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Li Z, Bagchi DP, Zhu J, Bowers E, Yu H, Hardij J, Mori H, Granger K, Skjaerlund J, Mandair G, Abrishami S, Singer K, Hankenson KD, Rosen CJ, MacDougald OA. Constitutive bone marrow adipocytes suppress local bone formation. JCI Insight 2022; 7:160915. [PMID: 36048537 PMCID: PMC9675472 DOI: 10.1172/jci.insight.160915] [Citation(s) in RCA: 23] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2022] [Accepted: 08/31/2022] [Indexed: 12/15/2022] Open
Abstract
BM adipocytes (BMAd) are a unique cell population derived from BM mesenchymal progenitors and marrow adipogenic lineage precursors. Although they have long been considered to be a space filler within bone cavities, recent studies have revealed important physiological roles in hematopoiesis and bone metabolism. To date, the approaches used to study BMAd function have been confounded by contributions by nonmarrow adipocytes or by BM stromal cells. To address this gap in the field, we have developed a BMAd-specific Cre mouse model to deplete BMAds by expression of diphtheria toxin A (DTA) or by deletion of peroxisome proliferator-activated receptor gamma (Pparg). We found that DTA-induced loss of BMAds results in decreased hematopoietic stem and progenitor cell numbers and increased bone mass in BMAd-enriched locations, including the distal tibiae and caudal vertebrae. Elevated bone mass appears to be secondary to enhanced endosteal bone formation, suggesting a local effect caused by depletion of BMAd. Augmented bone formation with BMAd depletion protects mice from bone loss induced by caloric restriction or ovariectomy, and it facilitates the bone-healing process after fracture. Finally, ablation of Pparg also reduces BMAd numbers and largely recapitulates high-bone mass phenotypes observed with DTA-induced BMAd depletion.
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Affiliation(s)
- Ziru Li
- Department of Molecular & Integrative Physiology and
| | | | - Junxiong Zhu
- Department of Orthopedic Surgery, University of Michigan Medical School, Ann Arbor, Michigan, USA
- Department of Orthopedic Surgery, The Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | - Emily Bowers
- Department of Pediatrics, University of Michigan Medical School, Ann Arbor, Michigan, USA
| | - Hui Yu
- Department of Molecular & Integrative Physiology and
| | - Julie Hardij
- Department of Molecular & Integrative Physiology and
| | - Hiroyuki Mori
- Department of Molecular & Integrative Physiology and
| | | | - Jon Skjaerlund
- Department of Orthopedic Surgery, University of Michigan Medical School, Ann Arbor, Michigan, USA
| | - Gurjit Mandair
- Department of Biologic and Materials Sciences, School of Dentistry, University of Michigan, Ann Arbor, Michigan, USA
| | - Simin Abrishami
- Department of Pediatrics, University of Michigan Medical School, Ann Arbor, Michigan, USA
| | - Kanakadurga Singer
- Department of Molecular & Integrative Physiology and
- Department of Pediatrics, University of Michigan Medical School, Ann Arbor, Michigan, USA
| | - Kurt D. Hankenson
- Department of Orthopedic Surgery, University of Michigan Medical School, Ann Arbor, Michigan, USA
| | | | - Ormond A. MacDougald
- Department of Molecular & Integrative Physiology and
- Department of Internal Medicine, University of Michigan Medical School, Ann Arbor, Michigan, USA
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Bredella MA, Fazeli PK, Bourassa J, Rosen CJ, Bouxsein ML, Klibanski A, Miller KK. The effect of short-term high-caloric feeding and fasting on bone microarchitecture. Bone 2022; 154:116214. [PMID: 34571202 PMCID: PMC8671292 DOI: 10.1016/j.bone.2021.116214] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/02/2021] [Revised: 09/15/2021] [Accepted: 09/20/2021] [Indexed: 01/03/2023]
Abstract
BACKGROUND States of chronic overnutrition and undernutrition are both associated with impaired bone health and increased fracture risk but there are no data on bone microarchitecture following short-term controlled nutritional challenges. OBJECTIVE The purpose of our study was to evaluate the impact of short-term high-caloric feeding and fasting on bone microarchitecture. We hypothesized that both high-caloric feeding and fasting would have negative effects on microarchitecture. MATERIALS AND METHODS We recruited 23 adult healthy subjects (13 males, 10 females, mean age 33.2 ± 1.4 years, mean BMI 26.0 ± 1.5 kg/m2). Subjects underwent an in-patient 10-day high-caloric visit (caloric intake with goal to achieve 7% weight gain), after which they went home to resume a normal diet for 13-18 days (stabilization period), and were then readmitted for a 10-day in-patient fasting stay (no caloric intake). All subjects underwent HRpQCT (XtremeCT, Scanco Medical AG, Brüttisellen, Switzerland) of the distal tibia and distal radius after each visit to assess volumetric bone mineral density (vBMD), trabecular and cortical microarchitecture, and strength estimates. The Wilcoxon signed rank test was used to perform within group comparisons. RESULTS During the high-caloric period, there was a mean increase in weight by 6.3 + 1.7% (p < 0.0001). There were no significant changes in bone parameters in the distal tibia or distal radius (p > 0.05). During the stabilization period there was a significant reduction in weight by -2.7 + 1.9% (p < 0.0001) but no change in bone parameters (p > 0.05). During the fasting period there was a further reduction in weight by -8.8 + 1.2% (p < 0.0001). In the distal tibia, there was a significant increase in total and cortical vBMD, trabecular and cortical parameters as well as strength estimates (p < 0.05). In the distal radius there was an increase in total and trabecular vBMD (p < 0.05), while there were no changes in other microarchitecture parameters or strengths estimates. CONCLUSION Short-term fasting after high-caloric feeding improves vBMD, bone microarchitecture and strength estimates of the distal tibia, while short-term high-caloric feeding does not change vBMD or microarchitecture. These results suggest that short-term fasting after high-caloric feeding in healthy individuals improves bone health and that these changes can be detected using HRpQCT in-vivo.
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Affiliation(s)
- Miriam A Bredella
- Division of Musculoskeletal Imaging and Intervention, Department of Radiology, Massachusetts General Hospital and Harvard Medical School, Boston, MA 02114, United States of America.
| | - Pouneh K Fazeli
- Neuroendocrine Unit, Massachusetts General Hospital and Harvard Medical School, Boston, MA 02114, United States of America
| | - Jenna Bourassa
- Neuroendocrine Unit, Massachusetts General Hospital and Harvard Medical School, Boston, MA 02114, United States of America
| | - Clifford J Rosen
- Maine Medical Center Research Institute, Scarborough, ME, United States of America
| | - Mary L Bouxsein
- Department of Orthopedic Surgery, Massachusetts General Hospital and Harvard Medical School, Boston, MA 02114, United States of America
| | - Anne Klibanski
- Neuroendocrine Unit, Massachusetts General Hospital and Harvard Medical School, Boston, MA 02114, United States of America
| | - Karen K Miller
- Neuroendocrine Unit, Massachusetts General Hospital and Harvard Medical School, Boston, MA 02114, United States of America
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Brent MB. A review of the skeletal effects of exposure to high altitude and potential mechanisms for hypobaric hypoxia-induced bone loss. Bone 2022; 154:116258. [PMID: 34781048 DOI: 10.1016/j.bone.2021.116258] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/26/2021] [Revised: 11/08/2021] [Accepted: 11/09/2021] [Indexed: 12/20/2022]
Abstract
Mountaineering and exposure to high altitude result in physiological adaptations to the reduced inspiratory oxygen availability. Acute mountain sickness (AMS), high altitude pulmonary edema (HAPE), and high altitude cerebral edema (HACE) are well-described harmful effects of exposure to high altitude. Common to AMS, HAPE, and HACE are distinct clinical signs and symptoms of impaired function. However, several studies have suggested that high altitude might result in a substantial bone loss, which usually does not produce any apparent symptoms. This review aims to provide a comprehensive overview of, and map current knowledge of the skeletal effects of hypobaric hypoxia and high altitude. PubMed and Embase were searched from inception to September 6, 2021, to identify studies investigating the skeletal effects of exposure to hypobaric hypoxia and high altitude. Three hundred sixty titles and abstracts were screened, and 20 full-text articles were included (16 in vivo studies and four real-world human studies). In rodents, simulated high altitude up to 2900 m did not result in any adverse skeletal effects. In contrast, studies exposing animals to very high altitude (3500-5500 m) reported substantial reductions in BMD, cortical morphology, and bone strength, as well as deteriorated trabecular microstructure. Detrimental microstructural effects were also reported in rats exposed to simulated extreme altitude (6000 m). Finally, real-world human studies in mountaineers suggested high altitude exposure reduced bone mineral density (BMD) and that the harmful skeletal effects of hypobaric hypoxia were not entirely recovered after 12 months. In conclusion, in vivo and real-world studies demonstrated high altitude exposure results in adverse skeletal effects. The underlying mechanism for hypobaric hypoxia-induced bone loss is not elucidated.
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Affiliation(s)
- Mikkel Bo Brent
- Department of Biomedicine, Aarhus University, Aarhus, Denmark.
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Li Z, MacDougald OA. Preclinical models for investigating how bone marrow adipocytes influence bone and hematopoietic cellularity. Best Pract Res Clin Endocrinol Metab 2021; 35:101547. [PMID: 34016532 PMCID: PMC8458229 DOI: 10.1016/j.beem.2021.101547] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Laboratory mice are a crucial preclinical model system for investigating bone marrow adipocyte (BMAd)-bone and BMAd-hematopoiesis interactions. In this review, we evaluate the suitability of mice to model common human diseases related to osteopenia or hematopoietic disorders, point out consistencies and discrepancies among different studies, and provide insights into model selection. Species, age, sex, skeletal site, and treatment protocol should all be considered when designing future studies.
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Affiliation(s)
- Ziru Li
- Department of Molecular & Integrative Physiology, University of Michigan Medical School, Ann Arbor, MI, USA
| | - Ormond A MacDougald
- Department of Molecular & Integrative Physiology, University of Michigan Medical School, Ann Arbor, MI, USA; Department of Internal Medicine, University of Michigan Medical School, Ann Arbor, MI, USA.
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5
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Jensen VFH, Mølck AM, Dalgaard M, McGuigan FE, Akesson KE. Changes in bone mass associated with obesity and weight loss in humans: Applicability of animal models. Bone 2021; 145:115781. [PMID: 33285255 DOI: 10.1016/j.bone.2020.115781] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/22/2020] [Revised: 11/05/2020] [Accepted: 11/27/2020] [Indexed: 12/21/2022]
Abstract
The implications of obesity and weight loss for human bone health are not well understood. Although the bone changes associated with weight loss are similar in humans and rodents, that is not the case for obesity. In humans, obesity is generally associated with increased bone mass, an outcome which is exacerbated by advanced age and menopause. In rodents, by contrast, bone mass decreases in proportion to severity and duration of obesity, and is influenced by sex, age and mechanical load. Despite these discrepancies, rodents are frequently used to model the situation in humans. In this review, we summarise the existing knowledge of the effects of obesity and weight loss on bone mass in humans and rodents, focusing on the translatability of findings from animal models. We then describe how animal models should be used to broaden the understanding of the relationship between obesity, weight loss, and skeletal health in humans. Specifically, we highlight the aspects of study design that should be considered to optimise translatability of the rodent models of obesity and weight loss. Notably, the sex, age, and nutritional status of the animals should ideally match those of interest in humans. With these caveats in mind, and depending on the research question asked, our review underscores that animal models can provide valuable information for obesity and weight-management research.
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Affiliation(s)
- Vivi F H Jensen
- Lund University, Department of Clinical Sciences Malmö and Skåne University Hospital, Department of Orthopedics, Inga Marie Nilssons Gata 22, 205 02 Malmö, Sweden.
| | - Anne-Marie Mølck
- Novo Nordisk A/S, Department of Safety Sciences, Imaging & Data Management, Novo Nordisk Park 1, 2760 Maaloev, Denmark
| | - Majken Dalgaard
- Novo Nordisk A/S, Department of Safety Sciences, Imaging & Data Management, Novo Nordisk Park 1, 2760 Maaloev, Denmark
| | - Fiona E McGuigan
- Lund University, Department of Clinical Sciences Malmö and Skåne University Hospital, Department of Orthopedics, Inga Marie Nilssons Gata 22, 205 02 Malmö, Sweden
| | - Kristina E Akesson
- Lund University, Department of Clinical Sciences Malmö and Skåne University Hospital, Department of Orthopedics, Inga Marie Nilssons Gata 22, 205 02 Malmö, Sweden
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Zhou Y, Deng T, Zhang H, Guan Q, Zhao H, Yu C, Shao S, Zhao M, Xu J. Hypercholesterolaemia increases the risk of high‑turnover osteoporosis in men. Mol Med Rep 2019; 19:4603-4612. [PMID: 30957178 PMCID: PMC6522796 DOI: 10.3892/mmr.2019.10131] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2018] [Accepted: 03/08/2019] [Indexed: 01/23/2023] Open
Abstract
As the incidence of osteoporosis (OP) and hypercholesterolaemia in men has increased, male OP has drawn more attention from clinicians worldwide. The present study sought to investigate the effects of cholesterol on male bone. Between July 2015 and October 2015, 216 men (aged ≥18 years) were recruited for this cross‑sectional study. To test our clinical hypothesis, we designed two male animal models: Exogenous hypercholesterolaemia induced by a high‑cholesterol diet (HCD) and endogenous hypercholesterolaemia induced by apolipoprotein E (ApoE) knockout. Finally, the direct effects of cholesterol on osteoblasts were observed in cell experiments. In our clinical studies, men with hypercholesterolaemia displayed a lower bone mineral density (BMD) and increased beta collagen cross‑linking (beta‑CTX) and type I anterior collagen amino terminal peptide (PINP) levels compared to those of the control subjects. Serum cholesterol levels were a significant independent predictor of BMD, beta‑CTX and PINP and were negatively correlated with BMD and positively correlated with beta‑CTX and PINP levels. Our animal experimental results validated our clinical results, as they also indicated that hypercholesterolaemia damages bone microstructure and reduces bone strength. Cholesterol directly increased osteoblast functional gene expression in vitro. Hypercholesterolaemia increases the risk of high‑turnover osteoporosis in men at least in part by excessively promoting the activity of the remodelling pathway. In addition, hypercholesterolaemia damages the bone microstructure, resulting in osteopenia or OP and reduced bone strength, leading to a higher risk of fracture in men. We emphasize the importance of preventing and treating hypercholesterolaemia as well as monitoring bone metabolic markers and BMD in men with hypercholesterolemia for the effective prevention of bone loss and subsequent fracture. In addition, our findings provide a theoretical basis for the development of treatments for high cholesterol‑induced osteoporosis in men.
