Uric acid stimulates rat glomerular mesangial cells proliferation via activation of extracellular signal-regulated kinases / 中华肾脏病杂志

ABSTRACT

Objective To explore the effect of uric acid (UA) on the rat glomerular mesangial cells (GMCs) and its possible mechanism in vitro. Methods Cultured rat GMCs were treated with various concentrations of UA (50 μmol/L, 100 μmol/L, 300 μmol/L) in the presence or absence of U0126, apocynin, rotenone. The incorporation of 3H-thymidine (3H-TdR) and cell counting were used to measure GMCs proliferation. GMCs cell-cycle was analyzed by flow cytometry. CyclinD1 and cyclin A2 expression were determined by real-time PCR and Western blotting analysis. ERK1/2 phosphorylation was detected by Western blotting. Reactive oxygen species (ROS) was measured by 2, 7-dichlorofluorescein diacetate (DCFDA) fluorescence. Results (1) Uric acid increased GMCs proliferation in dose-dependent manner compared with the control groups, as assessed by 3H-TdR incorporation and cell counting. GMCs proliferation induced by 300 μmol/L uric acid was increased by more than 1.5-fold assessed by both of the methods. (2) Uric acid decreased cell number in G1/G0 phase and increased cell number in S phase in dosedependent manner, as assessed by flow cytometry. (3) Uric acid iuduced cyclin D1 and cyclin A2 expression in dose-dependent manner. (4)Uric acid increased pospho-ERK1/2 in dose-dependent manner and ERK1/2 specific inhibitor U0126 could suppress uric acid-induced cell proliferation.The inhibition percentage of U0126 was 22% and 31% assassed by cell counting and 3H-TdR incorporation, respectively. (5) Uric acid increased ROS production in dose-dependent manner.NADPH oxidase inhibitor apocynin could also significantly inhibit uric acid-induced ROS production, ERK phosphorylation and cell proliferation. In contrast, rotenone had no effect on them.Conclusion Uric acid can stimulate rat GMCs proliferation, partially by the activation of ERK pathway via NADPH oxidase-derived ROS generation.