1
|
Wee NKY, de Lima TFC, McGregor NE, Walker EC, Poulton IJ, Blank M, Sims NA. Leptin receptor in osteocytes promotes cortical bone consolidation in female mice. J Endocrinol 2022; 255:25-37. [PMID: 35938692 DOI: 10.1530/joe-22-0084] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/03/2022] [Accepted: 08/01/2022] [Indexed: 11/08/2022]
Abstract
Bone strength is partially determined during cortical bone consolidation, a process comprising coalescence of peripheral trabecular bone and its progressive mineralisation. Mice with genetic deletion of suppressor of cytokine signalling 3 (Socs3), an inhibitor of STAT3 signalling, exhibit delayed cortical bone consolidation, indicated by high cortical porosity, low mineral content, and low bone strength. Since leptin receptor (LepR) is expressed in the osteoblast lineage and is suppressed by SOCS3, we evaluated whether LepR deletion in osteocytes would rectify the Dmp1cre.Socs3fl/fl bone defect. First, we tested LepR deletion in osteocytes by generating Dmp1cre.LepRfl/fl mice and detected no significant bone phenotype. We then generated Dmp1cre.Socs3fl/fl.LepRfl/fl mice and compared them to Dmp1cre.Socs3fl/fl controls. Between 6 and 12 weeks of age, both Dmp1cre.Socs3fl/fl.LepRfl/fl and control (Dmp1cre.Socs3fl/fl) mice showed an increasing proportion of more heavily mineralised bone, indicating some cortical consolidation with time. However, at 12 weeks of age, rather than resolving the phenotype, delayed consolidation was extended in female Dmp1cre.Socs3fl/fl.LepRfl/fl mice. This was indicated in both metaphysis and diaphysis by greater proportions of low-density bone, lower proportions of high-density bone, and greater cortical porosity than Dmp1cre.Socs3fl/fl controls. There was also no change in the proportion of osteocytes staining positive for phospho-STAT3, suggesting the effect of LepR deletion in Dmp1cre.Socs3fl/fl mice is STAT3-independent. This identifies a new role for leptin signalling in bone which opposes our original hypothesis. Although LepR in osteocytes has no irreplaceable physiological role in normal bone maturation, when STAT3 is hyperactive, LepR in Dmp1Cre-expressing cells supports cortical consolidation.
Collapse
Affiliation(s)
- Natalie K Y Wee
- Bone Cell Biology and Disease Unit, St Vincent's Institute of Medical Research, Fitzroy, Australia
| | - Thaísa F C de Lima
- Bone Cell Biology and Disease Unit, St Vincent's Institute of Medical Research, Fitzroy, Australia
- Department of Genetics and Molecular Biology, University of Campinas, São Paulo, Brazil
| | - Narelle E McGregor
- Bone Cell Biology and Disease Unit, St Vincent's Institute of Medical Research, Fitzroy, Australia
| | - Emma C Walker
- Bone Cell Biology and Disease Unit, St Vincent's Institute of Medical Research, Fitzroy, Australia
| | - Ingrid J Poulton
- Bone Cell Biology and Disease Unit, St Vincent's Institute of Medical Research, Fitzroy, Australia
| | - Martha Blank
- Bone Cell Biology and Disease Unit, St Vincent's Institute of Medical Research, Fitzroy, Australia
- Department of Medicine, The University of Melbourne, St. Vincent's Hospital, Melbourne, Australia
| | - Natalie A Sims
- Bone Cell Biology and Disease Unit, St Vincent's Institute of Medical Research, Fitzroy, Australia
- Department of Medicine, The University of Melbourne, St. Vincent's Hospital, Melbourne, Australia
| |
Collapse
|
2
|
Traver C, Miralles L, Barcia JM. Association between Molecular Mechanisms and Tooth Eruption in Children with Obesity. CHILDREN 2022; 9:children9081209. [PMID: 36010098 PMCID: PMC9406572 DOI: 10.3390/children9081209] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/25/2022] [Revised: 08/03/2022] [Accepted: 08/08/2022] [Indexed: 11/16/2022]
Abstract
Different works have reported earlier permanent teething in obese/overweight children compared to control ones. In contrast, others have reported a delayed permanent teething in undernutrition/underweight children compared to control one. It has been reported that becoming overweight or suffering from obesity can increase gingival pro-inflammatory drive and can affect orthodontic treatment (among other complications). In this sense, little is known about the molecular mechanisms affecting dental eruption timing. Leptin and adiponectin are adipocytokines signaling molecules released in overweight and underweight conditions, respectively. These adipocytokines can modulate osteocyte, odontoblast, and cementoblast activity, even regulating dental lamina initiation. The present review focuses on the molecular approach wherein leptin and adiponectin act as modulators of Runt-related transcription factor 2 (Runx 2) gene regulating dental eruption timing.
