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Graef F, Wei Y, Garbe A, Seemann R, Zenzes M, Tsitsilonis S, Duda GN, Zaslansky P. Increased cancellous bone mass accompanies decreased cortical bone mineral density and higher axial deformation in femurs of leptin-deficient obese mice. J Mech Behav Biomed Mater 2024; 160:106745. [PMID: 39317095 DOI: 10.1016/j.jmbbm.2024.106745] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2023] [Revised: 09/02/2024] [Accepted: 09/13/2024] [Indexed: 09/26/2024]
Abstract
INTRODUCTION Leptin is a pleiotropic hormone that regulates food intake and energy homeostasis with enigmatic effects on bone development. It is unclear if leptin promotes or inhibits bone growth. The aim of this study was to characterize the micro-architecture and mechanical competence of femur bones of leptin-deficient mice. MATERIALS AND METHODS Right femur bones of 15-week old C57BL/6 (n = 9) and leptin-deficient (ob/ob, n = 9) mice were analyzed. Whole bones were scanned using micro-CT and morphometric parameters of the cortex and trabeculae were assessed. Elastic moduli were determined from microindentations in midshaft cross-sections. Mineral densities were determined using quantitative backscatter scanning electron microscopy. 3D models of the distal femur metaphysis, cleared from trabecular bone, were meshed and used for finite element simulations of axial loading to identify straining differences between ob/ob and C57BL/6 controls. RESULTS Compared with C57BL/6 controls, ob/ob mice had significantly shorter bones. ob/ob mice showed significantly increased cancellous bone volume and trabecular thickness. qBEI quantified a ∼7% lower mineral density in ob/ob mice in the distal femur metaphysis. Indentation demonstrated a significantly reduced Young's modulus of 12.14 [9.67, 16.56 IQR] GPa for ob/ob mice compared to 23.12 [20.70, 26.57 IQR] GPa in C57BL/6 mice. FEA revealed greater deformation of cortical bone in ob/ob as compared to C57BL/6 mice. CONCLUSION Leptin deficient ob/ob mice have a softer cortical bone in the distal femur metaphysis but an excessive amount of cancellous bone, possibly as a response to increased deformation of the bones during axial loading. Both FEA and direct X-ray and electron microscopy imaging suggest that the morphology and micro-architecture of ob/ob mice have inferior biomechanical properties suggestive of a reduced mechanical competence.
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Affiliation(s)
- F Graef
- Charité - Universitätsmedizin Berlin, Center for Musculoskeletal Surgery, Germany; Julius Wolff Institute, Berlin Institute of Health at Charité - Universitätsmedizin Berlin, Germany.
| | - Y Wei
- Charité - Universitätsmedizin Berlin, Department of Operative and Preventive Dentistry, Germany; Julius Wolff Institute, Berlin Institute of Health at Charité - Universitätsmedizin Berlin, Germany.
| | - A Garbe
- Charité - Universitätsmedizin Berlin, Center for Musculoskeletal Surgery, Germany
| | - R Seemann
- Charité - Universitätsmedizin Berlin, Center for Musculoskeletal Surgery, Germany
| | - M Zenzes
- Charité - Universitätsmedizin Berlin, Department of Operative and Preventive Dentistry, Germany
| | - S Tsitsilonis
- Charité - Universitätsmedizin Berlin, Center for Musculoskeletal Surgery, Germany; Julius Wolff Institute, Berlin Institute of Health at Charité - Universitätsmedizin Berlin, Germany
| | - G N Duda
- Julius Wolff Institute, Berlin Institute of Health at Charité - Universitätsmedizin Berlin, Germany
| | - P Zaslansky
- Charité - Universitätsmedizin Berlin, Department of Operative and Preventive Dentistry, Germany.
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Qiu J, Liu J, Tian L, Yu J, Duan Q, Liu Y, Zhao W, Si H, Lu X, Zhang Q. Knockdown of LOX-1 ameliorates bone quality and generation of type H blood vessels in diabetic mice. Arch Biochem Biophys 2024; 752:109870. [PMID: 38141905 DOI: 10.1016/j.abb.2023.109870] [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: 07/29/2023] [Revised: 11/02/2023] [Accepted: 12/15/2023] [Indexed: 12/25/2023]
Abstract
Our previous studies have shown that lectin-like oxidized low-density lipoprotein receptor 1 (LOX-1) is expressed in liver sinusoidal endothelial cells, and oxidized low-density lipoprotein induces liver sinusoidal dysfunction and defenestration through the LOX-1/ROS/NF-kB pathway, revealing that LOX-1 can mediate liver sinusoidal barrier function, involved in the regulation of non-alcoholic fatty liver disease. Here, we investigated whether, in the context of bone metabolic diseases, LOX-1 could affect bone quality and type H blood vessels in diabetic mice. We used db/db mice as model and found that LOX-1 knockdown can ameliorate bone quality and type H blood vessel generation in db/db mice. This further verifies our hypothesis that LOX-1 is involved in the regulation of bone quality and type H blood vessel homeostasis, thus inhibiting osteoporosis progression in db/db mice.
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Affiliation(s)
- Jumei Qiu
- First Clinical School of Medicine, Gansu University of Chinese Medicine, Lanzhou, 730000, Gansu Province, China; Department of Geriatrics, Gansu Provincial Hospital, Lanzhou, 730000, Gansu Province, China
| | - Jing Liu
- Department of Geriatrics, Gansu Provincial Hospital, Lanzhou, 730000, Gansu Province, China; Clinical Research Center for Metabolic Disease, Lanzhou, 730000, Gansu Province, China
| | - Limin Tian
- First Clinical School of Medicine, Gansu University of Chinese Medicine, Lanzhou, 730000, Gansu Province, China; Department of Geriatrics, Gansu Provincial Hospital, Lanzhou, 730000, Gansu Province, China; Clinical Research Center for Metabolic Disease, Lanzhou, 730000, Gansu Province, China
| | - Jing Yu
- Department of Geriatrics, Gansu Provincial Hospital, Lanzhou, 730000, Gansu Province, China; Clinical Research Center for Metabolic Disease, Lanzhou, 730000, Gansu Province, China
| | - Qidang Duan
- First Clinical School of Medicine, Gansu University of Chinese Medicine, Lanzhou, 730000, Gansu Province, China; Department of Geriatrics, Gansu Provincial Hospital, Lanzhou, 730000, Gansu Province, China
| | - Yaqian Liu
- First Clinical School of Medicine, Gansu University of Chinese Medicine, Lanzhou, 730000, Gansu Province, China; Department of Geriatrics, Gansu Provincial Hospital, Lanzhou, 730000, Gansu Province, China
| | - Wenshu Zhao
- First Clinical School of Medicine, Gansu University of Chinese Medicine, Lanzhou, 730000, Gansu Province, China; Department of Geriatrics, Gansu Provincial Hospital, Lanzhou, 730000, Gansu Province, China
| | - Huiling Si
- First Clinical School of Medicine, Gansu University of Chinese Medicine, Lanzhou, 730000, Gansu Province, China; Department of Geriatrics, Gansu Provincial Hospital, Lanzhou, 730000, Gansu Province, China
| | - Xun Lu
- Ningxia Medical University, Yinchuan, 750000, Ningxia Hui Autonomous Region, China
| | - Qi Zhang
- First Clinical School of Medicine, Gansu University of Chinese Medicine, Lanzhou, 730000, Gansu Province, China; Department of Geriatrics, Gansu Provincial Hospital, Lanzhou, 730000, Gansu Province, China; Clinical Research Center for Metabolic Disease, Lanzhou, 730000, Gansu Province, China.
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Arora D, Taylor EA, King KB, Donnelly E. Increased tissue modulus and hardness in the TallyHO mouse model of early onset type 2 diabetes mellitus. PLoS One 2023; 18:e0287825. [PMID: 37418415 PMCID: PMC10328374 DOI: 10.1371/journal.pone.0287825] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2022] [Accepted: 06/14/2023] [Indexed: 07/09/2023] Open
Abstract
Individuals with type 2 diabetes mellitus (T2DM) have a higher fracture risk compared to those without T2DM despite having higher bone mineral density (BMD). Thus, T2DM may alter other aspects of resistance to fracture beyond BMD such as bone geometry, microarchitecture, and tissue material properties. We characterized the skeletal phenotype and assessed the effects of hyperglycemia on bone tissue mechanical and compositional properties in the TallyHO mouse model of early-onset T2DM using nanoindentation and Raman spectroscopy. Femurs and tibias were harvested from male TallyHO and C57Bl/6J mice at 26 weeks of age. The minimum moment of inertia assessed by micro-computed tomography was smaller (-26%) and cortical porosity was greater (+490%) in TallyHO femora compared to controls. In three-point bending tests to failure, the femoral ultimate moment and stiffness did not differ but post-yield displacement was lower (-35%) in the TallyHO mice relative to that in C57Bl/6J age-matched controls after adjusting for body mass. The cortical bone in the tibia of TallyHO mice was stiffer and harder, as indicated by greater mean tissue nanoindentation modulus (+22%) and hardness (+22%) compared to controls. Raman spectroscopic mineral:matrix ratio and crystallinity were greater in TallyHO tibiae than in C57Bl/6J tibiae (mineral:matrix +10%, p < 0.05; crystallinity +0.41%, p < 0.10). Our regression model indicated that greater values of crystallinity and collagen maturity were associated with reduced ductility observed in the femora of the TallyHO mice. The maintenance of structural stiffness and strength of TallyHO mouse femora despite reduced geometric resistance to bending could potentially be explained by increased tissue modulus and hardness, as observed at the tibia. Finally, with worsening glycemic control, tissue hardness and crystallinity increased, and bone ductility decreased in TallyHO mice. Our study suggests that these material factors may be sentinels of bone embrittlement in adolescents with T2DM.
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Affiliation(s)
- Daksh Arora
- Department of Materials Science and Engineering, Cornell University, Ithaca, New York, United States of America
| | - Erik A. Taylor
- Sibley School of Mechanical and Aerospace Engineering, Cornell University, Ithaca, New York, United States of America
| | - Karen B. King
- Department of Orthopedics, University of Colorado School of Medicine, Aurora, Colorado, United States of America
| | - Eve Donnelly
- Department of Materials Science and Engineering, Cornell University, Ithaca, New York, United States of America
- Research Institute, Hospital for Special Surgery, New York, New York, United States of America
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Villanueva-Carmona T, Cedó L, Madeira A, Ceperuelo-Mallafré V, Rodríguez-Peña MM, Núñez-Roa C, Maymó-Masip E, Repollés-de-Dalmau M, Badia J, Keiran N, Mirasierra M, Pimenta-Lopes C, Sabadell-Basallote J, Bosch R, Caubet L, Escolà-Gil JC, Fernández-Real JM, Vilarrasa N, Ventura F, Vallejo M, Vendrell J, Fernández-Veledo S. SUCNR1 signaling in adipocytes controls energy metabolism by modulating circadian clock and leptin expression. Cell Metab 2023; 35:601-619.e10. [PMID: 36977414 DOI: 10.1016/j.cmet.2023.03.004] [Citation(s) in RCA: 18] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/06/2022] [Revised: 11/21/2022] [Accepted: 03/03/2023] [Indexed: 03/30/2023]
Abstract
Adipose tissue modulates energy homeostasis by secreting leptin, but little is known about the factors governing leptin production. We show that succinate, long perceived as a mediator of immune response and lipolysis, controls leptin expression via its receptor SUCNR1. Adipocyte-specific deletion of Sucnr1 influences metabolic health according to nutritional status. Adipocyte Sucnr1 deficiency impairs leptin response to feeding, whereas oral succinate mimics nutrient-related leptin dynamics via SUCNR1. SUCNR1 activation controls leptin expression via the circadian clock in an AMPK/JNK-C/EBPα-dependent manner. Although the anti-lipolytic role of SUCNR1 prevails in obesity, its function as a regulator of leptin signaling contributes to the metabolically favorable phenotype in adipocyte-specific Sucnr1 knockout mice under standard dietary conditions. Obesity-associated hyperleptinemia in humans is linked to SUCNR1 overexpression in adipocytes, which emerges as the major predictor of adipose tissue leptin expression. Our study establishes the succinate/SUCNR1 axis as a metabolite-sensing pathway mediating nutrient-related leptin dynamics to control whole-body homeostasis.
