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Oku Y, Noda S, Ishii S, Yamada A, Nakaoka K, Goseki-Sone M. Calcium restriction for 28 days markedly and negatively influences bone mineral density of the femur and lumbar vertebrae regardless of the high-fat diet ingestion in young adult male rats. Nutr Res 2024; 124:55-64. [PMID: 38387406 DOI: 10.1016/j.nutres.2024.01.015] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2023] [Revised: 01/27/2024] [Accepted: 01/27/2024] [Indexed: 02/24/2024]
Abstract
Calcium (Ca) is necessary for bone calcification, and Ca deficiency leads to decreased bone mineral density (BMD). Epidemiological studies have reported a correlation between Ca intake and BMD. Although the influences of Ca deficiency on BMD have been reported, the effects of Ca restriction on bone during high-fat diet ingestion remain unclear. Therefore, we hypothesized that high-fat diet ingestion would potentiate the negative effects of Ca restriction on bone. Sprague-Dawley strain male rats (aged 11 weeks) were divided into 4 groups: basic control diet (Cont.) (11% lipid energy rate, 0.5% calcium), basic control diet with Ca restriction (CaR) (11% lipid energy rate, 0.02% calcium), high-fat diet (HF) (40% lipid energy rate, 0.5% calcium), and high-fat diet with Ca restriction (HFCaR) (40% lipid energy rate, 0.02% calcium). At 28 days after starting the experimental diets, body weights were higher in the high-fat diet groups (HF and HFCaR) than in the standard-fat diet groups (Cont. and CaR) on 2-way analysis of variance. The apparent Ca absorption rate in the Ca-restricted groups (CaR and HFCaR) was higher than in the Ca-sufficient groups (Cont. and HF). BMD and bone strength parameters of the femur and lumbar vertebrae in the Ca-restricted groups were markedly lower than in the Ca-sufficient groups, whereas there were no significant differences between the standard-fat diet and HF diet groups. These results suggest that 28 days of Ca restriction increases the risk of bone fracture and osteoporosis.
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Affiliation(s)
- Yuno Oku
- Department of Food and Nutrition, Faculty of Human Sciences and Design, Japan Women's University, Tokyo, Japan
| | - Seiko Noda
- Department of Food and Nutrition, Faculty of Human Sciences and Design, Japan Women's University, Tokyo, Japan
| | - Shiho Ishii
- Department of Food and Nutrition, Faculty of Human Sciences and Design, Japan Women's University, Tokyo, Japan
| | - Asako Yamada
- Department of Food and Nutrition, Faculty of Human Sciences and Design, Japan Women's University, Tokyo, Japan
| | - Kanae Nakaoka
- Department of Food and Nutrition, Faculty of Human Life, Jumonji University, Saitama, Japan
| | - Masae Goseki-Sone
- Department of Food and Nutrition, Faculty of Human Sciences and Design, Japan Women's University, Tokyo, Japan.
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2
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Tian N, Chen S, Han H, Jin J, Li Z. Association between triglyceride glucose index and total bone mineral density: a cross-sectional study from NHANES 2011-2018. Sci Rep 2024; 14:4208. [PMID: 38378872 PMCID: PMC10879154 DOI: 10.1038/s41598-024-54192-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2023] [Accepted: 02/09/2024] [Indexed: 02/22/2024] Open
Abstract
The Homeostatic Model Assessment for Triglyceride Glucose Index (TyG) and its related indices, including triglyceride glucose-waist circumference (TyG-WC), triglyceride glucose-waist-to-height ratio (TyG-WHtR) and triglyceride glucose-body mass index (TyG-BMI), has emerged as a practical tool for assessing insulin resistance in metabolic disorders. However, limited studies have explored the connection between TyG, TyG-related indices and osteoporosis. This population-based study, utilizing data from the National Health and Nutrition Examination Survey 2011-2018, involved 5456 participants. Through weighted multivariate linear regression and smoothed curve fitting, a significant positive correlation was found between TyG, TyG-related indices and total bone mineral density (BMD) after adjusting for covariates [β = 0.0124, 95% CI (0.0006, 0.0242), P = 0.0390; β = 0.0004, 95% CI (0.0003, 0.0004), P < 0.0001; β = 0.0116, 95% CI (0.0076, 0.0156), P < 0.0001; β = 0.0001, 95% CI (0.0001, 0.0001), P < 0.0001]. In subgroup analysis, race stratification significantly affected the relationship between TyG and total BMD. Additionally, gender and race were both significant for TyG-related indices. Non-linear relationships and threshold effects with inflection points at 9.106, 193.9265, 4.065, and 667.5304 (TyG, TyG-BMI, TyG-WHtR, TyG-WC) were identified. Saturation phenomena were observed between TyG-BMI, TyG-WC and total BMD with saturation thresholds at 314.177 and 1022.0428. These findings contributed to understanding the association between TyG, TyG-related indices and total BMD, offering insights for osteoporosis prevention and treatment.
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Affiliation(s)
- Ningsheng Tian
- Department of Orthopaedics, The Second Affiliated Hospital of Nanjing University of Chinese Medicine, No.23, Nanhu Road, Jianye District, Nanjing, 210017, Jiangsu Province, People's Republic of China
| | - Shuai Chen
- Department of Orthopaedics, The Second Affiliated Hospital of Nanjing University of Chinese Medicine, No.23, Nanhu Road, Jianye District, Nanjing, 210017, Jiangsu Province, People's Republic of China
| | - Huawei Han
- Department of Orthopaedics, The Second Affiliated Hospital of Nanjing University of Chinese Medicine, No.23, Nanhu Road, Jianye District, Nanjing, 210017, Jiangsu Province, People's Republic of China
| | - Jie Jin
- Department of Orthopaedics, The Second Affiliated Hospital of Nanjing University of Chinese Medicine, No.23, Nanhu Road, Jianye District, Nanjing, 210017, Jiangsu Province, People's Republic of China
| | - Zhiwei Li
- Department of Orthopaedics, The Second Affiliated Hospital of Nanjing University of Chinese Medicine, No.23, Nanhu Road, Jianye District, Nanjing, 210017, Jiangsu Province, People's Republic of China.
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Beaver LM, Prati M, Gilman KE, Luo T, Shay NF, Branscum AJ, Turner RT, Iwaniec UT. Diet composition influences the effect of high fat diets on bone in growing male mice. Bone 2023; 176:116888. [PMID: 37652285 DOI: 10.1016/j.bone.2023.116888] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/28/2023] [Revised: 08/26/2023] [Accepted: 08/28/2023] [Indexed: 09/02/2023]
Abstract
The effect of diet-induced obesity on bone in rodents is variable, with bone mass increases, decreases, and no impact reported. The goal of this study was to evaluate whether the composition of obesogenic diet may influence bone independent of its effect on body weight. As proof-of-principle, we used a mouse model to compare the skeletal effects of a commonly used high fat 'Western' diet and a modified high fat diet. The modified high fat diet included ground English walnut and was isocaloric for macronutrients, but differed in fatty acid composition and contained nutrients (e.g. polyphenols) not present in the standard 'Western' diet. Eight-week-old mice were randomized into 1 of 3 dietary treatments (n = 8/group): (1) low fat control diet (LF; 10 % kcal fat); (2) high fat 'Western' diet (HF; 46 % kcal fat as soybean oil and lard); or (3) modified high fat diet supplemented with ground walnuts (HF + walnut; 46 % kcal fat as soybean oil, lard, and walnut) and maintained on their respective diets for 9 weeks. Bone response in femur was then evaluated using dual energy x-ray absorptiometry, microcomputed tomography, and histomorphometry. Consumption of both obesogenic diets resulted in increased weight gain but differed in impact on bone and bone marrow adiposity in distal femur metaphysis. Mice consuming the high fat 'Western' diet exhibited a tendency for lower cancellous bone volume fraction and connectivity density, and had lower osteoblast-lined bone perimeter (an index of bone formation) and higher bone marrow adiposity than low fat controls. Mice fed the modified high fat diet did not differ from mice fed control (low fat) diet in cancellous bone microarchitecture, or osteoblast-lined bone perimeter, and exhibited lower bone marrow adiposity compared to mice fed the 'Western' diet. This proof-of-principal study demonstrates that two obesogenic diets, similar in macronutrient distribution and induction of weight gain, can have different effects on cancellous bone in distal femur metaphysis. Because the composition of the diets used to induce obesity in rodents does not recapitulate a common human diet, our finding challenges the translatability of rodent studies evaluating the impact of diet-induced obesity on bone.
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Affiliation(s)
- Laura M Beaver
- Skeletal Biology Laboratory, School of Biological and Population Health Sciences, Oregon State University, Corvallis, OR, USA; Linus Pauling Institute, Oregon State University, Corvallis, OR, USA
| | - Maud Prati
- Food Science and Technology, Oregon State University, Corvallis, OR, USA
| | - Kristy E Gilman
- Skeletal Biology Laboratory, School of Biological and Population Health Sciences, Oregon State University, Corvallis, OR, USA
| | - Ting Luo
- Food Science and Technology, Oregon State University, Corvallis, OR, USA
| | - Neil F Shay
- Food Science and Technology, Oregon State University, Corvallis, OR, USA
| | - Adam J Branscum
- Biostatistics Program, School of Biological and Population Health Sciences, Oregon State University, Corvallis, OR, USA
| | - Russell T Turner
- Skeletal Biology Laboratory, School of Biological and Population Health Sciences, Oregon State University, Corvallis, OR, USA; Center for Healthy Aging Research, Oregon State University, Corvallis, OR, USA
| | - Urszula T Iwaniec
- Skeletal Biology Laboratory, School of Biological and Population Health Sciences, Oregon State University, Corvallis, OR, USA; Center for Healthy Aging Research, Oregon State University, Corvallis, OR, USA.
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Williamson A, da Silva A, do Carmo JM, Le Maitre C, Hall JE, Aberdein N. Impact of leptin deficiency on male tibia and vertebral body 3D bone architecture independent of changes in body weight. Physiol Rep 2023; 11:10.14814/phy2.15832. [PMID: 37786973 PMCID: PMC10546263 DOI: 10.14814/phy2.15832] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2023] [Revised: 09/12/2023] [Accepted: 09/12/2023] [Indexed: 10/04/2023] Open
Abstract
Leptin an adipokine with potent effects on energy balance and body weight plays an important role in defining bone architecture in growing mammals. However, major changes in body weight can also influence morphology of trabecular and cortical bone. Therefore, we examined the impact of leptin deficiency on tibia and vertebral body 3D bone architecture independent of changes in body weight. Furthermore, advances in computational 3D image analysis suggest that average morphological values may mask regional specific differences in trabecular bone thickness. The study utilized leptin-deficient Ob/Ob mice (n = 8) weight-paired to C57BL/6 (C57) control mice (n = 8) which were split into either lean or obese groups for 24 ± 2 weeks. Whole tibias and L3 vertebrae were fixed before high resolution microcomputed tomography (μCT) scanning was performed. Leptin deficiency independent of body weight reduced tibia cortical bone volume, trabecular bone volume/tissue volume, number, and mineral density. Mean tibia trabecular thickness showed no significant differences between all groups; however, significant changes in trabecular thickness were found when analyzed by region. This study demonstrates that leptin deficiency significantly impacts tibia and vertebral body trabecular and cortical bone 3D architecture independent of changes in body weight.
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Affiliation(s)
- Alexander Williamson
- Biomolecular Science Research Centre, Department of Bioscience and ChemistrySheffield Hallam UniversitySheffieldUK
| | - Alexandre da Silva
- Mississippi Center for Obesity Research, Department of Physiology and BiophysicsUniversity of Mississippi Medical CenterJacksonMississippiUSA
| | - Jussara M. do Carmo
- Mississippi Center for Obesity Research, Department of Physiology and BiophysicsUniversity of Mississippi Medical CenterJacksonMississippiUSA
| | - Christine L. Le Maitre
- Biomolecular Science Research Centre, Department of Bioscience and ChemistrySheffield Hallam UniversitySheffieldUK
| | - John E. Hall
- Mississippi Center for Obesity Research, Department of Physiology and BiophysicsUniversity of Mississippi Medical CenterJacksonMississippiUSA
| | - Nicola Aberdein
- Biomolecular Science Research Centre, Department of Bioscience and ChemistrySheffield Hallam UniversitySheffieldUK
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5
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Pierce JL, Sharma AK, Roberts RL, Yu K, Irsik DL, Choudhary V, Dorn JS, Bensreti H, Benson RD, Kaiser H, Khayrullin A, Davis C, Wehrle CJ, Johnson MH, Bollag WB, Hamrick MW, Shi X, Isales CM, McGee-Lawrence ME. The Glucocorticoid Receptor in Osterix-Expressing Cells Regulates Bone Mass, Bone Marrow Adipose Tissue, and Systemic Metabolism in Female Mice During Aging. J Bone Miner Res 2022; 37:285-302. [PMID: 34747055 PMCID: PMC9976194 DOI: 10.1002/jbmr.4468] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/05/2021] [Revised: 09/23/2021] [Accepted: 10/17/2021] [Indexed: 12/18/2022]
Abstract
Hallmarks of aging-associated osteoporosis include bone loss, bone marrow adipose tissue (BMAT) expansion, and impaired osteoblast function. Endogenous glucocorticoid levels increase with age, and elevated glucocorticoid signaling, associated with chronic stress and dysregulated metabolism, can have a deleterious effect on bone mass. Canonical glucocorticoid signaling through the glucocorticoid receptor (GR) was recently investigated as a mediator of osteoporosis during the stress of chronic caloric restriction. To address the role of the GR in an aging-associated osteoporotic phenotype, the current study utilized female GR conditional knockout (GR-CKO; GRfl/fl :Osx-Cre+) mice and control littermates on the C57BL/6 background aged to 21 months and studied in comparison to young (3- and 6-month-old) mice. GR deficiency in Osx-expressing cells led to low bone mass and BMAT accumulation that persisted with aging. Surprisingly, however, GR-CKO mice also exhibited alterations in muscle mass (reduced % lean mass and soleus fiber size), accompanied by reduced voluntary physical activity, and also exhibited higher whole-body metabolic rate and elevated blood pressure. Moreover, increased lipid storage was observed in GR-CKO osteoblastic cultures in a glucocorticoid-dependent fashion despite genetic deletion of the GR, and could be reversed via pharmacological inhibition of the mineralocorticoid receptor (MR). These findings provide evidence of a role for the GR (and possibly the MR) in facilitating healthy bone maintenance with aging in females. The effects of GR-deficient bone on whole-body physiology also demonstrate the importance of bone as an endocrine organ and suggest evidence for compensatory mechanisms that facilitate glucocorticoid signaling in the absence of osteoblastic GR function; these represent new avenues of research that may improve understanding of glucocorticoid signaling in bone toward the development of novel osteogenic agents. © 2021 American Society for Bone and Mineral Research (ASBMR).
