Global DNA methylation is not elevated in blood samples from Machado-Joseph disease mutation carriers.

Machado-Joseph disease (MJD) is an autosomal dominant spinocerebellar ataxia (SCA) caused by a polyglutamine expansion in the ataxin-3 protein, which initiates a cascade of pathogenic events, including transcriptional dysregulation. Genotype-phenotype correlations in MJD are incomplete, suggesting an influence of additional factors, such as epigenetic modifications, underlying the MJD pathogenesis. DNA methylation is known to impact the pathophysiology of neurodegenerative disorders through gene expression regulation and increased methylation has been reported for other SCAs. In this work we aimed to analyse global methylation in MJD carriers. Global 5-mC levels were quantified in blood samples of 33 MJD mutation carriers (patients and preclinical subjects) and 33 healthy controls, matched by age, sex, and smoking status. For a subset of 16 MJD subjects, a pilot follow-up analysis with two time points was also conducted. No differences were found in median global 5-mC levels between MJD mutation carriers and controls and no correlations between methylation levels and clinical or genetic variables were detected. Also, no alterations in global 5-mC levels were observed over time. Our findings do not support an increase in global blood methylation levels associated with MJD.

Tau and neurofilament light-chain as fluid biomarkers in spinocerebellar ataxia type 3.

BACKGROUND AND PURPOSE: Clinical trials in spinocerebellar ataxia type 3 (SCA3) will require biomarkers for use as outcome measures. METHODS: To evaluate total tau (t-tau), glial fibrillary acidic protein (GFAP), ubiquitin carboxy-terminal hydrolase L1 (UCHL1) and neurofilament light-chain (NfL) as fluid biomarkers in SCA3, ATXN3 mutation carriers (n = 143) and controls (n = 172) were clinically assessed, and the plasma concentrations of the four proteins were analysed on the Simoa HD-1 platform. Eleven ATXN3 mutation carrier cerebrospinal fluid samples were analysed for t-tau and phosphorylated tau (p-tau181 ). A transgenic SCA3 mouse model (MJDTg) was used to measure cerebellar t-tau levels. RESULTS: Plasma t-tau levels were higher in mutation carriers below the age of 50 compared to controls, and the Inventory of Non-Ataxia Signs was associated with t-tau in ataxic patients (p = 0.004). Pre-ataxic carriers showed higher cerebrospinal fluid t-tau and p-tau181 concentrations compared to ataxic patients (p = 0.025 and p = 0.014, respectively). Cerebellar t-tau was elevated in MJDTg mice compared to wild-type (p = 0.033) only in the early stages of the disease. GFAP and UCHL1 did not show higher levels in mutation carriers compared to controls. Plasma NfL concentrations were higher in mutation carriers compared to controls, and differences were greater for younger carriers. The Scale for the Assessment and Rating of Ataxia was the strongest predictor of NfL in ataxic patients (p < 0.001). CONCLUSION: Our results suggest that tau might be a marker of early disease stages in SCA3. NfL can discriminate mutation carriers from controls and is associated with different clinical variables. Longitudinal studies are required to confirm their potential role as biomarkers in clinical trials.

Plasma neurofilament light chain predicts cerebellar atrophy and clinical progression in spinocerebellar ataxia.

Neurofilament light chain (NfL) is a marker of brain atrophy and predictor of disease progression in rare diseases such as Huntington Disease, but also in more common neurological disorders such as Alzheimer's disease. The aim of this study was to measure NfL longitudinally in autosomal dominant spinocerebellar ataxias (SCAs) and establish correlation with clinical and imaging parameters. We enrolled 62 pathological expansions carriers (17 SCA1, 13 SCA2, 19 SCA3, and 13 SCA7) and 19 age-matched controls in a prospective biomarker study between 2011 and 2015 and followed for 24 months at the Paris Brain Institute. We performed neurological examination, brain 3 T MRI and plasma NfL measurements using an ultrasensitive single-molecule array at baseline and at the two-year follow-up visit. We evaluated NfL correlations with ages, CAG repeat sizes, clinical scores and volumetric brain MRIs. NfL levels were significantly higher in SCAs than controls at both time points (p < 0.001). Age-adjusted NfL levels were significantly correlated at baseline with clinical scores (p < 0.01). We identified optimal NfL cut-off concentrations to differentiate controls from carriers for each genotype (SCA1 16.87 pg/mL, SCA2, 19.1 pg/mL, SCA3 16.04 pg/mL, SCA7 16.67 pg/mL). For all SCAs, NfL concentration was stable over two years (p = 0.95) despite a clinical progression (p < 0.0001). Clinical progression between baseline and follow-up was associated with higher NfL concentrations at baseline (p = 0.04). Of note, all premanifest carriers with NfL levels close to cut off concentrations had signs of the disease at follow-up. For all SCAs, the higher the observed NfL, the lower the pons volume at baseline (p < 0.01) and follow-up (p = 0.02). Higher NfL levels at baseline in all SCAs predicted a decrease in cerebellar volume (p = 0.03). This result remained significant for SCA2 only among all genotypes (p = 0.02). Overall, plasma NfL levels at baseline in SCA expansion carriers predict cerebellar volume change and clinical score progression. NfL levels might help refine inclusion criteria for clinical trials in carriers with very subtle signs.

