OBJECTIVETo study the effects of core proteoglycan on the transdifferentiation of human renal tubular epithelial cell induced by transforming growth factor beta1 (TGF-beta1) in vitro.

METHODThe cultured HK-2 cells were divided into six groups: A. negative control group; B. 10 ng/ml TGF-beta1 group; C. 10 ng/ml core proteoglycan treated group; D. 100 ng/ml core proteoglycan treated group; E. 10 ng/ml TGF-beta1 + 10 ng/ml core proteoglycan group; F. 10 ng/ml TGF-beta1 + 100 ng/ml core proteoglycan group. The changes in configuration of HK-2 cells were inspected 48 hours after adding the stimulating factor. At the same time, changes in mRNA of keratin, alpha-smooth muscle actin, vimentin were analyzed.

RESULTSCompared with group A, group B showed great changes in the morphology of cells, most cells converted into spindle shape, like fibroblast; groups E and F, especially group F showed significantly reduced spindle shape cells. Compared with group A, groups C and D had no significant changes in morphology of cells Compared with 10 ng/ml TGF-beta1 group and negative control, the mRNA expression of alpha-smooth muscle actin and vimentin had significant increase, but that of keratin reduced (P < 0.05). However, after combined treatment with TGF-beta1 and core proteoglycan, alpha-smooth muscle actin and vimentin expression were reduced significantly, while expression of keratin was up-regulated. Single core proteoglycan treated group and negative control group had no dramatic differences (P > 0.05).

CONCLUSIONTGF-beta1 can induce the transdifferentiation of human renal tubular epithelial cell and core proteoglycan has some inhibitory effect on transdifferentiation of human renal tubular epithelial cell induced by TGF-beta1 in vitro.