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Affiliation(s)
- Jessica L Pierce
- Department of Cellular Biology and Anatomy, Augusta University, Augusta, GA, USA
| | - Anuj K Sharma
- Department of Cellular Biology and Anatomy, Augusta University, Augusta, GA, USA
| | - Rachel L Roberts
- Department of Cellular Biology and Anatomy, Augusta University, Augusta, GA, USA
| | - Kanglun Yu
- Department of Cellular Biology and Anatomy, Augusta University, Augusta, GA, USA
| | - Debra L Irsik
- Department of Neuroscience and Regenerative Medicine, Augusta University, Augusta, GA, USA.,Charlie Norwood VA Medical Center, Augusta, GA, USA
| | - Vivek Choudhary
- Department of Physiology, Augusta University, Augusta, GA, USA
| | - Jennifer S Dorn
- Department of Cellular Biology and Anatomy, Augusta University, Augusta, GA, USA
| | - Husam Bensreti
- Department of Cellular Biology and Anatomy, Augusta University, Augusta, GA, USA
| | - Reginald D Benson
- Department of Cellular Biology and Anatomy, Augusta University, Augusta, GA, USA
| | - Helen Kaiser
- Department of Cellular Biology and Anatomy, Augusta University, Augusta, GA, USA
| | - Andrew Khayrullin
- Department of Cellular Biology and Anatomy, Augusta University, Augusta, GA, USA
| | - Colleen Davis
- Department of Cellular Biology and Anatomy, Augusta University, Augusta, GA, USA
| | - Chase J Wehrle
- Department of Cellular Biology and Anatomy, Augusta University, Augusta, GA, USA
| | - Maribeth H Johnson
- Department of Neuroscience and Regenerative Medicine, Augusta University, Augusta, GA, USA
| | - Wendy B Bollag
- Charlie Norwood VA Medical Center, Augusta, GA, USA.,Department of Physiology, Augusta University, Augusta, GA, USA
| | - Mark W Hamrick
- Department of Cellular Biology and Anatomy, Augusta University, Augusta, GA, USA
| | - Xingming Shi
- Department of Neuroscience and Regenerative Medicine, Augusta University, Augusta, GA, USA
| | - Carlos M Isales
- Department of Neuroscience and Regenerative Medicine, Augusta University, Augusta, GA, USA
| | - Meghan E McGee-Lawrence
- Department of Cellular Biology and Anatomy, Augusta University, Augusta, GA, USA.,Department of Orthopaedic Surgery, Augusta University, Augusta, GA, USA
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Ma M, Feng Z, Liu X, Jia G, Geng B, Xia Y. The Saturation Effect of Body Mass Index on Bone Mineral Density for People Over 50 Years Old: A Cross-Sectional Study of the US Population. Front Nutr 2021; 8:763677. [PMID: 34722617 PMCID: PMC8554069 DOI: 10.3389/fnut.2021.763677] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2021] [Accepted: 09/20/2021] [Indexed: 12/26/2022] Open
Abstract
Background: Previous studies had revealed that Body Mass Index (BMI) positively affected Bone Mineral Density (BMD). However, an excessively high BMI was detrimental to health, especially for the elderly. Moreover, it was elusive how much BMI was most beneficial for BMD in older adults to maintain. Objective: To investigate whether there was a BMI saturation effect value that existed to maintain optimal BMD. Methods: A cross-sectional study was conducted using the datasets of the National Health and Nutrition Examination Survey (NHANES) 2005–2006, 2007–2008, 2009–2010, 2013–2014, and 2017–2018. After adjusting for covariates, an analysis of the association between BMI and BMD in different femoral regions (Total femur, Femoral neck, Trochanter, Intertrochanter, and Ward's triangle) and lumbar spine regions (Total spine, L1, L2, L3, and L4) in the whole population was performed using the multivariate linear regression models, smoothing curve fitting, and saturation effects analysis models. Then, subgroup analyses were performed according to gender, age, and race. Results: A total of 10,910 participants (5,654 males and 5,256 females) over 50 years were enrolled in this population-based study. Multivariate linear regression analyses in the population older than 50 years showed that BMI was positively associated with femoral BMD and lumbar spine BMD (P < 0.001, respectively). Smoothing curve fitting showed that the relationship between BMI and BMD was not simply linear and that a saturation value existed. The saturation effect analysis showed that the BMI saturation value was 26.13 (kg/m2) in the total femur, 26.82 (kg/m2) in the total spine, and showed site-specificity in L1 (31.90 kg/m2) and L2 (30.89 kg/m2). The saturation values were consistent with the whole participants in males, while there was high variability in the females. BMI saturation values remained present in subgroup analyses by age and race, showing specificity in some age (60–70 years old) groups and in some races. Conclusions: Our study showed a saturation value association between BMI and BMD for people over 50 years old. Keeping the BMI in the slightly overweight value (around 26 kg/m2) might reduce other adverse effects while obtaining optimal BMD.
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Affiliation(s)
- Ming Ma
- The Second School of Clinical Medical, Lanzhou University, Lanzhou, China.,Orthopaedics Key Laboratory of Gansu Province, Lanzhou, China.,Department of Orthopaedics, Lanzhou University Second Hospital, Lanzhou, China
| | - Zhiwei Feng
- The Second School of Clinical Medical, Lanzhou University, Lanzhou, China.,Orthopaedics Key Laboratory of Gansu Province, Lanzhou, China
| | - Xiaolong Liu
- The Second School of Clinical Medical, Lanzhou University, Lanzhou, China.,Orthopaedics Key Laboratory of Gansu Province, Lanzhou, China
| | - Gengxin Jia
- The Second School of Clinical Medical, Lanzhou University, Lanzhou, China.,Orthopaedics Key Laboratory of Gansu Province, Lanzhou, China
| | - Bin Geng
- Orthopaedics Key Laboratory of Gansu Province, Lanzhou, China.,Department of Orthopaedics, Lanzhou University Second Hospital, Lanzhou, China
| | - Yayi Xia
- Orthopaedics Key Laboratory of Gansu Province, Lanzhou, China.,Department of Orthopaedics, Lanzhou University Second Hospital, Lanzhou, China
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Yan L, Nielsen FH, Sundaram S, Cao J. Voluntary running of defined distances alters bone microstructure in C57BL/6 mice fed a high-fat diet. Appl Physiol Nutr Metab 2021; 46:1337-1344. [PMID: 34000207 DOI: 10.1139/apnm-2021-0061] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Obesity increases the risk for pathological conditions such as bone loss. On the other hand, physical exercise reduces body adiposity. To test the hypothesis that physical activity improves bone quality, we evaluated voluntary running of defined distances on trabecular and cortical microstructure in mice fed a high-fat diet (HFD). Sedentary mice were fed the standard AIN93G diet or the HFD. Mice fed the HFD remained sedentary or were assigned to unrestricted running or 75%, 50%, and 25% of unrestricted running with an average running activity at 8.3, 6.3, 4.2, and 2.1 km per day, respectively. The bone structural differences found in sedentary mice were that HFD, compared with the AIN93G diet, resulted in a lower bone volume fraction (BV/TV) and a higher structure model index (SMI) in vertebrae. Running had a greater effect on trabecular microstructure in femurs than in vertebrae; the decrease in SMI and an increase in trabecular thickness (Tb.Th) were in dose-dependent manners. Running was positively correlated with BV/TV and Tb.Th and inversely correlated with SMI in femurs. The HFD increased plasma concentrations of tartrate-resistant acid phosphatase 5b, a marker of bone resorption, in sedentary mice, while running decreased it in a dose-dependent manner. The findings show that voluntary running improves bone quality in young adult mice fed an HFD. Novelty: The high-fat diet alters bone microstructure by increasing bone resorption. Quantitative voluntary running improves bone microstructure through its attenuation of bone resorption in mice fed a high-fat diet.
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Affiliation(s)
- Lin Yan
- U.S. Department of Agriculture, Agricultural Research Service, Grand Forks Human Nutrition Research Center, Grand Forks, ND 58202, USA
- U.S. Department of Agriculture, Agricultural Research Service, Grand Forks Human Nutrition Research Center, Grand Forks, ND 58202, USA
| | - Forrest H Nielsen
- U.S. Department of Agriculture, Agricultural Research Service, Grand Forks Human Nutrition Research Center, Grand Forks, ND 58202, USA
- U.S. Department of Agriculture, Agricultural Research Service, Grand Forks Human Nutrition Research Center, Grand Forks, ND 58202, USA
| | - Sneha Sundaram
- U.S. Department of Agriculture, Agricultural Research Service, Grand Forks Human Nutrition Research Center, Grand Forks, ND 58202, USA
- U.S. Department of Agriculture, Agricultural Research Service, Grand Forks Human Nutrition Research Center, Grand Forks, ND 58202, USA
| | - Jay Cao
- U.S. Department of Agriculture, Agricultural Research Service, Grand Forks Human Nutrition Research Center, Grand Forks, ND 58202, USA
- U.S. Department of Agriculture, Agricultural Research Service, Grand Forks Human Nutrition Research Center, Grand Forks, ND 58202, USA
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8
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Alder KD, White AH, Chung YH, Lee I, Back J, Kwon HK, Cahill SV, Hao Z, Li L, Chen F, Lee S, Riedel MD, Lee FY. Systemic Parathyroid Hormone Enhances Fracture Healing in Multiple Murine Models of Type 2 Diabetes Mellitus. JBMR Plus 2020; 4:e10359. [PMID: 32382692 PMCID: PMC7202418 DOI: 10.1002/jbm4.10359] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/03/2020] [Revised: 02/28/2020] [Accepted: 03/07/2020] [Indexed: 12/30/2022] Open
Abstract
Type 2 diabetes mellitus (T2DM) is a multisystemic disease that afflicts more than 415 million people globally-the incidence and prevalence of T2DM continues to rise. It is well-known that T2DM has detrimental effects on bone quality that increase skeletal fragility, which predisposes subjects to an increased risk of fracture and fracture healing that results in non- or malunion. Diabetics have been found to have perturbations in metabolism, hormone production, and calcium homeostasis-particularly PTH expression-that contribute to the increased risk of fracture and decreased fracture healing. Given the perturbations in PTH expression and the establishment of hPTH (1-34) for use in age-related osteoporosis, it was determined logical to attempt to ameliorate the bone phenotype found in T2DM using hPTH (1-34). Therefore, the present study had two aims: (i) to establish a suitable murine model of the skeletal fragility present in T2DM because no current consensus model exists; and (ii) to determine the effects of hPTH (1-34) on bone fractures in T2DM. The results of the present study suggest that the polygenic mouse of T2DM, TALLYHO/JngJ, most accurately recapitulates the diabetic osteoporotic phenotype seen in humans and that the intermittent systemic administration of hPTH (1-34) increases fracture healing in T2DM murine models by increasing the proliferation of mesenchymal stem cells. © 2020 The Authors. JBMR Plus published by Wiley Periodicals, Inc. on behalf of American Society for Bone and Mineral Research.
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Affiliation(s)
- Kareme D Alder
- Department of Orthopædics & Rehabilitation Yale University, School of Medicine New Haven CT USA
| | - Andrew Ha White
- Department of Orthopædics & Rehabilitation Yale University, School of Medicine New Haven CT USA
| | - Yeon-Ho Chung
- Department of Orthopædics & Rehabilitation Yale University, School of Medicine New Haven CT USA
| | - Inkyu Lee
- Department of Orthopædics & Rehabilitation Yale University, School of Medicine New Haven CT USA.,Department of Life Science Chung-Ang University Seoul Republic of Korea
| | - JungHo Back
- Department of Orthopædics & Rehabilitation Yale University, School of Medicine New Haven CT USA
| | - Hyuk-Kwon Kwon
- Department of Orthopædics & Rehabilitation Yale University, School of Medicine New Haven CT USA
| | - Sean V Cahill
- Department of Orthopædics & Rehabilitation Yale University, School of Medicine New Haven CT USA
| | - Zichen Hao
- Department of Orthopædics & Rehabilitation Yale University, School of Medicine New Haven CT USA
| | - Lu Li
- Department of Orthopædics & Rehabilitation Yale University, School of Medicine New Haven CT USA
| | - Fancheng Chen
- Department of Orthopædics & Rehabilitation Yale University, School of Medicine New Haven CT USA
| | - Saelim Lee
- Department of Orthopædics & Rehabilitation Yale University, School of Medicine New Haven CT USA
| | - Matthew D Riedel
- Department of Orthopædics & Rehabilitation Yale University, School of Medicine New Haven CT USA
| | - Francis Y Lee
- Department of Orthopædics & Rehabilitation Yale University, School of Medicine New Haven CT USA
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9
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Jafri L, Majid H, Ahmed S, Naureen G, Khan AH. Calcaneal Ultrasound and Its Relation to Dietary and Lifestyle Factors, Anthropometry, and Vitamin D Deficiency in Young Medical Students. Front Endocrinol (Lausanne) 2020; 11:601562. [PMID: 33551995 PMCID: PMC7859491 DOI: 10.3389/fendo.2020.601562] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/01/2020] [Accepted: 11/26/2020] [Indexed: 11/24/2022] Open
Abstract
BACKGROUND Bone quality and peak bone mass are greatly affected by lifestyle factors. The objective of the study was to investigate the relationships between anthropometry, dietary and caloric intake, body composition measurements, physical activity, and vitamin D status with quantitative ultrasound-based bone parameters among medical students. METHODS Both male and female medical college students were included in this study. A detailed questionnaire was administered, collecting clinical, dietary, physical activity information, physical examination details, including body mass index (BMI). Body composition (total body fat, total body water, muscle mass, mean visceral fat mass, basal metabolic rate, bone mass using a bioelectrical impedance analyzer) and calcaneal heel ultrasound parameters were measured using an Osteosys Sonost-3000, Ultrasound Bone Densitometer were measured, respectively. RESULTS In this cross-sectional study, 211 healthy students with a mean age of 20.1 ± 1.1 years, 51.7% (n = 109) were males. Majority (79.4%) of the young adults had vitamin D deficiency. The mean BMI, calcium intake, and vitamin D levels were 22.35 ± 3.43 kg/m2, 788.7 ± 364.8 mg/day, and 15.02 ± 8.63 ng/ml, respectively. Female subjects compared to males had statistically significantly lower daily energy intake, muscle mass, visceral fat mass, calcium intake, and vitamin D levels. In addition the median Z-scores in females [-1.40 (-0.57 to -1.82)] was significantly poorer than the male [-0.50 (0.20 to -1.3)] counterparts, p-value <0.001. Multiple regression analysis showed that overall body fat percent (p-value 0.016) and visceral fat percent (p-value 0.029) were the only significant negative predictors to the calcaneal bone quality index (BQI) values. CONCLUSION Adolescent lifestyle patterns can influence young adult bone strength. The young Pakistani females exhibited significantly lower dietary intakes and more inadequate bone parameters compared to males. Our data suggest that total body and visceral fat percent are the predominant negatively associated determinant of bone strength for this cohort. Calcaneal ultrasound can be utilized for mass screening of young adults for identification of low BMD.
