCLUSIONS: There is a consistent pattern of vulnerability to LB formation across subcortical, paralimbic, and neocortical structures that is similar for DLB cases with or without concomitant AD. Paralimbic and neocortical LB do not correlate with LB in substantia nigra, suggesting that DLB should not be considered just a severe form of PD. LB density correlates weakly with clinical symptoms and disease duration.
Golbe, L. I. (1999). "Alpha-synuclein and Parkinson's disease." Mov Disord14(1): 6-9.
Goedert, M. (1999). "Filamentous nerve cell inclusions in neurodegenerative diseases: tauopathies and alpha-synucleinopathies." Philos Trans R Soc Lond B Biol Sci354(1386): 1101-18.
Alzheimer's disease and Parkinson's disease are the most common neurodegenerative diseases. They are characterized by the degeneration of selected populations of nerve cells that develop filamentous inclusions before degeneration. The neuronal inclusions of Alzheimer's disease are made of the microtubule-associated protein tau, in a hyperphosphorylated state. Recent work has shown that the filamentous inclusions of Parkinson's disease are made of the protein alpha-synuclein and that rare, familial forms of Parkinson's disease are caused by missense mutations in the alpha-synuclein gene. Besides Parkinson's disease, the filamentous inclusions of two additional neurodegenerative diseases, namely dementia with Lewy bodies and multiple system atrophy, have also been found to be made of alpha-synuclein. Abundant filamentous tau inclusions are not limited to Alzheimer's disease. They are the defining neuropathological characteristic of frontotemporal dementias such as Pick's disease, and of progressive supranuclear palsy and corticobasal degeneration. The recent discovery of mutations in the tau gene in familial forms of frontotemporal dementia has provided a direct link between tau dysfunction and dementing disease. The new work has established that tauopathies and alpha-synucleinopathies account for most late-onset neurodegenerative diseases in man. The formation of intracellular filamentous inclusions might be the gain of toxic function that leads to the demise of affected brain cells.
Giasson, B. I., K. Uryu, et al. (1999). "Mutant and wild type human alpha-synucleins assemble into elongated filaments with distinct morphologies in vitro." J Biol Chem274(12): 7619-22.
alpha-Synuclein is a soluble presynaptic protein which is pathologically redistributed within intracellular lesions characteristic of several neurodegenerative diseases. Here we demonstrate that wild type and two mutant forms of alpha-synuclein linked to familial Parkinson's disease (Ala30 --> Pro and Ala53 --> Thr) self-aggregate and assemble into 10-19-nm-wide filaments with distinct morphologies under defined in vitro conditions. Immunogold labeling demonstrates that the central region of all these filaments are more robustly labeled than the N-terminal or C-terminal regions, suggesting that the latter regions are buried within the filaments. Since in vitro generated alpha-synuclein filaments resemble the major ultrastructural elements of authentic Lewy bodies that are hallmark lesions of Parkinson's disease, we propose that self-aggregating alpha-synuclein is the major subunit protein of these filamentous lesions.
Galvin, J. E., K. Uryu, et al. (1999). "Axon pathology in Parkinson's disease and Lewy body dementia hippocampus contains alpha-, beta-, and gamma-synuclein." Proc Natl Acad Sci U S A96(23): 13450-5.
Pathogenic alpha-synuclein (alphaS) gene mutations occur in rare familial Parkinson's disease (PD) kindreds, and wild-type alphaS is a major component of Lewy bodies (LBs) in sporadic PD, dementia with LBs (DLB), and the LB variant of Alzheimer's disease, but beta-synuclein (betaS) and gamma-synuclein (gammaS) have not yet been implicated in neurological disorders. Here we show that in PD and DLB, but not normal brains, antibodies to alphaS and betaS reveal novel presynaptic axon terminal pathology in the hippocampal dentate, hilar, and CA2/3 regions, whereas antibodies to gammaS detect previously unrecognized axonal spheroid-like lesions in the hippocampal dentate molecular layer. The aggregation of other synaptic proteins and synaptic vesicle-like structures in the alphaS- and betaS-labeled hilar dystrophic neurites suggests that synaptic dysfunction may result from these lesions. Our findings broaden the concept of neurodegenerative "synucleinopathies" by implicating betaS and gammaS, in addition to alphaS, in the onset/progression of PD and DLB.
