Fig. 5.

MiR-181c in hUCMSC-exosomes mediated the alleviation of TLR4 signaling in severe burn rats. 30% TBSA full-thickness burn rats were intravenously injected with hUCMSC-exosomes, miR-181C-exosomes, miR-NC-exosomes or PBS. Rats were sacrificed, and serum and skin wound tissues were collected 24 h after administration.

(A). Quantitative analysis for relative miR-181c expression in hUCMSCs transfected with miR-181c. Data are shown as mean ± SD, n = 3.

(B). Total WBCs in severe burn rats were detected 24 h after treatment with hUCMSC-exosomes, miR-181C-exosomes, miR-NC-exosomes or PBS. Data are shown as mean ± SD, n = 6 for each treatment.

(C–D). Quantitative analysis for relative TLR4 levels (C) and miR-181c levels (D) in cutaneous wounds from severe burn rats after intravenous injection of hUCMSC-exosomes, miR-181C-exosomes, miR-NC-exosomes or PBS at 24 h. Data are shown as mean ± SD, n = 6 for each treatment.

(E). Western blot assay for TLR4 expression and downstream target proteins NF-κB/P65, and p-P65 in cutaneous wounds from severe burn rats after the indicated treatment for 24 h. And the relative protein level of TLR4 is quantified using Image J software.

(F–H). ELISA analysis of TNF-α (F), IL-1β (G) and IL-10 (H) serum levels in severe burn rats after 24 h. Data are shown as mean ± SD, n = 6 for each treatment.

(I). Representative histological micrograph analysis (HE stain) and positive MPO and CD68 staining of cutaneous wounds after the indicated treatment for 24 h. And the quantitive assay is done using Image Pro Plus software.