Hu Junping, Zhu Qing, Li Pin-Lan, Wang Weili, Yi Fan, Li Ningjun
Department of Pharmacology & Toxicology, Virginia Commonwealth University School of Medicine, Richmond, VA, USA.
Cell Physiol Biochem. 2015;35(5):1719-28. doi: 10.1159/000373984. Epub 2015 Mar 19.
Proteinuria-induced epithelial-mesenchymal transition (EMT) plays an important role in progressive renal tubulointerstitial fibrosis in chronic renal disease. Stem cell therapy has been used for different diseases. Stem cell conditioned culture media (SCM) exhibits similar beneficial effects as stem cell therapy. The present study tested the hypothesis that SCM inhibits albumin-induced EMT in cultured renal tubular cells.
Rat renal tubular cells were treated with/without albumin (20 µmg/ml) plus SCM or control cell media (CCM). EMT markers and inflammatory factors were measured by Western blot and fluorescent images.
Albumin induced EMT as shown by significant decreases in levels of epithelial marker E-cadherin, increases in mesenchymal markers fibroblast-specific protein 1 and α-smooth muscle actin, and elevations in collagen I. SCM inhibited all these changes. Meanwhile, albumin induced NF-κB translocation from cytosol into nucleus and that SCM blocked the nuclear translocation of NF-κB. Albumin also increased the levels of pro-inflammatory factor monocyte chemoattractant protein-1 (MCP)-1 by nearly 30 fold compared with control. SCM almost abolished albumin-induced increase of MCP-1.
These results suggest that SCM attenuated albumin-induced EMT in renal tubular cells via inhibiting activation of inflammatory factors, which may serve as a new therapeutic approach for chronic kidney diseases.
蛋白尿诱导的上皮-间质转化(EMT)在慢性肾脏病进行性肾小管间质纤维化中起重要作用。干细胞疗法已用于多种疾病。干细胞条件培养基(SCM)具有与干细胞疗法相似的有益作用。本研究检验了SCM抑制培养的肾小管细胞中白蛋白诱导的EMT这一假说。
用/不用白蛋白(20µmg/ml)加SCM或对照细胞培养基(CCM)处理大鼠肾小管细胞。通过蛋白质印迹法和荧光图像测量EMT标志物和炎症因子。
白蛋白诱导EMT,表现为上皮标志物E-钙黏蛋白水平显著降低、间质标志物成纤维细胞特异性蛋白1和α-平滑肌肌动蛋白增加以及I型胶原升高。SCM抑制了所有这些变化。同时,白蛋白诱导NF-κB从胞质溶胶转位至细胞核,而SCM阻断了NF-κB的核转位。与对照相比,白蛋白还使促炎因子单核细胞趋化蛋白-1(MCP)-1水平增加近30倍。SCM几乎消除了白蛋白诱导的MCP-1增加。
这些结果表明,SCM通过抑制炎症因子激活减轻了白蛋白诱导的肾小管细胞EMT,这可能成为慢性肾脏病的一种新治疗方法。