Tianjin Institute of Cardiology, The Province and Ministry Co-sponsored Collaborative Innovation Center for Medical Epigenetics, State Key Laboratory of Experimental Hematology, National Clinical Research Center for Blood Diseases, Key Laboratory of Immune Microenvironment and Disease (Ministry of Education), The Second Hospital of Tianjin Medical University (Y.L., X.L., D.A.), Tianjin Medical University, China.
Department of Physiology and Pathophysiology (M.L., Y.Z., D.A.), Tianjin Medical University, China.
Circ Res. 2022 Mar 18;130(6):851-867. doi: 10.1161/CIRCRESAHA.121.320464. Epub 2022 Feb 18.
Metabolic syndrome is related to cardiovascular diseases, which is attributed in part, to arterial stiffness; however, the mechanisms remain unclear. The present study aimed to investigate the molecular mechanisms of metabolic syndrome-induced arterial stiffness and to identify new therapeutic targets.
Arterial stiffness was induced by high-fat/high-sucrose diet in mice, which was quantified by Doppler ultrasound. Four-dimensional label-free quantitative proteomic analysis, affinity purification and mass spectrometry, and immunoprecipitation and GST (glutathione S-transferase) pull-down experiments were performed to explore the mechanism of YAP (Yes-associated protein)-mediated TGF (transforming growth factor) β pathway activation.
YAP protein was upregulated in the aortic tunica media of mice fed a high-fat/high-sucrose diet for 2 weeks and precedes arterial stiffness. Smooth muscle cell-specific YAP knockdown attenuated high-fat/high-sucrose diet-induced arterial stiffness and activation of TGFβ-Smad2/3 signaling pathway in arteries. By contrast, mice exhibited exacerbated high-fat/high-sucrose diet-induced arterial stiffness and enhanced TGFβ-activated Smad2/3 phosphorylation in arteries. PPM1B (protein phosphatase, Mg/Mn-dependent 1B) was identified as a YAP-bound phosphatase that translocates into the nucleus to dephosphorylate Smads (mothers against decapentaplegic homologs) in response to TGFβ. This process was inhibited by YAP through removal of the K63-linked ubiquitin chain of PPM1B at K326.
This study provides a new mechanism by which smooth muscle cell YAP regulates the TGFβ pathway and a potential therapeutic target in metabolic syndrome-associated arterial stiffness.
代谢综合征与心血管疾病有关，部分归因于动脉僵硬；然而，其机制尚不清楚。本研究旨在探讨代谢综合征诱导的动脉僵硬的分子机制，并确定新的治疗靶点。
通过高脂肪/高蔗糖饮食在小鼠中诱导动脉僵硬，通过多普勒超声进行定量。进行了四维无标记定量蛋白质组学分析、亲和纯化和质谱分析、免疫沉淀和 GST（谷胱甘肽 S-转移酶）下拉实验，以探讨 YAP（Yes 相关蛋白）介导的 TGF（转化生长因子）β途径激活的机制。
在高脂/高蔗糖饮食喂养 2 周的小鼠主动脉中，YAP 蛋白上调，并先于动脉僵硬。平滑肌细胞特异性 YAP 敲低可减弱高脂肪/高蔗糖饮食诱导的动脉僵硬和动脉中 TGFβ-Smad2/3 信号通路的激活。相比之下，YAP 敲除小鼠表现出加剧的高脂肪/高蔗糖饮食诱导的动脉僵硬和增强的 TGFβ激活的 Smad2/3 磷酸化在动脉中。PPM1B（蛋白磷酸酶，Mg/Mn 依赖性 1B）被鉴定为 YAP 结合的磷酸酶，它响应 TGFβ 易位到核内去磷酸化 Smads（抑制多头畸形蛋白）。这一过程被 YAP 通过去除 PPM1B 的 K63 连接泛素链在 K326 处的泛素化而抑制。
本研究提供了平滑肌细胞 YAP 调节 TGFβ 途径的新机制，并为代谢综合征相关动脉僵硬提供了潜在的治疗靶点。
