Jia Lining, Ma Xiaotao, Gui Baosong, Ge Heng, Wang Li, Ou Yan, Tian Lifang, Chen Zhao, Duan Zhaoyang, Han Jin, Fu Rongguo
Department of Nephropathy, The Second Affiliated Hospital of Xi'an Jiaotong University, Xi'an, China.
PLoS One. 2015 Feb 13;10(2):e0117757. doi: 10.1371/journal.pone.0117757. eCollection 2015.
This study was to investigate whether sorafenib can inhibit the progression of renal fibrosis and to study the possible mechanisms of this effect.
Eight-week-old rats were subjected to unilateral ureteral obstruction (UUO) and were intragastrically administered sorafenib, while control and sham groups were administered vehicle for 14 or 21 days. NRK-52E cells were treated with TGF-β1 and sorafenib for 24 or 48 hours. HE and Masson staining were used to visualize fibrosis of the renal tissue in each group. The expression of α-SMA and E-cadherin in kidney tissue and NRK-52E cells were performed using immunohistochemistry and immunofluorescence. The apoptosis rate of NRK-52E cells was determined by flow cytometry analysis. The protein levels of Smad3 and p-Smad3 in kidney tissue and NRK-52E cells were detected by western blot analysis.
HE staining demonstrated that kidney interstitial fibrosis, tubular atrophy, and inflammatory cell infiltration in the sorafenib-treated-UUO groups were significantly decreased compared with the vehicle-treated-UUO group (p<0.05). Masson staining showed that the area of fibrosis was significantly decreased in the sorafenib-treated-UUO groups compared with vehicle-treated-UUO group (p<0.01). The size of the kidney did not significantly increase; the cortex of the kidney was thicker and had a richer blood supply in the middle-dose sorafenib group compared with the vehicle-treated-UUO group (p<0.05). Compared with the vehicle-treated-UUO and TGF-β-stimulated NRK-52E groups, the expression of a-SMA and E-cadherin decreased and increased, respectively, in the UUO kidneys and NRK-52E cells of the sorafenib-treated groups (p<0.05). The apoptotic rate of NRK-52E cells treated with sorafenib decreased for 24 hours in a dose-dependent manner (p<0.05). Compared with the vehicle-treated UUO and TGF-β-stimulated NRK-52E groups, the ratio of p-Smad3 to Smad3 decreased in the sorafenib-treated groups (p<0.05).
Our results suggest that sorafenib may useful for the treatment of renal fibrosis through the suppression of TGF-β/Smad3-induced EMT signaling.
本研究旨在探讨索拉非尼是否能抑制肾纤维化的进展，并研究其作用的可能机制。
8周龄大鼠接受单侧输尿管梗阻（UUO），并经胃给予索拉非尼，而对照组和假手术组给予赋形剂，持续14或21天。NRK-52E细胞用转化生长因子-β1（TGF-β1）和索拉非尼处理24或48小时。采用苏木精-伊红（HE）染色和Masson染色观察各组肾组织纤维化情况。用免疫组织化学和免疫荧光法检测肾组织和NRK-52E细胞中α-平滑肌肌动蛋白（α-SMA）和E-钙黏蛋白的表达。通过流式细胞术分析测定NRK-52E细胞的凋亡率。用蛋白质印迹法检测肾组织和NRK-52E细胞中Smad3和磷酸化Smad3（p-Smad3）的蛋白水平。
HE染色显示，与赋形剂处理的UUO组相比，索拉非尼处理的UUO组肾间质纤维化、肾小管萎缩和炎性细胞浸润明显减轻（p<0.05）。Masson染色显示，与赋形剂处理的UUO组相比，索拉非尼处理的UUO组纤维化面积明显减小（p<0.01）。肾脏大小无明显增加；中剂量索拉非尼组肾脏皮质比赋形剂处理的UUO组更厚，血供更丰富（p<0.05）。与赋形剂处理的UUO组和TGF-β刺激的NRK-52E组相比，索拉非尼处理组的UUO肾脏和NRK-52E细胞中α-SMA表达降低，E-钙黏蛋白表达增加（p<0.05）。索拉非尼处理24小时的NRK-52E细胞凋亡率呈剂量依赖性降低（p<0.05）。与赋形剂处理的UUO组和TGF-β刺激的NRK-52E组相比，索拉非尼处理组p-Smad3与Smad3的比值降低（p<0.05）。
我们的结果表明，索拉非尼可能通过抑制TGF-β/Smad3诱导的上皮-间质转化（EMT）信号通路来治疗肾纤维化。