Which Factors in Spinocerebellar Ataxia Type 3 Patients Are Associated with Restless Legs Syndrome/Willis-Ekbom Disease?

There is evidence of a higher prevalence of restless legs syndrome/Willis-Ekbom disease (RLS/WED) in individuals with spinocerebellar ataxia type 3 (SCA3), although the factors underlying this association remain unknown. The present study aimed to determine the prevalence of RLS/WED in SCA3 patients and to investigate which factors of SCA3 patients are associated with presence of RLS/WED. From February to August of 2006, we carried out clinical interviews in 40 controls and 40 SCA3 patients, diagnosed and followed up at Faculty of Medicine of Ribeirão Preto, University of São Paulo. Twenty-seven SCA3 patients were submitted to a detailed clinical protocol, electroneuromyography, blood work up, polysomnography (PSG), suggested immobilization test (SIT), and magnetic resonance image (MRI). RLS/WED was found in 27.5% of SCA3 patients and 2.5% of normal controls (p = 0.003). The factors related to RLS/WED in SCA3 patients were female gender, age at start of the symptoms of ataxia after 30 years, presence of peripheral neuropathy, and documented iron deficiency. Among SCA3 patients, those with RLS showed higher values of maximal discomfort level and discomfort level sum compared to non-RLS individuals on SIT. There is a relation between RLS/WED and SCA3, which seems to be resultant of different factors whose identification could improve the quality of assistance to those patients as well as to promote a better comprehension of the pathophysiology of both RLS/WED and SCA3.

Association of serum neurofilament light and disease severity in patients with spinocerebellar ataxia type 3.

OBJECTIVE: To investigate serum neurofilament light protein (sNfL) levels in patients with spinocerebellar ataxia type 3 (SCA3) and to determine whether they are associated with disease severity. METHODS: This cross-sectional study enrolled 185 healthy controls and 235 ATXN3 mutation carriers (17 asymptomatic stage, 20 preclinical stage, and 198 ataxic stage). We measured sNfL levels with the single molecule array (Simoa) platform. Clinical disease severity was assessed using the Scale of Assessment and Rating of Ataxia (SARA) and the Inventory of Nonataxia Signs (INAS). In a subgroup of 50 ataxic stage patients, we further evaluated the gray matter volume and the integrity of white matter fibers by MRI. RESULTS: sNfL concentrations were elevated in asymptomatic, preclinical, and ataxic ATXN3 mutation carriers compared to controls (12.18 [10.20-13.92], 21.84 [18.37-23.45], 36.06 [30.04-45.90], and 8.24 [5.92-10.84] pg/mL, median [interquartile range], respectively, p < 0.001). sNfL correlated with SARA (r = 0.406, 95% confidence interval [CI] 0.284-0.515, p < 0.0001) and INAS (r = 0.375, 95% CI 0.250-0.487, p < 0.0001), and remained significant after adjustment for age and CAG repeats. In addition, we observed negative correlations of the sNfL with gray matter volume in the left precentral gyrus and the left paracentral lobule as well as with the mean diffusivity in widespread white matter tracts. CONCLUSION: Our results demonstrate that sNfL levels are increased in SCA3 and are associated with clinical disease severity, which supports sNfL as a biomarker for disease severity in SCA3. CLASSIFICATION OF EVIDENCE: This study provides Class II evidence that in patients with SCA3, sNfL elevations are associated with clinical disease severity.

Neurofilaments in spinocerebellar ataxia type 3: blood biomarkers at the preataxic and ataxic stage in humans and mice.

