Interleukin-1A (?889) genetic polymorphism increases the risk of multiple system atrophy

Inflammation in multiple system atrophy

Misfolding protein aggregation inside or outside cells is the major pathological hallmark of several neurodegenerative diseases. Among proteinopathies are neurodegenerative diseases with atypical Parkinsonism and an accumulation of insoluble fibrillary alpha-synuclein (synucleinopathies) or hyperphosphorylated tau protein fragments (tauopathies). As there are no therapies available to slow or halt the progression of these disea ses, targeting the inflammatory process is a promising approach. The inflammatory biomarkers could also help in the differential diagnosis of Parkinsonian syndromes. Here, we review inflammation's role in multiple systems atrophy pathogenesis, diagnosis, and treatment.

Genome-wide association study identifies a new susceptibility locus in PLA2G4C for Multiple System Atrophy

To elucidate the molecular basis of multiple system atrophy (MSA), a neurodegenerative disease, we conducted a genome-wide association study (GWAS) in a Japanese MSA case/control series followed by replication studies in Japanese, Korean, Chinese, European and North American samples. In the GWAS stage rs2303744 on chromosome 19 showed a suggestive association ( P = 6.5 × 10 ^-7 ) that was replicated in additional Japanese samples ( P = 2.9 × 10 ^-6 . OR = 1.58; 95% confidence interval, 1.30 to 1.91), and then confirmed as highly significant in a meta-analysis of East Asian population data ( P = 5.0 × 10 ^-15 . Odds ratio= 1.49; 95% CI 1.35 to 1.72). The association of rs2303744 with MSA remained significant in combined European/North American samples ( P =0.023. Odds ratio=1.14; 95% CI 1.02 to 1.28) despite allele frequencies being quite different between these populations. rs2303744 leads to an amino acid substitution in PLA2G4C that encodes the cPLA2γ lysophospholipase/transacylase. The cPLA2γ-Ile143 isoform encoded by the MSA risk allele has significantly decreased transacylase activity compared with the alternate cPLA2γ-Val143 isoform that may perturb membrane phospholipids and α-synuclein biology.

Multiple system atrophy: at the crossroads of cellular, molecular and genetic mechanisms

Multiple system atrophy (MSA) is a rare oligodendroglial α-synucleinopathy characterized by neurodegeneration in striatonigral and olivopontocerebellar regions and autonomic brain centres. It causes complex cumulative motor and non-motor disability with fast progression and effective therapy is currently lacking. The difficulties in the diagnosis and treatment of MSA are largely related to the incomplete understanding of the pathogenesis of the disease. The MSA pathogenic landscape is complex, and converging findings from genetic and neuropathological studies as well as studies in experimental models of MSA have indicated the involvement of genetic and epigenetic changes; α-synuclein misfolding, aggregation and spreading; and α-synuclein strain specificity. These studies also indicate the involvement of myelin and iron dyshomeostasis, neuroinflammation, mitochondrial dysfunction and other cell-specific aspects that are relevant to the fast progression of MSA. In this Review, we discuss these findings and emphasize the implications of the complexity of the multifactorial pathogenic cascade for future translational research and its impact on biomarker discovery and treatment target definitions.

The genetic basis of multiple system atrophy

Multiple system atrophy (MSA) is a heterogenous, uniformly fatal neurodegenerative ɑ-synucleinopathy. Patients present with varying degrees of dysautonomia, parkinsonism, cerebellar dysfunction, and corticospinal degeneration. The underlying pathophysiology is postulated to arise from aberrant ɑ-synuclein deposition, mitochondrial dysfunction, oxidative stress and neuroinflammation. Although MSA is regarded as a primarily sporadic disease, there is a possible genetic component that is poorly understood. This review summarizes current literature on genetic risk factors and potential pathogenic genes and loci linked to both sporadic and familial MSA, and underlines the biological mechanisms that support the role of genetics in MSA. We discuss a broad range of genes that have been associated with MSA including genes related to Parkinson's disease (PD), oxidative stress, inflammation, and tandem gene repeat expansions, among several others. Furthermore, we highlight various genetic polymorphisms that modulate MSA risk, including complex gene-gene and gene-environment interactions, which influence the disease phenotype and have clinical significance in both presentation and prognosis. Deciphering the exact mechanism of how MSA can result from genetic aberrations in both experimental and clinical models will facilitate the identification of novel pathophysiologic clues, and pave the way for translational research into the development of disease-modifying therapeutic targets.

