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Wang Z, Zhao Z, Gao B, Zhang L. Exosome mediated biological functions within skeletal microenvironment. Front Bioeng Biotechnol 2022; 10:953916. [PMID: 35935491 PMCID: PMC9355125 DOI: 10.3389/fbioe.2022.953916] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2022] [Accepted: 06/29/2022] [Indexed: 12/02/2022] Open
Abstract
Exosomes are membranous lipid vesicles fused with intracellular multicellular bodies that are released into the extracellular environment. They contain bioactive substances, including proteins, RNAs, lipids, and cytokine receptors. Exosomes in the skeletal microenvironment are derived from a variety of cells such as bone marrow mesenchymal stem cells (BMSCs), osteoblasts, osteoclasts, and osteocytes. Their biological function is key in paracrine or endocrine signaling. Exosomes play a role in bone remodeling by regulating cell proliferation and differentiation. Genetic engineering technology combined with exosome-based drug delivery can therapy bone metabolic diseases. In this review, we summarized the pathways of exosomes derived from different skeletal cells (i.e., BMSCs, osteoblasts, osteocytes, and osteoclasts) regulate the skeletal microenvironment through proteins, mRNAs, and non-coding RNAs. By exploring the role of exosomes in the skeletal microenvironment, we provide a theoretical basis for the clinical treatment of bone-related metabolic diseases, which may lay the foundation to improve bone tumor microenvironments, alleviate drug resistance in patients.
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Affiliation(s)
- Zhikun Wang
- School of Kinesiology, Shanghai University of Sport, Shanghai, China
| | - Zhonghan Zhao
- School of Kinesiology, Shanghai University of Sport, Shanghai, China
| | - Bo Gao
- Institute of Orthopedic Surgery, Xijing Hospital, Fourth Military Medical University, Xi’an, China
- *Correspondence: Bo Gao, ; Lingli Zhang,
| | - Lingli Zhang
- College of Athletic Performance, Shanghai University of Sport, Shanghai, China
- *Correspondence: Bo Gao, ; Lingli Zhang,
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2
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Yan X, Kononenko NL, Brüel A, Thomsen JS, Poy MN. Neuronal Cell Adhesion Molecule 1 Regulates Leptin Sensitivity and Bone Mass. Calcif Tissue Int 2018; 102:329-336. [PMID: 29134237 DOI: 10.1007/s00223-017-0361-5] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/17/2017] [Accepted: 11/04/2017] [Indexed: 12/24/2022]
Abstract
The central nervous system is widely known to exert control over our systemic physiology via several mechanisms including the regulation of skeletal metabolism. Neuronal circuits within the hypothalamus have been shown to impact bone mass via leptin-dependent and independent mechanisms; however, the full extent to which the brain controls bone homeostasis is not known. We previously identified cell adhesion molecule1 (Cadm1) as a regulator of body weight and energy homeostasis via its expression in multiple regions of the brain. Here, we show that loss of Cadm1 expression in excitatory neurons results in increased leptin sensitivity in addition to a concomitant reduction in bone mass. Femoral length, bone mineral content, diaphyseal cross-sectional area, and bone strength were all lower in Cadm1-deficient animals. Conversely, inducing expression of Cadm1 in excitatory neurons decreased leptin sensitivity and increased femoral length, bone mineral content, and diaphyseal cross-sectional area. Together, these results illustrate an essential role for this synaptic protein in the neuronal regulation of skeletal bone metabolism.
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Affiliation(s)
- Xin Yan
- Max Delbrück Center for Molecular Medicine, Robert Rössle Strasse 10, 13125, Berlin, Germany
| | - Natalia L Kononenko
- CECAD Research Center, University of Cologne, Joseph-Stelzmann-Str. 26, 50931, Cologne, Germany
| | - Annemarie Brüel
- Institute of Biomedicine, Aarhus University, Wilhelm Meyers Allé 3, 8000, Aarhus C, Denmark
| | - Jesper Skovhus Thomsen
- Institute of Biomedicine, Aarhus University, Wilhelm Meyers Allé 3, 8000, Aarhus C, Denmark
| | - Matthew N Poy
- Max Delbrück Center for Molecular Medicine, Robert Rössle Strasse 10, 13125, Berlin, Germany.
