Department of Endocrinology, Guangdong General Hospital, Guangdong Academy of Medical Sciences, Guangdong Geriatrics Institute, Guangzhou, Guangdong 510080, P.R. China.
Department of Pediatrics, Huangpu Division of the First Affiliated Hospital, Sun Yat‑sen University, Guangzhou, Guangdong 510700, P.R. China.
Int J Mol Med. 2018 Mar;41(3):1477-1486. doi: 10.3892/ijmm.2017.3330. Epub 2017 Dec 19.
Hyperglycemia is a key factor in the development of diabetic complications, including the processes of atherosclerosis. Receptor‑interacting protein 3 (RIP3), a mediator of necroptosis, is implicated in atherosclerosis development. Additionally, hydrogen sulfide (H2S) protects the vascular endothelium against hyperglycemia‑induced injury and attenuates atherosclerosis. On the basis of these findings, the present study aimed to confirm the hypothesis that necroptosis mediates high glucose (HG)‑induced injury in human umbilical vein endothelial cells (HUVECs), and that the inhibition of necroptosis contributes to the protective effect of exogenous H2S against this injury. The results revealed that exposure of HUVECs to 40 mM HG markedly enhanced the expression level of RIP3, along with multiple injuries, including a decrease in cell viability, an increase in the number of apoptotic cells, an increase in the expression level of cleaved caspase‑3, generation of reactive oxygen species (ROS), as well as dissipation of the mitochondrial membrane potential (MMP). Treatment of the cells with sodium hydrogen sulfide (NaHS; a donor of H2S) prior to exposure to HG significantly attenuated the increased RIP3 expression and the aforementioned injuries by HG. Notably, treatment of cells with necrostatin‑1 (Nec‑1), an inhibitor of necroptosis, prior to exposure to HG ameliorated the HG‑induced injuries, leading to a decrease in ROS generation and a loss of MMP. However, pre‑treatment of the cells with Nec‑1 enhanced the HG‑induced increase in the expression levels of cleaved caspases‑3 and ‑9. By contrast, pre‑treatment with Z‑VAD‑FMK, a pan ‑caspase inhibitor, promoted the increased expression of RIP3 by HG. Taken together, the findings of the present study have demonstrated, to the best of our knowledge for the first time, that exogenous H2S protects HUVECs against HG‑induced injury through inhibiting necroptosis. The present study has also provided novel evidence that there is a negative interaction between necroptosis and apoptosis in the HG‑treated HUVECs.
高血糖是糖尿病并发症发展的一个关键因素，包括动脉粥样硬化的过程。受体相互作用蛋白 3（RIP3）是一种坏死性凋亡的介体，与动脉粥样硬化的发展有关。此外，硫化氢（H2S）可保护血管内皮细胞免受高血糖诱导的损伤，并减轻动脉粥样硬化。基于这些发现，本研究旨在证实以下假说，即坏死性凋亡介导高葡萄糖（HG）诱导的人脐静脉内皮细胞（HUVEC）损伤，并且坏死性凋亡的抑制有助于外源性 H2S 对这种损伤的保护作用。结果显示，将 HUVEC 暴露于 40mM HG 可显著增强 RIP3 的表达水平，同时伴随着多种损伤，包括细胞活力降低、凋亡细胞数量增加、cleaved caspase-3 表达水平增加、活性氧（ROS）生成增加以及线粒体膜电位（MMP）耗散。在将 HUVEC 暴露于 HG 之前用硫氢化钠（NaHS；H2S 的供体）处理细胞可显著减轻 HG 引起的 RIP3 表达增加和上述损伤。值得注意的是，在将 HUVEC 暴露于 HG 之前用坏死性凋亡抑制剂 necrostatin-1（Nec-1）处理细胞可改善 HG 诱导的损伤，导致 ROS 生成减少和 MMP 丧失。然而，用 Nec-1 预处理细胞会增强 HG 诱导的 cleaved caspases-3 和 -9 的表达增加。相比之下，用 pan-caspase 抑制剂 Z-VAD-FMK 预处理可促进 HG 引起的 RIP3 表达增加。综上所述，本研究结果首次表明，外源性 H2S 通过抑制坏死性凋亡来保护 HUVEC 免受 HG 诱导的损伤。本研究还提供了新的证据，表明在 HG 处理的 HUVEC 中，坏死性凋亡和细胞凋亡之间存在负相互作用。
