Promoter hypomethylation of microRNA223 gene is associated with atherosclerotic cerebral infarction.

BACKGROUND AND AIMS: microRNA223 (miR-223) plays an important role in the development of atherosclerosis and ischemic stroke. It is involved in regulation of multiple physiological and pathophysiological processes such as cholesterol metabolism, endothelial cell (EC) function, and thrombosis. Here we investigated the role of methylation regulation of MIR-223 promoter region in atherosclerotic cerebral infarction (ACI) patients. METHODS: A total of 23 patients with ACI and 32 healthy individuals were recruited. We performed bisulfite sequencing PCR and real-time PCR to detect methylation levels of MIR-223 promoter region and miR-223, respectively, in genomic DNA isolated from peripheral blood leukocytes. RESULTS: Mean methylation levels of a total of nine CpGs of MIR-223 promoter were significantly lower in ACI patients than in healthy individuals (p < 0.01), and were also significantly lower in individuals with carotid atherosclerosis than those without carotid atherosclerosis (p < 0.05). Meanwhile, miR-223 expression in leukocytes was significantly higher in ACI patients than in healthy individuals (p < 0.05). miR-223 level was negatively correlated with mean methylation levels of MIR-223 promoter (r = -0.4451, p < 0.01). The methylation level of MIR-223 promoter revealed a positive correlation with the circulating total cholesterol level (r = 0.318, p = 0.019). CONCLUSIONS: Hypomethylation of MIR-223 promoter is associated with atherosclerotic cerebral infarction.

Correlation of Plasma Vascular Endothelial Growth Factor and Endostatin Levels with Symptomatic Intra- and Extracranial Atherosclerotic Stenosis in a Chinese Han Population.

BACKGROUND: Symptomatic intracranial atherosclerotic stenosis (ICAS) and extracranial atherosclerotic stenosis (ECAS) are different in many aspects. Here, we explored the association between the location or severity of atherosclerotic stenosis and pro- or antiangiogenic factors, specifically vascular endothelial growth factor (VEGF) and endostatin (ES). METHODS: We evaluated 198 consecutive patients with acute ischemia stroke: 132 with large-artery atherosclerosis (LAA) and 66 with small-artery occlusion (small-vessel occlusion). The LAA group was subclassified into 102 patients with ICAS and 30 with ECAS. Independent associations of VEGF, ES levels, and VEGF/ES ratio with the location of cerebral stenosis and the severity or short-term prognosis (14th day modified Rankin Scale) of ICAS were evaluated. RESULTS: Plasma concentrations of VEGF and ES were lower (P < .05) in ICAS (38.07, 32.76-46.28 pg/mL and 58.95, 55.04-59.77 ng/mL) than those in ECAS (45.00, 34.30-83.34 pg/mL and 140.74, 85.63-231.21 ng/mL). Logistic regression analysis showed that VEGF concentrations and dyslipidemia were independently associated with ICAS, with odds ratios of .987 [95% CI = (.976, .998)] and .265 [95% CI = (.103, .792)], respectively. Moreover, plasmatic VEGF levels increased gradually along with the severity of ICAS (P = .003), and lower levels of ES (P = .040) or a higher VEGF/ES ratio (P = .048) were related to unfavorable short-term prognosis of ICAS. CONCLUSION: Lower VEGF levels are associated with the presence of symptomatic ICAS, but not with ECAS. Furthermore, the severity of ICAS is positively correlated with the levels of VEGF, and lower ES levels or a predominance of VEGF over ES are predictors of poor short-term prognosis of ICAS.

Detection of platelet microRNA expression in patients with diabetes mellitus with or without ischemic stroke.

