硫化氢通过抑制蛋白激酶B过度磷酸化延缓内皮细胞衰老

Hydrogen sulfide attenuates endothelial cell senescence via inhibiting over-phosphorylation of protein kinase B

目的:探讨外源性硫化氢对过氧化氢诱导的人脐静脉内皮细胞(HUVECs)衰老的作用及可能机制。方法:建立过氧化氢诱导的HUVECs早熟型衰老模型,Western blot检测相关参数验证硫化氢对衰老的作用。结果:HUVECs经60μmol/L过氧化氢处理后,衰老相关β-半乳糖苷酶(SA-β-Gal)染色阳性细胞比例增加,血浆纤溶酶原激活物抑制剂1(PAI-1)表达明显增高,蛋白激酶B磷酸化水平升高;与过氧化氢组比较,100μmol/L硫氢化钠(硫化氢供体)处理组SA-β-Gal染色阳性细胞比例及PAI-1蛋白表达显著下降,蛋白激酶B磷酸化水平降低;同样,与过氧化氢组比较,30μmol/L LY294002(蛋白激酶B抑制剂)处理组,SA-β-Gal染色阳性细胞比例表达显著下降。结论:硫化氢通过抑制蛋白激酶B的过度磷酸化而延缓过氧化氢诱导的HUVECs衰老。

AIM:To explore the effect of hydrogen sulfide on the senescence of human umbilical vein endothelial cells(HUVECs)induced by hydrogen peroxide(H2O2)and the possibly involved mechanism.METHODS:Senescence model was established by treating HUVECs with H2O2 at 60μmol/L for 1 h and then cultured for 24 h.The several parameters were detected to demonstrate the effect of hydrogen sulfide on senescence by Western blot.RESULTS:In the cells treated with H2O2,a larger proportion of cells were stained withβ-galactosidase(SA-β-Gal),and the protein expression of plasminogen activator inhibitor 1(PAI-1)was dramatically increased(P<0.05).The less SA-β-Gal positive cells and decreased protein of PAI-1 were detected when the cells were pretreated with 100μmol/L sodium hydrosulfide(NaHS).Furthermore,NaHS treatment inhibited the phosphorylation of protein kinase B(PKB/Akt).Meanwhile,LY294002,the specific inhibitor of Akt,was also able to reverse the cellular senescence induced by H2O2 in HUVECs.CONCLUSION:Exogenous hydrogen sulfide prevents HUVECs against H2O2-induced senescence partially via the inhibition of Akt over-phosphorylation.