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Affiliation(s)
- Lena Jafri
- Section of Chemical Pathology, Department of Pathology and Laboratory Medicine, Aga Khan University, Karachi, Pakistan
- *Correspondence: Lena Jafri,
| | - Hafsa Majid
- Section of Chemical Pathology, Department of Pathology and Laboratory Medicine, Aga Khan University, Karachi, Pakistan
| | - Sibtain Ahmed
- Section of Chemical Pathology, Department of Pathology and Laboratory Medicine, Aga Khan University, Karachi, Pakistan
| | - Ghazala Naureen
- Department of Medicine - Western Health, The University of Melbourne and Australian Institute for Musculoskeletal Science, The University of Melbourne and Western Health, St Albans, VIC, Australia
| | - Aysha Habib Khan
- Section of Chemical Pathology, Department of Pathology and Laboratory Medicine, Aga Khan University, Karachi, Pakistan
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Keune JA, Branscum AJ, Wong CP, Iwaniec UT, Turner RT. Effect of Leptin Deficiency on the Skeletal Response to Hindlimb Unloading in Adult Male Mice. Sci Rep 2019; 9:9336. [PMID: 31249331 PMCID: PMC6597714 DOI: 10.1038/s41598-019-45587-0] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2018] [Accepted: 06/06/2019] [Indexed: 12/29/2022] Open
Abstract
Based on body weight, morbidly obese leptin-deficient ob/ob mice have less bone than expected, suggesting that leptin plays a role in the skeletal response to weight bearing. To evaluate this possibility, we compared the skeletal response of wild type (WT) and ob/ob mice to hindlimb unloading (HU). Mice were individually housed at 32 °C (thermoneutral) from 4 weeks of age (rapidly growing) to 16 weeks of age (approaching skeletal maturity). Mice were then randomized into one of 4 groups (n = 10/group): (1) WT control, (2) WT HU, (3) ob/ob control, and (4) ob/ob HU and the results analyzed by 2-way ANOVA. ob/ob mice pair-fed to WT mice had normal cancellous bone volume fraction (BV/TV) in distal femur, lower femur length and total bone area, mineral content (BMC) and density (BMD), and higher cancellous bone volume fraction in lumbar vertebra (LV). HU resulted in lower BMC and BMD in total femur, and lower BV/TV in distal femur and LV in both genotypes. Cancellous bone loss in femur in both genotypes was associated with increases in osteoclast-lined bone perimeter. In summary, leptin deficiency did not attenuate HU-induced osteopenia in male mice, suggesting that leptin is not required for bone loss induced by unweighting.
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Affiliation(s)
- Jessica A. Keune
- 0000 0001 2112 1969grid.4391.fSkeletal Biology Laboratory, School of Biological and Population Health Sciences, Oregon State University, Corvallis, OR 97331 USA
| | - Adam J. Branscum
- 0000 0001 2112 1969grid.4391.fBiostatistics Program, School of Biological and Population Health Sciences, Oregon State University, Corvallis, OR 97331 USA
| | - Carmen P. Wong
- 0000 0001 2112 1969grid.4391.fSkeletal Biology Laboratory, School of Biological and Population Health Sciences, Oregon State University, Corvallis, OR 97331 USA
| | - Urszula T. Iwaniec
- 0000 0001 2112 1969grid.4391.fSkeletal Biology Laboratory, School of Biological and Population Health Sciences, Oregon State University, Corvallis, OR 97331 USA ,0000 0001 2112 1969grid.4391.fCenter for Healthy Aging Research, Oregon State University, Corvallis, OR 97331 USA
| | - Russell T. Turner
- 0000 0001 2112 1969grid.4391.fSkeletal Biology Laboratory, School of Biological and Population Health Sciences, Oregon State University, Corvallis, OR 97331 USA ,0000 0001 2112 1969grid.4391.fCenter for Healthy Aging Research, Oregon State University, Corvallis, OR 97331 USA
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11
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Reid IR, Baldock PA, Cornish J. Effects of Leptin on the Skeleton. Endocr Rev 2018; 39:938-959. [PMID: 30184053 DOI: 10.1210/er.2017-00226] [Citation(s) in RCA: 102] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/11/2017] [Accepted: 06/26/2018] [Indexed: 12/12/2022]
Abstract
Leptin originates in adipocytes, including those in bone marrow, and circulates in concentrations 20 to 90 times higher than those in the cerebrospinal fluid. It has direct anabolic effects on osteoblasts and chondrocytes, but it also influences bone indirectly, via the hypothalamus and sympathetic nervous system, via changes in body weight, and via effects on the production of other hormones (e.g., pituitary). Leptin's role in bone physiology is determined by the balance of these conflicting effects. Reflecting this inconsistency, the leptin-deficient mouse has reduced length and bone mineral content of long bones but increased vertebral trabecular bone. A consistent bone phenotype in human leptin deficiency has not been established. Systemic leptin administration in animals and humans usually exerts a positive effect on bone mass, and leptin administration into the cerebral ventricles usually normalizes the bone phenotype in leptin-deficient mice. Reflecting the role of the sympathetic nervous system in mediating the central catabolic effects of leptin on the skeleton, β-adrenergic agonists and antagonists have major effects on bone in mice, but this is not consistently seen in humans. The balance of the central and peripheral effects of leptin on bone remains an area of substantial controversy and might vary between species and according to other factors such as body weight, baseline circulating leptin levels, and the presence of specific pathologies. In humans, leptin is likely to contribute to the positive relationship observed between adiposity and bone density, which allows the skeleton to respond appropriately to changes in soft tissue mass.
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Affiliation(s)
- Ian R Reid
- University of Auckland, Auckland, New Zealand.,Department of Endocrinology, Auckland District Health Board, Auckland, New Zealand
| | - Paul A Baldock
- Garvan Institute of Medical Research, Sydney, New South Wales, Australia
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12
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Han Y, Xu G, Zhang J, Yan M, Li X, Ma B, Jun L, Wang SJ, Tan J. Leptin induces osteocalcin expression in ATDC5 cells through activation of the MAPK-ERK1/2 signaling pathway. Oncotarget 2018; 7:64021-64029. [PMID: 27564111 PMCID: PMC5325422 DOI: 10.18632/oncotarget.11578] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2016] [Accepted: 08/11/2016] [Indexed: 11/25/2022] Open
Abstract
Both leptin and osteocalcin have been found to affect growth-plate cartilage development through regulation of the physiologic processes of endochondral bone formation. Leptin mediates bone development and osteocalcin secreted in the late stage of osteoblast differentiation. The relationship between leptin and osteocalcin expression in the chondrogenic cells line is still not clear. Thus, the aim of this study was to explore the effect of leptin on the expression of osteocalcin in chondrocytes. We used clonal mouse chondrogenic ATDC5 cells to investigate the relationship between leptin and osteocalcin. We found that both leptin and osteocalcin expression were dynamically expressed during ATDC5 cell differentiation from 4 to 21 days. We also found that leptin significantly upregulated osteocalcin mRNA and protein levels 24 h after leptin stimulation. However, different concentrations and exposure times of osteocalcin did not affect the levels of leptin protein. Furthermore, we confirmed that leptin augmented the phosphorylation of extracellular signal-regulated kinase 1/2 (ERK1/2) in a time-dependent manner but not p38 or AKT. Inhibition of pERK1/2 expression by a specific ERK1/2 inhibitor U0126 and a special small interfering RNA attenuated levels of leptin-induced osteocalcin expression, indicating that ERK1/2 mediates, in part, the effects of leptin on osteocalcin. Taken together, our results suggest that leptin regulates the expression of osteocalcin in growth plate chondrocytes via the ERK1/2 signaling pathway, while there is no effect on the phosphorylation of either p38 or AKT.
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Affiliation(s)
- Yingchao Han
- Department of Spine Surgery, Shanghai East Hospital, Tongji University, School of Medicine, Shanghai, 200120, China
| | - Guanghui Xu
- Department of Orthopedics, Shanghai Zhabei District Central hospital, Zhonghuaxin Road Zhabei District, Shanghai, 200070, China
| | - Jingjie Zhang
- Department of Spine Surgery, Shanghai East Hospital, Tongji University, School of Medicine, Shanghai, 200120, China
| | - Meijun Yan
- Department of Spine Surgery, Shanghai East Hospital, Tongji University, School of Medicine, Shanghai, 200120, China
| | - Xinhua Li
- Department of Spine Surgery, Shanghai East Hospital, Tongji University, School of Medicine, Shanghai, 200120, China
| | - Bin Ma
- Department of Spine Surgery, Shanghai East Hospital, Tongji University, School of Medicine, Shanghai, 200120, China
| | - Lili Jun
- Department of Spine Surgery, Shanghai East Hospital, Tongji University, School of Medicine, Shanghai, 200120, China
| | - Shan-Jin Wang
- Department of Spine Surgery, Shanghai East Hospital, Tongji University, School of Medicine, Shanghai, 200120, China
| | - Jun Tan
- Department of Spine Surgery, Shanghai East Hospital, Tongji University, School of Medicine, Shanghai, 200120, China
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13
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14
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Philbrick KA, Martin SA, Colagiovanni AR, Branscum AJ, Turner RT, Iwaniec UT. Effects of hypothalamic leptin gene therapy on osteopetrosis in leptin-deficient mice. J Endocrinol 2018; 236:57-68. [PMID: 29191939 PMCID: PMC5771473 DOI: 10.1530/joe-17-0524] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/04/2017] [Accepted: 11/20/2017] [Indexed: 12/26/2022]
Abstract
Impaired resorption of cartilage matrix deposited during endochondral ossification is a defining feature of juvenile osteopetrosis. Growing, leptin-deficient ob/ob mice exhibit a mild form of osteopetrosis. However, the extent to which the disease is (1) self-limiting and (2) reversible by leptin treatment is unknown. We addressed the first question by performing histomorphometric analysis of femurs in rapidly growing (2-month-old), slowly growing (4-month-old) and skeletally mature (6-month-old) wild-type (WT) and ob/ob male mice. Absent by 6 months of age in WT mice, cartilage matrix persisted to varying extents in distal femur epiphysis, metaphysis and diaphysis in ob/ob mice, suggesting that the osteopetrotic phenotype is not entirely self-limiting. To address the second question, we employed hypothalamic recombinant adeno-associated virus (rAAV) gene therapy to restore leptin signaling in ob/ob mice. Two-month-old mice were randomized to one of the three groups: (1) untreated control, (2) rAAV-Leptin or (3) control vector rAAV-green fluorescent protein and vectors injected intracerebroventricularly. Seven months later, rAAV-leptin-treated mice exhibited no cartilage in the metaphysis and greatly reduced cartilage in the epiphysis and diaphysis. At the cellular level, the reduction in cartilage was associated with increased bone turnover. These findings (1) support the concept that leptin is important for normal replacement of cartilage by bone, and (2) demonstrate that osteopetrosis in ob/ob mice is bone-compartment-specific and reversible by leptin at skeletal sites capable of undergoing robust bone turnover.
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Affiliation(s)
- Kenneth A Philbrick
- Skeletal Biology LaboratorySchool of Biological and Population Health Sciences, Oregon State University, Corvallis, Oregon, USA
| | - Stephen A Martin
- Skeletal Biology LaboratorySchool of Biological and Population Health Sciences, Oregon State University, Corvallis, Oregon, USA
| | - Amy R Colagiovanni
- Skeletal Biology LaboratorySchool of Biological and Population Health Sciences, Oregon State University, Corvallis, Oregon, USA
| | - Adam J Branscum
- Biostatistics ProgramSchool of Biological and Population Health Sciences, Oregon State University, Corvallis, Oregon, USA
| | - Russell T Turner
- Skeletal Biology LaboratorySchool of Biological and Population Health Sciences, Oregon State University, Corvallis, Oregon, USA
- Center for Healthy Aging ResearchOregon State University, Corvallis, Oregon, USA
| | - Urszula T Iwaniec
- Skeletal Biology LaboratorySchool of Biological and Population Health Sciences, Oregon State University, Corvallis, Oregon, USA
- Center for Healthy Aging ResearchOregon State University, Corvallis, Oregon, USA
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15
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Wang T, Zhu X, Dai F, Li C, Huang D, Fang Z, Zhang Q, Lu Y. Effects of a standard high-fat diet with or without multiple deficiencies on bone parameters in ovariectomized mature rat. PLoS One 2017; 12:e0184983. [PMID: 28950016 PMCID: PMC5614430 DOI: 10.1371/journal.pone.0184983] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2017] [Accepted: 09/04/2017] [Indexed: 01/11/2023] Open
Abstract
The aim of this study was to determine the effects of a standard high fat diet (D12451) with or without vitamin D3, phosphorus, and calcium (i.e., high-fat diet [HFD] or high-fat deficient diet [HFDD]) on the bone parameters of ovariectomized female rats. Six-month-old of female Sprauge Dawley (SD) rats were randomly divided into six study groups: sham operation with standard chow diet (SSCD), sham operation with a HFD (SHFD), sham operation with a HFDD (SHFDD), ovariectomized (OVX), OVX with a HFD (OVX-HFD), and OVX with a HFDD (OVX-HFDD). A bilateral ovariectomy was administered to the OVX, OVX-HFD, and OVX-HFDD rats, while the SSCD, SHFD, and SHFDD rats were only given a laparotomy. Multiple analyses concerning the glucose and insulin tolerance, structure, bone strength, bone matrix, and mineralization of the rats were conducted in order to produce a detailed characterization of the effects of a HFD and a HFDD on postmenopausal osteoporotic rats. Seven months of HFD and HFDD feeding resulted in obesity and insulin resistance in female SD rats. A standard HFD increased the bone calcium content and bone strength of OVX rats. Conversely, the serum N-mid osteocalcin (N-MID-OT) and tartrate-resistant acid phosphatase (TRAP) levels in the OVX-HFDD group were increased, accompanied by a clear decrease in the bone mineral density (BMD), bone mineral content (BMC), bone calcium and bone strength, as well as reduced osteocalcin expression. A HFDD weakened the activity of the osteoblasts while aggravating bone loss and decreasing bone strength in ovariectomized rats, which may be due to the calcium, phosphorus and vitamin D3 deficiencies in the diet.
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Affiliation(s)
- Ting Wang
- Department of Endocrinology, The First Affiliated Hospital of Anhui Medical University, Hefei, Anhui, People’s Republic of China
| | - Xiaohuan Zhu
- Department of Endocrinology, The First Affiliated Hospital of Anhui Medical University, Hefei, Anhui, People’s Republic of China
| | - Fang Dai
- Department of Endocrinology, The First Affiliated Hospital of Anhui Medical University, Hefei, Anhui, People’s Republic of China
| | - Chaofei Li
- Department of Biochemistry and Molecular Biology, College of Basic Medicine, Anhui Medical University, Hefei, Anhui, People’s Republic of China
| | - Dake Huang
- The Comprehensive Laboratory, College of Basic Medicine, Anhui Medical University, Hefei, Anhui, People’s Republic of China
| | - Zhaohui Fang
- Department of Endocrinology, The First Affilliated Hospital of Anhui University of Traditional Chinese Medicine, Hefei, Anhui, People’s Republic of China
| | - Qiu Zhang
- Department of Endocrinology, The First Affiliated Hospital of Anhui Medical University, Hefei, Anhui, People’s Republic of China
- * E-mail: (QZ); (YL)
| | - Yunxia Lu
- Department of Biochemistry and Molecular Biology, College of Basic Medicine, Anhui Medical University, Hefei, Anhui, People’s Republic of China
- The Comprehensive Laboratory, College of Basic Medicine, Anhui Medical University, Hefei, Anhui, People’s Republic of China
- * E-mail: (QZ); (YL)
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Philbrick KA, Wong CP, Branscum AJ, Turner RT, Iwaniec UT. Leptin stimulates bone formation in ob/ob mice at doses having minimal impact on energy metabolism. J Endocrinol 2017; 232:461-474. [PMID: 28057869 PMCID: PMC5288125 DOI: 10.1530/joe-16-0484] [Citation(s) in RCA: 53] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/02/2016] [Accepted: 01/05/2017] [Indexed: 01/08/2023]
Abstract
Leptin, the protein product of the ob gene, is essential for normal bone growth, maturation and turnover. Peripheral actions of leptin occur at lower serum levels of the hormone than central actions because entry of leptin into the central nervous system (CNS) is limited due to its saturable transport across the blood-brain barrier (BBB). We performed a study in mice to model the impact of leptin production associated with different levels of adiposity on bone formation and compared the response with well-established centrally mediated actions of the hormone on energy metabolism. Leptin was infused (0, 4, 12, 40, 140 or 400 ng/h) for 12 days into 6-week-old female ob/ob mice (n = 8/group) using sc-implanted osmotic pumps. Treatment resulted in a dose-associated increase in serum leptin. Bone formation parameters were increased at EC50 infusion rates of 7-17 ng/h, whereas higher levels (EC50, 40-80 ng/h) were required to similarly influence indices of energy metabolism. We then analyzed gene expression in tibia and hypothalamus at dose rates of 0, 12 and 140 ng/h; the latter dose resulted in serum leptin levels similar to WT mice. Infusion with 12 ng/h leptin increased the expression of genes associated with Jak/Stat signaling and bone formation in tibia with minimal effect on Jak/Stat signaling and neurotransmitters in hypothalamus. The results suggest that leptin acts peripherally to couple bone acquisition to energy availability and that limited transport across the BBB insures that the growth-promoting actions of peripheral leptin are not curtailed by the hormone's CNS-mediated anorexigenic actions.
