Biber John C, Sullivan Andra, Brazzo Joseph A, Heo Yuna, Tumenbayar Bat-Ider, Krajnik Amanda, Poppenberg Kerry E, Tutino Vincent M, Heo Su-Jin, Kolega John, Lee Kwonmoo, Bae Yongho
Department of Pathology and Anatomical Sciences, Jacobs School of Medicine and Biomedical Sciences, University at Buffalo, Buffalo, New York 14203, USA.
Department of Biomedical Engineering, School of Engineering and Applied Sciences, University at Buffalo, Buffalo, New York 14260, USA.
APL Bioeng. 2023 Oct 30;7(4):046108. doi: 10.1063/5.0150532. eCollection 2023 Dec.
Stiffened arteries are a pathology of atherosclerosis, hypertension, and coronary artery disease and a key risk factor for cardiovascular disease events. The increased stiffness of arteries triggers a phenotypic switch, hypermigration, and hyperproliferation of vascular smooth muscle cells (VSMCs), leading to neointimal hyperplasia and accelerated neointima formation. However, the mechanism underlying this trigger remains unknown. Our analyses of whole-transcriptome microarray data from mouse VSMCs cultured on stiff hydrogels simulating arterial pathology identified 623 genes that were significantly and differentially expressed (360 upregulated and 263 downregulated) relative to expression in VSMCs cultured on soft hydrogels. Functional enrichment and gene network analyses revealed that these stiffness-sensitive genes are linked to cell cycle progression and proliferation. Importantly, we found that survivin, an inhibitor of apoptosis protein, mediates stiffness-dependent cell cycle progression and proliferation as determined by gene network and pathway analyses, RT-qPCR, immunoblotting, and cell proliferation assays. Furthermore, we found that inhibition of cell cycle progression did not reduce survivin expression, suggesting that survivin functions as an upstream regulator of cell cycle progression and proliferation in response to ECM stiffness. Mechanistically, we found that the stiffness signal is mechanotransduced via the FAK-E2F1 signaling axis to regulate survivin expression, establishing a regulatory pathway for how the stiffness of the cellular microenvironment affects VSMC behaviors. Overall, our findings indicate that survivin is necessary for VSMC cycling and proliferation and plays a role in regulating stiffness-responsive phenotypes.
动脉僵硬度增加是动脉粥样硬化、高血压和冠状动脉疾病的一种病理表现，也是心血管疾病事件的关键危险因素。动脉僵硬度的增加会引发血管平滑肌细胞（VSMC）的表型转换、过度迁移和过度增殖，导致内膜增生和内膜形成加速。然而，这种触发机制尚不清楚。我们对在模拟动脉病理的刚性水凝胶上培养的小鼠VSMC的全转录组微阵列数据进行分析，发现相对于在软质水凝胶上培养的VSMC，有623个基因显著差异表达（360个上调，263个下调）。功能富集和基因网络分析表明，这些对硬度敏感的基因与细胞周期进程和增殖有关。重要的是，我们发现凋亡抑制蛋白survivin通过基因网络和通路分析、RT-qPCR、免疫印迹和细胞增殖试验，介导硬度依赖性细胞周期进程和增殖。此外，我们发现抑制细胞周期进程并不会降低survivin的表达，这表明survivin作为细胞周期进程和增殖的上游调节因子，对细胞外基质硬度作出反应。从机制上讲，我们发现硬度信号通过FAK-E2F1信号轴进行机械转导，以调节survivin的表达，从而建立了一条关于细胞微环境硬度如何影响VSMC行为的调节途径。总体而言，我们的研究结果表明，survivin是VSMC循环和增殖所必需的，并在调节硬度反应性表型中发挥作用。
