Stress-induced loss of BIV-spectrin regulates cardiac fibroblast function and long-range communication

压力引起的 BIV 血影蛋白损失调节心脏成纤维细胞功能和远程通讯

• 批准号: 10751644
• 负责人: Rebecca J. Shaheen
• 金额: $ 4.29万
• 依托单位: OHIO STATE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-08-01 至 2026-07-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10751644
• 关键词: Acute; Affect; American; Anterior Descending Coronary Artery; Area; Arrhythmia; Automobile Driving; Binding Sites; Biology; Biomechanics; Cardiac; Cardiac Myocytes; Cause of Death; Cell Communication; Cell Death; Cell Nucleus; Cells; Cessation of life; Chronic; Chronic stress; Cicatrix; Communication; Complex; Cytoskeletal Proteins; Data; Deposition; Distant; Environment; Equilibrium; Event; Extracellular Matrix; Fibroblasts; Fibrosis; Functional disorder; Gene Expression; Generations; Genetic; Goals; Heart; Heart failure; Hypertrophy; Infarction; Inflammatory; Intercalated disc; Intervention; Knock-in Mouse; Left; Ligation; Link; Measures; Membrane; Molecular; Mus; Myocardial; Myocardial Infarction; Myocardial dysfunction; Myocardium; Myofibroblast; Nuclear; Outcome; Paracrine Communication; Pathologic; Pathway interactions; Patient-Focused Outcomes; Patients; Phase; Phenotype; Phosphorylation; Phosphorylation Site; Play; Prevention; Process; Proliferating; Protein Isoforms; Proteins; Regulation; Risk; Role; Rupture; Sentinel; Signal Transduction; Signaling Molecule; Spectrin; Stimulus; Stress; Stretching; Testing; Time; Tissues; Transcriptional Activation; Transducers; Vascular blood supply; Work; betaIV spectrin; calmodulin-dependent protein kinase II; chemokine; cytokine; disability; exosome; experimental study; gene function; genetic regulatory protein; healing; improved; insight; ischemic injury; migration; mouse model; novel; paracrine; preservation; recruit; repaired; response; response to injury; spatiotemporal; stressor; therapeutic target; transcription factor

Project Summary Myocardial infarction (MI) is a major cause of death and disability worldwide, affecting ~800,000 Americans annually. Optimal healing of the damaged tissue requires the delicate balance, both spatially and temporally, of inflammatory and reparative mechanisms to create the fibrotic scar. Cardiac fibroblasts (CFs) are the main contributor to fibrotic remodeling. Following ischemic injury, CFs transition into an activated phenotype that is characterized by increased proliferation, migration to the infarct region, and secretion of fibrotic proteins and paracrine signals. At the same time, dysregulation of the CF response to injury can promote pathological fibrosis, increased risk for arrhythmia, and cardiac dysfunction. While there has been many studies exploring the diverse signaling cascades and stressors that cause CF activation, how these stressors regulate the CF phenotype and paracrine signal generation, both spatially and temporally, remain elusive. Recent work identified stress-induced loss of the cytoskeletal protein, βIV-spectrin, to be an important step in CF activation and fibrosis3. Further, loss of βIV-spectrin was found to depend on Ca2+/ calmodulin-dependent protein kinase II (CaMKII). A broader role has been identified for βIV-spectrin/CaMKII in regulating CF gene expression through an interaction with signal transducer and activation of transcription 3 (STAT3)3,4, a signaling molecule and transcription factor that promotes profibrotic mechanisms. Specifically, CaMKII is activated and promotes loss of βIV-spectrin and redistribution of STAT3 to the nucleus that lead to changes in gene expression. Together, this leads to the hypothesis that the βIV-spectrin/STAT3 complex acts as a signaling node that is necessary for regulating cardiac fibroblast activation, recruitment, and scar formation post MI. To evaluate this hypothesis, Aim 1 will identify the role of the βIV-spectrin/STAT3 complex in CF activation and long-range communication. CFs will be subjected to both biomechanical stretch and neurohormonal stimuli, correlating to MI pathophysiology, to evaluate the effects on CF activation and exosome secretion. To understand how remote CFs migrate to the infarct area, long-range communication signals from spectrin-deficient CFs will be characterized and cultured with fresh CFs to see if they lead to activation. Additionally, this project will offer mechanistic insight into the spatiotemporal regulatory role of spectrin-based proteins in modulating exosome secretion following chronic stress. Lastly, Aim 2 will subject spectrin-preserved and spectrin-deficient mice to MI and evaluate the effects on scar formation and maturation. These studies will offer insight into how specific stress combinations tune the process of fibrotic remodeling following MI, and how these regulatory proteins can affect the overall outcome of MI patients.

项目概要 心肌梗塞 (MI) 是全球死亡和残疾的主要原因，影响约 80 万美国人 受损组织的最佳愈合需要空间和时间上的微妙平衡。 造成纤维化疤痕的炎症和修复机制是主要的。 缺血性损伤后，CF 转变为激活的表型。 其特征是增殖增加、向梗塞区域迁移以及纤维化蛋白的分泌和 同时，CF 对损伤的反应失调可促进病理性纤维化， 虽然有许多研究探索了不同的风险，但心律失常和心脏功能障碍的风险增加。 导致 CF 激活的信号级联和应激源，这些应激源如何调节 CF 表型以及 旁分泌信号的产生，无论是在空间上还是在时间上，仍然难以捉摸。 最近的研究发现，应激引起的细胞骨架蛋白 βIV-血影蛋白的丢失是 CF 的重要一步 此外，βIV-血影蛋白的丢失取决于 Ca2+/钙调蛋白依赖性蛋白。 βIV-血影蛋白/CaMKII 在调节 CF 基因表达中具有更广泛的作用。 通过与信号转导器相互作用并激活转录 3 (STAT3)3,4（一种信号分子） 和促进促纤维化机制的转录因子，具体而言，CaMKII 被激活并促进。 βIV-血影蛋白的丢失和 STAT3 重新分布到细胞核，共同导致基因表达的变化。 这导致了这样的假设：βIV-血影蛋白/STAT3 复合物充当信号传导节点，这是 调节心肌成纤维细胞活化、募集和心肌梗死后疤痕形成为了评估这一假设，Aim。 图 1 将确定 βIV-血影蛋白/STAT3 复合物在 CF 激活和长距离通讯中的作用。 将受到与 MI 病理生理学相关的生物力学拉伸和神经激素刺激， 评估对 CF 激活和外泌体分泌的影响，以了解远程 CF 如何迁移到外泌体。 在梗塞区域，来自血影蛋白缺陷 CF 的远程通信信号将被表征和培养 此外，该项目还将提供对新 CF 的机制洞察。 基于血影蛋白的蛋白质在调节慢性慢性病后外泌体分泌中的时空调节作用 最后，目标 2 将对保留血影蛋白和缺乏血影蛋白的小鼠进行 MI 并评估其影响。 这些研究将深入了解特定的压力组合如何调整疤痕。 心肌梗死后纤维化重塑的过程，以及这些调节蛋白如何影响总体结果 心梗患者。