LRG1 and osteoporosis: To further verify the mechanism and the therapeutic potential of sEV-LRG1 in osteoporosis in vivo, we consecutively intravenously injected the mice with control-sEVs (NC-sEVs), shSIRT2-sEVs and shSIRT2-shLRG1-sEVs (50 μg per mouse, every other day) 3 d after OVX (Fig. 4f).