1. PYY is a negative regulator of bone mass and strength.
- Author
-
Leitch VD, Brassill MJ, Rahman S, Butterfield NC, Ma P, Logan JG, Boyde A, Evans H, Croucher PI, Batterham RL, Williams GR, and Bassett JHD
- Subjects
- Animals, Bone Density, Bone Development, Bone Resorption pathology, Bone Resorption physiopathology, Calcification, Physiologic, Cortical Bone blood supply, Cortical Bone ultrastructure, Female, Femur diagnostic imaging, Femur ultrastructure, Male, Mice, Inbred C57BL, Mice, Knockout, Organ Size, Osteoclasts pathology, Porosity, Bone and Bones anatomy & histology, Bone and Bones physiology, Peptide YY metabolism
- Abstract
Objective: Bone loss in anorexia nervosa and following bariatric surgery is associated with an elevated circulating concentration of the gastrointestinal, anorexigenic hormone, peptide YY (PYY). Selective deletion of the PYY receptor Y1R in osteoblasts or Y2R in the hypothalamus results in high bone mass, but deletion of PYY in mice has resulted in conflicting skeletal phenotypes leading to uncertainty regarding its role in the regulation of bone mass. As PYY analogs are under development for treatment of obesity, we aimed to clarify the relationship between PYY and bone mass., Methods: The skeletal phenotype of Pyy knockout (KO) mice was investigated during growth (postnatal day P14) and adulthood (P70 and P186) using X-ray microradiography, micro-CT, back-scattered electron scanning electron microscopy (BSE-SEM), histomorphometry and biomechanical testing., Results: Bones from juvenile and Pyy KO mice were longer (P < 0.001), with decreased bone mineral content (P < 0.001). Whereas, bones from adult Pyy KO mice had increased bone mineral content (P < 0.05) with increased mineralisation of both cortical (P < 0.001) and trabecular (P < 0.001) compartments. Long bones from adult Pyy KO mice were stronger (maximum load P < 0.001), with increased stiffness (P < 0.01) and toughness (P < 0.05) compared to wild-type (WT) control mice despite increased cortical vascularity and porosity (P < 0.001). The increased bone mass and strength in Pyy KO mice resulted from increases in trabecular (P < 0.01) and cortical bone formation (P < 0.05)., Conclusions: These findings demonstrate that PYY acts as a negative regulator of osteoblastic bone formation, implicating increased PYY levels in the pathogenesis of bone loss during anorexia or following bariatric surgery., (Copyright © 2019 The Authors. Published by Elsevier Inc. All rights reserved.)
- Published
- 2019
- Full Text
- View/download PDF