Figure 3.

PPARγ activators troglitazone and 15d-PGJ₂ inhibit MMP-9 expression and gelatinolytic activity in human VSMCs in a concentration-dependent manner. A, Western blot analysis (upper panels) and gelatin zymography (middle panels) on supernatants from human VSMCs after treatment with PMA (50 mg/L) in the presence or absence of troglitazone (trogl) or 15d-PGJ₂ at different concentrations. Lower panel, Densitometric analysis of the MMP-9 gelatinolytic activity in zymograms (solid bars) or MMP-9 protein levels in Western blots (open bars) are shown as percent of PMA-stimulated cells. Results are presented as mean±SEM (n=3). B, PPARγ activators troglitazone (trogl) or 15d-PGJ₂ (both 10 μmol/L) do not affect the expression of TIMP-1 and TIMP-2 in VSMC supernatants as shown by Western blot analysis. C, Northern blot analysis (upper panel) of total RNA of human VSMCs treated with PMA (50 mg/L) in the presence or absence of troglitazone (trogl) or 15d-PGJ₂ (both 10 μmol/L). Ethidium bromide staining of the gel shows similar loading in all lanes (lower panel). Similar results were seen in 3 independent experiments.