Cerebral mitochondrial electron transport chain dysfunction in multiple system atrophy and Parkinson's disease

Multiple system atrophy (MSA) is a neurodegenerative disease characterised by glial cytoplasmic inclusions (GCIs), containing α-synuclein. Mutated COQ2, encoding an enzyme essential for co-enzyme Q10 (CoQ10) biosynthesis, has been associated with MSA. CoQ10 is an electron carrier in the mitochondrial electron transport chain (ETC) and antioxidant. It has been shown to be deficient in MSA brain tissue, thus implicating mitochondrial dysfunction in MSA. To investigate mitochondrial dysfunction in MSA further we examined ETC activity in MSA and control brain tissue, compared with Parkinson's disease (PD) where mitochondrial dysfunction is known to be important. Using cerebellar and occipital white matter ETC complex I, II/III and IV activities were measured spectrophotometrically, selected individual components of the ETC were assessed by immunoblotting and cellular complex IV activity was analysed by enzyme histochemistry. We show decreased complex II/III activity with increased complex I and IV activity in MSA cerebellar white matter. This corresponds with the deficit in CoQ10 previously described in MSA and reflects the high regional pathological burden of GCIs. This study highlights mitochondrial dysfunction in MSA pathogenesis, suggests an influence on selective regional vulnerability to disease and points to shared disease mechanisms in α-synucleinopathies.

Association of TNF-α rs1799964 and IL-1β rs16944 polymorphisms with multiple system atrophy in Chinese Han population

BACKGROUND

Recent evidence suggested that several single nucleotide polymorphisms (SNPs) of inflammation-related genes (TNF-α rs1799964, IL-1α rs1800587, IL-1β rs16944, IL-8 rs4073, ICAM-1 rs5498) were associated with multiple system atrophy (MSA). Herein, we conducted this case-control study to evaluate the possible correlation between the five SNPs related to inflammation and MSA in Chinese Han population.

METHODS AND PATIENTS

We recruited 154 sporadic patients with MSA and 223 health controls in this study. All subjects were genotyped for the five SNPs using polymerase chain reaction amplification and Sanger sequencing.

RESULTS

TNF-α rs1799964, genotype distribution and minor allele frequency (MAF) showed significant differences between patients and controls, which might illustrate the minor allele C may increase the risk for MSA (genotype, P = 0.006, OR = 1.245, 95% CI = [1.066-1.455]; allele, P = 0.001, OR = 1.887, 95% CI = [1.303-2.733]). For rs16944, patients carrying AA genotype showed a nearly 5-year early age at onset (AAO) than GG genotype (50.52 ± 7.45 years vs. 54.90 ± 7.21 years, P = 0.037). No differences were found in genotype distribution and MAF of the five SNPs between patients with MSA with predominant cerebellar ataxia (MSA-C) and with predominant Parkinsonism (MSA-P).

CONCLUSION

Our study suggests that rs1799964 of TNF-α may act as a risk factor for MSA and the IL-1β rs16944 might be a genetic factor that modifies the AAO in MSA. Moreover, the exact mechanism of neuroinflammatory response in MSA deserves further exploration.

Genetics Underlying Atypical Parkinsonism and Related Neurodegenerative Disorders

Atypical parkinsonism syndromes, such as dementia with Lewy bodies, multiple system atrophy, progressive supranuclear palsy and corticobasal degeneration, are neurodegenerative diseases with complex clinical and pathological features. Heterogeneity in clinical presentations, possible secondary determinants as well as mimic syndromes pose a major challenge to accurately diagnose patients suffering from these devastating conditions. Over the last two decades, significant advancements in genomic technologies have provided us with increasing insights into the molecular pathogenesis of atypical parkinsonism and their intriguing relationships to related neurodegenerative diseases, fueling new hopes to incorporate molecular knowledge into our diagnostic, prognostic and therapeutic approaches towards managing these conditions. In this review article, we summarize the current understanding of genetic mechanisms implicated in atypical parkinsonism syndromes. We further highlight mimic syndromes relevant to differential considerations and possible future directions.