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Affiliation(s)
- Kenneth A Philbrick
- Skeletal Biology LaboratorySchool of Biological and Population Health Sciences, Oregon State University, Corvallis, Oregon, USA
| | - Carmen P Wong
- Skeletal Biology LaboratorySchool of Biological and Population Health Sciences, Oregon State University, Corvallis, Oregon, USA
| | - Adam J Branscum
- Biostatistics ProgramSchool of Biological and Population Health Sciences, Oregon State University, Corvallis, Oregon, USA
| | - Russell T Turner
- Skeletal Biology LaboratorySchool of Biological and Population Health Sciences, Oregon State University, Corvallis, Oregon, USA
- Center for Healthy Aging ResearchOregon State University, Corvallis, Oregon, USA
| | - Urszula T Iwaniec
- Skeletal Biology LaboratorySchool of Biological and Population Health Sciences, Oregon State University, Corvallis, Oregon, USA
- Center for Healthy Aging ResearchOregon State University, Corvallis, Oregon, USA
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17
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Rezende Yanagihara G, Carminati Shimano R, Atsuko Tida J, Suzuki Yamanaka J, Yasuyo Fukada S, Mardegan Issa JP, Shimano AC, Tavares JM. Influence of High-Fat Diet on Bone Tissue: An Experimental Study in Growing Rats. J Nutr Health Aging 2017; 21:1337-1343. [PMID: 29188898 DOI: 10.1007/s12603-017-0871-x] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
BACKGROUND The relationship between obesity and bone tissue remains contradictory, especially when the effect of high-fat diet is assessed in experimental models. The aim of this study was to evaluate the effects of high-fat diet on bone metabolism of growing rats. METHODS Twenty weaned female Wistar rats were equally divided into two groups: SD (standard diet) and HFD (high-fat diet with 60 % of energy as fat). After five weeks of the two diets, the rats were euthanized, and the liver, blood and bones extracted. The liver was analysed for malondialdehyde (MDA) and reduced glutathione (GSH) concentrations. Blood was analysed by the ELISA method for osteoprotegerin (OPG) and tumour necrosis factor ligand superfamily member 11 (TNFSF11/RANKL). The bone tissue was analysed by dual-energy X-ray absorptiometry (DXA), mechanical tests, computed microtomography, histological quantitative analysis and scanning electron microscopy. The gene expressions of PPAR-γ Runx-2, RANKL and Cathepsin-K were also evaluated. RESULTS HFD caused an increase in the MDA concentration, indicating oxidative stress. It also increased the expression of PPAR-γ, which is the gene that is related to adipocyte differentiation. There was an increase in BMD of the tibia of animals fed with the HFD, but other microstructural and mechanical properties were maintained unaltered. In addition, there were no changes in the gene expressions related to the differentiation of osteoblasts and osteoclasts, as well as no changes to the biochemical markers of bone formation and bone resorption. CONCLUSION Liver and gene parameters are changed in response to the HFD. However, although there was an increase in BMD, the microstructure and function of the bone did not change after a 5-week HFD.
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Affiliation(s)
- G Rezende Yanagihara
- Prof. João Manuel R. S. Tavares, Faculdade de Engenharia da Universidade do Porto, Rua Dr. Roberto Frias, s/n, 4200-465 Porto, Portugal, , Phone: +351 22 5081487, Fax: +351 22 5081445, url: www.fe.up.pt/~tavares
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18
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Iwaniec UT, Turner RT. Influence of body weight on bone mass, architecture and turnover. J Endocrinol 2016; 230:R115-30. [PMID: 27352896 PMCID: PMC4980254 DOI: 10.1530/joe-16-0089] [Citation(s) in RCA: 108] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/22/2016] [Accepted: 06/27/2016] [Indexed: 12/11/2022]
Abstract
Weight-dependent loading of the skeleton plays an important role in establishing and maintaining bone mass and strength. This review focuses on mechanical signaling induced by body weight as an essential mechanism for maintaining bone health. In addition, the skeletal effects of deviation from normal weight are discussed. The magnitude of mechanical strain experienced by bone during normal activities is remarkably similar among vertebrates, regardless of size, supporting the existence of a conserved regulatory mechanism, or mechanostat, that senses mechanical strain. The mechanostat functions as an adaptive mechanism to optimize bone mass and architecture based on prevailing mechanical strain. Changes in weight, due to altered mass, weightlessness (spaceflight), and hypergravity (modeled by centrifugation), induce an adaptive skeletal response. However, the precise mechanisms governing the skeletal response are incompletely understood. Furthermore, establishing whether the adaptive response maintains the mechanical competence of the skeleton has proven difficult, necessitating the development of surrogate measures of bone quality. The mechanostat is influenced by regulatory inputs to facilitate non-mechanical functions of the skeleton, such as mineral homeostasis, as well as hormones and energy/nutrient availability that support bone metabolism. Although the skeleton is very capable of adapting to changes in weight, the mechanostat has limits. At the limits, extreme deviations from normal weight and body composition are associated with impaired optimization of bone strength to prevailing body size.
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Affiliation(s)
- Urszula T Iwaniec
- Skeletal Biology LaboratorySchool of Biological and Population Health Sciences, Oregon State University, Corvallis, Oregon, USA Center for Healthy Aging ResearchOregon State University, Corvallis, Oregon, USA
| | - Russell T Turner
- Skeletal Biology LaboratorySchool of Biological and Population Health Sciences, Oregon State University, Corvallis, Oregon, USA Center for Healthy Aging ResearchOregon State University, Corvallis, Oregon, USA
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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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Macedo AP, Shimano RC, Ferrari DT, Issa JPM, Jordão AA, Shimano AC. Influence of treadmill training on bone structure under osteometabolic alteration in rats subjected to high-fat diet. Scand J Med Sci Sports 2016; 27:167-176. [PMID: 26923426 DOI: 10.1111/sms.12650] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/04/2016] [Indexed: 01/02/2023]
Abstract
Nutrition and physical training have important roles in the accumulation and maintenance of bone mass. The aim of this study was to evaluate, in ovariectomized rats (OVX), the effects of treadmill training (T) with high-fat diet (F) on weight gain and bone tissue properties with eight groups (n = 10) for 12 weeks: OVX SC (OVX, sedentary lifestyle, diet control); OVX SF; OVX TC; OVX TF; SH SC (SHAM, sedentary lifestyle, diet control); SH SF; SH TC; and SH TF. Weekly weight gain and final body composition were assessed. After euthanasia, tibiae were analyzed. The trained animals had higher body weight (P = 0.001), bone mineral density (P < 0.001), and trabecular bone (P < 0.001). The animals with a high-fat diet showed higher global fat (P < 0.001), percentage of global fat (P < 0.001) and deformation at impact (P = 0.031) and reduced tibial bone mineral content (P = 0.036). Physical training improves bone microarchitecture, without presenting an increase in impact resistance, and a high-fat diet increases body fat and impairs bone mineralization.
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Affiliation(s)
- A P Macedo
- Bioengineering Laboratory, Department of Biomechanics, Medicine and Rehabilitation of the Locomotor System, Ribeirão Preto Medical School, University of São Paulo, São Paulo, Brazil
| | - R C Shimano
- Bioengineering Laboratory, Department of Biomechanics, Medicine and Rehabilitation of the Locomotor System, Ribeirão Preto Medical School, University of São Paulo, São Paulo, Brazil
| | - D T Ferrari
- Bioengineering Laboratory, Department of Biomechanics, Medicine and Rehabilitation of the Locomotor System, Ribeirão Preto Medical School, University of São Paulo, São Paulo, Brazil
| | - J P M Issa
- Department of Morphology, Physiology and Basic Pathology, School of Dentistry of Ribeirão Preto, University of São Paulo, São Paulo, Brazil
| | - A A Jordão
- Department of Internal Medicine, Ribeirão Preto Medical School, University of São Paulo, São Paulo, Brazil
| | - A C Shimano
- Bioengineering Laboratory, Department of Biomechanics, Medicine and Rehabilitation of the Locomotor System, Ribeirão Preto Medical School, University of São Paulo, São Paulo, Brazil
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21
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Lindenmaier LB, Philbrick KA, Branscum AJ, Kalra SP, Turner RT, Iwaniec UT. Hypothalamic Leptin Gene Therapy Reduces Bone Marrow Adiposity in ob/ob Mice Fed Regular and High-Fat Diets. Front Endocrinol (Lausanne) 2016; 7:110. [PMID: 27579023 PMCID: PMC4985531 DOI: 10.3389/fendo.2016.00110] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/19/2016] [Accepted: 08/02/2016] [Indexed: 12/14/2022] Open
Abstract
Low bone mass is often associated with elevated bone marrow adiposity. Since osteoblasts and adipocytes are derived from the same mesenchymal stem cell (MSC) progenitor, adipocyte formation may increase at the expense of osteoblast formation. Leptin is an adipocyte-derived hormone known to regulate energy and bone metabolism. Leptin deficiency and high-fat diet-induced obesity are associated with increased marrow adipose tissue (MAT) and reduced bone formation. Short-duration studies suggest that leptin treatment reduces MAT and increases bone formation in leptin-deficient ob/ob mice fed a regular diet. Here, we determined the long-duration impact of increased hypothalamic leptin on marrow adipocytes and osteoblasts in ob/ob mice following recombinant adeno-associated virus (rAAV) gene therapy. Eight- to 10-week-old male ob/ob mice were randomized into four groups: (1) untreated, (2) rAAV-Lep, (3) rAAV-green fluorescent protein (rAAV-GFP), or (4) pair-fed to rAAV-Lep. For vector administration, mice were injected intracerebroventricularly with either rAAV-leptin gene therapy (rAAV-Lep) or rAAV-GFP (9 × 10(7) particles) and maintained for 30 weeks. In a second study, the impact of increased hypothalamic leptin levels on MAT was determined in mice fed high-fat diets; ob/ob mice were randomized into two groups and treated with either rAAV-Lep or rAAV-GFP. At 7 weeks post-vector administration, half the mice in each group were switched to a high-fat diet for 8 weeks. Wild-type (WT) controls included age-matched mice fed regular or high-fat diet. High-fat diet resulted in a threefold increase in MAT in WT mice, whereas MAT was increased by leptin deficiency up to 50-fold. Hypothalamic leptin gene therapy increased osteoblast perimeter and osteoclast perimeter with minor change in cancellous bone architecture. The gene therapy decreased MAT levels in ob/ob mice fed regular or high-fat diet to values similar to WT mice fed regular diet. These findings suggest that leptin plays an important role in regulating the differentiation of MSCs to adipocytes and osteoblasts, a process that may be dysregulated by high-fat diet. However, the results also illustrate that reducing MAT by increasing leptin levels does not necessarily result in increased bone mass.
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Affiliation(s)
- Laurence B. Lindenmaier
- Skeletal Biology Laboratory, School of Biological and Population Health Sciences, Oregon State University, Corvallis, OR, USA
| | - Kenneth A. Philbrick
- Skeletal Biology Laboratory, School of Biological and Population Health Sciences, Oregon State University, Corvallis, OR, USA
| | - Adam J. Branscum
- Biostatistics Program, School of Biological and Population Health Sciences, Oregon State University, Corvallis, OR, USA
| | - Satya P. Kalra
- Department of Neuroscience, McKnight Brain Institute, University of Florida, Gainesville, FL, USA
| | - Russell T. Turner
- Skeletal Biology Laboratory, School of Biological and Population Health Sciences, Oregon State University, Corvallis, OR, USA
- Center for Healthy Aging Research, Oregon State University, Corvallis, OR, USA
| | - Urszula T. Iwaniec
- Skeletal Biology Laboratory, School of Biological and Population Health Sciences, Oregon State University, Corvallis, OR, USA
- Center for Healthy Aging Research, Oregon State University, Corvallis, OR, USA
- *Correspondence: Urszula T. Iwaniec,
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22
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Turner RT, Dube M, Branscum AJ, Wong CP, Olson DA, Zhong X, Kweh MF, Larkin IV, Wronski TJ, Rosen CJ, Kalra SP, Iwaniec UT. Hypothalamic leptin gene therapy reduces body weight without accelerating age-related bone loss. J Endocrinol 2015; 227:129-41. [PMID: 26487675 PMCID: PMC4917201 DOI: 10.1530/joe-15-0280] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 09/14/2015] [Indexed: 02/04/2023]
Abstract
Excessive weight gain in adults is associated with a variety of negative health outcomes. Unfortunately, dieting, exercise, and pharmacological interventions have had limited long-term success in weight control and can result in detrimental side effects, including accelerating age-related cancellous bone loss. We investigated the efficacy of using hypothalamic leptin gene therapy as an alternative method for reducing weight in skeletally-mature (9 months old) female rats and determined the impact of leptin-induced weight loss on bone mass, density, and microarchitecture, and serum biomarkers of bone turnover (CTx and osteocalcin). Rats were implanted with cannulae in the 3rd ventricle of the hypothalamus and injected with either recombinant adeno-associated virus encoding the gene for rat leptin (rAAV-Leptin, n=7) or a control vector encoding green fluorescent protein (rAAV-GFP, n=10) and sacrificed 18 weeks later. A baseline control group (n=7) was sacrificed at vector administration. rAAV-Leptin-treated rats lost weight (-4±2%) while rAAV-GFP-treated rats gained weight (14±2%) during the study. At study termination, rAAV-Leptin-treated rats weighed 17% less than rAAV-GFP-treated rats and had lower abdominal white adipose tissue weight (-80%), serum leptin (-77%), and serum IGF1 (-34%). Cancellous bone volume fraction in distal femur metaphysis and epiphysis, and in lumbar vertebra tended to be lower (P<0.1) in rAAV-GFP-treated rats (13.5 months old) compared to baseline control rats (9 months old). Significant differences in cancellous bone or biomarkers of bone turnover were not detected between rAAV-Leptin and rAAV-GFP rats. In summary, rAAV-Leptin-treated rats maintained a lower body weight compared to baseline and rAAV-GFP-treated rats with minimal effects on bone mass, density, microarchitecture, or biochemical markers of bone turnover.