Collapse
Affiliation(s)
- Carla Traver
- Department of Dentistry, Catholic University of Valencia San Vicente Mártir, 46001 Valencia, Spain
- Doctoral School, Catholic University of Valencia San Vicente Mártir, 46001 Valencia, Spain
- Correspondence:
| | - Lucía Miralles
- Department of Dentistry, Catholic University of Valencia San Vicente Mártir, 46001 Valencia, Spain
| | - Jorge Miguel Barcia
- Department of Anatomy and Physiology, Catholic University of Valencia San Vicente Mártir, 46001 Valencia, Spain
| |
Collapse
|
3
|
Ibelli AMG, Peixoto JDO, Zanella R, Gouveia JJDS, Cantão ME, Coutinho LL, Marchesi JAP, Pizzol MSD, Marcelino DEP, Ledur MC. Downregulation of growth plate genes involved with the onset of femoral head separation in young broilers. Front Physiol 2022; 13:941134. [PMID: 36003650 PMCID: PMC9393217 DOI: 10.3389/fphys.2022.941134] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2022] [Accepted: 07/08/2022] [Indexed: 11/13/2022] Open
Abstract
Femoral head separation (FHS) is characterized by the detachment of growth plate (GP) and articular cartilage, occurring in tibia and femur. However, the molecular mechanisms involved with this condition are not completely understood. Therefore, genes and biological processes (BP) involved with FHS were identified in 21-day-old broilers through RNA sequencing of the femoral GP. 13,487 genes were expressed in the chicken femoral head transcriptome of normal and FHS-affected broilers. From those, 34 were differentially expressed (DE; FDR ≤0.05) between groups, where all of them were downregulated in FHS-affected broilers. The main BP were enriched in receptor signaling pathways, ossification, bone mineralization and formation, skeletal morphogenesis, and vascularization. RNA-Seq datasets comparison of normal and FHS-affected broilers with 21, 35 and 42 days of age has shown three shared DE genes (FBN2, C1QTNF8, and XYLT1) in GP among ages. Twelve genes were exclusively DE at 21 days, where 10 have already been characterized (SHISA3, FNDC1, ANGPTL7, LEPR, ENSGALG00000049529, OXTR, ENSGALG00000045154, COL16A1, RASD2, BOC, GDF10, and THSD7B). Twelve SNPs were associated with FHS (p < 0.0001). Out of those, 5 were novel and 7 were existing variants located in 7 genes (RARS, TFPI2, TTI1, MAP4K3, LINK54, and AREL1). We have shown that genes related to chondrogenesis and bone differentiation were downregulated in the GP of FHS-affected young broilers. Therefore, these findings evince that candidate genes pointed out in our study are probably related to the onset of FHS in broilers.
Collapse
Affiliation(s)
- Adriana Mércia Guaratini Ibelli
- Embrapa Suínos e Aves, Concórdia, Brazil
- Programa de Pós-Graduação em Ciências Veterinárias, Universidade Estadual do Centro-Oeste, Guarapuava, Brazil
| | - Jane de Oliveira Peixoto
- Embrapa Suínos e Aves, Concórdia, Brazil
- Programa de Pós-Graduação em Ciências Veterinárias, Universidade Estadual do Centro-Oeste, Guarapuava, Brazil
| | | | | | | | - Luiz Lehmann Coutinho
- Laboratório de Biotecnologia Animal, Escola Superior de Agricultura “Luiz de Queiroz”, Universidade de SP, Piracicaba, Brazil
| | | | | | | | - Mônica Corrêa Ledur
- Embrapa Suínos e Aves, Concórdia, Brazil
- Programa de Pós-Graduação Em Zootecnia, Universidade do Estado de SC, UDESC-Oeste, Chapecó, Brazil
- *Correspondence: Mônica Corrêa Ledur,
| |
Collapse
|
4
|
Shochat C, Wang Z, Mo C, Nelson S, Donaka R, Huang J, Karasik D, Brotto M. Deletion of SREBF1, a Functional Bone-Muscle Pleiotropic Gene, Alters Bone Density and Lipid Signaling in Zebrafish. Endocrinology 2021; 162:5929645. [PMID: 33068391 PMCID: PMC7745669 DOI: 10.1210/endocr/bqaa189] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/27/2020] [Indexed: 12/30/2022]
Abstract
Through a genome-wide analysis of bone mineral density (BMD) and muscle mass, identification of a signaling pattern on 17p11.2 recognized the presence of sterol regulatory element-binding factor 1 (SREBF1), a gene responsible for the regulation of lipid homeostasis. In conjunction with lipid-based metabolic functions, SREBF1 also codes for the protein, SREBP-1, a transcription factor known for its role in adipocyte differentiation. We conducted a quantitative correlational study. We established a zebrafish (ZF) SREBF1 knockout (KO) model and used a targeted customized lipidomics approach to analyze the extent of SREBF1 capabilities. For lipidomics profiling, we isolated the dorsal muscles of wild type (WT) and KO fishes, and we performed liquid chromatography-tandem mass spectrometry screening assays of these samples. In our analysis, we profiled 48 lipid mediators (LMs) derived from various essential polyunsaturated fatty acids to determine potential targets regulated by SREBF1, and we found that the levels of 11,12 epoxyeicosatrienoic acid (11,12-EET) were negatively associated with the number of SREBF1 alleles (P = 0.006 for a linear model). We also compared gene expression between KO and WT ZF by genome-wide RNA-sequencing. Significantly enriched pathways included fatty acid elongation, linoleic acid metabolism, arachidonic acid metabolism, adipocytokine signaling, and DNA replication. We discovered trends indicating that BMD in adult fish was significantly lower in the KO than in the WT population (P < 0.03). These studies reinforce the importance of lipidomics investigation by detailing how the KO of SREBF1 affects both BMD and lipid-signaling mediators, thus confirming the importance of SREBF1 for musculoskeletal homeostasis.
