Satellite Glial Cell Activation and Sympathetic Imbalance in Cardiomyopathy and Arrhythmias

项目摘要/摘要 心脏损伤使患者容易发生心力衰竭(HF)和室性心动过速/纤颤(VT/VF)。 心脏损伤后心衰和室速/室颤的发生与交感神经重构密切相关。虽然 几种针对心脏交感神经过度的药物降低了心脏损伤后的死亡率，意义重大 这些药物的缺点包括非靶向效应、有限的疗效和专注于下游 神经重塑的后果，如过量的儿茶酚胺释放，而不是阻止它上游。 在这项建议中，我们建立在来自人类、猪和小鼠模型的强大初步数据的基础上 卫星胶质细胞(SGC)的激活是慢性心脏损伤的一个主要特征。激活的神经胶质细胞释放 炎性细胞因子、三磷酸腺苷和其他调节神经功能的因素。化学发生上调的研究进展 神经胶质钙信号(如在激活的神经胶质细胞中观察到的)增加心脏交感神经元的兴奋性， 突触功效和紧张性放电。基于这些新的发现，这项提案的目标是测试 假设卫星神经胶质细胞激活和增强的神经胶质细胞信号是心脏疾病的主要驱动因素 交感神经功能障碍、心力衰竭和心脏损伤后室速/室颤。 我们将使用来自三个具体领域的多学科研究团队的新工具来测试我们的假设 目的是在两种小鼠心脏损伤模型(缺血-再灌注和扩张型心肌病)中进行研究。我们将测试 心脏损伤后，星状神经节内卫星神经胶质细胞的激活是否加剧了神经元和 心脏重构(结构和功能)，以促进左心功能不全和室速/室颤(目标1)。我们会 探讨心脏损伤后激活星状神经节SGCs的机制(目标2)。 最后，我们将确定靶向神经胶质细胞Gq-GPCRCa~(2+)信号或Cx43介导的神经胶质细胞/胶质细胞- 神经胶质通讯减轻心脏损伤后的不良重构和心律失常的发生(目标3)。这个 这一提议的结果将1)表明卫星神经胶质细胞激活是否以及如何有助于交感神经 心脏损伤后的失衡；以及2)确定靶向卫星神经胶质细胞激活是否提供 慢性心脏损伤的治疗潜力。

PROJECT SUMMARY/ABSTRACT Cardiac injury predisposes patients to heart failure (HF), and ventricular tachycardia/fibrillation (VT/VF). Development of HF and VT/VF after cardiac injury is tightly linked to sympathetic neural remodeling. Although several medications targeting cardiac sympathetic excess reduce mortality following cardiac injury, significant shortcomings of these drugs include off-target effects, limited efficacy, and focus on downstream consequences of neural remodeling such as excess catecholamine release, rather than preventing it upstream. In this proposal, we build on strong preliminary data from humans, porcine, and murine models demonstrating that satellite glial cell (SGC) activation is a central feature of chronic cardiac injury. Activated glia release inflammatory cytokines, ATP, and other factors that modulate neuronal function. Chemogenetic upregulation of glial calcium signaling (as observed in activated glia) increase cardiac sympathetic neuronal excitability, synaptic efficacy, and tonic firing. Based on these novel findings, the goal of this proposal is to test the hypothesis that satellite glial activation and enhanced glial-neuronal signaling is a primary driver of cardiac sympathetic neuronal dysfunction, heart failure and VT/VF after cardiac injury. We will test our hypotheses using novel tools from a multidisciplinary team of investigators in 3 specific aims in two murine models of cardiac injury (ischemia-reperfusion and dilated cardiomyopathy). We will test whether following cardiac injury, satellite glial cell activation within stellate ganglia exacerbates neuronal and cardiac remodeling (structural and functional) to promote LV dysfunction and VT/VF (Aim 1). We will investigate the mechanisms by which cardiac injury activates SGCs in stellate ganglia after injury (Aim 2). Finally, we will determine whether targeting glial Gq-GPCR Ca2+ signaling or Cx43-mediated glia-neuron/glial- glial communication mitigates adverse remodeling and arrhythmogenesis following cardiac injury (Aim 3). The results of this proposal will 1) indicate whether and how satellite glial cell activation contributes to sympathetic imbalance after cardiac injury; and 2) determine whether targeting satellite glial cell activation offers therapeutic potential in chronic cardiac injury.