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Affiliation(s)
- Teresa Villanueva-Carmona
- Department of Endocrinology and Nutrition, Research Unit, Institut d'Investigació Sanitària Pere Virgili (IISPV), Hospital Universitari de Tarragona Joan XXIII, Tarragona 43005, Spain; CIBER de Diabetes y Enfermedades Metabólicas Asociadas (CIBERDEM), Instituto de Salud Carlos III, Madrid 28029, Spain
| | - Lídia Cedó
- Department of Endocrinology and Nutrition, Research Unit, Institut d'Investigació Sanitària Pere Virgili (IISPV), Hospital Universitari de Tarragona Joan XXIII, Tarragona 43005, Spain; CIBER de Diabetes y Enfermedades Metabólicas Asociadas (CIBERDEM), Instituto de Salud Carlos III, Madrid 28029, Spain
| | - Ana Madeira
- Department of Endocrinology and Nutrition, Research Unit, Institut d'Investigació Sanitària Pere Virgili (IISPV), Hospital Universitari de Tarragona Joan XXIII, Tarragona 43005, Spain; CIBER de Diabetes y Enfermedades Metabólicas Asociadas (CIBERDEM), Instituto de Salud Carlos III, Madrid 28029, Spain
| | - Victòria Ceperuelo-Mallafré
- Department of Endocrinology and Nutrition, Research Unit, Institut d'Investigació Sanitària Pere Virgili (IISPV), Hospital Universitari de Tarragona Joan XXIII, Tarragona 43005, Spain; CIBER de Diabetes y Enfermedades Metabólicas Asociadas (CIBERDEM), Instituto de Salud Carlos III, Madrid 28029, Spain; Department of Medicine and Surgery, Universitat Rovira i Virgili (URV), Reus 43201, Spain
| | - M-Mar Rodríguez-Peña
- Department of Endocrinology and Nutrition, Research Unit, Institut d'Investigació Sanitària Pere Virgili (IISPV), Hospital Universitari de Tarragona Joan XXIII, Tarragona 43005, Spain; CIBER de Diabetes y Enfermedades Metabólicas Asociadas (CIBERDEM), Instituto de Salud Carlos III, Madrid 28029, Spain
| | - Catalina Núñez-Roa
- Department of Endocrinology and Nutrition, Research Unit, Institut d'Investigació Sanitària Pere Virgili (IISPV), Hospital Universitari de Tarragona Joan XXIII, Tarragona 43005, Spain; CIBER de Diabetes y Enfermedades Metabólicas Asociadas (CIBERDEM), Instituto de Salud Carlos III, Madrid 28029, Spain
| | - Elsa Maymó-Masip
- Department of Endocrinology and Nutrition, Research Unit, Institut d'Investigació Sanitària Pere Virgili (IISPV), Hospital Universitari de Tarragona Joan XXIII, Tarragona 43005, Spain; CIBER de Diabetes y Enfermedades Metabólicas Asociadas (CIBERDEM), Instituto de Salud Carlos III, Madrid 28029, Spain
| | - Maria Repollés-de-Dalmau
- Department of Endocrinology and Nutrition, Research Unit, Institut d'Investigació Sanitària Pere Virgili (IISPV), Hospital Universitari de Tarragona Joan XXIII, Tarragona 43005, Spain; CIBER de Diabetes y Enfermedades Metabólicas Asociadas (CIBERDEM), Instituto de Salud Carlos III, Madrid 28029, Spain; Department of Medicine and Surgery, Universitat Rovira i Virgili (URV), Reus 43201, Spain
| | - Joan Badia
- Institut d'Oncologia de la Catalunya Sud, Hospital Universitari Sant Joan de Reus, IISPV, Reus 43204, Spain
| | - Noelia Keiran
- Department of Endocrinology and Nutrition, Research Unit, Institut d'Investigació Sanitària Pere Virgili (IISPV), Hospital Universitari de Tarragona Joan XXIII, Tarragona 43005, Spain; CIBER de Diabetes y Enfermedades Metabólicas Asociadas (CIBERDEM), Instituto de Salud Carlos III, Madrid 28029, Spain
| | - Mercedes Mirasierra
- CIBER de Diabetes y Enfermedades Metabólicas Asociadas (CIBERDEM), Instituto de Salud Carlos III, Madrid 28029, Spain; Instituto de Investigaciones Biomédicas Alberto Sols, Consejo Superior de Investigaciones Científicas/Universidad Autónoma de Madrid (CSIC/UAM), Madrid 28029, Spain
| | - Carolina Pimenta-Lopes
- Departament de Ciències Fisiològiques, Universitat de Barcelona, IDIBELL, Hospitalet de Llobregat, Barcelona 08907, Spain
| | - Joan Sabadell-Basallote
- Department of Endocrinology and Nutrition, Research Unit, Institut d'Investigació Sanitària Pere Virgili (IISPV), Hospital Universitari de Tarragona Joan XXIII, Tarragona 43005, Spain; CIBER de Diabetes y Enfermedades Metabólicas Asociadas (CIBERDEM), Instituto de Salud Carlos III, Madrid 28029, Spain
| | - Ramón Bosch
- Department of Pathology, Oncological Pathology and Bioinformatics Research Group, Hospital de Tortosa Verge de la Cinta, IISPV, Tortosa 43500, Spain
| | - Laura Caubet
- General and Digestive Surgery Service, Hospital Sant Pau i Santa Tecla, Institut d'Investigació Sanitària Pere Virgili, Tarragona 43003, Spain
| | - Joan Carles Escolà-Gil
- CIBER de Diabetes y Enfermedades Metabólicas Asociadas (CIBERDEM), Instituto de Salud Carlos III, Madrid 28029, Spain; Institut d'Investigacions Biomèdiques (IIB) Sant Pau, Barcelona 08041, Spain; Departament de Bioquímica i Biologia Molecular, Universitat Autònoma de Barcelona, Cerdanyola del Vallès, Barcelona 08193, Spain
| | - José-Manuel Fernández-Real
- Department of Diabetes, Endocrinology and Nutrition, Institut d'Investigació Biomèdica de Girona (IdIBGi), Salt 17190, Spain; CIBER Fisiopatología de la Obesidad y Nutrición (CB06/03/010), Instituto de Salud Carlos III, Madrid 28029, Spain; Department of Medical Sciences, School of Medicine, University of Girona, Girona 17004, Spain
| | - Nuria Vilarrasa
- CIBER de Diabetes y Enfermedades Metabólicas Asociadas (CIBERDEM), Instituto de Salud Carlos III, Madrid 28029, Spain; Department of Endocrinology and Nutrition, Hospital Universitari Bellvitge - IDIBELL, Hospitalet de Llobregat, Barcelona 08907, Spain
| | - Francesc Ventura
- Departament de Ciències Fisiològiques, Universitat de Barcelona, IDIBELL, Hospitalet de Llobregat, Barcelona 08907, Spain
| | - Mario Vallejo
- CIBER de Diabetes y Enfermedades Metabólicas Asociadas (CIBERDEM), Instituto de Salud Carlos III, Madrid 28029, Spain; Instituto de Investigaciones Biomédicas Alberto Sols, Consejo Superior de Investigaciones Científicas/Universidad Autónoma de Madrid (CSIC/UAM), Madrid 28029, Spain
| | - Joan Vendrell
- Department of Endocrinology and Nutrition, Research Unit, Institut d'Investigació Sanitària Pere Virgili (IISPV), Hospital Universitari de Tarragona Joan XXIII, Tarragona 43005, Spain; CIBER de Diabetes y Enfermedades Metabólicas Asociadas (CIBERDEM), Instituto de Salud Carlos III, Madrid 28029, Spain; Department of Medicine and Surgery, Universitat Rovira i Virgili (URV), Reus 43201, Spain
| | - Sonia Fernández-Veledo
- Department of Endocrinology and Nutrition, Research Unit, Institut d'Investigació Sanitària Pere Virgili (IISPV), Hospital Universitari de Tarragona Joan XXIII, Tarragona 43005, Spain; CIBER de Diabetes y Enfermedades Metabólicas Asociadas (CIBERDEM), Instituto de Salud Carlos III, Madrid 28029, Spain.
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Chen B, He Q, Yang J, Pan Z, Xiao J, Chen W, Chi W, Li M, Li S, Zeng J, Chen C, Wang F, Pang X, Yi Y, Tu H, Wang H, Chen P. Metformin suppresses Oxidative Stress induced by High Glucose via Activation of the Nrf2/HO-1 Signaling Pathway in Type 2 Diabetic Osteoporosis. Life Sci 2022; 312:121092. [PMID: 36279968 DOI: 10.1016/j.lfs.2022.121092] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2022] [Revised: 10/10/2022] [Accepted: 10/13/2022] [Indexed: 11/07/2022]
Abstract
BACKGROUND Metformin (MET) is widely used as a first-line hypoglycemic agent for the treatment of type 2 diabetes mellitus (T2DM) and was also confirmed to have a therapeutic effect on type 2 diabetic osteoporosis (T2DOP). However, the potential mechanisms of MET in the treatment of T2DOP are unclear. OBJECTIVE To clarify the effect of MET in T2DOP and to explore the potential mechanism of MET in the treatment of T2DOP. METHODS In vitro, we used MC3T3-E1 cells to study the effects of MET on osteogenic differentiation and anti-oxidative stress injury in a high glucose (Glucose 25 mM) environment. In vivo, we directly used db/db mice as a T2DOP model and assessed the osteoprotective effects of MET by Micro CT and histological analysis. RESULTS In vitro, we found that MET increased ALP activity in MC3T3-E1 cells in a high-glucose environment, promoted the formation of bone mineralized nodules, and upregulated the expression of the osteogenesis-related transcription factors RUNX2, Osterix, and COL1A1-related genes. In addition, MET was able to reduce high glucose-induced reactive oxygen species (ROS) production. In studies on the underlying mechanisms, we found that MET activated the Nrf2/HO-1 signaling pathway and alleviated high-glucose-induced oxidative stress injury. In vivo results showed that MET reduced bone loss and bone microarchitecture destruction in db/db mice. CONCLUSION Our results suggest that MET can activate the Nrf2/HO-1 signaling pathway to regulate the inhibition of osteogenic differentiation induced by high glucose thereby protecting T2DOP.
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Affiliation(s)
- Bohao Chen
- 1st School of Medicine, Guangzhou University of Chinese Medicine, 12 Jichang Road, Baiyun Area, Guangzhou 510405, PR China; The Laboratory of Orthopaedics and Traumatology of Lingnan Medical Research Center, Guangzhou University of Chinese Medicine, Guangzhou 510405, PR China
| | - Qi He
- 1st School of Medicine, Guangzhou University of Chinese Medicine, 12 Jichang Road, Baiyun Area, Guangzhou 510405, PR China; The Laboratory of Orthopaedics and Traumatology of Lingnan Medical Research Center, Guangzhou University of Chinese Medicine, Guangzhou 510405, PR China
| | - Junzheng Yang
- 1st School of Medicine, Guangzhou University of Chinese Medicine, 12 Jichang Road, Baiyun Area, Guangzhou 510405, PR China; The Laboratory of Orthopaedics and Traumatology of Lingnan Medical Research Center, Guangzhou University of Chinese Medicine, Guangzhou 510405, PR China
| | - Zhaofeng Pan
- 1st School of Medicine, Guangzhou University of Chinese Medicine, 12 Jichang Road, Baiyun Area, Guangzhou 510405, PR China; The Laboratory of Orthopaedics and Traumatology of Lingnan Medical Research Center, Guangzhou University of Chinese Medicine, Guangzhou 510405, PR China
| | - Jiacong Xiao
- 1st School of Medicine, Guangzhou University of Chinese Medicine, 12 Jichang Road, Baiyun Area, Guangzhou 510405, PR China; The Laboratory of Orthopaedics and Traumatology of Lingnan Medical Research Center, Guangzhou University of Chinese Medicine, Guangzhou 510405, PR China
| | - Weijian Chen
- Guangdong Second Traditional Chinese Medicine Hospital, Guangzhou University of Chinese Medicine, Guangzhou 510405, PR China
| | - Weijin Chi
- 1st School of Medicine, Guangzhou University of Chinese Medicine, 12 Jichang Road, Baiyun Area, Guangzhou 510405, PR China; The Laboratory of Orthopaedics and Traumatology of Lingnan Medical Research Center, Guangzhou University of Chinese Medicine, Guangzhou 510405, PR China
| | - Miao Li
- 1st School of Medicine, Guangzhou University of Chinese Medicine, 12 Jichang Road, Baiyun Area, Guangzhou 510405, PR China; The Laboratory of Orthopaedics and Traumatology of Lingnan Medical Research Center, Guangzhou University of Chinese Medicine, Guangzhou 510405, PR China
| | - Shaocong Li
- 1st School of Medicine, Guangzhou University of Chinese Medicine, 12 Jichang Road, Baiyun Area, Guangzhou 510405, PR China; The Laboratory of Orthopaedics and Traumatology of Lingnan Medical Research Center, Guangzhou University of Chinese Medicine, Guangzhou 510405, PR China
| | - Jiaxu Zeng
- 1st School of Medicine, Guangzhou University of Chinese Medicine, 12 Jichang Road, Baiyun Area, Guangzhou 510405, PR China; The Laboratory of Orthopaedics and Traumatology of Lingnan Medical Research Center, Guangzhou University of Chinese Medicine, Guangzhou 510405, PR China
| | - Chuyi Chen
- 1st School of Medicine, Guangzhou University of Chinese Medicine, 12 Jichang Road, Baiyun Area, Guangzhou 510405, PR China; The Laboratory of Orthopaedics and Traumatology of Lingnan Medical Research Center, Guangzhou University of Chinese Medicine, Guangzhou 510405, PR China
| | - FanChen Wang
- 1st School of Medicine, Guangzhou University of Chinese Medicine, 12 Jichang Road, Baiyun Area, Guangzhou 510405, PR China; The Laboratory of Orthopaedics and Traumatology of Lingnan Medical Research Center, Guangzhou University of Chinese Medicine, Guangzhou 510405, PR China
| | - Xinyuan Pang
- Department of Neurology and Neuroscience Center, The First Hospital of Jilin University, Changchun, China
| | - Yanzi Yi
- The Third Affiliated Medical College of Guangzhou University of Chinese Medicine, Guangzhou University of Chinese Medicine, Guangzhou 510405, PR China
| | - Haitao Tu
- Department of Orthopaedics, First Affiliated Hospital, Guangzhou University of Chinese Medicine, 12 Jichang Road, Baiyun Area, Guangzhou 510405, China
| | - Haibin Wang
- Department of Orthopaedics, First Affiliated Hospital, Guangzhou University of Chinese Medicine, 12 Jichang Road, Baiyun Area, Guangzhou 510405, China.
| | - Peng Chen
- Department of Orthopaedics, First Affiliated Hospital, Guangzhou University of Chinese Medicine, 12 Jichang Road, Baiyun Area, Guangzhou 510405, China.
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Abu-Kheit R, Kotev-Emeth S, Hiram-Bab S, Gabet Y, Savion N. S-allylmercapto- N-acetylcysteine protects bone cells from oxidation and improves femur microarchitecture in healthy and diabetic mice. Exp Biol Med (Maywood) 2022; 247:1489-1500. [PMID: 35658550 PMCID: PMC9493761 DOI: 10.1177/15353702221095047] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
Oxidative stress is involved in the deterioration of bone quality and mechanical strength in both diabetic and aging adults. Therefore, we studied the ability of the antioxidant compound, S-allylmercapto-N-acetylcysteine (ASSNAC) to protect bone marrow stromal cells (BMSCs) from advanced glycation end-products (AGEs) cytotoxicity and improve bone microarchitecture of adult healthy and obese/diabetic (db/db) female mice. ASSNAC effect on AGEs-treated cultured rat BMSCs was evaluated by Neutral Red and XTT cell survival and reactive oxygen species (ROS) level assays. Its effect on healthy (C57BL/6) and obese/diabetic (C57BLKS/J Leprdb+/+; db/db) female mice femur parameters, such as (1) number of adherent BMSCs, (2) percentage of CD73+/CD45- cells in bone marrow (BM), (3) glutathione level in BM cells, and (4) femur microarchitecture parameters by microcomputed tomography, was studied. ASSNAC treatment protected BMSCs by significantly decreasing AGEs-induced ROS production and increasing their cellular resistance to the cytotoxic effect of AGEs. ASSNAC treatment of healthy female mice (50 mg/kg/day; i.p.; age 12-20 weeks) significantly increased the number of BMSCs (+60%), CD73+/CD45- cells (+134%), and glutathione level (+110%) in the femur bone marrow. Furthermore, it increased the femur length (+3%), cortical diameter (+3%), and cortical areal moment of inertia (Ct.MOI; +10%) a surrogate for biomechanical strength. In db/db mice that demonstrated a compromised trabecular bone and growth plate microarchitecture, ASSNAC treatment restored the trabecular number (Tb.N, +29%), bone volume fraction (Tb.BV/TV, +130%), and growth plate primary spongiosa volumetric bone mineral density (PS-vBMD, +7%) and thickness (PS-Th, +18%). In conclusion, this study demonstrates that ASSNAC protects bone marrow cells from oxidative stress and may improve bone microarchitecture in adult healthy and diabetic female mice.
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Affiliation(s)
- Reem Abu-Kheit
- Department of Human Molecular Genetics and
Biochemistry and Goldschleger Eye Research Institute, Sackler Faculty of Medicine, Tel Aviv
University, Tel Aviv 6997801, Israel
| | - Shlomo Kotev-Emeth
- Department of Human Molecular Genetics and
Biochemistry and Goldschleger Eye Research Institute, Sackler Faculty of Medicine, Tel Aviv
University, Tel Aviv 6997801, Israel
| | - Sahar Hiram-Bab
- Department of Anatomy and Anthropology,
Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv 6997801, Israel
| | - Yankel Gabet
- Department of Anatomy and Anthropology,
Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv 6997801, Israel
| | - Naphtali Savion
- Department of Human Molecular Genetics and
Biochemistry and Goldschleger Eye Research Institute, Sackler Faculty of Medicine, Tel Aviv
University, Tel Aviv 6997801, Israel;,Naphtali Savion.
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7
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Broz K, Walk RE, Tang SY. Complications in the spine associated with type 2 diabetes: The role of advanced glycation end-products. MEDICINE IN NOVEL TECHNOLOGY AND DEVICES 2021; 11. [PMID: 35992525 PMCID: PMC9390092 DOI: 10.1016/j.medntd.2021.100065] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Type 2 diabetes mellitus (T2D) is an increasingly prevalent disease with numerous comorbidities including many in the spine. T2D is strongly linked with vertebral fractures, intervertebral disc (IVD) degeneration, and severe chronic spinal pain. Yet the causative mechanism for these musculoskeletal impairments remains unclear. The chronic hyperglycemic state in T2D promotes the formation of advanced glycation end-products (AGEs) in tissues, and the accumulation of AGEs may play a role in musculoskeletal complications by modifying the extracellular matrix, impairing cellular homeostasis, and perpetuating an inflammatory cascade via its receptor (RAGE). The AGE and RAGE associated alterations in extracellular matrix composition and morphological features of the vertebral bodies and IVDs are likely contributors to the incidence and severity of spinal pathologies in T2D. This review will broadly examine the effects of AGEs on tissues in the spine in the context of T2D, with an emphasis on the changes in the vertebrae and the IVD. Along with the clinical and epidemiological findings, we will provide an overview of preclinical rodent models of T2D that exhibit deficits in the IVD and vertebral bone. Elucidating the role of AGEs and RAGE will be crucial for understanding the disease mechanisms and translation therapies of musculoskeletal pathologies in T2D.