- Max Delbrück Center for Molecular Medicine, Robert Rössle Strasse 10, WFH C27, Rm 131, 13125, Berlin, Germany.
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3
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Wei J, Flaherty S, Karsenty G. Searching for additional endocrine functions of the skeleton: genetic approaches and implications for therapeutics. Expert Rev Endocrinol Metab 2015; 10:413-424. [PMID: 27588033 PMCID: PMC5004930 DOI: 10.1586/17446651.2015.1058152] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
Our knowledge of whole organism physiology has greatly advanced in the past decades through mouse genetics. In particular, genetic studies have revealed that most organs interact with one another through hormones in order to maintain normal physiological functions and the homeostasis of the entire organism. Remarkably, through these studies many unexpected novel endocrine means to regulate physiological functions have been uncovered. The skeletal system is one example. In this article, we review a series of studies that over the years have identified bone as an endocrine organ. The mechanism of action, pathological relevance, and therapeutic implications of the functions of the bone-derived hormone osteocalcin are discussed. In the last part of this review we discuss the possibility that additional endocrine functions of the skeleton may exist.
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Affiliation(s)
- Jianwen Wei
- Department of Genetics & Development, College of Physicians and Surgeons, Columbia University, New York, NY 10032, USA
| | - Stephen Flaherty
- Department of Genetics & Development, College of Physicians and Surgeons, Columbia University, New York, NY 10032, USA
| | - Gerard Karsenty
- Department of Genetics & Development, College of Physicians and Surgeons, Columbia University, New York, NY 10032, USA
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Londraville RL, Macotela Y, Duff RJ, Easterling MR, Liu Q, Crespi EJ. Comparative endocrinology of leptin: assessing function in a phylogenetic context. Gen Comp Endocrinol 2014; 203:146-57. [PMID: 24525452 PMCID: PMC4128956 DOI: 10.1016/j.ygcen.2014.02.002] [Citation(s) in RCA: 77] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/30/2013] [Revised: 01/31/2014] [Accepted: 02/03/2014] [Indexed: 12/11/2022]
Abstract
As we approach the end of two decades of leptin research, the comparative biology of leptin is just beginning. We now have several leptin orthologs described from nearly every major clade among vertebrates, and are moving beyond gene descriptions to functional studies. Even at this early stage, it is clear that non-mammals display clear functional similarities and differences with their better-studied mammalian counterparts. This review assesses what we know about leptin function in mammals and non-mammals, and gives examples of how these data can inform leptin biology in humans.
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Affiliation(s)
- Richard L Londraville
- Department of Biology and Program in Integrated Biosciences, University of Akron, Akron, OH, USA.
| | - Yazmin Macotela
- Instituto de Neurobiología, Universidad Nacional Autónoma de México, Querétaro, Mexico
| | - Robert J Duff
- Department of Biology and Program in Integrated Biosciences, University of Akron, Akron, OH, USA
| | - Marietta R Easterling
- School of Biological Sciences and Center for Reproductive Biology, Washington State University, Pullman, WA 99164, USA
| | - Qin Liu
- Department of Biology and Program in Integrated Biosciences, University of Akron, Akron, OH, USA
| | - Erica J Crespi
- School of Biological Sciences and Center for Reproductive Biology, Washington State University, Pullman, WA 99164, USA
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Viljakainen H, Ivaska KK, Paldánius P, Lipsanen-Nyman M, Saukkonen T, Pietiläinen KH, Andersson S, Laitinen K, Mäkitie O. Suppressed bone turnover in obesity: a link to energy metabolism? A case-control study. J Clin Endocrinol Metab 2014; 99:2155-63. [PMID: 24606073 DOI: 10.1210/jc.2013-3097] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