Gai, W. P., J. H. Power, et al. (1999). "Alpha-synuclein immunoisolation of glial inclusions from multiple system atrophy brain tissue reveals multiprotein components." J Neurochem73(5): 2093-100.
Immunohistochemical studies have shown that oligodendroglial inclusions in multiple system atrophy contain alpha-synuclein, a synaptic protein also found in Lewy bodies in Parkinson's disease. We have now used density gradient enrichment and an anti-alpha-synuclein immunomagnetic technique to isolate pure and morphologically intact oligodendroglial inclusions from brain white matter of patients dying with multiple system atrophy. Filamentous inclusion structures were obtained only from multiple system atrophy tissue, but not from normal brain tissues, or from multiple system atrophy tissue processed without anti-alpha-synuclein antibody. We confirmed the purity and morphology of isolated inclusions by electron microscopy. The inclusions comprised multiple protein bands after separation by polyacrylamide gel electrophoresis. Immunoblotting demonstrated that these proteins included alpha-synuclein, alphaB-crystallin, tubulins, ubiquitin, and prominent, possibly truncated alpha-synuclein species as high-molecular-weight aggregates. Our study provides the first biochemical evidence that oligodendroglial inclusion filaments consist of multiple protein components, suggesting that these inclusions may form as a result of multiprotein interactions with alpha-synuclein.
Flowers, J. M., P. N. Leigh, et al. (1999). "Mutations in the gene encoding human persyn are not associated with amyotrophic lateral sclerosis or familial Parkinson's disease." Neurosci Lett274(1): 21-4.
The synucleins are a family of small proteins expressed in nervous tissue, which have been implicated in neurodegeneration. Using single strand conformation polymorphism analysis we screened for polymorphisms and mutations in the gene encoding human persyn, a recently discovered member of the synuclein family, in controls, patients with sporadic or familial amyotrophic lateral sclerosis (ALS) or familial Parkinson's disease (PD). Six polymorphisms in the genomic sequence of persyn were detected; A590C (5' untranslated region), G1943C (exon 3), G2049A (intron 3), T4502C (intron 3), T4552A (exon 4) and C5019T (3' untranslated region). However no associations with disease state were found in our sample group.
Farrer, M., K. Gwinn-Hardy, et al. (1999). "The genetics of disorders with synuclein pathology and parkinsonism." Hum Mol Genet8(10): 1901-5.
Despite being considered the archetypal non-genetic neurological disorder, genetic analysis of Parkinson's disease has shown that there are at least three genetic loci. Furthermore, these analyses have suggested that the phenotype of the pathogenic loci is wider than simple Parkinson's disease and may include Lewy body dementia and some forms of essential tremor. Identification of alpha-synuclein as the first of the loci involved in Parkinson's disease and the identification of this protein in pathological deposits in other disorders has led to the suggestion that it may share pathogenic mechanisms with multiple system atrophy, Alzheimer's disease and prion disease and that these mechanisms are related to a synuclein pathway to cell death. Finally, genetic analysis of the synuclein diseases and the tau diseases may indicate that this synuclein pathway is an alternative to the tau pathway to cell death.
Engelender, S., Z. Kaminsky, et al. (1999). "Synphilin-1 associates with alpha-synuclein and promotes the formation of cytosolic inclusions." Nat Genet22(1): 110-4.
Parkinson disease (PD) is a neurodegenerative disease characterized by tremor, bradykinesia, rigidity and postural instability. Post-mortem examination shows loss of neurons and Lewy bodies, which are cytoplasmic eosinophilic inclusions, in the substantia nigra and other brain regions. A few families have PD caused by mutations (A53T or A30P) in the gene SNCA (encoding alpha-synuclein). Alpha-synuclein is present in Lewy bodies of patients with sporadic PD, suggesting that alpha-synuclein may be involved in the pathogenesis of PD. It is unknown how alpha-synuclein contributes to the cellular and biochemical mechanisms of PD, and its normal functions and biochemical properties are poorly understood. To determine the protein-interaction partners of alpha-synuclein, we performed a yeast two-hybrid screen. We identified a novel interacting protein, which we term synphilin-1 (encoded by the gene SNCAIP). We found that alpha-synuclein interacts in vivo with synphilin-1 in neurons. Co-transfection of both proteins (but not control proteins) in HEK 293 cells yields cytoplasmic eosinophilic inclusions.
