【罂粟摘要】MicroRNA-374通过激活PI3K/Akt通路抑制SP1对七氟醚预处理后大鼠心肌缺血-再灌注模型中的保护作用
MicroRNA-374通过激活PI3K/Akt通路抑制SP1对七氟醚预处理后大鼠心肌缺血-再灌注模型中的保护作用
贵州医科大学 高鸿教授课题组
译：安丽 编：佟睿 审：曹莹
缺血性心脏病是心血管疾病死亡的主要原因，而microRNAs (miRs)已被报道为心脏病的潜在治疗靶点。本研究旨在探讨microRNA (miR)-374通过磷脂酰肌醇3-激酶(PI3K)/Akt通路(PI3K/Akt通路)靶向转录因子SP1对七氟醚预处理大鼠心肌缺血再灌注损伤的影响。
SD大鼠随机分为假手术组、I/R组和七氟醚+I/R组(七氟醚预处理+I/R组)。采用生化检测、伊文思蓝-TTC染色、免疫组织化学和TUNEL染色检测生化指标、病理改变、SP1蛋白阳性表达和细胞凋亡率。RT-qPCR和Western blotting检测miR-374mRNA和Sp1、PI3K、HO-1、p53、诱导型一氧化氮合酶、c-fos、Akt/p-Akt和GSK-3β/p-GSK-3β的蛋白表达。心肌细胞用miR-374模拟物、miR-374抑制剂或siRNA-SP1处理。采用四甲基偶氮唑盐(MTT)法和流式细胞仪检测心肌细胞增殖、细胞周期分布和细胞凋亡。
与I/R组比较，七氟醚+I/R组血清超氧化物歧化酶、白细胞介素-10升高，丙二醛、乳酸脱氢酶、肌酸激酶、肿瘤坏死因子-α、白细胞介素-6、白细胞介素-10降低，梗死面积百分比、阳性表达率及细胞凋亡指数下降。Sp1、P53、iNOS、c-fos表达降低，PI3K、HO-1、Akt/p-Akt、GSK-3β/p-GSK-3β表达升高。随着miR374mRNA的上调和sp1的下调，sp1、p53、iNOS和c-fos的表达下降，G1期细胞比例和凋亡率下降，PI3K、HO-1、Akt/p-Akt、GSK-3β/p-GSK-3β表达增加。miR-374抑制剂组的结果与上述结果形成对比。
miR-374可通过激活PI3K/ Akt通路靶向SP1，减轻七氟醚预处理大鼠心肌I/R损伤。
MicroRNA-374 Exerts Protective Effects by Inhibiting SP1 Through Activating the PI3K/Akt Pathway in Rat Models of Myocardial Ischemia-Reperfusion After Sevoflurane Preconditioning
Background/Aims: Ischemic heart disease is a leading cause of death in cardiovascular diseases, and microRNAs (miRs) have been reported to be potential therapeutic targets in heart disease. Herein, this study aims to investigate the effects of microRNA (miR)-374 on myocardial ischemia-reperfusion (I/R) injury in rat models pretreated with sevoflurane by targeting SP1 through the PI3K/Akt pathway.
Methods: SD rats were grouped into sham, I/R and sevoflurane + I/R (sevoflurane preconditioning and I/R) groups. The biochemical indicators, pathological changes, positive expression of SP1 protein, and apoptosis rates were measured using biochemical detection, Evans blue-TTC staining, immunohistochemistry and TUNEL staining. RT-qPCR and Western blotting were used to investigate the expression of miR374 mRNA and the protein expression of SP1, PI3K, HO-1, p53, iNOS, c-fos, Akt/p-Akt, and GSK-3β/p-GSK-3β. Cardiomyocytes were treated with miR-374 mimics, miR-374 inhibitors, or siRNA-SP1. Cardiomyocyte proliferation and cycle distribution and apoptosis were studied by MTT and flow cytometry.
Results: Compared with the I/R group, in the sevoflurane + I/R group, serum SOD and IL-10 increased, while MDA, LDH, CK, TNF-α, IL-6 and IL-10 decreased, as did the percentage of infarct area, the positive rate of SP1 and the apoptosis index. The expression of SP1, p53, iNOS and c-fos decreased, and the miR-374 expression of PI3K, HO-1, Akt/p-Akt, GSK-3β/p-GSK-3β increased. With the upregulation of miR-374 and the downregulation of SP1, the expression of SP1, p53, iNOS and c-fos decreased, as did the proportion of cells in G1 phase and the apoptosis rate; the expression of PI3K, HO-1, Akt/pAkt, GSK-3β/p-GSK-3β increased. The results in the miR-374 inhibitor group contrasted with the above results.
Conclusion: The results indicated that miR-374 could alleviate myocardial I/R damage in rat models pretreated with sevoflurane by targeting SP1 by activating the PI3K/Akt pathway.