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400 μmol/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、80 μmol/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 400 μmol/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, 80 μmol/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.