Probucol inhibits JAK2−STAT pathway activation and protects human glomerular mesangial cells from tert-butyl hydroperoxide induced premature senescence

Human mesangial cells (HMCs) have a finite lifespan and eventually enter irreversible growth arrest known as cellular senescence, which is thought to contribute to kidney ageing and age-related kidney disorders such as chronic kidney disease. The JAK2−STAT pathway plays a pivotal role in transmitting cytokine signals, including cell proliferation, apoptosis, and differentiation, but whether it could regulate HMC senescence still remains to be explored. In our study, tert-butyl hydroperoxide (tBHP)-induced cells accelerated HMC senescence, as judged by increased senescence-associated β-galactosidase stained positive cells, morphological changes, and G0−G1 cell cycle arrest. STAT1 and STAT3 activity were increased in tBHP-induced cells. After tBHP treatment, Bcl-2 protein expression decreased and Bax protein expression increased. Blocking the JAK2−STAT pathway with AG490 and using probucol significantly inhibited the progression of HMC senescence. Bax protein expression decreased, but Bcl-2 protein expression increased after AG490 and probucol treatment. Our results indicated that the JAK2−STAT pathway might mediate tBHP-induced HMC senescence through the Bcl-2−Bax pathway, and that probucol could attenuate HMC senescence by regulating STATs.