Fig. 8.

Plating DCDMLs on FN renders FGF-induced fiber cell differentiation insensitive to noggin, and sensitivity is restored when TGFβ signaling is inhibited. DCDMLs were plated on laminin or pdFN on day 0 and cultured from day 1 to day 7 in M199/BOTS with no additions (0), 10 ng/ml FGF2 (A), or 10 ng/ml BMP4 (B), in the presence or absence of the BMP2/4/7 blocker noggin or SB431542 as indicated. Cells were assayed for synthesis of fiber cell differentiation markers as in Fig. 4. (C) The extent to which the treatments in A reduced fiber marker expression was calculated as fold­-change versus the values obtained from cells plated on laminin and cultured with FGF in the same experiment. *P≤0.001; all other data sets, P>0.08. Not shown: When plated on either laminin or pdFN, noggin blocked fiber marker expression in response to BMP4 by ≥95% (n=3).