Figure 2.

ET-1 induced cell proliferation and overexpression of myofibroblast markers through the ET_AR subtype. Cells were pretreated without or with ambrisentan (ET_AR antagonist; 1 µM), BQ-788 (ET_BR antagonist; 1 µM) or ambrisentan plus BQ-788 for 1 h before treatment with ET-1 for 24 h (A–C) or 12 h (D). (A) Cell proliferation was calculated as percentage relative to control group. (B) Cells were stained for Ki-67 (green) and nucleus DAPI (blue). Scale bar, 10 µm. Proliferative capacity was calculated as the percentage of Ki-67-positive cells. (C) α-SMA protein expression was visualized by fluorescent microscope. Cells were stained for α-SMA (green) and nucleus DAPI (blue). Scale bar, 10 µm. (D) Relative α-SMA and collagen I mRNA levels analyzed by qRT-PCR were calculated as the fold over the vehicle-treated group. Data were expressed as the mean ± SD. (n = 4). * p < 0.05 vs. vehicle; ^# p < 0.05 vs. ET-1.