CONTEXT Observations in rodents suggest that osteocalcin (OC) participates in glucose metabolism. Based on human studies, it remains unclear whether circulating OC is simply a bone turnover marker (BTM) or also a mediator in interactions between the skeleton and glucose homeostasis. OBJECTIVE The objective of the study was to determine the responses of BTMs, including OC, to oral glucose tolerance test (OGTT) in a case-control setting. DESIGN AND PATIENTS Thirty-four normoglycemic young adults [mean age 19 y (SD 2.3)] with severe childhood-onset obesity and their gender- and age-matched nonobese controls underwent a standard 2-hour OGTT. MAIN OUTCOME MEASURES Glucose, insulin, and six BTMs including total and carboxylated OC (cOC) were determined at baseline and at 30, 60, 90, and 120 minutes during OGTT. RESULTS The obese and control subjects were similar in height; the mean body mass indices were 40.4 and 21.9 kg/m(2), respectively. The homeostasis model assessment index was 2.7 times greater in the obese subjects. All BTMs, except bone-specific alkaline phophatase, were lower in the obese subjects compared with the controls: the differences at baseline were 40%, 35%, 17%, 31%, and 32% for N-terminal propeptides of type I collagen, cross-linked telopeptides of type I collagen, tartrate-resistant acid phosphatase, total OC, and carboxylated OC (P < .05 for all) after adjusting for whole-body bone area. All BTMs decreased during OGTT. The relative values for the OGTT responses for total, but not for cOC (measured as area under the curve) differed between the two groups (P = .029 and P = .139, respectively): the decrease in total OC during the OGTT was less pronounced in the obese subjects. Responses in other BTMs were similar between the groups. No associations were observed between glucose metabolism and OCs during OGTT with linear regression. CONCLUSIONS Bone turnover markers were substantially lower in obese subjects compared with controls. Total OC and cOC showed less pronounced decrease during the OGTT in obese subjects compared with controls, whereas other BTMs responded similarly in the two groups. The role of OC, if anything, in glucose homeostasis is indirect and may be mediated via other factors than glucose or insulin.
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Affiliation(s)
- Heli Viljakainen
- Children's Hospital (H.V., P.P., M.L.-N., T.S., S.A., O.M.), Helsinki University Central Hospital, Obesity Research Unit (K.H.P.), Research Programs Unit, Diabetes and Obesity, University of Helsinki, and Department of Medicine, Division of Endocrinology, Helsinki University Central Hospital and Institute for Molecular Medicine Finland, University of Helsinki, and Department of Obstetrics and Gynecology (K.L.), Helsinki University Central Hospital, FI-00029 Helsinki, Finland; Institute of Biomedicine (K.K.I.), Department of Cell Biology and Anatomy, University of Turku, FI-20520 Turku, Finland; Novartis Pharma (P.P.), CH-4002 Basel, Switzerland; Novo Nordisk Farma Oy (T.S.), FI-02240 Espoo, Finland; Folkhälsan Research Center (O.M.), FI-00250 Helsinki, Finland; and Department of Molecular Medicine and Surgery (O.M.), Karolinska Institutet, SE-171 77 Stockholm, Sweden
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6
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Foo JP, Aronis KN, Chamberland JP, Thakkar B, Hamnvik OP, Brinkoetter M, Zaichenko L, Mantzoros CS. Gender dimorphism and lack of day/night variation or effects of energy deprivation on undercarboxylated osteocalcin levels in humans. Obesity (Silver Spring) 2013; 21:E527-32. [PMID: 23512912 PMCID: PMC4399799 DOI: 10.1002/oby.20453] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/24/2012] [Accepted: 02/28/2013] [Indexed: 11/12/2022]
Abstract
OBJECTIVE Undercarboxylated osteocalcin (ucOC) is a bone marker with potent metabolic effects. Leptin regulates Esp gene expression and osteocalcin carboxylation in animal models. We aim to elucidate day/night patterns of ucOC levels, whether short-term and/or chronic energy deprivation alters ucOC levels, and whether leptin may mediate these changes in humans. DESIGN AND METHODS Twelve healthy males and females were studied for 72 h in the fed state to study day/night pattern of ucOC. The six female subjects were also studied in a crossover interventional study in the fasting state for 72 h with administration of either placebo or metreleptin in physiological doses. Blood samples were obtained hourly from 0800 a.m. on day 3 until 0800 a.m. on day 4. In a separate study, eleven obese subjects who underwent bariatric surgery were followed for 24 weeks to examine the effects of postsurgery weight loss on ucOC levels. RESULTS Males have higher ucOC levels compared to females. There is no day/night variation pattern of circulating ucOC in humans. Short-term and chronic energy deprivation or leptin administrations do not alter ucOC levels. CONCLUSIONS The hypothesis that ucOC plays a role in energy homeostasis or of leptin in regulating ucOC in humans is not supported.
