Targeting myofibroblast activation in chronic fibrotic disease

靶向慢性纤维化疾病中的肌成纤维细胞激活

• 批准号: 7824428
• 负责人: ARTHUR ROGER STRAUCH
• 金额: $ 1.58万
• 依托单位: OHIO STATE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-06-01 至 2011-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7824428
• 关键词: 1-Phosphatidylinositol 3-Kinase; Affect; Animal Model; Animal Welfare; Attenuated; Bibliography; Biochemical; Biology; COL1A2 gene; Cardiac; Cardiac Myocytes; Cell Line; Cell Nucleus; Cells; Chronic; Collagen; Collagen Gene; Collagen Type I; Complex; Complication; Contractile Proteins; Country; DNA; DNA binding protein B; Deposition; Disease; Dominant-Negative Mutation; Endothelin-1; Environment; Environmental Impact; Equipment; Feedback; Fibroblasts; Fibrosis; Gene Expression; Gene Expression Regulation; Genetic Transcription; Growth Factor; Heart; Hypertrophic Cicatrix; IACUC; In Vitro; Interleukin-13; International; Intervention; Lung; Manuscripts; Mediating; Messenger RNA; Modeling; Molecular; Mus; Muscle Cells; Myofibroblast; Nuclear; Outcome; Output; Peptides; Phosphotransferases; Play; Principal Investigator; Property; Proteins; Published Comment; Publishing; Pur-1 protein; RNA-Binding Proteins; Reading; Receptor Signaling; Regulation; Reperfusion Injury; Repressor Proteins; Research; Research Ethics Committees; Resources; Role; Signal Transduction; Smooth Muscle; Staging; Therapeutic; Thrombin; Time; Tissues; Transcription Coactivator; Transcription Regulatory Protein; Translations; Vascular Smooth Muscle; Vertebrates; Wound Healing; abstracting; alpha Actin; autocrine; base; cell type; cytokine; design; expiration; human subject; in vivo; inhibitor/antagonist; interstitial; interstitial cell; loss of function; novel; open wound; polypeptide; programs; promoter; research study; small hairpin RNA; small molecule

Chronic accumulation of myofibroblasts in healing wounds is associated with hypercontractility, excessive deposition of interstitial collagens, and destructive tissue remodeling. Vascular smooth muscle alpha-actin ((-SMA) is a contractile protein transiently expressed by differentiated myofibroblasts for generating tensile force required to close open wounds. In chronic fibrotic disease, myofibroblast differentiation is dysfunctional and we discovered that molecular signaling required for activation of both the (-SMA and type I collagen genes in these cells also provides negative feedback that could potentially limit the recruitment of hyperactive myofibroblasts during wound healing and destructive remodeling. Studies outlined in this proposal are expected to reveal novel forms of functional interplay of the DNA- and mRNA-binding proteins YB-1, Pur (, and Pur ( with the (-SMA and type I collagen promoters and clarify how these proteins are affected by pro- fibrotic agents such as TGF(1 and thrombin that, if unchecked, may cause myofibroblast progression to hypertrophic scarring. Experiments are designed to initiate, amplify, or attenuate myofibroblast differentiation to better understand strategies for controlling (-SMA and type I collagen gene output at the transcriptional and translation levels as well as reveal novel interventional strategies that might be useful for minimizing aberrant wound healing outcomes. Aim 1 will examine TGF(1-regulated interaction of YB-1 and Pur protein repressors with (-SMA and collagen promoter DNA and the transcriptional activators Sp1, SRF, and Smads 2,3, delineate regions of repressor polypeptide chains required for this functional interplay, and attempt to disrupt complex formation and disable pathobiologic myofibroblast differentiation using peptide decoys and small molecule pharmacologic inhibitors. Aim 2 will determine if thrombin potentiates myofibroblast differentiation at the level of translational control thus functioning as a TGF(1 supplement or instead antagonizes this growth factor by blocking transcription and myofibroblast recruitment by inducing the anti-fibrotic transcriptional regulatory protein, Egr-1. Aim 3 studies will explore alternative, Smad-independent mechanisms of myofibroblast differentiation and fibrosis. Loss-of-function approaches based on pharmacologic inhibition of TGF(1/Smad kinase- or phosphatidylinositol-3-kinase (PI3K)/Akt kinase signaling will be used to evaluate their possible suppressive effect on myofibroblast activation in vitro and cardiac fibrosis in mice after ischemia/reperfusion injury. The ability of TGF(1 and thrombin to exploit the unique DNA-, RNA-, and protein-binding properties of YB-1 and Pur proteins adds a new dynamic perspective to control of gene expression during myofibroblast differentiation that may reveal optimum strategies for therapeutic management of chronic fibrotic diseases.

愈合伤口中肌成纤维细胞的慢性积累与过度收缩、间质胶原过度沉积和破坏性组织重塑有关。血管平滑肌α-肌动蛋白（-SMA）是一种由分化的肌成纤维细胞瞬时表达的收缩蛋白，用于产生闭合开放性伤口所需的张力。在慢性纤维化疾病中，肌成纤维细胞分化功能障碍，我们发现这些细胞中β-SMA和I型胶原蛋白基因激活所需的分子信号传导也提供了负反馈，这可能会限制伤口愈合和破坏性重塑期间过度活跃的肌成纤维细胞的募集。本提案中概述的研究有望揭示DNA和mRNA结合蛋白YB-1、Pur β和Pur β与β-SMA和I型胶原启动子的功能性相互作用的新形式，并阐明这些蛋白如何受到促纤维化剂如TGF β 1和凝血酶的影响，如果不加抑制，可能导致肌成纤维细胞进展为肥大性瘢痕。实验旨在启动、扩增或减弱肌成纤维细胞分化，以更好地理解在转录和翻译水平控制β-SMA和I型胶原基因输出的策略，以及揭示可能有助于最大限度减少异常伤口愈合结果的新型干预策略。目的1将研究TGF β 1调节的YB-1和Pur蛋白阻遏物与β-SMA和胶原启动子DNA以及转录激活因子Sp1、SRF和Smads 2，3的相互作用，描绘这种功能相互作用所需的阻遏物多肽链区域，并尝试使用肽诱饵和小分子药理学抑制剂破坏复合物的形成并使病理生物学肌成纤维细胞分化失效。目的2将确定凝血酶是否在翻译控制水平上增强肌成纤维细胞分化，从而作为TGF β 1补充剂起作用，或者通过诱导抗纤维化转录调节蛋白Egr-1阻断转录和肌成纤维细胞募集来拮抗这种生长因子。目的3研究将探索肌成纤维细胞分化和纤维化的替代性、非Smad依赖性机制。基于TGF β 1/Smad激酶-或磷脂酰肌醇-3-激酶（PI 3 K）/Akt激酶信号传导的药理学抑制的功能丧失方法将用于评价它们对体外肌成纤维细胞活化和缺血/再灌注损伤后小鼠心脏纤维化的可能抑制作用。TGF β 1和凝血酶利用YB-1和Pur蛋白独特的DNA、RNA和蛋白质结合特性的能力为肌成纤维细胞分化过程中基因表达的控制提供了新的动态视角，这可能揭示慢性纤维化疾病治疗管理的最佳策略。