Duyckaerts, C., M. A. Colle, et al. (1999). "[Alzheimer's disease: lesions and their progression]." Rev Neurol (Paris)155 Suppl 4: S17-27.
Alzheimer disease appears to be a stereotyped mode of reaction of the central nervous system to various types of aggression such as different mutations involving various proteins, trisomy 21 or repeated head trauma as in dementia pugilistica. Rather than a disease, it appears to be a clinicopathological syndrome due to various causes. Lesions may be considered under 3 headings: neurofibrillary pathology, A beta peptide deposits and loss (neuronal and synaptic). Neurofibrillary pathology includes the neurofibrillary tangle, the crown of the senile plaque and the neuropil threads. All those lesions are characterized by the same ultrastructure--i.e. the accumulation of paired helical filaments--and the same immunohistochemistry: they are labelled by antibodies directed against the tau proteins. The amyloid deposits, present in the core of the senile plaque and in the vascular walls, are made of a 40 to 42 amino-acids long peptide, named A beta, derived from the amyloid precursor protein (APP). Antibodies directed against the A beta peptide also label diffuse deposits that are devoid of the tinctorial affinities and of the biochemical properties of amyloid substances. Those diffuse deposits are insufficient to cause dementia since they may be observed in high density in aged people without intellectual deterioration. Neuronal loss occurs after neurofibrillary pathology. The role of the synaptic pathology remains discussed. Besides tau proteins, A beta peptide and APP, several other proteins may play an important role: apolipoprotein E which could act as a chaperone protein, inducing or facilitating the formation of amyloid, presenilins 1 and 2, mutated in some cases of familial Alzheimer disease, alpha-synuclein which is present in the Lewy bodies found in Parkinson disease and in dementia with Lewy bodies. The A beta deposits are diffusely distributed in the cerebral cortex; the neurofibrillary changes have a hierarchical distribution. The progression of the neurofibrillary pathology in the various cortical areas follow a stereotyped sequence that may help to grade the severity of the disease. Progression may take decades. The relations between aging and Alzheimer disease are still poorly understood. Frequency of Alzheimer type lesions in old people could suggest that they are the inevitable burden of age, but this has been discussed.
Duda, J. E., U. Shah, et al. (1999). "The expression of alpha-, beta-, and gamma-synucleins in olfactory mucosa from patients with and without neurodegenerative diseases." Exp Neurol160(2): 515-22.
A family of homologous proteins known as alpha-, beta-, and gamma-synuclein are abundantly expressed in brain, especially in the presynaptic terminal of neurons. Although the precise function of these proteins remains unknown, alpha-synuclein has been implicated in synaptic plasticity associated with avian song learning as well as in the pathogenesis of Parkinson's disease (PD), dementia with LBs (DLB), some forms of Alzheimer's disease (AD), and multiple system atrophy (MSA). Since olfactory dysfunction is a common feature of these disorders and the olfactory receptor neurons (ORNs) of the olfactory epithelium (OE) regenerate throughout the lifespan, we used antibodies specific for alpha-, beta-, and gamma-synucleins to examine the olfactory mucosa of patients with PD, DLB, AD, MSA, and controls without a neurological disorder. Although antibodies to alpha- and beta-synucleins detected abnormal dystrophic neurites in the OE of patients with neurodegenerative disorders, similar pathology was also seen in the OE of controls. More significantly, we show here for the first time that alpha-, beta-, and gamma-synucleins are differentially expressed in cells of the OE and respiratory epithelium and that alpha-synuclein is the most abundant synuclein in the olfactory mucosa, where it is prominently expressed in ORNs. Moreover, alpha- and gamma-synucleins also were prominent in the OE basal cells, which include the progenitor cells of the ORNs in the OE. Thus, our data on synuclein expression within the OE may signify that synuclein plays a role in the regeneration and plasticity of ORNs in the adult human OE.
Dickson, D. W., W. Lin, et al. (1999). "Multiple system atrophy: a sporadic synucleinopathy." Brain Pathol9(4): 721-32.
