The effect of hyperglycemia on the expression of Toll-like receptor 4 in renal tubular epithelial cells / 中国医师杂志

ABSTRACT

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.