Physiologic biomechanics enhance reproducible contractile development in a stem cell derived cardiac muscle platform

Yao-Chang Tsan,Samuel J Depalma,Kenneth K Y Ho,Allen P Liu,Lori L Isom,David Nordsletten,Nadab Wubshet,Isabella Panse,Yu-Wei Wu,Thomas S O’Leary,Michael J Previs,Daniel L Matera,Kathryn Ufford,Adam S Helms,Adela Capilnasiu,Sabrina Friedline,Brendon M Baker,Yan-Ting Zhao,Brynn Elder

doi:10.1038/s41467-021-26496-1

Abstract

Human pluripotent stem cell-derived cardiomyocytes (hPSC-CMs) allow investigations in a human cardiac model system, but disorganized mechanics and immaturity of hPSC-CMs on standard two-dimensional surfaces have been hurdles. Here, we developed a platform of micron-scale cardiac muscle bundles to control biomechanics in arrays of thousands of purified, independently contracting cardiac muscle strips on two-dimensional elastomer substrates with far greater throughput than single cell methods. By defining geometry and workload in this reductionist platform, we show that myofibrillar alignment and auxotonic contractions at physiologic workload drive maturation of contractile function, calcium handling, and electrophysiology. Using transcriptomics, reporter hPSC-CMs, and quantitative immunofluorescence, these cardiac muscle bundles can be used to parse orthogonal cues in early development, including contractile force, calcium load, and metabolic signals. Additionally, the resultant organized biomechanics facilitates automated extraction of contractile kinetics from brightfield microscopy imaging, increasing the accessibility, reproducibility, and throughput of pharmacologic testing and cardiomyopathy disease modeling.

Highlights

Human pluripotent stem cell-derived cardiomyocytes allow investigations in a human cardiac model system, but disorganized mechanics and immaturity of hPSC-CMs on standard two-dimensional surfaces have been hurdles
We demonstrate that the reproducible contractile microenvironment of 2D cardiac muscle bundle (2DMB) allows them to be used as a test bed for investigation of developmental cues that intersect with contractile function, and as a platform for precise dissection of contractile kinetics in cardiomyopathy disease models in a simplified 2D system
This finding motivated the development of a platform to generate geometrically defined multicellular cardiomyocyte constructs that harness the benefits of reproducible myofibrillar alignment and uniaxial contractility via micropatterning[9,10,14], while enabling hPSC-CM connectivity

Summary

Introduction

Human pluripotent stem cell-derived cardiomyocytes (hPSC-CMs) allow investigations in a human cardiac model system, but disorganized mechanics and immaturity of hPSC-CMs on standard two-dimensional surfaces have been hurdles. In our micron-scale 2D cardiac muscle bundle (2DMB) approach, we use micropatterning of elastic polydimethylsiloxane (PDMS) to anchor thin, purified cardiac muscle strips in 2D arrays with improved attachment yield than has been possible with single cells In these arrays, individual cardiac muscle bundles have a controlled geometry and contract independently against a defined workload. Individual cardiac muscle bundles have a controlled geometry and contract independently against a defined workload Using this highly organized biomechanical environment, we show that myofibrillar alignment and physiologic (auxotonic) contractions in an optimized media environment drive marked development of contractile function, calcium handling, and electrophysiology. We demonstrate that the reproducible contractile microenvironment of 2DMBs allows them to be used as a test bed for investigation of developmental cues that intersect with contractile function, and as a platform for precise dissection of contractile kinetics in cardiomyopathy disease models in a simplified 2D system

Objectives

Methods

Results

Conclusion