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Affiliation(s)
- Yanman Zhou
- Department of Endocrinology, Shandong Provincial Hospital Affiliated to Shandong University, Jinan, Shandong 250021, P.R. China
| | - Tuo Deng
- Department of Endocrinology, Shandong Provincial Hospital Affiliated to Shandong University, Jinan, Shandong 250021, P.R. China
| | - Haiqing Zhang
- Department of Endocrinology, Shandong Provincial Hospital Affiliated to Shandong University, Jinan, Shandong 250021, P.R. China
| | - Qingbo Guan
- Department of Endocrinology, Shandong Provincial Hospital Affiliated to Shandong University, Jinan, Shandong 250021, P.R. China
| | - Hongqiang Zhao
- Department of Internal Medicine, Laiwu People's Hospital, Laiwu, Shandong 271100, P.R. China
| | - Chunxiao Yu
- Department of Endocrinology, Shandong Provincial Hospital Affiliated to Shandong University, Jinan, Shandong 250021, P.R. China
| | - Shanshan Shao
- Department of Endocrinology, Shandong Provincial Hospital Affiliated to Shandong University, Jinan, Shandong 250021, P.R. China
| | - Meng Zhao
- Department of Endocrinology, Shandong Provincial Hospital Affiliated to Shandong University, Jinan, Shandong 250021, P.R. China
| | - Jin Xu
- Department of Endocrinology, Shandong Provincial Hospital Affiliated to Shandong University, Jinan, Shandong 250021, P.R. China
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7
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Farr JN, Almeida M. The Spectrum of Fundamental Basic Science Discoveries Contributing to Organismal Aging. J Bone Miner Res 2018; 33:1568-1584. [PMID: 30075061 PMCID: PMC6327947 DOI: 10.1002/jbmr.3564] [Citation(s) in RCA: 43] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/15/2018] [Revised: 07/25/2018] [Accepted: 07/27/2018] [Indexed: 12/22/2022]
Abstract
Aging research has undergone unprecedented advances at an accelerating rate in recent years, leading to excitement in the field as well as opportunities for imagination and innovation. Novel insights indicate that, rather than resulting from a preprogrammed series of events, the aging process is predominantly driven by fundamental non-adaptive mechanisms that are interconnected, linked, and overlap. To varying degrees, these mechanisms also manifest with aging in bone where they cause skeletal fragility. Because these mechanisms of aging can be manipulated, it might be possible to slow, delay, or alleviate multiple age-related diseases and their complications by targeting conserved genetic signaling pathways, controlled functional networks, and basic biochemical processes. Indeed, findings in various mammalian species suggest that targeting fundamental aging mechanisms (eg, via either loss-of-function or gain-of-function mutations or administration of pharmacological therapies) can extend healthspan; ie, the healthy period of life free of chronic diseases. In this review, we summarize the evidence supporting the role of the spectrum of fundamental basic science discoveries contributing to organismal aging, with emphasis on mammalian studies and in particular aging mechanisms in bone that drive skeletal fragility. These mechanisms or aging hallmarks include: genomic instability, telomere attrition, epigenetic alterations, loss of proteostasis, deregulated nutrient sensing, mitochondrial dysfunction, cellular senescence, stem cell exhaustion, and altered intercellular communication. Because these mechanisms are linked, interventions that ameliorate one hallmark can in theory ameliorate others. In the field of bone and mineral research, current challenges include defining the relative contributions of each aging hallmark to the natural skeletal aging process, better understanding the complex interconnections among the hallmarks, and identifying the most effective therapeutic strategies to safely target multiple hallmarks. Based on their interconnections, it may be feasible to simultaneously interfere with several fundamental aging mechanisms to alleviate a wide spectrum of age-related chronic diseases, including osteoporosis. © 2018 American Society for Bone and Mineral Research.
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Affiliation(s)
- Joshua N Farr
- Division of Endocrinology and Metabolism and Kogod Center on Aging, Mayo Clinic, Rochester, MN, USA
| | - Maria Almeida
- Division of Endocrinology and Metabolism, Center for Osteoporosis and Metabolic Bone Diseases, University of Arkansas for Medical Sciences, Little Rock, AR, USA
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8
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Baek K, Kang J, Lee J, Kim M, Baek JH. The Time Point-Specific Effect of Beta-Adrenergic Blockade in Attenuating High Fat Diet-Induced Obesity and Bone Loss. Calcif Tissue Int 2018; 103:217-226. [PMID: 29460182 DOI: 10.1007/s00223-018-0407-3] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/21/2017] [Accepted: 02/14/2018] [Indexed: 12/22/2022]
Abstract
We aimed to clarify the key factor determining the effect of beta blocker attenuating high fat diet- induced obesity and bone loss. Six-week-old C57BL/6 male mice were assigned to groups reflecting different relative onset of obesity and beta blocker administration, different diet (control vs. high fat), and treatment (vehicle vs. beta blocker: propranolol). Mice in Group 1 were fed a control diet (CON) or high fat diet (HIGH) with vehicle or propranolol for 12 weeks. Mice in Group 2 were fed a CON or HIGH without pharmaceutical treatment for the first 12 weeks, followed by another 12 weeks of treatment with vehicle or propranolol. Mice in Group 3 were fed a CON without pharmaceutical treatment for the first 12 weeks, followed by stratification into diet-based subgroups and another 12 weeks of treatment with vehicle or propranolol. Propranolol attenuated the HIGH-induced increase in body weight/fat mass in Group 1 mice and in Group 3 mice, but not in Group 2 mice. Propranolol mitigated HIGH-induced reduction in femoral trabecular bone mineral density and bone architecture deterioration in Group 1 mice but not in Group 2 mice. HIGH feeding in Group 3 did not compromise skeletal integrity. Taken together, propranolol attenuates HIGH-induced body weight increases while weight gain is in progress but not once obesity has already been established. HIGH feeding during the growth period results in compromised bone mass/architecture; which can be attenuated by propranolol administration during the growth period, but not by propranolol administration after obesity has already been established.
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Affiliation(s)
- Kyunghwa Baek
- Department of Pharmacology, College of Dentistry and Research Institute of Oral Science, Gangneung-Wonju National University, Gangwondo, 210-702, Republic of Korea
| | - Jiho Kang
- Department of Molecular Genetics, School of Dentistry and Dental Research Institute, Seoul National University, Seoul, 08826, Republic of Korea
| | - Jinu Lee
- Department of Molecular Genetics, School of Dentistry and Dental Research Institute, Seoul National University, Seoul, 08826, Republic of Korea
| | - Min Kim
- Department of Pharmacology, College of Dentistry and Research Institute of Oral Science, Gangneung-Wonju National University, Gangwondo, 210-702, Republic of Korea
| | - Jeong-Hwa Baek
- Department of Molecular Genetics, School of Dentistry and Dental Research Institute, Seoul National University, Seoul, 08826, Republic of Korea.
- Department of Molecular Genetics, School of Dentistry and Dental Research Institute, Seoul National University, Seoul, 110-749, Republic of Korea.
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9
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Takeno A, Kanazawa I, Notsu M, Tanaka KI, Sugimoto T. Glucose uptake inhibition decreases expressions of receptor activator of nuclear factor-kappa B ligand (RANKL) and osteocalcin in osteocytic MLO-Y4-A2 cells. Am J Physiol Endocrinol Metab 2018; 314:E115-E123. [PMID: 29018002 DOI: 10.1152/ajpendo.00159.2017] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Bone and glucose metabolism are closely associated with each other. Both osteoblast and osteoclast functions are important for the action of osteocalcin, which plays pivotal roles as an endocrine hormone regulating glucose metabolism. However, it is unknown whether osteocytes are involved in the interaction between bone and glucose metabolism. We used MLO-Y4-A2, a murine long bone-derived osteocytic cell line, to investigate effects of glucose uptake inhibition on expressions of osteocalcin and bone-remodeling modulators in osteocytes. We found that glucose transporter 1 (GLUT1) is expressed in MLO-Y4-A2 cells and that treatment with phloretin, a GLUT inhibitor, significantly inhibited glucose uptake. Real-time PCR and Western blot showed that phloretin significantly and dose-dependently decreased the expressions of RANKL and osteocalcin, whereas osteoprotegerin or sclerostin was not affected. Moreover, phloretin activated AMP-activated protein kinase (AMPK), an intracellular energy sensor. Coincubation of ara-A, an AMPK inhibitor, with phloretin canceled the phloretin-induced decrease in osteocalcin expression, but not RANKL. In contrast, phloretin suppressed phosphorylation of ERK1/2, JNK, and p38 MAPK, and treatments with the p38 inhibitor SB203580 and the MEK inhibitor PD98059, but not the JNK inhibitor SP600125, significantly decreased expressions of RANKL and osteocalcin. These results indicate that glucose uptake by GLUT1 is required for RANKL and osteocalcin expressions in osteocytes, and that inhibition of glucose uptake decreases their expressions through AMPK, ERK1/2, and p38 MAPK pathways. These findings suggest that lowering glucose uptake into osteocytes may contribute to maintain blood glucose levels by decreasing osteocalcin expression and RANKL-induced bone resorption.
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Affiliation(s)
- Ayumu Takeno
- Internal Medicine 1, Shimane University Faculty of Medicine, Izumo, Shimane , Japan
| | - Ippei Kanazawa
- Internal Medicine 1, Shimane University Faculty of Medicine, Izumo, Shimane , Japan
| | - Masakazu Notsu
- Internal Medicine 1, Shimane University Faculty of Medicine, Izumo, Shimane , Japan
| | - Ken-Ichiro Tanaka
- Internal Medicine 1, Shimane University Faculty of Medicine, Izumo, Shimane , Japan
| | - Toshitsugu Sugimoto
- Internal Medicine 1, Shimane University Faculty of Medicine, Izumo, Shimane , Japan
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10
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Most J, Tosti V, Redman LM, Fontana L. Calorie restriction in humans: An update. Ageing Res Rev 2017; 39:36-45. [PMID: 27544442 PMCID: PMC5315691 DOI: 10.1016/j.arr.2016.08.005] [Citation(s) in RCA: 297] [Impact Index Per Article: 42.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2016] [Revised: 08/11/2016] [Accepted: 08/11/2016] [Indexed: 12/11/2022]
Abstract
Calorie restriction (CR), a nutritional intervention of reduced energy intake but with adequate nutrition, has been shown to extend healthspan and lifespan in rodent and primate models. Accumulating data from observational and randomized clinical trials indicate that CR in humans results in some of the same metabolic and molecular adaptations that have been shown to improve health and retard the accumulation of molecular damage in animal models of longevity. In particular, moderate CR in humans ameliorates multiple metabolic and hormonal factors that are implicated in the pathogenesis of type 2 diabetes, cardiovascular diseases, and cancer, the leading causes of morbidity, disability and mortality. In this paper, we will discuss the effects of CR in non-obese humans on these physiological parameters. Special emphasis is committed to recent clinical intervention trials that have investigated the feasibility and effects of CR in young and middle-aged men and women on parameters of energy metabolism and metabolic risk factors of age-associated disease in great detail. Additionally, data from individuals who are either naturally exposed to CR or those who are self-practicing this dietary intervention allows us to speculate on longer-term effects of more severe CR in humans.
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Affiliation(s)
- Jasper Most
- Reproductive Endocrinology and Women's Health, Pennington Biomedical Research Center, Louisiana State University, Baton Rouge, LA 70808, USA
| | - Valeria Tosti
- Division of Geriatrics and Nutritional Science, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Leanne M Redman
- Reproductive Endocrinology and Women's Health, Pennington Biomedical Research Center, Louisiana State University, Baton Rouge, LA 70808, USA.
| | - Luigi Fontana
- Division of Geriatrics and Nutritional Science, Washington University School of Medicine, St. Louis, MO 63110, USA; Department of Clinical and Experimental Sciences, Brescia University Medical School, Brescia, Italy; CEINGE Biotecnologie Avanzate, Napoli, Italy.
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11
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Zainabadi K, Liu CJ, Caldwell ALM, Guarente L. SIRT1 is a positive regulator of in vivo bone mass and a therapeutic target for osteoporosis. PLoS One 2017; 12:e0185236. [PMID: 28937996 PMCID: PMC5609767 DOI: 10.1371/journal.pone.0185236] [Citation(s) in RCA: 75] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2017] [Accepted: 09/09/2017] [Indexed: 01/07/2023] Open
Abstract
Overexpression or pharmacological activation of SIRT1 has been shown to extend the lifespan of mice and protect against aging-related diseases. Here we show that pharmacological activation of SIRT1 protects in two models of osteoporosis. Ovariectomized female mice and aged male mice, models for post-menopausal and aging-related osteoporosis, respectively, show significant improvements in bone mass upon treatment with SIRT1 agonist, SRT1720. Further, we find that calorie restriction (CR) results in a two-fold upregulation of sirt1 mRNA expression in bone tissue that is associated with increased bone mass in CR mice. Reciprocally, SIRT1 whole-body knockout (KO) mice, as well as osteoblast and osteoclast specific KOs, show a low bone mass phenotype; though double knockout mice (containing SIRT1 deleted in both osteoblasts and osteoclasts) do not show a more severe phenotype. Altogether, these findings provide strong evidence that SIRT1 is a positive regulator of bone mass and a promising target for the development of novel therapeutics for osteoporosis.
