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Leitch VD, Brassill MJ, Rahman S, Butterfield NC, Ma P, Logan JG, Boyde A, Evans H, Croucher PI, Batterham RL, Williams GR, Bassett JHD. PYY is a negative regulator of bone mass and strength. Bone 2019; 127:427-435. [PMID: 31306808 PMCID: PMC6715792 DOI: 10.1016/j.bone.2019.07.011] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/15/2019] [Revised: 07/03/2019] [Accepted: 07/11/2019] [Indexed: 02/02/2023]
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.
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Affiliation(s)
- Victoria D Leitch
- Molecular Endocrinology Laboratory, Department of Medicine, Hammersmith Campus, Imperial College London, London W12 0NN, United Kingdom
| | - Mary Jane Brassill
- Molecular Endocrinology Laboratory, Department of Medicine, Hammersmith Campus, Imperial College London, London W12 0NN, United Kingdom
| | - Sofia Rahman
- Centre for Obesity Research, University College London, London WC1E 6JF, United Kingdom
| | - Natalie C Butterfield
- Molecular Endocrinology Laboratory, Department of Medicine, Hammersmith Campus, Imperial College London, London W12 0NN, United Kingdom
| | - Pattara Ma
- Molecular Endocrinology Laboratory, Department of Medicine, Hammersmith Campus, Imperial College London, London W12 0NN, United Kingdom
| | - John G Logan
- Molecular Endocrinology Laboratory, Department of Medicine, Hammersmith Campus, Imperial College London, London W12 0NN, United Kingdom
| | - Alan Boyde
- Queen Mary University of London, Oral BioEngineering, Bart's and The London School of Medicine and Dentistry, London E1 4NS, United Kingdom
| | - Holly Evans
- Sheffield Myeloma Research Team, University of Sheffield, Sheffield S10 2RX, United Kingdom
| | - Peter I Croucher
- The Garvan Institute of Medical Research and St. Vincent's Clinical School, University of New South Wales Medicine, Sydney, New South Wales 2010, Australia
| | - Rachel L Batterham
- Centre for Obesity Research, University College London, London WC1E 6JF, United Kingdom; National Institute of Health Research, University College London Hospitals Biomedical Research Centre, London Q1T 7DN, United Kingdom
| | - Graham R Williams
- Molecular Endocrinology Laboratory, Department of Medicine, Hammersmith Campus, Imperial College London, London W12 0NN, United Kingdom.
| | - J H Duncan Bassett
- Molecular Endocrinology Laboratory, Department of Medicine, Hammersmith Campus, Imperial College London, London W12 0NN, United Kingdom.
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