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Liu Z, Solesio ME, Schaffler MB, Frikha-Benayed D, Rosen CJ, Werner H, Kopchick JJ, Pavlov EV, Abramov AY, Yakar S. Mitochondrial Function Is Compromised in Cortical Bone Osteocytes of Long-Lived Growth Hormone Receptor Null Mice. J Bone Miner Res 2019; 34:106-122. [PMID: 30216544 PMCID: PMC7080402 DOI: 10.1002/jbmr.3573] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/14/2018] [Revised: 08/03/2018] [Accepted: 08/08/2018] [Indexed: 12/12/2022]
Abstract
Despite increased longevity and resistance to multiple stressors, growth hormone receptor null (GHRKO) mice exhibit severe skeletal impairment. The role of GHR in maintaining osteocyte mitochondrial function is unknown. We found that GHR ablation was detrimental to osteocyte mitochondrial function. In vivo multiphoton microscopy revealed significant reductions of >10% in mitochondrial membrane potential (MMP) in GHRKO osteocytes and reduced mitochondrial volumetric density. Reductions in MMP were accompanied by reductions in glucose transporter-1 levels, steady state ATP, NADH redox index, oxygen consumption rate, and mitochondrial reserve capacity in GHRKO osteocytes. Glycolytic capacity did not differ between control and GHRKO males' osteocytes. However, osteocytes from aged female GHRKO mice exhibited reductions in glycolytic parameters, indicating impairments in glucose metabolism, which may be sex dependent. GHRKO osteocytes exhibited increased levels of cytoplasmic reactive oxygen species (ROS) (both basal and in response to high glucose), insulin-like growth factor-1 (IGF-1), and insulin. Mitochondrial ROS levels were increased and correlated with reduced glutathione in GHRKO osteocytes. Overall, the compromised osteocyte mitochondrial function and responses to metabolic insults strongly correlated with skeletal impairments, suggesting that despite increased life span of the GHRKO mice, skeletal health span is decreased. © 2018 American Society for Bone and Mineral Research.
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Affiliation(s)
- Zhongbo Liu
- David B. Kriser Dental Center, Department of Basic Science and Craniofacial Biology, New York University College of Dentistry, New York, NY, USA
| | - Maria E Solesio
- David B. Kriser Dental Center, Department of Basic Science and Craniofacial Biology, New York University College of Dentistry, New York, NY, USA
| | - Mitchell B Schaffler
- Department of Biomedical Engineering, City College of New York, New York, NY, USA
| | - Dorra Frikha-Benayed
- Department of Biomedical Engineering, City College of New York, New York, NY, USA
| | | | - Haim Werner
- Department of Human Molecular Genetics and Biochemistry, Sackler School of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - John J Kopchick
- Edison Biotechnology Institute and Department of Biomedical Sciences, Ohio University, Athens, OH, USA
| | - Evgeny V Pavlov
- David B. Kriser Dental Center, Department of Basic Science and Craniofacial Biology, New York University College of Dentistry, New York, NY, USA
| | - Andrey Y Abramov
- Department of Molecular Neuroscience, UCL Institute of Neurology, Queen Square, London, UK
| | - Shoshana Yakar
- David B. Kriser Dental Center, Department of Basic Science and Craniofacial Biology, New York University College of Dentistry, New York, NY, USA
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Wang S, Wu J, Wang N, Zeng L, Wu Y. The role of growth hormone receptor in β cell function. Growth Horm IGF Res 2017; 36:30-35. [PMID: 28915386 DOI: 10.1016/j.ghir.2017.08.002] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/10/2017] [Revised: 06/10/2017] [Accepted: 08/23/2017] [Indexed: 12/20/2022]
Abstract
Growth hormone (GH) exerts numerous effects on tissues through binding to its receptor, GHR, which resides on cell membranes in many different organs and tissues. Endocrine pancreatic β cells are the only source of insulin secretion in response to metabolic demand, thereby regulating blood glucose and maintaining metabolic homeostasis. β cell dysfunction is the main composition of diabetes mellitus. Numerous studies have provided strong evidence that GHR signaling plays an independent role in β cell function. In this review, we focus on the role of GHR signaling in β cell actions and the underlying molecular mechanisms.
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Affiliation(s)
- Shuang Wang
- Institute of Genome Engineered Animal Models for Human Diseases, Dalian Medical University, Dalian 116044, China
| | - Jin Wu
- Institute of Genome Engineered Animal Models for Human Diseases, Dalian Medical University, Dalian 116044, China
| | - Ning Wang
- Institute of Genome Engineered Animal Models for Human Diseases, Dalian Medical University, Dalian 116044, China
| | - Li Zeng
- Institute of Genome Engineered Animal Models for Human Diseases, Dalian Medical University, Dalian 116044, China.
| | - Yingjie Wu
- Institute of Genome Engineered Animal Models for Human Diseases, Dalian Medical University, Dalian 116044, China.
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