LXA_4通过p38MAPK/Nrf2信号通路诱导H9c2心肌细胞HO-1高表达

LXA_4 increases the expression of HO-1 by activation of p38MAPK/Nrf2 pathway in H9c2 cardiomyocytes

目的:探讨脂氧素A4(lipoxin A4,LXA4)诱导心肌细胞H9c2中血红素加氧酶(heme oxygenase,HO)-1表达可能涉及的信号转导通路。方法:分别用核因子E2相关因子2(nuclear factor-E2 related factor 2,Nrf2)的抑制剂ATRA、p38MAPK的抑制剂SB203580、LXA4联合ATRA、LXA4联合SB03580预处理H9c2细胞后进行缺氧/复氧处理,RT-PCR、Western blot、免疫荧光等检测HO-1、Nrf2以及p38MAPK mRNA和蛋白表达的变化。结果:与只行缺氧/复氧处理的细胞相比,LXA4预处理的H9c2细胞HO-1 mRNA和蛋白的表达明显升高(P<0.05),而ATRA、SB203580分别抑制了Nrf2的聚集和p38MAPK的磷酸化(P<0.05),从而抑制了LXA4对HO-1的诱导(P<0.05)。结论:LXA4预处理诱导心肌细胞H9c2的HO-1高表达,具有抗缺氧/复氧损伤的作用,其机制与p38MAPK/Nrf2信号通路有关。

Objective：To investigate the possible mechanisms of signal transduction pathways of heme oxygenase （HO）-I expression induced by lipoxin A4 （LXA4） in H9c2 cardiomyocytes, nethods：H9c2 cells were exposed to hypoxia followed by reoxygenation with or without pretreatment of LXA4,nuclear factor-E2 related factor 2 （Nrf2） inhibitor （ATRA）,p38MAPK inhibitor （SB203580）,LXA4 combined with ATRA,and LXA4 combined with SB203580. The mRNA transcription and protein expression of HO-1,Nrf2 and p38MAPK was examined by RT-PCR,Westem blot and immunofluorescence staining. Results：Compared with hypoxia/reoxygenation group,the mRNA transcription and protein expression of HO-1 in H9c2 cardiomyocytes pretreated with LXA~ increased significantly（P 〈 0.05）. The expression of HO-1 in H9c2 cardiomyocytes decreased （P 〈 0.05） after treated with ATRA or SB203580. ATRA blocked the nuclear accumulation of Nrf2 and decreased HO-1 protein expression induced by LXA4 pretreatment （P 〈 0.05）. SB203580 inhibited the phosphorylation level of p38MAPK and decreased HO-1 protein expression induced by LXA4 pretreatment（P 〈 0.05）. Conclusion：LXA4 can induce HO-1 over-expression which has protective effect on H9c2 cardiomyocytes of hypoxia/reoxygenation injury. Its mechanism is related to p38MAPK/Nrf2 signal transduction pathways.