Lu Tang

Protective effects of resveratrol through the up-regulation of SIRT1 expression in the mutant hSOD1-G93A-bearing motor neuron-like cell culture model of amyotrophic lateral sclerosis

Resveratrol has recently been widely reported to be an age-delaying and neuroprotective compound, and it appears to produce these benefits by activating silent mating type information regulation 2 homolog 1 (SIRT1). However, the role that SIRT1 activation plays in the pathogenesis of amyotrophic lateral sclerosis (ALS) remains unclear. In the present study, SIRT1 expression was found to be much lower in the mutant hSOD1G93A-bearing VSC4.1 cells compared to hSOD1wt cells when both were cultured in low-serum medium, indicating the involvement of SIRT1 activation defects in the pathogenesis of ALS under energetic stress. Further investigation revealed that a 24-h treatment with 0.5-20μM resveratrol had a dose-dependent protective effect on this ALS cell model, and the effects of resveratrol on increasing cell viability, preventing cell apoptosis and elevating cellular ATP levels through promoting mitochondria biogenesis were blocked by SIRT1 inhibition. This further demonstrated a role for SIRT1 activation in the protection of neuronal cells from degeneration. These findings suggest that resveratrol can protect the ALS cell model from mutant SOD1-mediated toxicity through up-regulating the expression of SIRT1, which represents a potential therapeutic target for preventing the motor neuron degeneration in ALS patients.

ATXN2 CAG repeat expansions increase the risk for Chinese patients with amyotrophic lateral sclerosis

Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disorder with unclear etiology. Recently, intermediate CAG repeat expansions in ATXN2, the gene responsible for spinocerebellar ataxia type 2 (SCA2), have been identified as a possible genetic risk factor for ALS. In this study, we analyzed the ATXN2 CAG repeat length in Chinese patients with ALS to evaluate the relationship between the genotype and phenotype. We studied 1,067 patients with ALS and 506 controls from mainland China (excluding Tibet). We collected clinical data and analyzed fluorescent PCR products to assess ATXN2 CAG repeat length in all of the samples. We observed that intermediate CAG repeat expansions in ATXN2 (CAG repeat length >30) were associated with ALS (p = 0.004). There was no significant difference in clinical characteristics between the groups with and without intermediate CAG repeat expansions in ATXN2. Our data indicate that, for ALS patients from mainland China, intermediate CAG repeat expansions in ATXN2 increase the risk of ALS but have no effect on disease phenotype.

Natural history and clinical features of sporadic amyotrophic lateral sclerosis in China

Objectives To describe the natural history and clinical features of sporadic amyotrophic lateral sclerosis (ALS) in Chinese patients, and to report data on the prognostic factors for survival. Methods All patients referred to our ALS centre between 2003 and 2012 were followed up every 3 months. Survival and tracheotomy were predefined as primary outcome measures. Group differences were analysed using parametric and non-parametric tests as appropriate. Survival was analysed using the Kaplan-Meier method and Cox regression analysis. Results Of the 1624 patients with ALS, 75.1% had limb-onset, 14.0% had bulbar-onset, 7.8% had flail-arm syndrome (FAS), 2.6% had progressive muscular atrophy and 0.5% had primary lateral sclerosis. The male:female ratio was 1.7:1, and the mean age at onset was 49.8 years. The median diagnostic delay was 14 months, and the median survival time after symptom onset was 71 months. Male gender, older age at symptom onset, lower body mass index, shorter diagnostic delay, bulbar-onset ALS phenotype, higher Airlie House category at presentation, rural place of residence, use of traditional Chinese medicine and a history of contact with pesticides were associated with poorer survival, whereas female gender or an FAS phenotype may have a better prognosis. Conclusions The clinical characteristics and outcomes of Chinese patients with sporadic ALS were different compared with patients from other countries. Compared with other studies, the age at onset of Chinese patients was earlier, the percentage of bulbar-onset ALS was lower and the prognosis was better. This study substantially advances the understanding of the clinical features and epidemiology of this rare disease.

C9orf72 hexanucleotide repeat expansions in Chinese sporadic amyotrophic lateral sclerosis.

A hexanucleotide repeat expansion (HRE) in the C9orf72 gene has been identified as the most common mutation in amyotrophic lateral sclerosis (ALS) among Caucasian populations. We sought to comprehensively evaluate genetic and epigenetic variants of C9orf72 and the contribution of the HRE in Chinese ALS cases. We performed fragment-length and repeat-primed polymerase chain reaction to determine GGGGCC copy number and expansion within the C9orf72 gene in 1092 sporadic ALS (sALS) and 1062 controls from China. We performed haplotype analysis of 23 single-nucleotide polymorphisms within and surrounding C9orf72. The C9orf72 HRE was found in 3 sALS patients (0.3%) but not in control subjects (p = 0.25). For 2 of the cases with the HRE, genotypes of 8 single-nucleotide polymorphisms flanking the HRE were inconsistent with the haplotype reported to be strongly associated with ALS in Caucasian populations. For these 2 individuals, we found hypermethylation of the CpG island upstream of the repeat, an observation not detected in other sALS patients (p < 10(-8)) or controls. The detailed analysis of the C9orf72 locus in a large cohort of Chinese samples provides robust evidence that may not be consistent with a single Caucasian founder event. Both the Caucasian and Chinese haplotypes associated with HRE were highly associated with repeat lengths >8 repeats implying that both haplotypes may confer instability of repeat length.

