Fig. 4: Hypoxia enhanced the expresssion of 15-LO2/15-HETE in exosomes.

a The expression levels of CD63, TSG101, 15-LO2, and β-actin in the cell lyses and exosomes. b The level of 15-LO2 production, 15-HETE was abundantly expressed in exosomes secreted from hypoxic PAECs. c PAECs were exposed to normoxia or hypoxia for 24 h and the colocalization between 15-LO2 and CD63 was determined by immunofluorescence. Scale bar = 50 μm. d Exosomes extracted from PAECs were prepared for immuno-electron microscope assay. The image showed 15-LO2 was concentrated in the exosomes. Scale bar = 50 nm. e, f The expression levels of HRS and CD63 in 15-LO knockout or wild-type mice were examined by immunofluorescence and western blot. White arrows indicate pulmonary artery. Scale bar = 100 μm. g Immunofluorescence analysis of HRS and CD63 in relative conditioned PAECs. Scale bar = 50 μm. Cell, cell lyses; exo, exosomes; Nor, normoxia; Hyp, hypoxia; N+NC, normoxia plus negative control; N+si, normoxia plus siRNA of 15-LO2; H+NC, hypoxia plus negative control; H+si, hypoxia plus siRNA of 15-LO2; H+NC+15, hypoxia plus negative control and 15-HETE; H+si+15, hypoxia plus siRNA of 15-LO2 and 15-HETE; H + ALOX15^−/−, 15-LO knockout mice under hypoxia; N+ALOX15^−/−, 15-LO knockout mice under normoxia. *p < 0.05, **p < 0.01, and ***p < 0.001. All values are presented as mean ± SD