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Affiliation(s)
- Joo-Pin Foo
- Division of Endocrinology, Diabetes and Metabolism, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA
| | - Konstantinos N. Aronis
- Division of Endocrinology, Diabetes and Metabolism, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA
- Section of Endocrinology, Boston VA Healthcare System, Harvard Medical School, Boston, MA
| | - John P. Chamberland
- Division of Endocrinology, Diabetes and Metabolism, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA
- Section of Endocrinology, Boston VA Healthcare System, Harvard Medical School, Boston, MA
| | - Bindiya Thakkar
- Division of Endocrinology, Diabetes and Metabolism, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA
- Section of Endocrinology, Boston VA Healthcare System, Harvard Medical School, Boston, MA
| | - Ole-Petter Hamnvik
- Section of Endocrinology, Boston VA Healthcare System, Harvard Medical School, Boston, MA
- Division of Endocrinology, Diabetes and Hypertension, Brigham and Women’s Hospital, Harvard Medical School, Boston, MA
| | - Mary Brinkoetter
- Division of Endocrinology, Diabetes and Metabolism, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA
| | - Lesya Zaichenko
- Division of Endocrinology, Diabetes and Metabolism, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA
| | - Christos S. Mantzoros
- Division of Endocrinology, Diabetes and Metabolism, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA
- Section of Endocrinology, Boston VA Healthcare System, Harvard Medical School, Boston, MA
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7
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Bendik NF, Gluesenkamp AG. Body length shrinkage in an endangered amphibian is associated with drought. J Zool (1987) 2012. [DOI: 10.1111/jzo.12009] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Affiliation(s)
- N. F. Bendik
- Watershed Protection Department; City of Austin; Austin TX USA
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8
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Yassuda DH, Costa NFM, Fernandes GO, Alves GG, Granjeiro JM, Soares GDA. Magnesium incorporation into β-TCP reduced its in vivo resorption by decreasing parathormone production. J Biomed Mater Res A 2012; 101:1986-93. [PMID: 23239606 DOI: 10.1002/jbm.a.34502] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2012] [Revised: 10/05/2012] [Accepted: 10/11/2012] [Indexed: 12/23/2022]
Abstract
Beta-tricalcium phosphate (β-TCP), one of the most widely used bioresorbable materials for bone therapy, can be doped with magnesium ions, generating β-TCMP. The objectives of this work were to evaluate, on a murine dental alveolus grafting model, the biocompatibility of β-TCP and β-TMCP granules by histomorphometric analysis, as well as the impact on plasmatic levels of receptor activator of nuclear factor κB ligand (RANK-L), osteoprotegerin (OPG), osteocalcin, osteopontin, and parathormone (PTH) during bone repair, using Luminex multiplexing technology. After grafting for 42 days, β-TCP grafted group presented higher bioresorption and induced more newly formed bone than β-TCMP (p < 0.05). β-TCP grafting also induced higher plasmatic levels of RANK-L, compared to β-TCMP and control (blood clot) groups at 21st day (p < 0.05). PTH, which remained at low levels in control group, presented a time-dependent increase in grafted groups, attaining significantly higher levels with β-TCP by the 42nd day (p < 0.05). RANK-L/OPG ratio increased on β-TCP group and attained a peak on the 21st day. In conclusion, β-TCP granules were more bioresorbable and osteogenic than β-TCMP granules, and the resorption of both materials might have been affected by osteoclastogenesis modulated by changes in the plasmatic levels of PTH and RANK-L.
