Primary antibody against α sma clone 1a4

Cells were plated on glass coverslips, treated with GI254023X (20 nM) or TGF-β as described, and fixed with 4% PFA for 10-15 min. The cells were then washed three times with PBS, blocked for one hour in blocking solution (10% goat serum; 0.1% triton-X in PBS) and incubated overnight at 4°C with a primary antibody against α-SMA (clone 1A4, Sigma-Aldrich; 1:100 in blocking solution). The next day, samples were washed three times with PBS and incubated for one hour with goat anti-mouse Alexa Fluor 488 and rhodamine phalloidin antibodies (Thermo Fisher Scientific) diluted 1:400 and 1:200, respectively, in blocking solution. Samples were washed three times with PBS and mounted with Vectashield antifade mounting medium with DAPI (Vectorlabs). Images were acquired with a Zeiss LSM780 confocal microscope (Zeiss).