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Affiliation(s)
- Kayvan Zainabadi
- Glenn Center for the Science of Aging, Department of Biology, Koch Institute, MIT, Cambridge, Massachusetts, United States of America
- * E-mail:
| | - Cassie J. Liu
- Glenn Center for the Science of Aging, Department of Biology, Koch Institute, MIT, Cambridge, Massachusetts, United States of America
| | - Alison L. M. Caldwell
- Glenn Center for the Science of Aging, Department of Biology, Koch Institute, MIT, Cambridge, Massachusetts, United States of America
| | - Leonard Guarente
- Glenn Center for the Science of Aging, Department of Biology, Koch Institute, MIT, Cambridge, Massachusetts, United States of America
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12
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Protein/amino-acid modulation of bone cell function. BONEKEY REPORTS 2016; 5:827. [PMID: 28149508 PMCID: PMC5238414 DOI: 10.1038/bonekey.2016.58] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/16/2015] [Accepted: 06/24/2016] [Indexed: 01/07/2023]
Abstract
Nutrients (protein, carbohydrates and fats) have traditionally been thought of as fuels simply providing the energy for cellular metabolic activity. According to the classic view, if nutrients are available, then anabolic pathways are activated, and if nutrients are not available, catabolic pathways are activated. However, it is becoming increasingly clear that nutrient effects on bone cells (stem cells, osteoblasts and osteoclasts) are complex, some nutrients promote bone formation, whereas others interfere with bone formation or actually promote bone break down. At an organ level, nutrient intake can suppress bone breakdown and modulate the activity of the calcium/vitamin D/parathyroid hormone axis. At a cellular level, nutrient intake can impact cellular energetics either through a direct mechanism (binding or uptake of the nutrient into the cell) or indirect (by elevating nutrient-related hormones such as insulin, insulin-like growth factor 1 or incretin hormones). It is also becoming clear that within a nutrient class (for example, protein), individual components (that is, amino acids) can have markedly different effects on cell function and impact bone formation. The focus of this review will be on one nutrient class in particular, dietary protein. As the prevalence of inadequate dietary protein intake increases with age, these findings may have translational implications as to the optimal dietary protein content in the setting of age-associated bone loss.
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13
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Hughes JM, Popp KL, Yanovich R, Bouxsein ML, Matheny RW. The role of adaptive bone formation in the etiology of stress fracture. Exp Biol Med (Maywood) 2016; 242:897-906. [PMID: 27496801 DOI: 10.1177/1535370216661646] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Stress fractures are common injuries with load-bearing activities. Stress fractures have been reported in the scientific literature for over a century; however, the etiology continues to be investigated with important distinctions made between the contributions of the tissue-level processes of bone remodeling and modeling. In response to novel repetitive loading, increased bone remodeling may serve to replace fatigue-damaged bone while at the same time creating temporary porosity. Much attention has been given to the role of remodeling in the etiology of stress fracture; however, the role of bone modeling has received less attention. Modest increases in modeling, via bone formation on the periosteal surface of long bones in response to mechanical loading, greatly increases the fatigue resistance of bone. Thus, enhancing this adaptive bone formation is a promising target for stress fracture prevention, and a focus on adaptive bone formation may reveal novel risk factors for stress fracture.
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Affiliation(s)
- Julie M Hughes
- 1 Military Performance Division, United States Army Research Institute of Environmental Medicine, Natick, MA 01760, USA
| | - Kristin L Popp
- 2 Endocrine Unit, Massachusetts General Hospital, Boston, MA 02114, USA
| | - Ran Yanovich
- 3 The Warrior Health Research Institute of Military Physiology, Israel Defense Forces' Medical Corps.,4 Heller Institute of Medical Research, Sheba Medical Center, Tel-Hashomer 52621, Israel
| | - Mary L Bouxsein
- 2 Endocrine Unit, Massachusetts General Hospital, Boston, MA 02114, USA.,5 Center for Advanced Orthopedic Studies, Beth Israel Deaconess Medical Center, Boston, MA 02215, USA.,6 Department of Orthopaedic Surgery, Harvard Medical School, Boston, MA 02215, USA
| | - Ronald W Matheny
- 1 Military Performance Division, United States Army Research Institute of Environmental Medicine, Natick, MA 01760, USA
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14
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Devlin MJ, Brooks DJ, Conlon C, Vliet MV, Louis L, Rosen CJ, Bouxsein ML. Daily leptin blunts marrow fat but does not impact bone mass in calorie-restricted mice. J Endocrinol 2016; 229:295-306. [PMID: 27340200 PMCID: PMC5171226 DOI: 10.1530/joe-15-0473] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/05/2016] [Accepted: 04/11/2016] [Indexed: 01/02/2023]
Abstract
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<0.05 for all). Most significantly, although MAT was elevated in CR vs N overall, leptin treatment blunted MAT formation in CR mice by 50% vs VEH (P<0.05 for both leptin doses). CR LEP2 mice weighed less vs CR VEH mice at 9-10 weeks of age (P<0.05), but leptin treatment did not affect body fat percentage, BMD, or bone microarchitecture within either diet. These data demonstrate that once daily leptin bolus during CR inhibits bone marrow adipose expansion without affecting bone mass acquisition, suggesting that leptin has distinct effects on starvation-induced bone marrow fat formation and skeletal acquisition.
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Affiliation(s)
- M J Devlin
- Department of AnthropologyUniversity of Michigan, Ann Arbor, Michigan, USA
| | - D J Brooks
- Center for Advanced Orthopedic StudiesBeth Israel Deaconess Medical Center, Boston, Massachusetts, USA
| | - C Conlon
- Center for Advanced Orthopedic StudiesBeth Israel Deaconess Medical Center, Boston, Massachusetts, USA
| | - M van Vliet
- Center for Advanced Orthopedic StudiesBeth Israel Deaconess Medical Center, Boston, Massachusetts, USA
| | - L Louis
- Center for Advanced Orthopedic StudiesBeth Israel Deaconess Medical Center, Boston, Massachusetts, USA
| | - C J Rosen
- Maine Medical Center Research InstituteScarborough, Maine, USA
| | - M L Bouxsein
- Center for Advanced Orthopedic StudiesBeth Israel Deaconess Medical Center, Boston, Massachusetts, USA Harvard Medical SchoolBoston, Massachusetts, USA
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15
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Stringhetta-Garcia CT, Singulani MP, Santos LF, Louzada MJQ, Nakamune ACS, Chaves-Neto AH, Rossi AC, Ervolino E, Dornelles RCM. The effects of strength training and raloxifene on bone health in aging ovariectomized rats. Bone 2016; 85:45-54. [PMID: 26812611 DOI: 10.1016/j.bone.2015.11.023] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/14/2015] [Revised: 11/09/2015] [Accepted: 11/28/2015] [Indexed: 11/23/2022]
Abstract
The aim of this study was to investigate the effects of strength training (ST) and raloxifene (Ral), alone or in combination, on the prevention of bone loss in an aging estrogen-deficient rat model. Aging Wistar female rats were ovariectomized at 14months and allocated to four groups: (1) non-trained and treated with vehicle, NT-Veh; (2) strength training and treated with vehicle, ST-Veh; (3) non-trained and treated with raloxifene, NT-Ral; and (4) strength training and treated with raloxifene, ST-Ral. ST was performed on a ladder three times per week and Ral was administered daily by gavage (1mg/kg/day), both for 120days. Areal bone mineral density (aBMD), strength, microarchitecture, and biomarkers (osteocalcin, OCN; osteoprotegerin, OPG; and tartrate-resistant acid phosphatase, TRAP) were assessed. Immunohistochemistry was performed for runt-related transcription factor 2 (RUNX2), osterix (OSX), OCN, OPG, TRAP, and receptor activator of nuclear factor kappa-B ligand (RANKL). The rats that performed ST (ST-Veh) or were treated with Ral (NT-Ral) showed significant improvements in aBMD (p=0.001 and 0.004), bone strength (p=0.001), and bone microarchitecture, such as BV/TV (%) (p=0.001), BS/TV (mm(2)/mm(3)) (p=0.023 and 0.002), Conn.Dn (1/mm(3)) (p=0.001), Tb.N (1/mm) (p=0.012 and 0.011), Tb.Th (1/mm) (p=0.001), SMI (p=0.001 and 0.002), Tb.Sp (p=0.001), and DA (p=0.002 and 0.007); there was also a significant decrease in plasma levels of OCN (p=0.001 and 0.002) and OPG (p=0.003 and 0.014), compared with animals in the NT-Veh group. Ral, with or without ST, promoted an increased immunolabeling pattern for RUNX2 (p=0.0105 and p=0.0006) and OSX (p=0.0105), but a reduced immunolabeling pattern for TRAP (p=0.0056) and RANKL (p=0.033 and 0.004). ST increased the immunolabeling pattern for RUNX2 (p=0.0105), and association with Ral resulted in an increased immunolabeling pattern for OPG (p=0.0034) and OCN (p=0.0024). In summary, ST and Ral administration in aged, estrogen-deficient Wistar female rats is associated with a decrease in bone turnover marker plasma levels, increased activity of cells that promote osteoblastogenesis, and decreased activity of cells that promote osteoclastogenesis; these are correlated with higher aBMD, bone strength, and bone microarchitecture at the femoral neck. The results indicate that strength training and Ral are potential tools to reduce the risk of fractures at clinically relevant sites.
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Affiliation(s)
| | | | | | - Mário Jefferson Quirino Louzada
- Programa Multicêntrico de Pós-Graduação em Ciências Fisiológicas; Faculdade de Medicina Veterinária de Araçatuba, UNESP - Univ Estadual Paulista, Campus de Araçatuba, Departamento de Apoio, Produção e Saúde Animal
| | - Ana Cláudia Stevanato Nakamune
- Programa Multicêntrico de Pós-Graduação em Ciências Fisiológicas; Faculdade de Odontologia de Araçatuba, UNESP - Univ Estadual Paulista, Campus de Araçatuba, Departamento de Ciências Básicas
| | - Antonio Hernandes Chaves-Neto
- Faculdade de Odontologia de Araçatuba, UNESP - Univ Estadual Paulista, Campus de Araçatuba, Departamento de Ciências Básicas
| | - Ana Cláudia Rossi
- Faculdade de Odontologia de Piracicaba, UNICAMP - Univ de Campinas, Campus de Piracicaba, Departamento de Morfologia
| | - Edilson Ervolino
- Faculdade de Odontologia de Araçatuba, UNESP - Univ Estadual Paulista, Campus de Araçatuba, Departamento de Ciências Básicas
| | - Rita Cássia Menegati Dornelles
- Programa Multicêntrico de Pós-Graduação em Ciências Fisiológicas; Faculdade de Odontologia de Araçatuba, UNESP - Univ Estadual Paulista, Campus de Araçatuba, Departamento de Ciências Básicas
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16
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Behrendt AK, Kuhla A, Osterberg A, Polley C, Herlyn P, Fischer DC, Scotland M, Wree A, Histing T, Menger MD, Müller-Hilke B, Mittlmeier T, Vollmar B. Dietary Restriction-Induced Alterations in Bone Phenotype: Effects of Lifelong Versus Short-Term Caloric Restriction on Femoral and Vertebral Bone in C57BL/6 Mice. J Bone Miner Res 2016; 31:852-63. [PMID: 26572927 DOI: 10.1002/jbmr.2745] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/01/2015] [Revised: 11/11/2015] [Accepted: 11/13/2015] [Indexed: 12/17/2022]
Abstract
Caloric restriction (CR) is a well-described dietary intervention that delays the onset of aging-associated biochemical and physiological changes, thereby extending the life span of rodents. The influence of CR on metabolism, strength, and morphology of bone has been controversially discussed in literature. Thus, the present study evaluated whether lifelong CR versus short-term late-onset dietary intervention differentially affects the development of senile osteoporosis in C57BL/6 mice. Two different dietary regimens with 40% food restriction were performed: lifelong CR starting in 4-week-old mice was maintained for 4, 20, or 74 weeks. In contrast, short-term late-onset CR lasting a period of 12 weeks was commenced at 48 or 68 weeks of age. Control mice were fed ad libitum (AL). Bone specimens were assessed using microcomputed tomography (μCT, femur and lumbar vertebral body) and biomechanical testing (femur). Adverse effects of CR, including reduced cortical bone mineral density (Ct.BMD) and thickness (Ct.Th), were detected to some extent in senile mice (68+12w) but in particular in cortical bone of young growing mice (4+4w), associated with reduced femoral failure force (F). However, we observed a profound capacity of bone to compensate these deleterious changes of minor nutrition with increasing age presumably via reorganization of trabecular bone. Especially in lumbar vertebrae, lifelong CR lasting 20 or 74 weeks had beneficial effects on trabecular bone mineral density (Tb.BMD), bone volume fraction (BV/TV), and trabecular number (Tb.N). In parallel, lifelong CR groups showed reduced structure model index values compared to age-matched controls indicating a transformation of vertebral trabecular bone microarchitecture toward a platelike geometry. This effect was not visible in senile mice after short-term 12-week CR. In summary, CR has differential effects on cortical and trabecular bone dependent on bone localization and starting age. Our study underlines that bone compartments possess a lifelong capability to cope with changing nutritional influences.
