Mitochondrial Function Is Compromised in Cortical Bone Osteocytes of Long‐Lived Growth Hormone Receptor Null Mice

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.

[1]  C. Heiss,et al.  Osteocytes Osteozyten , 2018, Zeitschrift für Orthopädie und Unfallchirurgie.

[2]  J. Kopchick,et al.  MECHANISMS IN ENDOCRINOLOGY: Lessons from growth hormone receptor gene-disrupted mice: are there benefits of endocrine defects? , 2018, European journal of endocrinology.

[3]  Nidhi Agrawal,et al.  Ablation of Hepatic Production of the Acid-Labile Subunit in Bovine-GH Transgenic Mice: Effects on Organ and Skeletal Growth , 2017, Endocrinology.

[4]  M. Schaffler,et al.  Regional differences in oxidative metabolism and mitochondrial activity among cortical bone osteocytes. , 2016, Bone.

[5]  S. Yakar,et al.  Regulation of skeletal growth and mineral acquisition by the GH/IGF-1 axis: Lessons from mouse models. , 2016, Growth hormone & IGF research : official journal of the Growth Hormone Research Society and the International IGF Research Society.

[6]  A. Bartke,et al.  The somatotropic axis and aging: Benefits of endocrine defects. , 2016, Growth hormone & IGF research : official journal of the Growth Hormone Research Society and the International IGF Research Society.

[7]  R. Jilka,et al.  The Role of Osteocytes in Age-Related Bone Loss , 2016, Current Osteoporosis Reports.

[8]  O. Kennedy,et al.  DMP‐1 ‐mediated Ghr gene recombination compromises skeletal development and impairs skeletal response to intermittent PTH , 2016, FASEB journal : official publication of the Federation of American Societies for Experimental Biology.

[9]  G. López-Lluch,et al.  Calorie restriction as an intervention in ageing , 2016, The Journal of physiology.

[10]  Yimin Fang,et al.  Transcriptome profiling reveals divergent expression shifts in brown and white adipose tissue from long-lived GHRKO mice , 2015, Oncotarget.

[11]  G. Karsenty,et al.  Glucose Uptake and Runx2 Synergize to Orchestrate Osteoblast Differentiation and Bone Formation , 2015, Cell.

[12]  A. Bartke,et al.  Interaction of growth hormone receptor/binding protein gene disruption and caloric restriction for insulin sensitivity and attenuated aging , 2014, F1000Research.

[13]  H. Brown-Borg,et al.  Growth hormone alters the glutathione S-transferase and mitochondrial thioredoxin systems in long-living Ames dwarf mice. , 2014, The journals of gerontology. Series A, Biological sciences and medical sciences.

[14]  O. Kennedy,et al.  Serum IGF‐1 Is Insufficient to Restore Skeletal Size in the Total Absence of the Growth Hormone Receptor , 2013, Journal of bone and mineral research : the official journal of the American Society for Bone and Mineral Research.

[15]  A. Lewiński,et al.  Decreased levels of proapoptotic factors and increased key regulators of mitochondrial biogenesis constitute new potential beneficial features of long-lived growth hormone receptor gene-disrupted mice. , 2013, The journals of gerontology. Series A, Biological sciences and medical sciences.

[16]  A. Bartke,et al.  The role of GH in adipose tissue: lessons from adipose-specific GH receptor gene-disrupted mice. , 2013, Molecular endocrinology.

[17]  L. Bonewald,et al.  Isolation and culture of primary osteocytes from the long bones of skeletally mature and aged mice. , 2012, BioTechniques.

[18]  A. Bartke,et al.  GH and IGF1: roles in energy metabolism of long-living GH mutant mice. , 2012, The journals of gerontology. Series A, Biological sciences and medical sciences.

[19]  H. Brown-Borg,et al.  Expression of oxidative phosphorylation components in mitochondria of long-living Ames dwarf mice , 2012, AGE.

[20]  L. Bonewald,et al.  Cell line IDG‐SW3 replicates osteoblast‐to‐late‐osteocyte differentiation in vitro and accelerates bone formation in vivo , 2011, Journal of bone and mineral research : the official journal of the American Society for Bone and Mineral Research.

[21]  A. Lewiński,et al.  Expression of key regulators of mitochondrial biogenesis in growth hormone receptor knockout (GHRKO) mice is enhanced but is not further improved by other potential life-extending interventions. , 2011, The journals of gerontology. Series A, Biological sciences and medical sciences.