With molecular treatments coming into reach for spinocerebellar ataxia type 3 (SCA3), easily accessible, cross-species validated biomarkers for human and preclinical trials are warranted, particularly for the preataxic disease stage. We assessed serum levels of neurofilament light (NfL) and phosphorylated neurofilament heavy (pNfH) in ataxic and preataxic subjects of two independent multicentric SCA3 cohorts and in a SCA3 knock-in mouse model. Ataxic SCA3 subjects showed increased levels of both NfL and pNfH. In preataxic subjects, NfL levels increased with proximity to the individual expected onset of ataxia, with significant NfL elevations already 7.5 years before onset. Cross-sectional NfL levels correlated with both disease severity and longitudinal disease progression. Blood NfL and pNfH increases in human SCA3 were each paralleled by similar changes in SCA3 knock-in mice, here also starting already at the presymptomatic stage, closely following ataxin-3 aggregation and preceding Purkinje cell loss in the brain. Blood neurofilaments, particularly NfL, might thus provide easily accessible, cross-species validated biomarkers in both ataxic and preataxic SCA3, associated with earliest neuropathological changes, and serve as progression, proximity-to-onset and, potentially, treatment-response markers in both human and preclinical SCA3 trials.

Protocol for the Characterization of the Cytosine-Adenine-Guanine Tract and Flanking Polymorphisms in Machado-Joseph Disease: Impact on Diagnosis and Development of Gene-Based Therapies.

Polyglutamine spinocerebellar ataxias (SCAs) constitute a group of autosomal dominantly inherited neurodegenerative disorders with considerable phenotypic overlap. Definitive diagnoses rely on the detection of a mutation in each associated locus, comprising the abnormal expansion of the trinucleotide cytosine-adenine-guanine (CAG) in coding exons. Assessment of single nucleotide polymorphisms associated with the CAG expansion in the context of SCAs is also relevant for improving molecular diagnosis and for generating novel therapeutic strategies. The current study is focused on Machado-Joseph disease/SCA type 3, with the aim of developing a protocol for the accurate determination of the CAG length in exon 10 of the human ATXN3 gene and to characterize flanking polymorphisms. A single pair of primers was designed and validated, and two complementary PCR-based methods were established. In method I, PCR amplicons were cloned and sequenced, allowing the assessment of three single nucleotide polymorphisms in the vicinity of the CAG repeat (C987GG/G987GG, TAA1118/TAC1118, and C1178/A1178), which can constitute potential targets for personalized gene-based therapies. Method II combines PCR, capillary electrophoresis, and a size correction formula, enabling a time and cost-effective determination of the number of CAGs. The established protocol paves the way to overcome technical difficulties related to the molecular characterization of the CAG motif and intragenic polymorphisms in the context of Machado-Joseph disease/SCA type 3 and may prove useful when applied to other polyglutamine SCAs.

Neurofilament light chain is a promising serum biomarker in spinocerebellar ataxia type 3.

BACKGROUND: Spinocerebellar ataxia type 3 (SCA3) is the most common subtype of autosomal dominantly inherited spinocerebellar ataxias (SCAs). No validated blood biomarker is available to assess either disease progression or therapeutic response. Neurofilament light chain (NfL) was recently proposed as a serum biomarker for many neurodegenerative disorders. The present study investigated whether NfL was a promising serum biomarker for SCA3. METHODS: Seventeen SCA3 patients and 9 controls were enrolled in cohort A, and 116 SCA3 individuals (preclinical and patients) and 91 controls were recruited as cohort B. We assessed whether serum NfL correlated with cerebrospinal fluid (CSF) NfL in cohort A and correlations between serum NfL levels and clinical features and brain volumes were determined in cohort B. The single-molecule array method was used to measure serum NfL levels. Disease severity was determined using the scale for the assessment and rating of ataxia (SARA) and the international cooperative ataxia rating scale (ICARS). Cerebellar and brainstem volumes were assessed using MRI neuroimaging measurements. RESULTS: Serum/CSF NfL levels in cohort A were elevated in SCA3 patients, and serum and CSF NfL exhibited a significant positive correlation (r = 0.9179, p < 0.0001). Levels of serum NfL in cohort B were significantly higher in preclinical SCA3 (15.03 ± 7.49 vs 6.88 ± 2.72 pg/ mL, p < 0.0001) and manifest SCA3 subjects (37.56 ± 13.47 vs 9.07 ± 6.02 pg/ mL, p < 0.0001) compared to those in controls. Serum NfL concentrations increased from early disease stage to the next stage. Levels of serum NfL in ATXN3 mutation carriers were positively associated with SARA (r = 0.5458, p < 0.0001) and ICARS scores (r = 0.5522, p < 0.0001). Significant negative associations with cerebellar volumes (r = - 0.4217, p = 0.0003) and brainstem volumes (r = - 0.4263, p = 0.0003) were observed. All changes remained significant after adjustment for age and CAG repeat. CONCLUSIONS: Levels of serum NfL were significantly elevated in SCA3 individuals and correlated with disease severity. Serum NfL is a promising serum biomarker of disease onset and progression, and a potential candidate biomarker of treatment response in SCA3.

