Fig. 3. ECM crosslinking by TG2 affects production of active MMP-2. Mock, TG2 sense, TG2 antisense and TG2 C277S mutant transfected HCA2 fibroblasts were cultured in 0.5 mg/ml collagen I lattices, and conditioned media from day 7 and 14 cultures were analysed for gelatinase and TIMP activity by gelatin zymography (A) and reverse zymography (B), respectively. The position of the 72 kDa proform and 62 kDa activated forms of MMP-2 as well as TIMP-1, -2 and -3 are indicated on the right. An unidentified higher molecular mass band with TIMP activity, presumably a TIMP complex, is indicated with an asterisk. Molecular mass standards (kDa) are indicated on the left. (C) Densitometric analysis of the relative levels of pro- and active MMP-2 in conditioned medium after 14 day in culture. Values are the mean±s.e.m. of two independent experiments.