Journal: Bioactive Materials
Article Title: Sulfated polysaccharide prevents senescent adipocyte-driven osteonecrosis by stem cell fate reprogramming
doi: 10.1016/j.bioactmat.2025.11.039
Figure Lengend Snippet: SCS reprograms the lineage commitment of MSCs after GC treatment and inhibits the generation of primary senescent adipocytes. ( A ) Schematic illustration of the in vitro investigation of SCS targeting the prostaglandin/PPARγ/INK positive feedback loop in MPS-induced primary senescent adipocytes. ( B ) Representative flow cytometry plot showing p16 + senescent cells in adipocytes derived from bone marrow after 14 days of in vivo MPS induction and subsequently treated with SCS in vitro . ( C ) qPCR analysis of 12 senescence-associated markers in primary senescent adipocytes after in vitro SCS treatment. n = 3 biological replicates. ( D ) ELISA analysis of IL-1β levels in adipocyte supernatant following in vitro SCS treatment. n = 6 biological replicates. ( E ) ELISA analysis of secreted prostaglandins PGD2 and PGE2 in adipocytes under different treatment conditions. D-PBS: bone marrow adipocytes isolated from mice treated in vivo with the solvent control DMSO, followed by in vitro treatment with PBS; M-PBS: bone marrow adipocytes isolated from mice treated in vivo with MPS, followed by in vitro treatment with PBS. M-SCS: bone marrow adipocytes isolated from mice treated in vivo with MPS, followed by in vitro treatment with SCS. ( F ) Western blot analysis of intracellular COX-2 protein levels in adipocytes across the three treatment conditions. ( G ) Schematic illustration of competitive osteogenic–adipogenic differentiation of CD45 − Ter119 − CD31 − LepR + MSCs after 7 days of in vivo SCS and MPS co-treatment. ( H ) qPCR analysis of pan-adipocyte markers ( Fabp4 , Adipoq , Plin1 , Cd36 , and Lep ) in CD45 − Ter119 − CD31 − LepR + MSCs after 14 days of in vitro competitive lineage differentiation. n = 3 biological replicates. ( I and J ) Representative immunofluorescence images (I) and quantification (J) of perilipin + adipocytes and osteopontin + mature osteoblasts derived from lineage-committed MSCs. n = 6 biological replicates. (Scale bars, 30 μm, 15 μm and 15 μm). ( K ) Western blot analysis of adipogenesis-related markers C/EBPα, PPARγ, and C/EBPβ in the lineage-mixed cells after in vitro competitive differentiation of CD45 − Ter119 − CD31 − LepR + MSCs. ( L ) qPCR analysis of lipogenesis-related markers Fasn , Scd1 , Srebf1 , Acaca , and Acacb . n = 3 biological replicates. ( M and N ) Representative H&E staining images (M) of the femurs at day 14 following SCS and MPS co-treatment. Yellow arrows indicate bone marrow adipocytes. Magnified images show hypertrophic adipocyte morphology, with quantification of adipocyte diameter (N). n = 19 biological replicates. (Scale bars, 200 μm, 50 μm and 20 μm). Data are presented as mean ± SD. ∗ p < 0.05, ∗∗ p < 0.01, ∗∗∗ p < 0.001, ∗∗∗∗ p < 0.0001; ns, not significant. Statistical significance was determined using an unpaired two-tailed Student's t -test ( C, D, H, J, L and N ), or one-way ANOVA with Tukey's post hoc test ( E ).
Article Snippet: To further investigate the anti-senescent effects of SCS on primary senescent adipocytes, ELISA was performed on adipocyte supernatant to quantify senescence-associated factors including IL-1β (Neobioscience, EMC001b.96), IL-18 (Neobioscience, EMC011.96), TNF-α (Neobioscience, EMC102a.96), and prostaglandins PGJ2 (NOVUS, NBP2-61285), PGD2 (Cayman Chemical, 500151), and PGE2 (R&D Systems, KGE004B).
Techniques: In Vitro, Flow Cytometry, Derivative Assay, In Vivo, Enzyme-linked Immunosorbent Assay, Isolation, Solvent, Control, Western Blot, Immunofluorescence, Staining, Two Tailed Test