姜黄素下调miR-155抑制缺血性脑卒中炎性应答的实验研究

Study on curcumin inhibits inflammation response in ischemic stroke via down-regulating miR-155

目的分析姜黄素对缺血性脑卒中的抗炎作用,并探讨miR-155、Toll样受体4(TLR4信号通路是否参与该抗炎机制。方法线栓法建立Sprague Dawley大鼠大脑中动脉闭塞模型(MCAO),将大鼠分为假手术组(8例)、MCAO模型组(8例)、姜黄素治疗组(8例),检测大鼠梗死体积、miR-155 mRNA相对表达量以及TLR4蛋白表达情况,ELISA法检测大鼠肿瘤坏死因子-α(TNF-α)、白介素-6(IL-6)、白介素-1β(IL-1β)表达。结果姜黄素显著改善MCAO大鼠脑梗死体积、神经系统功能评分以及运动功能(P<0.05),可显著降低MCAO大鼠miR-155mRNA、TLR4蛋白以及炎性因子TNF-α、IL-6、IL-1β的表达(均P<0.05)。结论姜黄素主要通过下调miR-155/TLR4信号通路抑制缺血性脑卒中的炎性应答。

Objective To investigate the anti-inflammation effect of curcumin on ischemic stroke and whether miR155 and toll-like receptor 4(TLR4)signaling pathways were involved in the anti-inflammatory mechanism.Methods Suture-occluded method was used to establish the middle cerebral artery occlusion(MCAO)model in Sprague Dawley rats.Rats were divided into sham group(n=8),MCAO model group(n=8)and curcumin treated group(n=8).Areas of cerebral infarction were calculated and expressions of miR-155 mRNA and TLR4 protein were detected.ELISA was used to assess the expressions of tumor necrosis factor-α(TNF-α),interleukin-6(IL-6)and interleukin-1β(IL-1β).Results Curcumin significantly decreased volume of cerebral infarction(P<0.05),modified neurological function score and motor function(P<0.05),and down-regulated the expressions of miR-155 mRNA(P<0.05),TLR4(P<0.05)and levels of inflammation cytokines including TNF-α,IL-6 and IL-1β(P<0.05)in MACO rats.Conclusion Curcumin suppresses the inflammation response in ischemic stroke via down-regulating the miR-155/TLR4 signaling pathway.