芝麻素对脓毒症心肌损害的影响及机制研究

Effect and underlying mechanism of sesamin on myocardial damage in septic mice

目的研究芝麻素在脓毒症心肌损害中的影响及机制。方法随机选取24只雄性C57BL/6J小鼠分为生理盐水组、芝麻素组、脂多糖组(脂多糖+生理盐水)、脂多糖+芝麻素组(n=6)。建立脓毒性心肌病模型,分别检测各组心肌细胞损伤标志物乳酸脱氢酶(LDH)、肌酸激酶同工酶(CK-MB)和心功能指标LVEF、左心室短轴缩短率(LVFS)、左心室收缩末期内径(LVESD)。另取H9C2细胞随机分为磷酸盐缓冲液(PBS)组、脂多糖2组、脂多糖+芝麻素2组、PBS+腺苷酸活化蛋白激酶(AMPK)的小干扰RNA(siAMPK)组、脂多糖+siAMPK组、脂多糖+芝麻素+siAMPK组(n=6),给予芝麻素或等体积PBS处理后,构建脂多糖诱导心肌损伤细胞模型,检测各组细胞活性。结果与生理盐水组比较,脂多糖组CK-MB、LDH、LVESD、白细胞介素(IL)-1β、IL-18、TNF-α、单核细胞趋化蛋白1(MCP-1)mRNA表达和Bax蛋白表达明显升高,LVEF、LVFS明显降低(P<0.05);与脂多糖组比较,脂多糖+芝麻素CK-MB、LDH、LVESD、IL-1β、IL-18、TNF-α、MCP-1 mRNA表达和Bax蛋白表达明显降低,LVEF、LVFS明显升高(P<0.05)。脂多糖+芝麻素组磷酸化AMPK表达较脂多糖组明显升高(P<0.05)。脂多糖+芝麻素2组刺激12 h细胞活力明显高于脂多糖2组[(65.00±3.59)%vs(37.67±3.06)%,P<0.05]。脂多糖2组IL-1β和TNF-αmRNA表达明显高于PBS组和脂多糖+芝麻素2组(P<0.05)。脂多糖+芝麻素+siAMPK组与脂多糖+siAMPK组细胞活力,IL-1β和TNF-αmRNA表达比较,差异无统计学意义(P>0.05)。结论芝麻素对脓毒症心肌损害具有保护作用,可以缓解炎症与凋亡,此作用是通过促进AMPK磷酸化实现的。

Objective To investigate the effect of sesamin(SES)on myocardial damage in sepsis and its mechanism.Methods Male C57BL/6J mice were randomly divided into normal saline(NS)group,NS+SES group,LPS group(LPS+NS),and LPS+SES group(n=6).The septic cardiomyopathy model was established.Cardiomyocyte injury markers and cardiac function were detected respectively,and the expression changes of related molecules were detected.The H9C2 cells were randomly divided into PBS group,LPS 2 group,LPS+SES 2 group,PBS+AMPK+siAMPK group,LPS+siAMPK group,and LPS+SES+siAMPK group(n=6).The effect on cell viability in the H9C2 cells were detected.Results The levels of CK-MB,LDH,LVESD,mRNA levels of IL-1β,IL-18,TNF-α,MCP-1 and Bax protein were significantly increased,and LVEF and LVFS were significantly decreased in the LPS group then the NS group(P<0.05).The levels of CK-MB,LDH,LVESD,mRNA levels of IL-1β,IL-18,TNF-α,MCP-1 and Bax protein were significantly lower,while LVEF and LVFS were significantly higher in the LPS+SES group than the LPS group(P<0.05).The expression of p-AMPK in the LPS+SES group was higher than that in the LPS group(P<0.05).The cell viability after stimulation for 12 h was significantly higher in the LPS+SES 2 group than the LPS 2 group(65.00%±3.59%vs 37.67%±3.06%,P<0.05).The mRNA levels of IL-1βand TNF-αwere significantly higher in the LPS 2 group than in the PBS group and the LPS+SES 2 group(P<0.05).Silence of AMPK showed no effect on cell viability in the H9C2 cells from the LPS+SES+siAMPK group and LPS+siAMPK group,or on the mRNA levels of IL-1βand TNF-α(P>0.05).Conclusion SES has a protective effect on my-ocardial damage in sepsis,and can alleviate inflammation and apoptosis.This effect is due to its promoting the phosphorylation of AMPK.