急性缺血性脑卒中患者外周血白细胞miR-335基因启动子甲基化状态及意义

Relationship between acute ischemic stroke and miR-335 gene promoter methylation of peripheral blood leucocyte in patients

目的探讨急性缺血性脑卒中(AIS)患者外周血白细胞microRNA-335(miR-335)基因启动子区甲基化状态及在发病中的意义。方法应用生物信息学分析并使用亚硫酸氢钠测序(BSP)法检测30例AIS患者及30例健康对照者外周血白细胞miR-335基因(MIR335)启动子区甲基化状态,比较并分析与卒中严重程度(NIHSS评分)和血浆miR-335水平的关系。结果生物信息学分析显示MIR335启动子区与Cp G岛区域重叠;AIS患者外周血白细胞中MIR335启动子区呈高甲基化水平,明显高于健康对照组(P<0.01);AIS患者MIR335甲基化水平与miR-335表达水平呈负相关(r=-0.72,P<0.01),与病情严重程度呈正相关(r=0.74,P<0.01)。结论 AIS患者外周血白细胞MIR335启动子区呈明显高甲基化状态,可能参与了脑卒中缺血后调控。

Aim To investigate the relationship between acute ischemic stroke （AIS） and miR-335 gene （MIR335） promoter methylation of peripheral blood leucocyte in patients. Methods The study included 30 AIS pa- tients and 30 age- and sex-comparable heahhy controls. Bioinformatics database analysis was used to describe the CpG is-land of MIR335 promoter region. The quantitative methylation level in the 33 CpG sites of the MIR335 promoter was measured by bisulfite sequencing PCR in each participant. Stroke severity was evaluated by the National Institutes of Health Stroke Scale （NIHSS）. Results Bioinformatic searches show that the fragment surrounding the transcription start site of MIR335/MEST exhibits a characteristic CpG island which overlaps with the promoter region. Compared with healthy controls, the levels of MIR335 promoter methylation were significantly higher in stroke patients （P〈0.01）. The level of MIR335 promoter methylation was negatively correlated to the level of plasma miR-335 （r =-0.72, P〈0.01 ）, and positively correlated to NIHSS （r= 0.74, P〈0.01 ）. Conclusion Ischemic stroke patients have higher MIR335 pro- moter methylation levels in the peripheral blood leucocyte than those in the controls. The study implies that hypermethylation of MIR335 promoter CpG island might be involved in ischemic stroke.