Effects of saponin from the seed of Litchi chinensis Sonn on TGF-β1, FN and SOCS-1 in renal tubular epithelial cells under high glucose

摘要

目的:探讨荔枝核皂苷对高糖培养的人肾小管上皮细胞凋亡的影响.方法:用含30mmol/L葡萄糖的DMEM/F12培养基培养HKC细胞,加入或者不加入SLS干预.空白对照组加入等体积的含5.5mmol/L葡萄糖的DMEM/F12培养基.用ELISA检测细胞转化生长因子β1(TGF-β1)、纤维连接素(FN)的分泌,用Annexin V-FITC/PI双染法检测细胞凋亡,用Western blot检测细胞因子信号转导抑制因子-1(SOCS-1)的表达.结果:ELISA结果显示,SLS可以降低TGF-β1、FN的分泌,与30mmol/L的葡萄糖组相比具有显著性差异(P<0.01).Annexin V-FITC/PI双染法结果显示,与正常组比较,30mmol/L的葡萄糖组细胞凋亡明显增加(P<0.01);SLS各剂量组明显降低HKC细胞的凋亡(P<0.01),其SLS浓度与HKC细胞凋亡率呈负相关.Western blot结果显示:与空白对照组相比,30mmol/L葡萄糖组SOCS-1的蛋白表达量升高(P<0.01),SLS能显著降低SOCS-1蛋白的表达(P<0.01).结论:SLS可以降低HKC细胞TGF-β1、FN的分泌,并明显降低HKC细胞的凋亡,从而延缓与减轻肾小球硬化.%Objective:To investigate the effect of saponin from the seed of Litchi chinensis Sonn (SLS) on the growth and apoptosis of human kidney epithelial cells (HKC) cultured in high glucose. Methods:HKC were cultured in DMEM/F12 medium supplemented with 30 mmol/L glucose and treated with or without SLS. In the normal group, isometric DMEM/F12 medium with 5.5mmol/L glucose was added. The secretion of TGF-β1 and fibronectin (FN) were detected by ELISA. Cell apoptosis was detected by the method of Annexin V-FITC/PI double staining. Western blot was used to detect the level of suppressor of cytokine signaling-1 (SOCS-1). Results:The result of ELISA showed that the secretion of TGF-β1 and FN was decreased in SLS groups compared with those in 30 mmol/L glucose treated group (P<0.05). There were more cells apoptosis in 30 mmol/L glucose treated group than that in the normal group (P<0.01). Compared with the 30 mmol/L glucose treated group, the apoptosis of HKC were significantly decreased in SLS groups (P< 0.01). Western blot showed that the level of SOCS-1 in high glucose+SLS group was decreased (P<0.01), compared with the high glucose group. Conclusion: SLS can reduce the secretion of TGF-β1 and FN in HKC by reducing the deposition of extracellular matrix. SLS also significantly reduced the apoptosis of HKC by inhibiting the level of SOCS-1. These results suggest the roles of SLS in preventing the progress of glomerular sclerosis.