Fig. 4
A2bR knockdown cells and PKA inhibitor reverse the stimulatory effect of CD73+hucMSC-EVs. A–F BV2 cells are permanently transfected with scrambled shRNA or A2bR shRNA. Cells are then treated with 1 μg/ml LPS or 5 μg/ml IL-4 in the presence or absence of 30 μg/ml CD73+ hucMSC-EVs. A and B Intracellular cAMP levels are measured after 10 min stimulation (n = 5). PKA protein expression is detected (n = 3). C and D The iNOS/Arg-1 protein expression in BV2 cells is investigated. E and F The mRNA relative expression level of M1/M2 phase is either detected. (*p < 0.05 versus shRNA scrambled/A2bR + LPS, #p < 0.05 versus shRNA scrambled + CD73 + hucMSC-EVs). G and H The iNOS/Arg-1 protein expression in BV2 cells is investigated in presence or absence of 10 μM H-89 (PKA inhibitor)