The role of FGF-2 in HA-dependent FN production by HCs. Panel A shows the FN production by HCs after culture for 24 hours on BSA in the presence of supernatants obtained from either an equivalent culture (S) or from HCs cultured for 24 hours on HA (S^*). This is a representative of 3 experiments involving cells from 3 different patients. Original magnification, × 40. Panel B shows the relative amounts of FN produced by HCs cultured on BSA or HA or on BSA in the presence of recombinant FGF-2 (200 pg/mL) or of supernatants (S^*) from cells cultured on HA. Panel C shows the blocking of FN production by anti–FGF-2 antibody, but not by anti-TGFβ or IgG control antibodies, in cultures of HCs on HA. Panel D shows the effect of anti–FGF-2 or anti-TGFβ antibodies on FN production induced by supernatants of HCs cultured on HA (S^*). The amounts of FN produced in the presence of BSA alone or in the presence of supernatant (S^*) and IgG control antibody are shown for comparison. In panels B-D, the results represent the means (± SEM) of 3 experiments involving 3 different patients.