Figure 7: In vitro, the HDC/histamine axis regulates TGF-β1 and VEGF signaling via H1HR and H2HR-mediated pathways, respectively.
Histamine treatment increased the expression of H1HR and H2HR that was subsequently blocked when the respective receptor was inhibited (A-B). Biliary TGF-β1 expression and VEGF-C expression increased after histamine treatment shown by immunofluorescence (C and D). Inhibition of H1HR decreased TGF-β1 expression (C), whereas blocking H2HR decreased VEGF-C expression (D). Data are mean ± SEM of n = 9 experiments for qPCR. *p<0.05 vs. basal; #p<0.05 vs. histamine treatment. Representative images x20.