Effects Of Albumin Overload On Epithelial-to-Mesenchymal Transition And Glucocorticoid Resistance In Human Renal Tubular Epithelial Cells

Objective:To study the effects of albumin overload on epithelialto -mesenchymal transition(EMT) and glucocorticoid resistance(P-gp, GRβ) in human renal tubular epithelial cells.Methods:Human renal tubular epithelial cells line HKC cells were cultured in medium with different concentration of human serum albumin (HSA)(5g/L,10g/L and 20g/L) for 48h,and cell proliferation was analyzed by MTT assay.Then HKC cells were cultured with 20g/L HSA for 48h,Cell morphology were analyzed by contrast phase microscope. The expressions of cytokeratin(CK),vimentin,p-glycoprotein(P-gp) and glucocorticoid receptorβ(GRβ) in HKC cells were measured by immunocytochemistry assay.An image analysis system was used in the immunocytochemistry process.Results:①Compared with the normal control group,HSA overload (5 g/L,10g/L or 20g/L) on HKC cells induced significantly cells proliferation(P＜0.05),and more significant in 20g/L HAS group(P＜0.05).②Morphotype of HKC cell changes when cultured with HSA overload for 48h,the HKC cells elongated from ovoid to fusiform,like fibroblast.③Normal HKC cells only expressed CK,without vimentin. When overloaded with HSA for 48h,the expression of CK decreased,and the expression of vimentin was increasing in HKC cells(P＜0.05).④Normal HKC cells expressed P-gp,but nearly no GRβexpression,the expressions of P-gp and GRβwas higher in HKC cells overloaded with HSA for 48h than that in normal(P＜0.05).⑤The level of P-gp expression positively correlated with GRβ(P＜0.01).The level of P-gp expression positively correlated with vimentin but negatively correlated with CK expression(P＜0.01 or P＜0.05).The level of GRβexpression negatively correlated with CK expression(P＜0.05),but no obviously correlated with vimentin(P＞0.05).Conclusions:①Albumin overload could induce cells proliferation and epithelial-to-mesenchymal transition(EMT) in HKC cells.②Albumin overload could increase expression of P-gp and GRβin HKC cells.③Up-regulation of P-gp and GRβexpression correlated with the degree of EMT in HKC cells.