CAREER: Understanding Atrial Arrhythmia Mechanisms with Patient-derived Engineered Tissues

心房颤动（AFib）是心脏中最常见的电传导障碍，但AFib的潜在原因尚不清楚，特别是当单一基因不负责时，如沃尔夫-帕金森-怀特（WPW）综合征，一种心脏上下心室之间额外的电通路导致心跳加快的疾病。本CAREER项目的目标是开发患者特异性细胞工程组织模型和计算机模型，以研究心律失常触发因素的作用，包括生物力学和情绪压力。使用从WPW患者和健康家庭成员获得的干细胞工程化的心脏组织的电和收缩特性将在组织拉伸和/或暴露于生理刺激物时进行测量。从实验和计算机模型中获得的知识将促进治疗发展和改善病人护理，从而促进国民健康。通过支持外展和教育，该项目推进了NSF的使命，即通过学校科学项目和艺术来解决普罗维登斯社区文化变革的需求，从而增加STEM的多样性和包容性，这些项目旨在吸引和授权代表性不足的学生、家长、教师和公众。活动包括推出一个包含教师培训和实践课程的“工程之心”三年级模块，为家长和公众举办科学艺术展，以提高STEM教育的参与度，并鼓励文化变革，促进STEM的公平。研究人员的研究重点是通过开发新的技术和平台来改善人类心脏健康，以再生肌肉，预测毒性和了解疾病。与此重点一致，本CAREER项目的目标是了解离子电流和组织几何形状如何引发和维持WPW中的心律失常，如快速心率和心房纤颤。由于房性心律失常的机制往往是多因素的，由心房组织的结构和电生理重构驱动，因此迫切需要开发能够分离心律失常机制的实验平台，以便解剖房性心律失常并促进治疗开发。为了满足这一需求，将开发新的人类体外和计算模型，以使个体扰动及其组合在兴奋和收缩中引起心律失常的表型。生理功能将在含有患者来源的人诱导多能干细胞（hiPSC）来源的心房心肌细胞的3D工程组织中进行评估，以解决机械拉伸，高血压和情绪压力相关的假设（β-肾上腺素能通路或“战斗或逃跑”反应的激活）将增加自动性，频率依赖性收缩和传导不规则性，以揭示再入途径。研究目标是：(1)获得新的患者和控制hiPSC系，并评估分化的心房心肌细胞的心房特异性和WPW表型，(2)使用3D工程组织评估心房特异性离子通道调节剂的兴奋和收缩反应，并使用我们的计算动作电位模型来了解hiPSC-心房心肌细胞离子电流。(3)利用三维实验和计算大组织来评估拉伸和β-肾上腺素能刺激如何调节兴奋和收缩的心律失常表型。该研究项目将提高研究能力，通过量身定制的工程组织来研究和理解各种心律失常机制，以改善数百万心房颤动患者的诊断、分层、健康和生活质量。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

Atrial fibrillation (AFib) is the most common electrical conduction disorder in the heart, yet the underlying cause of AFib is poorly understood, particularly when a single gene is not responsible such as in Wolff-Parkinson-White (WPW) syndrome, a disorder in which an extra electrical pathway between the heart's upper and lower chambers causes a rapid heartbeat. The goal of this CAREER project is to develop patient-specific cellular engineered tissue models and computer models to study the roles of arrhythmic triggers, including biomechanical and emotional stress. The electrical and contractile properties of cardiac tissues engineered using stem cells obtained from WPW patients and healthy family members will be measured as the tissues are stretched and/or exposed to physiological stimulants. The knowledge gained from experiments and computer models will facilitate therapeutic development and improve patient care, thus advancing national health. Through supporting outreach and education, the project advances NSF’s mission to increase diversity and inclusion in STEM by addressing a need for cultural change in the Providence community through school science programs and art designed to engage and empower underrepresented students, parents, teachers, and the public. Activities include launching an “Engineering the Heart” 3rd grade module with teacher training and hands-on curricula and developing a science art exhibit for parents and the public to increase engagement in STEM education and encourage cultural change for equity in STEM.The investigators’s research focus is on improving human heart health through developing novel technologies and platforms for regenerating muscle, predicting toxicity, and understanding disease. Consistent with this focus, the goal of this CAREER project is to understand how ion currents and tissue geometry initiate and sustain arrhythmias in WPW like fast heart rate and AFib. As the mechanisms underlying atrial arrhythmia are often multi-factorial, driven by structural and electrophysiological remodeling in atrial tissue, there is a significant need for developing experimental platforms that can isolate arrhythmia mechanisms in order to dissect atrial arrhythmias and enable therapeutic development. To address this need, novel human in vitro and computational models will be developed to enable individual perturbations and their combinations to elicit arrhythmic phenotypes in excitation and contraction. Physiological function will be assessed in 3D engineered tissues containing patient-derived human induced pluripotent stem cell (hiPSC)-derived atrial cardiomyocytes to address the hypothesis that mechanical stretch, a correlate of high blood pressure, and emotional stress (activation of β-adrenergic pathways or the “fight-or-flight” response) will increase automaticity, frequency-dependent contractions, and conduction irregularities to reveal reentry pathways. The research objectives are to (1) derive new patient and control hiPSC lines and evaluate differentiated atrial cardiomyocytes for atrial specificity and WPW phenotype, (2) use 3D engineered tissues to evaluate excitation and contraction responses to atrial-specific ion channel modulators and use our computational action potential model to understand hiPSC-atrial cardiomyocyte ion currents in WPW, and (3) use 3D experimental and computational macrotissues to assess how stretch and β-adrenergic stimulation modulate arrhythmic phenotypes of excitation and contraction. This research project will advance the capabilities in research to study and understand diverse arrhythmia mechanisms with tailored engineered tissue to improve the diagnosis, stratification, health, and quality of life for millions of patients with AFib.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.