Fig. 3.

Extracellular vesicle transfer of miR-141-3p up-regulates the JAK-STAT pathway through modulating SOCS5 in endothelial cells. a The relative miR-141 levels determined by RT-qPCR in TD-sEVs and NT-sEVs as well as their corresponding donor cells. (b, c) sEV transfer of miR-141 led to a significant and time-dependent increase in VEGFR-2 mRNA expression. b Transfer of miR-141 was determined by RT-qPCR in HUVECs incubated with both TD-sEVs and α-amanitin compared to α-amanitin only treated cells (negative control) at time points 0, 12 and 24 h. c Mean normalized ratios for VEGFR-2 transcript levels measured by RT-qPCR in HUVECs treated with 100 μg/ml TD-sEVs (compared to PBS-treated control cells) at different time points. d sEV transfer of miR-141-3p caused the up-regulation of VEGFR-2 expression in endothelial cells. RT-qPCR data showed that the VEGFR-2 transcript levels in HUVECs treated with anti-miR-141-3p along with either TD-sEVs or vehicle control (PBS) were significantly lower than those of cells only treated with TD-sEVs. A significant reduction in VEGFR-2 expression in anti-miR-141-3p-transfected HUVECs was also found compared with a scramble-transfected negative control. e-f TD-sEVs up-regulates the JAK-STAT pathway via down-regulating SOCS5 in HUVECs. e Mean normalized ratios for SOCS5 transcript levels measured by RT-qPCR showed that TD-sEV-shuttled miR-141-3p caused down-regulation of SOCS5 expression in HUVECs. Importantly, the inhibitory effect of TD-sEVs on SOCS5 expression level was partially rescued when TD-sEVs-treated endothelial cells transfected along with anti-miR-141. f Mean normalized ratios for JAK1 and STAT3 transcript levels measured by RT-qPCR in TD-sEVs-treated HUVECs transfected with either anti-miR-141-3p or scramble negative control. Results proposed that JAK1 and STAT3 transcript expression levels were significantly increased in TD-sEVs-stimulated HUVECs, while in the presence of anti-miR-141-3p, the promoting effect of TD-sEVs on the JAK1 and STAT3 expression levels was partially diminished. Columns represent means of three different experiments; bars represent SD. ns: non-significant, **P < 0.01, ***P < 0.001