大鼠肾脏损伤早期HIF-1α、PPAR-γ的表达及其对肾脏的保护机制

Expressions of HIF-1α and PPAR-γ in renal early trauma and their protective mechanisms on the kidney

目的探讨经体表创伤后肾脏组织中缺氧诱导因子-1α(HIF-1α)、过氧化物酶体增殖物激活受体γ(PPAR-γ)表达的变化,及创伤后肾脏损伤与修复的作用机制。方法采用自由落体生物撞击仪撞击大鼠脊肋区复制创伤动物模型。实验大鼠分为5组,包括非创伤对照组,创伤后1、6、12、24 h组。采用免疫组织化学方法进行HIF-1α、PPAR-γ染色。结果肾脏创伤后1、24 h HIF-1α表达增强,分布于皮质远曲小管、肾盏旁小管、髓质小管;6、12 h表达减弱,局限于肾盏旁小管、髓质外带小管。各组间比较差异有统计学意义(P<0.05)。PPAR-γ1、24 h呈阳性表达,分布于髓质小管上皮细胞;6、12 h呈阴性表达,各组间比较差异有统计学意义(P<0.05)。结论 HIF-1α、PPAR-γ可能参与了肾脏创伤后缺血、缺氧、再生、修复的过程。

Objective To investigate expressions of hypoxia-inducible factor-1α（HIF-1α） and peroxisome proliferator-activated receptor-gamma（PPAR-γ） in traumatic kidneys,and the mechanisms of kidney trauma and repair.Methods Rats were stricken at the skin of the renal zone by a free-fall from 45 cm height to establish the traumatic rat model.Then,rats were randomly divided into 5 groups： the non-traumatic control group,and 1 h,6 h,12 h and 24 h post-trauma groups.Expressions of HIF-1α and PPAR-γwere detected with immunohistochemical staining.Results Positive expression of HIF-1αwas increased in 1 h and 24 h post-trauma groups,located in cortex distal convoluted tubules,tubules near renal calyces and medullary tubules;while it was distinctly decreased in 6h and 12 h post-trauma groups,located in tubules near renal calyces and tubules at the outer zone of renal medulla.There were significant differences in expression of HIF-1αamong all the groups（P0.05）.The PPAR-γ expression was positive in tubules of renal medulla in 1 h and 24 h post-trauma groups（P0.05）,however,negative in 6 h and 12 h post-trauma groups.Conclusion HIF-1αand PPAR-γ may participate in the secondary hypoxia,ischemia,regeneration and repair procedures after renal injury.