Department of Structural Cardiology, the First Affiliated Hospital of Xi'an Jiaotong University, Xi'an 710061, China.
Department of Graduate School, Xi'an Shiyou University, Xi'an 710065, China.
Acta Biochim Biophys Sin (Shanghai). 2022 Aug 25;54(8):1057-1067. doi: 10.3724/abbs.2022091.
WWP2 is a HECT-type E3 ubiquitin ligase that regulates various physiological and pathological activities by binding to different substrates, but its role in atherosclerosis (AS) remains largely unknown. The objective of the present study is to investigate the role and underlying molecular mechanisms of WWP2 in endothelial injury. We found that WWP2 expression is significantly decreased in Apolipoprotein E (ApoE) mice. Overexpression of WWP2 attenuates oxidative stress and inflammation in AS mice, while knockdown of has opposite effects. WWP2 overexpression alleviates oxidized low-density lipoprotein (ox-LDL)-induced human umbilical vein endothelial cell (HUVEC) injury, evidenced by the decreased oxidative stress levels and the secretion of inflammatory cytokines. Programmed cell death 4 (PDCD4) is identified as a potential substrate of WWP2. Co-immunoprecipitation (Co-IP) further demonstrates that WWP2 interacts with PDCD4, which is enhanced by ox-LDL treatment. Furthermore, the level of PDCD4 ubiquitination is significantly increased by WWP2 overexpression under the condition of MG132 treatment, while knockdown shows opposite results. Subsequently, rescue experiments demonstrate that knockdown further aggravates oxidative stress and inflammation in ox-LDL-treated HUVECs, while knockdown of alleviates this effect. Moreover, the use of sn-protoporphyrin (SnPP), an inhibitor of HO-1 pathway, confirms that PDCD4 enhances endothelial injury induced by ox-LDL through inhibiting HO-1 pathway. In conclusion, our results suggest that WWP2 protects against atherosclerosis progression via the PDCD4/HO-1 pathway, which may provide a novel treatment strategy for atherosclerosis.
WWP2 是一种 HECT 型 E3 泛素连接酶，通过与不同的底物结合，调节各种生理和病理活动，但它在动脉粥样硬化（AS）中的作用在很大程度上尚不清楚。本研究旨在探讨 WWP2 在血管内皮损伤中的作用及其潜在的分子机制。我们发现载脂蛋白 E（ApoE）-/-小鼠中 WWP2 的表达显著降低。过表达 WWP2 可减轻 AS 小鼠的氧化应激和炎症，而敲低 则有相反的作用。过表达 WWP2 可减轻氧化型低密度脂蛋白（ox-LDL）诱导的人脐静脉内皮细胞（HUVEC）损伤，表现为氧化应激水平降低和炎症细胞因子分泌减少。程序性细胞死亡因子 4（PDCD4）被鉴定为 WWP2 的潜在底物。共免疫沉淀（Co-IP）进一步表明 WWP2 与 PDCD4 相互作用，而 ox-LDL 处理可增强这种相互作用。此外，在 MG132 处理条件下，过表达 WWP2 可显著增加 PDCD4 的泛素化水平，而敲低则显示相反的结果。随后的挽救实验表明，在 ox-LDL 处理的 HUVEC 中，敲低 进一步加重氧化应激和炎症，而敲低 则可减轻这种作用。此外，使用 HO-1 途径抑制剂 sn-原卟啉（SnPP）证实，PDCD4 通过抑制 HO-1 途径增强 ox-LDL 诱导的内皮损伤。综上所述，我们的研究结果表明，WWP2 通过 PDCD4/HO-1 途径保护动脉粥样硬化进展，这可能为动脉粥样硬化提供一种新的治疗策略。
