丹酚酸A抑制TLR4/JNK MAPK改善棕榈酸诱导的心肌细胞损伤

目的:研究丹酚酸A对脂毒性诱导的H9C2心肌细胞损伤的改善作用并初步探究其分子机制。方法:采用棕榈酸体外诱导建立H9C2心肌细胞脂毒性模型并给予丹酚酸A进行干预,采用乳酸脱氢酶法检测细胞损伤,采用细胞增殖-毒性检测试剂盒检测细胞存活率,采用罗丹明123染色观察心肌细胞线粒体膜电位变化,采用蛋白免疫印迹技术研究丹酚酸A改善作用的分子机制。结果:浓度为400μmol/L的棕榈酸可显著导致H9C2心肌细胞脂毒性损伤(P<0.05)。不同浓度(10、20、40、80μmol/L)丹酚酸A暴露对心肌细胞无毒性作用(P>0.05)。丹酚酸A干预显著改善脂毒性诱导的心肌细胞损伤及细胞线粒体膜电位降低(P<0.05)。激活Toll样受体4(Toll-like receptors,TLR4)可显著增强脂毒性诱导的心肌细胞损伤(P<0.05),而抑制TLR4显著减轻棕榈酸诱导的细胞脂毒性(P<0.05)。此外,丹酚酸A显著抑制棕榈酸诱导的TLR4及其下游c-Jun氨基末端激酶(c-Jun N-terminal kinase,JNK MAPK)(P<0.05)。结论:丹酚酸A改善脂毒性诱导的心肌细胞损伤,该保护作用可能与其抑制TLR4/JNK MAPK信号通路有关。

Salvianolic acid A improves palmitie acid-induced lipotoxicity in cardiomyocyte via inhibiting TLR4/JNK MAPK

AIM:To reveal the ameliorative effect of salvianolic acid A on palmitie acid-induced lipotoxicity in H9C2 cells and to explore its potential molecular mechanisms preliminarily.METHODS:H9C2 cell were induced by palmitie acid to establish a lipotoxicity model,while salvianolic acid A was added prior to palmitie acid treatment.Lactate dehydrogenase(LDH)was employed to detect cell damage.Cell counting Kit-8 was used to detect cell viability.The changes of mitochondrial membrane potential in cardiomyocyte were observed by rhodamine 123 staining.The molecular mechanisms of the ameliorative effect of salvianolic acid A was analyzed by Western Blotting.RESULTS:Palmitie acid at a concentration of 400μmol/L significantly caused lipotoxicity damage to H9C2 cells(P<0.05).There was no cytotoxic effect of different concentrations of salvianolic acid A(10,20,40,80μmol/L)treatment on H9C2 cells(P>0.05).Salvianolic acid A intervention significantly improved lipotoxicity-induced cell death and reduction of cell mitochondrial membrane potential(P<0.05).The activation of toll-like receptor 4(TLR4)significantly enhanced lipotoxicity-induced cell damage(P<0.05),while inhibition of TLR4 significantly reduced palmitie acid-induced lipotoxicity(P<0.05).In addition,salvianolic acid A effectively inhibited the upregulation of TLR4 and the downstream c-Jun N-terminal kinase(JNK MAPK)of TLR4 by palmitie acid treatment(P<0.05).CONCLUSION:Salvianolic acid A effectively improves lipotoxicity-induced cardiomyocyte damage.The inhibition of p38 signaling pathway is potentially involved in its protective effect.The protective effect may be related to the inhibition of TLR4/JNK MAPK signaling pathway,providing a potential molecular target for the prevention and treatment of lipotoxic cardiomyopathy.