Evidence for α-synuclein prions causing multiple system atrophy in humans with parkinsonism

Prions are proteins that adopt alternative conformations that become self-propagating; the PrP(Sc) prion causes the rare human disorder Creutzfeldt-Jakob disease (CJD). We report here that multiple system atrophy (MSA) is caused by a different human prion composed of the α-synuclein protein. MSA is a slowly evolving disorder characterized by progressive loss of autonomic nervous system function and often signs of parkinsonism; the neuropathological hallmark of MSA is glial cytoplasmic inclusions consisting of filaments of α-synuclein. To determine whether human α-synuclein forms prions, we examined 14 human brain homogenates for transmission to cultured human embryonic kidney (HEK) cells expressing full-length, mutant human α-synuclein fused to yellow fluorescent protein (α-syn140*A53T-YFP) and TgM83(+/-) mice expressing α-synuclein (A53T). The TgM83(+/-) mice that were hemizygous for the mutant transgene did not develop spontaneous illness; in contrast, the TgM83(+/+) mice that were homozygous developed neurological dysfunction. Brain extracts from 14 MSA cases all transmitted neurodegeneration to TgM83(+/-) mice after incubation periods of ∼120 d, which was accompanied by deposition of α-synuclein within neuronal cell bodies and axons. All of the MSA extracts also induced aggregation of α-syn*A53T-YFP in cultured cells, whereas none of six Parkinson's disease (PD) extracts or a control sample did so. Our findings argue that MSA is caused by a unique strain of α-synuclein prions, which is different from the putative prions causing PD and from those causing spontaneous neurodegeneration in TgM83(+/+) mice. Remarkably, α-synuclein is the first new human prion to be identified, to our knowledge, since the discovery a half century ago that CJD was transmissible.

Multiple system atrophy: the application of genetics in understanding etiology

Classically defined phenotypically by a triad of cerebellar ataxia, parkinsonism, and autonomic dysfunction in conjunction with pyramidal signs, multiple system atrophy (MSA) is a rare and progressive neurodegenerative disease affecting an estimated 3-4 per every 100,000 individuals among adults 50-99 years of age. With a pathological hallmark of alpha-synuclein-immunoreactive glial cytoplasmic inclusions (GCIs; Papp-Lantos inclusions), MSA patients exhibit marked neurodegenerative changes in the striatonigral and/or olivopontocerebellar structures of the brain. As a member of the alpha-synucleinopathy family, which is defined by its well-demarcated alpha-synuclein-immunoreactive inclusions and aggregation, MSA's clinical presentation exhibits several overlapping features with other members including Parkinson's disease (PD) and dementia with Lewy bodies (DLB). Given the extensive fund of knowledge regarding the genetic etiology of PD revealed within the past several years, a genetic investigation of MSA is warranted. While a current genome-wide association study is underway for MSA to further clarify the role of associated genetic loci and single-nucleotide polymorphisms, several cases have presented solid preliminary evidence of a genetic etiology. Naturally, genes and variants manifesting known associations with PD (and other phenotypically similar neurodegenerative disorders), including SNCA and MAPT, have been comprehensively investigated in MSA patient cohorts. More recently variants in COQ2 have been linked to MSA in the Japanese population although this finding awaits replication. Nonetheless, significant positive associations with subsequent independent replication studies have been scarce. With very limited information regarding genetic mutations or alterations in gene dosage as a cause of MSA, the search for novel risk genes, which may be in the form of common variants or rare variants, is the logical nexus for MSA research. We believe that the application of next generation genetic methods to MSA will provide valuable insight into the underlying causes of this disease, and will be central to the identification of etiologic-based therapies.

Multiple system atrophy: genetic or epigenetic?

Multiple system atrophy (MSA) is a rare, late-onset and fatal neurodegenerative disease including multisystem neurodegeneration and the formation of α-synuclein containing oligodendroglial cytoplasmic inclusions (GCIs), which present the hallmark of the disease. MSA is considered to be a sporadic disease; however certain genetic aspects have been studied during the last years in order to shed light on the largely unknown etiology and pathogenesis of the disease. Epidemiological studies focused on the possible impact of environmental factors on MSA disease development. This article gives an overview on the findings from genetic and epigenetic studies on MSA and discusses the role of genetic or epigenetic factors in disease pathogenesis.

Update on novel familial forms of Parkinson's disease and multiple system atrophy

Parkinson's disease (PD) and multiple system atrophy (MSA) are progressive neurodegenerative disorders classified as synucleinopathies, which are defined by the presence of α-synuclein protein pathology. Genetic studies have identified a total of 18 PARK loci that are associated with PD. The SNCA gene encodes the α-synuclein protein. The first pathogenic α-synuclein p.A53T substitution was discovered in 1997; this was followed by the identification of p.A30P and p.E46K pathogenic substitutions in 1998 and 2004, respectively. In the last year, two possible α-synuclein pathogenic substitutions, p.A18T and p.A29S, and two probable pathogenic substitutions, p.H50Q and p.G51D have been nominated. Next-generation sequencing approaches in familial PD have identified mutations in the VPS35 gene. A VPS35 p.D620N substitution remains the only confirmed pathogenic substitution. A second synucleinopathy, MSA, originally was considered a sporadic condition with little or no familial aggregation. However, recessive COQ2 mutations recently were nominated to be the genetic cause in a subset of familial and sporadic MSA cases. Further studies on the clinicogenetics and pathology of parkinsonian disorders will facilitate clarification of the molecular characteristics and pathomechanisms underlying these disorders.

