Myocardin-related transcription factor signaling controls cell shape-dependent induction of αSMA by TGFβ1.
(A) Immunofluorescence staining for nuclei and MRTF-A in TGFβ1-treated NMuMG cells cultured on 400 μm2 and 2500 μm2 squares. (B) Quantification of the percentage of cells with nuclear (N), pan-cellular (N/C), and cytoplasmic (C) MRTF-A as a function of cell spread area. (C) Quantification of the percentage of cells expressing αSMA after simultaneous treatment with TGFβ1 and ethanol vehicle or CCG-1423. *p < 0.01; ***p < 0.001 compared to ethanol control. Overexpression of Flag-tagged MRTF-A and Flag-tagged MRTF-A-ΔN increase the expression of αSMA. (D) Quantification of the percentage of cells expressing αSMA for YFP, MRTF-A, MRTF-A-ΔC, and MRTF-A-ΔN transfected NMuMG cells treated with TGFβ1 or control vehicle. ***p < 0.001 compared to YFP. Scale bars: 25 μm.