MicroRNA-155通过P2X7R激活NLRP3炎性小体促进ApoE^-/-小鼠颈动脉粥样硬化斑块的形成

MicroRNA-155 Activates the NLRP3 Inflammasome by Regulating the P2X7R in Carotid Atherosclerotic Plaques of ApoE^-/- Mice

摘要: 目的：探索在ApoE^−/−小鼠中，microRNA-155 (miR-155)调控NLRP3炎症小体参与其颈动脉粥样硬化(atherosclerosis, AS)斑块形成的可能机制，为预防和治疗AS提供理论基础。方法：36只6周龄的雄性ApoE^−/−小鼠随机分为6组(每组6只)：blank组、NC组、miR-155 mimic组、miR-155 inhibitor组、miR-155 mimic and NC组、miR-155 mimic and P2X7R(-)组。利用PCR技术检测小鼠颈动脉斑块中miR-155的表达水平，HE染色显示颈动脉内膜，利用western blot技术检测P2X7R、NLRP3炎症小体相关蛋白、IL-1β表达水平。结果：与NC组相比，miR-155 mimic组中miR-155表达、P2X7R、NLRP3炎症小体相关蛋白以及IL-1β表达的升高有显著的统计学意义(P < 0.05)，miR-155 inhibitor组则相反。miR-155 mimic and NC组与miR-155 mimic组中NLRP3炎症小体相关蛋白和IL-1β表达无明显差异，而miR-155 mimic and P2X7R(-)组的蛋白表达均明显减少(P < 0.05)。结论：在ApoE^−/−小鼠中，miR-155可能通过调控P2X7R，激活NLRP3炎症小体，增强炎症反应，从而促进AS斑块的形成和发展。

Abstract: Objective: To explore the possible mechanism of microRNA-155 (miR-155) involved in the regulation of NLRP3 inflammasome mediated carotid atherosclerotic plaque formation in ApoE^−/− mice, and to provide theoretical basis for the prevention and treatment of atherosclerosis. Methods: Thirty-six 6-week-old male ApoE^−/− mice were randomly divided into six groups (6 in each group): blank group, NC group, miR-155 mimic group, miR-155 inhibitor group, miR-155 mimic and NC group, miR-155 mimic and P2X7R (-) group. The expression of miR-155 in carotid plaque of mice was detected by PCR. HE staining was used to show the intima of carotid artery. The expressions of P2X7R, NLRP3 inflammasome related proteins and IL-1β in plaque were detected by Western blot. Results: The expression of miR-155, P2X7R, NLRP3 inflammasome related proteins and IL-1β in miR-155 mimic group was significantly higher than that in NC group (P < 0.05). In miR-155 inhibitor group, it was the opposite. There was no significant difference in the expression of NLRP3 inflammasome related proteins and IL-1β between miR-155 mimic and NC group and miR-155 mimic group, but the protein expression of miR-155 mimic and P2X7R (-) group was significantly decreased (P < 0.05). Conclusion: In ApoE^−/− mice, miR-155 may regulate P2X7R to activate NLRP3 inflammasome and enhance inflammatory response, thus promoting the formation and development of atherosclerotic plaque.