Genetic variants in diseases of the extrapyramidal system

Knowledge on the genetics of movement disorders has advanced significantly in recent years. It is now recognized that disorders of the basal ganglia have genetic basis and it is suggested that molecular genetic data will provide clues to the pathophysiology of normal and abnormal motor control. Progress in molecular genetic studies, leading to the detection of genetic mutations and loci, has contributed to the understanding of mechanisms of neurodegeneration and has helped clarify the pathogenesis of some neurodegenerative diseases. Molecular studies have also found application in the diagnosis of neurodegenerative diseases, increasing the range of genetic counseling and enabling a more accurate diagno-sis. It seems that understanding pathogenic processes and the significant role of genetics has led to many experiments that may in the future will result in more effective treatment of such diseases as Parkinson’s or Huntington’s. Currently used molecular diagnostics based on DNA analysis can identify 9 neurodegenerative diseases, including spinal cerebellar ataxia inherited in an autosomal dominant manner, dentate-rubro-pallido-luysian atrophy, Friedreich’s disease, ataxia with ocu-lomotorapraxia, Huntington's disease, dystonia type 1, Wilson’s disease, and some cases of Parkinson's disease.

Antidepressants reduce neuroinflammatory responses and astroglial alpha-synuclein accumulation in a transgenic mouse model of multiple system atrophy

Multiple system atrophy (MSA) is a neurodegenerative disease characterized by the pathological accumulation of alpha-synuclein (α-syn) within oligodendroglial cells. This accumulation is accompanied by neuroinflammation with astrogliosis and microgliosis, that leads to neuronal death and subsequent parkinsonism and dysautonomia. Antidepressants have been explored as neuroprotective agents as they normalize neurotrophic factor levels, increase neurogenesis and reduce neurodegeneration, but their anti-inflammatory properties have not been fully characterized. We analyzed the anti-inflammatory profiles of three different antidepressants (fluoxetine, olanzapine and amitriptyline) in the MBP1-hα-syn transgenic (tg) mouse model of MSA. We observed that antidepressant treatment decreased the number of α-syn-positive cells in the basal ganglia of 11-month-old tg animals. This reduction was accompanied with a similar decrease in the colocalization of α-syn with astrocyte markers in this brain structure. Consistent with these results, antidepressants reduced astrogliosis in the hippocampus and basal ganglia of the MBP1-hα-syn tg mice, and modulated the expression levels of key cytokines that were dysregulated in the tg mouse model, such as IL-1β. In vitro experiments in the astroglial cell line C6 confirmed that antidepressants inhibited NF-κB translocation to the nucleus and reduced IL-1β protein levels. We conclude that the anti-inflammatory properties of antidepressants in the MBP1-hα-syn tg mouse model of MSA might be related to their ability to inhibit α-syn propagation from oligodendrocytes to astroglia and to regulate transcription factors involved in cytokine expression. Our results suggest that antidepressants might be of interest as anti-inflammatory and α-syn-reducing agents for MSA and other α-synucleinopathies.

SHC2 gene copy number in multiple system atrophy (MSA)

PURPOSE

Multiple system atrophy (MSA) is a sporadic, late onset, rapidly progressing neurodegenerative disorder, which is characterized by autonomic failure, together with Parkinsonian, cerebellar, and pyramidal motor symptoms. The pathologic hallmark is the glial cytoplasmic inclusion with α-synuclein aggregates. MSA is thus an α-synucleinopathy. Recently, Sasaki et al. reported that heterozygosity for copy number loss of Src homology 2 domain containing-transforming protein 2 (SHC2) genes (heterozygous SHC2 gene deletions) occurred in DNAs from many Japanese individuals with MSA. Because background copy number variation can be distinct in different human populations, we assessed SHC2 allele copy number in DNAs from a US cohort of individuals with MSA, to determine the contribution of SHC2 gene copy number variation in an American cohort followed at a US referral center for MSA. Our cohort included 105 carefully phenotyped individuals with MSA.

