Fig. 2

Systemic SHED-EV infusion improved bone loss and enhanced osteoclast activity in recipient ovariectomized (OVX) mice. a OVX mice were intravenously administered SHED-EVs (100 μg/mouse) pretreated with carboxyfluorescein diacetate succinimidyl ester (CFSE) 2 days post-surgery. Representative fluorescent micrographs of the bone marrow of OVX mice 3 days after SHED-EV infusion as seen by the cell tracking assay using CFSE-labeled SHED-EVs (CSFE-EVs). Nuclei were stained with 4′,6-diamidino-2-phenylindole (DAPI). Bars = 100 μm. b–d OVX mice were intravenously administered SHED-EVs (100 μg/mouse) pretreated with or without RNase for 30 min 2 days post-surgery and harvested 4 weeks after infusion. Representative trabecular bone structure of the third lumbar vertebra (L3) by the micro-computed tomography assay (b). The graphs show BMD, BV/TV, Tb. N, and Tb. Th of the trabecular bone in L3. n = 7 for all groups. Comparisons between two groups were analyzed by an independent two-tailed Student’s t test. Multiple group comparisons were performed by a one-way analysis of variance followed by Tukey’s post hoc test. *P < 0.05, **P < 0.01, ***P < 0.005, ns no significance. Graph bars represent mean ± standard deviation (SD) (c). Representative trabecular bone structure of L3 by histological assay using hematoxylin and eosin staining (H&E) (d). b–d Sham, sham-operated group; OVX, PBS-infused OVX group; MOCK-EV, MOCK-treated SHED-EV-infused OVX group; RNase-EV, RNase-retreated SHED-EV-infused OVX group. a, b, d Bars = 100 μm (a, left), 20 μm (a, right), 1 mm (b), 200 μm (d)