INFLUENCE OF FETAL CALF SERUM AND FGF ON HUMAN CORNEAL KERATOCYTE CULTURE

Background To investigate the influence of fetal calf serum (FCS) and fibroblast growth factor (FGF) on human keratocyte growth in vitro and cell differentiation, and to describe cultured human keratocyte ultra -structure. Methods Human keratocytes were cultured in TC 199/Ham F12 media, supplemented or not with 10% FCS, aFGF, and bFGF. Keratocyte gr owth was studied. Cultured keratocytes were analyzed by means of immun ochemistry and transmission electron microscopy. Results Without fetal calf serum, cell population doubling occurred after 7 days of culture and no alpha smooth muscle-actin cell expression was observed. With s erum, cell population increased by 1 log after 7 days of culture and a ll of the cells were alpha SM-actin +. bFGF or aFGF-addition to the se rum-containing medium resulted in a dramatic decrease in this alpha SM -actin expression. Nuclei were found to be oval and regular in cross-s ections, and round and indented in frontal sections. Numerous cytoplas mic organelles were observed, as were cell expansions, gap junctions, omega-shaped structures, and fenestrations. Cultured keratocytes synth esized collagen fibers and filaments. Conclusion Fetal calf serum allo ws human keratocytes to grow with a myofibroblast cell phenotype, wher eas addition of FGF results in a fibroblast cell phenotype. Ultrastruc ture of cultured keratocyte is similar to that observed in situ.