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Affiliation(s)
- Russell T Turner
- Skeletal Biology LaboratorySchool of Biological and Population Health Sciences, Oregon State University, Corvallis, Oregon 97331, USACenter for Healthy Aging ResearchOregon State University, Corvallis, Oregon, USADepartment of NeuroscienceMcKnight Brain Institute, University of Florida, Gainesville, Florida, USABiostatisticsSchool of Biological and Population Health Sciences, Oregon State University, Corvallis, Oregon, USADepartment of Physiological SciencesUniversity of Florida, Gainesville, Florida, USADepartment of Large Animal Clinical SciencesUniversity of Florida, Gainesville, Florida, USAMaine Medical Center Research InstituteScarborough, Maine, USA Skeletal Biology LaboratorySchool of Biological and Population Health Sciences, Oregon State University, Corvallis, Oregon 97331, USACenter for Healthy Aging ResearchOregon State University, Corvallis, Oregon, USADepartment of NeuroscienceMcKnight Brain Institute, University of Florida, Gainesville, Florida, USABiostatisticsSchool of Biological and Population Health Sciences, Oregon State University, Corvallis, Oregon, USADepartment of Physiological SciencesUniversity of Florida, Gainesville, Florida, USADepartment of Large Animal Clinical SciencesUniversity of Florida, Gainesville, Florida, USAMaine Medical Center Research InstituteScarborough, Maine, USA
| | - Michael Dube
- Skeletal Biology LaboratorySchool of Biological and Population Health Sciences, Oregon State University, Corvallis, Oregon 97331, USACenter for Healthy Aging ResearchOregon State University, Corvallis, Oregon, USADepartment of NeuroscienceMcKnight Brain Institute, University of Florida, Gainesville, Florida, USABiostatisticsSchool of Biological and Population Health Sciences, Oregon State University, Corvallis, Oregon, USADepartment of Physiological SciencesUniversity of Florida, Gainesville, Florida, USADepartment of Large Animal Clinical SciencesUniversity of Florida, Gainesville, Florida, USAMaine Medical Center Research InstituteScarborough, Maine, USA
| | - Adam J Branscum
- Skeletal Biology LaboratorySchool of Biological and Population Health Sciences, Oregon State University, Corvallis, Oregon 97331, USACenter for Healthy Aging ResearchOregon State University, Corvallis, Oregon, USADepartment of NeuroscienceMcKnight Brain Institute, University of Florida, Gainesville, Florida, USABiostatisticsSchool of Biological and Population Health Sciences, Oregon State University, Corvallis, Oregon, USADepartment of Physiological SciencesUniversity of Florida, Gainesville, Florida, USADepartment of Large Animal Clinical SciencesUniversity of Florida, Gainesville, Florida, USAMaine Medical Center Research InstituteScarborough, Maine, USA
| | - Carmen P Wong
- Skeletal Biology LaboratorySchool of Biological and Population Health Sciences, Oregon State University, Corvallis, Oregon 97331, USACenter for Healthy Aging ResearchOregon State University, Corvallis, Oregon, USADepartment of NeuroscienceMcKnight Brain Institute, University of Florida, Gainesville, Florida, USABiostatisticsSchool of Biological and Population Health Sciences, Oregon State University, Corvallis, Oregon, USADepartment of Physiological SciencesUniversity of Florida, Gainesville, Florida, USADepartment of Large Animal Clinical SciencesUniversity of Florida, Gainesville, Florida, USAMaine Medical Center Research InstituteScarborough, Maine, USA
| | - Dawn A Olson
- Skeletal Biology LaboratorySchool of Biological and Population Health Sciences, Oregon State University, Corvallis, Oregon 97331, USACenter for Healthy Aging ResearchOregon State University, Corvallis, Oregon, USADepartment of NeuroscienceMcKnight Brain Institute, University of Florida, Gainesville, Florida, USABiostatisticsSchool of Biological and Population Health Sciences, Oregon State University, Corvallis, Oregon, USADepartment of Physiological SciencesUniversity of Florida, Gainesville, Florida, USADepartment of Large Animal Clinical SciencesUniversity of Florida, Gainesville, Florida, USAMaine Medical Center Research InstituteScarborough, Maine, USA
| | - Xiaoying Zhong
- Skeletal Biology LaboratorySchool of Biological and Population Health Sciences, Oregon State University, Corvallis, Oregon 97331, USACenter for Healthy Aging ResearchOregon State University, Corvallis, Oregon, USADepartment of NeuroscienceMcKnight Brain Institute, University of Florida, Gainesville, Florida, USABiostatisticsSchool of Biological and Population Health Sciences, Oregon State University, Corvallis, Oregon, USADepartment of Physiological SciencesUniversity of Florida, Gainesville, Florida, USADepartment of Large Animal Clinical SciencesUniversity of Florida, Gainesville, Florida, USAMaine Medical Center Research InstituteScarborough, Maine, USA
| | - Mercedes F Kweh
- Skeletal Biology LaboratorySchool of Biological and Population Health Sciences, Oregon State University, Corvallis, Oregon 97331, USACenter for Healthy Aging ResearchOregon State University, Corvallis, Oregon, USADepartment of NeuroscienceMcKnight Brain Institute, University of Florida, Gainesville, Florida, USABiostatisticsSchool of Biological and Population Health Sciences, Oregon State University, Corvallis, Oregon, USADepartment of Physiological SciencesUniversity of Florida, Gainesville, Florida, USADepartment of Large Animal Clinical SciencesUniversity of Florida, Gainesville, Florida, USAMaine Medical Center Research InstituteScarborough, Maine, USA
| | - Iske V Larkin
- Skeletal Biology LaboratorySchool of Biological and Population Health Sciences, Oregon State University, Corvallis, Oregon 97331, USACenter for Healthy Aging ResearchOregon State University, Corvallis, Oregon, USADepartment of NeuroscienceMcKnight Brain Institute, University of Florida, Gainesville, Florida, USABiostatisticsSchool of Biological and Population Health Sciences, Oregon State University, Corvallis, Oregon, USADepartment of Physiological SciencesUniversity of Florida, Gainesville, Florida, USADepartment of Large Animal Clinical SciencesUniversity of Florida, Gainesville, Florida, USAMaine Medical Center Research InstituteScarborough, Maine, USA
| | - Thomas J Wronski
- Skeletal Biology LaboratorySchool of Biological and Population Health Sciences, Oregon State University, Corvallis, Oregon 97331, USACenter for Healthy Aging ResearchOregon State University, Corvallis, Oregon, USADepartment of NeuroscienceMcKnight Brain Institute, University of Florida, Gainesville, Florida, USABiostatisticsSchool of Biological and Population Health Sciences, Oregon State University, Corvallis, Oregon, USADepartment of Physiological SciencesUniversity of Florida, Gainesville, Florida, USADepartment of Large Animal Clinical SciencesUniversity of Florida, Gainesville, Florida, USAMaine Medical Center Research InstituteScarborough, Maine, USA
| | - Clifford J Rosen
- Skeletal Biology LaboratorySchool of Biological and Population Health Sciences, Oregon State University, Corvallis, Oregon 97331, USACenter for Healthy Aging ResearchOregon State University, Corvallis, Oregon, USADepartment of NeuroscienceMcKnight Brain Institute, University of Florida, Gainesville, Florida, USABiostatisticsSchool of Biological and Population Health Sciences, Oregon State University, Corvallis, Oregon, USADepartment of Physiological SciencesUniversity of Florida, Gainesville, Florida, USADepartment of Large Animal Clinical SciencesUniversity of Florida, Gainesville, Florida, USAMaine Medical Center Research InstituteScarborough, Maine, USA
| | - Satya P Kalra
- Skeletal Biology LaboratorySchool of Biological and Population Health Sciences, Oregon State University, Corvallis, Oregon 97331, USACenter for Healthy Aging ResearchOregon State University, Corvallis, Oregon, USADepartment of NeuroscienceMcKnight Brain Institute, University of Florida, Gainesville, Florida, USABiostatisticsSchool of Biological and Population Health Sciences, Oregon State University, Corvallis, Oregon, USADepartment of Physiological SciencesUniversity of Florida, Gainesville, Florida, USADepartment of Large Animal Clinical SciencesUniversity of Florida, Gainesville, Florida, USAMaine Medical Center Research InstituteScarborough, Maine, USA
| | - Urszula T Iwaniec
- Skeletal Biology LaboratorySchool of Biological and Population Health Sciences, Oregon State University, Corvallis, Oregon 97331, USACenter for Healthy Aging ResearchOregon State University, Corvallis, Oregon, USADepartment of NeuroscienceMcKnight Brain Institute, University of Florida, Gainesville, Florida, USABiostatisticsSchool of Biological and Population Health Sciences, Oregon State University, Corvallis, Oregon, USADepartment of Physiological SciencesUniversity of Florida, Gainesville, Florida, USADepartment of Large Animal Clinical SciencesUniversity of Florida, Gainesville, Florida, USAMaine Medical Center Research InstituteScarborough, Maine, USA Skeletal Biology LaboratorySchool of Biological and Population Health Sciences, Oregon State University, Corvallis, Oregon 97331, USACenter for Healthy Aging ResearchOregon State University, Corvallis, Oregon, USADepartment of NeuroscienceMcKnight Brain Institute, University of Florida, Gainesville, Florida, USABiostatisticsSchool of Biological and Population Health Sciences, Oregon State University, Corvallis, Oregon, USADepartment of Physiological SciencesUniversity of Florida, Gainesville, Florida, USADepartment of Large Animal Clinical SciencesUniversity of Florida, Gainesville, Florida, USAMaine Medical Center Research InstituteScarborough, Maine, USA
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23
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Philbrick KA, Turner RT, Branscum AJ, Wong CP, Iwaniec UT. Paradoxical effects of partial leptin deficiency on bone in growing female mice. Anat Rec (Hoboken) 2015; 298:2018-29. [PMID: 26370912 DOI: 10.1002/ar.23267] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2014] [Revised: 02/25/2015] [Accepted: 03/24/2015] [Indexed: 11/09/2022]
Abstract
Morbidly obese, leptin-deficient ob/ob mice display low bone mass, mild osteoclast-rich osteopetrosis, and increased bone marrow adiposity. While partial leptin deficiency results in increased weight, the skeletal manifestations of partial leptin deficiency are less well defined. We therefore analyzed femora and lumbar vertebrae in growing (7-week-old) female C57BL/6 wildtype (WT) mice, partial leptin-deficient ob/+ mice, and leptin-deficient ob/ob mice. The bones were evaluated by dual energy absorptiometry, microcomputed tomography and histomorphometry. As expected, ob/+ mice were heavier, had more white adipose tissue, and lower serum leptin than WT mice, but were lighter and had less white adipose tissue than ob/ob mice. With a few exceptions, cancellous bone architecture, cell (osteoblast, osteoclast, and adipocyte), and dynamic measurements did not differ between WT and ob/+ mice. In contrast, compared to WT and ob/+ mice, ob/ob mice had lower cancellous bone volume fraction, and higher bone marrow adiposity in the femur metaphysis, and higher cancellous bone volume fraction in lumbar vertebra. Paradoxically, ob/+ mice had greater femoral bone volume than either WT or ob/ob mice. There was a positive correlation between body weight and femur volume in all three genotypes. However, the positive effect of weight on bone occurred with lower body weight in leptin-producing mice. The paradoxical differences in bone size among WT, ob/+, and ob/ob mice may be explained if leptin, in addition to stimulating bone growth and cancellous bone turnover, acts to lower the set-point at which increased body weight leads to a commensurate increase in bone size.
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Affiliation(s)
- Kenneth A Philbrick
- Skeletal Biology Laboratory, School of Biological and Population Health Sciences, Oregon State University, Corvallis, 97331, OR
| | - Russell T Turner
- Skeletal Biology Laboratory, School of Biological and Population Health Sciences, Oregon State University, Corvallis, 97331, OR.,Center for Healthy Aging Research, Oregon State University, Corvallis, 97331, OR
| | - Adam J Branscum
- Biostatistics Program, School of Biological and Population Health Sciences, Oregon State University, Corvallis, 97331, OR
| | - Carmen P Wong
- Skeletal Biology Laboratory, School of Biological and Population Health Sciences, Oregon State University, Corvallis, 97331, OR
| | - Urszula T Iwaniec
- Skeletal Biology Laboratory, School of Biological and Population Health Sciences, Oregon State University, Corvallis, 97331, OR.,Center for Healthy Aging Research, Oregon State University, Corvallis, 97331, OR
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24
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Wheeler RL, Hampton AD, Langley NR. The effects of body mass index and age on cross-sectional properties of the femoral neck. Clin Anat 2015; 28:1048-57. [DOI: 10.1002/ca.22632] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2015] [Revised: 09/13/2015] [Accepted: 09/14/2015] [Indexed: 01/22/2023]
Affiliation(s)
- Rachel L. Wheeler
- Department of Anatomy; Lincoln Memorial University-DeBusk College of Osteopathic Medicine, Harrogate; Tennessee
| | - Aaron D. Hampton
- Department of Anatomy; Lincoln Memorial University-DeBusk College of Osteopathic Medicine, Harrogate; Tennessee
| | - Natalie R. Langley
- Department of Anatomy; Lincoln Memorial University-DeBusk College of Osteopathic Medicine, Harrogate; Tennessee
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25
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Cao JJ, Picklo MJ. Involuntary wheel running improves but does not fully reverse the deterioration of bone structure of obese rats despite decreasing adiposity. Calcif Tissue Int 2015; 97:145-55. [PMID: 25903229 DOI: 10.1007/s00223-015-9992-6] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/26/2015] [Accepted: 03/31/2015] [Indexed: 10/23/2022]
Abstract
This study investigated whether exercise or antioxidant supplementation with vitamin C and E during exercise affects bone structure and markers of bone metabolism in obese rat. Sprague-Dawley rats, 6-week old, were fed a normal-fat diet (NF, 10 % kcal as fat) and a high-fat diet (HF, 45 % with extra fat from lard) ad libitum for 14 weeks. Then, rats on the high-fat diet were assigned randomly to three treatment groups for additional 12 weeks with forced exercise: HF; HF + exercise (HF + Ex); and HF with vitamin C (0.5 g ascorbate/kg diet) and vitamin E (0.4 g α-tocopherol acetate/kg diet) supplementation + exercise (HF + Ex + VCE). At the end of the study, body weight and fat (%) were similar among NF, HF + Ex, and HF + Ex + VCE, whereas HF had greater body weight and fat (%) than other groups. Compared to NF, HF had elevated serum leptin, tartrate-resistant acid phosphatase (TRAP), and IGF-1; increased trabecular separation and structural model index; and lowered bone mineral density, trabecular connectivity density, and trabecular number in distal femur, while HF + Ex and HF + Ex + VCE had elevated serum TRAP and decreased bone volume/total volume and trabecular number of distal femurs. Compared to HF, HF + Ex and HF + Ex + VCE had decreased serum TRAP and osteocalcin and improved bone structural properties of the distal femur. These findings suggest that exercise, while decreasing body fat, does not fully protect against the negative skeletal effects of existing obesity induced by a high-fat diet. Furthermore, vitamin C and E supplementation has no additional benefits on bone structural properties during exercise.