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Affiliation(s)
- Ann-Kathrin Behrendt
- Department of Trauma, Hand, and Reconstructive Surgery, Rostock University Medical Center, Rostock, Germany.,Institute for Experimental Surgery, Rostock University Medical Center, Rostock, Germany
| | - Angela Kuhla
- Institute for Experimental Surgery, Rostock University Medical Center, Rostock, Germany
| | - Anja Osterberg
- Institute of Immunology, Rostock University Medical Center, Rostock, Germany
| | - Christian Polley
- Institute for Experimental Surgery, Rostock University Medical Center, Rostock, Germany
| | - Philipp Herlyn
- Department of Trauma, Hand, and Reconstructive Surgery, Rostock University Medical Center, Rostock, Germany
| | | | - Maike Scotland
- Department of Trauma, Hand, and Reconstructive Surgery, Rostock University Medical Center, Rostock, Germany
| | - Andreas Wree
- Institute of Anatomy, Rostock University Medical Center, Rostock, Germany
| | - Tina Histing
- Department of Trauma, Hand, and Reconstructive Surgery, University of Saarland, Homburg/Saar, Germany
| | - Michael D Menger
- Institute for Clinical and Experimental Surgery, University of Saarland, Homburg/Saar, Germany
| | | | - Thomas Mittlmeier
- Department of Trauma, Hand, and Reconstructive Surgery, Rostock University Medical Center, Rostock, Germany
| | - Brigitte Vollmar
- Institute for Experimental Surgery, Rostock University Medical Center, Rostock, Germany
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17
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Green tea supplementation benefits body composition and improves bone properties in obese female rats fed with high-fat diet and caloric restricted diet. Nutr Res 2015; 35:1095-105. [PMID: 26525915 DOI: 10.1016/j.nutres.2015.09.014] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2015] [Revised: 09/18/2015] [Accepted: 09/21/2015] [Indexed: 12/15/2022]
Abstract
This study investigated the effects of green tea polyphenols (GTP) supplementation on body composition, bone properties, and serum markers in obese rats fed a high-fat diet (HFD) or a caloric restricted diet (CRD). Forty-eight female rats were fed an HFD ad libitum for 4 months, and then either continued on the HFD or the CRD with or without 0.5% GTP in water. Body composition, bone efficacy, and serum markers were measured. We hypothesized that GTP supplementation would improve body composition, mitigate bone loss, and restore bone microstructure in obese animals fed either HFD or CRD. CRD lowered percent fat mass; bone mass and trabecular number of tibia, femur and lumbar vertebrae; femoral strength; trabecular and cortical thickness of tibia; insulin-like growth factor-I and leptin. CRD also increased percent fat-free mass; trabecular separation of tibia and femur; eroded surface of tibia; bone formation rate and erosion rate at tibia shaft; and adiponectin. GTP supplementation increased femoral mass and strength (P = .026), trabecular thickness (P = .012) and number (P = .019), and cortical thickness of tibia (P < .001), and decreased trabecular separation (P = .021), formation rate (P < .001), and eroded surface (P < .001) at proximal tibia, and insulin-like growth factor-I and leptin. There were significant interactions (diet type × GTP) on osteoblast surface/bone surface, mineral apposition rate at periosteal and endocortical bones, periosteal bone formation rate, and trabecular thickness at femur and lumbar vertebrate (P < .05). This study demonstrates that GTP supplementation for 4 months benefited body composition and improved bone microstructure and strength in obese rats fed with HFD or HFD followed by CRD diet.
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18
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Hinton PS, Shankar K, Eaton LM, Rector RS. Obesity-related changes in bone structural and material properties in hyperphagic OLETF rats and protection by voluntary wheel running. Metabolism 2015; 64:905-16. [PMID: 25963848 DOI: 10.1016/j.metabol.2015.04.004] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/12/2014] [Revised: 03/25/2015] [Accepted: 04/24/2015] [Indexed: 12/11/2022]
Abstract
PURPOSE To examine how the development of obesity and the associated insulin resistance affect bone structural and material properties, and bone formation and resorption markers in the Otsuka Long-Evans Tokushima Fatty (OLETF) rat model. METHODS This was a 36-week study of sedentary, hyperphagic, male OLETF rats (OLETF-SED), exercise-treated OLETF rats (OLETF-EX) and sedentary non-hyperphagic controls (LETO-SED) with data collection at 13, 20, and 40 weeks of age (n = 5-8 animals per group per timepoint). RESULTS Body mass and fat (%) were significantly greater in OLETF-SED versus controls. OLETF-SED were insulin resistant at 13 and 20 weeks, with overt diabetes by 40 weeks. At 13weeks, OLETF-SED had lower total body BMC and BMD and serum P1NP compared with LETO-SED. Differences in total body BMC and BMD between OLETF-SED and LETO-SED persisted at 20 weeks, with reductions in total and cortical BMD of the tibia. OLETF-SED also had lesser femur diameter, cross-sectional area, polar moment of area, and torque at fracture than LETO-SED. By 40 weeks, OLETF-SED had elevated bone resorption and reduced intrinsic bone strength. OLETF-EX did not show the excessive weight gain, obesity, insulin resistance or diabetes observed in OLETF-SED. OLETF-EX had greater BMD than OLETF-SED, and structural and material properties of the femur were significantly increased in OLETF-EX relative to OLETF-SED and LETO-SED. CONCLUSIONS The negative skeletal effects of excessive adiposity and insulin resistance were evident early in the progressive obesity with lasting negative impacts on intrinsic and extrinsic bone strength. Exercise protected against obesity-associated skeletal changes with marked benefits on the biomechanical properties of bone.
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Affiliation(s)
- Pamela S Hinton
- Department of Nutrition and Exercise Physiology, University of Missouri-Columbia, Columbia, MO, USA.
| | - Kartik Shankar
- Department of Pediatrics, University of Arkansas for Medical Sciences, Little Rock, Arkansas, USA, Arkansas Children's Nutrition Center, Little Rock, AR, USA
| | - Lynn M Eaton
- Department of Nutrition and Exercise Physiology, University of Missouri-Columbia, Columbia, MO, USA
| | - R Scott Rector
- Research Service-Harry S Truman Memorial Veterans Medical Center, and Departments of Medicine-Division of Gastroenterology and Hepatology and Nutrition and Exercise Physiology, University of Missouri-Columbia, Columbia, MO, USA
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19
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Baek K, Park HJ, Hwang HR, Baek JH. Propranolol attenuates calorie restriction- and high calorie diet-induced bone marrow adiposity. BMB Rep 2015; 47:587-92. [PMID: 25248563 PMCID: PMC4261518 DOI: 10.5483/bmbrep.2014.47.10.176] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2014] [Indexed: 12/29/2022] Open
Abstract
We investigated the effects of β-adrenergic activation on bone marrow adiposity and on adipogenic differentiation of bone marrow mesenchymal stem cells (BMSCs). C57BL/6 mice were subjected to a control (CON), high calorie (HIGH) or low calorie (LOW) diet for 12 weeks. In each group, mice were treated with vehicle (VEH) or propranolol. The number of adipocytes per area bone marrow was increased in LOWVEH and HIGHVEH mice compared with CONVEH mice, which was attenuated by propranolol. Isoproterenol increased lipid droplet accumulation and adipogenic marker gene expression in 3T3-L1 preadipocytes and mouse BMSCs, which were blocked by propranolol. Conditioned medium obtained from MC3T3-E1 osteoblasts suppressed adipogenic differentiation of 3T3-L1 cells, which was significantly attenuated by treatment of MC3T3-E1 cells with isoproterenol. These data suggest that β-adrenergic activation enhances bone marrow adipogenesis via direct stimulation of BMSCs adipogenesis and indirect inhibition of osteoblast anti-adipogenic potential.
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Affiliation(s)
- Kyunghwa Baek
- Department of Pharmacology and Research Institute of Oral Science, College of Dentistry, Gangneung-Wonju National University, Gangwon 210-702, Korea
| | - Hyun-Jung Park
- Department of Molecular Genetics, School of Dentistry and Dental Research Institute, Seoul National University, Seoul 110-744, Korea
| | - Hyo Rin Hwang
- Department of Molecular Genetics, School of Dentistry and Dental Research Institute, Seoul National University, Seoul 110-744, Korea
| | - Jeong-Hwa Baek
- Department of Molecular Genetics, School of Dentistry and Dental Research Institute, Seoul National University, Seoul 110-744, Korea
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20
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Baek K, Hwang HR, Park HJ, Kwon A, Qadir AS, Baek JH. Propranolol, a β-adrenergic antagonist, attenuates the decrease in trabecular bone mass in high calorie diet fed growing mice. BMB Rep 2015; 47:506-11. [PMID: 24393528 PMCID: PMC4206726 DOI: 10.5483/bmbrep.2014.47.9.265] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2013] [Indexed: 11/20/2022] Open
Abstract
We investigated the effects of high calorie and low calorie diets on skeletal integrity, and whether β-adrenergic blockade (BB) attenuates bone loss induced by dietary calorie alteration. Male 6-week-old C57BL/6 mice were assigned to either an ad-lib fed control diet (CON), a high calorie diet (HIGH), or a low calorie diet (LOW) group. In each diet group, mice were treated with either vehicle (VEH) or propranolol, a β-adrenergic antagonist. Over 12-weeks, β-blockade mitigated body weight and fat mass increases induced by the high calorie diet. Femoral trabecular bone mineral density and the expression levels of osteogenic marker genes in bone marrow cells were reduced in HIGHVEH and LOWVEH mice, and BB significantly attenuated this decline only in HIGH mice. In summary, the magnitude of bone loss induced by low calorie diet was greater than that caused by high calorie diet in growing mice, and β-blockade mitigated high calorie diet-induced bone loss. [BMB Reports 2014; 47(9): 506-511]
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Affiliation(s)
- Kyunghwa Baek
- Department of Molecular Genetics, School of Dentistry and Dental Research Institute, Seoul National University, Seoul 110-749; Department of Pharmacology and Research Institute of Oral Science, College of Dentistry, Gangneung-Wonju National University, Wonju 210-702, Korea
| | - Hyo Rin Hwang
- Department of Molecular Genetics, School of Dentistry and Dental Research Institute, Seoul National University, Seoul 110-749, Korea
| | - Hyun-Jung Park
- Department of Molecular Genetics, School of Dentistry and Dental Research Institute, Seoul National University, Seoul 110-749, Korea
| | - Arang Kwon
- Department of Molecular Genetics, School of Dentistry and Dental Research Institute, Seoul National University, Seoul 110-749, Korea
| | - Abdul S Qadir
- Department of Molecular Genetics, School of Dentistry and Dental Research Institute, Seoul National University, Seoul 110-749, Korea
| | - Jeong-Hwa Baek
- Department of Molecular Genetics, School of Dentistry and Dental Research Institute, Seoul National University, Seoul 110-749, Korea
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21
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Méquinion M, Chauveau C, Viltart O. The use of animal models to decipher physiological and neurobiological alterations of anorexia nervosa patients. Front Endocrinol (Lausanne) 2015; 6:68. [PMID: 26042085 PMCID: PMC4436882 DOI: 10.3389/fendo.2015.00068] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/12/2015] [Accepted: 04/15/2015] [Indexed: 12/18/2022] Open
Abstract
Extensive studies were performed to decipher the mechanisms regulating feeding due to the worldwide obesity pandemy and its complications. The data obtained might be adapted to another disorder related to alteration of food intake, the restrictive anorexia nervosa. This multifactorial disease with a complex and unknown etiology is considered as an awful eating disorder since the chronic refusal to eat leads to severe, and sometimes, irreversible complications for the whole organism, until death. There is an urgent need to better understand the different aspects of the disease to develop novel approaches complementary to the usual psychological therapies. For this purpose, the use of pertinent animal models becomes a necessity. We present here the various rodent models described in the literature that might be used to dissect central and peripheral mechanisms involved in the adaptation to deficient energy supplies and/or the maintenance of physiological alterations on the long term. Data obtained from the spontaneous or engineered genetic models permit to better apprehend the implication of one signaling system (hormone, neuropeptide, neurotransmitter) in the development of several symptoms observed in anorexia nervosa. As example, mutations in the ghrelin, serotonin, dopamine pathways lead to alterations that mimic the phenotype, but compensatory mechanisms often occur rendering necessary the use of more selective gene strategies. Until now, environmental animal models based on one or several inducing factors like diet restriction, stress, or physical activity mimicked more extensively central and peripheral alterations decribed in anorexia nervosa. They bring significant data on feeding behavior, energy expenditure, and central circuit alterations. Animal models are described and criticized on the basis of the criteria of validity for anorexia nervosa.
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Affiliation(s)
- Mathieu Méquinion
- INSERM UMR-S1172, Development and Plasticity of Postnatal Brain, Lille, France
| | - Christophe Chauveau
- Pathophysiology of Inflammatory Bone Diseases, EA 4490, University of the Littoral Opal Coast, Boulogne sur Mer, France
| | - Odile Viltart
- INSERM UMR-S1172, Early stages of Parkinson diseases, University Lille 1, Lille, France
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22
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Abstract
Obesity and osteoporosis are two of the most common chronic disorders of the 21st century. Both are accompanied by significant morbidity. The only place in the mammalian organism where bone and fat lie adjacent to each other is in the bone marrow. Marrow adipose tissue is a dynamic depot that probably exists as both constitutive and regulated compartments. Adipocytes secrete cytokines and adipokines that either stimulate or inhibit adjacent osteoblasts. The relationship of marrow adipose tissue to other fat depots is complex and might play very distinct parts in modulation of metabolic homoeostasis, haemopoiesis, and osteogenesis. Understanding of the relationship between bone and fat cells that arise from the same progenitor within the bone marrow niche provides insight into the pathophysiology of age-related osteoporosis, diabetes, and obesity.
