Figure 3
ECM regulation by collagen synthesis, protease activity, and TIMP inhibition. (A) Collagen synthesis was assessed by measurement of 3H-proline incorporation. TGFβ1 increased 3H-proline incorporation. This effect was abolished by addition of LMW-FGF-2. (B) ECM degradation was assessed by in situ zymography using embedded DQ™ Gelatin-FITC to measure matrix proteolysis. Total protease activity was quantified as total fluorescent signal per image volume. TGFβ1 increased total protease activity while LMW-FGF-2 attenuated this response. (C and D) Expression of TIMP-1 and TIMP-2, respectively, at the mRNA levels are presented. TGFβ1 significantly reduced both TIMP-1 and TIMP-2 expression while LMW-FGF-2 partially restored expression. (E) At the protein level, TGFβ1 did not alter TIMP-1, however the presence of LMW-FGF-2 resulted in increased TIMP-1 protein. (F) Though the results for TIMP-2 were not statistically significant, a trend toward decreased TIMP-2 protein was noted in the TGFβ1 group and restored in the presence of LMW-FGF-2. *, p < 0.05.