METHODS

We studied 105 well-characterized patients with MSA and 5 control subjects with reduced SHC2 gene copy number. We used two TaqMan Gene Copy Number Assays, to determine the copy number of two segments of the SHC2 gene that are separated by 27 kb.

RESULTS

Assay results of DNAs from all of our 105 subjects with MSA showed 2 copies of both segments of their SHC2 genes.

CONCLUSION

Our results indicate that SHC2 gene deletions underlie few, if any, cases of well-characterized MSA in the US population. This is in contrast to the Japanese experience reported by Sasaki et al., likely reflecting heterogeneity of the disease in different genetic backgrounds.

Models of multiple system atrophy

Multiple system atrophy (MSA) is a predominantly sporadic, adult-onset, fatal neurodegenerative disease of unknown etiology. MSA is characterized by autonomic failure, levodopa-unresponsive parkinsonism, cerebellar ataxia and pyramidal signs in any combination. MSA belongs to a group of neurodegenerative disorders termed α-synucleinopathies, which also include Parkinson's disease and dementia with Lewy bodies. Their common pathological feature is the occurrence of abnormal α-synuclein positive inclusions in neurons or glial cells. In MSA, the main cell type presenting aggregates composed of α-synuclein are oligodendroglial cells . This pathological hallmark, also called glial cytoplasmic inclusions (GCIs) , is associated with progressive and profound neuronal loss in various regions of the brain. The development of animal models of MSA is justified by the limited understanding of the mechanisms of neurodegeneration and GCIs formation, which is paralleled by a lack of therapeutic strategies. Two main types of rodent models have been generated to replicate different features of MSA neuropathology. On one hand, neurotoxin-based models have been produced to reproduce neuronal loss in substantia nigra pars compacta and striatum. On the other hand, transgenic mouse models with overexpression of α-synuclein in oligodendroglia have been used to reproduce GCIs-related pathology. This chapter gives an overview of the atypical Parkinson's syndrome MSA and summarizes the currently available MSA animal models and their relevance for pre-clinical testing of disease-modifying therapies.

Myeloperoxidase inhibition ameliorates multiple system atrophy-like degeneration in a transgenic mouse model

Multiple system atrophy (MSA) is a rare and fatal α-synucleinopathy characterized by a distinctive oligodendrogliopathy with glial cytoplasmic inclusions and associated neuronal multisystem degeneration. The majority of patients presents with a rapidly progressive parkinsonian disorder and atypical features such as early autonomic failure and cerebellar ataxia. We have previously reported that complete MSA pathology can be modeled in transgenic mice overexpressing oligodendroglial α-synuclein under conditions of oxidative stress induced by 3-nitropropionic acid (3-NP) including striatonigral degeneration, olivopontocerebellar atrophy, astrogliosis, and microglial activation. Here, we show that myeloperoxidase (MPO), a key enzyme involved in the production of reactive oxygen species by phagocytic cells, is expressed in both human and mouse MSA brains. We also demonstrate that in the MSA mouse model, MPO inhibition reduces motor impairment and rescues vulnerable neurons in striatum, substantia nigra pars compacta, cerebellar cortex, pontine nuclei, and inferior olives. MPO inhibition is associated with suppression of microglial activation but does not affect 3-NP induced astrogliosis in the same regions. Finally, MPO inhibition results in reduced intracellular aggregates of α-synuclein. This study suggests that MPO inhibition may represent a novel candidate treatment strategy against MSA-like neurodegeneration acting through its anti-inflammatory and anti-oxidative properties.

Genetic players in multiple system atrophy: unfolding the nature of the beast

Multiple system atrophy (MSA) is a fatal oligodendrogliopathy characterized by prominent α-synuclein inclusions resulting in a neuronal multisystem degeneration. Until recently MSA was widely conceived as a nongenetic disorder. However, during the last years a few postmortem verified Mendelian pedigrees have been reported consistent with monogenic disease in rare cases of MSA. Further, within the last 2 decades several genes have been associated with an increased risk of MSA, first and foremost the SNCA gene coding for α-synuclein. Moreover, genes involved in oxidative stress, mitochondrial dysfunction, inflammatory processes, as well as parkinsonism- and ataxia-related genes have been implicated as susceptibility factors. In this review, we discuss the emerging evidence in favor of genetic players in MSA.