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Affiliation(s)
| | - Clifford J Rosen
- Maine Medical Center Research Institute, Scarborough, ME 04074, USA
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23
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Méquinion M, Caron E, Zgheib S, Stievenard A, Zizzari P, Tolle V, Cortet B, Lucas S, Prévot V, Chauveau C, Viltart O. Physical activity: benefit or weakness in metabolic adaptations in a mouse model of chronic food restriction? Am J Physiol Endocrinol Metab 2015; 308:E241-55. [PMID: 25465889 DOI: 10.1152/ajpendo.00340.2014] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
In restrictive-type anorexia nervosa (AN) patients, physical activity is usually associated with food restriction, but its physiological consequences remain poorly characterized. In female mice, we evaluated the impact of voluntary physical activity with/without chronic food restriction on metabolic and endocrine parameters that might contribute to AN. In this protocol, FRW mice (i.e., food restriction with running wheel) reached a crucial point of body weight loss (especially fat mass) faster than FR mice (i.e., food restriction only). However, in contrast to FR mice, their body weight stabilized, demonstrating a protective effect of a moderate, regular physical activity. Exercise delayed meal initiation and duration. FRW mice displayed food anticipatory activity compared with FR mice, which was strongly diminished with the prolongation of the protocol. The long-term nature of the protocol enabled assessment of bone parameters similar to those observed in AN patients. Both restricted groups adapted their energy metabolism differentially in the short and long term, with less fat oxidation in FRW mice and a preferential use of glucose to compensate for the chronic energy imbalance. Finally, like restrictive AN patients, FRW mice exhibited low leptin levels, high plasma concentrations of corticosterone and ghrelin, and a disruption of the estrous cycle. In conclusion, our model suggests that physical activity has beneficial effects on the adaptation to the severe condition of food restriction despite the absence of any protective effect on lean and bone mass.
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Affiliation(s)
- Mathieu Méquinion
- University Lille (ULCO, USTL, Lille2), Lille, France; Development and Plasticity of Postnatal Brain, UMR 837 Institut National de la Sante et de la Recherche Medicale (INSERM), Lille, France; Physiopathology of Inflammatory Bone diseases, EA4490, Boulogne sur Mer, France
| | - Emilie Caron
- Development and Plasticity of Postnatal Brain, UMR 837 Institut National de la Sante et de la Recherche Medicale (INSERM), Lille, France
| | - Sara Zgheib
- University Lille (ULCO, USTL, Lille2), Lille, France; Physiopathology of Inflammatory Bone diseases, EA4490, Boulogne sur Mer, France
| | - Aliçia Stievenard
- University Lille (ULCO, USTL, Lille2), Lille, France; Molecular Events Associated With Early stages of Parkinson's Disease UMR 837 INSERM, Lille, France
| | - Philippe Zizzari
- Psychiatry and Neurosciences Center, UMR 894 INSERM, Paris, France; and
| | - Virginie Tolle
- Psychiatry and Neurosciences Center, UMR 894 INSERM, Paris, France; and
| | - Bernard Cortet
- University Lille (ULCO, USTL, Lille2), Lille, France; Department of Rheumatology, Centre Hospitalier Universitaire Régional, Lille, France
| | - Stéphanie Lucas
- University Lille (ULCO, USTL, Lille2), Lille, France; Physiopathology of Inflammatory Bone diseases, EA4490, Boulogne sur Mer, France
| | - Vincent Prévot
- University Lille (ULCO, USTL, Lille2), Lille, France; Development and Plasticity of Postnatal Brain, UMR 837 Institut National de la Sante et de la Recherche Medicale (INSERM), Lille, France
| | - Christophe Chauveau
- University Lille (ULCO, USTL, Lille2), Lille, France; Physiopathology of Inflammatory Bone diseases, EA4490, Boulogne sur Mer, France
| | - Odile Viltart
- University Lille (ULCO, USTL, Lille2), Lille, France; Development and Plasticity of Postnatal Brain, UMR 837 Institut National de la Sante et de la Recherche Medicale (INSERM), Lille, France;
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Forrester SJ, Kawata K, Lee H, Kim JS, Sebzda K, Butler T, Yingling VR, Park JY. Bioinformatic identification of connective tissue growth factor as an osteogenic protein within skeletal muscle. Physiol Rep 2014; 2:2/12/e12255. [PMID: 25539834 PMCID: PMC4332228 DOI: 10.14814/phy2.12255] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Aging is associated with increasing incidence of osteoporosis; a skeletal disorder characterized by compromised bone strength that may predispose patients to an increased risk of fracture. It is imperative to identify novel ways in which to attenuate such declines in the functional properties of bone. The purpose of this study was to identify, through in silico, in vitro, and in vivo approaches, a protein secreted from skeletal muscle that is putatively involved in bone formation. We performed a functional annotation bioinformatic analysis of human skeletal muscle‐derived secretomes (n = 319) using DAVID software. Cross‐referencing was conducted using OMIM, Unigene, UniProt, GEO, and CGAP databases. Signal peptides and transmembrane residues were analyzed using SignalP and TMHMM software. To further investigate functionality of the identified protein, L6 and C2C12 myotubes were grown for in vitro analysis. C2C12 myotubes were subjected to 16 h of glucose deprivation (GD) prior to analysis. In vivo experiments included analysis of 6‐week calorie restricted (CR) rat muscle samples. Bioinformatic analysis yielded 15 genes of interest. GEO dataset analysis identified BMP5, COL1A2, CTGF, MGP, MMP2, and SPARC as potential targets for further processing. Following TMHMM and SignalP processing, CTGF was chosen as a candidate gene. CTGF expression level was increased during L6 myoblast differentiation (P <0.01). C2C12 myotubes showed no change in response to GD. Rat soleus muscle samples exhibited an increase in CTGF expression (n = 16) in response to CR (35%) (P <0.05). CTGF was identified as a skeletal muscle expressed protein through bioinformatic analysis of skeletal muscle‐derived secretomes and in vitro/in vivo analysis. Future study is needed to determine the role of muscle‐derived CTGF in bone formation and remodeling processes. In this study, we explore the method of bioinformatic analysis, coupled with in vitro and in vivo investigation, to identify a new skeletal muscle‐derived protein with osteogenic properties. CTGF is expressed in young, healthy skeletal muscle, and this expression is increased with calorie restriction. Muscular secretion of CTGF might play an osteogenic role in maintaining bone health.
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Affiliation(s)
- Steven J Forrester
- Cardiovascular Genomics Laboratory, Department of Kinesiology, College of Public Health, Temple University, Philadelphia, Pennsylvania
| | - Keisuke Kawata
- Cardiovascular Genomics Laboratory, Department of Kinesiology, College of Public Health, Temple University, Philadelphia, Pennsylvania
| | - Hojun Lee
- Cardiovascular Genomics Laboratory, Department of Kinesiology, College of Public Health, Temple University, Philadelphia, Pennsylvania
| | - Ji-Seok Kim
- Cardiovascular Genomics Laboratory, Department of Kinesiology, College of Public Health, Temple University, Philadelphia, Pennsylvania
| | - Kelly Sebzda
- Cardiovascular Genomics Laboratory, Department of Kinesiology, College of Public Health, Temple University, Philadelphia, Pennsylvania
| | - Tiffiny Butler
- Cardiovascular Genomics Laboratory, Department of Kinesiology, College of Public Health, Temple University, Philadelphia, Pennsylvania
| | - Vanessa R Yingling
- Department of Kinesiology, California State University, East BayHayward, California
| | - Joon-Young Park
- Cardiovascular Genomics Laboratory, Department of Kinesiology, College of Public Health, Temple University, Philadelphia, Pennsylvania Cardiovascular Research Center, School of Medicine, Temple UniversityPhiladelphia, Pennsylvania
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Hattori S, Park JH, Agata U, Oda M, Higano M, Aikawa Y, Akimoto T, Nabekura Y, Yamato H, Ezawa I, Omi N. Food restriction causes low bone strength and microarchitectural deterioration in exercised growing male rats. J Nutr Sci Vitaminol (Tokyo) 2014; 60:35-42. [PMID: 24759258 DOI: 10.3177/jnsv.60.35] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
The pathogenesis of bone disorders in young male athletes has not been well understood. We hypothesized that bone fragility is caused by low energy availability, due to insufficient food intake and excessive exercise energy expenditure in young male athletes. To examine this hypothesis, we investigated the influence of food restriction on bone strength and bone morphology in exercised growing male rats, using three-point bending test, dual-energy X-ray absormetry, and micro-computed tomography. Four-week-old male Sprague-Dawley rats were divided randomly into the following groups: the control (Con) group, exercise (Ex) group, food restriction (R) group, and food restriction plus exercise (REx) group after a 1-wk acclimatization period. Thirty-percent food restriction in the R and REx groups was carried out in comparison with that in the Con group. Voluntary running exercise was performed in the Ex and REx groups. The experimental period lasted 13 wk. At the endpoint of this experiment, the bone strength of the femurs and tibial BMD in the REx group were significantly lower than those in the Con group. Moreover, trabecular bone volume and cortical bone volume in the REx group were also significantly lower than those in the Con group. These findings indicate that food restriction causes low bone strength and microarchitectural deterioration in exercised growing male rats.
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Robertson KL, Rowland NE, Krigbaum J. Effects of caloric restriction on nitrogen and carbon stable isotope ratios in adult rat bone. RAPID COMMUNICATIONS IN MASS SPECTROMETRY : RCM 2014; 28:2065-2074. [PMID: 25156596 DOI: 10.1002/rcm.6994] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/23/2014] [Revised: 07/21/2014] [Accepted: 07/22/2014] [Indexed: 06/03/2023]
Abstract
RATIONALE Stable isotope analysis is a valuable technique for dietary estimation in ecological and archaeological research, yet many variables can potentially affect tissue stable isotope signatures. Controlled feeding studies across a range of species have consistently demonstrated impacts of caloric restriction on tissue stable isotope ratios, but most have focused on juvenile, fasting, and/or starving individuals, and most have utilized soft tissues despite the importance of bone for paleodietary analyses. The goal of this study was to determine whether temporally defined, moderate food restriction could affect stable carbon and/or nitrogen isotope ratios in adult mammalian bone - a tissue that arguably reflects long-term dietary signals. METHODS Adult rats fed a standard laboratory diet were restricted to 45% of ad libitum intakes for 3 or 6 months. Relevant anatomical and physiological parameters were measured to confirm that the restriction protocol resulted in significant nutritional stress and to provide independent data to facilitate interpretation of stable isotope ratios. Femoral bone δ(13)Ccollagen, δ(15)Ncollagen, and δ(13)Capatite values were determined by isotope ratio mass spectrometry. RESULTS Calorie-restricted animals exhibited a small, yet significant enrichment in (15)Ncollagen compared with control animals, reflecting protein-calorie stress. While the δ(13)Ccollagen values did not differ, the δ(13)Capatite values revealed less enrichment in (13)C than in controls, reflecting catabolism of body fat. Independent anatomical and physiological data from these same individuals support these interpretations. CONCLUSIONS Results indicate that moderate caloric restriction does not appreciably undermine broad interpretations of dietary signals in adult mammalian bone. Significant variability among individuals or groups, however, is best explained by marked differences in energy intake over variable timescales. An inverse relationship between the δ(13)Capatite and δ(15)Ncollagen values observed in this study indicates that a more robust pattern is expected with more severe or prolonged restriction and suggests this pattern may have utility as a marker of food deprivation in archaeological populations.
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Affiliation(s)
- Kimberly L Robertson
- Department of Anthropology, Box 117305, University of Florida, Gainesville, FL, 32611, USA; Department of Psychology, Box 112250, University of Florida, Gainesville, FL, 32611, USA
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Zgheib S, Méquinion M, Lucas S, Leterme D, Ghali O, Tolle V, Zizzari P, Bellefontaine N, Legroux-Gérot I, Hardouin P, Broux O, Viltart O, Chauveau C. Long-term physiological alterations and recovery in a mouse model of separation associated with time-restricted feeding: a tool to study anorexia nervosa related consequences. PLoS One 2014; 9:e103775. [PMID: 25090643 PMCID: PMC4121212 DOI: 10.1371/journal.pone.0103775] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2014] [Accepted: 07/02/2014] [Indexed: 12/15/2022] Open
Abstract
Background Anorexia nervosa is a primary psychiatric disorder, with non-negligible rates of mortality and morbidity. Some of the related alterations could participate in a vicious cycle limiting the recovery. Animal models mimicking various physiological alterations related to anorexia nervosa are necessary to provide better strategies of treatment. Aim To explore physiological alterations and recovery in a long-term mouse model mimicking numerous consequences of severe anorexia nervosa. Methods C57Bl/6 female mice were submitted to a separation-based anorexia protocol combining separation and time-restricted feeding for 10 weeks. Thereafter, mice were housed in standard conditions for 10 weeks. Body weight, food intake, body composition, plasma levels of leptin, adiponectin, IGF-1, blood levels of GH, reproductive function and glucose tolerance were followed. Gene expression of several markers of lipid and energy metabolism was assayed in adipose tissues. Results Mimicking what is observed in anorexia nervosa patients, and despite a food intake close to that of control mice, separation-based anorexia mice displayed marked alterations in body weight, fat mass, lean mass, bone mass acquisition, reproductive function, GH/IGF-1 axis, and leptinemia. mRNA levels of markers of lipogenesis, lipolysis, and the brown-like adipocyte lineage in subcutaneous adipose tissue were also changed. All these alterations were corrected during the recovery phase, except for the hypoleptinemia that persisted despite the full recovery of fat mass. Conclusion This study strongly supports the separation-based anorexia protocol as a valuable model of long-term negative energy balance state that closely mimics various symptoms observed in anorexia nervosa, including metabolic adaptations. Interestingly, during a recovery phase, mice showed a high capacity to normalize these parameters with the exception of plasma leptin levels. It will be interesting therefore to explore further the central and peripheral effects of the uncorrected hypoleptinemia during recovery from separation-based anorexia.