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Affiliation(s)
- Kaitlyn Broz
- Institute of Material Science and Engineering, Washington University in St. Louis, St. Louis, MO, USA
| | - Remy E. Walk
- Department of Biomedical Engineering, Washington University in St. Louis, St. Louis, MO, USA
| | - Simon Y. Tang
- Institute of Material Science and Engineering, Washington University in St. Louis, St. Louis, MO, USA
- Department of Biomedical Engineering, Washington University in St. Louis, St. Louis, MO, USA
- Department of Orthopaedic Surgery, Washington University in St. Louis, St. Louis, MO, USA
- Corresponding author. Department of Orthopaedic Surgery, Washington University in St. Louis, School of Medicine, 660 S. Euclid Avenue, Campus Box 8233, St. Louis, MO, 63110, USA. (S.Y. Tang)
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8
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Turner RT, Wong CP, Fosse KM, Branscum AJ, Iwaniec UT. Caloric Restriction and Hypothalamic Leptin Gene Therapy Have Differential Effects on Energy Partitioning in Adult Female Rats. Int J Mol Sci 2021; 22:ijms22136789. [PMID: 34202651 PMCID: PMC8269114 DOI: 10.3390/ijms22136789] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2021] [Revised: 06/04/2021] [Accepted: 06/18/2021] [Indexed: 12/14/2022] Open
Abstract
Dieting is a common but often ineffective long-term strategy for preventing weight gain. Similar to humans, adult rats exhibit progressive weight gain. The adipokine leptin regulates appetite and energy expenditure but hyperleptinemia is associated with leptin resistance. Here, we compared the effects of increasing leptin levels in the hypothalamus using gene therapy with conventional caloric restriction on weight gain, food consumption, serum leptin and adiponectin levels, white adipose tissue, marrow adipose tissue, and bone in nine-month-old female Sprague-Dawley rats. Rats (n = 16) were implanted with a cannula in the 3rd ventricle of the hypothalamus and injected with a recombinant adeno-associated virus, encoding the rat gene for leptin (rAAV-Lep), and maintained on standard rat chow for 18 weeks. A second group (n = 15) was calorically-restricted to match the weight of the rAAV-Lep group. Both approaches prevented weight gain, and no differences in bone were detected. However, calorically-restricted rats consumed 15% less food and had lower brown adipose tissue Ucp-1 mRNA expression than rAAV-Lep rats. Additionally, calorically-restricted rats had higher abdominal white adipose tissue mass, higher serum leptin and adiponectin levels, and higher marrow adiposity. Caloric restriction and hypothalamic leptin gene therapy, while equally effective in preventing weight gain, differ in their effects on energy intake, energy expenditure, adipokine levels, and body composition.
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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; (R.T.T.); (C.P.W.); (K.M.F.)
| | - Carmen P. Wong
- Skeletal Biology Laboratory, School of Biological and Population Health Sciences, Oregon State University, Corvallis, OR 97331, USA; (R.T.T.); (C.P.W.); (K.M.F.)
| | - Kristina M. Fosse
- Skeletal Biology Laboratory, School of Biological and Population Health Sciences, Oregon State University, Corvallis, OR 97331, USA; (R.T.T.); (C.P.W.); (K.M.F.)
| | - Adam J. Branscum
- Biostatistics Program, School of Biological and Population Health Sciences, Oregon State University, Corvallis, OR 97331, USA;
| | - Urszula T. Iwaniec
- Skeletal Biology Laboratory, School of Biological and Population Health Sciences, Oregon State University, Corvallis, OR 97331, USA; (R.T.T.); (C.P.W.); (K.M.F.)
- Correspondence:
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9
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He Q, Yang J, Zhang G, Chen D, Zhang M, Pan Z, Wang Z, Su L, Zeng J, Wang B, Wang H, Chen P. Sanhuang Jiangtang tablet protects type 2 diabetes osteoporosis via AKT-GSK3β-NFATc1 signaling pathway by integrating bioinformatics analysis and experimental validation. JOURNAL OF ETHNOPHARMACOLOGY 2021; 273:113946. [PMID: 33647426 DOI: 10.1016/j.jep.2021.113946] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/02/2020] [Revised: 02/07/2021] [Accepted: 02/14/2021] [Indexed: 06/12/2023]
Abstract
ETHNOPHARMACOLOGICAL RELEVANCE Sanhuang Jiangtang tablet (SHJTT), has been widely used to treat type 2 diabetes mellitus (T2DM). However, the potential and mechanism of SHJTT in treating type 2 diabetes osteoporosis (T2DOP) has not been reported. AIM OF THE STUDY The aim of this work was to investigate the role and the underlying molecular mechanism of SHJTT in managing type 2 diabetes osteoporosis. MATERIALS AND METHODS The target genes of each component consisting of SHJTT were obtained by searching the ETCM database. The target genes of osteoporosis and diabetes were individually acquired by analyzing the DisGeNET and OMIM disease databases. Then the potential therapeutic genes were obtained from the intersection of the herbal medicine targets and the disease targets which were imported into the R and STRING platform for the analysis of GO terms, KEGG pathways and PPI network. The key modules of PPI network were constructed by Cytoscape software. Finally, leptin receptor deficiency (db/db) mice were confirmed as an animal model of type 2 diabetic osteoporosis (T2DOP) through phenotype assessment and the key genes of SHJTT against T2DOP were validated by quantitative real-time PCR (qRT-PCR). RESULTS A total of 786 target genes of SHJTT were obtained from ETCM. Simultaneously, a total of 3906 osteoporosis and type 2 diabetes associated targets were acquired from DisGeNET and OMIM databases. Then, 97 common targets were found by overlapping them. On the basis of the GO and KEGG enrichment analysis and PPI network, we found that the related pathway of SHJTT in type 2 diabetes osteoporosis was AKT-GSK3β-NFATc1 pathway which is tightly associated with osteoclast differentiation. The expression of key genes including Akt1, Mapk3, Gsk3β, Mmp9, Nfkb1 were significantly down-regulated by SHJTT in T2DOP mice (p < 0.05). CONCLUSIONS SHJTT had a protective effect on T2DOP via regulating AKT-GSK3β-NFATc1 signaling pathway. This study might provide a theoretical basis for the application of SHJTT for the treatment of type 2 diabetic osteoporosis.
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Affiliation(s)
- Qi He
- 1(st) School of Medicine, Guangzhou University of Chinese Medicine, 12 Jichang Road, Baiyun Area, Guangzhou, 510405, PR China; The Laboratory of Orthopaedics and Traumatology of Lingnan Medical Research Center, Guangzhou University of Chinese Medicine, Guangzhou, 510405, PR China
| | - Junzheng Yang
- 1(st) School of Medicine, Guangzhou University of Chinese Medicine, 12 Jichang Road, Baiyun Area, Guangzhou, 510405, PR China; The Laboratory of Orthopaedics and Traumatology of Lingnan Medical Research Center, Guangzhou University of Chinese Medicine, Guangzhou, 510405, PR China
| | - Gangyu Zhang
- 1(st) School of Medicine, Guangzhou University of Chinese Medicine, 12 Jichang Road, Baiyun Area, Guangzhou, 510405, PR China; The Laboratory of Orthopaedics and Traumatology of Lingnan Medical Research Center, Guangzhou University of Chinese Medicine, Guangzhou, 510405, PR China
| | - Delong Chen
- Department of Orthopaedic Surgery, Clifford Hospital, Jinan University, Guangzhou, 510006, PR China
| | - Meng Zhang
- Department of Orthopedics, Henan Provincial People's Hospital, People's Hospital of Zhengzhou University, People's Hospital of Henan University, Zhengzhou, Henan, 450003, PR China
| | - Zhaofeng Pan
- 1(st) School of Medicine, Guangzhou University of Chinese Medicine, 12 Jichang Road, Baiyun Area, Guangzhou, 510405, PR China; The Laboratory of Orthopaedics and Traumatology of Lingnan Medical Research Center, Guangzhou University of Chinese Medicine, Guangzhou, 510405, PR China
| | - Zihao Wang
- Queen's University Belfast, University Road, Belfast, Northen Ireland, BT7 1NN, United Kingdom
| | - Lijun Su
- 1(st) School of Medicine, Guangzhou University of Chinese Medicine, 12 Jichang Road, Baiyun Area, Guangzhou, 510405, PR China; The Laboratory of Orthopaedics and Traumatology of Lingnan Medical Research Center, Guangzhou University of Chinese Medicine, Guangzhou, 510405, PR China
| | - Jiaxu Zeng
- 1(st) School of Medicine, Guangzhou University of Chinese Medicine, 12 Jichang Road, Baiyun Area, Guangzhou, 510405, PR China; The Laboratory of Orthopaedics and Traumatology of Lingnan Medical Research Center, Guangzhou University of Chinese Medicine, Guangzhou, 510405, PR China
| | - Baohua Wang
- Department of Endocrinology, First Affiliated Hospital, Guangzhou University of Chinese Medicine, Guangzhou, 510405, PR China.
| | - Haibin Wang
- Department of Orthopaedics, First Affiliated Hospital, Guangzhou University of Chinese Medicine, 12 Jichang Road, Baiyun Area, Guangzho, 510405, PR China.
| | - Peng Chen
- Department of Orthopaedics, First Affiliated Hospital, Guangzhou University of Chinese Medicine, 12 Jichang Road, Baiyun Area, Guangzho, 510405, PR China.
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10
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Wang X, Xu J, Kang Q. Neuromodulation of bone: Role of different peptides and their interactions (Review). Mol Med Rep 2020; 23:32. [PMID: 33179112 PMCID: PMC7684869 DOI: 10.3892/mmr.2020.11670] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2020] [Accepted: 09/18/2020] [Indexed: 12/17/2022] Open
Abstract
Our understanding of the skeletal system has been expanded upon the recognition of several neural pathways that serve important roles in bone metabolism and skeletal homeostasis, as bone tissue is richly innervated. Considerable evidence provided by in vitro, animal and human studies have further elucidated the importance of a host of hormones and local factors, including neurotransmitters, in modulating bone metabolism and osteo-chondrogenic differentiation, both peripherally and centrally. Various cells of the musculoskeletal system not only express receptors for these neurotransmitters, but also influence their endogenous levels in the skeleton. As with a number of physiological systems in nature, a neuronal pathway regulating bone turnover will be neutralized by another pathway exerting an opposite effect. These neuropeptides are also critically involved in articular cartilage homeostasis and pathogenesis of degenerative joint disorders, such as osteoarthritis. In the present Review, data on the role of several neuronal populations in nerve-dependent skeletal metabolism is examined, and the molecular events involved are explored, which may reveal broader relationships between two apparently unrelated organs.
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Affiliation(s)
- Xiaoyu Wang
- Department of Orthopedic Surgery, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, Shanghai 200233, P.R. China
| | - Jia Xu
- Department of Orthopedic Surgery, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, Shanghai 200233, P.R. China
| | - Qinglin Kang
- Department of Orthopedic Surgery, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, Shanghai 200233, P.R. China
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11
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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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12
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Li X, Liu X, Wang Y, Cao F, Chen Z, Hu Z, Yu B, Feng H, Ba Z, Liu T, Li H, Jiang B, Huang Y, Li L, Wu D. Intervertebral disc degeneration in mice with type II diabetes induced by leptin receptor deficiency. BMC Musculoskelet Disord 2020; 21:77. [PMID: 32024487 PMCID: PMC7003448 DOI: 10.1186/s12891-020-3091-1] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/06/2018] [Accepted: 01/23/2020] [Indexed: 11/10/2022] Open
Abstract
Background The leptin receptor-deficient knockout (db/db) mouse is a well-established model for studying type II diabetes mellitus (T2DM). T2DM is an important risk factor of intervertebral disc degeneration (IVDD). Although the relationship between type I diabetes and IVDD has been reported by many studies, few studies have reported the effects of T2DM on IVDD in db/db mice model. Methods Mice were separated into 3 groups: wild-type (WT), db/db, and IGF-1 groups (leptin receptor-deficient mice were treated with insulin-like growth factor-1 (IGF-1). To observe the effects of T2DM and glucose-lowering treatment on IVDD, IGF-1 injection was used. The IVD phenotype was detected by H&E and safranin O fast green staining among db/db, WT and IGF-1 mice. The levels of blood glucose and weight in mice were also recorded. The changes in the mass of the trabecular bone in the fifth lumbar vertebra were documented by micro-computed tomography (micro-CT). Tunnel assays were used to detect cell apoptosis in each group. Results The weight of the mice were 27.68 ± 1.6 g in WT group, which was less than 57.56 ± 4.8 g in db/db group, and 52.17 ± 3.7 g in IGF-1 injected group (P < 0.05). The blood glucose levels were also significantly higher in the db/db mice group. T2DM caused by leptin receptor knockout showed an association with significantly decreased vertebral bone mass and increased IVDD when compared to WT mice. The db/db mice induced by leptin deletion showed a higher percentage of MMP3 expression as well as cell apoptosis in IVDD mice than WT mice (P < 0.05), while IGF-1 treatment reversed this situation (P < 0.05). Conclusions T2DM induced by leptin receptor knockout led to IVDD by increasing the levels of MMP3 and promoting cell apoptosis. IGF-1 treatment partially rescue the phenotype of IVDD induced by leptin receptor knockout.
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Affiliation(s)
- Xinhua Li
- Department of Spinal Surgery, Shanghai East Hospital, Tongji University School of Medicine, 150 Jimo Road, Shanghai, 200120, China
| | - Xiaoming Liu
- Department of Spinal Surgery, Shanghai East Hospital, Tongji University School of Medicine, 150 Jimo Road, Shanghai, 200120, China.,Department of Orthopedics, Tongren Hospital, Shanghai Jiao Tong University School of Medicine, 1111 XianXia Road, Shanghai, 200336, China
| | - Yiru Wang
- Department of endocrinology, Shanghai East Hospital, Tongji University School of Medicine, Shanghai, 200120, China
| | - Fuming Cao
- Department of endocrinology, Shanghai East Hospital, Tongji University School of Medicine, Shanghai, 200120, China
| | - Zhaoxiong Chen
- Department of Spinal Surgery, Shanghai East Hospital, Tongji University School of Medicine, 150 Jimo Road, Shanghai, 200120, China
| | - Zhouyang Hu
- Department of Spinal Surgery, Shanghai East Hospital, Tongji University School of Medicine, 150 Jimo Road, Shanghai, 200120, China
| | - Bin Yu
- Department of Spinal Surgery, Shanghai East Hospital, Tongji University School of Medicine, 150 Jimo Road, Shanghai, 200120, China
| | - Hang Feng
- Department of Spinal Surgery, Shanghai East Hospital, Tongji University School of Medicine, 150 Jimo Road, Shanghai, 200120, China
| | - Zhaoyu Ba
- Department of Spinal Surgery, Shanghai East Hospital, Tongji University School of Medicine, 150 Jimo Road, Shanghai, 200120, China
| | - Tao Liu
- Department of Spinal Surgery, Shanghai East Hospital, Tongji University School of Medicine, 150 Jimo Road, Shanghai, 200120, China
| | - Haoxi Li
- Department of Spinal Surgery, Shanghai East Hospital, Tongji University School of Medicine, 150 Jimo Road, Shanghai, 200120, China
| | - Bei Jiang
- Department of Spinal Surgery, Shanghai East Hospital, Tongji University School of Medicine, 150 Jimo Road, Shanghai, 200120, China
| | - Yufeng Huang
- Department of Spinal Surgery, Shanghai East Hospital, Tongji University School of Medicine, 150 Jimo Road, Shanghai, 200120, China.
| | - Lijun Li
- Department of Spinal Surgery, Shanghai East Hospital, Tongji University School of Medicine, 150 Jimo Road, Shanghai, 200120, China.
| | - Desheng Wu
- Department of Spinal Surgery, Shanghai East Hospital, Tongji University School of Medicine, 150 Jimo Road, Shanghai, 200120, China.