Genetic players in multiple system atrophy: unfolding the nature of the beast

Multiple system atrophy (MSA) is a fatal oligodendrogliopathy characterized by prominent α-synuclein inclusions resulting in a neuronal multisystem degeneration. Until recently MSA was widely conceived as a nongenetic disorder. However, during the last years a few postmortem verified Mendelian pedigrees have been reported consistent with monogenic disease in rare cases of MSA. Further, within the last 2 decades several genes have been associated with an increased risk of MSA, first and foremost the SNCA gene coding for α-synuclein. Moreover, genes involved in oxidative stress, mitochondrial dysfunction, inflammatory processes, as well as parkinsonism- and ataxia-related genes have been implicated as susceptibility factors. In this review, we discuss the emerging evidence in favor of genetic players in MSA.

Genetic variants of the alpha-synuclein gene SNCA are associated with multiple system atrophy

Background

Multiple system atrophy (MSA) is a progressive neurodegenerative disorder characterized by parkinsonism, cerebellar ataxia and autonomic dysfunction. Pathogenic mechanisms remain obscure but the neuropathological hallmark is the presence of α-synuclein-immunoreactive glial cytoplasmic inclusions. Genetic variants of the α-synuclein gene, SNCA, are thus strong candidates for genetic association with MSA. One follow-up to a genome-wide association of Parkinson's disease has identified association of a SNP in SNCA with MSA.

Methodology/Findings

We evaluated 32 SNPs in the SNCA gene in a European population of 239 cases and 617 controls recruited as part of the Neuroprotection and Natural History in Parkinson Plus Syndromes (NNIPPS) study. We used 161 independently collected samples for replication. Two SNCA SNPs showed association with MSA: rs3822086 (P = 0.0044), and rs3775444 (P = 0.012), although only the first survived correction for multiple testing. In the MSA-C subgroup the association strengthened despite more than halving the number of cases: rs3822086 P = 0.0024, OR 2.153, (95% CI 1.3–3.6); rs3775444 P = 0.0017, OR 4.386 (95% CI 1.6–11.7). A 7-SNP haplotype incorporating three SNPs either side of rs3822086 strengthened the association with MSA-C further (best haplotype, P = 8.7×10⁻⁴). The association with rs3822086 was replicated in the independent samples (P = 0.035).

Conclusions/Significance

We report a genetic association between MSA and α-synuclein which has replicated in independent samples. The strongest association is with the cerebellar subtype of MSA.

Trial Registration

ClinicalTrials.gov NCT00211224. [NCT00211224]

Recent developments in multiple system atrophy

Multiple system atrophy (MSA) is a rare late onset neurodegenerative disorder which presents with autonomic failure and a complicated motor syndrome including atypical parkinsonism, ataxia and pyramidal signs. MSA is a glial alpha-synucleinopathy with rapid progression and currently poor therapeutic management. This paper reviews the clinical features, natural history and novel diagnostic criteria for MSA as well as contemporary knowledge on pathogenesis based on evidence from neuropathological studies and experimental models. An outline of the rationale for managing symptomatic deterioration in MSA is provided together with a summary of novel experimental therapeutic approaches to decrease disease progression.

Associations between multiple system atrophy and polymorphisms of SLC1A4, SQSTM1, and EIF4EBP1 genes

Multiple system atrophy (MSA) is an adult-onset sporadic neurodegenerative disease. Although the etiology of MSA remains obscure, recent studies suggest that oxidative stress is associated with the pathogenesis of MSA. The aim of this study was to evaluate genetic associations between the candidate genes involved in oxidative stress and MSA in a case-control study. We examined 119 Japanese patients with MSA and 123 controls, and genotyped single-nucleotide polymorphisms (SNPs) of the following eight genes: CCAAT/enhancer-binding protein homologous protein, activating transcription factor 3, CCAAT/enhancer-binding protein-beta, sequestosome 1 (SQSTM1), cysteinyl-tRNA synthetase, solute carrier family 1A4 (SLC1A4), activating transcription factor 4, and eukaryotic translation initiation factor 4E-binding protein 1 (EIF4EBP1). SLC1A4 SNP +28833 (V398I, rs759458, genotype: Pc = 0.0186, allele: Pc = 0.0303, Pc: P-value with Bonferroni correction), two major haplotypes of SLC1A4 "T-C-C-G" and "T-C-T-A" (Pc = 0.0261 and 0.000768), two-SNP haplotypes of SQSTM1 "C-T" and "A-T" (Pc = 0.0136 and 0.0369), and the most common haplotype of EIF4EBP1 "C-T-G-C" (Pc = 0.0480) showed significant associations. This study revealed genetic associations of SLC1A4, SQSTM1, and EIF4EBP1 with MSA. These results may lend genetic support to the hypothesis that oxidative stress is associated with the pathogenesis of MSA.

