HIF-1α抗心肌缺血再灌注炎性损伤的作用

目的:本文旨在通过稳定低氧诱导因子1α(HIF-1α)表达,探讨其在大鼠心肌缺血再灌注(I/R)所致炎性损伤中的作用及可能的机制。方法:60只清洁级雄性Wistar大鼠随机分为4组:假手术(sham)组、I/R组、HIF-1α稳定剂二甲基乙二酰甘氨酸(DMOG)+I/R组和HIF-1α抑制剂YC-1+I/R组。各组分别予相应处理后,用Western blot法检测心肌组织的Toll样受体4(TLR4)和核因子κB(NF-κB)的蛋白表达;real-time PCR检测白细胞介素1β(IL-1β)、IL-6、肿瘤坏死因子α(TNF-α)、TLR4和NF-κB的mRNA水平;并利用试剂盒检测心肌组织的髓过氧化物酶(MPO)活性;HE染色观察炎性细胞浸润情况。结果:HIF-1α可明显降低心肌组织中炎性细胞的浸润、MPO活性及炎症因子IL-1β、IL-6和TNF-α的mRNA水平,同时降低TLR4和NF-κB的mRNA及蛋白水平(P0.05)。结论:HIF-1α可减轻心肌I/R引起的炎性损伤,其机制可能与抑制TLR4/NF-κB信号通路激活有关。

Hypoxia-inducible factor-1α attenuates myocardial inflammatory injury induced by ischemia and reperfusion in rats

AIM:To investigate the role of hypoxia-inducible factor-1α (HIF-1α) stable expression in myocardial inflammatory injury induced by ischemia and reperfusion (I/R) in rats. METHODS:Male Wistar rats were randomly divided into 4 groups:sham operation (sham) group, I/R group, HIF-1α stabilizer dimethyloxalyl glycine (DMOG)+I/R group and HIF-1α inhibitor YC-1+I/R group. The protein expression of myocardial Toll-like receptor 4 (TLR4) and nuclear factor-κB (NF-κB) was determined by Western blot. The mRNA levels of interleukin (IL)-1β, tumor necrosis factor-α (TNF-α), IL-6, TLR4 and NF-κB were detected by real-time PCR. The myeloperoxidase (MPO) activity in the myocardial tissues was measured. HE staining was used to observe the infiltration of inflammatory cells. RESULTS:HIF-1α decreased the infiltration of inflammatory cells, the MPO activity, and the mRNA levels of inflammatory factors IL-1β, IL-6 and TNF-α in the myocardial tissues. HIF-1α also reduced the expression of TLR4 and NF-κB at mRNA and protein levels (P<0.05). CONCLUSION:The stable expression of HIF-1α has an anti-inflammatory effect on the myocardial tissues after I/R injury in rats. The mechanism may be related to the inhibition of TLR4/NF-κB signaling pathway.