[22]  A. Bartke,et al.  Key regulators of mitochondrial biogenesis are increased in kidneys of growth hormone receptor knockout (GHRKO) mice , 2011, Cell biochemistry and function.

[23]  Ralph Müller,et al.  Guidelines for assessment of bone microstructure in rodents using micro–computed tomography , 2010, Journal of bone and mineral research : the official journal of the American Society for Bone and Mineral Research.

[24]  P. Pinton,et al.  Oxidative stress-dependent p66Shc phosphorylation in skin fibroblasts of children with mitochondrial disorders. , 2010, Biochimica et biophysica acta.

[25]  Hughes Jm,et al.  Biological underpinnings of Frost's mechanostat thresholds: the important role of osteocytes. , 2010 .

[26]  K. Jepsen,et al.  Osteocyte apoptosis and control of bone resorption following ovariectomy in mice. , 2010, Bone.

[27]  D. Leroith,et al.  High-Efficient FLPo Deleter Mice in C57BL/6J Background , 2009, PloS one.

[28]  A. Bartke,et al.  Alterations in oxygen consumption, respiratory quotient, and heat production in long-lived GHRKO and Ames dwarf mice, and short-lived bGH transgenic mice. , 2009, The journals of gerontology. Series A, Biological sciences and medical sciences.

[29]  A. Bartke,et al.  Long-living growth hormone receptor knockout mice: Potential mechanisms of altered stress resistance , 2009, Experimental Gerontology.

[30]  R. Seeley,et al.  Effect of growth hormone on susceptibility to diet-induced obesity. , 2006, Endocrinology.

[31]  A. Bartke,et al.  Long-lived growth hormone receptor knockout mice show a delay in age-related changes of body composition and bone characteristics. , 2006, The journals of gerontology. Series A, Biological sciences and medical sciences.

[32]  A. Angelini,et al.  Skeletal muscle fibres synthesis in heart failure: role of PGC-1alpha, calcineurin and GH. , 2005, International journal of cardiology.

[33]  H. Brown-Borg,et al.  Glutathione metabolism in long-living Ames dwarf mice , 2005, Experimental Gerontology.

[34]  Mark A Sussman,et al.  Cardiac Stem Cell and Myocyte Aging, Heart Failure, and Insulin-Like Growth Factor-1 Overexpression , 2004, Circulation research.

[35]  D. Yellon,et al.  New directions for protecting the heart against ischaemia-reperfusion injury: targeting the Reperfusion Injury Salvage Kinase (RISK)-pathway. , 2004, Cardiovascular research.

[36]  C. Tamm,et al.  Signalling pathways for insulin‐like growth factor type 1‐mediated expression of uncoupling protein 3 , 2003, Journal of neurochemistry.

[37]  Arlan Richardson,et al.  Genetic mouse models of extended lifespan , 2003, Experimental Gerontology.

[38]  D. Dorscheid,et al.  Insulin-like growth factor-1 protects ischemic murine myocardium from ischemia/reperfusion associated injury , 2003, Critical care.

[39]  J. Turrens,et al.  Mitochondrial formation of reactive oxygen species , 2003, The Journal of physiology.

[40]  F. Gage,et al.  Retrograde Viral Delivery of IGF-1 Prolongs Survival in a Mouse ALS Model , 2003, Science.

[41]  K. Fukunaga,et al.  Akt is a molecular target for signal transduction therapy in brain ischemic insult. , 2003, Journal of pharmacological sciences.

[42]  Linda Partridge,et al.  Mechanisms of aging: public or private? , 2002, Nature Reviews Genetics.

[43]  Abraham Weizman,et al.  Protective effect of insulin-like-growth-factor-1 against dopamine-induced neurotoxicity in human and rodent neuronal cultures: possible implications for Parkinson’s disease , 2001, Neuroscience Letters.

[44]  A. Bartke,et al.  Reduced Levels of Thyroid Hormones, Insulin, and Glucose, and Lower Body Core Temperature in the Growth Hormone Receptor/Binding Protein Knockout Mouse , 2001, Experimental biology and medicine.

[45]  P. Anversa,et al.  IGF-1 overexpression inhibits the development of diabetic cardiomyopathy and angiotensin II-mediated oxidative stress. , 2001, Diabetes.