Risk factors of multiple system atrophy: a case-control study in French patients

Multiple system atrophy (MSA) is a rare sporadic progressive neurodegenerative disorder. MSA risk factors are poorly known. The objectives of this case-control study were to study environmental risk factors associated with MSA. Cases were recruited through five French referral centers. Controls matched for age, gender, and living area were recruited from healthy relatives of inpatients free of any parkinsonian syndrome of the same centers. Subjects were interviewed about exposure to environmental factors (pesticides, solvents, etc.), occupation and food habits, and use of anti-inflammatory drugs. Odds ratios and 95% confident intervals (OR [95% CI]) were computed using conditional logistic regression. Seventy-one cases and 71 matched controls were included. Low education level was more frequent in cases than in controls. Controls drank more alcohol than did cases (OR = 0.5 [0.2-1.1]) and the risk of MSA decreased with increasing alcohol consumption (P = 0.04). Controls ate fish and sea food more often and drank more tea than cases. Aspirin intake was more frequent among controls than did cases (OR = 0.5 [0.2-1.0]) and the risk of MSA decreased with the frequency of intake (P = 0.0002). MSA was not associated to exposure to pesticides, solvents, and other toxics neither to occupations, except plant and machine operators and assemblers (OR = 10.0 [2.1-47.5]) where the risk of MSA increased with number of years in this occupation (P = 0.004). This case-control study provided new findings about risk factors of MSA. On another hand, it did not confirm the previously reported association between MSA and exposure to pesticides.

PRNP M129V homozygosity in multiple system atrophy vs. Parkinson's disease

Multiple system atrophy (MSA) is a neurodegenerative disorder of unknown etiology characterized by extrapyramidal, pyramidal, cerebellar, and autonomic dysfunction in any combination. We report a patient with a 4-year history of MSA who developed dementia associated with sporadic Creutzfeldt-Jakob disease (CJD). Our proband was MM homozygous for the M129V polymorphism within the prion protein gene (PRNP), a known risk factor for CJD. We conducted a case-control study to test the hypothesis that homozygosity for the M129V polymorphism of PRNP occurs more frequently in MSA in comparison to Parkinson's disease and healthy volunteers. A total of 63 patients with MSA, 54 age-, race- and gendermatched controls with Parkinson's disease, and 126 matched healthy volunteers were studied. The genotype analysis revealed no significant difference in the codon 129 genotype distribution in MSA as compared to controls. Nonetheless, the frequencies of the MM and VV genotypes were higher in MSA than in Parkinson's disease. Thus, homozygosity, particularly VV homozygosity, at codon 129 of PRNP is associated with MSA compared to a clinically related but pathophysiologically distinct alpha-synucleinopathy. Considering the possibility that the prion protein contributes to the pathogenesis of MSA would require confirmation of these findings in an independent patient population.

Interleukin-1 alpha polymorphism has influence on late-onset sporadic Parkinson's disease in Taiwan

Inflammatory events may contribute to the pathogenesis of Parkinson's disease (PD) and interleukin 1 (IL-1) may exert both neurotoxic and neuroprotective effects. We conducted a case-control study in a cohort of 493 PD cases and 388 ethnically matched controls to investigate the association of IL-1alpha C-889T and IL-1beta C-511T polymorphisms with the risk of PD. No significant difference in the genotype distribution of the analyzed polymorphisms was found between PD and controls. However, after stratification by age, individuals over 70 years of age carrying IL-1alpha-889 C/T genotype demonstrated a significant decrease in risk of developing PD (OR = 0.44; 95% CI = 0.22-0.88, p = 0.021) and the decrease is strengthened by IL-1beta-511 T-carrying genotype (OR = 0.28; 95% CI = 0.11-0.71, p = 0.008). Our data suggest that IL-1alpha, acting synergistically with IL-1beta, plays role in PD susceptibility among Taiwanese people older than 70 years of age.

Pathology and genetics of multiple system atrophy: an approach to determining genetic susceptibility spectrum

Recent advances in the molecular pathology and genetics of multiple system atrophy (MSA) indicate that the disease involves plural pathogenic mechanisms. The determination of the morphological spectrum of MSA using quantitative pathological analysis points to the need for further investigation to determine the population-bound phenotype distribution of MSA. These notions support the hypothesis that a spectrum of genetic susceptibility factors underlies MSA pathogenesis. A possibly effective strategy for determining this genetic susceptibility spectrum is to perform an association study of important genes for neurodegenerative diseases, which are prevalent in a population, using linkage disequilibrium mapping in MSA patients with well-characterized morphological phenotypes.

