番茄红素减轻H9C2心肌细胞缺氧/复氧致内质网应激的相关机制

Mechanism of lycopene in alleviating endoplasmic reticulum stress induced by hypoxia/reoxygenation in H9C2 cardiomyocytes

目的探讨番茄红素减轻H9C2心肌细胞缺氧/复氧(H/R)致内质网应激(ERS)的相关机制。方法 H9C2心肌细胞随机分为:(1)空白对照组、(2)番茄红素组、(3)H/R组、(4)番茄红素+H/R组、(5)4-苯基丁酸(4-phenyl butyric acid,4-PBA)+H/R组、(6)毒胡萝卜素内酯(thapsigargin,TG)组、(7)番茄红素+TG组。流式细胞术检测H9C2心肌细胞凋亡比例;Western blot检测葡萄糖调节蛋白(glucose-regulated proteins,GRP)78、C/EBP环磷酸腺苷反应元件结合转录因子同源蛋白(C/EBP homologous protein,CHOP)、c-Jun氨基末端激酶(c-Jun-N-terminal protein kinase,JNK)、磷酸化JNK(p-JNK)及半胱氨酸天冬氨酸蛋白酶(Casepase)-12的表达。结果与对照组相比,H/R组及TG组细胞的细胞凋亡比例、GRP78、CHOP、p-JNK和Caspase-12蛋白表达量明显增加(P<0.01);与H/R组相比,细胞凋亡比例及上述蛋白表达在番茄红素+H/R组与4-PBA+H/R组明显下降(P<0.01);与TG组相比,细胞凋亡比例及上述蛋白表达在番茄红素+TG组也明显下降(P<0.01);而番茄红素+H/R组与4-PBA+H/R组相比差异不具有统计学意义。JNK蛋白总量表达无明显变化。结论番茄红素通过抑制ERS致凋亡的相关信号通路CHOP、p-JNK和Caspase-12对H/R H9C2心肌细胞起到保护作用。

AIM To explore the possible mechanism of lycopene in alleviating endoplasmic reticulum stress （ERS） induced by hypoxia/reoxygenation （H/R） in H9C2 cardiomyocytes. METHODS H9C2 cardiomyocytes were randomly divided into control group, lycopene group, H/R group, lycopene＋H/R group, 4-phenyl butyric acid （4-PBA）＋H/R group, thapsigargin （TG） group, and lycopene＋TG group. The apoptosis ratio of H9C2 cardiomyocytes was detected and the expressions of protein of glucose-regulated proteins 78 （GRP78）, C/EBP homologous protein （CHOP）, c-Jun-N-terminal protein kinase （JNK）, phosphorylation of JNK （p-JNK） and caspase-12 were detected by Western blot. RESULTS The apoptosis ratio and the expressions of protein of GRP78, CHOP, JNK, p-JNK and caspase-12 increased markedly in H/R group and TG group in comparison with those in the control group （P〈0.01）. They decreased markedly in lycopene＋H/R group and 4-PBA＋H/R group compared with those in H/R group （P〈0.01） and in lycopene＋TG group compared with those in TG group （P〈0.01）. No statistically significant difference was found between lycopene＋H/R group and 4-PBA＋H/R group. No significant difference was found in the changes of the expression of protein of JNK. CONCLUSION Lycopene may exert its protective effect on H/R H9C2 cardiomyocytes through inhibiting the key signaling pathways of CHOP, p-JNK and caspase-12 to reduce ERS.