Background. Endothelial cell senescence is one of the key mechanistic factors in the pathogenesis of atherosclerosis. In terms of molecules, the phosphatidylinositol 3-kinase/protein kinase B/endothelial nitric oxide synthase (PI3K/Akt/eNOS) signaling plays an important role in the prevention and control of endothelial cell senescence, while hydrogen sulfide (H2S) improves the induced precocious senescence of endothelial cells through the PI3K/Akt/eNOS pathway. Comparatively, replicative senescence in endothelial cells is more in line with the actual physiological changes of human aging. This study aims to investigate the mechanism by which H2S improves endothelial cell replicative senescence and the involvement of the PI3K/Akt/eNOS pathway. Methods. we established a model of replicative senescence in human umbilical vein endothelial cells (HUVECs) and explored the effect of 200 μmol/L sodium hydrosulfide (NaHS; a donor of H2S) on senescence, which was determined by cell morphology, the expression level of plasminogen activator inhibitor 1 (PAI-1), and the positive rate of senescence-associated β-galactosidase (SA-β-Gal) staining. Cell viability was detected by MTT assay to evaluate the effect of NaHS and the PI3K inhibitor, LY294002. Meanwhile, the protein expression of PI3K, Akt, p-Akt, and eNOS in endothelial cells of each group was detected by Western blot. Results. the replicative senescence model was established in HUVECs at the passage of 16 cumulative cell population doubling values (CPDL). Treatment with NaHS not only significantly reduced the expression of PAI-1 and the positive rate of SA-β-Gal in HUVEC’s replicative senescence model but also notably increased the expression of PI3K, p-Akt, p-eNOS, and the content of nitric oxide(NO). However, the effects of NaHS on the expression of the pathway and the content of NO in HUVECs were abolished when LY294002 specifically inhibited PI3K. Conclusion. NaHS improves the replicative senescence of HUVECs with the contribution of the PI3K/Akt/eNOS pathway.

中文翻译：

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外源性硫化氢激活 PI3K/Akt/eNOS 通路改善人脐静脉内皮细胞的复制衰老

背景。内皮细胞衰老是动脉粥样硬化发病机制中的关键机制因素之一。在分子方面，磷脂酰肌醇3-激酶/蛋白激酶B/内皮一氧化氮合酶（PI3K/Akt/eNOS）信号在内皮细胞衰老的预防和控制中起重要作用，而硫化氢（H2S）改善诱导的内皮细胞通过 PI3K/Akt/eNOS 通路发生早衰。相比之下，内皮细胞的复制性衰老更符合人体衰老的实际生理变化。本研究旨在探讨 H2S 改善内皮细胞复制衰老的机制以及 PI3K/Akt/eNOS 通路的参与。方法. 我们建立了人脐静脉内皮细胞 (HUVEC) 的复制衰老模型，并探讨了 200  μ mol/L 氢硫化钠（NaHS；H2S 的供体）对衰老的影响，这由细胞形态、纤溶酶原激活物抑制剂 1 (PAI-1) 和衰老相关β-半乳糖苷酶 (SA- β -Gal) 染色的阳性率。通过 MTT 测定法检测细胞活力，以评估 NaHS 和 PI3K 抑制剂 LY294002 的作用。同时，Western blot检测各组内皮细胞PI3K、Akt、p-Akt、eNOS蛋白表达。结果. 在经过 16 次累积细胞群倍增值 (CPDL) 后，在 HUVEC 中建立了复制衰老模型。NaHS处理不仅显着降低了HUVEC复制衰老模型中PAI-1的表达和SA- β -Gal的阳性率，而且显着增加了PI3K、p-Akt、p-eNOS的表达和一氧化氮的含量氧化物（NO）。然而，当 LY294002 特异性抑制 PI3K 时，NaHS 对该通路表达和 HUVEC 中 NO 含量的影响被消除。结论。NaHS 通过 PI3K/Akt/eNOS 通路改善 HUVEC 的复制衰老。