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13
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Abstract
PURPOSE OF REVIEW Individuals with type 1 and type 2 diabetes mellitus (T1DM, T2DM) have an increased risk of bone fracture compared to non-diabetic controls that is not explained by differences in BMD, BMI, or falls. Thus, bone tissue fracture resistance may be reduced in individuals with DM. The purpose of this review is to summarize work that analyzes the effects of T1DM and T2DM on bone tissue compositional and mechanical properties. RECENT FINDINGS Studies of clinical T2DM specimens revealed increased mineralization and advanced glycation endproduct (AGE) concentrations and significant relationships between mechanical performance and composition of cancellous bone. Specifically, in femoral cancellous tissue, compressive stiffness and strength increased with mineral content; and post-yield properties decreased with AGE concentration. In addition, cortical resistance to in vivo indentation (bone material strength index) was lower in patients with T2DM vs. age-matched non-diabetic controls, and this resistance decreased with worsening glycemic control. Recent studies on patients with T1DM and history of a prior fragility fracture found greater mineral content and concentrations of AGEs in iliac trabecular bone and correspondingly stiffer, harder bone at the nanosacle. Recent observational data showed greater AGE and mineral content in surgically retrieved bone from patients with T2DM vs. non-DM controls, consistent with reduced bone remodeling. Limited data on human T1DM bone tissue also showed higher mineral and AGE content in patients with prior fragility fractures compared to non-DM and non-fracture controls.
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MESH Headings
- Animals
- Biomechanical Phenomena
- Blood Glucose/metabolism
- Bone Density
- Bone Remodeling
- Bone and Bones/diagnostic imaging
- Bone and Bones/metabolism
- Bone and Bones/physiopathology
- Cancellous Bone/diagnostic imaging
- Cancellous Bone/metabolism
- Cancellous Bone/physiopathology
- Cortical Bone/diagnostic imaging
- Cortical Bone/metabolism
- Cortical Bone/physiopathology
- Diabetes Mellitus, Experimental/metabolism
- Diabetes Mellitus, Experimental/physiopathology
- Diabetes Mellitus, Type 1/epidemiology
- Diabetes Mellitus, Type 1/metabolism
- Diabetes Mellitus, Type 1/physiopathology
- Diabetes Mellitus, Type 2/epidemiology
- Diabetes Mellitus, Type 2/metabolism
- Diabetes Mellitus, Type 2/physiopathology
- Fractures, Bone/epidemiology
- Glycation End Products, Advanced/metabolism
- Humans
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Affiliation(s)
- Sashank Lekkala
- Department of Materials Science and Engineering, Cornell University, Ithaca, NY, USA
| | - Erik A Taylor
- Sibley School of Mechanical and Aerospace Engineering, Cornell University, Ithaca, NY, USA
| | - Heather B Hunt
- Department of Materials Science and Engineering, Cornell University, Ithaca, NY, USA
| | - Eve Donnelly
- Department of Materials Science and Engineering, Cornell University, Ithaca, NY, USA.
- Research Division, Hospital for Special Surgery, New York, NY, USA.
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14
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Mak IL, Lavery P, Agellon S, Rauch F, Murshed M, Weiler HA. Arachidonic acid exacerbates diet-induced obesity and reduces bone mineral content without impacting bone strength in growing male rats. J Nutr Biochem 2019; 73:108226. [PMID: 31520815 DOI: 10.1016/j.jnutbio.2019.108226] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2019] [Revised: 06/28/2019] [Accepted: 08/09/2019] [Indexed: 12/30/2022]
Abstract
Long-chain polyunsaturated fatty acids modulate bone mass and adipocyte metabolism. Arachidonic acid (AA, C20:4 n-6) is elevated in obesity and postulated to stimulate bone resorption. This study aimed to determine the effect of AA on bone mass, quality, and adiposity in diet-induced obesity during growth. Male Sprague-Dawley rats (n=42, 4-week) were randomized into groups fed a control diet (CTRL, AIN-93G), high-fat diet (HFD, 35% kcal fat) or HFD + AA (1% w/w diet) for 6 weeks. Body composition, bone mineral density and microarchitecture were measured using dual-energy X-ray absorptiometry and micro-computed tomography. Red blood cell fatty acid profile was measured with gas chromatography. Group differences were evaluated using repeated measures two-way analysis of variance with Tukey-Kramer post hoc testing. Total energy intake did not differ among diet groups. At week 6, HFD + AA had significantly greater body fat % (12%), body weight (6%) and serum leptin concentrations (125%) than CTRL, whereas visceral fat (mass and %, assessed with micro-computed tomography) was increased in both HFD and HFD + AA groups. HFD + AA showed reduced whole body bone mineral content and femur mid-diaphyseal cortical bone cross-sectional area than HFD and CTRL, without impairment in bone strength. Contrarily, HFD + AA had greater femur metaphyseal trabecular vBMD (35%) and bone volume fraction (5%) compared to controls. Inclusion of AA elevated leptin concentrations in male rats. The early manifestations of diet-induced obesity on bone mass were accelerated with AA. Studies of longer duration are needed to clarify the effect of AA on peak bone mass following growth cessation.
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Affiliation(s)
- Ivy L Mak
- School of Human Nutrition, McGill University, 21111 Lakeshore Road, Ste-Anne-de-Bellevue, QC, Canada H9X 3V9
| | - Paula Lavery
- School of Human Nutrition, McGill University, 21111 Lakeshore Road, Ste-Anne-de-Bellevue, QC, Canada H9X 3V9
| | - Sherry Agellon
- School of Human Nutrition, McGill University, 21111 Lakeshore Road, Ste-Anne-de-Bellevue, QC, Canada H9X 3V9
| | - Frank Rauch
- Shriners' Hospital for Children, 1003 Decarie Boulevard, Montreal, QC, Canada H4A 0A9
| | - Monzur Murshed
- Shriners' Hospital for Children, 1003 Decarie Boulevard, Montreal, QC, Canada H4A 0A9; Faculty of Dentistry, McGill University, 3640 rue University, Montreal, QC, Canada H3A 0C7
| | - Hope A Weiler
- School of Human Nutrition, McGill University, 21111 Lakeshore Road, Ste-Anne-de-Bellevue, QC, Canada H9X 3V9.
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15
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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: 109] [Impact Index Per Article: 18.2] [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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Philbrick KA, Branscum AJ, Wong CP, Turner RT, Iwaniec UT. Leptin Increases Particle-Induced Osteolysis in Female ob/ob Mice. Sci Rep 2018; 8:14790. [PMID: 30287858 PMCID: PMC6172200 DOI: 10.1038/s41598-018-33173-9] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2018] [Accepted: 09/17/2018] [Indexed: 11/09/2022] Open
Abstract
Particles generated from wear of prosthesis joint bearing surfaces induce inflammation-mediated periprosthetic bone resorption (osteolysis). Morbidly obese leptin-deficient ob/ob mice are resistant to polyethylene particle-induced bone loss, suggesting that leptin, a hormone produced by adipocytes that circulates in concentrations proportional to total body adiposity, increases osteolysis. To confirm that particles induce less osteolysis in leptin-deficient mice after controlling for cold stress (room temperature)-induced bone loss, ob/ob mice on a C57BL/6 (B6) background and colony B6 wildtype (WT) mice housed at thermoneutral temperature were randomized to control or particle treatment groups (N = 5/group). Polyethylene particles were implanted over calvaria and mice sacrificed 2 weeks later. Compared to particle-treated WT mice, particle-treated ob/ob mice had lower osteolysis score, less infiltration of immune cells, and less woven bone formation. To determine the role of leptin in particle-induced osteolysis, ob/ob mice were randomized into one of 4 groups (n = 6-8/group): (1) control, (2) particles, (3) particles + continuous leptin (osmotic pump, 6 μg/d), or (4) particles + intermittent leptin (daily injection, 40 μg/d). Leptin treatment increased particle-induced osteolysis in ob/ob mice, providing evidence that the adpiokine may play a role in inflammation-driven bone loss. Additional research is required to determine whether altering leptin levels within the physiological range results in corresponding changes in polyethylene-particle-induced osteolysis.
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Affiliation(s)
- Kenneth A Philbrick
- Skeletal Biology Laboratory, School of Biological and Population Health Sciences, Oregon State University, Corvallis, OR, 97331, USA
| | - Adam J Branscum
- Biostatistics Program, School of Biological and Population Health Sciences, Oregon State University, Corvallis, OR, 97331, USA
| | - Carmen P Wong
- Skeletal Biology Laboratory, School of Biological and Population Health Sciences, Oregon State University, Corvallis, OR, 97331, USA
| | - Russell T Turner
- Skeletal Biology Laboratory, School of Biological and Population Health Sciences, Oregon State University, Corvallis, OR, 97331, USA.,Center for Healthy Aging Research, Oregon State University, Corvallis, OR, 97331, USA
| | - Urszula T Iwaniec
- Skeletal Biology Laboratory, School of Biological and Population Health Sciences, Oregon State University, Corvallis, OR, 97331, USA. .,Center for Healthy Aging Research, Oregon State University, Corvallis, OR, 97331, USA.
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17
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McCabe IC, Fedorko A, Myers MG, Leinninger G, Scheller E, McCabe LR. Novel leptin receptor signaling mutants identify location and sex-dependent modulation of bone density, adiposity, and growth. J Cell Biochem 2018; 120:4398-4408. [PMID: 30269370 DOI: 10.1002/jcb.27726] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2018] [Accepted: 08/29/2018] [Indexed: 12/27/2022]
Abstract
Leptin, a hormone primarily produced by adipocytes, contributes to the regulation of bone health by modulating bone density, growth and adiposity. Upon leptin binding, multiple sites of the long form of the leptin receptor (LepRb) are phosphorylated to trigger activation of downstream signaling pathways. To address the role of LepRb-signaling pathways in bone health, we compared the effects of three LepRb mutations on bone density, adiposity, and growth in male and female mice. The ∆65 mutation, which lacks the known tyrosine phosphorylation sites, caused obesity and the most dramatic bone phenotype marked by excessive bone adiposity, osteoporosis, and decreased growth, consistent with the phenotype of db/db and ob/ob mice that fully lack leptin receptor signaling. Mutation of LepRb Tyr 1138 , which results in an inability to recruit and phosphorylate signal transducer and activator of transcription 3, also caused obesity, but bone loss and adiposity were more dominant in male mice and no growth defect was observed. In contrast, mutation of LepRb Tyr 985 , which blocks SHP2/SOCS3 recruitment to LepRb and contributes to leptin hypersensitivity, promoted increased femur bone density only in male mice, while marrow adiposity and bone growth were not affected. Additional analyses of vertebral trabecular bone volume indicate that only the Tyr 1138 mutant mice exhibit bone loss in vertebrae. Together, our findings suggest that the phosphorylation status of specific sites of the LepRb contribute to the sex- and location-dependent bone responses to leptin. Unraveling the mechanisms by which leptin responses are sex- and location-dependent can contribute to the development of uniquely targeted osteoporosis therapies.
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Affiliation(s)
- Ian C McCabe
- Department of Physiology, Michigan State University, East Lansing, Michigan
| | - Alyssa Fedorko
- Department of Physiology, Michigan State University, East Lansing, Michigan
| | - Martin G Myers
- Department of Molecular and Integrative Physiology, Division of Metabolism, Endocrinology and Diabetes, University of Michigan, Ann Arbor, Michigan.,Department of Internal Medicine, University of Michigan, Ann Arbor, Michigan
| | - Gina Leinninger
- Department of Physiology, Michigan State University, East Lansing, Michigan
| | - Erica Scheller
- Department of Medicine, Division of Bone and Mineral Diseases, Washington University, Saint Louis, Missouri
| | - Laura R McCabe
- Department of Physiology, Michigan State University, East Lansing, Michigan.,Department of Radiology, Michigan State University, East Lansing, Michigan.,Biomedical Imaging Research Center, Michigan State University, East Lansing, Michigan
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18
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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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19
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Minematsu A, Nishii Y, Imagita H, Sakata S. Long-Term Intake of Green Tea Extract Causes Mal-Conformation of Trabecular Bone Microarchitecture in Growing Rats. Calcif Tissue Int 2018; 102:358-367. [PMID: 29103160 DOI: 10.1007/s00223-017-0358-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/05/2017] [Accepted: 10/26/2017] [Indexed: 11/24/2022]
Abstract
The purpose of this study was to examine the effects of green tea extract (GTE) intake on bone structural and physiological properties, such as bone mass, trabecular bone microarchitecture, cortical bone geometry, and bone mechanical strength, in growing rats. Four-week-old male Wistar rats were divided into the following four groups: standard diet feeding for 85 days (S-CON) or 170 days (L-CON), and GTE diet feeding for 85 days (S-GTE) or 170 days (L-GTE). At the end of the experiment, in addition to measurement of circulating bone formation/resorption markers, bone mass, trabecular bone microarchitecture, and cortical bone geometry were analyzed in the left femur, and bone mechanical strength of the right femur was measured. There was no difference in all bone parameters between the S-CON and S-GTE groups. On the other hand, the L-GTE group showed the decrease in some trabecular bone mass/microarchitecture parameters and no change in cortical bone mass/geometry parameters compared with the L-CON group, and consequently the reduction in bone weight corrected by body weight. There was no difference in bone formation/resorption markers and bone mechanical strength between the S-CON and S-GTE groups and also between the L-CON and L-GTE groups. However, serum leptin levels were significantly lower in the L-GTE group than in the L-CON group. Thus, the long-term GTE intake had negative effects on bone, especially trabecular bone loss and microarchitecture mal-conformation, in growing rats.
