关键词: 脂多糖, MEK/ERK1/2, U0126, 肾小管上皮细胞, NRK-52E

Abstract: 【Abstract】 Objective To investigate the role of LPS on proliferation of renal tubular epithelial cells NRK-52E and the implication of MEK/ERK1/2 in the process. Methods NRK-52E cells were cultured and challenged with LPS at different concentrations and for the indicated time courses. A specific MEK inhibitor, U0126, was used either alone or as a pretreatment followed by adding LPS to the medium to test the involvement of MEK/ERK1/2 in the proliferation of NRK-52E cells exposed to LPS. Cell proliferation was evaluated using cell counting kit-8 (CCK-8) reagents. The protein levels of ERK1/2, Akt, phosphorylated ERK1/2 and Akt (pERK1/2, pAkt), were detected by Western blot using specific antibodies. Results LPS inhibited NRK-52E cell proliferation at the concentrations from 0.1 to 1.0 mg·L-1 after treatment for 72 hours. NRK-52E cell proliferation was also inhibited by U0126 at the concentrations from 2.5 to 20 μM after treatment for 72 hours,without significant difference between the tested concentrations. LPS-induced suppression of NRK-52E cell proliferation was further aggravated by pretreatment with U0126. LPS induced phosphorylation of both ERK1/2 and Akt, peaked at 30 min. LPS-induced phosphorylation of ERK1/2 was blunted by U0126 at 72 h, while phosphorylation of Akt was elevated in cells treated with U0126 alone as well as in combination with LPS. Conclusion LPS suppressed NRK-52E cell proliferation, in which MEK/ERK1/2 might play a protective role.

Key words: LPS, MEK/ERK1/2, U0126, Renal tubular epithelial cell, NRK-52E