缺氧对过氧化物酶体增殖物激活受体α表达的影响

Influence of hypoxia on peroxisome proliferator activated receptor α and its mechanisms

目的 研究不同程度缺氧条件下 ,肺癌A5 4 9细胞内过氧化物酶体增殖物激活受体α(PPARα)和缺氧诱导因子 1α(HIF 1α)的表达状况 ,及反义封闭HIF 1α后 ,对PPARα表达的影响 ,以了解PPARα和HIF 1α的相关性。方法 首先将A5 4 9细胞分为 4组 :正常对照组 (A组 )、缺氧 2 4小时组(B组 )、缺氧 4 8小时组 (C组 )、缺氧 72小时组 (D组 )。观察不同缺氧时间对PPARα及HIF 1α蛋白和mRNA表达水平的影响。为观察HIF 1α对PPARα表达状况的影响 ,再设计 4组 :对照组 2 (E组 ) ,HIF 1α反义寡核苷酸组 (F组 ) ,HIF 1α正义寡核苷酸组 (G组 ) ,HIF 1α错义寡核苷酸组 (H组 )。结果 正常对照组 ,PPARα和HIF 1α蛋白及mRNA均有少量表达 ;随着缺氧时间的延长 ,两者的表达水平逐渐升高。在缺氧 2 4小时 ,两者mRNA和蛋白开始增高 ,4 8小时明显增高 ,至 72小时达到高峰。反义封闭HIF 1α后 ,PPARα蛋白及mRNA的表达水平明显下降。结论 PPARα及HIF 1α的表达水平随肿瘤细胞缺氧信号的加强而增加 ,且PPARα受HIF 1α的调控。

Objective To study the expressions of peroxisome proliferator activated receptor α(PPAR-α) and hypoxia-inducible factor-1α(HIF-1α) during different hypoxia states in lung cancer cell A549, and to investigate the mechanism of HIF-1α induced PPARα expression. Methods Firstly, lung cancer cells (A549) were divided into four groups: group A(control group); group B(hypoxia 24 h); group C(hypoxia 48 h); group D(hypoxia 72 h). The mRNA and protein of PPAR-α and HIF-1α were detected by RT-PCR and Western-blot on different groups. Secondly, the lung cancer cells(A549) were further divided into four groups: group E(control group); group F(antisense group); group G(sense group); group H(false-sense group). The influence of antisense oligonucleotide HIF-1α on PPAR-α was detected by RT-PCR and Western-blot. Results Comparing with group A, the expressions of the mRNA and protein of PPAR-α and HIF-1α increased significantly in group B, and reached peak in group D. Conversely, the expressions of the mRNA and protein of PPAR-α were decreased after antisense oligonuclei of HIF-1α in group F, as compared with group E. Conclusions The expressions of the mRNA and protein of PPAR-α and HIF-1α are increased by hypoxia, and PPAR-α may be regulated by HIF-1α.