Journal: Stem Cell Research & Therapy

Article Title: BMSC-derived exosomes facilitate osteogenesis and ameliorate ageing-related bone loss through restoring Th17/Treg homeostasis via the miR-21/Skp2/FoxO1 axis

doi: 10.1186/s13287-026-04927-4

Figure Lengend Snippet: BMSC-exosomes facilitate osteogenic differentiation of MC3T3-E1 cells and ameliorate age-related bone loss in SAMP6 cells. A ALP staining of MC3T3-E1 cells treated with PBS or BMSC-exosomes; B mRNA levels of osteogenesis-related markers in PBS- or BMSC-exosome-treated MC3T3-E1 cells, as determined by qRT‒PCR analysis. C representative micro-CT images of femurs from SAMR1 mice, SAMP6 mice, and PBS- or BMSC-exosome-treated SAMP6 mice; D – G quantitative analysis of bone parameters; H representative H&E-stained femoral sections from SAMR1 mice, SAMP6 mice, and PBS- or BMSC-exosome-treated SAMP6 mice across different groups. n = 6 per group for mice, n = 3 per group for cells; the data are expressed as the means ± SDs; * p < 0.05, ** p < 0.01, *** p < 0.001

Article Snippet: MC3T3-E1 cells were randomly divided into the following groups: (1) MC3T3-E1 cells treated with PBS; (2) MC3T3-E1 cells with BMSC-exosome treatment; (3) MC3T3-E1 cells treated with exosomes derived from NC inhibitor-transfected BMSCs; (4) MC3T3-E1 cells treated with exosomes derived from miR-21-5p inhibitor-transfected BMSCs; (5) MC3T3-E1 cells treated with exosomes derived from miR-21-5p inhibitor-transfected BMSCs and DMSO; (6) MC3T3-E1 cells treated with exosomes derived from miR-21-5p inhibitor-transfected BMSCs and SKPin C1 (50 μM, S8652, Selleck, China); (7) pcDNA3 vector-transfected MC3T3-E1 cells treated with exosomes derived from miR-21-5p inhibitor-transfected BMSCs; and (8) pcDNA3-FoxO1-transfected MC3T3-E1 cells treated with exosomes derived from miR-21-5p inhibitor-transfected BMSCs.

Techniques: Staining, Micro-CT

Journal: Stem Cell Research & Therapy

Article Title: BMSC-derived exosomes facilitate osteogenesis and ameliorate ageing-related bone loss through restoring Th17/Treg homeostasis via the miR-21/Skp2/FoxO1 axis

doi: 10.1186/s13287-026-04927-4

Figure Lengend Snippet: miR-21-5p delivered by BMSC-exosomes promotes osteogenic differentiation and ameliorates ageing-related bone loss. The expression levels of miR-21-5p were determined by qRT‒PCR in A BMSCs and BMSC-derived exosomes; B MC3T3-E1 cells treated with either PBS or BMSC-derived exosomes; C NC inhibitor- or miR-21-5p inhibitor-transfected BMSCs; D exosomes isolated from NC inhibitor- or miR-21-5p inhibitor-transfected BMSCs. E ALP staining of MC3T3-E1 cells following treatment with exosomes derived from NC inhibitor- or miR-21-5p inhibitor-transfected BMSCs. F protein expression levels of osteogenesis-related markers in MC3T3-E1 cells treated with exosomes from inhibitor-transfected BMSCs, as assessed by western blotting. G the expression levels of miR-21-5p were determined by qRT‒PCR in femoral tissues from SAMP6 and SAMR1 mice, as well as from SAMP6 mice treated with PBS or BMSC-derived exosomes. H representative micro-CT images of femurs from SAMP6 mice treated with exosomes derived from BMSCs transfected with either the NC inhibitor or the miR-21-5p inhibitor. I – L quantitative analysis of bone morphometric parameters; M representative H&E-stained femoral sections from the corresponding treatment groups. n = 6 per group for mice, n = 3 per group for cells; the data are presented as the means ± SDs; statistical significance was set at * p < 0.05, ** p < 0.01, and *** p < 0.001

