In vitro reestablishment of cell‐cell contacts in adult rat cardiomyocytes. Functional role of transmembrane components in the formation of new intercalated disk‐like cell contacts

Primary adult rat cardiomyocytes (ARC) in culture are shown to be a model system for cardiac cell hypertrophy in vitro . ARC undergo a process of morphological transformation and grow only by increase in cell size, however, without loss of the cardiac phenotype. The isolated cells spread and establish new cell‐cell contacts, eventually forming a two‐dimensional heart tissue‐like synchronously beating cell sheet. The reformation of specific cell contacts (intercalated disks) is shown also between ventricular and atrial cardiomyocytes by using antibodies against the gap junction protein connexin‐43 and after microinjection into ARC of N‐cadherin cDNA fused to reporter green fluorescent protein (GFP) cDNA. The expressed fusion protein allowed the study of live cell cultures and of the dynamics of the adherens junction protein N‐cadherin during the formation of new cell‐cell contacts. The possible use of the formed ARC cell‐sheet cells under microgravity conditions as a test system for the reformation of the cytoskeleton of heart muscle cells is proposed.—Eppenberger, H. M., Zuppinger, C. In vitro reestablishment of cell—cell contacts in adult rat cardiomyocytes. Functional role of transmembrane components in the formation of new intercalated disklike cell contacts. FASEB J. 13 (Suppl.), S83–S90 (1999)