Fig. 6

Representative proteins in ULF-EVs whose abundance increased with pregnancy development also significantly increased after ULF-EVs treatment of pTr2 cells. A Western blot analysis of MUC4, ACP5 and MEP1B in ULF-EVs. B Relative abundance of MUC4, ACP5 and MEP1B in pTr2 cells treated with ULF-EVs. C Images of the embryo-maternal interface stained with MEP1B antibodies. MEP1B was obviously expressed in the endometrium and trophoblast. The scale bar indicates 100 nm. D Quantitative analysis of MEP1B by assessing the average integrated optical density (IOD) in the endometrium. The data are displayed as mean ± SD and different lowercase letters correspond to significant differences at the p < 0.05 threshold. E Quantitative analysis of MEP1B by assessing IOD in the trophoblast. Asterisks indicate significant differences (mean ± SD) between 12 and 15P (**p < 0.01). F The relative expression level of MEP1B mRNA was determined by qRT-PCR. The data are displayed as mean ± SD and asterisk indicate significant differences (*p < 0.05)