Collapse
Affiliation(s)
- Chen Shochat
- Azrieli Faculty of Medicine, Bar-Ilan University, Safed, Israel
| | - Zhiying Wang
- Bone-Muscle Research Center, College of Nursing & Health Innovation, University of Texas at Arlington-UTA, Arlington, Texas
| | - Chenglin Mo
- Bone-Muscle Research Center, College of Nursing & Health Innovation, University of Texas at Arlington-UTA, Arlington, Texas
| | - Sarah Nelson
- Bone-Muscle Research Center, College of Nursing & Health Innovation, University of Texas at Arlington-UTA, Arlington, Texas
| | | | - Jian Huang
- Bone-Muscle Research Center, College of Nursing & Health Innovation, University of Texas at Arlington-UTA, Arlington, Texas
| | - David Karasik
- Azrieli Faculty of Medicine, Bar-Ilan University, Safed, Israel
- Correspondence: David Karasik, Azrieli Faculty of Medicine, Bar-Ilan university, Safed, 1311502, Israel. E-mail:
| | - Marco Brotto
- Bone-Muscle Research Center, College of Nursing & Health Innovation, University of Texas at Arlington-UTA, Arlington, Texas
| |
Collapse
|
5
|
Ruiz-Heiland G, Yong JW, von Bremen J, Ruf S. Leptin reduces in vitro cementoblast mineralization and survival as well as induces PGE2 release by ERK1/2 commitment. Clin Oral Investig 2020; 25:1933-1944. [PMID: 32820432 PMCID: PMC7965856 DOI: 10.1007/s00784-020-03501-3] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2020] [Accepted: 08/05/2020] [Indexed: 12/18/2022]
Abstract
Objectives Juvenile obesity is a complex clinical condition that is present more and more frequently in the daily orthodontic practice. Over-weighted patients have an impaired bone metabolism, due in part to their increased levels of circulating adipokines. Particularly, leptin has been reported to play a key role in bone physiology. Leptin is ubiquitously present in the body, including blood, saliva, and crevicular fluid. If, and to what extent, it could influence the reaction of cementoblasts during orthodontic-induced forces is yet unknown. Material and methods OCCM-30 cementoblasts were cultivated under compressive forces using different concentrations of leptin. The expression of ObR, Runx-2, Osteocalcin, Rank-L, Sost, Caspase 3, 8, and 9 were analyzed by RT-PCR. Western blots were employed for protein analysis. The ERK1/2 antagonist FR180204 (Calbiochem) was used and cPLA2 activation, PGE2, and cytochrome C release were further evaluated. Results In vitro, when compressive forces are applied, leptin promotes ERK1/2 phosphorylation, as well as upregulates PGE2 and caspase 3 and caspase 9 on OCCM cells. Blockade of ERK1/2 impairs leptin-induced PGE2 secretion and reduced caspase 3 and caspase 9 expression. Conclusions Leptin influences the physiological effect of compressive forces on cementoblasts, exerting in vitro a pro-inflammatory and pro-apoptotic effect. Clinical relevance Our findings indicate that leptin exacerbates the physiological effect of compressive forces on cementoblasts promoting the release of PGE2 and increases the rate of cell apoptosis, and thus, increased levels of leptin may influence the inflammatory response during orthodontically induced tooth movement.
Collapse
Affiliation(s)
- G Ruiz-Heiland
- Department of Orthodontics, University of Giessen, Schlangenzahl 14, 35392, Giessen, Germany.
| | - J W Yong
- Department of Orthodontics, University of Giessen, Schlangenzahl 14, 35392, Giessen, Germany
| | - J von Bremen
- Department of Orthodontics, University of Giessen, Schlangenzahl 14, 35392, Giessen, Germany
| | - S Ruf
- Department of Orthodontics, University of Giessen, Schlangenzahl 14, 35392, Giessen, Germany
| |
Collapse
|
6
|
Keune JA, Branscum AJ, Wong CP, Iwaniec UT, Turner RT. Effect of Leptin Deficiency on the Skeletal Response to Hindlimb Unloading in Adult Male Mice. Sci Rep 2019; 9:9336. [PMID: 31249331 PMCID: PMC6597714 DOI: 10.1038/s41598-019-45587-0] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2018] [Accepted: 06/06/2019] [Indexed: 12/29/2022] Open
Abstract
Based on body weight, morbidly obese leptin-deficient ob/ob mice have less bone than expected, suggesting that leptin plays a role in the skeletal response to weight bearing. To evaluate this possibility, we compared the skeletal response of wild type (WT) and ob/ob mice to hindlimb unloading (HU). Mice were individually housed at 32 °C (thermoneutral) from 4 weeks of age (rapidly growing) to 16 weeks of age (approaching skeletal maturity). Mice were then randomized into one of 4 groups (n = 10/group): (1) WT control, (2) WT HU, (3) ob/ob control, and (4) ob/ob HU and the results analyzed by 2-way ANOVA. ob/ob mice pair-fed to WT mice had normal cancellous bone volume fraction (BV/TV) in distal femur, lower femur length and total bone area, mineral content (BMC) and density (BMD), and higher cancellous bone volume fraction in lumbar vertebra (LV). HU resulted in lower BMC and BMD in total femur, and lower BV/TV in distal femur and LV in both genotypes. Cancellous bone loss in femur in both genotypes was associated with increases in osteoclast-lined bone perimeter. In summary, leptin deficiency did not attenuate HU-induced osteopenia in male mice, suggesting that leptin is not required for bone loss induced by unweighting.
Collapse
Affiliation(s)
- Jessica A. Keune
- 0000 0001 2112 1969grid.4391.fSkeletal Biology Laboratory, School of Biological and Population Health Sciences, Oregon State University, Corvallis, OR 97331 USA
| | - Adam J. Branscum
- 0000 0001 2112 1969grid.4391.fBiostatistics Program, School of Biological and Population Health Sciences, Oregon State University, Corvallis, OR 97331 USA
| | - Carmen P. Wong
- 0000 0001 2112 1969grid.4391.fSkeletal Biology Laboratory, School of Biological and Population Health Sciences, Oregon State University, Corvallis, OR 97331 USA
| | - Urszula T. Iwaniec
- 0000 0001 2112 1969grid.4391.fSkeletal Biology Laboratory, School of Biological and Population Health Sciences, Oregon State University, Corvallis, OR 97331 USA ,0000 0001 2112 1969grid.4391.fCenter for Healthy Aging Research, Oregon State University, Corvallis, OR 97331 USA
| | - Russell T. Turner
- 0000 0001 2112 1969grid.4391.fSkeletal Biology Laboratory, School of Biological and Population Health Sciences, Oregon State University, Corvallis, OR 97331 USA ,0000 0001 2112 1969grid.4391.fCenter for Healthy Aging Research, Oregon State University, Corvallis, OR 97331 USA
| |
Collapse
|
7
|
Song J, Ye B, Liu H, Bi R, Zhang N, Hu J, Luo E. Fak-Mapk, Hippo and Wnt signalling pathway expression and regulation in distraction osteogenesis. Cell Prolif 2018; 51:e12453. [PMID: 29504176 PMCID: PMC6528869 DOI: 10.1111/cpr.12453] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2017] [Accepted: 01/27/2018] [Indexed: 02/05/2023] Open
Abstract
OBJECTIVES To investigate the mechanism of mechanical stimulation in bone formation and regeneration during distraction osteogenesis. MATERIALS AND METHODS In this study, microarray technology was used to investigate the time course of bone-related molecular changes in distraction osteogenesis in rats. Real-time PCR and Western-blot analyses were used to confirm the expression of genes identified in microarrays. Meanwhile, we used a lentivirus vector to inhibit Fak expression, in order to identify the osteogenic effect of Fak and Fak-Mapk pathway during distraction osteogenesis. RESULTS Several components of the Wnt and Hippo pathways were found to be up- or down-regulated during distraction osteogenesis by microarray. Meanwhile, it was found that Fak, Src, Raf-1, Erk1, Jnk and p38-Mapk were up-regulated during gradual distraction, compared with consolidation. To further determine whether Fak-Mapk pathway played an important role in distraction osteogenesis, Fak was disrupted with a lentivirus vector. The expressions levels of p-Fak, p-Erk1/2, p-JNK and p-p38Mapk were decreased. Meanwhile, a poor early and late osteogenesis effect was found in the shRNA-Fak group. CONCLUSION It was inferred that the mechanical stimulus induces increased expression of Fak and activates Fak-Mapk pathway, by activation of Erk, Jnk and p38-Mapk pathway, and that Fak at least, in part, plays an important role in maintaining osteogenic effect by activating Fak-Mapk pathway during distraction osteogenesis.
