Recellularized atria using light controllable hIPSC-derived atrial cells for arrhytmia modeling

Matteo Ghiringhelli ¹ Yehuda Wexler ¹ Amit Gruber ¹ Oded Edri ¹ Michal Landesberg ¹ Shany Glatstein ¹ Yousef Abboud ¹ Assad Shiti ¹ Nimer Ballan ¹ Daniel Shiff ¹ Irit Huber ¹ Gil Arbel ¹ Lior Gepstein ^1,2

¹Physiology, Sohnis Research laboratory for Cardiac Electrophysiology and Regenerative Medicine, the Rappaport Faculty of Medicine and Research Institute, Technion-Israel Institute of Technology, Israel
²Cardiology, Rambam Health Care Campus, Israel

Introduction: Construction of three-dimensional atria using decellularized extracellular matrix could allow the creation of ‘‘organ-like’’ structures for disease modeling, drug testing and regenerative medicine applications. To complete this task we aimed to combiQ ne human induced pluripotent stem cell (hiPSC) technology, decellularization/recellularization processes, and optogenetics utilizing light-sensitive ion channels to generate light-controllable atrial tissue engineered patches.
Material and method: Atria of adult rats and pig left atrial appendage appendage were decellularized using 1% SDS, 3% triton-X. The decellularized scaffolds were then recellularized with hiPSC- derived cardiomyocytes (2-8 x107 atrial cells). Adenoviral transduction was used to express the light-sensitive cationic channel ChR2 in the tissue engineered constructs.
Results and discussion: We observed the development of spontaneous contraction of the atrial tissues and the response to chamber-specific pharmacology confirmed the atrial specific identity of the patches. Histological examination, X-ray microtomography (micro-CT) and magnetic resonance imaging (MRI) scanning confirmed the preservation of the macro/micro-atrial/ventricular anatomical features in the generated chamber-specific recellularized patches. Optical mapping, using an EM-CCD camera, was used to characterize the conduction and repolarization properties of the generated tissues. The engineered patches could be paced and their electrical activity controlled by either electrical or optogenetic stimulation. Finally, arrhythmogenic reentrant arrhythmias could be induced in the tissue models and terminated by using optogenetic stimulation ("optogenetic-defibrillation").
Conclusions: Three-dimensional light-sensitive chamber-specific engineered heart patches could be generated that could be controlled and manipulated through electrical and light pacing. These tissues could be used for several pathophysiological, drug testing, disease modeling and regenerative medicine applications.