Figure 1.

5-LO/LTB₄ signaling is increased around pulmonary vascular adventitial fibroblasts in PAH. A, Plasma LTB₄ concentration in 10 healthy controls and 10 SSc-PAH patients. B, Demography table. C, Representative immunofluorescence images of human lung sections stained with 5-LO (green) and S100A4 (fibroblasts, red) from healthy individuals and SSc-PAH patients. D, Morphometric analysis of images in C. Number of 5-LO positive cells within 5 μm of the pulmonary adventitia. E, Representative immunofluorescence images of lung sections stained with 5-LO (green) and Vimentin (fibroblasts, red) from DMSO (negative control), SU (PH) or SU+bestatin (bestatin-treated) animals. F, Morphometric analysis of E. In A, data are presented in the scatter plots showing minimal to maximal values and all data points. In C, E, DAPI (blue) stains nuclei; differential interference contrast (DIC) highlights alveolar and vascular structures; n=5. Yellow dashed lines indicate the adventitia area. In A, D, F, data are presented as mean ± SEM. (*: p<0.05)