Selection of Reference Genes for Normalization of Gene Expression Data in Blood of Machado-Joseph Disease/Spinocerebellar Ataxia Type 3 (MJD/SCA3) Subjects.

Alongside with the emergent clinical trials for Machado-Joseph disease/Spinocerebellar ataxia type 3 (MJD/SCA3) comes the need to identify molecular biomarkers of disease that can be tracked throughout the trial. MJD is an autosomal dominant neurodegenerative disorder caused by expansion of a CAG repeat in the coding region of the ATXN3 gene. Previous findings indicate the potential of transcriptional alterations in blood of MJD patients as biomarkers of disease. Accurate quantification of gene expression levels by quantitative real-time PCR (qPCR) depends on data normalization, usually performed using reference genes. Because the expression level of routinely used housekeeping genes may vary in multiple biological and experimental conditions, reference gene controls should be validated in each specific experimental design. Here, we aimed to evaluate the expression behavior of five housekeeping genes previously reported as stably expressed in peripheral blood of patients from several disorders-peptidylprolyl isomerase B (PPIB), TNF receptor associated protein 1 (TRAP1), beta-2-microglobulin (B2M), 2,4-dienoyl-CoA reductase 1 (DECR1), and folylpolyglutamate synthase (FPGS). Expression levels of these five genes were assessed by qPCR in blood from MJD subjects (preataxic and patients) and matched controls. While all housekeeping genes, here studied, were stably expressed in our sets of samples, TRAP1 showed to be the most stable gene by NormFinder and BestKeeper. We, therefore, conclude that any of these genes could be used as reference gene in future qPCR studies using blood samples from MJD subjects.

Identification of a potential exosomal biomarker in spinocerebellar ataxia Type 3/Machado-Joseph disease.

Aim: To identify spinocerebellar ataxia Type 3 (SCA3)-related exosomal biomarkers and the underlying mechanisms. Materials & methods: Exosomal RNAs from plasma and cerebrospinal fluid (CSF) were extracted from 24 SCA3 patients and 22 controls, respectively. Small RNA sequencing and quantitative PCR verification were performed. Gene ontology annotation and Kyoto Encyclopedia of Genes and Genomes pathway analyses of the results were carried out. Results: One novel miRNA is notably downregulated in plasma-derived exosomes, while upregulated in CSF-derived exosomes of SCA3 patients. Besides, it is successively upregulated in CSF-derived exosomes from Type 1, Type 2 and Type 3 groups. The downstream target genes were enriched in protein processing in endoplasmic reticulum and axon guidance. Conclusion: One exosomal biomarker was identified in SCA3, and this is the first time to report an exosomal miRNA as a biomarker in SCA3 internationally.

Accumulation of Mitochondrial DNA Common Deletion Since The Preataxic Stage of Machado-Joseph Disease.

Molecular alterations reflecting pathophysiologic changes thought to occur many years before the clinical onset of Machado-Joseph disease (MJD)/spinocerebellar ataxia type 3 (SCA3), a late-onset polyglutamine disorder, remain unidentified. The absence of molecular biomarkers hampers clinical trials, which lack sensitive measures of disease progression, preventing the identification of events occurring prior to clinical onset. Our aim was to analyse the mtDNA content and the amount of the common deletion (m.8482_13460del4977) in a cohort of 16 preataxic MJD mutation carriers, 85 MJD patients and 101 apparently healthy age-matched controls. Relative expression levels of RPPH1, MT-ND1 and MT-ND4 genes were assessed by quantitative real-time PCR. The mtDNA content was calculated as the difference between the expression levels of a mitochondrial gene (MT-ND1) and a nuclear gene (RPPH1); the amount of mtDNA common deletion was calculated as the difference between expression levels of a deleted (MT-ND4) and an undeleted (MT-ND1) mitochondrial genes. mtDNA content in MJD carriers was similar to that of healthy age-matched controls, whereas the percentage of the common deletion was significantly increased in MJD subjects, and more pronounced in the preclinical stage (p < 0.05). The BCL2/BAX ratio was decreased in preataxic carriers compared to controls, suggesting that the mitochondrial-mediated apoptotic pathway is altered in MJD. Our findings demonstrate for the first time that accumulation of common deletion starts in the preclinical stage. Such early alterations provide support to the current understanding that any therapeutic intervention in MJD should start before the overt clinical phenotype.

