Targeting Matrix Stiffness in Lung Fibrosis Associated with Aging

针对与衰老相关的肺纤维化的基质硬度

• 批准号: 9767855
• 负责人: YONG ZHOU
• 金额: $ 50.8万
• 依托单位: UNIVERSITY OF ALABAMA AT BIRMINGHAM
• 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 2022-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9767855
• 关键词: Acetylation; Acids; Adult Respiratory Distress Syndrome; Advanced Glycosylation End Products; Affect; Aging; Animals; Apoptosis; Apoptotic; Bleomycin; Blood; CD95 Antigens; CX3CL1 gene; Cells; Cessation of life; Collagen; Collagen Fiber; Death Domain; Development; Diabetes Mellitus; Digestion; Double Minutes; Eating; Effector Cell; Elderly; Extracellular Matrix; Feedback; Fibrosis; Genes; Goals; Human; Impairment; Infiltration; Injury; Interstitial Collagenase; Lesion; Lung; Lung diseases; Mechanics; Mediating; Molecular; Mus; Myofibroblast; Oral Administration; Pathway interactions; Patients; Phagocytosis; Production; Pulmonary Fibrosis; Reporting; Repression; Resistance; Resolution; Risk Factors; Role; Signal Transduction; Slice; Solubility; Structure of parenchyma of lung; TP53 gene; Testing; Tissues; aged; chemokine; crosslink; effective therapy; glycation; idiopathic pulmonary fibrosis; immunogenic; inhibitor/antagonist; macrophage; mouse model; novel; novel therapeutic intervention; polyacrylamide hydrogels; programs; receptor; recruit; treatment strategy

Aging is associated with the development of nonresolving pulmonary fibrosis in both human and experimental animals. Stiffening of the extracellular matrix (ECM) is a prominent feature of lung fibrosis. Interactions between stiffened fibrotic ECM and effector cells of tissue fibrosis, known as myofibroblasts (MFBs), provide a feedforward mechanism that sustains/amplifies lung fibrosis. Targeting matrix stiffness to break the profibrotic feedback loop represents a promising strategy for treatment of persistent/progressive lung fibrosis. The current study aimed to test a proof-of-concept of matrix de-stiffening therapy against lung fibrosis associated with aging. Previous studies have shown that the formation of advanced glycation end-products (AGEs) accumulates with aging and occurs at an accelerated rate in lung fibrosis. The ECM, in particular collagen matrix, is highly susceptible to glycation due to its slow turnover rate. AGEs drives nonenzymatic crosslinking of collagen fibers. The formation of intra- and inter-molecular collagen crosslinks is a crucial factor that stiffens the ECM. In preliminary studies, we targeted AGE-mediated glycation crosslinking for matrix de-stiffening and potential anti-fibrotic therapy against aging-associated nonresolving lung fibrosis in a bleomycin injury-induced mouse model. We found that anti-AGE treatment reduces the amount of crosslinked lung collagens, decreases lung stiffness, and promotes the resolution of experimental lung fibrosis in aged mice. We identified mouse double minute 4 (MDM4), a major endogenous inhibitor of p53, as a matrix stiffness-regulated mechanosensitive molecule. Reducing matrix stiffness downregulates MDM4 expression, resulting in p53 de- repression/activation. Gain of p53 function sensitizes lung MFBs to apoptosis by upregulating Fas and induces immunogenic conversion of MFBs that release CX3CL1 chemokine to recruit macrophages and express Death Domain 1α (DD1α) engulfment receptor to facilitate macrophage-mediated phagocytosis of apoptotic MFBs. These findings suggest that matrix de-stiffening by targeting nonenzymatic AGE crosslinking activates a fibrosis resolution pathway. The central hypothesis of the current project is that matrix de-stiffening sensing by MDM4 promotes lung MFB clearance and the reversal of aging-associated nonresolving pulmonary fibrosis. Specific aims are: (1) determine the mechanisms by which matrix stiffness regulates MDM4 expression; (2) determine whether matrix stiffness sensing by MDM4 mediates the clearance of lung MFBs by activation of a p53-directed gene program involving Fas, CX3CL1 and DD1α; and (3) determine the role of mechanosensitive MDM4 in the fate decisions of lung MFBs and the reversal of aging-associated pulmonary fibrosis in mice. The proposed study will elucidate cellular and molecular mechanisms involved in the reversal of aging-associated lung fibrosis by targeting nonenzymatic AGE crosslinking. The hypothesis, if proven, will establish a proof-of- concept of matrix de-stiffening therapy against aging-associated nonresolving pulmonary fibrosis.

在人类和实验动物中，衰老与非消退性肺纤维化的发生有关。 动物细胞外基质（ECM）的硬化是肺纤维化的显著特征。相互作用 在硬化的纤维化ECM和组织纤维化的效应细胞（称为肌成纤维细胞（MFB））之间， 维持/放大肺纤维化的前馈机制。靶向基质硬度以破坏促纤维化 反馈回路代表了用于治疗持续性/进行性肺纤维化的有前景的策略。的 目前的研究旨在测试针对肺纤维化相关的基质去硬化疗法的概念验证。 随着年龄的增长。以往的研究表明，晚期糖基化终产物（AGEs）的形成， 随着年龄的增长而积累，并在肺纤维化中加速发生。ECM，特别是胶原蛋白， 基质，由于其缓慢的周转率，对糖化高度敏感。AGEs驱动非酶交联 胶原纤维。分子内和分子间胶原交联的形成是硬化的关键因素， ECM。在初步研究中，我们靶向AGE介导的糖基化交联， 博来霉素损伤诱导的老年性肺纤维化的潜在抗纤维化治疗 小鼠模型我们发现抗AGE治疗减少了交联的肺胶原的量， 降低肺硬度，并促进老年小鼠实验性肺纤维化的消退。我们确定 小鼠双微体4（MDM4），一种主要的内源性p53抑制剂，作为基质硬度调节因子， 机械敏感分子降低基质硬度下调MDM4表达，导致p53去表达。 抑制/激活。p53功能的获得通过上调Fas使肺MFB对凋亡敏感，并诱导 释放CX3CL1趋化因子以募集巨噬细胞并表达死亡MFB的免疫原性转化 结构域1 α（DD 1 α）吞噬受体促进巨噬细胞介导的凋亡MFB的吞噬作用。 这些发现表明，通过靶向非酶促AGE交联的基质去硬化激活了一种新的细胞因子， 纤维化消退途径。当前项目的中心假设是，通过 MDM4促进肺MFB清除和逆转衰老相关的非消退性肺纤维化。 具体目标是：（1）确定基质硬度调节MDM4表达的机制;（2） 确定通过MDM4的基质硬度感测是否通过激活MFB介导肺MFB的清除， p53指导的基因程序涉及Fas、CX3CL1和DD 1 α;（3）确定机械敏感性 MDM4在小鼠肺MFB命运决定和衰老相关肺纤维化逆转中的作用的 这项研究将阐明逆转衰老相关的细胞和分子机制。 通过靶向非酶促AGE交联实现肺纤维化。假设，如果被证明，将建立一个证据- 基质去硬化治疗抗衰老相关的非消退性肺纤维化的概念。