MiR-150-5p通过调控GP IIb/IIIa受体改善替罗非班疗效的机制研究

Platelet membrane receptor (glycoprotein IIb/IIIa, GP IIb/IIIa) is the ultimate co-receptor of platelet aggregation pathway. Tirofiban, as a GP IIb/IIIa blocker, is widely used in the treatment of cardiovascular and cerebrovascular diseases because of its rapid and strong effect. However, the phenomenon of tirofiban resistance exists in clinical practice and the mechanism has not been fully elucidated. There is no transcriptional regulation in the platelet for no nuclear, but there is miRNA mediated posttranscriptional regulation. We found that miR-150-5p can degradate the mRNA of GP IIb/IIIa, and there was low expression in patients with cerebral infarction. The expression of miR-150-5p was positively correlated with the Dicer enzyme. Therefore，we think that the high expression of GP IIb/IIIa and platelet aggregation mediated by miR-150-5p may be the important reasons of tirofiban resistance. In this study, the regulation of miR-150-5p by Dicer enzyme, the mechanism of GP IIb/IIIa expression and platelet aggregation regulated by miR-150-5p, and miR-150-5p’s intervention will be systematically studied at cellular, rat animal and clinical sample levels via in-vitro and in-vivo experimental techniques such as miR-150-5p Cell Transfection and Gene Knockout, etc. This study will provide a new idea for the prevention and treatment of tirofiban resistance.

GP IIb/IIIa是血小板聚集的最终共同受体，替罗非班作为GP IIb/IIIa阻断剂具有起效快作用强的特点，在临床上广泛使用。然而临床上存在替罗非班抵抗现象，且机制尚未完全阐明。血小板无细胞核，不存在转录水平调控，但存在miRNA介导的转录后调控。我们前期发现，miR-150-5p能降解GP IIb/IIIa的mRNA，并且在脑梗死患者中表达低，其表达与 Dicer酶正相关。我们认为，受Dicer酶调控，miR-150-5p介导的GP IIb/IIIa表达和血小板聚集，可能是替罗非班抵抗的重要原因。本研究将综合运用miR-150-5p细胞转染和基因敲除等实验技术，在细胞、动物及临床样本水平研究Dicer酶对miR-150-5p的调控，以及miR-150-5p调控GP IIb/IIIa表达和血小板聚集的机制，并开展脑梗死大鼠miR-150-5p干预研究，为替罗非班抵抗的防治提供新思路。

脑梗死是全世界第二位的死亡/残疾病因，规律服用抗血小板治疗药物后仍有复发，目前既缺乏急性脑梗死特异性诊断分子靶标，又缺乏脑梗死抗血小板治疗药物抵抗的分子靶点。本研究基于血清外泌体miRNA高通量测序，筛选急性脑梗死差异化血清外泌体miRNA，进行小样本和大样本RT-PCR验证。首先，我们探讨了急性脑梗死血清差异化表达miRNA及高靶向GP IIb/IIIa mRNA的miRNA表达水平，分析差异miRNA与GP IIb/IIIa阻断剂耐药的相关分子机制，证实miR-150-5p不是调控GP IIb/IIIa的关键分子机制。其次，我们探讨了血清血小板来源外泌体miRNA在急性脑梗死发生发展中的相关分子机制及调控功能，发现miR-23a-3p、miR-375-3p有望成为急性脑梗死诊断的新的生物标记物，miR-200a-3p有望成为急性脑梗死干预治疗的新分子靶点。最后，我们探讨了替罗非班治疗急性脑梗塞取栓患者的疗效和安全性，发现替罗非班治疗急性前循环脑梗塞取栓患者安全有效。