Collapse
Affiliation(s)
- Jian Song
- State Key Laboratory of Oral Diseases & National Clinical Research Center for Oral DiseasesDepartment of oral and Maxillofacial SurgeryWest China Hospital of StomatologySichuan UniversityChengduChina
| | - Bin Ye
- State Key Laboratory of Oral Diseases & National Clinical Research Center for Oral DiseasesDepartment of oral and Maxillofacial SurgeryWest China Hospital of StomatologySichuan UniversityChengduChina
| | - Hanghang Liu
- State Key Laboratory of Oral Diseases & National Clinical Research Center for Oral DiseasesDepartment of oral and Maxillofacial SurgeryWest China Hospital of StomatologySichuan UniversityChengduChina
| | - Ruiye Bi
- State Key Laboratory of Oral Diseases & National Clinical Research Center for Oral DiseasesDepartment of oral and Maxillofacial SurgeryWest China Hospital of StomatologySichuan UniversityChengduChina
| | - Nian Zhang
- State Key Laboratory of Oral Diseases & National Clinical Research Center for Oral DiseasesDepartment of oral and Maxillofacial SurgeryWest China Hospital of StomatologySichuan UniversityChengduChina
| | - Jing Hu
- State Key Laboratory of Oral Diseases & National Clinical Research Center for Oral DiseasesDepartment of oral and Maxillofacial SurgeryWest China Hospital of StomatologySichuan UniversityChengduChina
| | - En Luo
- State Key Laboratory of Oral Diseases & National Clinical Research Center for Oral DiseasesDepartment of oral and Maxillofacial SurgeryWest China Hospital of StomatologySichuan UniversityChengduChina
| |
Collapse
|
8
|
Chen S, Zhu H, Wang G, Xie Z, Wang J, Chen J. Combined use of leptin and mechanical stress has osteogenic effects on ossification of the posterior longitudinal ligament. EUROPEAN SPINE JOURNAL : OFFICIAL PUBLICATION OF THE EUROPEAN SPINE SOCIETY, THE EUROPEAN SPINAL DEFORMITY SOCIETY, AND THE EUROPEAN SECTION OF THE CERVICAL SPINE RESEARCH SOCIETY 2018; 27:1757-1766. [PMID: 29909551 DOI: 10.1007/s00586-018-5663-4] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/14/2017] [Revised: 03/04/2018] [Accepted: 06/06/2018] [Indexed: 11/26/2022]
Abstract
PURPOSE To evaluate the effects of leptin/leptin receptor (LepR) combined with mechanical stress on the development of ossification of the posterior longitudinal ligament (OPLL), which is a disease characterized by ectopic bone formation of the posterior longitudinal ligament (PLL) and can lead to radiculopathy and myelopathy. METHODS Six human samples of the PLL were analyzed for the expression of leptin and LepR by RT-PCR and western blotting. PLL cells were stimulated with leptin and mechanical stress delivered via a Flexcell tension system, and osteogenic differentiation was evaluated by RT-PCR and western blotting analysis of osteogenic marker expression as well as by alkaline phosphatase (ALP) staining and alizarin red S staining. Activation of mitogen-activated protein kinase (MAPK), Janus kinase (JAK) 2-signal transducer, activator of transcription (STAT) 3 and phosphatidylinositol 3-kinase (PI3K)-Akt was evaluated by western blotting. RESULTS Samples from the OPLL group had higher LepR mRNA and protein levels and lower leptin levels than those from healthy controls. Exposure to leptin and Flexcell increased the number of ALP-positive cells and calcium nodules in a dose-dependent manner; this effect was accompanied by upregulation of the osteogenic markers osteocalcin, runt-related transcription factor 2 (RUNX2) and osteopontin. Extracellular signal-regulated kinase, P38 MAPK, JAK2, STAT3, PI3K and Akt signaling, was also activated by the combined effects of leptin and mechanical stress. CONCLUSIONS Leptin and LepR are differentially expressed in OPLL tissues, and the combined use of leptin/LepR and mechanical stress promotes osteogenic differentiation of PLL cells via MAPK, JAK2-STAT3 and PI3K/Akt signaling. These slides can be retrieved under Electronic Supplementary Material.
