Preclinical Cardiac Electrophysiology Assessment by Dual Voltage and Calcium Optical Mapping of Human Organotypic Cardiac Slices

Sharon  A. George; Jaclyn  A. Brennan; Igor R. Efimov

doi:10.3791/60781

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Method Article

Preclinical Cardiac Electrophysiology Assessment by Dual Voltage and Calcium Optical Mapping of Human Organotypic Cardiac Slices

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DOI:

10.3791/60781

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June 16th, 2020

Sharon A. George^*¹ , Jaclyn A. Brennan^*¹ , Igor R. Efimov¹

¹Department of Biomedical Engineering, The George Washington University

^* These authors contributed equally

Summary

This protocol describes the procedure for sectioning and culturing human cardiac slices for preclinical drug testing and details the use of optical mapping for recording transmembrane voltage and intracellular calcium signals simultaneously from these slices.

Abstract

Human cardiac slice preparations have recently been developed as a platform for human physiology studies and therapy testing to bridge the gap between animal and clinical trials. Numerous animal and cell models have been used to examine the effects of drugs, yet these responses often differ in humans. Human cardiac slices offer an advantage for drug testing in that they are directly derived from viable human hearts. In addition to having preserved multicellular structures, cell-cell coupling, and extracellular matrix environments, human cardiac tissue slices can be used to directly test the effect of innumerable drugs on adult human cardiac physiology. What distinguishes this model from other heart preparations, such as whole hearts or wedges, is that slices can be subjected to longer-term culture. As such, cardiac slices allow for studying the acute as well as chronic effects of drugs. Furthermore, the ability to collect several hundred to a thousand slices from a single heart makes this a high-throughput model to test several drugs at varying concentrations and combinations with other drugs at the same time. Slices can be prepared from any given region of the heart. In this protocol, we describe the preparation of left ventricular slices by isolating tissue cubes from the left ventricular free wall and sectioning them into slices using a high precision vibrating microtome. These slices can then either be subjected to acute experiments to measure baseline cardiac electrophysiological function or cultured for chronic drug studies. This protocol also describes dual optical mapping of cardiac slices for simultaneous recordings of transmembrane potentials and intracellular calcium dynamics to determine the effects of the drugs being investigated.

Introduction

Animal models have been a valuable tool used for understanding the underlying mechanisms of human physiology and pathophysiology, as well as a platform for preliminary testing of therapies to treat various diseases¹. Great strides have been taken in the field of biomedical research based on these animal studies². However, significant interspecies differences exist between human and animal physiologies, including mice, rats, guinea pigs, rabbits, sheep, pigs, and dogs³^,⁴. As a result, there have been numerous drug, gene, and cell therapies that showed promise duri....