BACKGROUND Ureteral obstruction causes injury of the renal tissues and can irreversibly progress to renal fibrosis, with atrophy and apoptosis of tubular cells. The goal of the current study was to examine the effects of rhein on the apoptosis o renal tubular cells as well as renal fibrosis using a rodent model of unilateral ureteral obstruction (UUO). METHODS UUO was induced through ureteral ligation, then animals received treatments with rhein or vehicle. The control rats only received sham operation. The renal tissue was harvested 1 week after surgery for assessment of kidney fibrosis. RESULTS The expressions of collagen I and α-smooth muscle actin (α-SMA), as well as the severity of renal tubular apoptosis and fibrosis were time-dependently increased following UUO. Treatments with rhein partially inhibited such responses. Renal interstitial fibrosis was associated with STAT3 (signal transducer and activator of transcription 3) phosphorylation as well as altered expressions of Bax and Bcl2, both apoptosis-related proteins. Treatment with rhein also partly blocked these responses. CONCLUSION These findings demonstrated that rhein mitigated apoptosis of renal tubular cell as well as renal fibrosis in a UUO rodent model. This curative effect is likely mediated via suppression of STAT3 phosphorylation.

中文翻译：

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大黄酸通过抑制大鼠肾小管细胞凋亡来减轻肾脏间质纤维化。

背景技术输尿管阻塞引起肾组织损伤，并可能不可逆地发展为肾纤维化，伴有肾小管细胞的萎缩和凋亡。本研究的目的是使用单侧输尿管梗阻（UUO）啮齿动物模型检查大黄酸对肾小管细胞凋亡以及肾纤维化的影响。方法通过输尿管结扎诱导UUO，然后对动物进行大黄酸或赋形剂处理。对照大鼠仅接受假手术。手术后1周收集肾组织以评估肾纤维化。结果UUO后，胶原蛋白I和α-平滑肌肌动蛋白（α-SMA）的表达以及肾小管凋亡和纤维化的严重程度随时间增加。大黄酸的治疗部分抑制了这种反应。肾间质纤维化与STAT3（信号转导和转录激活因子3）的磷酸化以及凋亡相关蛋白Bax和Bcl2的表达改变有关。大黄酸治疗也部分阻止了这些反应。结论这些发现表明，大黄酸在UUO啮齿动物模型中减轻了肾小管细胞的凋亡以及肾纤维化。此疗效可能是通过抑制STAT3磷酸化介导的。结论这些发现表明，大黄酸减轻了UUO啮齿动物模型中肾小管细胞的凋亡以及肾纤维化。此疗效可能是通过抑制STAT3磷酸化介导的。结论这些发现表明，大黄酸减轻了UUO啮齿动物模型中肾小管细胞的凋亡以及肾纤维化。此疗效可能是通过抑制STAT3磷酸化介导的。