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. 2013 Sep 11;8(9):e74094. doi: 10.1371/journal.pone.0074094

Figure 1. HTRA1 inhibits TGF-β-mediated transcription.

Figure 1

(A) The effect of HTRA1 on TGF-β transcription was examined by co-transfecting HeLa cells with a luciferase reporter plasmid driven by tandem Smad responsive elements and with either control plasmid or 0, 25, 50, 100 or 150 ng of a plasmid that overexpresses HTRA1. After 24 hours, cells were either left untreated or treated with 10 ng/ml TGF-β for 16 hours to induce the Smad-responsive reporter gene. Relative luciferase activity was determined by calculating the ratio of firefly and Renilla luciferase activities. (B) The effect of exogenous treatment of HTRA1 on TGF-β-mediated transcription. HeLa cells were transfected with a Smad-responsive reporter and then either left untreated or treated with the indicated concentrations of purified HTRA1 or an inactive mutant, S328A. Relative luciferase activity was determined by calculating the ratio of firefly and Renilla luciferase activities. (C) TGF-β-induced expression of PAI-1 mRNA. HeLa cells were transfected with either a control plasmid or an HTRA1 plasmid, and then treated with 10 ng/ml of TGF-β for the indicated times. (D) Expression of PAI-1 mRNA in HeLa cells transfected with either a nonspecific control siRNA or with HTRA1 siRNA, then treated with 10 ng/ml of TGF-β for the indicated times. *P<0.05, **P<0.01, ***P<0.001, compared to TGF-β treated control (A, B), or empty plasmid and non-specific siRNA controls (C, D). Student’s t-test, n = 3.