FIBRONECTIN EXPRESSION DURING PHYSIOLOGICAL AND PATHOLOGICAL CARDIAC GROWTH

Fibronectin (FN) is a dimeric glycoprotein found in the extracellular matrix of most tissues that serves as a bridge between cells and the i nterstitial collagen meshwork and influences diverse processes includi ng cell growth, adhesion, migration, and wound repair. Multiple FN for ms arise by the alternative splicing of a primary transcript originati ng from a single gene, The spatial and temporal alterations in FN expr ession in the myocardium has been studied in models of cardiac growth in vivo such as fetal development, and hypertrophy secondary to pressu re overload, This review focuses on the differential expression of FN isoforms that are observed in different models of cardiac growth. Usin g a combination of qualitative and quantitative analyses it is shown t hat in the rat myocardium: (1) the FN phenotype is developmentally reg ulated, (2) the re-expression of the fetal FN isoforms is observed in different models of cardiac hypertrophy secondary to a sudden or progr essive hypertension and (3) the changes in cardiac FN expression affec t mostly the coronary artery smooth muscle cells.