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Affiliation(s)
- Sara Zgheib
- Université Lille Nord de France, Boulogne sur Mer, France
- Physiopathologie des Maladies Osseuses Inflammatoires, Boulogne sur Mer, France
| | - Mathieu Méquinion
- Université Lille Nord de France, Boulogne sur Mer, France
- Physiopathologie des Maladies Osseuses Inflammatoires, Boulogne sur Mer, France
- UMR INSERM 837, Développement et Plasticité du Cerveau Post-natal, Lille, France
| | - Stéphanie Lucas
- Université Lille Nord de France, Boulogne sur Mer, France
- Physiopathologie des Maladies Osseuses Inflammatoires, Boulogne sur Mer, France
| | - Damien Leterme
- Université Lille Nord de France, Boulogne sur Mer, France
- Physiopathologie des Maladies Osseuses Inflammatoires, Boulogne sur Mer, France
| | - Olfa Ghali
- Université Lille Nord de France, Boulogne sur Mer, France
- Physiopathologie des Maladies Osseuses Inflammatoires, Boulogne sur Mer, France
| | - Virginie Tolle
- UMR-S 894 INSERM, Centre de Psychiatrie et Neurosciences, Université Paris Descartes, Sorbonne Paris Cité, Paris, France
| | - Philippe Zizzari
- UMR-S 894 INSERM, Centre de Psychiatrie et Neurosciences, Université Paris Descartes, Sorbonne Paris Cité, Paris, France
| | - Nicole Bellefontaine
- Université Lille Nord de France, Boulogne sur Mer, France
- UMR INSERM 837, Développement et Plasticité du Cerveau Post-natal, Lille, France
| | - Isabelle Legroux-Gérot
- Université Lille Nord de France, Boulogne sur Mer, France
- Physiopathologie des Maladies Osseuses Inflammatoires, Boulogne sur Mer, France
- Service de Rhumatologie, Hôpital Roger Salengro, CHU Lille, France
| | - Pierre Hardouin
- Université Lille Nord de France, Boulogne sur Mer, France
- Physiopathologie des Maladies Osseuses Inflammatoires, Boulogne sur Mer, France
| | - Odile Broux
- Université Lille Nord de France, Boulogne sur Mer, France
- Physiopathologie des Maladies Osseuses Inflammatoires, Boulogne sur Mer, France
| | - Odile Viltart
- Université Lille Nord de France, Boulogne sur Mer, France
- UMR INSERM 837, Développement et Plasticité du Cerveau Post-natal, Lille, France
- Université de Lille1, Villeneuve d’Ascq, France
| | - Christophe Chauveau
- Université Lille Nord de France, Boulogne sur Mer, France
- Physiopathologie des Maladies Osseuses Inflammatoires, Boulogne sur Mer, France
- * E-mail:
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Ahn H, Seo DH, Kim HS, Choue R. Calorie restriction aggravated cortical and trabecular bone architecture in ovariectomy-induced estrogen-deficient rats. Nutr Res 2014; 34:707-13. [PMID: 25172380 DOI: 10.1016/j.nutres.2014.07.006] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2014] [Revised: 06/28/2014] [Accepted: 07/04/2014] [Indexed: 10/25/2022]
Abstract
We hypothesized that calorie restriction (CR) and estrogen deficiency (ovariectomy [OVX]) would aggravate bone biomarkers and structural parameters in rats. Seven-week-old female Sprague-Dawley rats were randomized to sham-operated groups and fed either an ad libitum diet (SHAM-AL) or a CR diet (SHAM-CR); ovariectomy-operated groups were fed an ad libitum diet (OVX-AL) or a CR diet (OVX-CR). For 8 weeks, the OVX-AL and SHAM-AL groups were fed the same diet, whereas CR groups were fed a diet containing 50% fewer calories. Bone-related biomarkers and structural parameters (OC; deoxypyridinoline [DPD]; N-terminal telopeptide, NTx; architecture and mineralization; and microcomputed tomography images) were analyzed at the end of the experiment. The serum OC levels of calorie-restricted groups (SHAM-CR and OVX-CR) were significantly lower than those of the AL groups (SHAM-AL and OVX-AL) (P < .05). Urinary DPD levels of calorie-restricted and ovariectomized groups were higher than those of their counterparts (P < .05), whereas urinary NTx levels of calorie-restricted groups were higher than those of AL groups (P < .05). In regard to trabecular bone, the calorie-restricted and ovariectomized groups had lower values of bone volume to total volume, trabecular number, and bone mineral density, but higher values of trabecular separation than those of their counterparts (P < .05). Regarding cortical bone, the calorie-restricted groups had reduced values of bone volume, mean polar moment of inertia, and cortical thickness compared to the AL groups (P < .05). In conclusion, severe CR with or without OVX during the growth period in rats is equally detrimental to bone; CR has detrimental effects on trabecular and cortical bone; and estrogen deficiency only had an effect on trabecular bone.
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Affiliation(s)
- Hyejin Ahn
- Department of Medical Nutrition, Kyung Hee University, Yongin, Korea
| | - Dong-Hyun Seo
- Department of Biomedical Engineering, Yonsei University, Wonju, Korea
| | - Han Sung Kim
- Department of Biomedical Engineering, Yonsei University, Wonju, Korea
| | - Ryowon Choue
- Department of Medical Nutrition, Kyung Hee University, Yongin, Korea; Research Institute of Medical Nutrition, Kyung Hee University, Seoul, Korea.
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Jeon YK, Kim WJ, Shin MJ, Chung HY, Kim SS, Kim BH, Kim SJ, Kim YK, Kim IJ. Short-term caloric restriction does not reduce bone mineral density in rats with early type 2 diabetes. Endocrinol Metab (Seoul) 2014; 29:70-6. [PMID: 24741457 PMCID: PMC3970278 DOI: 10.3803/enm.2014.29.1.70] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/02/2013] [Accepted: 10/11/2013] [Indexed: 01/14/2023] Open
Abstract
BACKGROUND The effect of caloric restriction (CR) in the setting of diabetes on bone metabolism has not yet been fully studied. The aim of this study is to determine if short-term CR alters bone mass and metabolism in Otsuka Long-Evans Tokushima fatty (OLETF) rats, an animal model of type 2 diabetes. METHODS Four groups (n=5) were created: OLETF rats with food ad libitum (AL), OLETF rats with CR, Long-Evans Tokusima Otsuka (LETO) rats with food AL, and LETO rats with CR. The CR condition was imposed on 24-week-old male rats using a 40% calorie reduction for 4 weeks. The effect of CR on femoral bone mineral density (BMD) was assessed by dual-energy X-ray absorptiometry. Serum markers were measured by immunoassay. RESULTS After 4 weeks of CR, body weight decreased in both strains. The BMD decreased in LETO rats and was maintained in OLETF rats. After adjustment for body weight, BMD remained lower in LETO rats (P=0.017) but not OLETF rats (P=0.410). Bone-specific alkaline phosphatase levels decreased in LETO rats (P=0.025) but not in OLEFT rats (P=0.347). Serum leptin levels were reduced after CR in both strains, but hyperleptinemia remained in OLETF rats (P=0.009). CR increased 25-hydroxyvitamin D levels in OLETF rats (P=0.009) but not in LETO rats (P=0.117). Additionally, interleukin-6 and tumor necrosis factor-α levels decreased only in OLETF rats (P=0.009). CONCLUSION Short-term CR and related weight loss were associated with decreases of femoral BMD in LETO rats while BMD was maintained in OLETF rats. Short-term CR may not alter bone mass and metabolism in type 2 diabetic rats.
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Affiliation(s)
- Yun Kyung Jeon
- Department of Internal Medicine, Pusan National University School of Medicine, Busan, Korea
- Medical Research Institute, Pusan National University School of Medicine, Busan, Korea
| | - Won Jin Kim
- Department of Internal Medicine, Pusan National University School of Medicine, Busan, Korea
- Medical Research Institute, Pusan National University School of Medicine, Busan, Korea
| | - Myung Jun Shin
- Medical Research Institute, Pusan National University School of Medicine, Busan, Korea
- Department of Rehabilitation Medicine, Pusan National University School of Medicine, Busan, Korea
| | | | - Sang Soo Kim
- Department of Internal Medicine, Pusan National University School of Medicine, Busan, Korea
- Medical Research Institute, Pusan National University School of Medicine, Busan, Korea
| | - Bo Hyun Kim
- Department of Internal Medicine, Pusan National University School of Medicine, Busan, Korea
- Medical Research Institute, Pusan National University School of Medicine, Busan, Korea
| | - Seong-Jang Kim
- Department of Nuclear Medicine, Pusan National University School of Medicine, Busan, Korea
| | - Yong Ki Kim
- Kim Yong Ki Internal Medicine Clinic, Busan, Korea
| | - In Joo Kim
- Department of Internal Medicine, Pusan National University School of Medicine, Busan, Korea
- Medical Research Institute, Pusan National University School of Medicine, Busan, Korea
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Hong SH, Jiang X, Chen L, Josh P, Shin DG, Rowe D. Computer-Automated Static, Dynamic and Cellular Bone Histomorphometry. ACTA ACUST UNITED AC 2014; Suppl 1:004. [PMID: 25019033 PMCID: PMC4090931 DOI: 10.4172/2157-7552.s1-004] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
Abstract
Dynamic and cellular histomorphometry of trabeculae is the most
biologically relevant way of assessing steady state bone health. Traditional
measurement involves manual visual feature identification by a trained and
qualified professional. Inherent with this methodology is the time and cost
expenditure, as well as the subjectivity that naturally arises under human
visual inspection. In this work, we propose a rapidly deployable, automated, and
objective method for dynamic histomorphometry. We demonstrate that our method is
highly effective in assessing cellular activities in distal femur and vertebra
of mice which are injected with calcein and alizarin complexone 7 and 2 days
prior to sacrifice. The mineralized bone tissues of mice are cryosectioned using
a tape transfer protocol. A sequential workflow is implemented in which
endogenous fluorescent signals (bone mineral, green and red mineralization
lines), tartrate resistant acid phosphatase identified by ELF-97 and alkaline
phosphatase identified by Fast Red are captured as individual tiled images of
the section for each fluorescent color. All the images are then submitted to an
image analysis pipeline that automates identification of the mineralized regions
of bone and selection of a region of interest. The TRAP and AP stained images
are aligned to the mineralized image using strategically placed fluorescent
registration beads. Fluorescent signals are identified and are related to the
trabecular surface within the ROI. Subsequently, the pipelined method computes
static measurements, dynamic measurements, and cellular activities of osteoclast
and osteoblast related to the trabecular surface. Our method has been applied to
the distal femurs and vertebrae of 8 and 16 week old male and female C57Bl/6J
mice. The histomorphometric results reveal a significantly greater bone turnover
rate in female in contrast to male irrespective of age, validating similar
outcomes reported by other studies.
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Affiliation(s)
- Seung-Hyun Hong
- Department of Computer Science and Engineering, University of Connecticut, Storrs, Connecticut, USA
| | - Xi Jiang
- Department of Reconstructive Sciences, Biomaterials and Skeletal Development School of Dental Medicine, University of Connecticut Health Center, Farmington, Connecticut
| | - Li Chen
- Department of Reconstructive Sciences, Biomaterials and Skeletal Development School of Dental Medicine, University of Connecticut Health Center, Farmington, Connecticut
| | - Pujan Josh
- Department of Computer Science and Engineering, University of Connecticut, Storrs, Connecticut, USA
| | - Dong-Guk Shin
- Department of Computer Science and Engineering, University of Connecticut, Storrs, Connecticut, USA
| | - David Rowe
- Department of Reconstructive Sciences, Biomaterials and Skeletal Development School of Dental Medicine, University of Connecticut Health Center, Farmington, Connecticut
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Hattori S, Park JH, Agata U, Akimoto T, Oda M, Higano M, Aikawa Y, Nabekura Y, Yamato H, Ezawa I, Omi N. Influence of food restriction combined with voluntary running on bone morphology and strength in male rats. Calcif Tissue Int 2013; 93:540-8. [PMID: 24002179 DOI: 10.1007/s00223-013-9787-6] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/16/2013] [Accepted: 08/19/2013] [Indexed: 01/20/2023]
Abstract
Athletes, in particular endurance athletes and dancers, are chronically exposed to a state of low energy availability due to insufficient dietary energy intake and massive exercise energy expenditure. Low energy availability sometimes causes bone fragility, thereby increasing the risk of bone disorders. Although the decrease in energy availability shows no sexual dimorphism, epidemiological studies have reported that bone disorders are less frequent in male athletes than in female athletes. We hypothesized that bone tissue was not affected by low energy availability in males. The purpose of this study was to examine the influence of food restriction combined with voluntary running training on bone morphology and strength in adult male rats. Fourteen-week-old male Sprague-Dawley rats were divided randomly into four groups: control (C) group, food restriction (R) group, exercise (Ex) group, and food restriction plus exercise (REx) group. For the R and REx groups, 30 % food restriction was carried out in comparison with the C group. Bone strength, bone mineral density (BMD), bone architecture, and bone turnover rate were measured after a 13-week experimental period. Bone strength was not significantly lower in the REx group compared with the C group. BMD and trabecular bone volume showed no difference among groups. These findings indicate that bone morphology and strength were little affected by food restriction combined with exercise training in adult male rats.