Multiple system atrophy (MSA) is a sporadic neurodegenerative disease characterized clinically by varying degrees of Parkinsonism, cerebellar ataxia and autonomic dysfunction and pathologically by degeneration in the substantia nigra, putamen, olivary nucleus, pontine nuclei and cerebellum. In addition to selective neuronal loss, iron pigment accumulation and gliosis, myelin pathology is increasingly recognized. In affected white matter, myelin displays signs of degeneration and oligodendroglia contain argyrophilic inclusion bodies, so-called glial cytoplasmic inclusions (GCI). GCI are composed of 10-15-nm diameter coated filaments that are immunoreactive for ubiquitin and alpha-synuclein. Similar inclusions are occasionally found in neuronal cell bodies and cell processes in MSA. Given the presence of inclusion bodies composed of synuclein, it is reasonable to assume that biochemical alterations would be detected in synuclein in MSA and indeed this is the case. In MSA synuclein has biophysical properties that suggest increasing insolubility such as sedimentation in dense fractions in sucrose gradients and ready extraction into detergents and formic acid. Surprisingly, these biochemical modifications in synuclein are more widespread in the brain that the obvious pathology and suggest a fundamental molecular characteristic of the disorder. Similar neuronal, and less frequently glial, inclusions are detected in Lewy body disease, where there is also evidence for biophysical alterations in synuclein. Thus, MSA and LBD are both synucleinopathies, and they may comprise different poles of a disease spectrum that includes sporadic disorders as well as genetically determined disorders such as familial Lewy body Parkinsonism.
Dickson, D. W. (1999). "Tau and synuclein and their role in neuropathology." Brain Pathol9(4): 657-61.
Dickson, D. W., W. Liu, et al. (1999). "Widespread alterations of alpha-synuclein in multiple system atrophy." Am J Pathol155(4): 1241-51.
Glial cytoplasmic inclusions (GCI) are the hallmark of multiple system atrophy (MSA), a rare movement disorder frequently associated with autonomic dysfunction. In this study of 21 cases of MSA, GCI were consistently immunoreactive for alpha-synuclein and double-immunostained for ubiquitin and oligodendroglial markers, but not glial fibrillary acidic protein. No statistically significant difference was found in the density of GCI in various brain regions in the two forms of MSA, striatonigral degeneration (SND) and olivopontocerebellar atrophy (OPCA). Postmortem brain samples from 9 cases of MSA were fractionated according to solubility in buffer, Triton-X 100, sodium dodecyl sulfate (SDS), and formic acid, and alpha-synuclein immunoreactivity was measured in Western blots. Total alpha-synuclein immunoreactivity was increased in MSA compared to controls, with no statistically significant difference between SND and OPCA. Most of the increase was due to alpha-synuclein in SDS fractions. In controls this fraction had little or no immunoreactivity. In 7 cases and 4 controls correlations were investigated between quantitative neuropathology and biochemical properties of alpha-synuclein. Surprisingly, the amount of SDS-soluble alpha-synuclein correlated poorly with the number of GCI in adjacent sections. Furthermore, areas with few or no GCI unexpectedly had abundant SDS-soluble alpha-synuclein. These findings provide evidence that modifications of alpha-synuclein in MSA may be more widespread than obvious histopathology. Moreover, these alterations may constitute a biochemical signature for the synucleinopathies.
Culvenor, J. G., C. A. McLean, et al. (1999). "Non-Abeta component of Alzheimer's disease amyloid (NAC) revisited. NAC and alpha-synuclein are not associated with Abeta amyloid." Am J Pathol155(4): 1173-81.
alpha-Synuclein (alphaSN), also termed the precursor of the non-Abeta component of Alzheimer's disease (AD) amyloid (NACP), is a major component of Lewy bodies and Lewy neurites pathognomonic of Parkinson's disease (PD) and dementia with Lewy bodies (DLB). A fragment of alphaSN termed the non-Abeta component of AD amyloid (NAC) had previously been identified as a constituent of AD amyloid plaques. To clarify the relationship of NAC and alphaSN with Abeta plaques, antibodies were raised to three domains of alphaSN. All antibodies produced punctate labeling of human cortex and strong labeling of Lewy bodies. Using antibodies to alphaSN(75-91) to label cortical and hippocampal sections of pathologically proven AD cases, we found no evidence for NAC in Abeta amyloid plaques. Double labeling of tissue sections in mixed DLB/AD cases revealed alphaSN in dystrophic neuritic processes, some of which were in close association with Abeta plaques restricted to the CA1 hippocampal region. In brain homogenates alphaSN was predominantly recovered in the cytosolic fraction as a 16-kd protein on Western analysis; however, significant amounts of aggregated and alphaSN fragments were also found in urea extracts of SDS-insoluble material from DLB and PD cases. NAC antibodies identified an endogenous fragment of 6 kd in the cytosolic and urea-soluble brain fractions. This fragment may be produced as a consequence of alphaSN aggregation or alternatively may accelerate aggregation of the full-length alphaSN.
