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.

项目摘要 心肌梗塞（MI）是全球死亡和残疾的主要原因，影响了约80万美国人 损坏的组织的最佳愈合需要空间和临时的微妙平衡 炎症和修复机制可产生纤维化疤痕。心脏成纤维细胞（CFS）是主要的 纤维化重塑的贡献者。缺血性损伤后，CFS转变为激活的表型 其特征是增殖增加，迁移到梗塞区域以及纤维化蛋白的分泌和 旁分泌信号。同时，CF对损伤反应的失调可以促进病理纤维化， 心律不齐和心脏功能障碍的风险增加。虽然有许多研究探索潜水员 信号传导级联和引起CF激活的压力源，这些压力源如何调节CF表型和 旁分泌信号的产生，无论是空间还是临时的，都难以捉摸。 最近的工作确定了应力诱导的细胞骨架蛋白β-spectrin的丧失是CF的重要一步 激活和纤维化3。此外，发现β-spectrin的丧失取决于Ca2+/钙调蛋白依赖性蛋白 激酶II（CAMKII）。在调节CF基因表达中，已经确定了β-spectrin/camkII的更广泛的作用 通过与信号换能器的相互作用和转录3的激活（STAT3）3,4，一个信号分子 和促进纤维化机制的转录因子。具体而言，Camkii被激活并促进 β-spectrin的丢失和STAT3重新分布到导致基因表达变化的细胞核。一起， 这导致了以下假设：β-spectrin/stat3复合物充当信号节点 调节心脏成纤维细胞激活，募集和疤痕形成MI。为了评估这一假设，目标 1将确定βIV-谱蛋白/STAT3复合物在CF激活和远程通信中的作用。 CFS 将遭受与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。了解远程CFS如何迁移到 梗塞区域，来自Spectrin缺陷CFS的远程通信信号将被表征和培养 使用新鲜的CF来查看它们是否导致激活。此外，该项目将提供有关机械的洞察力 基于光谱的蛋白在调节外泌体分泌过程中的时空调节作用 压力。最后，AIM 2将对光谱保存和光谱缺陷的小鼠进行MI并评估效果 关于疤痕形成和成熟。这些研究将提供有关特定压力组合如何调整的见解 MI之后的纤维化重塑过程，以及这些调节蛋白如何影响 MI患者。