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Affiliation(s)
- Satoshi Hattori
- Comprehensive Human Sciences, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki, 305-8572, Japan
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Shen CL, Zhu W, Gao W, Wang S, Chen L, Chyu MC. Energy-restricted diet benefits body composition but degrades bone integrity in middle-aged obese female rats. Nutr Res 2013; 33:668-76. [DOI: 10.1016/j.nutres.2013.05.008] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2013] [Revised: 05/08/2013] [Accepted: 05/13/2013] [Indexed: 10/26/2022]
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Brown-Borg HM, Rakoczy S. Metabolic adaptations to short-term every-other-day feeding in long-living Ames dwarf mice. Exp Gerontol 2013; 48:905-19. [PMID: 23832075 DOI: 10.1016/j.exger.2013.06.009] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2013] [Revised: 06/24/2013] [Accepted: 06/27/2013] [Indexed: 10/26/2022]
Abstract
Restrictive dietary interventions exert significant beneficial physiological effects in terms of aging and age-related disease in many species. Every other day feeding (EOD) has been utilized in aging research and shown to mimic many of the positive outcomes consequent with dietary restriction. This study employed long living Ames dwarf mice subjected to EOD feeding to examine the adaptations of the oxidative phosphorylation and antioxidative defense systems to this feeding regimen. Every other day feeding lowered liver glutathione (GSH) concentrations in dwarf and wild type (WT) mice but altered GSH biosynthesis and degradation in WT mice only. The activities of liver OXPHOS enzymes and corresponding proteins declined in WT mice fed EOD while in dwarf animals, the levels were maintained or increased with this feeding regimen. Antioxidative enzymes were differentially affected depending on the tissue, whether proliferative or post-mitotic. Gene expression of components of liver methionine metabolism remained elevated in dwarf mice when compared to WT mice as previously reported however, enzymes responsible for recycling homocysteine to methionine were elevated in both genotypes in response to EOD feeding. The data suggest that the differences in anabolic hormone levels likely affect the sensitivity of long living and control mice to this dietary regimen, with dwarf mice exhibiting fewer responses in comparison to WT mice. These results provide further evidence that dwarf mice may be better protected against metabolic and environmental perturbations which may in turn, contribute to their extended longevity.
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Affiliation(s)
- Holly M Brown-Borg
- Department of Pharmacology, Physiology and Therapeutics, University of North Dakota School of Medicine and Health Sciences, Grand Forks, ND 58202, USA.
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Chapnik N, Solomon G, Genzer Y, Miskin R, Gertler A, Froy O. A superactive leptin antagonist alters metabolism and locomotion in high-leptin mice. J Endocrinol 2013; 217:283-90. [PMID: 23482705 DOI: 10.1530/joe-13-0033] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Transgenic alpha murine urokinase-type plasminogen activator (αMUPA) mice are resistant to obesity and their locomotor activity is altered. As these mice have high leptin levels, our objective was to test whether leptin is responsible for these characteristics. αMUPA, their genetic background control (FVB/N), and C57BL mice were injected s.c. every other day with 20 mg/kg pegylated superactive mouse leptin antagonist (PEG-SMLA) for 6 weeks. We tested the effect of PEG-SMLA on body weight, locomotion, and bone health. The antagonist led to a rapid increase in body weight and subsequent insulin resistance in all treated mice. Food intake of PEG-SMLA-injected animals increased during the initial period of the experiment but then declined to a similar level to that of the control animals. Interestingly, αMUPA mice were found to have reduced bone volume (BV) than FVB/N mice, although PEG-SMLA increased bone mass in both strains. In addition, PEG-SMLA led to disrupted locomotor activity and increased corticosterone levels in C57BL but decreased levels in αMUPA or FVB/N mice. These results suggest that leptin is responsible for the lean phenotype and reduced BV in αMUPA mice; leptin affects corticosterone levels in mice in a strain-specific manner; and leptin alters locomotor activity, a behavior determined by the central circadian clock.
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Affiliation(s)
- Nava Chapnik
- Robert H Smith Faculty of Agriculture, Food and Environment, Institute of Biochemistry, Food Science and Nutrition, The Hebrew University of Jerusalem, Rehovot 76100, Israel
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Inactivation of Socs3 in the hypothalamus enhances the hindbrain response to endogenous satiety signals via oxytocin signaling. J Neurosci 2013. [PMID: 23197703 DOI: 10.1523/jneurosci.1669-12.2012] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Leptin is an adipocyte-derived hormone that controls energy balance by acting primarily in the CNS, but its action is lost in common forms of obesity due to central leptin resistance. One potential mechanism for such leptin resistance is an increased hypothalamic expression of Suppressor of cytokine signaling 3 (Socs3), a feedback inhibitor of the Jak-Stat pathway that prevents Stat3 activation. Ample studies have confirmed the important role of Socs3 in leptin resistance and obesity. However, the degree to which Socs3 participates in the regulation of energy homeostasis in nonobese conditions remains largely undetermined. In this study, using adult mice maintained under standard diet, we demonstrate that Socs3 deficiency in the mediobasal hypothalamus (MBH) reduces food intake, protects against body weight gain, and limits adiposity, suggesting that Socs3 is necessary for normal body weight maintenance. Mechanistically, MBH Socs3-deficient mice display increased hindbrain sensitivity to endogenous, meal-related satiety signals, mediated by oxytocin signaling. Thus, oxytocin signaling likely mediates the effect of hypothalamic leptin on satiety circuits of the caudal brainstem. This provides an anatomical substrate for the effect of leptin on meal size, and more generally, a mechanism for how the brain controls short-term food intake as a function of the energetic stores available in the organism to maintain energy homeostasis. Any dysfunction in this pathway could potentially lead to overeating and obesity.
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36
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Ikeda K. [Bone metabolism and aging]. Nihon Ronen Igakkai Zasshi 2013; 50:211-212. [PMID: 23979242 DOI: 10.3143/geriatrics.50.211] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
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Baek K, Bloomfield SA. Blocking β-adrenergic signaling attenuates reductions in circulating leptin, cancellous bone mass, and marrow adiposity seen with dietary energy restriction. J Appl Physiol (1985) 2012; 113:1792-801. [PMID: 22995391 DOI: 10.1152/japplphysiol.00187.2012] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
We tested whether β-adrenergic blockade attenuates bone loss and increased marrow adiposity during energy restriction (ER) and whether such an effect is associated with changes in serum leptin and leptin expression in bone and marrow tissues. Female 4-mo-old Sprague-Dawley rats were assigned into four groups (n = 10 each): two groups of 40% ER treated with vehicle (ERVEH; saline) or β-blocker (ERBB; DL-propranolol; 250 μg · kg(-1) · h(-1)) during 12 wk, and two groups of ad libitum-fed controls treated with the same two agents (CONVEH, CONBB, respectively). Over 84 days, CONVEH and CONBB rats gained but ERVEH and ERBB rats lost body fat mass; lean mass did not change in any group. Reduction in serum leptin in ERVEH rats was mitigated in ERBB rats (-5.32 vs. -1.15 ng/ml, respectively). The decline in proximal tibia cancellous vBMD observed in ERVEH rats was attenuated in ERBB rats (-85.24 vs. -53.94 mg/cm(3), respectively). Adipocyte number in ERVEH rats was dramatically higher vs. CON rats at week 12, but this increment was abolished by β-blockade in ERBB animals. The number of osteoblastic cells and marrow adipocytes staining positively for leptin in ERVEH rats tended to be lower vs. that of both CON groups, but β-blockade appears to reverse this effect in ERBB rats. In summary, β-adrenergic blockade mitigated metaphyseal bone loss and bone marrow adiposity during energy restriction and attenuated reductions in serum leptin. These data suggest an important role for β-adrenoreceptor signaling pathway in the cancellous bone and marrow fat response to energy restriction.
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Affiliation(s)
- Kyunghwa Baek
- Department of Health and Kinesiology and Intercollegiate Graduate Faculty of Nutrition, Texas A&M University, College Station, Texas 77843, USA
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Zhang Y, Zhou P, Kimondo JW. Adiponectin and osteocalcin: relation to insulin sensitivity. Biochem Cell Biol 2012; 90:613-20. [PMID: 22812431 DOI: 10.1139/o2012-022] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Obesity and osteoporosis have grave consequences for human health, quality of life, and even the efficiency of the labor force. Interestingly, these diseases share several features including a genetic predisposition and a common progenitor cell. Recent findings show that high adipocyte count in bone marrow is directly related to bone loss, as fat cells replace osteoblasts resulting in reduced bone mineral density and increased propensity towards osteoporosis. This close relationship has a positive aspect, whereby higher osteocalcin levels results in increased adiponectin production while the presence of adiponectin influences osteoblast proliferation and differentiation in a positive way. We focus on how osteoblasts and adipocytes affect each other and ultimately insulin resistance through the hormones they produce. This approach to whole animal physiology is the main stay of Alternative Medicine. It is assumed that the body is linked together intricately, and treating one is equal to treating the whole body. As we go further into bone and adipocytes physiology, it is evident that these organs affect each other. Therefore, elucidation on the actions of fat on bone and vice versa will unravel the complex mechanism of insulin resistance.
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Affiliation(s)
- Yanjun Zhang
- Tianjin University of Traditional Chinese Medicine, School of Chinese Medicine, Tianjin, PR China
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Devlin MJ, Bouxsein ML. Influence of pre- and peri-natal nutrition on skeletal acquisition and maintenance. Bone 2012; 50:444-51. [PMID: 21723972 PMCID: PMC3210869 DOI: 10.1016/j.bone.2011.06.019] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/12/2011] [Revised: 05/30/2011] [Accepted: 06/15/2011] [Indexed: 11/29/2022]
Abstract
Early life nutrition has substantial influences on postnatal health, with both under- and overnutrition linked with permanent metabolic changes that alter reproductive and immune function and significantly increase metabolic disease risk in offspring. Since perinatal nutrition depends in part on maternal metabolic condition, maternal diet during gestation and lactation is a risk factor for adult metabolic disease. Such developmental responses may be adaptive, but might also result from constraints on, or pathological changes to, normal physiology. The rising prevalence of both obesity and osteoporosis, and the identification of links among bone, fat, brain, and gut, suggest that obesity and osteoporosis may be related, and moreover that their roots may lie in early life. Here we focus on evidence for how maternal diet during gestation and lactation affects metabolism and skeletal acquisition in humans and in animal models. We consider the effects of overall caloric restriction, and macronutrient imbalances including high fat, high sucrose, and low protein, compared to normal diet. We then discuss potential mechanisms underlying the skeletal responses, including perinatal developmental programming via disruption of the perinatal leptin surge and/or epigenetic changes, to highlight unanswered questions and identify the most critical areas for future research.
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Affiliation(s)
- M J Devlin
- Center for Advanced Orthopedic Studies, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, MA 02215, USA.
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Yanaka K, Higuchi M, Ishimi Y. Effect of long-term voluntary exercise and energy restriction on bone mineral density in mature female rats. THE JOURNAL OF PHYSICAL FITNESS AND SPORTS MEDICINE 2012. [DOI: 10.7600/jpfsm.1.695] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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Shah K, Armamento-Villareal R, Parimi N, Chode S, Sinacore DR, Hilton TN, Napoli N, Qualls C, Villareal DT. Exercise training in obese older adults prevents increase in bone turnover and attenuates decrease in hip bone mineral density induced by weight loss despite decline in bone-active hormones. J Bone Miner Res 2011; 26:2851-9. [PMID: 21786319 PMCID: PMC3206995 DOI: 10.1002/jbmr.475] [Citation(s) in RCA: 128] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
Weight loss therapy to improve health in obese older adults is controversial because it causes further bone loss. Therefore, it is recommended that weight loss therapy should include an intervention such as exercise training (ET) to minimize bone loss. The purpose of this study was to determine the independent and combined effects of weight loss and ET on bone metabolism in relation to bone mineral density (BMD) in obese older adults. One-hundred-seven older (age >65 years) obese (body mass index [BMI] ≥ 30 kg/m(2) ) adults were randomly assigned to a control group, diet group, exercise group, and diet-exercise group for 1 year. Body weight decreased in the diet (-9.6%) and diet-exercise (-9.4%) groups, not in the exercise (-1%) and control (-0.2%) groups (between-group p < 0.001). However, despite comparable weight loss, bone loss at the total hip was relatively less in the diet-exercise group (-1.1%) than in the diet group (-2.6%), whereas BMD increased in the exercise group (1.5%) (between-group p < 0.001). Serum C-terminal telopeptide (CTX) and osteocalcin concentrations increased in the diet group (31% and 24%, respectively), whereas they decreased in the exercise group (-13% and -15%, respectively) (between-group p < 0.001). In contrast, similar to the control group, serum CTX and osteocalcin concentrations did not change in the diet-exercise group. Serum procollagen propeptide concentrations decreased in the exercise group (-15%) compared with the diet group (9%) (p = 0.04). Serum leptin and estradiol concentrations decreased in the diet (-25% and -15%, respectively) and diet-exercise (-38% and -13%, respectively) groups, not in the exercise and control groups (between-group p = 0.001). Multivariate analyses revealed that changes in lean body mass (β = 0.33), serum osteocalcin (β = -0.24), and one-repetition maximum (1-RM) strength (β = 0.23) were independent predictors of changes in hip BMD (all p < 0.05). In conclusion, the addition of ET to weight loss therapy among obese older adults prevents weight loss-induced increase in bone turnover and attenuates weight loss-induced reduction in hip BMD despite weight loss-induced decrease in bone-active hormones.
