Epicardial proliferation is regulated by Hh signalling. a, Freshly dissected tcf21: nuceGFP hearts were randomly separated into two groups and cultured for 47 h with vehicle (n = 11) or 5 uM Cyclopamine (n = 8). Then, 25 uM EdU was added to the medium for 1 h before collection at 48 h. Cyclopamine treatment decreases epicardial cell proliferation ex vivo. Arrows indicate representative eGFP+ (green) EdU+ (red) nuclei. b, Quantification of eGFP+EdU+ nuclei on the ventricular surface, from hearts in a. **P < 0.01, Student's two-tailed t-test. c, tcf21: nuceGFP adult fish were subjected to partial ventricular resection surgery, and randomly separated into two groups for treatment with vehicle (n = 8) or 10 uM Cyclopamine (n = 10) from 2 to 3 dpa. Then, 10 mM EdU was injected intraperitoneally 1 h before collection. Cyclopamine treatment decreases epicardial cell proliferation in vivo. Arrowheads indicate representative eGFP+ (green) EdU+ (red) nuclei. d, Quantification of eGFP+EdU+ nuclei on the ventricular surface, from hearts in c. ***P < 0.001; Mann-Whitney rank sum test. c, Yellow dashed lines indicate resection plane; white dashed lines delineate ventricle. a, c, Boxed areas, magnified views. Scale bars, 50 um. Error bars indicate s.d.
FRA1 downregulation during RAFi treatment drives the reactive secretome.c, In A375 cells treated in vitro with vehicle or vemurafenib for 6 or 48 h. Relative mRNA levels of FRA1 during vemurafenib exposure [0.1-1 uM]. d, Representative immunofluorescence staining of A375/A375R tumours for GFP (A375R, green) and FRA1 (red) after vehicle or vemurafenib treatment (5 days). DAPI, 4',6-diamidino-2-phenylindole. Scale bars, 50 um.