Vascular structures on de-cellularized matrix express active MMPs.

(A) qRT-PCR illustrated up-regulated expression of MMPs in CLS (ECs on ECM) as compared to ECs cultured on tissue culture plastic. Significance was assessed based on the following p values: *p≤0.05; **p≤0.01; ***p≤0.001. (Bi) Western blot did not detect differences in the expression of MT1-MMP between control ECs and CLS. (Bii) Enzyme zymography revealed the expression of the active form of MMP2 and the pro-form of MMP9 in CLS. (Biii) Active forms of MMP1 were observed in control ECs and CLS although CLS contained additional bands of active forms.