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Affiliation(s)
- Jay J Cao
- Grand Forks Human Nutrition Research Center, USDA, Agricultural Research Service, 2420 2nd Ave N, Grand Forks, ND, 58202-9034, USA,
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26
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Sahin Ersoy G, Giray B, Subas S, Simsek E, Sakin O, Turhan OT, Bulut S. Interpregnancy interval as a risk factor for postmenopausal osteoporosis. Maturitas 2015; 82:236-40. [PMID: 26254682 DOI: 10.1016/j.maturitas.2015.07.014] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2015] [Revised: 07/13/2015] [Accepted: 07/14/2015] [Indexed: 11/26/2022]
Abstract
OBJECTIVE Bone mass loss associated with pregnancy and lactation is usually regained in the postpartum period. However, it is not known whether the bone loss is completely recovered in women with a shortened interpregnancy interval (IPI). The aim of this study was to analyze the effect of IPI and gynecological history on postmenopausal osteoporosis. STUDY DESIGN The study was conducted among 537 postmenopausal women who were divided into two groups in accordance with the osteoporosis status. Prior to bone densitometry, the patients were questioned about reproductive history. Dual-energy X-ray absorptiometry was used to measure lumbar spinal, femur neck and total femoral bone mineral density. MAIN OUTCOME MEASURE Association between IPI and postmenopausal osteoporosis was analyzed. RESULTS The comparison of both groups according to the total duration of breastfeeding did not reveal a considerable variation (p=0.288). In the osteoporosis group the age and duration of menopause were found to be significantly higher (p<0.001) whereas the age of first pregnancy and IPI were notably lower in comparison to the controls group (p<0.001). Multivariate logistic regression analyses revealed that women who have 0-12 months interpregnancy interval have the highest risk for osteoporosis (OR: 4.306; 95% CI, 1.684-11.01). This analysis confirmed that the occurrence of first pregnancy under 27 years of age conveyed a higher risk for osteoporosis, as well. CONCLUSIONS Shortened IPI may have a detrimental effect on bone mineral density in postmenopausal age.
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Affiliation(s)
- Gulcin Sahin Ersoy
- Department of Obstetrics and Gynecology, Kartal Dr. Lutfi Kirdar Education and Research Hospital, Istanbul, Turkey.
| | - Burak Giray
- Department of Obstetrics and Gynecology, Kartal Dr. Lutfi Kirdar Education and Research Hospital, Istanbul, Turkey
| | - Seda Subas
- Department of Obstetrics and Gynecology, Kartal Dr. Lutfi Kirdar Education and Research Hospital, Istanbul, Turkey
| | - Ersin Simsek
- Department of Family Medicine, Kartal Dr. Lutfi Kirdar Education and Research Hospital, Istanbul, Turkey
| | - Onder Sakin
- Department of Obstetrics and Gynecology, Kartal Dr. Lutfi Kirdar Education and Research Hospital, Istanbul, Turkey
| | - Omer Talip Turhan
- Department of Obstetrics and Gynecology, Kartal Dr. Lutfi Kirdar Education and Research Hospital, Istanbul, Turkey
| | - Sadullah Bulut
- Department of Obstetrics and Gynecology, Kartal Dr. Lutfi Kirdar Education and Research Hospital, Istanbul, Turkey
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27
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Turner RT, Philbrick KA, Wong CP, Olson DA, Branscum AJ, Iwaniec UT. Morbid obesity attenuates the skeletal abnormalities associated with leptin deficiency in mice. J Endocrinol 2014; 223:M1-15. [PMID: 24990938 PMCID: PMC4161659 DOI: 10.1530/joe-14-0224] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Leptin-deficient ob/ob mice are morbidly obese and exhibit low total bone mass and mild osteopetrosis. In order to disassociate the skeletal effects of leptin deficiency from those associated with morbid obesity, we evaluated bone mass, architecture, gene expression, and indices of bone turnover in WT mice, ob/ob mice allowed to feed ad libitum (ob/ob), and ob/ob mice pair-fed equivalent to WT mice (pair-fed ob/ob). Mice were maintained at 32 °C (thermoneutral) from 6 to 18 weeks of age to minimize differences in resting energy expenditure. ob/ob mice were heavier, had more abdominal white adipose tissue (WAT), and were hyperglycemic compared with WT mice. Femur length, bone mineral content (BMC) and bone mineral density, and midshaft femur cortical thickness were lower in ob/ob mice than in WT mice. Cancellous bone volume (BV) fraction was higher but indices of bone formation and resorption were lower in ob/ob mice compared with WT mice; reduced bone resorption in ob/ob mice resulted in pathological retention of calcified cartilage. Pair-fed ob/ob mice were lighter and had lower WAT, uterine weight, and serum glucose than ob/ob mice. Similarly, femoral length, BMC, and cortical thickness were lower in pair-fed ob/ob mice compared with ob/ob mice, as were indices of cancellous bone formation and resorption. In contrast, bone marrow adiposity, calcified cartilage, and cancellous BV fraction were higher at one or more cancellous sites in pair-fed ob/ob mice compared with ob/ob mice. These findings indicate that the skeletal abnormalities caused by leptin deficiency are markedly attenuated in morbidly obese ob/ob mice.
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Affiliation(s)
- Russell T Turner
- Skeletal Biology LaboratorySchool of Biological and Population Health SciencesCenter for Healthy Aging ResearchBiostatisticsSchool of Biological and Population Health Sciences, Oregon State University, Corvallis, Oregon 97331, USA Skeletal Biology LaboratorySchool of Biological and Population Health SciencesCenter for Healthy Aging ResearchBiostatisticsSchool of Biological and Population Health Sciences, Oregon State University, Corvallis, Oregon 97331, USA
| | - Kenneth A Philbrick
- Skeletal Biology LaboratorySchool of Biological and Population Health SciencesCenter for Healthy Aging ResearchBiostatisticsSchool of Biological and Population Health Sciences, Oregon State University, Corvallis, Oregon 97331, USA
| | - Carmen P Wong
- Skeletal Biology LaboratorySchool of Biological and Population Health SciencesCenter for Healthy Aging ResearchBiostatisticsSchool of Biological and Population Health Sciences, Oregon State University, Corvallis, Oregon 97331, USA
| | - Dawn A Olson
- Skeletal Biology LaboratorySchool of Biological and Population Health SciencesCenter for Healthy Aging ResearchBiostatisticsSchool of Biological and Population Health Sciences, Oregon State University, Corvallis, Oregon 97331, USA
| | - Adam J Branscum
- Skeletal Biology LaboratorySchool of Biological and Population Health SciencesCenter for Healthy Aging ResearchBiostatisticsSchool of Biological and Population Health Sciences, Oregon State University, Corvallis, Oregon 97331, USA
| | - Urszula T Iwaniec
- Skeletal Biology LaboratorySchool of Biological and Population Health SciencesCenter for Healthy Aging ResearchBiostatisticsSchool of Biological and Population Health Sciences, Oregon State University, Corvallis, Oregon 97331, USA Skeletal Biology LaboratorySchool of Biological and Population Health SciencesCenter for Healthy Aging ResearchBiostatisticsSchool of Biological and Population Health Sciences, Oregon State University, Corvallis, Oregon 97331, USA
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de Albuquerque Maia L, Lisboa PC, de Oliveira E, da Silva Lima N, Lima ICB, Lopes RT, Ruffoni LDG, Nonaka KO, de Moura EG. Bone metabolism in obese rats programmed by early weaning. Metabolism 2014; 63:352-64. [PMID: 24355624 DOI: 10.1016/j.metabol.2013.11.010] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/25/2013] [Revised: 11/11/2013] [Accepted: 11/12/2013] [Indexed: 01/24/2023]
Abstract
OBJECTIVE Obesity and osteoporosis seem to have a common pathogenesis, especially because bone and adipose tissue have common origins. Since early weaning (EW) decreases adipogenesis and osteogenesis in neonate, further programming for obesity and hyperleptinemia, we hypothesized that these changes in adipogenesis could affect bone metabolism. MATERIALS/METHODS Lactating rats were separated into 3 groups: control - dams whose pups ate milk throughout lactation; mechanical EW (MEW) - dams were involved with a bandage interrupting suckling in the last 3days of lactation; pharmacological EW (PEW) - dams were bromocriptine-treated (0.5mg/twice a day via intraperitoneal injection) 3days before weaning. The adult offspring was subjected to dual-energy X-ray absorptiometry and bone tissue was also evaluated by computed tomography, microcomputed tomography and biomechanical tests, beyond serum analyses. RESULTS MEW and PEW presented higher total bone mineral density (BMD), total bone mineral content, spine BMD and bone area in postnatal day 150 (PN150). In PN180, both groups also presented increase of these parameters and higher femur BMD and fourth lumbar vertebra (LV4) BMD, femoral head radiodensity and LV4 vertebral body radiodensity, trabecular number, stiffness and break load; lower trabecular separation, maximal deformation and break deformation, and also hyperleptinemia and higher visceral fat mass and 25-hydroxivitamin D, whereas parathyroid hormone was unchanged. Serum C-terminal cross-linked telopeptide of type I collagen was lower for both groups. CONCLUSIONS Since both models program for obesity and increased bone mass, and leptin increases plasma vitamin D levels, probably leptin is the link between obesity and higher bone mass.
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Affiliation(s)
- Lígia de Albuquerque Maia
- Department of Physiological Sciences, State University of Rio de Janeiro, State University of Rio de Janeiro, Rio de Janeiro, RJ 20550-030, Brazil
| | - Patrícia Cristina Lisboa
- Department of Physiological Sciences, State University of Rio de Janeiro, State University of Rio de Janeiro, Rio de Janeiro, RJ 20550-030, Brazil
| | - Elaine de Oliveira
- Department of Physiological Sciences, State University of Rio de Janeiro, State University of Rio de Janeiro, Rio de Janeiro, RJ 20550-030, Brazil
| | - Natália da Silva Lima
- Department of Physiological Sciences, State University of Rio de Janeiro, State University of Rio de Janeiro, Rio de Janeiro, RJ 20550-030, Brazil
| | - Inaya Correa Barbosa Lima
- Nuclear Instrumentation Laboratory, COPPE-PEN, Federal University of Rio de Janeiro, Rio de Janeiro, RJ 21941-972, Brazil
| | - Ricardo Tadeu Lopes
- Nuclear Instrumentation Laboratory, COPPE-PEN, Federal University of Rio de Janeiro, Rio de Janeiro, RJ 21941-972, Brazil
| | | | - Keico Okino Nonaka
- Laboratory of Exercise Physiology, Federal University of São Carlos, São Carlos, São Paulo, SP 13565-905, Brazil
| | - Egberto Gaspar de Moura
- Department of Physiological Sciences, State University of Rio de Janeiro, State University of Rio de Janeiro, Rio de Janeiro, RJ 20550-030, Brazil.
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Gallagher EJ, Sun H, Kornhauser C, Tobin-Hess A, Epstein S, Yakar S, LeRoith D. The effect of dipeptidyl peptidase-IV inhibition on bone in a mouse model of type 2 diabetes. Diabetes Metab Res Rev 2014; 30:191-200. [PMID: 24023014 PMCID: PMC5496098 DOI: 10.1002/dmrr.2466] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/28/2013] [Accepted: 09/05/2013] [Indexed: 02/05/2023]
Abstract
BACKGROUND Individuals with type 2 diabetes (T2D) are at greater risk of bone fractures than those without diabetes. Certain oral diabetic medications may further increase the risk of fracture. Dipeptidyl peptidase-IV (DPP-IV) inhibitors are incretin-based therapies that are being increasingly used for the management of T2D. It has been hypothesized that these agents may reduce fracture risk in those with T2D. In this study, we used a mouse model of T2D to examine the effects of the DPP-IV inhibitor, MK-0626, on bone. METHODS Male wild type (WT) and diabetic muscle-lysine-arginine (MKR) mice were treated with MK-0626, pioglitazone, alendronate or vehicle. The effects of treatment with MK-0626 on bone microarchitecture and turnover were compared with treatment with pioglitazone, alendronate and vehicle. Osteoblast differentiation was determined by alkaline phosphatase staining of bone marrow cells from WT and MKR mice after treatment with pioglitazone, MK-0626 or phosphate buffered saline. RESULTS We found that MK-0626 had neutral effects on cortical and trabecular bone in diabetic mice. Pioglitazone had detrimental effects on the trabecular bone of WT but not of diabetic mice. Alendronate caused improvements in cortical and trabecular bone architecture in diabetic and WT mice. MK-0626 did not alter osteoblast differentiation, but pioglitazone impaired osteoblast differentiation in vitro. CONCLUSIONS Overall, the DPP-IV inhibitor, MK-0626, had no adverse effects on bone in an animal model of T2D or directly on osteoblasts in culture. These findings are reassuring as DPP-IV inhibitors are being widely used to treat patients with T2D who are already at an increased risk of fractures.
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Affiliation(s)
- Emily Jane Gallagher
- Division of Endocrinology, Diabetes and Bone Diseases, Department of Medicine, Mount Sinai School of Medicine, New York, NY, USA
| | - Hui Sun
- David B. Kriser Dental Center, Department of Basic Science and Craniofacial Biology, New York University College of Dentistry, New York, NY, USA
| | - Caroline Kornhauser
- Division of Endocrinology, Diabetes and Bone Diseases, Department of Medicine, Mount Sinai School of Medicine, New York, NY, USA
| | - Aviva Tobin-Hess
- Division of Endocrinology, Diabetes and Bone Diseases, Department of Medicine, Mount Sinai School of Medicine, New York, NY, USA
| | - Sol Epstein
- Department of Medicine and Geriatrics, Mount Sinai School of Medicine, New York, NY, USA
| | - Shoshana Yakar
- David B. Kriser Dental Center, Department of Basic Science and Craniofacial Biology, New York University College of Dentistry, New York, NY, USA
| | - Derek LeRoith
- Division of Endocrinology, Diabetes and Bone Diseases, Department of Medicine, Mount Sinai School of Medicine, New York, NY, USA
- Correspondence to: Derek LeRoith, Division of Endocrinology, Metabolism, and Bone Diseases, Department of Medicine, Mount Sinai School of Medicine, New York, NY, USA.
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Iwaniec UT, Turner RT, Smith BJ, Stoecker BJ, Rust A, Zhang B, Vasu VT, Gohil K, Cross CE, Traber MG. Evaluation of long-term vitamin E insufficiency or excess on bone mass, density, and microarchitecture in rodents. Free Radic Biol Med 2013; 65:1209-1214. [PMID: 24051180 PMCID: PMC3859709 DOI: 10.1016/j.freeradbiomed.2013.09.004] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/17/2013] [Revised: 09/04/2013] [Accepted: 09/07/2013] [Indexed: 12/19/2022]
Abstract
High dietary α-tocopherol levels reportedly result in osteopenia in growing rats, whereas α-tocopherol deficiency in α-tocopherol transfer protein-knockout (α-TTP-KO) mice results in increased cancellous bone mass. Because osteoporosis is a disease associated primarily with aging, we hypothesized that age-related bone loss would be attenuated in α-TTP-KO mice. Cancellous and cortical bone mass and microarchitecture were assessed using dual-energy X-ray absorptiometry and micro-computed tomography in 2-year-old α-TTP-KO and wild-type (WT) male and female mice fed dl-α-tocopherol acetate. In contrast to our expectations, differences in cancellous bone were not detected between WT and α-TTP-KO mice of either gender, and α-TTP-KO males had lower (p<0.05) cortical bone mass than WT males. We therefore evaluated bone mass, density, and microarchitecture in proximal femur of skeletally mature (8.5-month-old) male Sprague-Dawley rats fed diets containing low (15 IU/kg diet), adequate (75 IU/kg diet), or high (500 IU/kg diet) dl-α-tocopherol acetate for 13 weeks. Low dietary α-tocopherol did not increase bone mass. Furthermore, no reductions in cancellous or cortical bone mass were detected with high dietary α-tocopherol. Failure to detect increased bone mass in aged α-TTP-KO mice or bone changes in skeletally mature rats fed either low or high levels of α-tocopherol does not support the hypothesis that α-tocopherol has a negative impact on bone mass, density, or microarchitecture in rodents.
