过表达过氧化物酶体增殖物激活受体γ基因对小鼠缺氧性肾损伤的影响

Effects of overexpression of peroxisome proliferator activated receptor γ gene on hypoxic-induced renal injury in mice

目的探讨过表达过氧化物酶体增殖物激活受体γ(PPARγ)基因对小鼠缺氧性肾损伤的干预作用及可能机制。方法将15只雄性C57BL/6小鼠随机分为对照组、缺氧组和过表达组,每组5只。给予过表达组小鼠注射过表达PPARγ基因的腺相关病毒,对照组和缺氧组小鼠则注射等量生理盐水。3周后将缺氧组和过表达组小鼠放入低压低氧动物实验舱进行缺氧干预7 d。干预结束后取各组小鼠肾组织,光镜下观察肾组织病理学变化,并采用实时荧光定量PCR法和蛋白质印迹法检测各组小鼠肾组织中PPARγ、混合谱系蛋白激酶结构域样蛋白(MLKL)、转化生长因子β(TGF-β)的mRNA和蛋白相对表达量。结果与对照组比较,缺氧组肾组织中部分肾小管细胞肿胀,管腔狭窄堵塞,PPARγ的mRNA和蛋白相对表达量均明显降低,MLKL和TGF-β的mRNA和蛋白相对表达量均明显增高(均P<0.05)。与缺氧组比较,过表达组肾组织中肾小管病变相对轻微,PPARγ的mRNA和蛋白相对表达量均明显增高,MLKL和TGF-β的mRNA和蛋白相对表达量均明显降低(均P<0.05)。结论过表达PPARγ基因可减轻小鼠缺氧性肾损伤,其机制可能与减少肾脏细胞坏死性凋亡有关。

Objective To investigate the intervention effects and possible mechanism of overexpression of peroxisome proliferator activated receptorγ(PPARγ)gene on hypoxic-induced renal injury in mice.Methods Fifteen male C57BL/6 mice were randomly divided into control group,hypoxia group and overexpression group,with five mice in each group.Mice in the overexpression group were injected with adeno-associated virus overexpressing PPARγgene,and mice in the control and hypoxia groups were injected with the same amount of normal saline.Three weeks later,mice in the hypoxia and overexpression groups were placed into a hypobaric and hypoxic chamber for animal experiment for the hypoxia intervention for seven days.After the end of intervention,renal tissues were harvested from mice in each group,and the pathological changes in renal tissues were observed under the light microscope;in addition,real-time fluorescent quantitative PCR and Western blotting assay were used to detect the relative expression of mRNAs and proteins of PPARγ,mixed lineage kinase domain-like protein(MLKL),and transforming growth factorβ(TGF-β)in renal tissues of mice in each group.Results Compared with the control group,some renal tubular cells in renal tissues were swollen,with narrow and blocked tubular lumens,the relative expression of PPARγmRNA and protein was decreased significantly,and the relative expression of MLKL and TGF-βmRNAs and proteins was increased markedly in the hypoxia group(all P<0.05).Compared with the hypoxia group,the overexpression group exhibited relatively mild renal tubular lesions in renal tissues,obviously higher relative expression of PPARγmRNA and protein,and significantly lower relative expression of MLKL and TGF-βmRNAs and proteins(all P<0.05).Conclusion Overexpression of PPARγgene can alleviate hypoxia-induced renal injury in mice,the mechanism of which may be related to the reduction of necroptosis of renal cells.