Article Snippet: MC3T3-E1 cells were randomly divided into the following groups: (1) MC3T3-E1 cells treated with PBS; (2) MC3T3-E1 cells with BMSC-exosome treatment; (3) MC3T3-E1 cells treated with exosomes derived from NC inhibitor-transfected BMSCs; (4) MC3T3-E1 cells treated with exosomes derived from miR-21-5p inhibitor-transfected BMSCs; (5) MC3T3-E1 cells treated with exosomes derived from miR-21-5p inhibitor-transfected BMSCs and DMSO; (6) MC3T3-E1 cells treated with exosomes derived from miR-21-5p inhibitor-transfected BMSCs and SKPin C1 (50 μM, S8652, Selleck, China); (7) pcDNA3 vector-transfected MC3T3-E1 cells treated with exosomes derived from miR-21-5p inhibitor-transfected BMSCs; and (8) pcDNA3-FoxO1-transfected MC3T3-E1 cells treated with exosomes derived from miR-21-5p inhibitor-transfected BMSCs.

Techniques: Expressing, Derivative Assay, Transfection, Isolation, Staining, Western Blot, Micro-CT

Journal: Stem Cell Research & Therapy

Article Title: BMSC-derived exosomes facilitate osteogenesis and ameliorate ageing-related bone loss through restoring Th17/Treg homeostasis via the miR-21/Skp2/FoxO1 axis

doi: 10.1186/s13287-026-04927-4

Figure Lengend Snippet: BMSC exosomal miR-21-5p directly targets SKP2. A Predicted binding site of miR-21-5p within the 3′UTR of SKP2 mRNA using TargetScan; luciferase activity assays validating the direct interaction between miR-21-5p and SKP2. Western blot analysis of SKP2 expression in B MC3T3-E1 cells treated with PBS or BMSC-derived exosomes; C femoral tissue from SAMR1, SAMP6, and PBS- or BMSC-exosome-treated SAMP6 mice; D MC3T3-E1 cells treated with exosomes derived from cells transfected with the NC inhibitor or miR-21-5p inhibitor; E femoral tissue from SAMP6 mice treated with exosomes derived from NC inhibitor- or miR-21-5p inhibitor-transfected BMSCs. F SKP2 protein levels in MC3T3-E1 cells treated with exosomes from miR-21-5p inhibitor-transfected BMSCs in combination with DMSO or SKPin C1. G ALP staining of MC3T3-E1 cells under the same treatment conditions. H protein expression levels of osteogenic markers in MC3T3-E1 cells following the indicated treatments. n = 6 per group for mice, n = 3 per group for cells; the data are expressed as the means ± SDs; * p < 0.05, ** p < 0.01, *** p < 0.001

Article Snippet: MC3T3-E1 cells were randomly divided into the following groups: (1) MC3T3-E1 cells treated with PBS; (2) MC3T3-E1 cells with BMSC-exosome treatment; (3) MC3T3-E1 cells treated with exosomes derived from NC inhibitor-transfected BMSCs; (4) MC3T3-E1 cells treated with exosomes derived from miR-21-5p inhibitor-transfected BMSCs; (5) MC3T3-E1 cells treated with exosomes derived from miR-21-5p inhibitor-transfected BMSCs and DMSO; (6) MC3T3-E1 cells treated with exosomes derived from miR-21-5p inhibitor-transfected BMSCs and SKPin C1 (50 μM, S8652, Selleck, China); (7) pcDNA3 vector-transfected MC3T3-E1 cells treated with exosomes derived from miR-21-5p inhibitor-transfected BMSCs; and (8) pcDNA3-FoxO1-transfected MC3T3-E1 cells treated with exosomes derived from miR-21-5p inhibitor-transfected BMSCs.

Techniques: Binding Assay, Luciferase, Activity Assay, Western Blot, Expressing, Derivative Assay, Transfection, Staining

Journal: Stem Cell Research & Therapy

Article Title: BMSC-derived exosomes facilitate osteogenesis and ameliorate ageing-related bone loss through restoring Th17/Treg homeostasis via the miR-21/Skp2/FoxO1 axis

