Melatonin Improves the Resistance of Oxidative Stress-Induced Cellular Senescence in Osteoporotic Bone Marrow Mesenchymal Stem Cells

Figure 2

Melatonin treatments protected OVX BMMSCs from H₂O₂-induced premature senescence. OVX BMMSCs were first exposed to H₂O₂ (100 μM) for 2 h and then treated with melatonin (MT) at 1 μM and 100 μM for an additional 72 h. (a, b) Senescent cells were labeled with senescence-associated β-galactosidase (SA-β-gal) staining.  μm. (c) The cell viability of OVX BMMSCs was determined by CCK-8 assays. (d) Analysis of cell cycle distribution showed that melatonin treatments prevented cell cycle arrest in OVX BMMSCs. (e) Melatonin rescued the osteogenic differentiation of H₂O₂-treated OVX BMMSCs. After a 14-day osteogenic induction, the mineralized extracellular matrix was stained by Alizarin Red S (ARS).  μm. (f) Quantification of the stained mineral layers in H₂O₂- and melatonin-treated cells. The values were normalized to those of the untreated OVX BMMSCs. (g) The mRNA levels of osteoblast-specific marker genes, including Runx2, Sp7, and Bglap, were quantified with qRT-PCR using Gapdh as the reference gene for normalization. Values are presented as the of six independent experiments (n) in SA-β-gal staining, eight independent experiments () in cell viability assays, three independent experiments () in cell cycle assays, four independent experiments () in ARS assays, and four independent experiments () in qRT-PCR experiments. Statistically significant differences are indicated by or between the indicated groups. Statistically significant differences are indicated by or between the indicated groups; ^# or ^## versus the CTRL group.

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