A stably self-renewing adult blood-derived induced neural stem cell exhibiting patternability and epigenetic rejuvenation.

Recent reports suggest that induced neurons (iNs), but not induced pluripotent stem cell (iPSC)-derived neurons, largely preserve age-associated traits. Here, we report on the extent of preserved epigenetic and transcriptional aging signatures in directly converted induced neural stem cells (iNSCs). Employing restricted and integration-free expression of SOX2 and c-MYC, we generated a fully functional, bona fide NSC population from adult blood cells that remains highly responsive to regional patterning cues. Upon conversion, low passage iNSCs display a profound loss of age-related DNA methylation signatures, which further erode across extended passaging, thereby approximating the DNA methylation age of isogenic iPSC-derived neural precursors. This epigenetic rejuvenation is accompanied by a lack of age-associated transcriptional signatures and absence of cellular aging hallmarks. We find iNSCs to be competent for modeling pathological protein aggregation and for neurotransplantation, depicting blood-to-NSC conversion as a rapid alternative route for both disease modeling and neuroregeneration.

Promoter Variation and Expression Levels of Inflammatory Genes IL1A, IL1B, IL6 and TNF in Blood of Spinocerebellar Ataxia Type 3 (SCA3) Patients.

Age at onset in spinocerebellar ataxia type 3 (SCA3/MJD) is incompletely explained by the size of the CAG tract at the ATXN3 gene, implying the existence of genetic modifiers. A role of inflammation in SCA3 has been postulated, involving altered cytokines levels; promoter variants leading to alterations in cytokines expression could influence onset. Using blood from 86 SCA3 patients and 106 controls, this work aimed to analyse promoter variation of four cytokines (IL1A, IL1B, IL6 and TNF) and to investigate the association between variants detected and their transcript levels, evaluated by quantitative PCR. Moreover, the effect of APOE isoforms, known to modulate cytokines, was investigated. Correlations between cytokine variants and onset were tested; the cumulative modifier effects of cytokines and APOE were analysed. Patients carrying the IL6*C allele had a significant earlier onset (4 years in average) than patients carrying the G allele, in agreement with lower mRNA levels produced by IL6*C carriers. The presence of APOE*ɛ2 allele seems to anticipate onset in average 10 years in patients carrying the IL6*C allele; a larger number of patients will be needed to confirm this result. These results highlight the pertinence of conducting further research on the role of cytokines as SCA3 modulators, pointing to the presence of shared mechanisms involving IL6 and APOE.

Cytokines in Machado Joseph Disease/Spinocerebellar Ataxia 3.

The aim of the present study is to describe the serum concentrations of a broad spectrum of cytokines in symptomatic and asymptomatic carriers of Machado Joseph disease (SCA3/MJD) CAG expansions. Molecularly confirmed carriers and controls were studied. Age at onset, disease duration, and clinical scales Scale for the Assessment and Rating of Ataxia (SARA), Neurological Examination Score for Spinocerebellar Ataxias (NESSCA), SCA Functional Index (SCAFI), and Composite Cerebellar Functional Score (CCFS) were obtained from the symptomatic carriers. Serum was obtained from all individuals and a cytokine panel "consisted of" eotaxin, granulocyte-macrophage colony-stimulating factor (GM-CSF), interferon (IFN)-α, IFN-γ, interleukin (IL)-1ß, IL-1RA, IL-2, IL-2R, IL-4, IL-5, IL-6, IL-7, IL-8, IL-10, IL-12, IL-13, IL-15, IL-17, interferon gamma-induced protein (IP)-10, monocyte chemoattractant protein (MCP)-1, monokine induced by gamma interferon (MIG), macrophage inflammatory protein (MIP)-a, MIP-b, regulated on activation, normal T cell expressed and secreted (RANTES) and tumor necrosis factor (TNF)-α was analyzed. In a subgroup of symptomatic carriers, the cytokine panel was repeated after 360 days. Cytokine distribution among groups was studied by discriminant analysis; changes in serum levels after 360 days were studied by generalized estimation equation. Sixty-six symptomatic carriers, 13 asymptomatic carriers, and 43 controls were studied. No differences in cytokine patterns were found between controls and carriers of the CAG expansions or between controls and symptomatic carriers only. In contrast, eotaxin concentrations were significantly higher in asymptomatic than in symptomatic carriers or in controls (p = 0.001, ANCOVA). Eotaxin did not correlate with age, disease duration, CAG expansion, NESSCA score, and SARA score. Among symptomatic carriers, eotaxin dropped after 360 days (p = 0.039, GEE). SCA3/MJD patients presented a benign pattern of serum cytokines. In contrast, levels of eotaxin, a peptide secreted by astrocytes, were elevated in the asymptomatic carriers, suggesting that a specific response of these cells can be related to symptom progression, in SCA3/MJD.