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Affiliation(s)
- Akira Minematsu
- Department of Physical Therapy, Faculty of Health Science, Kio University, 4-2-2 Umaminaka, Koryo-cho, Kitakatsuragi-gun, Nara, 635-0832, Japan.
| | - Yasue Nishii
- Department of Physical Therapy, Faculty of Health Science, Kio University, 4-2-2 Umaminaka, Koryo-cho, Kitakatsuragi-gun, Nara, 635-0832, Japan
| | - Hidetaka Imagita
- Department of Physical Therapy, Faculty of Health Science, Kio University, 4-2-2 Umaminaka, Koryo-cho, Kitakatsuragi-gun, Nara, 635-0832, Japan
| | - Susumu Sakata
- Department of Physiology, Nara Medical University, 840 Shijou-cho, Kashihara, Nara, 634-8521, Japan
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20
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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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21
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The temporal expression of adipokines during spinal fusion. Spine J 2017. [PMID: 28647583 DOI: 10.1016/j.spinee.2017.06.019] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
BACKGROUND CONTEXT Adipokines are secreted by white adipose tissue and have been associated with fracture healing. Our goal was to report the temporal expression of adipokines during spinal fusion in an established rabbit model. PURPOSE Our goal was to report the temporal expression of adipokines during spinal fusion in an established rabbit model. STUDY DESIGN The study design included a laboratory animal model. METHODS New Zealand white rabbits were assigned to either sham surgery (n=2), unilateral posterior spinal fusion (n=14), or bilateral posterior spinal fusion (n=14). Rabbits were euthanized 1-6 and 10 weeks out from surgery. Fusion was evaluated by radiographs, manual palpation, and histology. Reverse transcription-polymerase chain reaction on the bone fusion mass catalogued the gene expression of leptin, adiponectin, resistin, and vascular endothelial growth factor (VEGF) at each time point. Results were normalized to the internal control gene, glyceraldehyde-3-phosphate dehydrogenase (GAPDH) (2^ΔCt), and control bone sites (2^ΔΔCt). Quantitative data were analyzed by two-factor analysis of variance (p<.05). RESULTS Manual palpation scores, radiograph scores, and histologic findings showed progression of boney fusion over time (p<.0003). The frequency of fusion by palpation after 4 weeks was 68.75%. Leptin expression in decortication and bone graft sites peaked at 5 weeks after the fusion procedure (p=.0143), adiponectin expression was greatest 1 week after surgery (p<.001), VEGF expression peaked at 4 weeks just after initial increases in leptin expression (p<.001), and resistin decreased precipitously 1 week after the fusion procedure (p<.001). CONCLUSIONS Leptin expression is likely associated with the maturation phase of bone fusion. Adiponectin and resistin may play a role early on during the fusion process. Our results suggest that leptin expression may be upstream of VEGF expression during spinal fusion, and both appear to play an important role in bone spinal fusion.
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22
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Li X, Shi S, Chen J, Zhong G, Li X, Liu Z. Leptin differentially regulates endochondral ossification in tibial and vertebral epiphyseal plates. Cell Biol Int 2017; 42:169-179. [PMID: 28980745 DOI: 10.1002/cbin.10882] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2017] [Accepted: 09/30/2017] [Indexed: 11/11/2022]
Abstract
Longitudinal bone growth is governed by a complex network of endocrine signals including leptin. In mouse, leptin deficiency leads to distinct phenotypes in bones of the limb and spine, suggesting the appendicular and axial skeletons are subject to differential regulation by leptin. We established primary cultures for the chondrocytes from tibial and vertebral epiphyseal plates. Cellular proliferation and apoptosis were analyzed for the chondrocytes that had been treated with various concentrations of leptin. Crucial factors for chondrocyte proliferation and differentiation, such as BMP7 and Wnt3, were measured in the cells treated with leptin alone or in combination with pharmacological inhibitors of STAT and ERK signaling pathways. Primary culture of tibial epiphyseal plate chondrocytes has greater proliferating capability compared with that of vertebral epiphyseal plate chondrocytes. Leptin could promote the proliferation of tibial epiphyseal plate chondrocytes, while its effect on vertebral epiphyseal plate chondrocytes was inhibitory. Consistently, apoptosis is inhibited in tibial but promoted in vertebral epiphyseal plate chondrocytes by leptin. Importantly, leptin differentially modulates chondrogenic signaling pathways in tibial and vertebral epiphyseal chondrocytes through STAT and ERK pathways. Leptin differentially regulates chondrogenic proliferation and differentiation in appendicular and axial regions of the skeletons. The signaling pathways in these two regions are also distinct and subject to differential regulation by leptin through the STAT pathway in tibial epiphyseal plate chondrocytes but through the ERK pathway in vertebral epiphyseal plate chondrocytes. Therefore, the regulation of leptin is multi-faceted in the distinct anatomical regions of the skeleton. Knowledge gained from this system will provide insights into the pathophysiological causes for the diseases related to bone development and metabolism.
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Affiliation(s)
- Xiaomiao Li
- Department of Orthopaedic, Ren Ji Hospital, School of Medicine, Shanghai Jiao Tong University, No. 160 Pujian Road, Shanghai, 200127, China
| | - Sheng Shi
- Department of Orthopaedic, Ren Ji Hospital, School of Medicine, Shanghai Jiao Tong University, No. 160 Pujian Road, Shanghai, 200127, China
| | - Jianwei Chen
- Department of Orthopaedic, Ren Ji Hospital, School of Medicine, Shanghai Jiao Tong University, No. 160 Pujian Road, Shanghai, 200127, China
| | - Guibin Zhong
- Department of Orthopaedic, Ren Ji Hospital, School of Medicine, Shanghai Jiao Tong University, No. 160 Pujian Road, Shanghai, 200127, China
| | - Xinfeng Li
- Department of Orthopaedic, Ren Ji Hospital, School of Medicine, Shanghai Jiao Tong University, No. 160 Pujian Road, Shanghai, 200127, China
| | - Zude Liu
- Department of Orthopaedic, Ren Ji Hospital, School of Medicine, Shanghai Jiao Tong University, No. 160 Pujian Road, Shanghai, 200127, China
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23
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Effects of low-intensity pulsed electromagnetic fields on bone microarchitecture, mechanical strength and bone turnover in type 2 diabetic db/db mice. Sci Rep 2017; 7:10834. [PMID: 28883516 PMCID: PMC5589741 DOI: 10.1038/s41598-017-11090-7] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2017] [Accepted: 08/17/2017] [Indexed: 01/06/2023] Open
Abstract
Type 2 diabetic patients have impaired bone quality, leading to increased fracture risk. Substantial evidence demonstrates that pulsed electromagnetic fields (PEMF) could resist osteopenia/osteoporosis induced by estrogen deficiency and disuse. However, the effects of PEMF on osteopenia/osteoporosis associated with diabetes, especially for more prevalent type 2 diabetes, remain poorly understood. We herein investigated the skeletal effects and mechanisms of PEMF (15 Hz, 20 Gs) on leptin receptor-deficient db/db mice with typical type 2 diabetic symptoms. Our µCT results showed that 12-week PEMF exposure significantly improved both cancellous and cortical bone microarchitecture in db/db mice. Three-point bending and biomechanical indentation testing demonstrated that PEMF improved whole-bone structural properties and tissue-level material properties in db/db mice. PEMF significantly promoted bone formation in db/db mice evidenced by increased serum osteocalcin and bone mineral apposition rate, whereas PEMF exerted no observable alteration in bone resorption. Real-time PCR showed that PEMF upregulated tibial gene expression of osteoblastogenesis-related of canonical Wnt/β-catenin signaling but not osteoclastogenesis-related RANKL-RANK signaling in db/db mice. Our findings demonstrate that PEMF improved bone quantity and quality with obvious anabolic activities in db/db mice, and imply that PEMF might become a clinically applicable treatment modality for improving bone quality in type 2 diabetic patients.
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24
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Yu B, Jiang K, Chen B, Wang H, Li X, Liu Z. Leptin differentially regulates chondrogenesis in mouse vertebral and tibial growth plates. BMC Musculoskelet Disord 2017; 18:235. [PMID: 28569158 PMCID: PMC5452289 DOI: 10.1186/s12891-017-1601-6] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/06/2016] [Accepted: 05/22/2017] [Indexed: 12/15/2022] Open
Abstract
BACKGROUND Leptin plays an important role in mediating chondrogenesis of limb growth plate. Previous studies suggest that bone structures and development of spine and limb are different. The expression of Ob-Rb, the gene that encodes leptin receptors, is vertebral and appendicular region-specific, suggesting the regulation of leptin on VGP and TGP chondrogenesis may be very different. The aim of the present study was to investigate the differential regulation of leptin on the chondrogenesis of vertebral growth plate (VGP) and tibial growth plate (TGP). METHODS We compared the VGP and TGP from wild type (C57BL/6) and leptin-deficient (ob/ob) mice. We then generated primary cultures of TGP and VGP chondrocytes. By treating the primary cells with different concentrations of leptin in vitro, we analyzed proliferation and apoptosis of the primary chondrocytes from TGP and VGP. We further measured expression of chondrogenic-related genes in these cells that had been incubated with different doses of leptin. RESULTS Leptin-deficient mice of 8-week-old had shorter tibial and longer vertebral lengths than the wide type mice. Disturbed columnar structure was observed for TGP but not for VGP. In primary chondrocyte cultures, leptin inhibited VGP chondrocyte proliferation but promoted their apoptosis. Collagen IIA and aggrecan mRNA, and the protein levels of proliferation- and chondrogenesis-related markers, including PCNA, Sox9, and Smad4, were downregulated by leptin in a dose-dependent manner. In contrast, leptin stimulated the proliferation and chondrogenic differentiation of TGP chondrocytes at physiological levels (i.e., 10 and 50 ng/mL) but not at high levels (i.e., 100 and 1000 ng/mL). CONCLUSION Leptin exerts a stimulatory effect on the proliferation and chondrogenic differentiation of the long bone growth plate but an inhibitory effect on the spine growth plate. The ongoing study will shed light on the regulatory mechanisms of leptin in bone development and metabolism.
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Affiliation(s)
- Bo Yu
- Department of Spine Surgery, Ren Ji Hospital, School of Medicine, Shanghai Jiao Tong University, 160 Pujian Rd, Shanghai, 200127, China
| | - Kaibiao Jiang
- Department of Spine Surgery, Ren Ji Hospital, School of Medicine, Shanghai Jiao Tong University, 160 Pujian Rd, Shanghai, 200127, China
| | - Bin Chen
- Department of Spine Surgery, Ren Ji Hospital, School of Medicine, Shanghai Jiao Tong University, 160 Pujian Rd, Shanghai, 200127, China
| | - Hantao Wang
- Department of Spine Surgery, Ren Ji Hospital, School of Medicine, Shanghai Jiao Tong University, 160 Pujian Rd, Shanghai, 200127, China
| | - Xinfeng Li
- Department of Spine Surgery, Ren Ji Hospital, School of Medicine, Shanghai Jiao Tong University, 160 Pujian Rd, Shanghai, 200127, China
| | - Zude Liu
- Department of Spine Surgery, Ren Ji Hospital, School of Medicine, Shanghai Jiao Tong University, 160 Pujian Rd, Shanghai, 200127, China.
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25
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McGee-Lawrence ME, Wenger KH, Misra S, Davis CL, Pollock NK, Elsalanty M, Ding K, Isales CM, Hamrick MW, Wosiski-Kuhn M, Arounleut P, Mattson MP, Cutler RG, Yu JC, Stranahan AM. Whole-Body Vibration Mimics the Metabolic Effects of Exercise in Male Leptin Receptor-Deficient Mice. Endocrinology 2017; 158:1160-1171. [PMID: 28323991 PMCID: PMC5460837 DOI: 10.1210/en.2016-1250] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/20/2016] [Accepted: 02/02/2017] [Indexed: 01/12/2023]
Abstract
Whole-body vibration (WBV) has gained attention as a potential exercise mimetic, but direct comparisons with the metabolic effects of exercise are scarce. To determine whether WBV recapitulates the metabolic and osteogenic effects of physical activity, we exposed male wild-type (WT) and leptin receptor-deficient (db/db) mice to daily treadmill exercise (TE) or WBV for 3 months. Body weights were analyzed and compared with WT and db/db mice that remained sedentary. Glucose and insulin tolerance testing revealed comparable attenuation of hyperglycemia and insulin resistance in db/db mice following TE or WBV. Both interventions reduced body weight in db/db mice and normalized muscle fiber diameter. TE or WBV also attenuated adipocyte hypertrophy in visceral adipose tissue and reduced hepatic lipid content in db/db mice. Although the effects of leptin receptor deficiency on cortical bone structure were not eliminated by either intervention, exercise and WBV increased circulating levels of osteocalcin in db/db mice. In the context of increased serum osteocalcin, the modest effects of TE and WBV on bone geometry, mineralization, and biomechanics may reflect subtle increases in osteoblast activity in multiple areas of the skeleton. Taken together, these observations indicate that WBV recapitulates the effects of exercise on metabolism in type 2 diabetes.
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MESH Headings
- Adipocytes/metabolism
- Adipocytes/pathology
- Animals
- Body Weight
- Diabetes Mellitus, Experimental/genetics
- Diabetes Mellitus, Experimental/metabolism
- Diabetes Mellitus, Experimental/therapy
- Diabetes Mellitus, Type 2/genetics
- Diabetes Mellitus, Type 2/metabolism
- Diabetes Mellitus, Type 2/therapy
- Energy Metabolism/genetics
- Male
- Mice
- Mice, Inbred C57BL
- Mice, Knockout
- Muscular Atrophy/genetics
- Muscular Atrophy/metabolism
- Muscular Atrophy/prevention & control
- Physical Conditioning, Animal/physiology
- Receptors, Leptin/genetics
- Vibration/therapeutic use
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Affiliation(s)
- Meghan E. McGee-Lawrence
- Department of Cellular Biology and Anatomy, Medical College of Georgia, Augusta University, Augusta, Georgia 30912
| | - Karl H. Wenger
- Department of Orthopedic Surgery, Medical College of Georgia, Augusta University, Augusta, Georgia 30912
| | - Sudipta Misra
- Department of Pediatrics, Gastroenterology Division, Medical College of Georgia, Augusta University, Augusta, Georgia 30912
| | - Catherine L. Davis
- Georgia Prevention Institute, Medical College of Georgia, Augusta University, Augusta, Georgia 30912
- Physiology Department, Medical College of Georgia, Augusta University, Augusta, Georgia 30912
| | - Norman K. Pollock
- Georgia Prevention Institute, Medical College of Georgia, Augusta University, Augusta, Georgia 30912
- Physiology Department, Medical College of Georgia, Augusta University, Augusta, Georgia 30912
| | - Mohammed Elsalanty
- Department of Oral Biology, Medical College of Georgia, Augusta University, Augusta, Georgia 30912
| | - Kehong Ding
- Department of Neuroscience and Regenerative Medicine, Medical College of Georgia, Augusta University, Augusta, Georgia 30912
| | - Carlos M. Isales
- Department of Neuroscience and Regenerative Medicine, Medical College of Georgia, Augusta University, Augusta, Georgia 30912
| | - Mark W. Hamrick
- Department of Cellular Biology and Anatomy, Medical College of Georgia, Augusta University, Augusta, Georgia 30912
| | - Marlena Wosiski-Kuhn
- Physiology Department, Medical College of Georgia, Augusta University, Augusta, Georgia 30912
| | - Phonepasong Arounleut
- Department of Cellular Biology and Anatomy, Medical College of Georgia, Augusta University, Augusta, Georgia 30912
| | - Mark P. Mattson
- Laboratory of Neurosciences, National Institute on Aging Intramural Research Program, Baltimore, Maryland 21224
| | - Roy G. Cutler
- Laboratory of Neurosciences, National Institute on Aging Intramural Research Program, Baltimore, Maryland 21224
| | - Jack C. Yu
- Department of Surgery, Plastic Surgery Division, Medical College of Georgia, Augusta University, Augusta, Georgia 30912
| | - Alexis M. Stranahan
- Department of Neuroscience and Regenerative Medicine, Medical College of Georgia, Augusta University, Augusta, Georgia 30912
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26
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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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27
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Pereira M, Gohin S, Roux JP, Fisher A, Cleasby ME, Mabilleau G, Chenu C. Exenatide Improves Bone Quality in a Murine Model of Genetically Inherited Type 2 Diabetes Mellitus. Front Endocrinol (Lausanne) 2017; 8:327. [PMID: 29209277 PMCID: PMC5701968 DOI: 10.3389/fendo.2017.00327] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/09/2017] [Accepted: 11/03/2017] [Indexed: 12/30/2022] Open
Abstract
Type 2 diabetes mellitus (T2DM) is associated with skeletal complications, including an increased risk of fractures. Reduced blood supply and bone strength may contribute to this skeletal fragility. We hypothesized that long-term administration of Exenatide, a glucagon-like peptide-1 receptor agonist, would improve bone architecture and strength of T2DM mice by increasing blood flow to bone, thereby stimulating bone formation. In this study, we used a model of obesity and severe T2DM, the leptin receptor-deficient db/db mouse to assess alterations in bone quality and hindlimb blood flow and to examine the beneficial effects of 4 weeks administration of Exenatide. As expected, diabetic mice showed marked alterations in bone structure, remodeling and strength, and basal vascular tone compared with lean mice. Exenatide treatment improved trabecular bone mass and architecture by increasing bone formation rate, but only in diabetic mice. Although there was no effect on hindlimb perfusion at the end of this treatment, Exenatide administration acutely increased tibial blood flow. While Exenatide treatment did not restore the impaired bone strength, intrinsic properties of the matrix, such as collagen maturity, were improved. The effects of Exenatide on in vitro bone formation were further investigated in primary osteoblasts cultured under high-glucose conditions, showing that Exenatide reversed the impairment in bone formation induced by glucose. In conclusion, Exenatide improves trabecular bone mass by increasing bone formation and could protect against the development of skeletal complications associated with T2DM.
