Cardiac fibroblasts are the principle cell type responsible for extracellular matrix (ECM) production. They are the predominant cell type of the heart by number but not by volume. Fibroblasts are responsible for the deposition of collagen.
DDR2 expression was shown to be specific for cardiac fibroblasts. When using DDR2 as a marker, fibroblasts were observed to be interconnected by gap junctions and formed a 3-D network intimately associated with myocytes and the connective tissue network of the heart.
Neonatal cardiac fibroblasts were obtained by collagenase digestion of 3- to 4-day-old neonatal rat hearts. Fibroblasts were separated from myocytes by selective cellular attachment. Fibroblasts were cultured in Dulbecco’s modified Eagle medium (DMEM) supplemented with newborn bovine serum (10%), fetal bovine serum (5%), penicillin G (100 U/ml), streptomycin (100 g/ml), amphotericin B (1 g/ml), and gentamicin (10 g/ml).