Targeting Resident Cardiac Fibroblast Subpopulations for Protection Against Fibrosis

针对常驻心脏成纤维细胞亚群以预防纤维化

• 批准号: 10544519
• 负责人: Taben M. Hale
• 金额: $ 59.62万
• 依托单位: UNIVERSITY OF ARIZONA
• 依托单位国家: 美国
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-01-01 至 2025-12-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10544519
• 关键词: Affect; Aftercare; American; Angiotensin II; Area; Automobile Driving; Cardiac; Cause of Death; Cells; Cellular Assay; Chromatin; Chromatin Structure; Cicatrix; Data; Development; Ensure; Enzyme Inhibition; Epigenetic Process; Exhibits; Extracellular Matrix; Fibroblasts; Fibrosis; Future; Gene Expression; Genes; HDAC2 gene; Heart; Heart Diseases; Heart failure; Histone Deacetylase; Hypertension; In Vitro; Inbred SHR Rats; Infusion procedures; Knockout Mice; Laboratory Finding; Left; Left ventricular structure; Mediating; Memory; Methodology; Mission; Modification; Myofibroblast; National Heart, Lung, and Blood Institute; Patients; Peptidyl-Dipeptidase A; Phenotype; Physiological; Physiology; Play; Population; Prevention; Process; Production; Proliferating; Protein Isoforms; Proteins; Public Health; Rattus; Research; Resistance; Risk Factors; Role; Signal Transduction; Small Interfering RNA; Testing; Tissues; Transcript; Transposase; Validation; Ventricular; Work; blood pressure reduction; chromatin remodeling; coronary fibrosis; experimental study; fascinate; hypertensive; in vivo; injured; interdisciplinary approach; novel therapeutic intervention; osteopontin; pressure; prevent; programs; response; single-cell RNA sequencing; targeted treatment; tool

PROJECT SUMMARY/ABSTRACT Hypertension stimulates cardiac fibroblast (CF) expansion, activation, and excess extracellular matrix (ECM) production. Although there are no approved treatments for cardiac fibrosis, angiotensin converting enzyme inhibition (ACEi) limits CF activation and ECM accumulation. Recent findings from the laboratory of the PI demonstrate that resident CFs, once considered functionally homogeneous, consist of physiologically distinct populations that differentiate to diverse phenotypes in response to pressure overload. The premise for this application is based on these findings in which hypertensive rats were transiently treated with an ACEi prior to single cell RNA sequencing on resident CFs. Pre-treatment with ACEi shifts CF subpopulations to generate homeostatic CFs with a reduced capacity for fibrosis. This effect persists after treatment is stopped, indicating memory is retained. The proposed studies will reveal the mechanisms by which CF subpopulations shift to determine how to reprogram CFs to display a homeostatic, less fibrogenic phenotype. Following ACEi, homeostatic CFs comprise the largest subpopulation of resident CFs and are the least fibrogenic. Trajectory analysis revealed a gateway CF subpopulation that is the immediate precursor to activated CFs, and this gateway cluster was the most depleted by ACEi. Gateway CFs were defined by high expression of Spp1, encoding for the protein osteopontin, which induces several pro-fibrotic genes and represents a critical target candidate to maintain the activated CF pool. ACEi altered expression of epigenetic genes, indicating changes in chromatin structure may drive the persistent shift from gateway to homeostatic CF subpopulations. These compelling preliminary results led to the central hypothesis: transient reduction in angiotensin II signaling alters CF memory to protect against left ventricle (LV) fibrosis by fibroblast subpopulation-specific reprogramming of chromatin structure to shift an osteopontin-producing gateway subpopulation toward a homeostatic subpopulation with low fibrogenic capacity. To test the hypothesis, the following specific aims are proposed: Aim 1) elucidate the degree to which reduction in angiotensin II signaling mediates the persistent shift in resident CF physiology that protects from future fibrosis; Aim 2) determine the impact of chromatin structural modification on shifting the gateway cluster toward the homeostatic cluster; and Aim 3) ascertain the degree to which reduction in osteopontin mediates the shift to a less fibrogenic phenotype. In this application, the research team uses a multidisciplinary approach employing in vivo and in vitro methodologies to test the hypothesis. Successful completion of these experiments will determine whether reduction in angiotensin II signaling mediates the expansion of a subset of homeostatic CFs that renders the LV resistant to fibrosis. It is expected that the key drivers regulating the shift from a gateway to a homeostatic subpopulation of CFs will be identified. Impact: These anticipated findings will have a positive impact in developing CF-targeted therapies for the treatment and prevention of fibrotic remodeling that underlies heart disease.

项目概要/摘要 高血压刺激心脏成纤维细胞 (CF) 扩张、活化和过量细胞外基质 (ECM) 生产。尽管尚无批准的治疗心脏纤维化的方法，但血管紧张素转换酶 抑制 (ACEi) 限制 CF 激活和 ECM 积累。 PI 实验室的最新发现 证明驻留 CF，曾经被认为功能同质，由生理上不同的组成 因压力超载而分化成不同表型的群体。这样做的前提是 该应用基于这些发现，其中高血压大鼠在治疗前短暂接受 ACEi 治疗 对常驻 CF 进行单细胞 RNA 测序。 ACEi 预处理可改变 CF 亚群以产生 纤维化能力降低的稳态 CF。这种效应在治疗停止后仍然存在，表明 记忆被保留。拟议的研究将揭示 CF 亚群转变为的机制 确定如何重新编程 CF 以显示稳态、纤维化较少的表型。继 ACEi 之后， 稳态 CF 包含最大的常驻 CF 亚群，并且纤维化程度最低。弹道 分析揭示了一个网关 CF 亚群，它是激活 CF 的直接前体，并且这 网关集群是 ACEi 消耗最严重的。 Gateway CF 由 Spp1 的高表达定义， 编码骨桥蛋白蛋白，可诱导多种促纤维化基因，是一个关键靶标 维护激活的 CF 池的候选者。 ACEi 改变了表观遗传基因的表达，表明发生了变化 染色质结构中的改变可能会驱动从门户向稳态 CF 亚群的持续转变。这些 令人信服的初步结果得出了中心假设：血管紧张素 II 信号传导的短暂减少会改变 CF记忆通过成纤维细胞亚群特异性重编程来防止左心室（LV）纤维化 染色质结构将产生骨桥蛋白的网关亚群转向稳态 纤维形成能力低的亚群。为了检验该假设，提出以下具体目标： 目标 1) 阐明血管紧张素 II 信号传导的减少在多大程度上介导了 常驻 CF 生理学可预防未来纤维化；目标 2) 确定染色质结构的影响 将网关集群转向稳态集群的修改；目标 3) 确定程度 骨桥蛋白的减少介导向纤维形成较少的表型的转变。在此应用中， 研究小组采用多学科方法，采用体内和体外方法来测试 假设。成功完成这些实验将决定血管紧张素 II 是否减少 信号传导介导稳态 CF 子集的扩张，使左心室抵抗纤维化。这是 预计调节CF从门户向稳态亚群转变的关键驱动因素将是 确定。影响：这些预期的发现将对开发 CF 靶向疗法产生积极影响 治疗和预防心脏病的纤维化重塑。