Clayton, D. F. and J. M. George (1999). "Synucleins in synaptic plasticity and neurodegenerative disorders." J Neurosci Res58(1): 120-9.
Synucleins are small highly conserved proteins in vertebrates, especially abundant in neurons and typically enriched at presynaptic terminals. Three genes in humans produce closely related synuclein proteins, all of which share a large amphipathic domain capable of reversible binding to lipid vesicles. Alpha synuclein has been specifically implicated in neurodegenerative disease. Two point mutations are genetically linked to familial Parkinson's disease, and alpha synuclein appears to form the major fibrillary component of Lewy bodies. Alpha synuclein also contributes to the intracellular inclusions of multiple system atrophy, and a fragment has been found in senile plaques in Alzheimer's disease. Although their normal cellular functions are unknown, several observations suggest the synucleins may serve to integrate presynaptic signaling and membrane trafficking. Alpha synuclein has been identified as a potent and selective inhibitor of phospholipase D2, which produces phosphatidic acid (to which synuclein binds) and is believed to function in the partitioning of membranes between the cell surface and intracellular stores. We outline a hypothesis whereby synuclein supports localized, experience-dependent turnover of synaptic membranes. Such a process may be important for lifelong learning and memory functions and may be especially vulnerable to disruption in aging-associated neurodegenerative diseases.
Celis, A., H. H. Rasmussen, et al. (1999). "Short-term culturing of low-grade superficial bladder transitional cell carcinomas leads to changes in the expression levels of several proteins involved in key cellular activities." Electrophoresis20(2): 355-61.
Fresh, superficial transitional cell carcinomas (TCCs) of low-grade atypia (3 grade I, Ta; 6 grade II, Ta), as well as primary cultures derived from them were labeled with [35S]methionine for 16 h, between 2 and 6 days after inoculation. Whole protein extracts were subjected to IEF (isoelectric focusing) two-dimensional polyacrylamide gel electrophoresis (2-D PAGE) followed by autoradiography. Proteins were identified by a combination of proteomic technologies that included microsequencing, mass spectrometry, 2-D PAGE immunoblotting and comparison with the bladder TCC protein database available on the internet (http://biobase.dk/cgi-bin/celis). Comparison of the IEF 2-D gel protein profiles of fresh tumors and their primary cultures showed that the overall expression profiles were strikingly similar, although differing significantly in the levels of several proteins whose rate of synthesis was differentially regulated in at least 85% of the tumor/culture pairs as a result of the short-term culturing. Most of the proteins affected by culturing were upregulated and among them we identified components of the cytoskeleton (keratin 18, gelsolin and tropomyosin 3), a molecular chaperone (hsp 28), aldose reductase, GST pi, metastasin, synuclein, the calreticulin precursor and three polypeptides of unknown identity. Only four major proteins were downregulated, and these included two fatty acid-binding proteins (FABP:FABP5 and A-FABP) which are thought to play a role in growth control, the differentiation-associated keratin 20, and the calcium-binding protein annexin V. Proteins that were differentially regulated in only some of the cultured tumors included alpha-enolase, triosphosphate isomerase, members of the 14-3-3 family, hnRNPs F and H, PGDH, hsp (heat-shock protein) 60, BIP, the interleukin-1 receptor antagonist, the nucleolar protein B23, as well as several proteins of yet unknown identity. The suitability of in vitro bladder tumor culture models to study complex biological phenomena such as malignancy and invasion is discussed.
Burke, R. E. (1999). "alpha-Synuclein and Parkinson's disease." Brain Res Bull50(5-6): 465-6.
Brassat, D., A. Durr, et al. (1999). "[Genetics of Parkinson disease]." Rev Med Interne20(8): 709-14.