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Affiliation(s)
- Urszula T Iwaniec
- Skeletal Biology Laboratory, Oregon State University, Corvallis, OR 97331, USA; Center for Healthy Aging Research, Oregon State University, Corvallis, OR 97331, USA
| | - Russell T Turner
- Skeletal Biology Laboratory, Oregon State University, Corvallis, OR 97331, USA; Center for Healthy Aging Research, Oregon State University, Corvallis, OR 97331, USA
| | - Brenda J Smith
- Department of Nutritional Sciences, College of Human Sciences, Oklahoma State University, Stillwater, OK 74078, USA
| | - Barbara J Stoecker
- Department of Nutritional Sciences, College of Human Sciences, Oklahoma State University, Stillwater, OK 74078, USA
| | - Allison Rust
- Skeletal Biology Laboratory, Oregon State University, Corvallis, OR 97331, USA
| | - Bo Zhang
- Biostatistics Core, School of Biological and Population Health Sciences, Oregon State University, Corvallis, OR 97331, USA
| | - Vihas T Vasu
- Department of Internal Medicine, Genome and Biomedical Sciences Facility, University of California at Davis, Davis, CA 95616, USA
| | - Kishorchandra Gohil
- Department of Internal Medicine, Genome and Biomedical Sciences Facility, University of California at Davis, Davis, CA 95616, USA
| | - Carroll E Cross
- Department of Internal Medicine, Genome and Biomedical Sciences Facility, University of California at Davis, Davis, CA 95616, USA
| | - Maret G Traber
- Linus Pauling Institute, Oregon State University, Corvallis, OR 97331, USA.
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Turner RT, Kalra SP, Wong CP, Philbrick KA, Lindenmaier LB, Boghossian S, Iwaniec UT. Peripheral leptin regulates bone formation. J Bone Miner Res 2013; 28:22-34. [PMID: 22887758 PMCID: PMC3527690 DOI: 10.1002/jbmr.1734] [Citation(s) in RCA: 179] [Impact Index Per Article: 16.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/25/2012] [Revised: 06/30/2012] [Accepted: 07/16/2012] [Indexed: 12/15/2022]
Abstract
Substantial evidence does not support the prevailing view that leptin, acting through a hypothalamic relay, decreases bone accrual by inhibiting bone formation. To clarify the mechanisms underlying regulation of bone architecture by leptin, we evaluated bone growth and turnover in wild-type (WT) mice, leptin receptor-deficient db/db mice, leptin-deficient ob/ob mice, and ob/ob mice treated with leptin. We also performed hypothalamic leptin gene therapy to determine the effect of elevated hypothalamic leptin levels on osteoblasts. Finally, to determine the effects of loss of peripheral leptin signaling on bone formation and energy metabolism, we used bone marrow (BM) from WT or db/db donor mice to reconstitute the hematopoietic and mesenchymal stem cell compartments in lethally irradiated WT recipient mice. Decreases in bone growth, osteoblast-lined bone perimeter and bone formation rate were observed in ob/ob mice and greatly increased in ob/ob mice following subcutaneous administration of leptin. Similarly, hypothalamic leptin gene therapy increased osteoblast-lined bone perimeter in ob/ob mice. In spite of normal osteoclast-lined bone perimeter, db/db mice exhibited a mild but generalized osteopetrotic-like (calcified cartilage encased by bone) skeletal phenotype and greatly reduced serum markers of bone turnover. Tracking studies and histology revealed quantitative replacement of BM cells following BM transplantation. WT mice engrafted with db/db BM did not differ in energy homeostasis from untreated WT mice or WT mice engrafted with WT BM. Bone formation in WT mice engrafted with WT BM did not differ from WT mice, whereas bone formation in WT mice engrafted with db/db cells did not differ from the low rates observed in untreated db/db mice. In summary, our results indicate that leptin, acting primarily through peripheral pathways, increases osteoblast number and activity.
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Affiliation(s)
- Russell T. Turner
- Skeletal Biology Laboratory, School of Biological and Population Health Sciences, Oregon State University, Corvallis, OR, 97331, USA
| | - Satya P. Kalra
- Department of Neuroscience, University of Florida McKnight Brain Institute, Gainesville, FL, 32610, USA
| | - Carmen P. Wong
- Molecular and Cellular Nutrition Laboratory, School of Biological and Population Health Sciences, Oregon State University, Corvallis, OR, 97331, USA
| | - Kenneth A. Philbrick
- Skeletal Biology Laboratory, School of Biological and Population Health Sciences, Oregon State University, Corvallis, OR, 97331, USA
| | - Laurence B. Lindenmaier
- Skeletal Biology Laboratory, School of Biological and Population Health Sciences, Oregon State University, Corvallis, OR, 97331, USA
| | - Stephane Boghossian
- Department of Neuroscience, University of Florida McKnight Brain Institute, Gainesville, FL, 32610, USA
| | - Urszula T. Iwaniec
- Skeletal Biology Laboratory, School of Biological and Population Health Sciences, Oregon State University, Corvallis, OR, 97331, USA
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Cao JJ, Gregoire BR, Sun L, Song S. Alpha-1 antitrypsin reduces ovariectomy-induced bone loss in mice. Ann N Y Acad Sci 2012; 1240:E31-5. [PMID: 22360827 DOI: 10.1111/j.1749-6632.2011.06370.x] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Proinflammatory cytokines are primary mediators of bone loss in estrogen deficiency. This study determined whether alpha-1 antitrypsin (AAT), a multifunctional protein with proteinase inhibitor and anti-inflammatory activities, mitigates bone loss induced by estrogen deficiency. Mice were either sham-operated or ovariectomized and injected with either AAT or phosphate buffered saline (PBS). Ovariectomy resulted in decreased wet uterus weight, significant bone loss, increased serum leptin concentrations, and higher body weight compared to sham. AAT injection increased tibial trabecular bone volume/total volume and trabecular thickness compared to PBS injection in ovariectomized mice. Ovariectomized mice with AAT treatment had higher uterus weight, lower serum osteocalcin levels, fewer bone marrow tartrate-resistant acid phosphatase-positive osteoclasts, and less expression of calcitonin receptor in bone than that in PBS-injected mice. These data demonstrate that AAT mitigates ovariectomy-induced bone loss in mice possibly through inhibiting osteoclast activity and bone resorption.
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Affiliation(s)
- Jay J Cao
- USDA, Agricultural Research Service, Grand Forks Human Nutrition Research Center, Grand Forks, North Dakota 58202-9034, USA.
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Iwaniec UT, Boghossian S, Trevisiol CH, Wronski TJ, Turner RT, Kalra SP. Hypothalamic leptin gene therapy prevents weight gain without long-term detrimental effects on bone in growing and skeletally mature female rats. J Bone Miner Res 2011; 26:1506-16. [PMID: 21328617 PMCID: PMC3129999 DOI: 10.1002/jbmr.365] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Hypothalamic leptin gene therapy normalizes the mosaic skeletal phenotype of leptin-deficient ob/ob mice. However, it is not clear whether increased hypothalamic leptin alters bone metabolism in animals already producing the hormone. The objective of this study was to evaluate the long duration effects of recombinant adeno-associated virus-rat leptin (rAAV-Lep) hypothalamic gene therapy on weight gain and bone metabolism in growing and skeletally mature leptin-replete female Sprague-Dawley rats. Rats were either unoperated or implanted with cannulas in the third ventricle of the hypothalamus and injected with either rAAV-Lep or rAAV-GFP (control vector encoding green fluorescent protein) and maintained on standard rat chow fed ad libitum for either 5 or 10 weeks (starting at 3 months of age) or 18 weeks (starting at 9 months of age). Tibias, femurs, or lumbar vertebrae were analyzed by micro-computed tomography and/or histomorphometry. In comparison with age-matched rAAV-GFP rats, rAAV-Lep rats maintained a lower body weight for the duration of studies. At 5 weeks after vector administration, rAAV-Lep rats had lower cancellous bone volume and bone marrow adiposity but higher osteoblast perimeter compared with nonoperated controls. However, these values did not differ between the two groups at 10 weeks after vector administration. Differences in cancellous bone volume and architecture were not detected between the rAAV-Lep and rAAV-GFP groups at either time point. Also, rAAV-Lep had no negative effects on bone in the 9-month-old skeletally mature rats at 18 weeks after vector administration. We hypothesize that the transient reductions in bone mass and bone marrow adiposity at 5 weeks after vector administration were due to hypothalamic surgery. We conclude that increased hypothalamic leptin, sufficient to prevent weight gain, has minimal specific effects (rAAV-Lep versus rAAV-GFP) on bone metabolism in normal female rats.
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Affiliation(s)
- Urszula T Iwaniec
- Department of Nutrition and Exercise Sciences, Oregon State University, Corvallis, OR 97331, USA.
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Costa CASD, Carlos AS, Gonzalez GDPL, Reis RPG, Ribeiro MDS, dos Santos ADS, Monteiro AMV, de Moura EG, Nascimento-Saba CCAD. Diet containing low n-6/n-3 polyunsaturated fatty acids ratio, provided by canola oil, alters body composition and bone quality in young rats. Eur J Nutr 2011; 51:191-8. [DOI: 10.1007/s00394-011-0206-3] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2011] [Accepted: 05/09/2011] [Indexed: 11/25/2022]
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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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Cvijetic S, Pavlovic M, Pasalic D, Dodig S. Ultrasound bone measurement in an older population with metabolic syndrome. Aging Clin Exp Res 2011; 23:29-34. [PMID: 21499017 DOI: 10.1007/bf03324950] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
BACKGROUND AND AIMS Metabolic syndrome and osteoporosis are recognized as major public health problems in many countries. This study investigated the association between bone quality and components of metabolic syndrome in an elderly population. METHODS The study included a population sample of 211 men and women, of mean age 77.9 ± 4.5 years. Anthropometry, blood pressure, serum levels of lipoproteins (HDL and LDL), triglycerides and glucose were measured, and ultrasound bone densitometry was performed in all subjects. Information on lifestyle habits, including physical activity, smoking and alcohol consumption, were obtained by a questionnaire. RESULTS Metabolic syndrome, defined by the criteria of the International Diabetes Federation, was determined in 59% of men and 65% of women. The quantitative ultrasound index (QUI) was significantly correlated with serum glucose in men (r=-0.31; p=0.005) and with body mass index (BMI) in women (r=0.39; p<0.0001). QUI was significantly lower in men with metabolic syndrome (F=7.57; p<0.007) and significantly higher in women with it (F=6.47; p=0.012) compared with controls. When QUI was adjusted for body mass index in women and for serum glucose in men, it was no longer significantly different from values for controls. Other covariates such as cholesterol, blood pressure, smoking, alcohol, and physical activity did not change the difference in QUI between patients with metabolic syndrome and controls. Diabetes in men (p=0.005) and obesity and waist circumference in women (p<0.05) were also significant predictors of QUI in regression analysis. CONCLUSIONS The association between metabolic syndrome and bone stiffness in elderly people may be explained by increased BMI in women and high serum glucose in men.
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Ma H, Turpeinen T, Silvennoinen M, Torvinen S, Rinnankoski-Tuikka R, Kainulainen H, Timonen J, Kujala UM, Rahkila P, Suominen H. Effects of diet-induced obesity and voluntary wheel running on the microstructure of the murine distal femur. Nutr Metab (Lond) 2011; 8:1. [PMID: 21241467 PMCID: PMC3034661 DOI: 10.1186/1743-7075-8-1] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2010] [Accepted: 01/17/2011] [Indexed: 12/14/2022] Open
Abstract
Background Obesity and osteoporosis, two possibly related conditions, are rapidly expanding health concerns in modern society. Both of them are associated with sedentary life style and nutrition. To investigate the effects of diet-induced obesity and voluntary physical activity we used high resolution micro-computed tomography (μCT) together with peripheral quantitative computed tomography (pQCT) to examine the microstructure of the distal femoral metaphysis in mice. Methods Forty 7-week-old male C57BL/6J mice were assigned to 4 groups: control (C), control + running (CR), high-fat diet (HF), and high-fat diet + running (HFR). After a 21-week intervention, all the mice were sacrificed and the left femur dissected for pQCT and μCT measurements. Results The mice fed the high-fat diet showed a significant weight gain (over 70% for HF and 60% for HFR), with increased epididymal fat pad mass and impaired insulin sensitivity. These obese mice had significantly higher trabecular connectivity density, volume, number, thickness, area and mass, and smaller trabecular separation. At the whole bone level, they had larger bone circumference and cross-sectional area and higher density-weighted maximal, minimal, and polar moments of inertia. Voluntary wheel running decreased all the cortical bone parameters, but increased the trabecular mineral density, and decreased the pattern factor and structure model index towards a more plate-like structure. Conclusions The results suggest that in mice the femur adapts to obesity by improving bone strength both at the whole bone and micro-structural level. Adaptation to running exercise manifests itself in increased trabecular density and improved 3D structure, but in a limited overall bone growth
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Affiliation(s)
- Hongqiang Ma
- Department of Health Sciences, University of Jyväskylä, Finland.
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Costa CASD, Carlos AS, dos Santos ADS, Monteiro AMV, Moura EGD, Nascimento-Saba CCA. Abdominal adiposity, insulin and bone quality in young male rats fed a high-fat diet containing soybean or canola oil. Clinics (Sao Paulo) 2011; 66:1811-6. [PMID: 22012056 PMCID: PMC3180158 DOI: 10.1590/s1807-59322011001000022] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/05/2011] [Revised: 05/30/2011] [Accepted: 07/05/2011] [Indexed: 11/21/2022] Open
Abstract
OBJECTIVES A low ratio of omega-6/omega-3 polyunsaturated fatty acids is associated with healthy bone properties. However, fatty diets can induce obesity. Our objective was to evaluate intra-abdominal adiposity, insulin, and bone growth in rats fed a high-fat diet containing low ratios of omega-6/omega-3 provided in canola oil. METHODS After weaning, rats were grouped and fed either a control diet (7S), a high-fat diet containing soybean oil (19S) or a high-fat diet of canola oil (19C) until they were 60 days old. Differences were considered to be significant if p<0.05. RESULTS After 60 days, the 19S and 19C groups showed more energy intake, body density growth and intraabdominal fat mass. However, the 19S group had a higher area (200%) and a lower number (44%) of adipocytes, while the 7S and 19C groups did not differ. The serum concentrations of glucose and insulin and the insulin resistance index were significantly increased in the 19C group (15%, 56%, and 78%, respectively) compared to the 7S group. Bone measurements of the 19S and 19C groups showed a higher femur mass (25%) and a higher lumbar vertebrae mass (11%) and length (5%). Computed tomography analysis revealed more radiodensity in the proximal femoral epiphysis and lumbar vertebrae of 19C group compared to the 7S and 19S groups. CONCLUSIONS Our results suggest that the amount and source of fat used in the diet after weaning increase body growth and fat depots and affect insulin resistance and, consequently, bone health.
