The regulatory roles of nuclear SM22 in smooth muscle phenotypic modulation

核SM22在平滑肌表型调节中的调节作用

• 批准号: 9766379
• 负责人: LI LI
• 金额: $ 51.45万
• 依托单位: WAYNE STATE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2018
• 资助国家: 美国
• 起止时间: 2018-09-01 至 2022-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9766379
• 关键词: Actin-Binding Protein; Actins; Acute; Address; Arteries; Binding; Bioinformatics; Blood Vessels; Cell Differentiation process; Cell Nucleus; Cell physiology; Chronic; Clinical; Competitive Binding; Cytoskeleton; Development; Disease; Down-Regulation; Drug Targeting; Epigenetic Process; Family; Feedback; Fibrosis; Future; Genes; Genetic; Genetic Transcription; Goals; In Vitro; Inflammation; Injury; Intervention; Knockout Mice; Knowledge; Lead; Mediating; Methods; Mission; Molecular; NF-kappa B; Nuclear; Nuclear Translocation; Pathogenesis; Pathogenicity; Pathologic; Pharmaceutical Preparations; Pharmacologic Substance; Pharmacology; Phenotype; Play; Process; Protein Deficiency; Proteins; Public Health; Publishing; Research; Role; Serum Response Factor; Smooth Muscle; Smooth Muscle Myocytes; Systems Biology; Testing; Therapeutic; Transgenic Mice; United States National Institutes of Health; Vascular Diseases; Vascular Smooth Muscle; Work; base; calponin; cell dedifferentiation; cofactor; dosage; improved; injured; innovation; member; myocardin; prevent; response; transcription factor; transcriptome

Project Summary: Vascular smooth muscle cell (SMC) phenotypic modulation plays critical roles in the pathogenesis of vascular diseases. SRF (Serum Response Factor) is a critical transcription factor that plays a central role in regulating gene transcription in SMC phenotypic modulation by competitively binding with Myocardin (the key differentiation regulator) and other key transcription regulators such as Elk and NF-kB. Extensive studies have characterized the mechanisms of actin-Myocardin interaction in SRF-mediated transcription, yet surprisingly the question of whether actin directly targets SRF to modulate SMC differentiation and phenotypic modulation has not been addressed. Downregulation of actin cytoskeleton proteins including actin and SM22 (an actin binding protein) has long been recognized as a marker of SMC phenotypic modulation and was until now regarded as a consequence of SMC dedifferentiation. However, we have now accumulated compelling evidence suggesting that SM22 but not actin can target SRF to regulate its transcriptional activities. The goal of this project is to characterize the molecular mechanisms of SM22 in coordinatively regulating the transcription of a variety of genes involved in SMC modulation from contractile phenotype to pathogenic phenotypes. Based on our published work and exciting preliminary results, we hypothesize that SM22 regulates SMC phenotypes as a transcription cofactor to modulate the interplay of SRF and other key transcription regulators for SMC differentiation and dedifferentiation in the vessel wall. We will take the system biology approach using integrated molecular, cellular, genetic, and bioinformatics methods to test this hypothesis. The Specific Aims are (i) to determine the molecular mechanisms whereby SM22 regulates the function of SRF in SMC phenotypic modulation in cultured SMCs. (ii) to determine the roles of SM22 in the pathogenesis of vascular wall remodeling in response to vascular injury using knockout and transgenic mice generated in our lab. Successful completion of this project will likely validate a new paradigm whereby actin cytoskeleton proteins actively participate in regulating smooth muscle phenotypic modulation during the pathogenesis of vascular diseases. We expect that the proposed studies will have the positive impact of identifying cytoskeleton proteins as a new class of targets for future pharmaceutical intervention.

项目摘要：血管平滑肌细胞 (SMC) 表型调节在 血管疾病的发病机制。 SRF（血清反应因子）是一种关键的转录因子，在 通过竞争性结合在 SMC 表型调节中调节基因转录的核心作用 心肌素（关键分化调节因子）和其他关键转录调节因子，例如 Elk 和 NF-kB。 广泛的研究已经表征了 SRF 介导的肌动蛋白-心肌素相互作用的机制 转录，但令人惊讶的是肌动蛋白是否直接靶向 SRF 来调节 SMC 分化的问题 并且表型调节尚未得到解决。肌动蛋白细胞骨架蛋白的下调包括 肌动蛋白和 SM22（肌动蛋白结合蛋白）长期以来被认为是 SMC 表型的标志物 调制，迄今为止被认为是 SMC 去分化的结果。然而，我们现在有 积累的令人信服的证据表明 SM22 而不是肌动蛋白可以靶向 SRF 来调节其 转录活动。该项目的目标是表征 SM22 的分子机制 协调调节参与 SMC 调节的多种基因的转录 表型到致病表型。根据我们已发表的工作和令人兴奋的初步结果，我们 假设 SM22 作为转录辅助因子调节 SMC 表型以调节 SRF 的相互作用 以及血管壁中 SMC 分化和去分化的其他关键转录调节因子。我们将 采用综合分子、细胞、遗传和生物信息学方法的系统生物学方法 检验这个假设。具体目标是 (i) 确定 SM22 的分子机制 在培养的 SMC 中调节 SRF 在 SMC 表型调节中的功能。 (ii) 确定角色 SM22 在响应血管损伤的血管壁重塑发病机制中的作用 我们实验室产生的转基因小鼠。该项目的成功完成可能会验证一个新的范式 肌动蛋白细胞骨架蛋白积极参与调节平滑肌表型调节 在血管疾病的发病过程中。我们期望拟议的研究将产生积极的结果 确定细胞骨架蛋白作为未来药物干预的一类新目标的影响。