Cardiac Physiology and Imaging Core

Abstract The Cardiac Physiology and Imaging Core (Core C) will provide service to all 4 projects with the goals of generating functional and structural analyses of human Embryonic Stem Cell-derived cardiomyocytes (hESC- CMs; Aim 1) and the adult mouse heart (Aim 2). Specifically, assays utilized in Aim 1 will provide high quality unbiased assessment of hESC-CM structure and function. Core C’s services enhance the efficiency of the Projects by providing consistent expertise in the functional and structural evaluation of hESC-CMs using a variety of complementary techniques. These include confocal fluorescence microscopy for structural evaluation as well as cytosolic [Ca2+] and membrane voltage imaging, an electrode array system for multicellular electrophysiological and contractile assessment, Transmission Electron Microscopy (TEM) for ultrastructural analyses, the patch-clamp technique for single hESC-CM electrophysiological measurements, and in situ hybridization (RNAscope) for evaluation of spatial gene expression patterns. Project 1 benefits from Core C in the analyses of gene expression at the single cell level. Projects 2 and 3 benefit from Core C in the quantitative assessment of electrical and contractile properties of hESC-CMs. All Projects benefit from the quantitative analysis of sarcomeric organization, polarity and shape of hESC-CMs. Techniques to be used in Aim 2 will provide high quality unbiased functional and structural assessment of the adult mouse heart. Core C’s services include ultra-high frequency ultrasound of mice, surface ECG in anesthetized mice, telemetric ECG monitoring of conscious mice, optical voltage / calcium mapping of isolated mouse hearts, and quantitation of cardiomyocyte S-phase activity using a custom-built imaging system. The Core will generate high-resolution ultrasound images in Projects 3 in order to provide quantitative data of structure, function, and flow relative to genetic alterations in cardiac development. ECG and voltage / calcium mapping will provide quantitation of cardiac electrical function in Projects 2 and 3. Quantitation of cardiomyocyte S-phase activity will aid in assessing effects of proposed genetic alterations on cardiomyocyte proliferation in all Projects.