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

Figure 8

Injection of sirtinol aggravated bone loss in melatonin-treated OVX rats. OVX rats were injected with melatonin (MT, 10 mg/kg) or sirtinol (1 mg/kg) through the tail vein. (a) Micro-CT and 3D reconstruction were used to analyze the trabecular bone microstructure. (b) The effect of sirtinol treatment on bone mineral density (BMD). (c) Representative histological images of rat femurs stained by hematoxylin and eosin (H&E).  μm. (d, e) BMMSCs were isolated from melatonin- and sirtinol-treated OVX rats, exposed to H₂O₂ (100 μM) for 2 h, and cultured for an additional 72 h. The protein levels of SIRT1, P16, P21, and P53 were determined using Western blot assays. (f) BMMSCs derived from melatonin- or sirtinol-treated OVX rats were induced toward osteogenic differentiation. Matrix mineralization was assessed by Alizarin Red S (ARS) staining. Scale bar =200 μm. (G) The stained mineral layers were quantified. The values shown were normalized to those of the sham group. Values are presented as the of ten samples in each group () in micro-CT and 3D reconstruction assays, four independent experiments () in ARS assays, and three independent experiments () in Western blot assays. Statistically significant differences are indicated by or between the indicated groups; ^# or ^## versus the sham group.

(a)

(b)

(c)

(d)

(e)

(f)

(g)