Daily leptin blunts marrow fat but does not impact bone mass in calorie-restricted mice.
The Journal of endocrinology
Adipose Tissue, Adiposity, Animals, Bone Density, Bone Marrow, Bone and Bones, Caloric Restriction, Energy Metabolism, Female, Humans, Leptin, Mice, Mice, Inbred C57BL, Recombinant Proteins, X-Ray Microtomography
Starvation induces low bone mass and high bone marrow adiposity in humans, but the underlying mechanisms are poorly understood. The adipokine leptin falls in starvation, suggesting that hypoleptinemia may be a link between negative energy balance, bone marrow fat accumulation, and impaired skeletal acquisition. In that case, treating mice with leptin during caloric restriction (CR) should reduce marrow adipose tissue (MAT) and improve bone mass. To test this hypothesis, female C57Bl/6J mice were fed a 30% CR or normal (N) diet from 5 to 10 weeks of age, with daily injections of vehicle (VEH), 1mg/kg leptin (LEP1), or 2mg/kg leptin (LEP2) (N=6-8/group). Outcomes included body mass, body fat percentage, and whole-body bone mineral density (BMD) via peripheral dual-energy X-ray absorptiometry, cortical and trabecular microarchitecture via microcomputed tomography (μCT), and MAT volume via μCT of osmium tetroxide-stained bones. Overall, CR mice had lower body mass, body fat percentage, BMD, and cortical bone area fraction, but more connected trabeculae, vs N mice (P
Devlin, M J; Brooks, D J; Conlon, C; Vliet, M van; Louis, L; Rosen, C J.; and Bouxsein, M L, "Daily leptin blunts marrow fat but does not impact bone mass in calorie-restricted mice." (2016). Maine Medical Center. 286.