High serum uric acid levels are a protective factor against unfavourable neurological functional outcome in patients with ischaemic stroke.

Objective We aimed to evaluate the association between serum uric acid levels at the onset and prognostic outcome in patients with acute ischaemic stroke. Methods We retrospectively analysed the outcomes of 1166 patients with ischaemic stroke who were hospitalized in our centre during August 2008 to November 2012. Correlations of serum uric acid levels and prognostic outcomes were analysed. Results Men had higher serum uric acid levels and better neurological functional outcomes compared with women. There was a strong negative correlation between serum uric acid levels and unfavourable neurological functional outcomes. Generalized estimated equation analysis showed that a higher serum uric acid level (>237 µmol/L) was a protective factor for neurological functional outcome in male, but not female, patients. Among five trial of ORG 10172 in acute stroke treatment classification subtypes, only patients with the large-artery atherosclerosis subtype had a significant protective effect of serum uric acid levels on neurological outcome. Conclusions Our study shows that high serum uric acid levels are a significant protective factor in men and in the large-artery atherosclerosis subtype in patients with ischaemic stroke. This is helpful for determining the prognostic value of serum uric acid levels for neurological outcome of acute ischaemic stroke.

The association between the ring finger protein 213 (RNF213) polymorphisms and moyamoya disease susceptibility: a meta-analysis based on case-control studies.

A number of studies assessed the association of ring finger protein 213 (RNF213) gene polymorphisms with moyamoya disease (MMD), but the results were not entirely consistent. This meta-analysis was performed to explore the relationship between RNF213 polymorphisms and moyamoya disease in Asian population. A systematic search from the PubMed, MEDLINE, EMBASE, ISI web of science, CNKI, China CBM and WANFANG DATA databases was conducted to retrieve published studies until March 2015. Statistical analyses were performed using the STATA12.0 software. Fixed or random effects model, subgroup analysis, sensitivity analysis, and publication bias were used to improve the comprehensive analysis. Eight papers including 904 MMD patients and 2258 controls were recruited in the meta-analysis. rs112735431 was closely associated with the risk of MMD among Asian population in all genetic models (dominant model: OR 103.39, 95 % CI 52.25-204.55, P = 1.69e-40; recessive model: OR 16.45, 95 % CI 6.00-45.10, P = 5.33e-08; additive model: OR 61.49, 95 % CI 22.07-171.33, P = 3.32e-15), especially in the Japanese population. Subgroup analysis revealed highly statistically significant higher risk in the patients with family histories. Although another polymorphism rs148731719 showed no significant association with the MMD, rs138130613 was found to be related to the higher risk in Chinese population (dominant model: OR 8.34, 95 % CI 1.72-40.47, P = 0.008). Our meta-analysis strengthens RNF213 rs112735431 is closely associated with the increased risk of MMD in Japanese, and the screening combined with rs112735431 and rs138130613may improve the detection rate for MMD in China.

The single nucleotide polymorphism rs2208454 confers an increased risk for ischemic stroke: a case-control study.

AIM: A recent genome-wide association study identified a strong association of covert magnetic resonance imaging infarcts with the single nucleotide polymorphism (SNP) rs2208454. The aim of this study was to determine whether the rs2208454 polymorphism is associated with an increased risk for ischemic stroke (IS). METHODS: Ischemic stroke patients (n = 712) and control subjects (n = 774) from a southern Chinese Han population were included. The snapshot technique was used for genotype analysis. RESULTS: Compared with the GT+GG or GG genotype, the frequency of the TT genotype was significantly higher in IS than in controls. After adjusting for age, gender, family history of IS, hypertension history, and history of diabetes mellitus, a significant correlation between the TT genotype and IS persisted (TT vs. GT+GG: adjusted OR = 1.79, 95% CI: 1.16-2.77; TT vs. GG: adjusted OR = 1.88, 95% CI: 1.20-2.94). In subgroup analyses, SNP rs2208454 was significantly associated with large artery atherosclerosis (LAA) (TT vs. GG: adjusted OR = 2.16, 95% CI: 1.19-3.93), but failed to show significant association with small-artery occlusion or cardioembolism IS subtypes. CONCLUSIONS: Single nucleotide polymorphism rs2208454 confers an increased risk for IS in a southern Chinese Han population. When the IS subtype was examined, the effect of the SNP was restricted to LAA.

A conserved region in the 3' untranslated region of the human LIMK1 gene is critical for proper expression of LIMK1 at the post-transcriptional level.

