钴原卟啉对H9c2心肌细胞缺氧/复氧损伤的保护作用

Protective effect of COPP on hypoxia/reoxygenation injury of H9c2 myocytes

目的研究钴原卟啉(COPP)预处理在H9c2心肌细胞缺氧/复氧损伤中的作用及分子机制。方法建立H9C2心肌细胞缺氧/复氧模型。在H9c2心肌细胞缺氧/复氧前用COPP预处理,并用锌原卟啉(Znpp),全反视黄酸(ATAR)分别抑制HO-1及Nrf2-ARE。检测细胞上清液中LDH、CK的水平变化;用RT-PCR法分析HO-1mRNA表达水平;Westernblot分析HO-1、Nrf2的蛋白表达水平。结果与缺氧/复氧组比,COPP预处理组中LDH和CK水平均明显降低,而HO-1mRNA水平,蛋白水平及细胞核的Nrf2蛋白水平均明显增加;Znpp的加入阻断了COPP预处理对心肌细胞的保护作用;ATAR的加入抑制了Nrf2在细胞核的聚集,进而抑制了COPP对HO-1的诱导。结论COPP预处理诱导H9c2心肌细胞HO-1过表达,具有抗心肌细胞缺氧/复氧损伤的保护作用;其机制与Nrf2-ARE信号通路相关。

Aim To study the effect and molecular mechanism of pretreatment with COPP on hypoxia/ reoxygenation injury of H9c2 myocytes. Methods H9c2 myocytes model of hypoxia/reoxygenation injury was established and H9c2 myocytes were given COPP pretreatment before hypoxia/reoxygenation. Treatment with Znpp and all-traMs retinoic acid （ATRA）inhibited HO-1 and Nrf2-ARE respectively. The level of LDH and CK in cell supernatants were measured. HO-1 mRNA expression was analyzed by RT-PCR. HO-1 and Nrf2 protein expressions were analyzed by Western blot. Results Compared with hypoxia/reoxygenation group, the level of LDH and CK in COPP pretreatment groups decreased significantly and the level of HO- lmRNA, HO-1 protein expression and Nrf2 protein expression in the nucleus significantly increased. Znpp abolished protective effect of COPP pretreatment. ATRA blocked the nuclear accumulation of Nrf2 and decreased HO-1 protein expression that COPP pretreat- ment induced. Conclusions COPP can induce HO-1 overexpression which has protective effect on hypoxia/ reoxygenation injury of H9c2 myocytes. Its mechanism is related to Nrf2-ARE signaling pathway.