Novel candidate blood-based transcriptional biomarkers of Machado-Joseph disease.

BACKGROUND: Machado-Joseph disease (or spinocerebellar ataxia type 3) is a late-onset polyglutamine neurodegenerative disorder caused by a mutation in the ATXN3 gene, which encodes for the ubiquitously expressed protein ataxin-3. Previous studies on cell and animal models have suggested that mutated ataxin-3 is involved in transcriptional dysregulation. Starting with a whole-transcriptome profiling of peripheral blood samples from patients and controls, we aimed to confirm abnormal expression profiles in Machado-Joseph disease and to identify promising up-regulated genes as potential candidate biomarkers of disease status. METHODS: The Illumina Human V4-HT12 array was used to measure transcriptome-wide gene expression in peripheral blood samples from 12 patients and 12 controls. Technical validation and validation in an independent set of samples were performed by quantitative real-time polymerase chain reaction (PCR). RESULTS: Based on the results from the microarray, twenty six genes, found to be up-regulated in patients, were selected for technical validation by quantitative real-time PCR (validation rate of 81% for the up-regulation trend). Fourteen of these were further tested in an independent set of 42 patients and 35 controls; 10 genes maintained the up-regulation trend (FCGR3B, CSR2RA, CLC, TNFSF14, SLA, P2RY13, FPR2, SELPLG, YIPF6, and GPR96); FCGR3B, P2RY13, and SELPLG were significantly up-regulated in patients when compared with controls. CONCLUSIONS: Our findings support the hypothesis that mutated ataxin-3 is associated with transcription dysregulation, detectable in peripheral blood cells. Furthermore, this is the first report suggesting a pool of up-regulated genes in Machado-Joseph disease that may have the potential to be used for fine phenotyping of this disease. © 2015 International Parkinson and Movement Disorder Society.

High Serum GFAP Levels in SCA3/MJD May Not Correlate with Disease Progression.

Spinocerebellar ataxia type 3(SCA3), also known as Machado-Joseph disease (MJD), is the most frequent subtype of autosomal dominant inherited spinocerebellar ataxias, which caused by the expansion of CAG repeats in the ATXN3 gene. The number of CAG repeats of the abnormal allele determines the rate of disease progression in patients with SCA3/MJD. Markers to assess the clinical severity, to predict the course of illness and to monitor the efficacy of therapeutic measures, can be clinical, biological, and radiological. Here, we aimed to explore whether the serum glial fibrillary acidic protein (GFAP) may act as a biomarker in SCA3/MJD patients and to evaluate the correlation between some markers with the number of CAG repeats in SCA3/MJD patients. We showed that the serum levels of GFAP were significantly higher in SCA3/MJD patients than in controls. There was a strong positive correlation between the age-adjusted GFAP levels with the number of CAG repeats. Age-adjusted International Cooperative Ataxia Rating Scale (ICARS) scores and Scale for the Assessment and Rating of Ataxia (SARA) scores correlated with the number of CAG repeats. Raw scores and disease duration-adjusted GFAP levels, ICARS scores, and SARA scores were not correlated with the number of CAG repeats. Our results reveal novel evidence for the role of the triplet expansion in SCA3/MJD-associated neuronal damage.

MicroRNA profiling in the serums of SCA3/MJD patients.

