Department of Clinical Laboratory, Renmin Hospital of Wuhan University, District of Wuchang, Wuhan, Hubei, China.
Lipids Health Dis. 2012 Oct 11;11:135. doi: 10.1186/1476-511X-11-135.
Cardiomyocytes apoptosis is an important contributor to myocardial dysfunction and heart failure. Adiponectin has cardioprotective effects, potential mechanisms behind it are not clear in cardiomyocytes. The purpose of the study was to investigate whether adiponectin can block palmitate-induced apoptosis and the underlying biochemical mechanism in H9c2 cells.
H9c2 cells were treated with palmitate presence or absence of 2.5 μg/mL globular adiponectin. The effect on the cell viability of H9c2 cells was evaluated using MTT assay, and cell apoptosis was determined by Hoechst 33342 staining. Protein expression was measured using the western blot method.
Our results showed that the palmitate treatment induced apoptosis in H9c2 cells, which was associated with increasing the level of cleaved caspase-3 and cleaved PARP. Meanwhile, palmitate-induced apoptosis increased the protein level of p-ERK1/2, and decreased the protein level of p-Akt significantly. However, levels of both of these proteins were restored to the normal when pretreated with adiponectin, and followed with the decrease of cleaved caspase-3 and cleaved PARP. In line with these results, the protective effect of adiponectin can be blocked by PI3K/Akt inhibitor LY294002, and palmitate-induced apoptosis can be attenuated by ERK1/2 inhibitor U0126.
Taken together, the present study demonstrated that adiponectin protects H9c2 cells from palmitate-induced apoptosis via PI3K/Akt and ERK1/2 signaling pathways. Our results reveal a link between adiponectin and cardiomyocytes apoptosis, suggesting that adioponectin may be a promising therapeutic for the treatment of lipotoxicity cardiomyopathy.
心肌细胞凋亡是心肌功能障碍和心力衰竭的一个重要原因。脂联素具有心脏保护作用,但在心肌细胞中其潜在的作用机制尚不清楚。本研究旨在探讨脂联素是否能阻断软脂酸诱导的 H9c2 细胞凋亡及其潜在的生化机制。
用软脂酸处理 H9c2 细胞,同时存在或不存在 2.5μg/ml 球形脂联素。用 MTT 法测定 H9c2 细胞活力,用 Hoechst 33342 染色法测定细胞凋亡。用 Western blot 法测定蛋白表达。
我们的结果表明,软脂酸处理诱导 H9c2 细胞凋亡,与增加 cleaved caspase-3 和 cleaved PARP 的水平有关。同时,软脂酸诱导的细胞凋亡增加了 p-ERK1/2 的蛋白水平,显著降低了 p-Akt 的蛋白水平。然而,当用脂联素预处理时,这两种蛋白的水平都恢复到正常水平,随之 cleaved caspase-3 和 cleaved PARP 的水平降低。与这些结果一致的是,脂联素的保护作用可以被 PI3K/Akt 抑制剂 LY294002 阻断,而 ERK1/2 抑制剂 U0126 可以减轻软脂酸诱导的细胞凋亡。
综上所述,本研究表明脂联素通过 PI3K/Akt 和 ERK1/2 信号通路保护 H9c2 细胞免受软脂酸诱导的凋亡。我们的结果揭示了脂联素与心肌细胞凋亡之间的联系,提示脂联素可能是治疗脂毒性心肌病的一种有前途的治疗方法。