Collapse
Affiliation(s)
- Shuai Chen
- Department of Orthopaedic Surgery, Sir Run Run Shaw Hospital, School of Medicine, Zhejiang University, 3 East Qingchun Road, Hangzhou, 310020, China
- Key Laboratory of Biotherapy of Zhejiang Province, Hangzhou, China
| | - Haifeng Zhu
- Department of Orthopaedic Surgery, Sir Run Run Shaw Hospital, School of Medicine, Zhejiang University, 3 East Qingchun Road, Hangzhou, 310020, China
- Key Laboratory of Biotherapy of Zhejiang Province, Hangzhou, China
| | - Gangliang Wang
- Department of Orthopaedic Surgery, Sir Run Run Shaw Hospital, School of Medicine, Zhejiang University, 3 East Qingchun Road, Hangzhou, 310020, China
- Key Laboratory of Biotherapy of Zhejiang Province, Hangzhou, China
| | - Ziang Xie
- Department of Orthopaedic Surgery, Sir Run Run Shaw Hospital, School of Medicine, Zhejiang University, 3 East Qingchun Road, Hangzhou, 310020, China
- Key Laboratory of Biotherapy of Zhejiang Province, Hangzhou, China
| | - Jiying Wang
- Key Laboratory of Biotherapy of Zhejiang Province, Hangzhou, China
| | - Jian Chen
- Department of Orthopaedic Surgery, Sir Run Run Shaw Hospital, School of Medicine, Zhejiang University, 3 East Qingchun Road, Hangzhou, 310020, China.
- Key Laboratory of Biotherapy of Zhejiang Province, Hangzhou, China.
| |
Collapse
|
9
|
Turko AJ, Kültz D, Fudge D, Croll RP, Smith FM, Stoyek MR, Wright PA. Skeletal stiffening in an amphibious fish out of water is a response to increased body weight. ACTA ACUST UNITED AC 2018; 220:3621-3631. [PMID: 29046415 DOI: 10.1242/jeb.161638] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2017] [Accepted: 08/07/2017] [Indexed: 01/06/2023]
Abstract
Terrestrial animals must support their bodies against gravity, while aquatic animals are effectively weightless because of buoyant support from water. Given this evolutionary history of minimal gravitational loading of fishes in water, it has been hypothesized that weight-responsive musculoskeletal systems evolved during the tetrapod invasion of land and are thus absent in fishes. Amphibious fishes, however, experience increased effective weight when out of water - are these fishes responsive to gravitational loading? Contrary to the tetrapod-origin hypothesis, we found that terrestrial acclimation reversibly increased gill arch stiffness (∼60% increase) in the amphibious fish Kryptolebias marmoratus when loaded normally by gravity, but not under simulated microgravity. Quantitative proteomics analysis revealed that this change in mechanical properties occurred via increased abundance of proteins responsible for bone mineralization in other fishes as well as in tetrapods. Type X collagen, associated with endochondral bone growth, increased in abundance almost ninefold after terrestrial acclimation. Collagen isoforms known to promote extracellular matrix cross-linking and cause tissue stiffening, such as types IX and XII collagen, also increased in abundance. Finally, more densely packed collagen fibrils in both gill arches and filaments were observed microscopically in terrestrially acclimated fish. Our results demonstrate that the mechanical properties of the fish musculoskeletal system can be fine-tuned in response to changes in effective body weight using biochemical pathways similar to those in mammals, suggesting that weight sensing is an ancestral vertebrate trait rather than a tetrapod innovation.
Collapse
Affiliation(s)
- Andy J Turko
- Department of Integrative Biology, University of Guelph, 50 Stone Road East, Guelph, ON, Canada N1G 2W1
| | - Dietmar Kültz
- Department of Animal Sciences, University of California, Davis, 1 Shields Ave., Meyer Hall, Davis, CA 95616, USA
| | - Douglas Fudge
- Department of Integrative Biology, University of Guelph, 50 Stone Road East, Guelph, ON, Canada N1G 2W1.,Schmid College of Science and Technology, Chapman University, 1 University Dr., Orange, CA 92866, USA
| | - Roger P Croll
- Department of Physiology and Biophysics, Dalhousie University, 5850 College Street, Halifax, Nova Scotia, Canada B3H 4R2
| | - Frank M Smith
- Department of Medical Neuroscience, Dalhousie University, 5850 College Street, Halifax, Nova Scotia, Canada B3H 4R2
| | - Matthew R Stoyek
- Department of Physiology and Biophysics, Dalhousie University, 5850 College Street, Halifax, Nova Scotia, Canada B3H 4R2.,Department of Medical Neuroscience, Dalhousie University, 5850 College Street, Halifax, Nova Scotia, Canada B3H 4R2
| | - Patricia A Wright
- Department of Integrative Biology, University of Guelph, 50 Stone Road East, Guelph, ON, Canada N1G 2W1
| |
Collapse
|
10
|
Abstract
PURPOSE OF REVIEW The goal of this review is to gain a better understanding of marrow adipocyte development, its regulation of energy, and its characterization responsible for bone homeostasis. RECENT FINDINGS Despite major advances in uncovering the complex association of bone-fat in the marrow, the underlying basic biological process of adipose tissue development, as well as its interaction with bone homeostasis in pathophysiological conditions, is still not well understood. This review identifies many pro- and anti-osteogenic factors secreted by adipocytes to play a role in the manipulating the fate of mesenchymal stem cells as well as the osteoblastic activity during bone remodeling. It also addresses the function of adipose tissue capable of negative regulation of the hematopoietic microenvironment to influence the bone quantity and the nature of bone homeostasis.
Collapse
Affiliation(s)
- Jillian Cornish
- Department of Medicine, Faculty of Medical and Health Sciences, University of Auckland, 85 Park Road Grafton, Auckland, New Zealand.
| | - Tao Wang
- Department of Medicine, Faculty of Medical and Health Sciences, University of Auckland, 85 Park Road Grafton, Auckland, New Zealand
| | - Jian-Ming Lin
- Department of Medicine, Faculty of Medical and Health Sciences, University of Auckland, 85 Park Road Grafton, Auckland, New Zealand
| |
Collapse
|
11
|
Chen SM, Peng YJ, Wang CC, Su SL, Salter DM, Lee HS. Dexamethasone Down-regulates Osteocalcin in Bone Cells through Leptin Pathway. Int J Med Sci 2018; 15:507-516. [PMID: 29559840 PMCID: PMC5859774 DOI: 10.7150/ijms.21881] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/12/2017] [Accepted: 01/05/2018] [Indexed: 01/26/2023] Open
Abstract
Glucocorticoid therapy, especially at higher doses, is associated with significant adverse side effects including osteoporosis. Leptin, secreted from adipose tissue, has diverse effects on bone tissue regulation. As glucocorticoids stimulate leptin synthesis and secretion directly in adipose tissue we hypothesised that dexamethasone (DEX) induced osteoporosis may, in part, be mediated by an osteoblast dependent leptin-leptin receptor pathway. Human bone cells expressed leptin and leptin receptors (Ob-Ra and Ob-Rb). DEX increased leptin, Ob-Ra and Ob-Rb expression in a dose-dependent manner while decreasing expression of osteocalcin. In the presence of leptin, Cbfa1 and osteonectin expression showed no significant change, whereas osteocalcin expression was decreased. Recombinant human quadruple antagonist leptin suppressed DEX-induced osteocalcin downregulation. The signaling pathway involved up-regulation of JAK2. In conclusion, upregulation of leptin and Ob-Rb in human bone cells by DEX is associated with down-regulation of osteocalcin expression. The down regulation of osteocalcin by DEX was partially through a leptin autocrine/paracrine loop. Adverse effects of DEX on the skeleton may be modified by targeting leptin signaling pathways.
