H&E staining results showed that compared with the mimic NC-GMNPE-EVs + oe-NC group, the DO rat metaphyseal trabeculae in the miR-15b-5p overexpressed group were thicker, more arranged and denser, with clear and intact structures, and less depressed areas, indicating a relief of osteoporosis; compared with the miR-15b-5p-mimic-GMNPE-EVs + oe-NC group, the DO rat metaphyseal trabeculae in the further overexpressed GFAP-treated group were thinner, with loose structures, more significant gaps at the junctions, expanded depressed areas, and aggravated osteoporosis (Fig. 8C-D). This evidence concerns the gene GFAP and osteoporosis.