Glial degeneration and reactive gliosis in alpha-synucleinopathies: the emerging concept of primary gliodegeneration

The concept of gliodegenerative diseases has not been widely established although there is accumulating evidence that glial cells may represent a primary target of degenerative disease processes. In the central nervous system (CNS), examples that provide a "proof of concept" include at least one alpha-synucleinopathy, multiple system atrophy (MSA), but this disease is conventionally discussed under the heading of "neurodegeneration". Additional evidence in support of primary glial affection has been reported in neurodegenerative disorders such as Parkinson's disease, Alzheimer's disease and transmissible spongiform encephalopathies. Based on biochemical, genetic and transcriptomic studies it is also becoming increasingly clear that the molecular changes measured in whole tissue extracts, e.g. obtained from Parkinson's disease brain, are not based on a purely neuronal contribution. This important evidence has been missed in cell culture or laser capture work focusing on the neuronal cell population. Studies of animal and in vitro models of disease pathogenesis additionally suggest glial accountability for some CNS degenerative processes. This review provides a critical analysis of the evidence available to date in support of the concept of gliodegeneration, which we propose to represent an essential although largely disregarded component of the spectrum of classical "neurodegeneration". Examples from the spectrum of alpha-synucleinopathies are presented.

MSA-C is the predominant clinical phenotype of MSA in Japan: Analysis of 142 patients with probable MSA

We investigated the clinical features and mode of disease progression in 142 patients with probable multiple system atrophy (MSA) according to the Consensus Criteria. The subjects included 84 men and 58 women with a mean age at onset of 58.2+/-7.1 years (range: 38-79 years). Cerebellar signs were detected in 87.3% of these patients at the time of initial examination, and were found in 95.1% of them at latest follow-up. MSA-C was diagnosed in 83.8% of the patients at their first examination. Parkinsonism was initially detected in 28.9% of the patients, increasing to 51.4% at the latest follow-up. Among all of the subjects, only 16.2% were classified as having MSA-P on initial examination. At the latest follow-up, parkinsonian features had become predominant over cerebellar features in 24.6% of the 65 patients with MSA-C who were followed for more than 3 years. Although parkinsonism usually masked the signs of cerebellar involvement in MSA-C patients, none of the patients with MSA-P at an early stage showed predominance of cerebellar features at the latest follow-up. Parkinsonism is the predominant feature of MSA among Western patients, even at an early stage, but this study showed that cerebellar deficits are the main feature in Japanese patients. This difference of disease manifestations between ethnic groups suggests that genetic factors may influence the clinical phenotype of MSA.

Heredity in multiple system atrophy

We investigated the family histories of 157 Japanese patients with probable or possible multiple system atrophy (MSA). A family history of neurodegenerative disorders was only detected in three MSA patients (1.9%). We evaluated these patients by careful neurological examination, neuroimaging studies, and genetic studies to exclude hereditary spinocerebellar ataxia with a similar clinical phenotype to MSA. The results indicated that one of them had a family history of MSA. Although the familial presence of neurodegenerative disorders is rare in MSA patients, the existence of such cases suggests that MSA may have a genetic background.

Animal models of multiple system atrophy

Multiple system atrophy (MSA) is a fatal neurodegenerative disorder presenting with autonomic failure and motor impairment, primarily comprising L-dopa-resistant parkinsonism but occasionally involving cerebellar ataxia. These features result from progressive multisystem neuronal loss that is associated with oligodendroglial alpha-synuclein inclusions. The growing number of animal models for MSA reflects the search for a preclinical test-bed for elucidating MSA pathogenesis and for developing novel therapeutic interventions. Here, the currently available MSA animal models will be reviewed and leads for future research will be identified.

Interleukin-8, intercellular adhesion molecule-1 and tumour necrosis factor-α gene polymorphisms and the risk for multiple system atrophy

In a case-control study using a clinically well-defined group of 41 multiple system atrophy (MSA) patients and 93 control subjects, the interleukin (IL)-8 (-251) TT genotype was associated with an approximately fourfold increased risk for MSA and, furthermore, this risk increased elevenfold with the simultaneous presence of the intercellular adhesion molecule-1 (ICAM-1: E469K) KK genotype, suggesting a gene-gene interaction. These data support a role for inflammation-related genes in risk for MSA.