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Affiliation(s)
- Marie Pereira
- Department of Comparative Biomedical Sciences, Royal Veterinary College, London, United Kingdom
- *Correspondence: Marie Pereira,
| | - Stephanie Gohin
- Department of Comparative Biomedical Sciences, Royal Veterinary College, London, United Kingdom
| | | | | | - Mark E. Cleasby
- Department of Comparative Biomedical Sciences, Royal Veterinary College, London, United Kingdom
| | - Guillaume Mabilleau
- GEROM-LHEA UPRES EA 4658, Institut de Biologie en Santé, Université d’Angers, Angers, France
| | - Chantal Chenu
- Department of Comparative Biomedical Sciences, Royal Veterinary College, London, United Kingdom
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28
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Rendina-Ruedy E, Smith BJ. Methodological considerations when studying the skeletal response to glucose intolerance using the diet-induced obesity model. BONEKEY REPORTS 2016; 5:845. [PMID: 27818742 PMCID: PMC5081001 DOI: 10.1038/bonekey.2016.71] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/29/2016] [Accepted: 08/24/2016] [Indexed: 01/22/2023]
Abstract
The prevalence of obesity and type 2 diabetes mellitus (T2DM) continues to rise, and as a result, research aimed at understanding the molecular basis for the co-morbidities has become an area of much scientific interest. Among the more recently recognized chronic complications of T2DM is the increased risk of fracture, especially hip fracture, that has been reported independent of bone mineral density (BMD). A widely used animal model to study how the development and progression of impaired glucose tolerance affect the skeleton has been the diet-induce obesity (DIO) model. As the name implies, this model employs the use of a version of high-fat diets to induce obesity and the subsequent metabolic perturbations that occur with T2DM. Although the model offers a number of advantages, the literature reveals some inconsistent results. Upon further review, discrepancies in the choice of the experimental high-fat diets and the control diets have become a point of major concern. The variability between diets and study design has made it difficult to compare data and results across studies. Therefore, this review aims to provide guidelines that should be employed when designing studies using DIO models of T2DM.
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Affiliation(s)
| | - Brenda J Smith
- Department of Nutritional Sciences, Oklahoma State University, Stillwater, OK, USA
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29
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Jing D, Luo E, Cai J, Tong S, Zhai M, Shen G, Wang X, Luo Z. Mechanical Vibration Mitigates the Decrease of Bone Quantity and Bone Quality of Leptin Receptor-Deficient Db/Db Mice by Promoting Bone Formation and Inhibiting Bone Resorption. J Bone Miner Res 2016; 31:1713-24. [PMID: 26990203 DOI: 10.1002/jbmr.2837] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/28/2015] [Revised: 03/02/2016] [Accepted: 03/14/2016] [Indexed: 02/06/2023]
Abstract
Leptin, a major hormonal product of adipocytes, is involved in regulating appetite and energy metabolism. Substantial studies have revealed the anabolic actions of leptin on skeletons and bone cells both in vivo and in vitro. Growing evidence has substantiated that leptin receptor-deficient db/db mice exhibit decreased bone mass and impaired bone microstructure despite several conflicting results previously reported. We herein systematically investigated bone microarchitecture, mechanical strength, bone turnover and its potential molecular mechanisms in db/db mice. More importantly, we also explored an effective approach for increasing bone mass in leptin receptor-deficient animals in an easy and noninvasive manner. Our results show that deterioration of trabecular and cortical bone microarchitecture and decreases of skeletal mechanical strength-including maximum load, yield load, stiffness, energy, tissue-level modulus and hardness-in db/db mice were significantly ameliorated by 12-week, whole-body vibration (WBV) with 0.5 g, 45 Hz via micro-computed tomography (μCT), three-point bending, and nanoindentation examinations. Serum biochemical analysis shows that WBV significantly decreased serum tartrate-resistant acid phosphatase 5b (TRACP5b) and CTx-1 levels and also mitigated the reduction of serum osteocalcin (OCN) in db/db mice. Bone histomorphometric analysis confirmed that decreased bone formation-lower mineral apposition rate, bone formation rate, and osteoblast numbers in cancellous bone-in db/db mice were suppressed by WBV. Real-time PCR assays show that WBV mitigated the reductions of tibial alkaline phosphatase (ALP), OCN, Runt-related transcription factor 2 (RUNX2), type I collagen (COL1), BMP2, Wnt3a, Lrp6, and β-catenin mRNA expression, and prevented the increases of tibial sclerostin (SOST), RANK, RANKL, RANL/osteoprotegerin (OPG) gene levels in db/db mice. Our results show that WBV promoted bone quantity and quality in db/db mice with obvious anabolic and anticatabolic effects. This study not only enriches our basic knowledge about bone quality and bone turnover mechanisms in leptin receptor-deficient animals, but also advances our understanding of the skeletal sensitivity of leptin-resistant db/db mice in response to external mechanical stimulation. © 2016 American Society for Bone and Mineral Research.
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Affiliation(s)
- Da Jing
- Institute of Orthopaedics, Xijing Hospital, Fourth Military Medical University, Xi'an, China.,Department of Biomedical Engineering, Fourth Military Medical University, Xi'an, China
| | - Erping Luo
- Department of Biomedical Engineering, Fourth Military Medical University, Xi'an, China
| | - Jing Cai
- Department of Endocrinology, Xijing Hospital, Fourth Military Medical University, Xi'an, China
| | - Shichao Tong
- Department of Biomedical Engineering, Fourth Military Medical University, Xi'an, China
| | - Mingming Zhai
- Department of Biomedical Engineering, Fourth Military Medical University, Xi'an, China
| | - Guanghao Shen
- Department of Biomedical Engineering, Fourth Military Medical University, Xi'an, China
| | - Xin Wang
- Department of Preventive Medicine, Fourth Military Medical University, Xi'an, China
| | - Zhuojing Luo
- Institute of Orthopaedics, Xijing Hospital, Fourth Military Medical University, Xi'an, China
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30
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Huang L, You YK, Zhu TY, Zheng LZ, Huang XR, Chen HY, Yao D, Lan HY, Qin L. Validity of leptin receptor-deficiency (db/db) type 2 diabetes mellitus mice as a model of secondary osteoporosis. Sci Rep 2016; 6:27745. [PMID: 27283954 PMCID: PMC4901274 DOI: 10.1038/srep27745] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2015] [Accepted: 05/23/2016] [Indexed: 01/22/2023] Open
Abstract
This study aimed to evaluate the validation of the leptin receptor-deficient mice model for secondary osteoporosis associated with type 2 diabetes mellitus (T2DM) at bone micro-architectural level. Thirty three 36-week old male mice were divided into four groups: normal control (db/m) (n = 7), leptin receptor-deficient T2DM (db/db) (n = 8), human C-reactive protein (CRP) transgenic normal control (crp/db/m) (n = 7), and human CRP transgenic T2DM (crp/db/db) (n = 11). Lumber vertebrae (L5) and bilateral lower limbs were scanned by micro-CT to analyze trabecular and cortical bone quality. Right femora were used for three-point bending to analyze the mechanical properties. Trabecular bone quality at L5 was better in db/db or crp/db/db group in terms of bone mineral density (BMD), bone volume fraction, connectivity density, trabecular number and separation (all p < 0.05). However the indices measured at proximal tibia showed comparable trabecular BMD and microarchitecture among the four groups. Femur length in crp/db/db group was significantly shorter than db/m group (p < 0.05) and cortices were thinner in db/db and crp/db/db groups (p > 0.05). Maximum loading and energy yield in mechanical test were similar among groups while the elastic modulus in db/db and crp/db/db significantly lower than db/m. The leptin-receptor mice is not a proper model for secondary osteoporosis associated with T2DM.
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Affiliation(s)
- Le Huang
- Musculoskeletal Research Laboratory, Department of Orthopaedics and Traumatology, the Chinese University of Hong Kong, Hong Kong SAR, China
| | - Yong-Ke You
- Department of Medicine &Therapeutics, the Chinese University of Hong Kong, Hong Kong SAR, China
| | - Tracy Y Zhu
- Bone Quality and Health Assessment Centre, Department of Orthopaedics and Traumatology, The Chinese University of Hong Kong, Hong Kong SAR, China
| | - Li-Zhen Zheng
- Musculoskeletal Research Laboratory, Department of Orthopaedics and Traumatology, the Chinese University of Hong Kong, Hong Kong SAR, China
| | - Xiao-Ru Huang
- Department of Medicine &Therapeutics, the Chinese University of Hong Kong, Hong Kong SAR, China
| | - Hai-Yong Chen
- Department of Medicine &Therapeutics, the Chinese University of Hong Kong, Hong Kong SAR, China
| | - Dong Yao
- Musculoskeletal Research Laboratory, Department of Orthopaedics and Traumatology, the Chinese University of Hong Kong, Hong Kong SAR, China
| | - Hui-Yao Lan
- Department of Medicine &Therapeutics, the Chinese University of Hong Kong, Hong Kong SAR, China
| | - Ling Qin
- Musculoskeletal Research Laboratory, Department of Orthopaedics and Traumatology, the Chinese University of Hong Kong, Hong Kong SAR, China.,Bone Quality and Health Assessment Centre, Department of Orthopaedics and Traumatology, The Chinese University of Hong Kong, Hong Kong SAR, China
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31
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Mansur SA, Mieczkowska A, Flatt PR, Bouvard B, Chappard D, Irwin N, Mabilleau G. A new stable GIP-Oxyntomodulin hybrid peptide improved bone strength both at the organ and tissue levels in genetically-inherited type 2 diabetes mellitus. Bone 2016; 87:102-13. [PMID: 27062994 DOI: 10.1016/j.bone.2016.04.001] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/06/2015] [Revised: 03/30/2016] [Accepted: 04/04/2016] [Indexed: 12/25/2022]
Abstract
Obesity and type 2 diabetes mellitus (T2DM) progress worldwide with detrimental effects on several physiological systems including bone tissue mainly by affecting bone quality. Several gut hormones analogues have been proven potent in ameliorating bone quality. In the present study, we used the leptin receptor-deficient db/db mice as a model of obesity and severe T2DM to assess the extent of bone quality alterations at the organ and tissue levels. We also examined the beneficial effects of gut hormone therapy in this model by using a new triple agonist ([d-Ala(2)]GIP-Oxm) active at the GIP, GLP-1 and glucagon receptors. As expected, db/db mice presented with dramatic alterations of bone strength at the organ level associated with deterioration of trabecular and cortical microarchitectures and an augmentation in osteoclast numbers. At the tissue level, these animals presented also with alterations of bone strength (reduced hardness, indentation modulus and dissipated energy) with modifications of tissue mineral distribution, collagen glycation and collagen maturity. The use of [d-Ala(2)]GIP-Oxm considerably improved bone strength at the organ level with modest effects on trabecular microarchitecture. At the tissue level, [d-Ala(2)]GIP-Oxm ameliorated bone strength reductions with positive effects on collagen glycation and collagen maturity. This study provides support for including gut hormone analogues as possible new therapeutic strategies for improving bone quality in bone complications associated to T2DM.
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Affiliation(s)
- Sity Aishah Mansur
- Universiti Tun Hussein Onn Malaysia, Johor, Malaysia; School of Biomedical Sciences, University of Ulster, Coleraine, Northern Ireland, United Kingdom
| | - Aleksandra Mieczkowska
- GEROM Groupe Etudes Remodelage Osseux et bioMatériaux - LHEA, IRIS-IBS Institut de Biologie en Santé, CHU d'Angers, LUNAM Université, 49933 ANGERS Cedex, France
| | - Peter R Flatt
- Universiti Tun Hussein Onn Malaysia, Johor, Malaysia
| | - Beatrice Bouvard
- GEROM Groupe Etudes Remodelage Osseux et bioMatériaux - LHEA, IRIS-IBS Institut de Biologie en Santé, CHU d'Angers, LUNAM Université, 49933 ANGERS Cedex, France
| | - Daniel Chappard
- GEROM Groupe Etudes Remodelage Osseux et bioMatériaux - LHEA, IRIS-IBS Institut de Biologie en Santé, CHU d'Angers, LUNAM Université, 49933 ANGERS Cedex, France; SCIAM, Service Commun d'Imagerie et Analyses Microscopiques, IRIS-IBS Institut de Biologie en Santé, CHU d'Angers, LUNAM Université, 49933 ANGERS Cedex, France
| | - Nigel Irwin
- Universiti Tun Hussein Onn Malaysia, Johor, Malaysia
| | - Guillaume Mabilleau
- GEROM Groupe Etudes Remodelage Osseux et bioMatériaux - LHEA, IRIS-IBS Institut de Biologie en Santé, CHU d'Angers, LUNAM Université, 49933 ANGERS Cedex, France; SCIAM, Service Commun d'Imagerie et Analyses Microscopiques, IRIS-IBS Institut de Biologie en Santé, CHU d'Angers, LUNAM Université, 49933 ANGERS Cedex, France.
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32
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Yarrow JF, Toklu HZ, Balaez A, Phillips EG, Otzel DM, Chen C, Wronski TJ, Aguirre JI, Sakarya Y, Tümer N, Scarpace PJ. Fructose consumption does not worsen bone deficits resulting from high-fat feeding in young male rats. Bone 2016; 85:99-106. [PMID: 26855373 PMCID: PMC4801515 DOI: 10.1016/j.bone.2016.02.004] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/15/2015] [Revised: 01/29/2016] [Accepted: 02/04/2016] [Indexed: 11/16/2022]
Abstract
Dietary-induced obesity (DIO) resulting from high-fat (HF) or high-sugar diets produces a host of deleterious metabolic consequences including adverse bone development. We compared the effects of feeding standard rodent chow (Control), a 30% moderately HF (starch-based/sugar-free) diet, or a combined 30%/40% HF/high-fructose (HF/F) diet for 12weeks on cancellous/cortical bone development in male Sprague-Dawley rats aged 8weeks. Both HF feeding regimens reduced the lean/fat mass ratio, elevated circulating leptin, and reduced serum total antioxidant capacity (tAOC) when compared with Controls. Distal femur cancellous bone mineral density (BMD) was 23-34% lower in both HF groups (p<0.001) and was characterized by lower cancellous bone volume (BV/TV, p<0.01), lower trabecular number (Tb.N, p<0.001), and increased trabecular separation versus Controls (p<0.001). Cancellous BMD, BV/TV, and Tb.N were negatively associated with leptin and positively associated with tAOC at the distal femur. Similar cancellous bone deficits were observed at the proximal tibia, along with increased bone marrow adipocyte density (p<0.05), which was negatively associated with BV/TV and Tb.N. HF/F animals also exhibited lower osteoblast surface and reduced circulating osteocalcin (p<0.05). Cortical thickness (p<0.01) and tissue mineral density (p<0.05) were higher in both HF-fed groups versus Controls, while whole bone biomechanical characteristics were not different among groups. These results demonstrate that "westernized" HF diets worsen cancellous, but not cortical, bone parameters in skeletally-immature male rats and that fructose incorporation into HF diets does not exacerbate bone loss. In addition, they suggest that leptin and/or oxidative stress may influence DIO-induced alterations in adolescent bone development.