AIMS: The objective of this study was to investigate the role of plasma and platelet microRNAs in the occurrence of ischemic stroke in patients with diabetes mellitus. METHODS: miR-223, miR-146a, miR-495, and miR-107 expression in the plasma and platelets, blood glucose concentration, and platelet activation rate were measured in patients with diabetes mellitus and ischemic stroke, diabetes mellitus only, ischemic stroke only, and healthy controls. Platelet activity was measured by flow cytometric measurement of P-selectin expression, while miRNA was measured by real-time PCR. RESULTS: The expressions of platelet and plasma miR-223 and miR-146a were significantly downregulated in patients with ischemic stroke and diabetes mellitus or diabetes mellitus only, but not in patients with ischemic stroke only compared to healthy controls. The expressions of platelet and plasma miR-495 and miR-107 showed no significant differences among these four groups. The expression of platelet miR-223 and miR-146a significantly correlated with plasma miR-223 and miR-146a levels, blood glucose concentration, and platelet activation rate. CONCLUSIONS: Hyperglycemia may downregulate the expressions of miR-223 and miR-146a, leading to subsequent platelet activation in patients with diabetes mellitus. Low platelet and plasma miR-223 and miR-146a expression is a risk factor for ischemic stroke in Chinese diabetes mellitus patients.

Association of BSG genetic polymorphisms with atherosclerotic cerebral infarction in the Han Chinese population.

The Basigin (BSG, also known as CD147/extracellular matrix metalloproteinase inducer) belongs to the immunoglobulin superfamily (IgSF). It is a cellular receptor for cyclophilin A (CypA), and is originally known as tumor cell collagenase stimulatory factor (TCSF), which could abundantly expressed on the surface of tumor cells, haematopoietic, monocytes, epithelial endothelial cells and smooth muscle cells. Accumulating evidence showed that BSG played an important role in stimulating the secretion of matrix metalloproteinases (MMPs), which has been reported to be involved in the development of atherosclerosis. Since atherosclerosis is an important risk factor for atherosclerotic cerebral infarction (ACI), we speculate that BSG genetic polymorphisms may influence formation of atherosclerosis and then development of ACI. This study aimed to detect the potential association of the single nucleotide polymorphisms (SNP, -631 G > T, -318 G > C, 10141 G > A and 10826 G > A) of BSG gene in Hunan Han Chinese population with ACI. We genotyped 199 ACI patients and 188 matched healthy controls for the four BSG SNP by method of matrix-assisted laser desorption/ionization-time-offlight mass spectrometry (MALDI-TOF MS). Our results suggested that all the polymorphisms were observed in the subjects from Changsha area of Hunan Province. However, no significant difference was observed between the distribution of these SNP in cases and controls. Therefore, we speculate that BSG genetic polymorphisms might not be an important factor in the development of ACI in our Chinese Han population.

A functional polymorphism at miR-491-5p binding site in the 3'-UTR of MMP-9 gene confers increased risk for atherosclerotic cerebral infarction in a Chinese population.

BACKGROUND: and purpose: Matrix metalloproteinases 9 (MMP-9) has been reported to play a critical role in the pathophysiology of atherosclerotic cerebral infarction (ACI). Here we assessed association of MMP-9 polymorphisms with ACI susceptibility and the function of SNPs through microRNA mediated regulation. METHODS: Genotyping was performed using MALDI-TOF mass spectrometry. Reporter gene plasmids with the MMP-9 3'UTR carrying either the mutant or the wild-type MMP-9 allele were constructed. Also, we constructed pcDNA-3.1-miR-491-5p recombinant plasmid, which transiently co-transfected human umbilical vein endothelial cells (HUVEC) with the reporter plasmids. Reporter plasmids, miR-491-5p mimics and inhibitor were transfected into HUVE cells line by lipofectamine. MMP-9 mRNA expression in HUVEC was detected by RT-PCR and protein level by ELISA. RESULTS: The rs1802908 and rs2664517 polymorphisms were not observed in all subjects from Hunan Han Chinese. No significant difference in genotype distribution of rs20544 and rs9509 between cases and controls were observed (p＞0.05). The rs1056628CC genotype had a significantly increased risk for ACI as compared with carries of the rs1056628 A allele (total χ(2) = 12.041, P = 0.002). Reporter gene assay revealed that the rs1056628 A allele showed lower reporter activity than the rs1056628C allele. Hsa-miR-491-5p had effect on modulation of MMP-9 gene in vitro. The rs1056628 A→C variant in the 3'-UTR of the MMP-9 increased MMP-9 protein expression in cultured HUVECs. CONCLUSIONS: Our data suggested that the rs1056629A→C variation contributes to an increased risk of ACI by increasing MMP-9 expression through affecting binding of miR-491 to the polymorphic site in the 3'-UTR of MMP-9.