INTRODUCTION: What is the role of genetic factors in the pathophysiology of idiopathic Parkinson's disease, one of the most frequent neurodegenerative disorders? In the past two years, identification of two genes and localization of a third one have supported the hypothesis that genetics factors are involved in idiopathic Parkinson's disease. We present arguments that support such hypothesis, and describe recent advances in genetic studies of idiopathic Parkinson's disease. CURRENT KNOWLEDGE AND KEY POINTS: The first gene identified on chromosome 4 encodes alpha-synuclein. It causes a rare form of autosomal dominant Parkinson's disease. A locus on the short arm of chromosome 2 was recently identified in families with autosomal dominant Parkinson's disease. More recently, the gene encoding Parkin (located on chromosome 6) has been described. It already appears to be an important locus for juvenile parkinsonism with autosomal recessive transmission. CONCLUSION: We now have to understand how mutations in these genes lead to selective degeneration of dopaminergic neurons, and to determine whether or not they participate in the genetic susceptibility of idiopathic Parkinson's disease.
Braak, H., D. Sandmann-Keil, et al. (1999). "Extensive axonal Lewy neurites in Parkinson's disease: a novel pathological feature revealed by alpha-synuclein immunocytochemistry." Neurosci Lett265(1): 67-9.
Lewy bodies and coarse Lewy neurites are the pathological hallmarks of degenerating neurons in the brains of patients suffering from Parkinson's disease (PD). Recently, the presynaptic protein alpha-synuclein was shown to be a major component of Lewy bodies and Lewy neurites. This study demonstrates for the first time that extensive and thin alpha-synuclein-immunoreactive inclusions are present in the axonal processes of neurons.
Bennett, M. C., J. F. Bishop, et al. (1999). "Degradation of alpha-synuclein by proteasome." J Biol Chem274(48): 33855-8.
Mutations in alpha-synuclein are known to be associated with Parkinson's disease (PD). The coexistence of this neuronal protein with ubiquitin and proteasome subunits in Lewy bodies in sporadic disease suggests that alterations of alpha-synuclein catabolism may contribute to the pathogenesis of PD. The degradation pathway of alpha-synuclein has not been identified nor has the kinetics of this process been described. We investigated the degradation kinetics of both wild-type and A53T mutant 6XHis-tagged alpha-synuclein in transiently transfected SH-SY5Y cells. Degradation of both isoforms followed first-order kinetics over 24 h as monitored by the pulse-chase method. However, the t((1)/(2)) of mutant alpha-synuclein was 50% longer than that of the wild-type protein (p < 0.01). The degradation of both recombinant proteins and endogenous alpha-synuclein in these cells was blocked by the selective proteasome inhibitor beta-lactone (40 microM), indicating that both wild-type and A53T mutant alpha-synuclein are degraded by the ubiquitin-proteasome pathway. The slower degradation of mutant alpha-synuclein provides a kinetic basis for its intracellular accumulation, thus favoring its aggregation.
Bayer, T. A., P. Jakala, et al. (1999). "Neural expression profile of alpha-synuclein in developing human cortex." Neuroreport10(13): 2799-803.
Alpha-synuclein is a predominantly neuronal presynaptic protein that may play an important role during synaptogenesis and CNS development. In order to elucidate the human developmental expression profile, we used a polyclonal antiserum against the NAC domain of alpha-synuclein. In normal fetal cortex neuroectodermal precursor cells elicited staining in the soma, whereas, in adult cortex, we observed a staining pattern compatible with synaptic function. The same developmental intraneuronal redistribution was found in neurodegenerative disorders, i.e. somatic staining in neuroectodermal precursors in fetal (trisomy 21) and a synaptic pattern in adult (Down's syndrome, Alzheimer's disease) brains. RT-PCR and Western blot analysis revealed expression at all time points studied (4-7.5 months) during human brain development.
Bayer, T. A., P. Jakala, et al. (1999). "Alpha-synuclein accumulates in Lewy bodies in Parkinson's disease and dementia with Lewy bodies but not in Alzheimer's disease beta-amyloid plaque cores." Neurosci Lett266(3): 213-6.