doi: 10.1186/s13287-026-04927-4

Figure Lengend Snippet: BMSC-derived exosomal miR-21-5p stabilizes FoxO1 by inhibiting Skp2-mediated ubiquitination and degradation. Western blot analysis was used to assess FoxO1 expression in A MC3T3-E1 cells treated with PBS or BMSC-derived exosomes; B MC3T3-E1 cells treated with exosomes derived from control inhibitor- or miR-21-5p inhibitor-transfected BMSCs; C femurs of SAMR1, SAMP6, and SAMP6 mice treated with PBS or BMSC-derived exosomes; D femurs of SAMP6 mice treated with exosomes from control inhibitor- or miR-21-5p inhibitor-transfected BMSCs. The ubiquitination levels of FoxO1 were analysed in E MC3T3-E1 cells treated with PBS or BMSC-derived exosomes and F MC3T3-E1 cells treated with exosomes from control inhibitor- or miR-21-5p inhibitor-transfected BMSCs. G FoxO1 expression in MC3T3-E1 cells treated with exosomes from miR-21-5p inhibitor-transfected BMSCs in the presence or absence of SKPin C1 was determined by western blotting. n = 6 per group/for mice; n = 3 per group for cells; the data are presented as the means ± SDs; * p < 0.05, ** p < 0.01, *** p < 0.001

Article Snippet: MC3T3-E1 cells were randomly divided into the following groups: (1) MC3T3-E1 cells treated with PBS; (2) MC3T3-E1 cells with BMSC-exosome treatment; (3) MC3T3-E1 cells treated with exosomes derived from NC inhibitor-transfected BMSCs; (4) MC3T3-E1 cells treated with exosomes derived from miR-21-5p inhibitor-transfected BMSCs; (5) MC3T3-E1 cells treated with exosomes derived from miR-21-5p inhibitor-transfected BMSCs and DMSO; (6) MC3T3-E1 cells treated with exosomes derived from miR-21-5p inhibitor-transfected BMSCs and SKPin C1 (50 μM, S8652, Selleck, China); (7) pcDNA3 vector-transfected MC3T3-E1 cells treated with exosomes derived from miR-21-5p inhibitor-transfected BMSCs; and (8) pcDNA3-FoxO1-transfected MC3T3-E1 cells treated with exosomes derived from miR-21-5p inhibitor-transfected BMSCs.

Techniques: Derivative Assay, Ubiquitin Proteomics, Western Blot, Expressing, Control, Transfection

Journal: Stem Cell Research & Therapy

Article Title: BMSC-derived exosomes facilitate osteogenesis and ameliorate ageing-related bone loss through restoring Th17/Treg homeostasis via the miR-21/Skp2/FoxO1 axis

doi: 10.1186/s13287-026-04927-4

Figure Lengend Snippet: Upregulation of FoxO1 expression rescues the impairment of osteogenic differentiation and Th17/Treg balance caused by miR-21-5p suppression. A Western blot analysis of FoxO1 expression in MC3T3-E1 cells transfected with an empty vector or a FoxO1 overexpression plasmid. B ALP staining of MC3T3-E1 cells under the indicated treatment conditions. C the protein expression levels of osteogenic markers (ALP, Bglap, and Runx2) were measured by western blotting. D western blot validation of FoxO1 expression in CD4⁺ T cells transfected with empty vector or FoxO1 overexpression plasmids. E flow cytometric analysis of Th17 and Treg cell populations among FoxO1-overexpressing CD4(+) T cells treated with exosomes derived from BMSCs transfected with a miR-21-5p inhibitor. n = 3; Data are presented as the means ± SDs; * p < 0.05, ** p < 0.01, *** p < 0.001

Article Snippet: MC3T3-E1 cells were randomly divided into the following groups: (1) MC3T3-E1 cells treated with PBS; (2) MC3T3-E1 cells with BMSC-exosome treatment; (3) MC3T3-E1 cells treated with exosomes derived from NC inhibitor-transfected BMSCs; (4) MC3T3-E1 cells treated with exosomes derived from miR-21-5p inhibitor-transfected BMSCs; (5) MC3T3-E1 cells treated with exosomes derived from miR-21-5p inhibitor-transfected BMSCs and DMSO; (6) MC3T3-E1 cells treated with exosomes derived from miR-21-5p inhibitor-transfected BMSCs and SKPin C1 (50 μM, S8652, Selleck, China); (7) pcDNA3 vector-transfected MC3T3-E1 cells treated with exosomes derived from miR-21-5p inhibitor-transfected BMSCs; and (8) pcDNA3-FoxO1-transfected MC3T3-E1 cells treated with exosomes derived from miR-21-5p inhibitor-transfected BMSCs.

Techniques: Expressing, Western Blot, Transfection, Plasmid Preparation, Over Expression, Staining, Biomarker Discovery, Derivative Assay