Fig. 7. NMN increased osteogenesis but decreased adipogenesis of BM MSCs via a SIRT1-dependent pathway.

a As shown in Fig. S4A, representative immunoblot showing SIRT1 expression in LepR⁺CD45⁻Ter119⁻CD31⁻CD51⁺ MSCs from the femur of 15-month-old mice supplemented with NMN (300 mg/kg/day, in drinking water) for 3 months compared with the control (n = 6 mice per group from three independent experiments). b–d As shown in Fig. S4B, clonal differentiation of MSCs from 15-month-old mice with or without a SIRT1 inhibitor (nicotinamide, 10 mM) and/or 0.75 μM NMN, for 1 week during CFU-F formation (b), another 1 week during adipogenic differentiation (c) or another 2 weeks during osteogenic differentiation (d) (n = 6 mice per group from three independent experiments). e–o As shown in Fig. S4C, parameters of femurs from 15-month-old Prx1 cre; ColA1^{flox-stop-flox-SIRT1} and littermate control mice (n = 6 mice per group from six independent experiments). e CFU-F frequency of MSCs from Prx1 cre; ColA1^{flox-stop-flox-SIRT1} and littermate control mice. f Femur length of MSCs from Prx1 cre; ColA1^{flox-stop-flox-SIRT1} and littermate control mice. g Representative µCT images showing trabecular bone in the femur metaphysis of Prx1 cre; ColA1^{flox-stop-flox-SIRT1} and littermate control mice. h–m µCT analyses of the percentage of trabecular bone volume out of total volume (h), trabecular number (i), trabecular thickness (j), trabecular spacing (k), connectivity density (l), and structure model index (m) in the femur metaphysis of Prx1 cre; ColA1^{flox-stop-flox-SIRT1} and littermate control mice. n, o Quantification of adipocyte number (n) and representative Oil Red S and hematoxylin staining in femur sections from Prx1 cre; ColA1^{flox-stop-flox-SIRT1} and littermate control mice (o). *p < 0.05, **p < 0.01 error bars, s.d.