Association of S100B polymorphisms and serum S100B with risk of ischemic stroke in a Chinese population

S100B gene polymorphisms are associated with the S100B level and Alzheimer's disease risk by altering the miRNA binding capacity

To examine the role of S100B in genetic susceptibility to Alzheimer’s disease (AD), we conducted a case-control study to analyze four polymorphism loci (rs2839364, rs1051169, rs2300403, and rs9722) of the S100B gene and AD risk. We found an independent increased risk of AD in ApoE ε4(-) subjects carrying the rs9722 AA-genotype (OR = 2.622, 95% CI = 1.399–4.915, P = 0.003). Further investigation revealed the serum S100B levels to be lower in rs9722 GG carriers than in rs9722 AA carriers (P = 0.003). We identified three miRNAs (miR-340-3p, miR-593-3p, miR-6827-3p) in which the seed match region covered locus rs9722. Luciferase assays indicated that the rs9722 G allele has a higher binding affinity to miR-6827-3p than the rs9722 A allele, leading to a significantly decreased fluorescence intensity. Subsequent western blot analysis showed that the S100B protein level of SH-SY5Y cells, which carry the rs9722 G allele, decreased significantly following miR-6827-3p stimulation (P = 0.009). The present study suggests that the rs9722 polymorphism may upregulate the expression of S100B by altering the miRNA binding capacity and may thus increase the AD risk. This finding would be of great help for the early diagnosis of AD.

Safety and efficacy of remote ischemic postconditioning after thrombolysis in patients with stroke

OBJECTIVE

To determine the effect of remote ischemic postconditioning (RIPC) on patients with acute ischemic stroke (AIS) undergoing IV thrombolysis (IVT).

METHODS

A single-center randomized controlled trial was performed with patients with AIS receiving IVT. Patients in the RIPC group were administered RIPC treatment (after IVT) during hospitalization. The primary endpoint was a score of 0 or 1 on the modified Rankin scale (mRS) at day 90. The safety, tolerability, and neuroprotection biomarkers associated with RIPC were also evaluated.

RESULTS

We collected data from both the RIPC group (n = 34) and the control group (n = 34). The average duration of hospitalization was 11.2 days. There was no significant difference between 2 groups at admission for the NIH Stroke Scale score (p = 0.364) or occur-to-treatment time (p = 0.889). Favorable recovery (mRS score 0-1) at 3 months was obtained in 71.9% of patients in the RIPC group vs 50.0% in the control group (adjusted odds ratio 9.85, 95% confidence interval 1.54-63.16; p = 0.016). We further found significantly lower plasma S100-β (p = 0.007) and higher vascular endothelial growth factor (p = 0.003) levels in the RIPC group than in the control group.

CONCLUSIONS

Repeated RIPC combined with IVT can significantly facilitate recovery of nerve function and improve clinical prognosis of patients with AIS.

CLINICALTRIALSGOV IDENTIFIER

NCT03218293.

CLASSIFICATION OF EVIDENCE

This study provides Class IV evidence that RIPC after tissue plasminogen activator treatment of AIS significantly increases the proportion of patients with an MRS score of 0 or 1 at 90 days.

Cytokine Registry In Stroke Patients (CRISP): Protocol of a prospective observational study

Inflammation is an important pathophysiological process after an acute stroke (AS). Pro- and anti-inflammatory molecules (cytokines and interleukins) are the key players during this mechanism. Emerging evidence indicate that these molecules can serve as biomarkers of stroke progression and outcome and as novel therapeutics agents. The aim of this study is to explore the temporal changes in these molecules and validate them as biomarker of AS progression and neurological outcome.The "Cytokine Registry In Stroke Patients (CRISP)" is a prospective cohort study of 600 AS patients presenting to the tertiary hospital with-in 24 h of the onset of symptoms. Plasma cytokines and interleukins will be collected at admission and 24 h after and will be measured using enzyme-linked immunosorbent assay (ELISA) to evaluate the difference in their variation among different gender, race and ethnicity and their association with various neurological outcomes. The primary exposures are biological sex (male, female) and race/ethnicity. Confounding variables include age, vascular risk factors, infarct size, stroke onset to presentation time, and identified stroke etiologies. Matched controls will be used for the comparison and evaluation of the difference among gender and race/ethnicities.CRISP is a prospective observational study that investigates the role and relationship of molecular biomarkers identifying specific and relevant targets pertinent for monitoring the progression and outcome in AS patients.Trial Registration: The study is registered on ClinicalTrial.gov: https://clinicaltrials.gov/ (NCT03297827).