Collapse
Affiliation(s)
- Shu-Mei Chen
- Department of Pathology and Laboratory Medicine, Kaohsiung Veterans General Hospital, Kaohsiung, Taiwan, ROC.,Division of Nephrology, Department of Internal Medicine, Tri-Service General Hospital, Taipei, Taiwan, ROC
| | - Yi-Jen Peng
- Department of Pathology, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan, ROC
| | - Chih-Chien Wang
- Department of Orthopedics, Taipei Medical University Hospital, Taipei, Taiwan, ROC
| | - Sui-Lung Su
- School of Public Health, National Defense Medical Center, Taipei, Taiwan, ROC
| | - Donald M Salter
- Centre for Genomic and Molecular Medicine, IGMM, University of Edinburgh, Edinburgh, UK
| | - Herng-Sheng Lee
- Department of Pathology and Laboratory Medicine, Kaohsiung Veterans General Hospital, Kaohsiung, Taiwan, ROC
| |
Collapse
|
12
|
Lau KHW, Stiffel VM, Rundle CH, Amoui M, Tapia J, White TD, Sheng MHC. Conditional Disruption of miR17~92 in Osteoclasts Led to Activation of Osteoclasts and Loss of Trabecular Bone In Part Through Suppression of the miR17-Mediated Downregulation of Protein-Tyrosine Phosphatase-oc in Mice. JBMR Plus 2017; 1:73-85. [PMID: 29082358 PMCID: PMC5656011 DOI: 10.1002/jbm4.10014] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
This study sought to understand the regulation of an osteoclastic protein-tyrosine phosphatase (PTP-oc), a positive regulator of osteoclast activaty. Our past studies suggested that PTP-oc is regulated post-transcriptionally. The 3'-UTR of PTP-oc mRNA contains a target site for miR17. During osteoclastic differentiation, there was an inverse relationship between the cellular levels of miR17 (expressed as one of the six cluster genes of miR17~92) and PTP-oc mRNA. Overexpression of pre-miR17~92 in mouse osteoclast precursors reduced PTP-oc mRNA level and the size of the derived osteoclasts; whereas deletion of miR17~92 or inhibition of miR17 resulted in the formation of larger osteoclasts containing more nuclei that expressed higher PTP-oc mRNA levels and created larger resorption pits. Thus, PTP-oc-mediated osteoclast activation is modulated in part by miR17~92, particularly miR17. The miR17~92 osteoclast conditional knockout (cKO) mutants, generated by breeding miR17~92loxp/loxp mice with Ctsk-Cre mice, had lower Tb.BV/TV, Tb.BMD, Tb.Conn-Dens, Tb.N, and Tb.Th, but larger Tb.Sp, and greater bone resorption without a change in bone formation compared to littermate controls. The cKO marrow-derived osteoclasts were twice as large, contained twice as many nuclei, and produced twice as large resorption pits as osteoclasts of littermate controls. The expression of genes associated with osteoclast activation was increased in cKO osteoclasts, suggesting that deletion of miR17~92 in osteoclasts promotes osteoclast activation. The cKO osteoblasts did not show differences in cellular miR17 level, alkaline phosphatase activity, and bone nodule formation ability. In conclusion, miR17-92 negatively regulates the osteoclast activity, in part via the miR17-mediated suppression of PTP-oc in osteoclasts.
Collapse
Affiliation(s)
- Kin-Hing William Lau
- Musculoskeletal Disease Center, Jerry L. Pettis Memorial V.A. Medical Center, Loma Linda, California 92357, U.S.A.,Department of Medicine, Loma Linda University School of Medicine, Loma Linda, California 92350, U.S.A
| | - Virginia M Stiffel
- Musculoskeletal Disease Center, Jerry L. Pettis Memorial V.A. Medical Center, Loma Linda, California 92357, U.S.A
| | - Charles H Rundle
- Musculoskeletal Disease Center, Jerry L. Pettis Memorial V.A. Medical Center, Loma Linda, California 92357, U.S.A.,Department of Medicine, Loma Linda University School of Medicine, Loma Linda, California 92350, U.S.A
| | - Mehran Amoui
- Musculoskeletal Disease Center, Jerry L. Pettis Memorial V.A. Medical Center, Loma Linda, California 92357, U.S.A
| | - Jordan Tapia
- Musculoskeletal Disease Center, Jerry L. Pettis Memorial V.A. Medical Center, Loma Linda, California 92357, U.S.A
| | - Tyler D White
- Musculoskeletal Disease Center, Jerry L. Pettis Memorial V.A. Medical Center, Loma Linda, California 92357, U.S.A
| | - Matilda H-C Sheng
- Department of Medicine, Loma Linda University School of Medicine, Loma Linda, California 92350, U.S.A
| |
Collapse
|
13
|
Vargas VE, Landeros RV, Lopez GE, Zheng J, Magness RR. Uterine artery leptin receptors during the ovarian cycle and pregnancy regulate angiogenesis in ovine uterine artery endothelial cells†. Biol Reprod 2017; 96:866-876. [PMID: 28339937 PMCID: PMC5819836 DOI: 10.1093/biolre/iox008] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2016] [Revised: 01/31/2017] [Accepted: 02/27/2017] [Indexed: 12/12/2022] Open