A growing body of evidence suggests that the non-Abeta component of Alzheimer's disease amyloid precursor protein (NACP) or alpha-synuclein contributes to the neurodegenerative processes in Alzheimer's disease (AD), Parkinson's disease (PD) and dementia with Lewy bodies (DLB). In the present study antisera to the N terminus and the NAC domain of the alpha-synuclein protein were employed to elucidate the expression pattern in brains of patients with AD, PD, DLB and control specimen. Alpha-synuclein exhibited an overall punctuate expression profile compatible with a synaptic function. Interestingly, while Lewy bodies were strongly immunoreactive, none of the alpha-synuclein antisera revealed staining in mature beta-amyloid plaques in AD. These observations suggest that alpha-synuclein does not contribute to late neurodegenerative processes in AD brains.
Athanassiadou, A., G. Voutsinas, et al. (1999). "Genetic analysis of families with Parkinson disease that carry the Ala53Thr mutation in the gene encoding alpha-synuclein." Am J Hum Genet65(2): 555-8.
Arima, K., S. Hirai, et al. (1999). "Cellular co-localization of phosphorylated tau- and NACP/alpha-synuclein-epitopes in lewy bodies in sporadic Parkinson's disease and in dementia with Lewy bodies." Brain Res843(1-2): 53-61.
The precursor of the non-Abeta-component of Alzheimer's disease (AD) amyloid (NACP, alpha-synuclein) aggregates into insoluble filaments of Lewy bodies (LBs) in Parkinson's disease (PD) and dementia with LBs (DLB). The microtubule-associated protein tau is an integral component of filaments of neurofibrillary tangles (NFTs). NFTs are occasionally found in brains of PD and DLB; however, the presence of NFTs or tau-epitopes within LB-containing neurons is rare. Double-immunofluorescence study and peroxidase-immunohistochemical study in serial sections, performed to examine the co-localization of tau- and NACP-epitopes in the brainstem of PD and DLB, demonstrated that four different epitopes of tau including phosphorylation-dependent and independent ones were present in a minority of LBs, but more often than previously considered. A tau (tau2)-epitope was localized to filaments in the outer layers of brainstem-type LBs by immunoelectron microscopy. Therefore, we conclude that tau is incorporated into filaments in certain LBs. Extensive investigation has enabled us to classify this co-localization into four types: type 1, LBs with ring-shaped tau-immunoreactivity; type 2, LBs surrounded by NFTs; type 3, NACP- and tau-immunoreactive filamentous and granular masses; and type 4, NACP- and tau-immunoreactive dystrophic neurites. This study raises a new question whether aggregation and hyperphosphorylation of tau in PD and DLB are triggered by the collapse of intraneuronal organization of microtubules due to NACP-filament aggregation in neuronal perikarya and axons.
Arai, T., K. Ueda, et al. (1999). "Argyrophilic glial inclusions in the midbrain of patients with Parkinson's disease and diffuse Lewy body disease are immunopositive for NACP/alpha-synuclein." Neurosci Lett259(2): 83-6.
Argyrophilic glial inclusions occur in the midbrain of patients with Parkinson's disease (PD) and diffuse Lewy body disease (DLBD). These inclusions are immunohistochemically positive for NACP/alpha-synuclein but negative for tau protein. The results of the present study suggest that a primary degenerative process involves NACP/alpha-synuclein in PD and DLBD and that the process takes place not only in neurons but also in glial cells. Argyrophilic cytoplasmic inclusions, both glial and neuronal, in a variety of degenerative diseases may be grouped into two major categories; one related to aggregates of abnormally phosphorylated tau protein and the other to unusual accumulations of NACP/alpha-synuclein.
Alimova-Kost, M. V., N. N. Ninkina, et al. (1999). "Genomic structure and chromosomal localization of the mouse persyn gene." Genomics56(2): 224-7.
Synucleins are a family of small intracellular proteins expressed mainly in the nervous system. The involvement of synucleins in neurodegeneration and malignancy has been demonstrated, but the physiological functions of these proteins remain elusive. Further studies including generation of animals with modified persyn expression are necessary to clarify the functions of these proteins and the mechanisms of their involvement in human diseases. We cloned and determined the organization and chromosomal localization of the mouse gene coding for persyn, a member of the synuclein family. The gene is composed of five exons, and its general structure is very similar to that of the human persyn gene. Using fluorescence in situ hybridization, we assigned the persyn gene to the boundary of bands B and C on mouse chromosome 14. We found a fragment of the gene that directs expression of the persyn protein in sensory neurons and could be used for generation of transgenic animals.