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Affiliation(s)
- Joshua F Yarrow
- Research Service, Malcom Randall Department of Veterans Affairs Medical Center, North Florida/South Georgia Veterans Health System, Gainesville, FL 32608, USA; Department of Applied Physiology and Kinesiology, University of Florida, Gainesville, FL 32611, USA.
| | - Hale Z Toklu
- Geriatric Research, Education, and Clinical Center (GRECC), Malcom Randall Department of Veterans Affairs Medical Center, North Florida/South Georgia Veterans Health System, Gainesville, FL 32608, USA; Department of Pharmacology and Therapeutics, University of Florida, Gainesville, FL 32611, USA
| | - Alex Balaez
- Research Service, Malcom Randall Department of Veterans Affairs Medical Center, North Florida/South Georgia Veterans Health System, Gainesville, FL 32608, USA
| | - Ean G Phillips
- Research Service, Malcom Randall Department of Veterans Affairs Medical Center, North Florida/South Georgia Veterans Health System, Gainesville, FL 32608, USA
| | - Dana M Otzel
- Geriatric Research, Education, and Clinical Center (GRECC), Malcom Randall Department of Veterans Affairs Medical Center, North Florida/South Georgia Veterans Health System, Gainesville, FL 32608, USA
| | - Cong Chen
- Department of Orthopaedics and Rehabilitation, University of Florida, Gainesville, FL 32611, USA
| | - Thomas J Wronski
- Department of Physiological Sciences, University of Florida, Gainesville, FL 32611, USA
| | - J Ignacio Aguirre
- Department of Physiological Sciences, University of Florida, Gainesville, FL 32611, USA
| | - Yasemin Sakarya
- Geriatric Research, Education, and Clinical Center (GRECC), Malcom Randall Department of Veterans Affairs Medical Center, North Florida/South Georgia Veterans Health System, Gainesville, FL 32608, USA; Department of Pharmacology and Therapeutics, University of Florida, Gainesville, FL 32611, USA
| | - Nihal Tümer
- Geriatric Research, Education, and Clinical Center (GRECC), Malcom Randall Department of Veterans Affairs Medical Center, North Florida/South Georgia Veterans Health System, Gainesville, FL 32608, USA; Department of Pharmacology and Therapeutics, University of Florida, Gainesville, FL 32611, USA
| | - Philip J Scarpace
- Department of Pharmacology and Therapeutics, University of Florida, Gainesville, FL 32611, USA
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33
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Liu A, Li Y, Wang Y, Liu L, Shi H, Qiu Y. Exogenous Parathyroid Hormone-Related Peptide Promotes Fracture Healing in Lepr(-/-) Mice. Calcif Tissue Int 2015; 97:581-91. [PMID: 26314884 DOI: 10.1007/s00223-015-0041-2] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/23/2015] [Accepted: 07/15/2015] [Indexed: 10/23/2022]
Abstract
Diabetic osteoporosis continues to surge worldwide, increasing the risk of fracture. We have previously demonstrated that haploinsufficiency of endogenous parathyroid hormone-related peptide (PTHrP) impairs fracture healing. However, whether an exogenous supply of PTHrP can repair bone damage and accelerate fracture healing remains unclear. This study aimed to assess the efficacy and safety of PTHrP in healing fractures. Standardized mid-diaphyseal femur fractures were generated in 12-week-old wild-type and leptin receptor null Lepr(-/-) mice. After administration of PTHrP for 2 weeks, callus tissue properties were analyzed by radiography, micro-computed tomography, histology, histochemistry, immunohistochemistry, and molecular biology techniques. At 2 weeks post-fracture, cartilaginous callus areas were reduced, while total callus and bony callus areas were increased in PTHrP-treated Lepr(-/-) animals and control wild-type mice, compared with vehicle-treated Lepr(-/-) mice. The following parameters were enhanced both in Lepr(-/-) mice after treatment with PTHrP and vehicle-treated wild-type animals, compared with vehicle-treated Lepr(-/-) mice: osteoblast numbers; tissue alkaline phosphatase (ALP) and Type I collagen immunopositive areas; mRNA levels of ALP, Type I collagen, osteoprotegerin, and receptor activator for nuclear factor-κ B ligand; protein levels of Runt-related transcription factor 2 and insulin-like growth factor-1; and the number and surface of osteoclasts. In conclusion, exogenous PTHrP by subcutaneous injection promotes fracture repair in Lepr(-/-) mice by increasing callus formation and accelerating cell transformation: upregulated osteoblastic gene and protein expression, increased endochondral bone formation, osteoblastic bone formation, and osteoclastic bone resorption. However, complete repair was not obtained in PTHrP-treated Lepr(-/-) mice as in control wild-type animals.
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Affiliation(s)
- Anlong Liu
- Department of Orthopaedic Surgery, Nanjing Drum Tower Hospital, The Affiliated Hospital of Nanjing University Medical School, Nanjing, 210008, Jiangsu, China
| | - Yishan Li
- Department of International Training, PLA University of Science and Technology, Nanjing, 210007, Jiangsu, China
| | - Yinhe Wang
- Department of Orthopaedic Surgery, Nanjing Drum Tower Hospital, The Affiliated Hospital of Nanjing University Medical School, Nanjing, 210008, Jiangsu, China.
| | - Li Liu
- Department of Orthopaedic Surgery, Nanjing Drum Tower Hospital, The Affiliated Hospital of Nanjing University Medical School, Nanjing, 210008, Jiangsu, China
| | - Hongfei Shi
- Department of Orthopaedic Surgery, Nanjing Drum Tower Hospital, The Affiliated Hospital of Nanjing University Medical School, Nanjing, 210008, Jiangsu, China
| | - Yong Qiu
- Department of Orthopaedic Surgery, Nanjing Drum Tower Hospital, The Affiliated Hospital of Nanjing University Medical School, Nanjing, 210008, Jiangsu, China.
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34
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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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35
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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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Fajardo RJ, Karim L, Calley VI, Bouxsein ML. A review of rodent models of type 2 diabetic skeletal fragility. J Bone Miner Res 2014; 29:1025-40. [PMID: 24585709 PMCID: PMC5315418 DOI: 10.1002/jbmr.2210] [Citation(s) in RCA: 115] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/16/2013] [Revised: 02/21/2014] [Accepted: 02/25/2014] [Indexed: 12/21/2022]
Abstract
Evidence indicating that adult type 2 diabetes (T2D) is associated with increased fracture risk continues to mount. Unlike osteoporosis, diabetic fractures are associated with obesity and normal to high bone mineral density, two factors that are typically associated with reduced fracture risk. Animal models will likely play a critical role in efforts to identify the underlying mechanisms of skeletal fragility in T2D and to develop preventative treatments. In this review we critically examine the ability of current rodent models of T2D to mimic the skeletal characteristics of human T2D. We report that although there are numerous rodent models of T2D, few have undergone thorough assessments of bone metabolism and strength. Further, we find that many of the available rodent models of T2D have limitations for studies of skeletal fragility in T2D because the onset of diabetes is often prior to skeletal maturation and bone mass is low, in contrast to what is seen in adult humans. There is an urgent need to characterize the skeletal phenotype of existing models of T2D, and to develop new models that more closely mimic the skeletal effects seen in adult-onset T2D in humans.
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Affiliation(s)
- Roberto J. Fajardo
- Department of Orthopaedics, University of Texas Health Science Center at San Antonio
| | - Lamya Karim
- Center for Advanced Orthopaedic Studies, Beth Israel Deaconess Medical Center and Harvard Medical School
| | - Virginia I. Calley
- Department of Orthopaedics, University of Texas Health Science Center at San Antonio
| | - Mary L. Bouxsein
- Center for Advanced Orthopaedic Studies, Beth Israel Deaconess Medical Center and Harvard Medical School
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Rőszer T, Józsa T, Kiss-Tóth ED, De Clerck N, Balogh L. Leptin receptor deficient diabetic (db/db) mice are compromised in postnatal bone regeneration. Cell Tissue Res 2013; 356:195-206. [PMID: 24343796 DOI: 10.1007/s00441-013-1768-6] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2013] [Accepted: 11/04/2013] [Indexed: 12/24/2022]
Abstract
Increased fragility fracture risk with improper healing is a frequent and severe complication of insulin resistance (IR). The mechanisms impairing bone health in IR are still not fully appreciated, which gives importance to studies on bone pathologies in animal models of diabetes. Mice deficient in leptin signaling are widely used models of IR and its comorbidities. Leptin was first recognized as a hormone, regulating appetite and energy balance; however, recent studies have expanded its role showing that leptin is a link between insulin-dependent metabolism and bone homeostasis. In the light of these findings, it is intriguing to consider the role of leptin resistance in bone regeneration. In this study, we show that obese diabetic mice lacking leptin receptor (db/db) are deficient in postnatal regenerative osteogenesis. We apply an ectopic osteogenesis and a fracture healing model, both showing that db/db mice display compromised bone acquisition and regeneration capacity. The underlying mechanisms include delayed periosteal mesenchymatic osteogenesis, premature apoptosis of the cartilage callus and impaired microvascular invasion of the healing tissue. Our study supports the use of the db/db mouse as a model of IR associated bone-healing deficits and can aid further studies of mesenchymatic cell homing and differentiation, microvascular invasion, cartilage to bone transition and callus remodeling in diabetic fracture healing.
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Affiliation(s)
- Tamás Rőszer
- Department of Cardiovascular Development and Repair, Spanish National Cardiovascular Research Center (Centro Nacional de Investigaciones Cardiovasculares Carlos III), Calle Melchor Fernández Almagro 3, 28029, Madrid, Spain,
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Inzana JA, Kung M, Shu L, Hamada D, Xing LP, Zuscik MJ, Awad HA, Mooney RA. Immature mice are more susceptible to the detrimental effects of high fat diet on cancellous bone in the distal femur. Bone 2013; 57:174-83. [PMID: 23954757 PMCID: PMC3826882 DOI: 10.1016/j.bone.2013.08.003] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/22/2013] [Revised: 08/01/2013] [Accepted: 08/08/2013] [Indexed: 11/28/2022]
Abstract
With the increasing prevalence of obesity among children and adolescents, it is imperative to understand the implications of early diet-induced obesity on bone health. We hypothesized that cancellous bone of skeletally immature mice is more susceptible to the detrimental effects of a high fat diet (HFD) than mature mice, and that removing excess dietary fat will reverse these adverse effects. Skeletally immature (5weeks old) and mature (20weeks old) male C57BL/6J mice were fed either a HFD (60% kcal fat) or low fat diet (LFD; 10% kcal fat) for 12weeks, at which point, the trabecular bone structure in the distal femoral metaphysis and third lumbar vertebrae were evaluated by micro-computed tomography. The compressive strength of the vertebrae was also measured. In general, the HFD led to deteriorations in cancellous bone structure and compressive biomechanical properties in both age groups. The HFD-fed immature mice had a greater decrease in trabecular bone volume fraction (BVF) in the femoral metaphysis, compared to mature mice (p=0.017 by 2-way ANOVA). In the vertebrae, however, the HFD led to similar reductions in BVF and compressive strength in the two age groups. When mice on the HFD were switched to a LFD (HFD:LFD) for an additional 12weeks, the femoral metaphyseal BVF in immature mice showed no improvements, whereas the mature mice recovered their femoral metaphyseal BVF to that of age-matched lean controls. The vertebral BVF and compressive strength of HFD:LFD mouse bones, following diet correction, were equivalent to those of LFD:LFD mice in both age groups. These data suggest that femoral cancellous metaphyseal bone is more susceptible to the detrimental effects of HFD before skeletal maturity and is less able to recover after correcting the diet. Negative effects of HFD on vertebrae are less severe and can renormalize with LFD:LFD mice after diet correction, in both skeletally immature and mature animals.
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Affiliation(s)
- Jason A. Inzana
- Center for Musculoskeletal Research, University of Rochester Medical Center, 601 Elmwood Avenue, Box 665, Rochester, NY 14642, United States
- Department of Biomedical Engineering, University of Rochester, 207 Robert B. Goergen Hall, Rochester, NY 14642, United States
| | - Ming Kung
- Center for Musculoskeletal Research, University of Rochester Medical Center, 601 Elmwood Avenue, Box 665, Rochester, NY 14642, United States
| | - Lei Shu
- Department of Pathology and Laboratory Medicine, University of Rochester Medical Center, 601 Elmwood Avenue, Box 626, Rochester, NY 14642, United States
| | - Daisuke Hamada
- Center for Musculoskeletal Research, University of Rochester Medical Center, 601 Elmwood Avenue, Box 665, Rochester, NY 14642, United States
- Department of Pathology and Laboratory Medicine, University of Rochester Medical Center, 601 Elmwood Avenue, Box 626, Rochester, NY 14642, United States
| | - Lian Ping Xing
- Center for Musculoskeletal Research, University of Rochester Medical Center, 601 Elmwood Avenue, Box 665, Rochester, NY 14642, United States
- Department of Pathology and Laboratory Medicine, University of Rochester Medical Center, 601 Elmwood Avenue, Box 626, Rochester, NY 14642, United States
| | - Michael J. Zuscik
- Center for Musculoskeletal Research, University of Rochester Medical Center, 601 Elmwood Avenue, Box 665, Rochester, NY 14642, United States
| | - Hani A. Awad
- Center for Musculoskeletal Research, University of Rochester Medical Center, 601 Elmwood Avenue, Box 665, Rochester, NY 14642, United States
- Department of Biomedical Engineering, University of Rochester, 207 Robert B. Goergen Hall, Rochester, NY 14642, United States
| | - Robert A. Mooney
- Center for Musculoskeletal Research, University of Rochester Medical Center, 601 Elmwood Avenue, Box 665, Rochester, NY 14642, United States
- Department of Pathology and Laboratory Medicine, University of Rochester Medical Center, 601 Elmwood Avenue, Box 626, Rochester, NY 14642, United States
- Corresponding Author Robert A. Mooney, Ph.D., Department of Pathology and Laboratory Medicine, University of Rochester Medical Center, 601 Elmwood Avenue, Box 608, Rochester, NY 14642, United States, 1-585-275-7811,
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Abstract
BACKGROUND Obesity is a risk factor for various orthopaedic diseases, including fractures. Obesity's influence on circulating hormones and cytokines and bone mineralization ultimately influences the body's osteogenic response and bone mineralization, potentially increasing the risk of fracture and impacting fracture healing. QUESTIONS/PURPOSES Does obesity delay fracture recovery in overweight or obese children as measured by the time to release to normal activity? Is this average time for return to activity influenced by the mechanism of the injury? Does obesity's effect on mineralization and loading in overweight or obese children lead to a greater proportion of upper extremity fracture versus lower extremity fracture? METHODS We prospectively followed 273 patients with nonpathologic long bone fractures treated from January 2010 to October 2011. Patients were stratified into obese/overweight, normal weight, and underweight groups. All patients were followed until release to regular activities (mean, 41 days; range, 13-100 days). RESULTS Release to regular activities occurred sooner in obese/overweight than in normal weight patients: 39 and 42 days, respectively. A greater proportion of obese/overweight patients had low to moderate energy mechanisms of injury than did normal weight patients, but we found no difference between the groups in terms of return to activity when stratified by mechanism. There was also no difference in the proportion of upper extremity injuries between the two groups. CONCLUSIONS Obese/overweight children did not have a delay in release to activities compared with children of normal weight. LEVEL OF EVIDENCE Level II, prognostic study. See Guidelines for Authors for a complete description of levels of evidence.
