全反式维甲酸对单侧输尿管梗阻大鼠肾脏TGF-β1/Smad3信号通路的影响

THE EFFECT OF ALL-TRANS RETINOIC ACID ON TGF-β1/SMAD3 SIGNALING PATHWAY AFTER UNILATERAL URETERAL OBSTRUCTION OF RATS

目的:探讨全反式维甲酸(ATRA)对单侧输尿管梗阻(UUO)大鼠肾脏组织TGF-β1/Smad3信号通路的影响。方法:雄性Wistar大鼠72只随机分成3组:假手术组、UUO组、ATRA干预组,每组均为24只。UUO组和ATRA组大鼠腹腔注射麻醉后,行左侧输尿管结扎术。在同样的条件下,假手术组只探及肾包膜。ATRA组自手术前一天起,每天给予ATRA(15mg/kg)溶液灌胃一次直至处死当天,假手术组和UUO组大鼠在相同条件下给予等容量生理盐水灌胃,各组大鼠于术后第21天处死,取其左侧肾脏。肾脏组织HE及Masson染色观察病理改变,计算肾间质纤维化(RIF)指数。免疫印迹(Western blot)和实时荧光定量逆转录—聚合酶链反应法(RT-PCR)检测肾脏组织Smad3的蛋白及其mRNA表达。免疫组织化学法检测肾脏组织TGF-β1、Ⅳ型胶原(Col-Ⅳ)和纤维连接蛋白(FN)的蛋白表达。结果:与UUO组比较,ATRA组大鼠肾脏组织RIF指数、TGF-β1、Col-Ⅳ和FN蛋白表达均明显降低(P<0.05),而肾脏组织Smad3的蛋白及其mRNA表达无明显差异(P>0.05)。结论:ATRA可能通过下调UUO大鼠肾脏组织TGF-β1的表达,从而减少ECM积聚而起到减轻RIF的作用;但ATRA对TGF-β1/Smad3信号通路的下游蛋白Smad3的表达无明显影响。

Objective：To evaluate the effect of all trans retinoic acid （ATRA） on TGF-β1/Smad3 signaling pathway in renal tubulointerstitial fibrosis rats treated with unilateral ureteral obstruction （UUO）. Methods：Seventy-two male Wistar rats were randomly assigned into three groups： sham operation group, UUO group and ATRA group, n =24, respectively. The disease in UUO and ATRA groups were established by left side ureteral ligation. The rats in sham-operated group （SHO） were only dissociated left ureter and not to be obstructed. From the first day before operation, the rats in ATRA group were administrated intragastrically with ATRA （15 mg/kg · d） daily. SHO and model groups were administrated by saline in the same volume. Rats in three groups were killed on 21 days after surgery and their kidneys were collected for examination. Histological changes of renal tubular interstitium were observed by HE and Masson staining, and the renal interstitial fibrosis （RIF） index was calculated. Western-blot and real-time reverse transcription polymerase chain reaction （real-time RT PCR） were performed to detect the protein and mRNA ex pression of Smad3. The protein expression of TGF-β1, Col-Ⅳ and FN was detected by immunohistochem istry method. Results： Compared with UUO group, at the same point of time, index of RIF, protein expressions of TGF-β1, Col-Ⅳ and FN in ATRA group expression of protein and mRNA of Smad3 in ATRA Conclusion：ATRA might step down the progression of were all significantly decreased （ P 〈0.05） ; but the group was not significantly decreased（ P 〉0.05）. RIF by decreasing the expression of protein of TGF-β1, but didn＇t effect the protein expression of Smad3 in TGF-β1/Smad3 signaling pathway.