Novel Role of MAPK14 in Regulation of VSMC Contractile Phenotype

MAPK14 在 VSMC 收缩表型调节中的新作用

• 批准号: 8670325
• 负责人: Xiaochun Long
• 金额: $ 39.5万
• 依托单位: ALBANY MEDICAL COLLEGE
• 依托单位国家: 美国
• 财政年份: 2014
• 资助国家: 美国
• 起止时间: 2014-04-01 至 2019-01-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8670325
• 关键词: Address; Affect; Aorta; Arterial Disorder; Biological Assay; Blood Pressure; Blood Vessels; Carotid Arteries; Cell Differentiation process; Chemicals; Data; Development; Disease; Disease model; Endothelial Cells; Exhibits; Family; Functional RNA; Gene Expression; Genes; Human; In Vitro; Injury; Knockout Mice; Lesion; Ligation; Link; MAPK14 gene; Mediating; Modeling; Molecular; Mus; Nuclear Translocation; Pathway interactions; Phenotype; Phosphorylation; Phosphotransferases; Process; Protein Isoforms; RNA Interference; Regulation; Reporter; Resistance; Role; SB 203580; Serum Response Factor; Signal Pathway; Signal Transduction; Signaling Molecule; Site; Smooth Muscle Myocytes; Subfamily lentivirinae; Therapeutic; Transducers; Transgenic Mice; Vascular Diseases; Veins; Work; attenuation; base; combat; design; in vivo; inhibitor/antagonist; innovation; insight; knock-down; mouse model; myocardin; novel; novel strategies; novel therapeutics; programs; public health relevance

DESCRIPTION (provided by applicant): Vascular smooth muscle cells (VSMC) exhibit phenotypic plasticity that contributes to human vascular disease. Serum response factor (SRF) and the Myocardin family of coactivators (e.g., MRTFA) have emerged as key inducers of the VSMC contractile phenotype. Although much work exists on SRF-MRTFA-dependent gene expression, a critical gap exists with respect to our understanding of signaling pathways that converge upon SRF-MRTFA to negatively affect VSMC gene expression. We and others have proposed p38MAPK signaling as a critical signal transducer of TGF¿1-induced VSMC differentiation; however, all studies to date have relied upon the exclusive use of chemical inhibitors of p38MAPK (e.g., SB203580). Since such inhibitors likely have unknown effects un-related to p38MAPK, we performed small interference RNA knockdown studies of p38MAPK¿ (MAPK14), the major isoform of p38MAPK in VSMC targeted by SB compounds. Rather than inhibiting VSMC gene expression, as predicted by prior studies using SB compounds, we found knockdown of MAPK14 stimulates VSMC contractile gene expression. Using several well-defined vascular injury models, we found total and phosphorylated MAPK14 are enriched in the neointima of the vessel wall where phenotypically altered VSMC reside suggesting MAPK14 expression is somehow linked to the synthetic VSMC phenotype. New, exciting data show VSMC-specific Mapk14 knockout mice exhibit induced VSMC contractile gene expression and are completely resistant to injury-induced neointimal formation. Mechanistically, we have found that MAPK14 regulates MRTFA nucleo-cytoplasmic shuttling, a critical determinant of SRF-dependent VSMC contractile gene expression. Our most recent finding reveals depletion of MAPK14 up-regulates a novel Smooth muscle and Endothelial cell enriched long Non-Coding RNA (SENCR), that exerts positive effects on the VSMC contractile phenotype. Based on these findings, we have formulated the global hypothesis that MAPK14 antagonizes VSMC contractile phenotype and promotes vascular disease through dysregu- lation of MRTFA nuclear translocation and inhibition of SENCR. Three inter-related specific aims are pro- posed to address this hypothesis using novel mouse models and innovative concepts. In Aim 1, we will elucidate the role of MAPK14 in VSMC phenotypic plasticity leading to vascular disease. In Aim 2, we will elucidate the integrative role of MAPK14 and MRTFA in regulating VSMC differentiation. In Aim 3, we will elucidate the regulation and function of MAPK14-dependent inhibition of SENCR in VSMC. Collectively, these studies will illuminate an important and heretofore unrecognized role for MAPK14 in negatively regulating VSMC differentiation, thus providing fresh insight into the molecular control of VSMC phenotype. These studies also challenge the paradigm of p38MAPK as a pro-VSMC differentiation signaling pathway and will link this pathway to the antagonism of two key downstream targets (MRTFA and SENCR). Information gained through these studies has intriguing therapeutic potential for designing novel strategies to combat vascular diseases.

描述（由申请人提供）：血管平滑肌细胞（VSMC）表现出导致人类血管疾病的表型可塑性。血清反应因子 (SRF) 和心肌素家族共激活剂（例如 MRTFA）已成为 VSMC 收缩表型的关键诱导剂。尽管在 SRF-MRTFA 依赖性基因表达方面存在大量工作，但我们对汇聚 SRF-MRTFA 对 VSMC 基因表达产生负面影响的信号通路的理解存在关键差距。我们和其他人提出 p38MAPK 信号传导作为 TGF¿1 诱导的 VSMC 分化的关键信号转导器；然而，迄今为止的所有研究都依赖于仅使用 p38MAPK 化学抑制剂（例如 SB203580）。由于此类抑制剂可能具有与 p38MAPK 无关的未知作用，因此我们对 p38MAPK (MAPK14) 进行了小干扰 RNA 敲低研究，p38MAPK 是 SB 化合物靶向的 VSMC 中 p38MAPK 的主要亚型。我们发现 MAPK14 的敲除会刺激 VSMC 收缩基因表达，而不是像之前使用 SB 化合物的研究所预测的那样抑制 VSMC 基因表达。使用几个明确的血管损伤模型，我们发现总的和磷酸化的 MAPK14 在血管壁的新内膜中富集，其中表型改变的 VSMC 存在，这表明 MAPK14 的表达在某种程度上与合成的 VSMC 表型相关。令人兴奋的新数据显示，VSMC 特异性 Mapk14 敲除小鼠表现出诱导的 VSMC 收缩基因表达，并且完全抵抗损伤诱导的新内膜形成。从机制上讲，我们发现 MAPK14 调节 MRTFA 核质穿梭，这是 SRF 依赖性 VSMC 收缩基因表达的关键决定因素。我们最新的发现表明，MAPK14 的缺失会上调一种新型平滑肌和内皮细胞富集的长非编码 RNA (SENCR)，这对 VSMC 收缩表型产生积极影响。基于这些发现，我们提出了总体假设：MAPK14 拮抗 VSMC 收缩表型，并通过 MRTFA 核易位失调和 SENCR 抑制促进血管疾病。提出了三个相互关联的具体目标，以使用新颖的小鼠模型和创新概念来解决这一假设。在目标 1 中，我们将阐明 MAPK14 在导致血管疾病的 VSMC 表型可塑性中的作用。在目标 2 中，我们将阐明 MAPK14 和 MRTFA 在调节 VSMC 分化中的综合作用。在目标 3 中，我们将阐明 VSMC 中 MAPK14 依赖性 SENCR 抑制的调节和功能。总的来说，这些研究将阐明 MAPK14 在负向调节 VSMC 分化中的重要且迄今为止未被认识的作用，从而为 VSMC 表型的分子控制提供新的见解。这些研究还挑战了 p38MAPK 作为前 VSMC 分化信号通路的范式，并将该通路与两个关键下游靶点（MRTFA 和 SENCR）的拮抗作用联系起来。通过这些研究获得的信息对于设计对抗血管疾病的新策略具有令人着迷的治疗潜力。