RESUMO
Objective This study was designed to explore the effect of hyperglycemia on the expression of Toll-like receptor 4 (TLR4 ) in renal tubular epithelial cells and its significance in diabetic nephropathy. Methods In vitro cultured renal tubular epithelial cells ( NRK-52E) were divided into LG group (cultured in 5mmol / L glucose DMEM) and HC group (cultured in 25mmol / L glucose DMEM). Cells were harvested at different time points. Immunohistochemistry, Rt-PCR, Western Blot were used to detect TLR4 protein and mRNA expression, and the levels of IL-6 and TNF-α from the cell culture supernatant were determined by EL1SA assay. Results After 6 hours, there was increased expression TLR4 mRNA in HC group, which appeared to be maintained for 24 hours and began to decrease after 48 hours ( P < 0.05). TLR4 protein expression increased in HC group after 24 hours, and increased even further after 48 hours. Compared with LG groups, the difference had statistical significance ( P <0.05). In HG group, IL-6 and TNF-α expression in the supernatant from the NRK-52E culture were significantly increased ( P < 0.05) , and the expression of IL-6 and TNF-α was positive correlated with the expression of TLR4 protein ( r =0.799,0.820). Conclusion High glucose triggers an increase in expression of TLR4 in NRK-52E cells, itself leading to an increase in expression of inflammatory factors such as TNF-α and IL-6. In this way, TLR4 participates in the progress of diabetic nephropathy.
RESUMO
Objective To explore the expression and significance of nestin in renal tubular epithelial cells in hypercholesterolemic rats. Methods Dietary-induced hyperlipidemia were induced in female SD rats by given 4% cholesterol and 1% cholic acid diet for 16 weeks. Changes of serum lipid, urinary albumin, serum creatinine and renal interstitial pathological changes were assessed. The expression of nestin and a-smooth muscle actin (α-SMA) were detected by immunohistochemical stain. Results The serum levels of total cholesterol, low density lipoprotein, urinary albumin and serum creatinine were significantly increased in hyperlipidemia group, accompanied with renal interstitial injury and fibrosis. As time extended, the expression of nestin and a-SMA in renal tubular epithelial cells were increased significantly. There was positive correlation among the expression of nestin and total cholesterol, low density lipoprotein, urinary albumin and serum creatinine( r =0.963,0.830,0.944,0.706, P <0.01). Nestin also had a positive correlation with tubular-interstitial index ( r = 0. 974, P < 0. 01) and α-SMA ( r = 0. 804, P < 0. 01). Conclusion The increased expression of nestin may be associated with renal tubular-interstitial fibrosis and tubular epithelial myofibroblast transdifferentiation in hypercholesterolemic rats.