Endoplasmic reticulum stress participates in uric acid-induced phenotypic transformation of renal tubular epithelial cells / 中华肾脏病杂志

ABSTRACT

Objective To explore the effect of endoplasmic reticulum stress (ER stress) in uric acid?induced phenotypic change in renal tubular epithelial cells (HK?2). Methods (1) HK?2 cells were cultured with 0, 75, 150, 225, 300 mg/L uric acid for 24 h in vitro. (2) The cells were divided into normal control group, ER stress inhibitor 4?PBA (5 μmol/L) group, uric acid (150 mg/L) group and 4?PBA+uric acid group for 24 h. Morphological changes of HK?2 cells were observed under inverted microscope. MTT assay was used to detect the proliferation of HK?2 cells treated with 150 mg/L uric acid for 24, 48 and 72 h. The protein expressions of α?smooth muscle actin (α?SMA), vimentin, snail, glucose regulated protein 78 (GRP78) and the phosphorylation of eukaryotic initiation factor 2α(p?eIF2α) in HK?2 cells were measured by Western blotting. Results Compared with the control group, HK?2 cells in uric acid groups (150, 225, 300 mg/L) showed fibroblast?like appearance. The protein expressions of α?SMA, vimentin, snail, GRP78 and p?eIF2α in 150 mg/L and 225 mg/L uric acid groups were higher than those in the control group (all P<0.05). The proliferation of HK?2 cells in 150 mg/L uric acid group was lower than that in control group at 48 and 72 h (all P<0.01). Compared with the uric acid group, the cell morphology in 4?PBA+uric acid group was improved, and the protein expressions ofα?SMA, vimentin, snail, GRP78 and p?eIF2α were decreased (all P<0.05). Conclusions Uric acid may induce the phenotype transformation of renal tubular epithelial cell, and ER stress is involved. 4?PBA may inhibit the uric acid?induced ER stress response and phenotypic transformation, and may be beneficial in attenuating uric acid?induced renal tubular damage.