Abstract
Leptin regulates body weight, reproductive functions, blood pressure, endothelial function, and fetoplacental angiogenesis. Compared to the luteal phase, the follicular phase and pregnancy are physiological states of elevated estrogen, angiogenesis, and uterine blood flow (UBF). Little is known concerning regulation of uterine artery (UA) angiogenesis by leptin and its receptors. We hypothesized that (1) ex vivo expression of leptin receptors (LEPR) in UA endothelium (UAendo) and UA vascular smooth muscle (UAvsm) is elevated in pregnant versus nonpregnant (Luteal and Follicular) sheep; (2) in vitro leptin treatments differentially modulate mitogenesis in uterine artery endothelial cells from pregnant (P-UAECs) more than in nonpregnant (NP-UAECs) ewes; and (3) LEPR are upregulated in P-UAECs versus NP-UAECs in association with leptin activation of phospho-STAT3 signaling. Local UA adaptations were evaluated using a unilateral pregnant sheep model where prebreeding uterine horn isolation (nongravid) restricted gravidity to one horn. Immunolocalization revealed LEPR in UAendo and UAvsm from pregnant and nonpregnant sheep. Contrary to our hypothesis, western analysis revealed that follicular UAendo and UAvsm LEPR were greater than luteal, nongravid, gravid, and control pregnant. Compared to pregnant groups, LEPR were elevated in renal artery endothelium of follicular and luteal sheep. Leptin treatment significantly increased mitogenesis in follicular phase NP-UAECs and P-UAECs, but not luteal phase NP-UAECs. Although UAEC expression of LEPR was similar between groups, leptin treatment only activated phospho-STAT3 in follicular NP-UAECs and P-UAECs. Thus, leptin may play an angiogenic role particularly in preparation for the increased UBF during the periovulatory period and subsequently to meet the demands of the growing fetus.
Collapse
Affiliation(s)
- Vladimir E. Vargas
- Department of Ob/Gyn, University of Wisconsin, Madison, Wisconsin, USA
- Department of Ob/Gyn, Perinatal Research Vascular Center, Morsani College of Medicine, University of South Florida, Tampa, Florida, USA
| | | | - Gladys E. Lopez
- Department of Ob/Gyn, University of Wisconsin, Madison, Wisconsin, USA
| | - Jing Zheng
- Department of Ob/Gyn, University of Wisconsin, Madison, Wisconsin, USA
| | - Ronald R. Magness
- Department of Ob/Gyn, University of Wisconsin, Madison, Wisconsin, USA
- Department of Ob/Gyn, Perinatal Research Vascular Center, Morsani College of Medicine, University of South Florida, Tampa, Florida, USA
- Department of Pediatrics, University of Wisconsin, Madison, Wisconsin, USA
- Department of Animal Sciences, University of Wisconsin, Madison, Wisconsin, USA
| |
Collapse
|
14
|
Iwaniec UT, Turner RT. Influence of body weight on bone mass, architecture and turnover. J Endocrinol 2016; 230:R115-30. [PMID: 27352896 PMCID: PMC4980254 DOI: 10.1530/joe-16-0089] [Citation(s) in RCA: 108] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/22/2016] [Accepted: 06/27/2016] [Indexed: 12/11/2022]
Abstract
Weight-dependent loading of the skeleton plays an important role in establishing and maintaining bone mass and strength. This review focuses on mechanical signaling induced by body weight as an essential mechanism for maintaining bone health. In addition, the skeletal effects of deviation from normal weight are discussed. The magnitude of mechanical strain experienced by bone during normal activities is remarkably similar among vertebrates, regardless of size, supporting the existence of a conserved regulatory mechanism, or mechanostat, that senses mechanical strain. The mechanostat functions as an adaptive mechanism to optimize bone mass and architecture based on prevailing mechanical strain. Changes in weight, due to altered mass, weightlessness (spaceflight), and hypergravity (modeled by centrifugation), induce an adaptive skeletal response. However, the precise mechanisms governing the skeletal response are incompletely understood. Furthermore, establishing whether the adaptive response maintains the mechanical competence of the skeleton has proven difficult, necessitating the development of surrogate measures of bone quality. The mechanostat is influenced by regulatory inputs to facilitate non-mechanical functions of the skeleton, such as mineral homeostasis, as well as hormones and energy/nutrient availability that support bone metabolism. Although the skeleton is very capable of adapting to changes in weight, the mechanostat has limits. At the limits, extreme deviations from normal weight and body composition are associated with impaired optimization of bone strength to prevailing body size.