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Affiliation(s)
- Debora H Yassuda
- Department of Metallurgy and Materials, Federal University of Rio de Janeiro/COPPE, Rio de Janeiro, RJ, Brazil
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Korostishevsky M, Malkin I, Trofimov S, Pei Y, Deng HW, Livshits G. Significant association between body composition phenotypes and the osteocalcin genomic region in normative human population. Bone 2012; 51:688-94. [PMID: 22842327 PMCID: PMC4450085 DOI: 10.1016/j.bone.2012.07.010] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/17/2012] [Revised: 07/08/2012] [Accepted: 07/16/2012] [Indexed: 12/13/2022]
Abstract
Osteocalcin, a major inorganic component of bone matrix and marker of bone formation, is also involved in regulation of glucose and fat mass metabolism. However, much uncertainty remains about whether the above effect on fat mass has a genetic component. Our main aim was to test whether a variation of body composition phenotypes is associated with BGLAP genomic region variants. To achieve this aim, we used an ethnically homogeneous discovery sample of 230 families consisting of 1112 apparently healthy individuals (561 males and 551 females) of European origin. We conducted association analysis between six SNPs and five obesity-related phenotypes: plasma levels of leptin, anthropometrical fat mass (FM), principal component scores of eight skinfold (SK_PC) and nine circumference (CR_PC) measurements, and body mass index (BMI). Two powerful and robust tools were applied: the pedigree disequilibrium test and variance component models, taking into account both familial and genetic effects. Significant association results were observed for all phenotypes. The most significant results were observed between the haplotype composed of three SNPs (rs2758605-rs1543294-rs2241106) and BMI (p=8.07(-7)), and CR_PC (p=5.29(-5)). The association with BMI was tested and confirmed in our replication study, including 2244 unrelated adult US Caucasians, who were previously assessed for whole genome SNP data. In addition, we obtained an evidence of potential non-additive interactions between the above three SNPs concerning their association with BMI. Bioinformatics sources suggest that the aforementioned interaction could originate from different genetic loci in this region; however, ascertaining the exact circumstances requires a detailed molecular-genetic study.
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Affiliation(s)
- Michael Korostishevsky
- Human Population Biology Research Unit, Department of Anatomy and Anthropology, Tel Aviv University, Tel Aviv, Israel
| | - Ida Malkin
- Human Population Biology Research Unit, Department of Anatomy and Anthropology, Tel Aviv University, Tel Aviv, Israel
| | - Svetlana Trofimov
- Human Population Biology Research Unit, Department of Anatomy and Anthropology, Tel Aviv University, Tel Aviv, Israel
| | - Yufang Pei
- Department of Biostatistics and Bioinformatics, School of Public Health and Tropical Medicine, Tulane University, New Orleans, LA, USA
| | - Hong-Wen Deng
- Department of Biostatistics and Bioinformatics, School of Public Health and Tropical Medicine, Tulane University, New Orleans, LA, USA
| | - Gregory Livshits
- Human Population Biology Research Unit, Department of Anatomy and Anthropology, Tel Aviv University, Tel Aviv, Israel
- Corresponding author at: Department of Anatomy and Anthropology, Sackler Faculty of Medicine, Tel Aviv University, Ramat Aviv, Tel Aviv 69978, Israel. Fax: +972 3 6408287. (G. Livshits)
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10
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Pallu S, Rochefort GY, Jaffre C, Refregiers M, Maurel DB, Benaitreau D, Lespessailles E, Jamme F, Chappard C, Benhamou CL. Synchrotron ultraviolet microspectroscopy on rat cortical bone: involvement of tyrosine and tryptophan in the osteocyte and its environment. PLoS One 2012; 7:e43930. [PMID: 22937127 PMCID: PMC3429417 DOI: 10.1371/journal.pone.0043930] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2012] [Accepted: 07/27/2012] [Indexed: 11/24/2022] Open
Abstract
Alcohol induced osteoporosis is characterized by a bone mass decrease and microarchitecture alterations. Having observed an excess in osteocyte apoptosis, we aimed to assess the bone tissue biochemistry, particularly in the osteocyte and its environment. For this purpose, we used a model of alcohol induced osteoporosis in rats. Bone sections of cortical bone were investigated using synchrotron UV-microspectrofluorescence at subcellular resolution. We show that bone present three fluorescence peaks at 305, 333 and 385 nm, respectively corresponding to tyrosine, tryptophan and collagen. We have determined that tyrosine/collagen and tryptophan/collagen ratios were higher in the strong alcohol consumption group. Tryptophan is related to the serotonin metabolism involved in bone formation, while tyrosine is involved in the activity of tyrosine kinases and phosphatases in osteocytes. Our experiment represents the first combined synchrotron UV microspectroscopy analysis of bone tissue with a quantitative biochemical characterization in the osteocyte and surrounding matrix performed separately.
