TGF-β induces TIMP-3 gene expression in a Smad-dependent manner in fibroblasts.

<p>(<b>A</b>) Human gingival fibroblasts were treated with TGF-β1 (5 ng/ml) for 24 h. Thereafter, total cellular RNAs were harvested and analyzed for the expression of TIMP-3, TIMP-1, PAI-1, and GAPDH mRNAs by Northern blotting. (<b>B</b>) EF7WT and EF7Smad4KO (Smad4 deficient) cells were treated with TGF-β1 (5 ng/ml) for 3 h and 12 h or left untreated (control). Total RNA was extracted and TIMP-3 and PAI-1 gene expression was determined by qRT-PCR. mRNA expression (mean+SD) is shown relative to 18S ribosomal RNA (n = 4). *p<0.05, **p<0.005 (t-test) for TGF-β vs. control cultures.