PPAR-γ 过表达缓解肾缺血再灌注大鼠纤维化和炎性因子的 异常表达

目的 观察过氧化物酶体增殖物活化受体 γ (PPAR-γ) 过表达对大鼠肾缺血再灌注 (RI/ R) 损 伤的保护作用, 并探讨其作用机制。 方法 将 40 只 SD 大鼠随机分为对照组、 RI/ R 模型组、 RI/ R + LV 组 和 RI/ R + PPAR-γ 组, 10 只/ 组, 采用手术阻断双侧肾动脉血流构建 RI/ R 损伤模型; RI/ R + PPAR-γ 组于 恢复再灌注前经尾静脉注射 PPAR-γ 重组慢病毒载体, RI/ R + LV 组注射含有空质粒的慢病毒载体, RI/ R 模型组注射等量生理盐水。 再灌注结束后, 通过 HE 和 Masson 染色观察肾组织病理改变; 全自动生化分析 仪检测尿蛋白、 血肌酐 ( Scr)、 血尿素氮 ( BUN) 水平; ELISA 法检测血清和肾组织肿瘤坏死因子 α (TNF-α)、 白介素 6 ( IL-6) 含量; RT-PCR 检测肾组织 PPAR-γ mRNA 表达; 蛋白质印迹法检测肾组织 PPAR-γ、 转化生长因子 β (TGF-β)、 α 平滑肌肌动蛋白 (α-SMA)、 纤维连接蛋白 (FN) 以及凋亡相关蛋 白 Bax、 Bcl-2、 caspase-3、 Cleaved caspase-3、 caspase-9、 Cleaved caspase-9 表达。 结果 与对照组比较, RI/ R 模型组 PPAR-γ 水平降低 (P< 0. 05), 尿蛋白、 Scr、 BUN、 TNF-α、 IL-6、 Bax / Bcl-2、 Cleaved caspase-3 / caspase-3、 Cleaved caspase-9 / caspase-9、 TGF-β、 α-SMA、 FN 水平升高 (P< 0. 05)。 与 RI/ R 模型组比较, RI/ R + PPAR-γ 组 PPAR-γ 水平升高 ( P< 0. 05), 尿蛋白、 Scr、 BUN、 TNF-α、 IL-6、 Bax / Bcl-2、 Cleaved caspase-3 / caspase-3、 Cleaved caspase-9 / caspase-9、 TGF-β、 α-SMA、 FN 水平降低 (P< 0. 05)。 结论 过表 达 PPAR-γ 可通过减少促炎细胞因子释放, 改善肾纤维化而减少 RI/ R 损伤。

PPAR-γ Overexpression Alleviates Fibrosisand Abnormal Expression of Inflammatory Factors in Rats Undergoing Renal Ischemia-Reperfusion

Objective To observe the protective effect of peroxisome proliferator-activated receptor γ (PPAR-γ) overexpression against renal ischemia-reperfusion (RI/ R) injury in rats, and explore its mechanism. Methods A total of 40 SD rats were randomly divided into 4 groups as follows: the control group, the RI/ R model group, the RI/ R + LV group and the RI/ R + PPAR-γ group, 10 cases in each group. The blood flow of bilateral renal artery was blocked by surgery to construct the RI/ R injury model. Before reperfusionrecovery, rats in the RI/ R + PPAR-γ group were injected with PPAR-γ recombinant lentiviral vector through the tail vein, rats in the RI/ R + LV group were injected with the lentiviral vector containing empty plasmid, while rats in the RI/ R model group wereinjected withnormal saline. After reperfusion, pathological changes in renal tissues were observed by HE staining and Masson staining. The levels of urine protein, serum creatinine (Scr) and blood urea nitrogen (BUN) were measuredby automatic biochemical analyzer. The levels of tumor necrosis factor-α (TNF-α) and interleukin 6 ( IL-6) in serum and renal tissues were determinedby ELISA. The expression level of PPAR-γ mRNA in renal tissues was detected by RT-PCR. The expression levels of PPAR-γ, transforming growth factor β (TGF-β), α-smooth muscleactin ( α-SMA), fibronectin ( FN) and apoptosis-related proteins ( Bax, Bcl-2, caspase-3, Cleaved caspase-3, caspase-9, Cleaved caspase-9) in renal tissues were detectedby Western blotting. Results Compared with the control group, levels of PPAR-γ mRNA and protein were decreased in the RI/ R model group (P< 0. 05), while levels of urine protein, Scr, BUN, TNF-α, IL-6, Bax / Bcl-2, cleaved caspase-3 / caspase-3, cleaved caspase-9 / caspase-9, TGF-β, α-SMA and FN were increased (P< 0. 05). Compared with the RI/ R model group, levels of PPAR-γ mRNA and protein were increased in the RI/ R + PPAR-γ group (P< 0. 05), while levels of urine protein, Scr, BUN, TNF-α, IL-6, Bax / Bcl-2, cleaved caspase-3 / caspase-3, cleaved caspase-9 / caspase-9, TGF-β, α-SMA and FN were decreased (P < 0. 05). Conclusion Overexpression of PPAR-γ can improve renal fibrosis by reducing the release of pro-inflammatory cytokines, thus decreasing RI/ R injury.