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Affiliation(s)
- Stéphane Pallu
- Institut National de la Santé et de la Recherche Médicale, INSERM U-658, Université d'Orléans, Orléans, France.
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11
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Lombardi G, Lanteri P, Graziani R, Colombini A, Banfi G, Corsetti R. Bone and energy metabolism parameters in professional cyclists during the Giro d'Italia 3-weeks stage race. PLoS One 2012; 7:e42077. [PMID: 22848709 PMCID: PMC3407078 DOI: 10.1371/journal.pone.0042077] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2012] [Accepted: 07/02/2012] [Indexed: 12/22/2022] Open
Abstract
Cycling is a not weight-bearing activity and is known to induce bone resorption. Stage races are really strenuous endurance performances affecting the energy homeostasis. The recently highlighted link, in the co-regulation of bone and energy metabolism, demonstrates a central role for the equilibrium between carboxylated and undercarboxylated forms of osteocalcin. Aim of this study was to understand the acute physiological responses to a cycling stage race in terms of bone turnover and energy metabolism and the possible co-regulative mechanisms underlying their relationship. We studied nine professional cyclists engaged in 2011 Giro d'Italia stage race. Pre-analytical and analytical phases tightly followed academic and anti-doping authority's recommendations. Bone and energy metabolism markers (bone alkaline phosphatase, tartrate-resistant acid phosphatase 5b, total and undercarboxylated osteocalcin, leptin and adiponectin) and related hormones (cortisol and testosterone) were measured, by Sandwich Enzyme Immunoassays, at days -1 (pre-race), 12 and 22 during the race. The power output and the energy expenditure (mean and accumulated) were derived and correlated with the biochemical indexes. During the race, bone metabolism showed that an unbalance in behalf of resorption, which is enhanced, occurred along with a relative increase in the concentration of the undercarboxylated form of osteocalcin that was indirectly related to the enhanced energy expenditure, through adipokines modifications, with leptin decrease (high energy consumption) and adiponectin increase (optimization of energy expenditure). The exertion due to heavy effort induced a decrease of cortisol, while testosterone levels resulted unchanged. In conclusion, during a 3-weeks stage race, bone metabolism is pushed towards resorption. A possible relationship between the bone and the energy metabolisms is suggested by the relative correlations among absolute and relative concentrations trends of undercarboxylated OC, adipokines concentrations, BMI, fat mass (%), power output and the derived energy expenditure.
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12
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Association Study of Sirtuin 1 Polymorphisms with Bone Mineral Density and Body Mass Index. Arch Med Res 2012; 43:363-8. [DOI: 10.1016/j.arcmed.2012.06.012] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2011] [Accepted: 06/14/2012] [Indexed: 12/22/2022]
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13
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Sullivan TR, Duque G, Keech AC, Herrmann M. An old friend in a new light: the role of osteocalcin in energy metabolism. Cardiovasc Ther 2011; 31:65-75. [PMID: 21975009 DOI: 10.1111/j.1755-5922.2011.00300.x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/16/2023] Open
Abstract
Accumulating evidence suggests interactions between bone and energy metabolism, which may affect the risk of cardiovascular disease. Recent animal studies indicate that osteocalcin (OC) plays a key role in the coordinated regulation of glucose and insulin metabolism while insulin receptors on osteoblasts may regulate bone turnover and circulating OC levels. Association studies, weight loss interventions, and observational data lend some support to the existence and relevance of these mechanisms in humans. However, corroborating evidence from pharmacologic interventions in either bone or glucose metabolism is limited by the number, design, and complex pharmacological effects of the drugs used. Furthermore, such clinical trials are complicated by the alteration of metabolic feedback mechanisms in the insulin resistant state. Purpose-designed studies are needed to further establish the existence and significance of the role of OC and its subfractions in human insulin metabolism. In this review we summarize existing animal evidence regarding the role of OC and its subfractions in bone and energy metabolism and assess current clinical trial evidence relating to the significance and consequences of this relationship in humans.