C9orf72 repeat expansions are not detected in Chinese patients with familial ALS

ISSN 2167-8421 print/ISSN 2167-9223 online

Optineurin mutations in patients with sporadic amyotrophic lateral sclerosis in China

Abstract The purpose of this study was to assess the frequency of optineurin (OPTN) mutation in amyotrophic lateral sclerosis (ALS) patients from mainland China, as well as to characterize the relationship between OPTN mutation and clinical phenotypes. We examined the coding region of OPTN in 511 unrelated Chinese sporadic ALS (SALS) subjects and 204 healthy controls using a PCR direct sequencing strategy. Nine OPTN variants were identified, of which four were novel missense mutations: c.407C > T (p.A136V), c.1184A > G (p.K395R), c.1352T > C (p.I451T), and c.1546G > C (p.E516Q) (all heterozygous). The remaining five variants were already present in single nucleotide polymorphism databases. Patients with OPTN mutations were characterized by spinal onset, although they showed differences in disease progression. In conclusion, this study provides a genetic epidemiological characterization of OPTN mutations in Chinese patients, and our results are consistent with the proposition that such mutations are common in Asian populations.

Six SQSTM1 mutations in a Chinese amyotrophic lateral sclerosis cohort

The purpose of this study was to identify SQSTM1 gene mutations, estimate survival based on the progression rate of the revised amyotrophic lateral sclerosis functional rating scale (ALSFRS-R) score (ΔFS), and characterize the relationships between SQSTM1 mutations and clinical phenotypes in Chinese ALS patients. We sequenced the SQSTM1 gene in 35 familial ALS patients, 436 sporadic ALS patients, and 384 healthy controls. SQSTM1 gene mutations were screened with PCR and direct sequencing; the correlations between genotype and phenotype and the progressive ALSFRS-R ratio were analyzed. Results revealed six heterozygous missense mutations in 471 ALS patients: c.241 G> A (p.E81K), c.717 C> A (p.N239K), c.889 G> A (p.G297S), c.1116 G> C (p.E372D), c.1162 C> T (p.P388S) and c.1175 C> T (p.P392 L). The gender ratio was 1:1, and the limb was the site of disease onset in mutation-positive patients. Notably, the ΔFS analysis revealed that the risk of death or tracheostomy was significantly increased in SQSTM1 mutation carriers (p < 0.05). In conclusion, E81K, N239K, G297S, E372D, P388S and P392 L were detected in the PB1, TRAF6, PEST and UBA domains, which are important to p62 function and prone to ALS. The incidence of ALS caused by the SQSTM1 mutation has increased from 30 to 35 worldwide.

ARHGEF28 gene exon 6/intron 6 junction mutations in Chinese amyotrophic lateral sclerosis cohort

Abstract It was reported that the intron 6, + 1 del G (GT>TT) mutation of the ARHGEF28 gene generates a shortened protein that might be related to amyotrophic lateral sclerosis (ALS). We sequenced this mutation in 25 familial ALS (FALS), 357 sporadic ALS (SALS) patients, and 442 healthy control subjects. We found just two SALS patients exhibited the mutation so that the incidence of this mutation was 0.52% (2/382) of all the ALS patients. The clinical features of the mutation-positive patients were quite different from the case reported in a previous study. These characteristics differed in terms of gender, site of onset, cognitive function, and family history.

Long-Term Use of Riluzole Could Improve the Prognosis of Sporadic Amyotrophic Lateral Sclerosis Patients: A Real-World Cohort Study in China

Objectives: To investigate the effectiveness of riluzole in a long-term follow-up of cohort with sporadic amyotrophic lateral sclerosis (ALS) in a real-world study. Methods: Patients with ALS between 2007 and 2013 were followed up every 3 months. Survival and tracheotomy were predefined as primary outcome measures. The cumulative defined daily dose (cDDD) of riluzole was estimated. The patients in the riluzole group were classified into 1 of 3 subgroups according to the cDDD quartiles. Survival was analyzed using Kaplan–Meier and Cox regression analysis. Results: Of the 1,540 ALS patients, 415 (26.9%) used riluzole, and the remainder did not. In the riluzole group, the age at onset was greater (p = 0.016), the diagnostic delay was shorter (p < 0.0005), the body mass index (BMI) was higher (p < 0.0005), and the scores for both the functional rating scale (FRS) and the revised FRS (FRS-R) were higher (both p < 0.0005) than those of the control group. The median cDDD of riluzole was 28 (2,800 mg). Although Kaplan–Meier analysis did not reveal a significant difference between the two groups (p = 0.780), it showed that the prognosis of the beyond quartile 3 subgroup [cDDD ≥ 168 (16,800 mg)] was significantly better than that of the other groups [adjusted HR 0.488 (0.320–0.746), p = 0.001]. Conclusion: In China, older ALS patients and patients who had a higher BMI, shorter diagnostic delay, and higher FRS or FRS-R scores were more likely to use riluzole. Long-term use of riluzole was associated with a better prognosis for ALS patients, whereas short-term use had little effect on survival.

The single-nucleotide polymorphism rs6690993 in FGGY is not associated with amyotrophic lateral sclerosisin a large Chinese cohort

The single-nucleotide polymorphisms (SNPs) rs6700125 and rs6690993 in FGGY (FLJ10986) were recently reported to be a susceptibility factor for sporadic amyotrophic lateral sclerosis (SALS) in Caucasian populations in genome-wide association studies. However, no such association was observed in other independent genome-wide association studies or replication studies in a European cohort or 2 small sample sizes of Chinese patients. We performed a large case-control study in a cohort consisting of 963 SALS cases and 1039 control subjects to examine the association between the 2 reported SNPs in FGGY and amyotrophic lateral sclerosisin Chinese patients. Our results did not find the SNP rs6690993 in FGGY is associated with Chinese SALS and cannot confirm that this FGGY SNP modulates the risk for SALS in the Chinese population.