[46]  K. Webster,et al.  Reperfusion-Activated Akt Kinase Prevents Apoptosis in Transgenic Mouse Hearts Overexpressing Insulin-Like Growth Factor-1 , 2001, Circulation research.

[47]  L. Guarente,et al.  Genetic pathways that regulate ageing in model organisms , 2000, Nature.

[48]  J R Mosley,et al.  Osteoporosis and bone functional adaptation: mechanobiological regulation of bone architecture in growing and adult bone, a review. , 2000, Journal of rehabilitation research and development.

[49]  K. Sjögren,et al.  Disproportional skeletal growth and markedly decreased bone mineral content in growth hormone receptor -/- mice. , 2000, Biochemical and biophysical research communications.

[50]  A. Windebank,et al.  Neurons Undergo Apoptosis in Animal and Cell Culture Models of Diabetes , 1999, Neurobiology of Disease.

[51]  Y Honda,et al.  The daf‐2 gene network for longevity regulates oxidative stress resistance and Mn‐superoxide dismutase gene expression in Caenorhabditis elegans , 1999, FASEB journal : official publication of the Federation of American Societies for Experimental Biology.

[52]  F. Lezoualc’h,et al.  Insulin-like Growth Factor-1-mediated Neuroprotection against Oxidative Stress Is Associated with Activation of Nuclear Factor κB* , 1999, The Journal of Biological Chemistry.

[53]  D. Kiel,et al.  Association between insulin-like growth factor I and bone mineral density in older women and men: the Framingham Heart Study. , 1998, The Journal of clinical endocrinology and metabolism.

[54]  M. Brooke,et al.  Neurotrophic factors decrease the release of creatine kinase and prostaglandin E2 from metabolically stressed muscle , 1998, Neuromuscular Disorders.

[55]  V. Skulachev,et al.  High protonic potential actuates a mechanism of production of reactive oxygen species in mitochondria , 1997, FEBS letters.

[56]  G. Lithgow Invertebrate gerontology: The age mutations of Caenorhabditis elegans , 1996, BioEssays : news and reviews in molecular, cellular and developmental biology.

[57]  S. Austad,et al.  Genetic analysis of ageing: role of oxidative damage and environmental stresses , 1996, Nature Genetics.

[58]  R. Marcus,et al.  Effects of recombinant insulin‐like growth factor‐I and growth hormone on bone turnover in elderly women , 1995, Journal of bone and mineral research : the official journal of the American Society for Bone and Mineral Research.

[59]  S. Melov,et al.  Thermotolerance and extended life-span conferred by single-gene mutations and induced by thermal stress. , 1995, Proceedings of the National Academy of Sciences of the United States of America.

[60]  P. L. Larsen Aging and resistance to oxidative damage in Caenorhabditis elegans. , 1993, Proceedings of the National Academy of Sciences of the United States of America.

[61]  J. Vanfleteren Oxidative stress and ageing in Caenorhabditis elegans. , 1993, The Biochemical journal.

[62]  D. Harman Free radical theory of aging. , 1992, Triangle; the Sandoz journal of medical science.

[63]  P. Gluckman,et al.  A role for IGF-1 in the rescue of CNS neurons following hypoxic-ischemic injury. , 1992, Biochemical and biophysical research communications.

[64]  V. Weissig,et al.  Mitochondrial medicine. Preface. , 2015, Methods in molecular biology.

[65]  V. Weissig,et al.  Mitochondrial Medicine , 2015, Methods in Molecular Biology.

[66]  M. Petit,et al.  Biological underpinnings of Frost's mechanostat thresholds: the important role of osteocytes. , 2010, Journal of musculoskeletal & neuronal interactions.

[67]  A. Bartke,et al.  How diet interacts with longevity genes , 2008 .

[68]  M. C. Savanelli,et al.  Somatopause: dismetabolic and bone effects. , 2005, Journal of endocrinological investigation.

[69]  Andrzej Bartke,et al.  Life extension in the dwarf mouse. , 2004, Current topics in developmental biology.

[70]  Linda Partridge,et al.  Mechanisms of ageing: public or private? , 2002, Nature reviews. Genetics.

[71]  P. Douglas,et al.  Importance of an intact growth hormone/insulin-like growth factor 1 axis for normal post-infarction healing: studies in dwarf rats. , 2001, Endocrinology.