Mechanical preconditioning enables electrophysiological coupling of skeletal myoblast cells to myocardium

Klaus Neef, Sureshkumar Perumal Srinivasan, Philipp Treskes, Roland Adelmann, Markus Khalil, Christof Stamm, Thorsten Wittwer, Thorsten Wahlers, Yeong-Hoon Choi

Research output: Contribution to conferencePosterpeer-review

Abstract

Introduction: Skeletal myoblasts (SMB) are being discussed controversially as a substrate for cardiac regenerative cell therapy. A major issue is that native SMB fail to couple electrically and functionally to the host myocardium. We present a novel approach using SM based engineered tissue constructs (ETC) resolving the issue of native conduction block between SMB and cardiomyocytes.

Methods: SMB from skeletal muscle tissue of neonatal mice from cell culture expansion were used to generate ETC, either with or without application of directed mechanical strain. After submission to cell culture conditions enabling myotube formation, ETC were co-cultured for three days with viable slices of embryonic hearts. Electrophysiological measurements were performed by sharp electrodes to assess the electrical coupling between the ETC and the myocardium. Furthermore, pharmacological studies were performed to characterize the established underlying electrophysiological connection.

Results: Our protocol for the isolation of SM from skeletal muscle tissue resulted in high yields of homogeneous cell populations (97.1±0.1%) desmin positive cells. Mechanical strain was exerted on myotubes within ETC during polymerization of the matrix, generating preconditioned ETC (P-ETC). Electrophysiological measurements revealed electrical coupling between P-ETC and heart slices, but no coupling between ETC without directed mechanical strain and heart slices. Stimulation of cells within P-ETC and recording of resulting action potentials in cells within the heart slice showed delayed response, as compared to stimulation of cells within the heart tissue (P-ETC vs. heart: 16.6±5.2ms vs. 6.25±2.9ms, p<0.001). Furthermore, increasing frequency of stimulation up to 6Hz from P-ETC resulted in coordinated response in the heart tissue, while stimulation up to 10Hz was possible from the heart tissue. Sensitivity for reversible cardiac specific gap junction block was also higher for P-ETC stimulation (0.22±0.6 mM heptanol) than for stimulation within host tissue.

Conclusion: In contrast to the limited electrical coupling ability of native SMB, the presented approach allows the generation of SMB based ETC transplantable cellular grafts that couple electro-mechanically to myocardium. This represents a milestone for cardiac cell therapy and abolishes the paradigm against the application of SMB for the regeneration of the heart.
Original languageEnglish
Publication statusPublished - 12 Feb 2012
Event41st Annual Meeting of the German Society for Cardiovascular and Thoracic Surgery, - Freiburg, Germany
Duration: 12 Feb 201215 Feb 2012

Conference

Conference41st Annual Meeting of the German Society for Cardiovascular and Thoracic Surgery,
CountryGermany
CityFreiburg
Period12/02/1215/02/12

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