LIM kinase 1 (LIMK1), a cytosolic serine/threonine kinase, regulates actin filament dynamics and reorganization and is involved in neuronal development and brain function. Abnormal expression of LIMK1 is associated with several neurological disorders. In this study, we performed a conservation analysis using Vector NTI (8.0) software. The dualluciferase reporter assay and real-time quantitative RT-PCR were used to assess the protein and mRNA levels of the reporter gene, respectively. We found that a region ranging from nt +884 to +966 in the human LIMK1 3' untranslated region (UTR) was highly conserved in the mouse Limk1 3' UTR and formed a structure containing several loops and stems. Luciferase assay showed that the relative luciferase activity of the mutated construct with the conserved region deleted, pGL4-hLIMK1-3U-M, in SH-SY5Y and HEK-293 cells was only ~60% of that of the wild-type construct pGL4-hLIMK1-3U, indicating that the conserved region is critical for the reporter gene expression. Real-time quantitative RT-PCR analysis demonstrated that the relative Luc2 mRNA levels in SH-SY5Y and HEK293 cells transfected with pGL4-hLIMK1-3U-M decreased to ~50% of that in cells transfected with pGL4-hLIMK1-3U, suggesting an important role of the conserved region in maintaining Luc2 mRNA stability. Our study suggests that the conserved region in the LIMK1 3' UTR is involved in regulating LIMK1 expression at the post-transcriptional level, which may help reveal the mechanism underlying the regulation of LIMK1 expression in the central nervous system and explore the relationship between the 3'-UTR mutant and neurological disorders.

Promoter analysis of mouse Scn3a gene and regulation of the promoter activity by GC box and CpG methylation.

Voltage-gated sodium channel α-subunit type III (Na(v)1.3) is mainly expressed in the central nervous system and is associated with neurological disorders. The expression of mouse Scn3a product (Na(v)1.3) mainly occurs in embryonic and early postnatal brain but not in adult brain. Here, we report for the first time the identification and characterization of the mouse Scn3a gene promoter region and regulation of the promoter activity by GC box and CpG methylation. Luciferase assay showed that the promoter region F1.2 (nt -1,049 to +157) had significantly higher activity in PC12 cells, comparing with that in SH-SY5Y cells and HEK293 cells. A stepwise 5' truncation of the promoter region found that the minimal functional promoter located within the region nt -168 to +157. Deletion of a GC box (nt -254 to -258) in the mouse Scn3a promoter decreased the promoter activity. CpG methylation of the F1.2 without the GC box completely repressed the promoter activity, suggesting that the GC box is a critical element in the CpG-methylated Scn3a promoter. These results suggest that the GC box and CpG methylation might play important roles in regulating mouse Scn3a gene expression.

Identification of the transcriptional promoters in the proximal regions of human microRNA genes.

To identify the transcriptional promoters in the proximal regions of human microRNA (miRNA) genes, we analyzed the 5' flanking regions of intergenic miRNAs and intronic miRNAs. With the TSSG program prediction, we found that the ratio of intronic-s miRNA genes with a least one promoter was significantly lower than those of intergenic miRNA genes and intronic-a miRNA genes. More than half of the miRNA genes have only one promoter and less than 20% of the miRNA genes have more than three promoters in the 5-kb upstream regions. All potential promoters are randomly distributed within these regions. Approximately 60% of the miRNA promoters have a TATA-like box, being significantly higher than that of all human promoters. Luciferase reporter assays showed that 22 of the 30 promoters drove gene expression in HEK-293 cells, indicating a high accuracy of the promoter prediction. This study lays a foundation for future investigation into the transcriptional regulatory mechanisms of human miRNA genes.

Experimental identification of microRNA targets on the 3' untranslated region of human FMR1 gene.

FMR1 gene plays an important role in the development of central nervous system. Down-regulation of the FMR1 expression leads to fragile X syndrome. MicroRNAs (miRNAs) can repress gene expression by base pairing with their mRNA targets. By computer programs analysis, five miRNAs: miR-19a, miR-19b, miR-142, miR-302b* and miR-323-3p potentially target to different sites on the FMR1 3' untranslated region (3' UTR), except that miR-19a and miR-19b share the same targeting site. To test whether these miRNAs repress reporter gene expression by interacting with the miRNA targets on the FMR1 3' UTR, we developed two chimeric constructs: one construct expressing a firefly luciferase with the FMR1 3' UTR or its miRNA target mutations and the other construct expressing a pre-miRNA fusing with GFP. Luciferase assay co-transfecting with the two constructs showed that the miRNAs, miR-19b, miR-302b* and miR-323-3p could repress gene expression in HEK-293 cells, suggesting a role of these miRNAs in the regulation of the FMR1 expression. The constructs used in this study can be widely used to identify the miRNA targets in any interested genes, which will greatly promote the current progress in understanding the biological function of miRNAs.