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Scheller EL, Song J, Dishowitz MI, Soki FN, Hankenson KD, Krebsbach PH. Leptin functions peripherally to regulate differentiation of mesenchymal progenitor cells. Stem Cells 2010; 28:1071-80. [PMID: 20506495 DOI: 10.1002/stem.432] [Citation(s) in RCA: 78] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Leptin functions through a well-documented central neuroendocrine pathway to regulate bone mass. However, the ability of leptin to modulate bone mass through a peripheral mechanism has been debated due to conflicting in vitro results and lack of sufficient in vivo models. We utilized mice with LoxP sites introduced into the long-form leptin receptor (ObRb) gene to determine how leptin regulates mesenchymal progenitor cell (MPC) differentiation and osteoblast function in vitro and in vivo. Rapid phosphorylation of Stat3 after leptin treatment of bone marrow stromal cells (BMSCs) from mice with conditional deletion of ObRb in macrophages (LysM(Cre+F/F)) confirmed expression of functional leptin receptors by BMSCs. Adenovirus-Cre mediated disruption of ObRb in primary stromal cells decreased mineralization and increased adipogenesis. In contrast, BMSCs harvested from leptin-signaling deficient Ob/Ob or Db/Db mice showed increased mineralization. To determine the physiologic relevance of these differences, mice with cell-specific deletion of ObRb in mesenchymal precursors (3.6(Cre+F/F)) or osteoblasts (2.3(Cre+F/F)) were generated. Although the 2.3(Cre+F/F) mice were grossly normal, the 3.6(Cre+F/F) mice displayed mild obesity that was not attributed to food intake. Femurs of 3.6(Cre+F/F) animals showed a 58%-61.9% increase in trabecular bone volume and a 65.5%-74% increase in bone mineral density. Cortical volume and mineral content were also increased 18%-22%. Primary 3.6(Cre+F/F) BMSCs recapitulated the high mineralization phenotype of Ob/Ob and Db/Db BMSCs. We conclude that leptin may have multiple peripheral roles depending on the differentiation state of MPC. Leptin (a) helps maintain MPCs in an undifferentiated state and (b) promotes mineralization of more differentiated osteoblasts.
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Affiliation(s)
- Erica L Scheller
- Department of Biologic and Materials Sciences, University of Michigan School of Dentistry, Ann Arbor, Michigan, USA
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Turner R, Iwaniec U. Moderate weight gain does not influence bone metabolism in skeletally mature female rats. Bone 2010; 47:631-5. [PMID: 20601291 PMCID: PMC2926277 DOI: 10.1016/j.bone.2010.06.010] [Citation(s) in RCA: 14] [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] [Received: 04/11/2010] [Accepted: 06/12/2010] [Indexed: 01/07/2023]
Abstract
Bone mass is correlated with body weight during growth. However, it is unclear how bone mass is influenced by weight gain following skeletal maturity. The purpose of this study was to determine the effects of weight maintenance and two rates of weight gain on bone metabolism using skeletally mature female rats. Eight-month-old female rats were fed one of 3 diets for 13 weeks: Lieber-DeCarli liquid diet ad lib (control diet), the same diet with caloric restriction to maintain initial body weight (calorie-restricted diet), and the same diet fed ad lib with the exception that appetite was enhanced (calorie-increased diet) by replacing a small quantity of maltose-dextran isocalorically with ethanol (0.5% caloric intake). Compared to baseline, rats fed the calorie-restricted, control, and calorie-increased diets changed in weight by -1+/-2% (mean+/-SE), 10+/-3%, and 21+/-2%, respectively. Weight gain was associated with a significant increase in serum leptin, a putative regulator of bone formation. In contrast, significant differences in tibial bone mineral content and density were not detected among treatments groups following dietary intervention or between treatment groups and the baseline group. Similarly, indices of cancellous bone architecture (area, trabecular number, thickness, and separation) and bone turnover (mineralizing perimeter, mineral apposition rate, and bone formation rate) did not differ among groups following dietary intervention. Our findings suggest that neither weight gain nor increased serum leptin levels, over the range evaluated, influence bone metabolism in skeletally mature female rats.
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Affiliation(s)
- R.T. Turner
- Department of Nutrition and Exercise Sciences, Oregon State University, Corvallis, OR 97331
| | - U.T. Iwaniec
- Department of Nutrition and Exercise Sciences, Oregon State University, Corvallis, OR 97331
- Corresponding author: Urszula T. Iwaniec, Ph.D., Department of Nutrition and Exercise Sciences, 108 Milam Hall, Oregon State University, Corvallis, OR 97331, Tel: 541-737-9925, Fax: 541-737-6914,
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Cao JJ, Sun L, Gao H. Diet-induced obesity alters bone remodeling leading to decreased femoral trabecular bone mass in mice. Ann N Y Acad Sci 2010; 1192:292-7. [PMID: 20392249 DOI: 10.1111/j.1749-6632.2009.05252.x] [Citation(s) in RCA: 104] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Obesity-derived body mass may be detrimental to bone health through not well-defined mechanisms. In this study we determined changes in bone structure and serum cytokines related to bone metabolism in diet-induced obese mice. Mice fed a high-fat diet (HFD) had higher serum tartrate-resistant acid phosphatase (TRAP) and leptin but lower osteocalcin concentrations than those fed the normal-fat diet. The HFD increased multinucleated TRAP-positive osteoclasts in bone marrow compared to the control diet. Despite being much heavier, mice fed the HFD had lower femoral bone volume, trabecular number, and connectivity density and higher trabecular separation than mice on the control diet. These findings suggest that obesity induced by a HFD increases bone resorption that may blunt any positive effects of increased body weight on bone.
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Affiliation(s)
- Jay J Cao
- USDA, Agricultural Research Service, Grand Forks Human Nutrition Research Center, Grand Forks, ND, USA.
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Mutabaruka MS, Aoulad Aissa M, Delalandre A, Lavigne M, Lajeunesse D. Local leptin production in osteoarthritis subchondral osteoblasts may be responsible for their abnormal phenotypic expression. Arthritis Res Ther 2010; 12:R20. [PMID: 20141628 PMCID: PMC2875652 DOI: 10.1186/ar2925] [Citation(s) in RCA: 90] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2009] [Revised: 01/08/2010] [Accepted: 02/08/2010] [Indexed: 12/21/2022] Open
Abstract
INTRODUCTION Leptin is a peptide hormone with a role in bone metabolism and rheumatic diseases. The subchondral bone tissue plays a prominent role in the pathophysiology of osteoarthritis (OA), related to abnormal osteoblast (Ob) differentiation. Although leptin promotes the differentiation of Ob under normal conditions, a role for leptin in OA Ob has not been demonstrated. Here we determined if endogenous leptin produced by OA Ob could be responsible for the expression of the abnormal phenotypic biomarkers observed in OA Ob. METHODS We prepared primary normal and OA Ob from subchondral bone of tibial plateaus removed for knee surgery of OA patients or at autopsy. We determined the production of leptin and of the long, biologically active, leptin receptors (OB-Rb) using reverse transcriptase-polymerase chain reaction, ELISA and Western blot analysis. We determined the effect of leptin on cell proliferation by BrdU incorporation and 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assays, and we determined by Western blot analysis phospho 42/44 MAPK (p42/44 Erk1/2) and phospho p38 levels. We then determined the effect of the addition of exogenous leptin, leptin receptor antagonists, inhibitors of leptin signaling or siRNA techniques on the phenotypic features of OA Ob. Phenotypic features of Ob were determined by measuring alkaline phosphatase activity (ALP), osteocalcin release (OC), collagen type 1 production (CICP) and of Transforming Growth Factor-beta1 (TGF-beta1). RESULTS Leptin expression was increased approximately five-fold and protein levels approximately two-fold in OA Ob compared to normal. Leptin stimulated its own expression and the expression of OB-Rb in OA Ob. Leptin dose-dependently stimulated cell proliferation of OA Ob and also increased phosphorylated p42/44 Erk1/2 and p38 levels. Inactivating antibodies against leptin reduced ALP, OC, CICP and TGF-beta1 levels in OA Ob. Tyrphostin (AG490) and piceatannol (Pce), inhibitors of leptin signaling, reproduced this effect. Inhibition of endogenous leptin levels using siRNA for leptin or inhibiting leptin signaling using siRNA for OB-Rb expression both reduced ALP and OC about 60%. Exogenous leptin addition stimulated ALP, yet this failed to further increase OC or CICP. CONCLUSIONS These results suggest that abnormal production of leptin by OA Ob could be responsible, in part, for the elevated levels of ALP, OC, collagen type 1 and TGF-beta1 observed in these cells compared to normal. Leptin also stimulated cell proliferation, and Erk 1/2 and p38 signaling. Taken together, these data suggest leptin could contribute to abnormal osteoblast function in OA.
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Affiliation(s)
- Marie-Solange Mutabaruka
- Unité de recherche en Arthose, Centre de recherche du Centre Hospitalier de l'Université de Montréal (CR-CHUM), Hôpital Notre-Dame, 1560 rue Sherbrooke Est, Montréal, QC H2L 4 M1, Canada.
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Iwaniec UT, Turner RT, Koo SI, Kaur R, Ho E, Wong CP, Bruno RS. Consumption of green tea extract results in osteopenia in growing male mice. J Nutr 2009; 139:1914-9. [PMID: 19710162 PMCID: PMC2744612 DOI: 10.3945/jn.109.107201] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Consumption of green tea may reduce body weight gain. Although many disorders are related to obesity, bone mass is positively correlated with body mass. Therefore, our purpose in this study was to determine the effects of green tea extract (GTE) on bone mass and architecture in rapidly growing lean [C57BL/6 wild type (WT)] and genetically obese, leptin-deficient (ob/ob) male mice. Five-week-old lean and ob/ob mice were assigned to diets containing GTE at 0, 1, or 2% for 6 wk. Femoral and lumbar vertebral bone volume and architecture were evaluated by micro-computed tomography (muCT). Following muCT analysis, femora were ashed to determine bone mineral content and density. Compared with WT mice, ob/ob mice had shorter femora (P < 0.001), lower femoral bone volume (P < 0.001), and lower femoral bone mineral content (P < 0.001), but higher cancellous bone volume in lumbar vertebrae (P < 001). Neither genotype nor treatment affected femoral bone mineral density, indicating normal mineralization. GTE consumption resulted in lower femur length, volume, mineral content, cortical volume, and cortical thickness (P < 0.001), as well as lower cancellous bone volume/tissue volume (P < 0.008) and trabecular thickness (P < 0.004) in lumbar vertebrae. The results indicate that leptin is not essential for the reduced gains in body weight and bone mass due to GTE in growing mice and suggest that consumption of large quantities of green tea may reduce the rate of bone accumulation during growth.
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Affiliation(s)
- Urszula T. Iwaniec
- Department of Nutrition and Exercise Sciences, Oregon State University, Corvallis, OR 97331; and Department of Nutritional Sciences, University of Connecticut, Storrs, CT 06269-4017
| | - Russell T. Turner
- Department of Nutrition and Exercise Sciences, Oregon State University, Corvallis, OR 97331; and Department of Nutritional Sciences, University of Connecticut, Storrs, CT 06269-4017
| | - Sung I. Koo
- Department of Nutrition and Exercise Sciences, Oregon State University, Corvallis, OR 97331; and Department of Nutritional Sciences, University of Connecticut, Storrs, CT 06269-4017
| | - Rouminder Kaur
- Department of Nutrition and Exercise Sciences, Oregon State University, Corvallis, OR 97331; and Department of Nutritional Sciences, University of Connecticut, Storrs, CT 06269-4017
| | - Emily Ho
- Department of Nutrition and Exercise Sciences, Oregon State University, Corvallis, OR 97331; and Department of Nutritional Sciences, University of Connecticut, Storrs, CT 06269-4017
| | - Carmen P. Wong
- Department of Nutrition and Exercise Sciences, Oregon State University, Corvallis, OR 97331; and Department of Nutritional Sciences, University of Connecticut, Storrs, CT 06269-4017
| | - Richard S. Bruno
- Department of Nutrition and Exercise Sciences, Oregon State University, Corvallis, OR 97331; and Department of Nutritional Sciences, University of Connecticut, Storrs, CT 06269-4017
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Taes YEC, Lapauw B, Vanbillemont G, Bogaert V, De Bacquer D, Zmierczak H, Goemaere S, Kaufman JM. Fat mass is negatively associated with cortical bone size in young healthy male siblings. J Clin Endocrinol Metab 2009; 94:2325-31. [PMID: 19401374 DOI: 10.1210/jc.2008-2501] [Citation(s) in RCA: 77] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
CONTEXT Body weight has been associated with bone mass and bone size through shared genetic determination and environmental influences. Whereas lean mass exerts a positive influence on bone size, the relationship between fat and bone remains unclear. OBJECTIVE The objective of the present study was to investigate the individual influence of fat mass and lean mass on volumetric bone density and size in young healthy male siblings at age of peak bone mass. DESIGN This was a cross-sectional, population-based sibling pair study. PARTICIPANTS A total of 677 men (25-45 yr) were included in this study with 296 independent pairs of brothers. MAIN OUTCOME MEASURES Areal and volumetric bone parameters were determined using dual-energy X-ray absorptiometry (DXA) and peripheral quantitative computed tomography (pQCT). Body composition was determined by DXA. Sex steroids, leptin, and adiponectin were determined by immunoassay. RESULTS Total and regional fat mass were found to be inversely associated with areal bone mass and bone size, independent from lean mass (radius periosteal circumference beta: -0.29 +/- 0.04; P < 0.001). Lean mass was positively associated with bone size but inversely with cortical density at both tibia and radius (P < 0.01). The negative association between total fat mass and bone size was independent from sex steroid concentrations. Leptin but not adiponectin was inversely associated with bone size, but this was no longer significant after adjustment for body fat. CONCLUSIONS Increased fat mass is associated with smaller bone size, challenging the view of a high bone mass index as a protective factor for osteoporosis, whereas lean mass was a consistent positive determinant of bone size.
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Affiliation(s)
- Youri E C Taes
- Department of Endocrinology, Ghent University Hospital, Belgium
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Kalra SP, Dube MG, Iwaniec UT. Leptin increases osteoblast-specific osteocalcin release through a hypothalamic relay. Peptides 2009; 30:967-73. [PMID: 19428775 PMCID: PMC2749976 DOI: 10.1016/j.peptides.2009.01.020] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/03/2008] [Revised: 01/21/2009] [Accepted: 01/23/2009] [Indexed: 12/31/2022]
Abstract
Enhanced long-term expression of leptin by gene therapy selectively in the hypothalamus, without leakage to the systemic circulation, abrogated skeletal abnormalities and reinstated weight and insulin-glucose homeostasis in leptin-deficient ob/ob mice. Whether increases in osteocalcin, a hormone produced by osteoblasts and known to play a role in bone growth and recently in glucose-insulin homeostasis, may link these benefits of central leptin was assessed. The effects of a single intraventricular injection of non-immunogenic, non-pathogenic recombinant adeno-associated virus vector encoding leptin gene (rAAV-lep) or green fluorescent protein gene (rAAV-GFP, control) were studied in three genotypes, wild type (wt), obese diabetic, hyperinsulinemic ob/ob and non-obese, diabetic insulinopenic Akita mice. Selective hypothalamic leptin expression with central rAAV-lep treatment decreased weight, fat mass, food intake, suppressed insulin levels in ob/ob and wt mice, and conferred euglycemia by suppressing blood glucose in all three genotypes. Contemporaneously, rAAV-lep treatment also augmented blood osteocalcin levels. In wt mice, osteocalcin rose by 51% and, whereas, basal osteocalcin levels in ob/ob and Akita mice were significantly lower as compared to those in wt mice (26% and 55%, respectively), gene therapy reinstated levels to the control range in ob/ob mice, and raised 40% above the wt range even in the absence of insulin in Akita mice. These findings demonstrate that the central beneficial effects of leptin on bone growth involve increased hypothalamic relay of signals that augment osteocalcin efflux from osteoblasts into the general circulation, a response that, in turn, may also modulate glucose-insulin and weight homeostasis.
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Affiliation(s)
- Satya P Kalra
- Department of Neuroscience, McKnight Brain Institute, College of Medicine, University of Florida, Gainesville, FL 32610-0244, United States.
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