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Affiliation(s)
- Krupa Shah
- Division of Geriatrics and Nutritional Science, Washington University School of Medicine, St. Louis, MO, USA
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Esteban Lezón C, Pintos PM, Itatí Olivera MI, Bozzini C, Boyer PM. [Effect of different propranolol doses on skeletal structural and mechanic efficiency in an animal model of growth retardation]. ACTA ACUST UNITED AC 2011; 59:9-20. [PMID: 22094148 DOI: 10.1016/j.endonu.2011.09.006] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2011] [Revised: 09/15/2011] [Accepted: 09/19/2011] [Indexed: 01/14/2023]
Abstract
OBJECTIVE To assess in a growth retardation (GR) model the impact of different propranolol (P) doses on anthropomorphometric and biomechanical variables of the appendicular skeleton. MATERIALS AND METHODS Twenty-one day-old male Wistar rats were divided into the following groups: control (C), C+P3.5 (CP3.5); C+P7 (CP7); C+P10.5 (CP10.5); C+P14 (CP14); ED, ED+P3.5 (EDP3.5); ED+P7 (EDP7); ED+P10.5 (EDP10.5), and ED+P14 (EDP14). Control animals with/without P were fed a rodent diet ad libitum. GR rats with/without P were given 80% of the same diet per 100g body weight for 4 weeks (T4). Propranolol 3.5, 7, 10.5, and 14 mg/kg/day was intraperitoneally injected 5 days/week for 4 weeks to the CP3.5 and EDP3.5; CP7 and EDP7; CP10.5 and EDP10.5, and CP14 and EDP14 groups respectively. RESULTS At T4, energy restriction had negative effects upon overall growth, femur, and its mechanical competence. Propranolol improved bone rigidity in GR animals at doses of 7 and 10.5mg/kg/day, with a maximum response at 7 mg/kg/day. CONCLUSIONS Propranolol 7 mg/kg/day would be the most effective dose for modeling incorporation of bone, as shown by the increased skeletal structural and mechanic efficiency in this animal model of growth retardation. Such effect may result from maintenance of mechanosensor viability, changes in its sensitivity, the biomechanical reference point and/or effector response in GR rats.
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Devlin MJ. Why does starvation make bones fat? Am J Hum Biol 2011; 23:577-85. [PMID: 21793093 DOI: 10.1002/ajhb.21202] [Citation(s) in RCA: 67] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2010] [Revised: 04/27/2011] [Accepted: 05/30/2011] [Indexed: 12/20/2022] Open
Abstract
Body fat, or adipose tissue, is a crucial energetic buffer against starvation in humans and other mammals, and reserves of white adipose tissue (WAT) rise and fall in parallel with food intake. Much less is known about the function of bone marrow adipose tissue (BMAT), which are fat cells found in bone marrow. BMAT mass actually increases during starvation, even as other fat depots are being mobilized for energy. This review considers several possible reasons for this poorly understood phenomenon. Is BMAT a passive filler that occupies spaces left by dying bone cells, a pathological consequence of suppressed bone formation, or potentially an adaptation for surviving starvation? These possibilities are evaluated in terms of the effects of starvation on the body, particularly the skeleton, and the mechanisms involved in storing and metabolizing BMAT during negative energy balance.
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Affiliation(s)
- Maureen J Devlin
- Center for Advanced Orthopaedic Studies, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, Massachusetts 02215, USA.
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Turner RT, Iwaniec UT. Low dose parathyroid hormone maintains normal bone formation in adult male rats during rapid weight loss. Bone 2011; 48:726-32. [PMID: 21215827 PMCID: PMC3062670 DOI: 10.1016/j.bone.2010.12.034] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/05/2010] [Revised: 12/12/2010] [Accepted: 12/28/2010] [Indexed: 02/06/2023]
Abstract
A persistent negative energy balance results in bone loss. It is not clear whether the bone loss associated with chronic negative energy balance can be prevented. The objective of this study was to assess the efficacy of intermittent low dose parathyroid hormone (PTH) treatment in maintaining normal bone formation during severe energy restriction. Six-month-old male Fisher 344 rats were divided into 4 treatment groups: (1) baseline, (2) ad libitum (ad lib)-fed control, (3) energy-restricted (to consume 40% ad lib caloric intake), or (4) energy-restricted+low dose (1 μg/kg/d) PTH. Severe energy restriction for 14 d decreased body weight and serum leptin levels. Compared to ad lib-fed controls, energy-restricted rats had lower cancellous bone formation, higher osteoclast perimeter/bone perimeter and higher bone marrow adiposity in the proximal tibial metaphysis. Also, the energy-restricted rats had a lower periosteal bone formation rate at the tibia-fibula synostosis. Administration of PTH to energy-restricted rats had no effect on weight loss or osteoclast perimeter/bone perimeter. In contrast, energy-restricted rats treated with PTH had higher rates of cancellous and cortical bone formation compared to energy-restricted rats, and did not differ from the ad lib-fed control animals. Furthermore, PTH treatment maintained normal bone marrow adiposity. In conclusion, rapid weight loss in adult male rats was accompanied by decreased bone formation and increased bone marrow adiposity and these changes were prevented by low dose PTH treatment. Taken together, the results suggest that the energy cost of bone formation in adult rats is low and PTH therapy is effective in preventing the reduced bone formation associated with rapid weight loss.
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Affiliation(s)
| | - Urszula T. Iwaniec
- Skeletal Biology Laboratory, Oregon State University, Corvallis, OR
- Corresponding author: Urszula T. Iwaniec, Ph.D., Skeletal Biology Laboratory, 108 Milam Hall, Oregon State University, Corvallis, OR 97331, Tel: 541-737-9925, Fax: 541-737-6914,
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Villareal DT, Kotyk JJ, Armamento-Villareal RC, Kenguva V, Seaman P, Shahar A, Wald MJ, Kleerekoper M, Fontana L. Reduced bone mineral density is not associated with significantly reduced bone quality in men and women practicing long-term calorie restriction with adequate nutrition. Aging Cell 2011; 10:96-102. [PMID: 20969721 DOI: 10.1111/j.1474-9726.2010.00643.x] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Calorie restriction (CR) reduces bone quantity but not bone quality in rodents. Nothing is known regarding the long-term effects of CR with adequate intake of vitamin and minerals on bone quantity and quality in middle-aged lean individuals. In this study, we evaluated body composition, bone mineral density (BMD), and serum markers of bone turnover and inflammation in 32 volunteers who had been eating a CR diet (approximately 35% less calories than controls) for an average of 6.8 ± 5.2 years (mean age 52.7 ± 10.3 years) and 32 age- and sex-matched sedentary controls eating Western diets (WD). In a subgroup of 10 CR and 10 WD volunteers, we also measured trabecular bone (TB) microarchitecture of the distal radius using high-resolution magnetic resonance imaging. We found that the CR volunteers had significantly lower body mass index than the WD volunteers (18.9 ± 1.2 vs. 26.5 ± 2.2 kg m(-2) ; P = 0.0001). BMD of the lumbar spine (0.870 ± 0.11 vs. 1.138 ± 0.12 g cm(-2) , P = 0.0001) and hip (0.806 ± 0.12 vs. 1.047 ± 0.12 g cm(-2) , P = 0.0001) was also lower in the CR than in the WD group. Serum C-terminal telopeptide and bone-specific alkaline phosphatase concentration were similar between groups, while serum C-reactive protein (0.19 ± 0.26 vs. 1.46 ± 1.56 mg L(-1) , P = 0.0001) was lower in the CR group. Trabecular bone microarchitecture parameters such as the erosion index (0.916 ± 0.087 vs. 0.877 ± 0.088; P = 0.739) and surface-to-curve ratio (10.3 ± 1.4 vs. 12.1 ± 2.1, P = 0.440) were not significantly different between groups. These findings suggest that markedly reduced BMD is not associated with significantly reduced bone quality in middle-aged men and women practicing long-term calorie restriction with adequate nutrition.
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Affiliation(s)
- Dennis T Villareal
- Division of Geriatrics and Nutritional Science, Washington University School of Medicine, 660 S. Euclid Avenue, St. Louis, MO 63110, USA
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Cerqueira FM, Kowaltowski AJ. Commonly adopted caloric restriction protocols often involve malnutrition. Ageing Res Rev 2010; 9:424-30. [PMID: 20493280 DOI: 10.1016/j.arr.2010.05.002] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2010] [Revised: 05/10/2010] [Accepted: 05/10/2010] [Indexed: 02/08/2023]
Abstract
Undernutrition without malnutrition is an intervention that enhances laboratory animal life span, and is widely studied to uncover factors limiting longevity. In a search of the literature over a course of four years, we found that most protocols currently adopted as caloric restriction do not meet micronutrient standards set by the National Research Council for laboratory rats and mice. We provide evidence that the most commonly adopted caloric restriction protocol, a 40% restriction of the AIN-93 diet without vitamin or mineral supplementation, leads to malnutrition in both mice and rats. Furthermore, others and we find that every other day feeding, another dietary intervention often referred to as caloric restriction, does not limit the total amount of calories consumed. Altogether, we propose that the term "caloric restriction" should be used specifically to describe diets that decrease calorie intake but not micronutrient availability, and that protocols adopted should be described in detail in order to allow for comparisons and better understanding of the effects of these diets.
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Devlin MJ, Cloutier AM, Thomas NA, Panus DA, Lotinun S, Pinz I, Baron R, Rosen CJ, Bouxsein ML. Caloric restriction leads to high marrow adiposity and low bone mass in growing mice. J Bone Miner Res 2010; 25:2078-88. [PMID: 20229598 PMCID: PMC3127399 DOI: 10.1002/jbmr.82] [Citation(s) in RCA: 253] [Impact Index Per Article: 18.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/11/2009] [Revised: 02/11/2010] [Accepted: 03/04/2010] [Indexed: 12/12/2022]
Abstract
The effects of caloric restriction (CR) on the skeleton are well studied in adult rodents and include lower cortical bone mass but higher trabecular bone volume. Much less is known about how CR affects bone mass in young, rapidly growing animals. This is an important problem because low caloric intake during skeletal acquisition in humans, as in anorexia nervosa, is associated with low bone mass, increased fracture risk, and osteoporosis in adulthood. To explore this question, we tested the effect of caloric restriction on bone mass and microarchitecture during rapid skeletal growth in young mice. At 3 weeks of age, we weaned male C57Bl/6J mice onto 30% caloric restriction (10% kcal/fat) or normal diet (10% kcal/fat). Outcomes at 6 (n = 4/group) and 12 weeks of age (n = 8/group) included body mass, femur length, serum leptin and insulin-like growth factor 1 (IGF-1) values, whole-body bone mineral density (WBBMD, g/cm(2)), cortical and trabecular bone architecture at the midshaft and distal femur, bone formation and cellularity, and marrow fat measurement. Compared with the normal diet, CR mice had 52% and 88% lower serum leptin and 33% and 39% lower serum IGF-1 at 6 and 12 weeks of age (p < .05 for all). CR mice were smaller, with lower bone mineral density, trabecular, and cortical bone properties. Bone-formation indices were lower, whereas bone-resorption indices were higher (p < .01 for all) in CR versus normal diet mice. Despite having lower percent of body fat, bone marrow adiposity was elevated dramatically in CR versus normal diet mice (p < .05). Thus we conclude that caloric restriction in young, growing mice is associated with impaired skeletal acquisition, low leptin and IGF-1 levels, and high marrow adiposity. These results support the hypothesis that caloric restriction during rapid skeletal growth is deleterious to cortical and trabecular bone mass and architecture, in contrast to potential skeletal benefits of CR in aging animals.
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Affiliation(s)
- Maureen J Devlin
- Center for Advanced Orthopedic Studies, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, MA 02215, USA.
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Baur JA. Resveratrol, sirtuins, and the promise of a DR mimetic. Mech Ageing Dev 2010; 131:261-9. [PMID: 20219519 PMCID: PMC2862768 DOI: 10.1016/j.mad.2010.02.007] [Citation(s) in RCA: 161] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2009] [Revised: 02/13/2010] [Accepted: 02/20/2010] [Indexed: 12/24/2022]
Abstract
Dietary restriction (DR) delays or prevents age-related diseases and extends lifespan in species ranging from yeast to primates. Although the applicability of this regimen to humans remains uncertain, a proportional response would add more healthy years to the average life than even a cure for cancer or heart disease. Because it is unlikely that many would be willing or able to maintain a DR lifestyle, there has been intense interest in mimicking its beneficial effects on health, and potentially longevity, with drugs. To date, such efforts have been hindered primarily by our lack of mechanistic understanding of how DR works. Sirtuins, NAD(+)-dependent deacetylases and ADP-ribosyltransferases that influence lifespan in lower organisms, have been proposed to be key mediators of DR, and based on this model, the sirtuin activator resveratrol has been proposed as a candidate DR mimetic. Indeed, resveratrol extends lifespan in yeast, worms, flies, and a short-lived species of fish. In rodents, resveratrol improves health, and prevents the early mortality associated with obesity, but its precise mechanism of action remains a subject of debate, and extension of normal lifespan has not been observed. This review summarizes recent work on resveratrol, sirtuins, and their potential to mimic beneficial effects of DR.
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Affiliation(s)
- Joseph A Baur
- Institute for Diabetes, Obesity, and Metabolism, Department of Physiology, University of Pennsylvania School of Medicine, Philadelphia, PA 19104, USA.
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Yamamoto T, Carrero JJ, Lindholm B, Stenvinkel P, Axelsson J. Leptin and Uremic Protein-Energy Wasting-The Axis of Eating. Semin Dial 2009; 22:387-90. [DOI: 10.1111/j.1525-139x.2009.00586.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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50
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