N-Cadherin: structure, function and importance in the formation of new intercalated disc-like cell contacts in cardiomyocytes.

N-Cadherin belongs to a superfamily of calcium-dependent transmembrane adhesion proteins. It mediates adhesion in the intercalated discs at the termini of cardiomyocytes thereby serving as anchor for myofibrils at cell-cell contacts. A large body of data on the molecular structure and function of N-cadherin exists, however, little is known concerning spatial and temporal interactions between the different junctional structures during formation of the intercalated disc and its maturation in postnatal development. The progression of compensated left ventricular hypertrophy to congestive left heart failure is accompanied by intercalated disc remodeling and has been demonstrated in animal models and in patients. The long-term culture of adult rat cardiomyocytes allows to investigate the development of de novo intercalated disc-like structures. In order to analyze the dynamics of the cytoskeletal redifferentiation in living cells, we used the expression of chimeric proteins tagged with the green fluorescent protein reporter. This technique is becoming a routine method in basic research and complements video time-lapse and confocal microscopy. Cultured cardiomyocytes have been used for a variety of studies in cell biology and pharmacology. Their ability to form an electrically coupled beating tissue-like network in culture possibly allows reimplantation of such cells into injured myocardium, where they eventually will form new contacts with the healthy muscle tissue. Several groups have already shown that cardiomyocytes can be grafted successfully into sites of myocardial infarcts or cryoinjuries. Autologous adult cardiomyocyte implantation, might indeed contribute to cardiac repair after infarction, thanks to advances in tissue engineering.