去甲氧基姜黄素对毒胡萝卜素诱导乳鼠心肌细胞内质网应激的影响

Effect of DMC on TG-Induced ERS in Myocardial Cells of Neonatal Rats

目的:探讨去甲氧基姜黄素(DMC)对毒胡萝卜素内酯(TG)诱导的乳鼠心肌细胞内质网应激(ERS)的作用和机制,及其对相关分子葡萄糖调节蛋白78(GRP78)和C/EBP环磷酸腺苷反应元件结合转录因子同源蛋白(CHOP)的影响。方法:体外培养乳鼠心肌细胞,随机分为4组:①对照组细胞不做任何药物处理;②模型组加入1μmol/L TG处理24 h,建立ERS模型;③DMC低浓度组同时加入1μmol/L TG和10μmol/L DMC处理24 h;④DMC高浓度组同时加入1μmol/L TG和30μmol/L DMC处理24 h。采用CCK8法检测心肌细胞活性,流氏细胞法检测心肌细胞凋亡,检测细胞匀浆中乳酸脱氢酶(LDH)、丙二醛(MDA)、超氧化物歧化酶(SOD)的含量,Western Blot法检测GRP78和CHOP蛋白表达。结果:与对照组相比,模型组细胞活性显著降低,细胞凋亡率明显增加,LDH及MDA含量升高,而SOD活力则降低,GRP78和CHOP蛋白表达显著升高,P<0.05;与模型组比较,不同浓度DMC干预后,细胞活性升高,细胞凋亡率明显减少,LDH及MDA含量显著降低,SOD活力则显著升高,并且GRP78和CHOP蛋白表达降低,P<0.05。结论:去甲氧基姜黄素通过抑制GRP78和CHOP蛋白表达来减轻TG所致的内质网应激损伤,减少细胞凋亡,从而对心肌细胞起到保护作用。

Objective: To explore the effect and mechanism of Demethoxycurcumin(DMC) on endoplasmic reticulum stress(ERS) induced by Thapsigargin(TG) in cardiomyocytes of neonatal rats, and to explore its influence to related molecules glucose regulated protein of GRP78 and CHOP. Methods: The cardiomyocytes of neonatal rats were cultured and were randomly divided into four groups. The cardiomyocytes were not intervened in the control group. In the model group, 1 μmol/L TG were added to establish ERS model. In DMC low concentration group, 1 μmol/L TG were added and 10 μmol/L DMC intervention was applied for 24 h at the same time. In DMC high concentration group, 1 μmol/L TG were added and 30 μmol/L DMC was applied simultaneously for 24 h. The CCK8 method was used to detect the activity of cardiomyocytes, and the flow cytometry was used to detect cardiomyocyte apoptosis. The contents of LDH, MDA and SOD in cell homogenate were all detected. The protein expressions of CHOP and GRP78 were detected respectively by Western Blot method. Results: Compared to the control group, the activity of the cells significantly decreased, the apoptosis rate increased remarkably, the levels of MDA and LDH increased, and the SOD activity decreased, and the protein expressions of GRP78 and CHOP significantly increased in the model group(P<0.05). Compared to the model group, after interventions with different concentrations of DMC, the cell activity increased, the apoptosis rate decreased significantly, the levels of LDH and MDA decreased markedly, the SOD activity resulted in a marked increase, and the protein expressions of GRP78 and CHOP decreased(P<0.05). Conclusion: DCM can alleviate the injury of TG-induced ERS and reduce apoptosis by inhibiting the protein expressions of GRP78 and CHOP, thereby protecting cardiomyocytes.