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Affiliation(s)
- Rushyuan J. Lee
- Department of Orthopaedic Surgery, The Johns Hopkins University, Baltimore, MD USA
| | - Nigel N. Hsu
- Department of Orthopaedic Surgery, The Johns Hopkins University, Baltimore, MD USA
| | - Colleen M. Lenz
- Department of Orthopaedic Surgery, The Johns Hopkins University, Baltimore, MD USA
| | - Arabella I. Leet
- Shriners Hospital for Children®-Honolulu, 1310 Punahou Street, Honolulu, HI 96826-1099 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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Wang L, Tang X, Zhang H, Yuan J, Ding H, Wei Y. Elevated leptin expression in rat model of traumatic spinal cord injury and femoral fracture. J Spinal Cord Med 2011; 34:501-9. [PMID: 22118258 PMCID: PMC3184488 DOI: 10.1179/2045772311y.0000000034] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/31/2022] Open
Abstract
BACKGROUND Few studies have reported a relationship between leptin induced by spinal cord injury (SCI) and healing bone tissue. OBJECTIVE To observe serum and callus leptin expression within the setting of fracture and traumatic SCI. METHODS Seventy-two male Sprague Dawley rats were randomized equally into four groups: control, SCI group, fracture group, and fracture/SCI group. Rats were sacrificed at 7, 14, 21, and 28 days post-fracture/SCI. Serum leptin was detected using radioimmunoassay at 1, 7, 14, 21, and 28 days, and callus formation was measured radiologically at 14, 21, and 28 days. Callus leptin was analyzed by means of immunohistochemistry. RESULTS Serum leptin in the fracture group, SCI group, and combined fracture/SCI group were all significantly increased compared to control group at the 1, 7, 14, and 2-day time points (P < 0.05). Serum leptin in the combined fracture/SCI group was significantly higher than in the fracture group at 7, 14, and 21 days (P < 0.05), and higher than in SCI groups at 14 and 21days after operation (P < 0.05). The percentage of leptin-positive cells in the fracture/SCI callus, and callus volume was significantly higher than in the fracture-only group (P < 0.001). CONCLUSIONS Overall, elevated leptin expression was demonstrated within healing bone especially in the 21 days of a rat model combining fracture and SCI. A close association exists between leptin levels and the degree of callus formation in fractures.
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Affiliation(s)
- Lei Wang
- Department of Orthopedics, The Affiliated People's Hospital with Jiangsu University, Zhenjiang, Jiangsu Province, China
| | - Xingguo Tang
- Department of Orthopedics, The Affiliated People's Hospital with Jiangsu University, Zhenjiang, Jiangsu Province, China
| | - Hongxi Zhang
- Department of Orthopedics, The Affiliated People's Hospital with Jiangsu University, Zhenjiang, Jiangsu Province, China,Correspondence to: Hongxi Zhang, Dianli Road 8, Zhenjiang 212001, Jiangsu Province, China.
| | - Jishan Yuan
- Department of Orthopedics, The Affiliated People's Hospital with Jiangsu University, Zhenjiang, Jiangsu Province, China
| | - Hua Ding
- Department of Orthopedics, The Affiliated People's Hospital with Jiangsu University, Zhenjiang, Jiangsu Province, China
| | - Yongzhong Wei
- Department of Orthopedics, The First Affiliated Hospital with Nanjing University, Jiangsu Province, China
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Williams GA, Callon KE, Watson M, Costa JL, Ding Y, Dickinson M, Wang Y, Naot D, Reid IR, Cornish J. Skeletal phenotype of the leptin receptor-deficient db/db mouse. J Bone Miner Res 2011; 26:1698-709. [PMID: 21328476 DOI: 10.1002/jbmr.367] [Citation(s) in RCA: 91] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Leptin, a major hormonal product of the adipocyte, regulates appetite and reproductive function through its hypothalamic receptors. The leptin receptor is present in osteoblasts and chondrocytes, and previously we have shown leptin to be an anabolic bone factor in vitro, stimulating osteoblast proliferation and inhibiting osteoclastogenesis. Leptin increases bone mass and reduces bone fragility when administered peripherally but also can indirectly reduce bone mass when administered into the central nervous system. However, data from animal models deficient in either leptin (ob/ob) or its receptor (db/db) remain contradictory. We compared the bone phenotype of leptin receptor-deficient (db/db) and wild-type mice using micro-computed tomographic (µCT) analysis of the proximal tibias and vertebrae. In the tibia, db/db mice had reduced percent trabecular bone volume (13.0 ± 1.62% in wild-type versus 6.01 ± 0.601% in db/db mice, p = .002) and cortical bone volume (411 ± 21.5 µm(3) versus 316 ± 3.53 µm(3), p = .0014), trabecular thickness (48.4 ± 001.07 µm versus 45.1 ± 0.929 µm, p = .041) and trabecular number (2.68 ± 0.319 mm(-1) versus 1.34 ± 0.148 mm(-1), p = .0034). In the fifth lumbar vertebral body, the trabecular thickness and cortical thickness were decreased in the db/db versus wild-type mice (0.053 ± 0.0011 mm versus 0.047 ± 0.0013 mm, p = .0002 and 0.062 ± 0.00054 mm versus 0.056 ± 0.0009 mm, p = .0001), respectively, whereas the trabecular and cortical percent bone volume and trabecular number did not reach significance. The total (endosteal and periosteal) cortical perimeter (12.2 ± 0.19 mm versus 13.2 ± 0.30 mm, p = .01) was increased. The serum osteocalcin levels were reduced in the db/db mice, suggesting that bone formation rates are decreased. The material properties of db/db femurs were determined by three-point bending and nanoindentation, showing decreased bone strength (13.3 ± 0.280 N versus 7.99 ± 0.984 N, p = .0074) and material stiffness (28.5 ± 0.280 GPa versus 25.8 ± 0.281 GPa, p < .0001). These results demonstrate that bone mass and strength are reduced in the absence of leptin signaling, indicating that leptin acts in vivo as an anabolic bone factor. This concurs with results of in vitro studies and of peripheral leptin administration in vivo and suggests that leptin's direct effects on bone cells are likely to override its actions via the central nervous system.
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Affiliation(s)
- Garry A Williams
- Department of Medicine, University of Auckland, Auckland, New Zealand.
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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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Scheller EL, Leinninger GM, Hankenson KD, Myers MG, Krebsbach PH. Ectopic expression of Col2.3 and Col3.6 promoters in the brain and association with leptin signaling. Cells Tissues Organs 2011; 194:268-73. [PMID: 21555864 DOI: 10.1159/000324745] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
The collagen 2.3 and 3.6 promoters have been used to drive Cre expression for generation of conditional transgenic mutant mice. Within the bone, Col3.6 is expressed by mesenchymal precursor cells and their downstream progeny, while Col2.3 is more osteoblast specific. Our generation of transgenic mice with Col2.3-Cre- and Col3.6-Cre-driven deletion of the long-form leptin receptor (ObRb) necessitated a thorough analysis of the nonspecific expression of these promoters in the central nervous system. Both Col2.3 and Col3.6 were capable of forcing loxP recombination in the brain as demonstrated by EGFP expression in ROSA reporter mice. Expression of Col2.3 was limited to the central base of the brain near the third ventricle. In contrast, robust expression of Col3.6 was noted throughout the brain, centering near the distal third ventricle, third ventricle, and aqueduct. We subsequently analyzed the colocalization of leptin-responsive P-Stat3 neurons with Col3.6-expressing neurons. Approximately 5-10% colocalization was noted in leptin-responsive brain areas such as the arcuate nucleus, dorsal medial hypothalamus, ventral premammillary nucleus, and lateral hypothalamus. Injection of 3.6(Cre+F/F) ObRb knockout mice with leptin confirmed the presence of an intact P-Stat3 response that was dampened in the lateral hypothalamus (p < 0.050). This test was done to explore the contribution of neural leptin signaling to the bone phenotype of the 3.6(Cre+F/F) mice. Our analysis indicates that neural ObRb deletion, while present, is likely not the sole driver of femoral changes through traditional sympathetic circuits.
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Affiliation(s)
- Erica L Scheller
- University of Michigan School of Dentistry, Ann Arbor, Mich., USA
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Li XF, Yan J, Jiang LS, Dai LY. Age-related variations of leptin receptor expression in the growth plate of spine and limb: gender- and region-specific changes. Histochem Cell Biol 2011; 135:487-97. [PMID: 21452040 DOI: 10.1007/s00418-011-0805-3] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/15/2011] [Indexed: 01/17/2023]
Abstract
Leptin is a potent growth-stimulating factor of bone. The effects of leptin on bone growth differ significantly between axial and appendicular regions. Gender differences of leptin function have also been suggested in normal pubertal development. To explore the mechanisms underlying these effects, we investigated the spatial and temporal expressions of the active form of the leptin receptor (Ob-Rb) in the tibial and spinal growth plates of the female and male rats during postnatal development. The 1-, 4-, 7-, 12- and 16-week age stages are representative for early life, puberty and early adulthood after puberty, respectively. Quantitative real-time PCR was used for Ob-Rb mRNA examination and comparison. The spatial location of Ob-Rb was determined by immunohistochemical analysis. There were gender- and region-specific differences in Ob-Rb mRNA expression in the growth plate. Mainly cytoplasm staining of Ob-Rb immunoreactivity was observed in the spinal and tibial growth plate chondrocytes of both genders. Spatial differences of region- and gender-related Ob-Rb expression were not observed. Ob-Rb immunoreactivity was detected in the resting, proliferative and prehypertrophic chondrocytes in early life stage and during puberty. After puberty, staining was mainly located in the late proliferative and hypertrophic chondrocytes. The results of Ob-Rb HSCORE analysis were similar to those obtained from quantitative real-time PCR. Our study indicated direct effects on the chondrocytes of the growth plate in different development stages. The region-specific expression patterns of Ob-Rb gene might be one possible reason for contrasting phenotypes in limb and spine. Different Ob-Rb expression patterns might partly contribute to age- and gender- related differences in trabecular bone mass.
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Affiliation(s)
- Xin-Feng Li
- Department of Orthopedic Surgery, Xinhua Hospital, Shanghai Jiaotong University School of Medicine, 1665 Kongjiang Road, 200092, Shanghai, China
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Wei Y, Wang L, Clark JCM, Dass CR, Choong PFM. Elevated leptin expression in a rat model of fracture and traumatic brain injury. J Pharm Pharmacol 2010. [DOI: 10.1211/jpp.60.12.0013] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Abstract
A few studies have reported a relationship between leptin induced by brain injury and healing of bone tissue. Our objective was to measure serum and callus leptin expression within the setting of fracture and traumatic brain injury (TBI). Sixty-four male Sprague-Dawley rats were randomised equally into four groups: control, TBI group, fracture group and fracture/TBI group. Rats were sacrificed at 2, 4, 8 and 12 weeks after fracture/TBI. Serum leptin was detected using radio-immunoassay, and callus formation was measured radiologically. Callus leptin was analysed with immunohistochemistry. Serum leptin was significantly increased in the fracture, TBI and combined fracture/TBI groups compared with the control group at 2 weeks (P < 0.05). Serum leptin was significantly higher in the combined fracture/TBI group than in the fracture and TBI groups at 4 and 8 weeks (P < 0.05). The percentage of leptin-positive cells in the callus and callus volume were significantly higher in the fracture/TBI group than in the fracture-only group (P < 0.001). Thus, we demonstrated elevated leptin expression within healing bone, particularly in the first 8 weeks of a rat model combining fracture and TBI. A close association exists between leptin levels and the degree of callus formation in fractures.
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Affiliation(s)
- Yongzhong Wei
- Department of Orthopedics, The First Affiliated Hospital with Nanjing Medical University, China
| | - Lei Wang
- Department of Orthopedics, The First Affiliated Hospital with Nanjing Medical University, China
| | - Jonathan C M Clark
- Department of Orthopedics, St Vincent's Hospital Melbourne and Melbourne University, Australia
| | - Crispin R Dass
- Department of Orthopedics, St Vincent's Hospital Melbourne and Melbourne University, Australia
| | - Peter F M Choong
- Department of Orthopedics, St Vincent's Hospital Melbourne and Melbourne University, Australia
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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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Abstract
Emerging evidence points to a critical role for the skeleton in several homeostatic processes, including energy balance. The connection between fuel utilization and skeletal remodeling begins in the bone marrow with lineage allocation of mesenchymal stem cells to adipocytes or osteoblasts. Mature bone cells secrete factors that influence insulin sensitivity, and fat cells synthesize cytokines that regulate osteoblast differentiation; thus, these two pathways are closely linked. The emerging importance of the bone-fat interaction suggests that novel molecules could be used as targets to enhance bone formation and possibly prevent fractures. In this article, we discuss three pathways that could be pharmacologically targeted for the ultimate goal of enhancing bone mass and reducing osteoporotic fracture risk: the leptin, peroxisome proliferator-activated receptor gamma and osteocalcin pathways. Not surprisingly, because of the complex interactions across homeostatic networks, other pathways will probably be activated by this targeting, which could prove to be beneficial or detrimental for the organism. Hence, a more complete picture of energy utilization and skeletal remodeling will be required to bring any potential agents into the future clinical armamentarium.
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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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Støving RK, Andries A, Brixen K, Flyvbjerg A, Hørder K, Frystyk J. Leptin, ghrelin, and endocannabinoids: potential therapeutic targets in anorexia nervosa. J Psychiatr Res 2009; 43:671-9. [PMID: 18926548 DOI: 10.1016/j.jpsychires.2008.09.007] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/15/2008] [Revised: 08/30/2008] [Accepted: 09/12/2008] [Indexed: 11/18/2022]
Abstract
Anorexia nervosa (AN) has the highest mortality rate between psychiatric disorders, and evidence for managing it is still very limited. So far, pharmacological treatment has focused on a narrow range of drugs and only a few controlled studies have been performed. Furthermore, the studies have been of short duration and included a limited number of subjects, often heterogenic with regard to stage and acute nutritive status. Thus, novel approaches are urgently needed. Body weight homeostasis is tightly regulated throughout life. With the discovery of orexigenic and anorectic signals, an array of new molecular targets to control eating behavior has emerged. This review focuses on recent advances in three important signal systems: leptin, ghrelin, and endocannabinoids toward the identification of potential therapeutical breakthroughs in AN. Our review of the current literature shows that leptin may have therapeutic potentials in promoting restoration of menstrual cycles in weight restored patients, reducing motor restlessness in severely hyperactive patients, and preventing osteoporosis in chronic patients. Ghrelin and endocannabinoids exert orexigenic effects which may facilitate nutritional restoration. Leptin and endocannabinoids may exert antidepressive and anxiolytic effects. Finally, monitoring serum concentration of leptin may be useful in order to prevent refeeding syndrome.
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Affiliation(s)
- René Klinkby Støving
- Center for Eating Disorders and Department of Endocrinology, Odense University Hospital, DK-5000 Odense, Denmark.
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