Zhang Fan, Zhou Xingcheng, Cui Daolin, Zhang Wei, Lai Jiao, Li Xiaoying, Ruan Yuanyuan, Xie Ying, Shi Mingjun, Xiao Ying, Wang Yuanyuan, Zhou Yuxia, Guo Bing
Department of Pathophysiology, Guizhou Medical University Guiyang 550025, China.
Key Laboratory of Pathogenesis and Drug Research of Common Chronic Diseases in Guizhou Province, Guizhou Medical University Guiyang 550025, China.
Int J Clin Exp Pathol. 2020 Dec 1;13(12):3021-3032. eCollection 2020.
To investigate the expression of Stim1 in the kidneys of mice with lupus, and the effect of Stim1 on the progression of renal interstitial fibrosis.
Mice (MRL/lpr) with spontaneous lupus nephritis (LN) and normal control mice (C57/BL) were selected. Immunohistochemistry and Masson staining were used to determine the degree of renal interstitial fibrosis in kidney tissues. The expression of Stim1 and fibronectin in tissues was measured by qRT-PCR, western blotting, and immunohistochemistry. Urine protein, blood urea nitrogen, and serum creatinine levels in the mice were analyzed, and Spearman analysis was conducted to determine the correlation with Stim1 expression levels. Mouse renal tubular epithelial cells (mRTECs) were chosen as the experimental objects. After various treatments, the cells were divided into the blank control group, lipopolysaccharide (LPS) treatment group, LPS+siRNA-NC group and LPS+siRNA-Stim1 group. Western blotting and immunofluorescence were used to measure epithelial-mesenchymal transition (EMT)-related protein levels.
There was significant interstitial fibrosis in the kidneys of LN mice. Compared with that in normal mice, the expression of Stim1 in the kidney tissues of LN mice was significantly increased, and Stim1 expression was positively correlated with fibronectin, urine protein, blood urea nitrogen and serum creatinine levels. LPS induced the expression of Stim1, fibronectin, and α-SMA in mRTECs and decreased the protein level of E-CA, while silencing Stim1 effectively alleviated the effects of LPS.
Stim1 is significantly increased in the kidneys of lupus mice, and it is possible to promote EMT in renal tubular epithelial cells and renal interstitial fibrosis by elevating fibronectin, which ultimately contributes to renal damage.
研究基质相互作用分子1（Stim1）在狼疮小鼠肾脏中的表达，以及Stim1对肾间质纤维化进展的影响。
选取自发性狼疮性肾炎（LN）小鼠（MRL/lpr）和正常对照小鼠（C57/BL）。采用免疫组织化学和Masson染色法测定肾组织肾间质纤维化程度。通过qRT-PCR、蛋白质免疫印迹法和免疫组织化学法检测组织中Stim1和纤连蛋白的表达。分析小鼠尿蛋白、血尿素氮和血清肌酐水平，并进行Spearman分析以确定与Stim1表达水平的相关性。选取小鼠肾小管上皮细胞（mRTECs）作为实验对象。经过各种处理后，将细胞分为空白对照组、脂多糖（LPS）处理组、LPS+siRNA-NC组和LPS+siRNA-Stim1组。采用蛋白质免疫印迹法和免疫荧光法检测上皮-间质转化（EMT）相关蛋白水平。
LN小鼠肾脏存在明显的间质纤维化。与正常小鼠相比，LN小鼠肾组织中Stim1的表达显著增加，且Stim1表达与纤连蛋白、尿蛋白、血尿素氮和血清肌酐水平呈正相关。LPS诱导mRTECs中Stim1、纤连蛋白和α-平滑肌肌动蛋白（α-SMA）的表达，并降低E-钙黏蛋白（E-CA）的蛋白水平，而沉默Stim1可有效减轻LPS的作用。
狼疮小鼠肾脏中Stim1显著升高，其可能通过升高纤连蛋白促进肾小管上皮细胞EMT和肾间质纤维化，最终导致肾损伤。