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Affiliation(s)
- Tim R Sullivan
- Hornsby Kuring-gai Hospital, Northern Sydney Health Service, Hornsby, Australia
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14
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Chappard D, Baslé MF, Legrand E, Audran M. New laboratory tools in the assessment of bone quality. Osteoporos Int 2011; 22:2225-40. [PMID: 21347743 DOI: 10.1007/s00198-011-1573-6] [Citation(s) in RCA: 82] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/26/2010] [Accepted: 01/31/2011] [Indexed: 01/22/2023]
Abstract
Bone quality is a complex set of intricated and interdependent factors that influence bone strength. A number of methods have emerged to measure bone quality, taking into account the organic or the mineral phase of the bone matrix, in the laboratory. Bone quality is a complex set of different factors that are interdependent. The bone matrix organization can be described at five different levels of anatomical organization: nature (organic and mineral), texture (woven or lamellar), structure (osteons in the cortices and arch-like packets in trabecular bone), microarchitecture, and macroarchitecture. Any change in one of these levels can alter bone quality. An altered bone remodeling can affect bone quality by influencing one or more of these factors. We have reviewed here the main methods that can be used in the laboratory to explore bone quality on bone samples. Bone remodeling can be evaluated by histomorphometry; microarchitecture is explored in 2D on histological sections and in 3D by microCT or synchrotron. Microradiography and scanning electron microscopy in the backscattered electron mode can measure the mineral distribution; Raman and Fourier-transformed infra-red spectroscopy and imaging can simultaneously explore the organic and mineral phase of the matrix on multispectral images; scanning acoustic microscopy and nanoindentation provide biomechanical information on individual trabeculae. Finally, some histological methods (polarization, surface staining, fluorescence, osteocyte staining) may also be of interest in the understanding of quality as a component of bone fragility. A growing number of laboratory techniques are now available. Some of them have been described many years ago and can find a new youth; others having benefited from improvements in physical and computer techniques are now available.
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Affiliation(s)
- D Chappard
- INSERM, U922-IRIS-IBS Institut de Biologie en Santé, CHU d'Angers, 49933, Angers, France.
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15
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Ducy P. The role of osteocalcin in the endocrine cross-talk between bone remodelling and energy metabolism. Diabetologia 2011; 54:1291-7. [PMID: 21503740 DOI: 10.1007/s00125-011-2155-z] [Citation(s) in RCA: 143] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/14/2010] [Accepted: 03/17/2011] [Indexed: 02/05/2023]
Abstract
Bone remodelling, which maintains bone mass constant during adulthood, is an energy-demanding process. This, together with the observation that the adipocyte-derived hormone leptin is a major inhibitor of bone remodelling, led to the hypothesis that bone cells regulate energy metabolism through an endocrine mechanism. Studies to test this hypothesis identified osteocalcin, a hormone secreted by osteoblasts, as a positive regulator of insulin secretion, insulin resistance and energy expenditure. Remarkably, insulin signalling in osteoblasts is a positive regulator of osteocalcin production and activation via its ability to indirectly enhance bone resorption by osteoclasts. In contrast, leptin is a potent inhibitor of osteocalcin function through its effect on the sympathetic tone. Hence, osteocalcin is part of a complex signalling network between bone and the organs more classically associated with the regulation of energy homeostasis, such as the pancreas and adipose tissue. This review summarises the molecular and cellular bases of the present knowledge on osteocalcin biology and discusses the potential relevance of osteocalcin to human metabolism and pathology.
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Affiliation(s)
- P Ducy
- Department of Pathology and Cell Biology, Columbia University Medical Center, New York, NY 10032, USA.
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5-HT and bone biology. Curr Opin Pharmacol 2011; 11:34-8. [PMID: 21320797 DOI: 10.1016/j.coph.2011.01.007] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2010] [Revised: 01/26/2011] [Accepted: 01/26/2011] [Indexed: 12/20/2022]
Abstract
Bone formation and bone resorption, the two processes occurring constantly and in a balanced fashion throughout the skeleton, are regulated by signals as various as local and low range growth factors, hormones, and neuronal outputs. Adding to the long list of molecules involved in these regulations, gut-derived and brain-derived serotonin were recently shown to control one or both of these processes. They do so, however, by targeting different cells, respectively acting as a hormone and as a neuromediator. Moreover, while brain serotonin positively regulates bone mass accrual peripheral serotonin is a potent inhibitor of bone formation. These findings raise the prospect that pharmacologically manipulating serotonin production could therefore become a novel strategy to treat bone loss disorders.
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