The Use of Human Cardiac Organoids to Model COVID-19 Cytokine Storm Induced Cardiac Injury

摘要：截至2021年8月4日，新冠肺炎在美国已感染35,286,935人，死亡率为 1.73%。新冠肺炎引起的一个常见并发症是心脏受损所表现的急性心脏损伤。 功能。这些损伤与新冠肺炎患者预后不良和死亡率增加有关。 虽然急性心脏损伤是新冠肺炎死亡的主要原因，但其根本原因并未 已澄清。在导致新冠肺炎感染的多种因素(例如，直接病毒感染)中 心肌病，最近的临床数据表明，细胞因子风暴是一个主要因素。新冠肺炎感染 启动免疫系统的超生理激活，从而导致炎症的释放 细胞因子(如IL-1E、IL-2、IL-6、IL-10、TNFD、G-CSF和MIP1D)进入循环，导致器官毒性，如 作为血管不稳定和不良心脏事件。尽管新冠肺炎细胞因子风暴在急性胰腺炎中发挥了关键作用 心脏损伤，目前缺乏动物和体外模型，限制了对其机制的了解和 药物开发。此外，虽然最近的临床数据表明，患有急性心脏病的新冠肺炎幸存者 损伤可能会经历长期的心脏异常，结果研究可能需要数年时间才能完成，因为 这种冠状病毒的新颖性。这突显了一种尚未得到满足的需求，即开发一种能够预测长期增长的有效模型。 新冠肺炎恢复期患者的远期心脏结局为临床监测和指导 治疗性干预。我们的有机化合物为解决这一问题提供了一个强大的平台。有机化合物是 由hPSC来源的心肌细胞、人心脏成纤维细胞、人内皮细胞和血管 支持细胞。本方案的目的是建立一种新冠肺炎细胞因子风暴诱导的体外模型 利用细胞(如成纤维细胞、内皮细胞)的固有炎症特性造成的急性心脏损伤 在有机体中，因为这些细胞已经被证明在 刺激。IL-1E是单核细胞在病毒感染后最先释放的细胞因子之一，已知 诱导IL-6的产生，在细胞因子风暴中扮演中心角色。这项提议的中心假设是 IL-1E可诱导机体产生细胞因子风暴，重演新冠肺炎所致的急性心脏损伤。 这项提议是创新的，因为我们将利用病毒感染诱导的上游细胞因子刺激(IL-1E) 启动内源性炎症反应，模拟有机体内的细胞因子风暴。因此，我们 将追求两个目标：1)使用IL-1E处理的心脏器官来模拟新冠肺炎细胞因子风暴诱导的 心脏损伤，确定潜在的机制，并测试免疫调节药物的效果，以及2) 使用人体心脏器官评估新冠肺炎细胞因子风暴的远期心脏并发症。这个 拟议的研究将建立一个体外模型系统，以阐明COVID的基本机制-- 19细胞因子风暴引起的心脏损伤，证明了它在药物测试中的有效性，并提供了对 新冠肺炎感染对心脏的远期影响，指导临床监测和治疗干预。

Abstract: As of August 4, 2021, COVID-19 has infected 35,286,935 people in the US with a mortality rate of 1.73%. One common COVID-19 induced complication is acute cardiac injury manifested by impaired cardiac function. These injuries have been associated with poor prognosis and increased mortality for COVID-19 patients. While acute cardiac injury is a major contributor to COVID-19 mortality, the underlying causes have not been elucidated. Among multiple factors (e.g., direct viral infection) that can contribute to COVID-19 induced cardiomyopathies, recent clinical data indicates that cytokine storm is a major contributor. COVID-19 infection initiates supraphysiological activation of the immune system, which leads to the release of inflammatory cytokines (e.g., IL-1E, IL-2, IL-6, IL-10, TNFD, G-CSF and MIP1D) into circulation, resulting in organ toxicity such as vascular instability and adverse cardiac events. Despite the critical roles of COVID-19 cytokine storm in acute cardiac injury, the current lack of animal and in vitro models has limited the mechanistic understanding and drug development. Further, while recent clinical data suggests that COVID-19 survivors with acute cardiac injuries can experience long-term cardiac abnormalities, outcome studies may take years to complete due to the novelty of this coronavirus. This highlights an unmet need to develop an effective model that can predict long- term cardiac outcomes of convalescent COVID-19 patients to provide guidance for clinical monitoring and therapeutic interventions. Our organoids provide a powerful platform to address this. The organoids are composed of hiPSC derived cardiomyocytes, human cardiac fibroblasts, human endothelial cells, and vascular supporting cells. The goal of this proposal is to develop an in vitro model for COVID-19 cytokine storm induced acute cardiac injuries by leveraging the innate inflammatory properties of cells (e.g., fibroblasts, endothelial cells) in the organoids, as these cells have been shown to produce various proinflammatory cytokines under stimulation. IL-1E is one of the first cytokines released from monocytes in response to viral infection and is known to induce IL-6 production, the central player in cytokine storm. The central hypothesis of this proposal is that IL-1E will induce cytokine storm in the organoids and recapitulate the COVID-19 induced acute cardiac injuries. This proposal is innovative in that we will harness a viral infection induced upstream cytokine stimulus (IL-1E) to initiate an endogenous inflammatory response to simulate cytokine storm in the organoids. Accordingly, we will pursue the two aims: 1) Use IL-1E treated cardiac organoids to model COVID-19 cytokine storm induced cardiac injuries, determine the underlying mechanisms, and test the effects of immunomodulatory drugs, and 2) Use human cardiac organoids to assess the long-term cardiac complications of COVID-19 cytokine storm. The proposed research will establish an in vitro model system to elucidate the fundamental mechanisms of COVID- 19 cytokine storm induced cardiac injuries, demonstrate its validity for drug testing, and provide insights on the long-term cardiac effects of COVID-19 infection to guide clinical monitoring and therapeutic interventions.