Spinocerebellar ataxia type 3/Machado-Joseph disease (SCA3/MJD) is the most common type of spinocerebellar ataxia in China. However, the pathogenesis of SCA3/MJD is still unknown. MicroRNAs (miRNAs) have been repeatedly demonstrated to exist in human peripheral serum in a bio-stable form and have been shown to be useful biomarkers for other neurodegenerative disorders. However, no study of SCA3/MJD patients has assessed specific changes in regulatory miRNAs. Therefore, we systematically used the miRCURYTM LNA Array, followed by quantitative real-time polymerase chain reaction validation, to access miRNA expression levels in the serums from SCA3/MJD patients. Our results show that miR-25, miR-125b, miR-29a, and miR-34b could be potential biomarkers for SCA3/MJD and could be used to further investigate the pathogenesis of SCA3/MJD and drug development.

Association between Machado-Joseph disease and oxidative stress biomarkers.

Spinocerebellar ataxia type 3, also called Machado-Joseph disease (MJD), is an hereditary autosomal dominant neurodegenerative disease that affects the cerebellum and its afferent and efferent connections. Since the mechanism by which mutant ataxin-3 eventually leads to neuronal death is poorly understood, additional investigations to clarify the biological alterations related to Machado-Joseph disease are necessary. Recent investigations suggest that oxidative stress may contribute significantly to Machado-Joseph disease. We compared markers of oxidative stress between Machado-Joseph disease and healthy control subjects. The results showed that Machado-Joseph patients have higher catalase levels and lower thiol protein levels compared to control subjects. The peripheral blood lymphocyes of MJD patients also showed higher levels of DNA damage by the comet assay than control subjects. Our results corroborate the hypothesis that the oxidative stress is associated with MJD patients. However, whether strategies to increase cellular antioxidative capacity may be effective therapies for the treatment of Machado-Joseph disease is an open question.

Is neuropathy involved with restless legs syndrome in Machado-Joseph disease?

OBJECTIVE: To evaluate a group of spinocerebellar ataxia type 3 (SCA3) or Machado-Joseph disease (MJD) (SCA3/MJD) patients and assess whether there is an association between neuropathy and serum ferritin levels and restless legs syndrome (RLS). METHODS: Twenty-six SCA3/MJD patients underwent electromyography studies to check for neuropathy. Their serum ferritin levels were measured as well. These findings were evaluated based on the presence or not of RLS and its severity. RESULTS: The proportion of neuropathy in the RLS group was not significantly higher compared to the non-RLS group (23 vs. 15%, Fisher's exact test, p = 1.000). Furthermore, no association was found between RLS and ferritin levels. CONCLUSION: We found no correlation between neuropathy or ferritin levels and RLS in SCA3/MJD patients.

Serum concentrations of NSE and S100B in spinocerebellar ataxia type 3/Machado-Joseph disease.

OBJECTIVE: To determine the neuronal damage or loss and gliosis at the cellular level in spinocerebellar ataxia type 3/Machado-Joseph disease(SCA3/MJD), and evaluate the potential use of neuron-specific enolase (NSE) and protein S 100 B(S100B) serum concentrations as biochemical markers. METHODS: Serum concentrations of NSE and S100B were measured in 102 SCA3/MJD patients and 100 healthy subjects matched by sex and age. The correlations between both markers and age, age of onset, disease duration, CAG repeat size, scores of international cooperative ataxia rating scale(ICARS), and scale for the assessment and rating of ataxia(SARA) were analyzed. RESULTS: Compared with the healthy controls, patients with SCA3/MJD had higher NSE serum concentrations [(6.95 ± 2.83)ng/mL vs (4.83 ± 1.70) ng/mL, P<0.05] and higher S100B serum concentrations [(0.07 ± 0.06) ng/mL vs (0.05 ± 0.02) ng/mL, P<0.05]. In the SCA3/MJD patients group, NSE levels presented a positive correlation with age, disease duration, ICARS scores and SARA scores, whereas S100B levels did not correlate with age, age of onset, disease duration, ICARS scores and SARA scores. CAG repeat size did not correlate with the NSE levels and S100B levels in different age groups of SCA3/MJD patients. CONCLUSION: Serum NSE might be a useful marker to monitor disease progression and represent the degree of severity of a certain disease. Elevated S100B serum concentrations in patients compared to healthy controls may suggest an application of this protein as a peripheral marker of brain impairment in SCA3/MJD.