Association of S100B 3'UTR polymorphism with risk of chronic heart failure in a Chinese Han population

To study the correlation between single nucleotide polymorphism (SNP) of the 3' untranslated region (UTR) rs9722 locus in S100B and the risk of chronic heart failure (CHF), plasma levels of S100B protein as well as has-miR-340-3p in a Chinese Han population.A total of 215 patients with CHF (124 ischemic cardiomyopathy (ICM) and 91 dilated cardiomyopathy (DCM)) and 215 healthy controls were recruited to analyze the S100B rs9722 genotype by Sanger sequencing. The levels of hsa-miR-340-3p in the plasma were detected by RT-PCR, and S100B levels were detected by ELISA.The risk of CHF in S100B rs9722 locus T allele carriers was 4.24 times higher than that in those with the C allele (95% CI: 2.84-6.33, P < .001). The association of S100B rs9722 locus SNP with ICM and DCM risk was not affected by factors such as age, gender, and body mass index (BMI). The levels of plasma S100B and hsa-miR-340-3p in patients with ICM and DCM were significantly higher than those in the control group (P < .001). There was no significant difference in plasma S100B levels between patients with ICM and DCM (P > .05). Among ICM, DCM, and control subjects, TT genotype carriers had the highest levels of plasma S100B and hsa-miR-340-3p, followed by the CT genotype and TT genotype, and the difference was statistically significant (P < .05). Plasma hsa-miR-340-3p levels were positively correlated with S100B levels in the control subjects and patients with ICM and DCM.The S100B rs9722 locus SNP is associated with CHF risk in a Chinese Han population.

S100B single nucleotide polymorphisms exhibit sex-specific associations with chronic pain in sickle cell disease in a largely African-American cohort

BACKGROUND

Pain in sickle cell disease (SCD) is severe and multifaceted resulting in significant differences in its frequency and intensity among individuals. In this study, we examined the influence of S100B gene single nucleotide polymorphisms (SNP) on acute and chronic pain variability in SCD.

METHODS

Composite pain index (CPI) scores captured chronic pain. Painful crisis related emergency care utilization recorded acute pain incidence. Genotyping was performed using MassARRAY iPLEX platform.

RESULTS

Regression analysis revealed associations of increased CPI with rs9722 A allele in additive (p = 0.005) and dominant (p = 0.005) models. Rs1051169 G allele on the other hand was associated with decreased CPI in additive (p = 0.001), and dominant (p = 0.005) models. Sex-specific analysis found that these associations were significant in females but not males in this cohort. Linkage analysis identified two haploblocks. Block 1 (rs9983698-rs9722) haplotype T-A was associated with increased CPI (p = 0.002) while block 2 (rs1051169-rs11911834) haplotype G-G was associated with decreased CPI (p = 0.001). Both haplotypic associations were only significant in females. No association of S100B SNPs with utilization reached statistical significance.

CONCLUSIONS

S100B SNPs and haplotypes are associated with chronic pain in female, but not male, patients with SCD, implicating a potential role of S100B polymorphism in SCD pain heterogeneity in a sex-dependent manner.

The elevation of S100B and downregulation of circulating miR-602 in the sera of ischemic stroke (IS) patients: the emergence of novel diagnostic and prognostic markers

Ischemic stroke (IS) is a major cause of mortality and disability. However, no reliable prognostic or diagnostic biomarker has been utilized to date. Here, we have evaluated the serum S100B concentration and miR-602 expression as potential biomarkers for IS. Fifty-two IS patients and 52 age- and sex-matched healthy volunteers were enrolled. Blood samples were collected from all patients at the time of admission, 24 and 48 h later, at the time of discharge, and 3 months later. Real-time (RT) PCR was used to measure the serum level of miR602. We also measured the serum concentration of S100B using ELISA. As compared with healthy subjects, IS patients had a higher level of serum S100B and lower serum miR-602. ROC curve analyses revealed that miR-602 (AUC = 0.8168; P < 0.0001) and S100B (AUC = 0.8699; P < 0.0001) had acceptable ability to differentiate between IS patients from healthy subjects. Furthermore, serum S100B was a reliable predictor of the survival outcome at 3 months (P = 0.021). The expression of miR-602 was significantly higher in patients with bigger NIHSS scores. The lower levels of miR-602 and higher concentration of S100B in the sera of IS patients could be associated with clinically significant diagnostic utilities. S100B could be also introduced as a reliable prognostic marker for stroke and implemented in future research.

