ABSTRACT
Objective To observe functional changes of renal tubular epithelial cells stimulated by high mobility group protein box 1 (HMGB1) and associated mechanism.Methods Renal tubular epithelial cells (NRK52E) were divided into control group,HMGB1 group and HMGB1+ lipopolysaccharide from Rhodobactersphaeroides (LPS RS) group.Toll-like receptor 4 (TLR4) expression was detected by immunofluorescence and Western blotting.Apoptosis rate and cell cycle arrest were identified with flow cytometry.The activation of MAPK signaling pathway and NF-κB were detected by Western blotting.The IL-1,IL-6 and tissue inhibitor of metalloproteinases 2 (TIMP2) mRNA levels were measured by real-time PCR.The secretion levels of IL-1,IL-6 and TIMP2 were measured by protein chips assay.Results TLR4 was expressed by NRK52E cells.Compared with the control group,there were increased cell cycle G1 arrest,MAPK signaling pathway and NF-κB activation in HMGB1 group.Furthermore,IL-1,IL-6 and TIMP2 mRNA levels were increased and IL-1,IL-6 and TIMP2 were secreted by NRK52E when stimulated with HMGB1 (all P ＜0.05).However,effects mediated by HMGB1 stimulation could be inhibited by LPS RS (all P＜0.05).Conclusions Inflammatory activation of NRK52E cells can be mediated by the interaction of HMGB1 and TLR4.