A functional polymorphism in the promoter of TUG1 is associated with an increased risk of ischaemic stroke

Taurine‐upregulated gene 1 (TUG1), a kind of long non‐coding RNAs (lncRNAs), was up‐regulated in ischaemic stroke (IS) with the function of promoting neuron apoptosis. In this study, we aimed to investigate the association of TUG1 polymorphisms with IS risk. The TUG1 polymorphisms were genotyped using a custom‐by‐design 48‐Plex SNPscan kit. The promoter activity was measured using the dual luciferase reporter assay. Relative expression of TUG1 in IS patients was analysed using quantitative PCR and the binding of TUG1rs2240183 polymorphism to transcription factor was analysed using chromatin immunoprecipitation (ChIP) assay. The rs2240183 CT/CC genotypes and C allele in the promoter of TUG1 were associated with an increased risk of IS (CT/CC vs. TT: adjusted OR = 1.70, 95% CI, 1.16‐2.49, P = 0.006; C vs. T: adjusted OR = 1.47, 95% CI, 1.12‐1.93, P = 0.005). Logistic regression analysis showed that the rs2240183 was a risk factor of IS besides TC, TG, HDL‐C, LDL‐C, VLDL‐C, Apo‐A1, Apo‐B and NEFA. Further functional analysis revealed that the TUG1rs2240183 C allele exhibited higher transcriptional activity and TUG1 expression levels (P < 0.01). The ChIP assay showed that the rs2240183 C allele binds to transcriptional factor GATA‐1. These findings indicate that the rs2240183 C allele was associated with a higher risk of IS possibly by binding to GATA‐1 and elevating TUG1 levels.

A functional variant rs12904 in the miR-200c binding site was associated with a decreased risk of ischemic stroke

Genome-wide association study (GWAS) identified chromosome 12p13 rs12425791 and rs11833579 as susceptibility loci of ischemic stroke (IS) in a European population. However, conflicting results were obtained in subsequent replication analysis. miR-200c, located on chromosome 12p13, was found to have a neuroprotective effect on ischemia. Our aim of this study was to investigate the association of the rs12425791, rs11833579 and rs12904 in the binding site of miR-200c with the risk of IS. The rs12425791, rs11833579, and rs12904 were genotyped using a TaqMan allelic discrimination assay. The results were verified by Sanger sequencing. We found that the rs12904 AG/GG genotypes and G allele were associated with a decreased risk of IS (AG/GG vs. AA: adjusted OR = 0.64; 95% CI, 0.44-0.95; G vs. A: adjusted OR = 0.65; 95% CI, 0.46-0.93). The combined genotypes of the rs11833579AG/AA and rs12904AG/GG were also associated with a reduced risk of IS (OR = 0.65; 95% CI, 0.46-0.93). These findings suggest that the rs12904 may have a jointly protective effect against the risk of IS.

Dual Functions of Microglia in Ischemic Stroke

Ischemic stroke is a leading cause of morbidity and mortality worldwide. Resident microglia are the principal immune cells of the brain, and the first to respond to the pathophysiological changes induced by ischemic stroke. Traditionally, it has been thought that microglial activation is deleterious in ischemic stroke, and therapies to suppress it have been intensively explored. However, increasing evidence suggests that microglial activation is also critical for neurogenesis, angiogenesis, and synaptic remodeling, thereby promoting functional recovery after cerebral ischemia. Here, we comprehensively review the dual role of microglia during the different phases of ischemic stroke, and the possible mechanisms controlling the post-ischemic activity of microglia. In addition, we discuss the dynamic interactions between microglia and other cells, such as neurons, astrocytes, oligodendrocytes, and endothelial cells within the brain parenchyma and the neurovascular unit.

Thromboxane A synthase 1 gene expression and promotor haplotypes are associated with risk of large artery-atherosclerosis stroke in Iranian population

Large artery atherosclerosis (LAA) is known as an important cause of ischemic stroke (IS), which is a multifactorial disorder. Many candidate genes have been proposed for IS like (TBXAS1) that plays a significant role in LAA stroke pathogenesis. This is the first study on the evaluation of the association of the five single-nucleotide polymorphisms (SNPs) in TBXAS1 promoter region and the level of TBXAS1 transcript with large-artery atherosclerosis stroke. Five SNPs in TBXAS1 genes were investigated in 248 patients with large-artery atherosclerosis stroke and 199 healthy controls in Iranian population in this case-control study through using the high-resolution melting assay. In addition, the relationships between the selected SNPs with alteration of TBXAS1 gene expressions were investigated in terms of blood platelets through the reverse transcription-quantitative polymerase chain reaction. Multivariate logistic analysis with adjustments indicated that rs10256282CC, rs10237429CC, and rs4590360GG genotypes were associated with large-artery atherosclerosis stroke (adjusted odds ratio = 2.804, 2.872, and 2.432, respectively; P < 0.05, q < 0.05). Furthermore, the frequency of CACCG haplotype in the patients was greatly higher than that in the controls (OR = 1.424, 95% CI: 1.071-1.893, P = 0.014738). In addition, TBXAS1 expression was higher in patients compared to the controls (P = 0.021), and individuals with the homozygous mutated genotypes of these SNPs showed a higher expression level compared to other genotype (P < 0.05). In total, our findings indicate a significant association of TBXAS1 gene rs10256282CC, rs10237429CC, and rs4590360GG polymorphisms with large-artery atherosclerosis stroke susceptibility and the level of TBXAS1 expression, which was not previously reported in any population.