Collapse
Affiliation(s)
- Urszula T Iwaniec
- Skeletal Biology LaboratorySchool of Biological and Population Health Sciences, Oregon State University, Corvallis, Oregon, USA Center for Healthy Aging ResearchOregon State University, Corvallis, Oregon, USA
| | - Russell T Turner
- Skeletal Biology LaboratorySchool of Biological and Population Health Sciences, Oregon State University, Corvallis, Oregon, USA Center for Healthy Aging ResearchOregon State University, Corvallis, Oregon, USA
| |
Collapse
|
15
|
Rendina-Ruedy E, Graef JL, Davis MR, Hembree KD, Gimble JM, Clarke SL, Lucas EA, Smith BJ. Strain differences in the attenuation of bone accrual in a young growing mouse model of insulin resistance. J Bone Miner Metab 2016; 34:380-94. [PMID: 26058493 DOI: 10.1007/s00774-015-0685-z] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/09/2014] [Accepted: 05/09/2015] [Indexed: 12/24/2022]
Abstract
Skeletal fractures are considered a chronic complication of type 2 diabetes mellitus (T2DM), but the etiology of compromised bone quality that develops over time remains uncertain. This study investigated the concurrent alterations in metabolic and skeletal changes in two mouse strains, a responsive (C57BL/6) and a relatively resistant (C3H/HeJ) strain, to high-fat diet-induced glucose intolerance. Four-week-old male C57BL/6 and C3H/HeJ mice were randomized to a control (Con = 10 % kcal fat) or high-fat (HF = 60 % kcal fat) diet for 2, 8, or 16 weeks. Metabolic changes, including blood glucose, plasma insulin and leptin, and glucose tolerance were monitored over time in conjunction with alterations in bone structure and turn over. Elevated fasting glucose occurred in both the C57BL/6 and C3H/HeJ strains on the HF diet at 2 and 8 weeks, but only in the C57BL/6 strain at 16 weeks. Both strains on the HF diet demonstrated impaired glucose tolerance at each time point. The C57BL/6 mice on the HF diet exhibited lower whole-body bone mineral density (BMD) by 8 and 16 weeks, but the C3H/HeJ strain had no evidence of bone loss until 16 weeks. Analyses of bone microarchitecture revealed that trabecular bone accrual in the distal femur metaphysis was attenuated in the C57BL/6 mice on the HF diet at 8 and 16 weeks. In contrast, the C3H/HeJ mice were protected from the deleterious effects of the HF diet on trabecular bone. Alterations in gene expression from the femur revealed that several toll-like receptor (TLR)-4 targets (Atf4, Socs3, and Tlr4) were regulated by the HF diet in the C57BL/6 strain, but not in the C3H/HeJ strain. Structural changes observed only in the C57BL/6 mice were accompanied with a decrease in osteoblastogenesis after 8 and 16 weeks on the HF diet, suggesting a TLR-4-mediated mechanism in the suppression of bone formation. Both the C57BL/6 and C3H/HeJ mice demonstrated an increase in osteoclastogenesis after 8 weeks on the HF diet; however, bone turnover was decreased in the C57BL/6 with prolonged hyperglycemia. Further investigation is needed to understand how hyperglycemia and hyperinsulinemia suppress bone turnover in the context of T2DM and the role of TLR-4 in this response.
Collapse
Affiliation(s)
- Elizabeth Rendina-Ruedy
- Department of Nutritional Sciences, HSci 420 Oklahoma State University, Stillwater, OK, 74078, USA
| | - Jennifer L Graef
- Department of Nutritional Sciences, HSci 420 Oklahoma State University, Stillwater, OK, 74078, USA
| | - McKale R Davis
- Department of Nutritional Sciences, HSci 420 Oklahoma State University, Stillwater, OK, 74078, USA
| | - Kelsey D Hembree
- Department of Nutritional Sciences, HSci 420 Oklahoma State University, Stillwater, OK, 74078, USA
| | - Jeffrey M Gimble
- Stem Cell Biology Laboratory, Pennington Biomedical Research Center, Louisiana State University, Baton Rouge, LA, USA
| | - Stephen L Clarke
- Department of Nutritional Sciences, HSci 420 Oklahoma State University, Stillwater, OK, 74078, USA
| | - Edralin A Lucas
- Department of Nutritional Sciences, HSci 420 Oklahoma State University, Stillwater, OK, 74078, USA
| | - Brenda J Smith
- Department of Nutritional Sciences, HSci 420 Oklahoma State University, Stillwater, OK, 74078, USA.
| |
Collapse
|
16
|
Poon CCW, Li RWS, Seto SW, Kong SK, Ho HP, Hoi MPM, Lee SMY, Ngai SM, Chan SW, Leung GPH, Kwan YW. In vitro vitamin K(2) and 1α,25-dihydroxyvitamin D(3) combination enhances osteoblasts anabolism of diabetic mice. Eur J Pharmacol 2015; 767:30-40. [PMID: 26452518 DOI: 10.1016/j.ejphar.2015.09.048] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2015] [Revised: 09/25/2015] [Accepted: 09/29/2015] [Indexed: 12/20/2022]
Abstract
In this study, we evaluated the anabolic effect and the underlying cellular mechanisms involved of vitamin K2 (10 nM) and 1α,25-dihydroxyvitamin D3 (1,25(OH)2D3) (10 nM), alone and in combination, on primary osteoblasts harvested from the iliac crests of C57BL/KsJ lean (+/+) and obese/diabetic (db/db) mice. A lower alkaline phosphatase (ALP) activity plus a reduced expression of bone anabolic markers and bone formation transcription factors (osteocalcin, Runx2, Dlx5, ATF4 and OSX) were consistently detected in osteoblasts of db/db mice compared to lean mice. A significantly higher calcium deposits formation in osteoblasts was observed in lean mice when compared to db/db mice. Co-administration of vitamin K2 (10 nM) and 1,25(OH)2D3 (10 nM) caused an enhancement of calcium deposits in osteoblasts in both strains of mice. Vitamins K2 and 1,25(OH)2D3 co-administration time-dependently (7, 14 and 21 days) increased the levels of bone anabolic markers and bone formation transcription factors, with a greater magnitude of increase observed in osteoblasts of db/db mice. Combined vitamins K2 plus 1,25(OH)2D3 treatment significantly enhanced migration and the re-appearance of surface microvilli and ruffles of osteoblasts of db/db mice. Thus, our results illustrate that vitamins K2 plus D3 combination could be a novel therapeutic strategy in treating diabetes-associated osteoporosis.
Collapse
Affiliation(s)
- Christina C W Poon
- School of Biomedical Sciences, Faculty of Medicine, The Chinese University of Hong Kong, Hong Kong
| | - Rachel W S Li
- School of Biomedical Sciences, Faculty of Medicine, The Chinese University of Hong Kong, Hong Kong; Department of Pharmacology and Pharmacy, Faculty of Medicine, The University of Hong Kong, Hong Kong
| | - Sai Wang Seto
- National Institute of Complementary Medicine, School of Science and Health, University of Western Sydney, Locked Bag 1797, Penrith, NSW 2751, Australia
| | - Siu Kai Kong
- School of Life Sciences, Faculty of Science, The Chinese University of Hong Kong, Hong Kong
| | - Ho Pui Ho
- Department of Electronic Engineering, Faculty of Engineering, The Chinese University of Hong Kong, Hong Kong
| | - Maggie P M Hoi
- Institute of Chinese Medical Sciences, The University of Macau, Macau, China
| | - Simon M Y Lee
- Institute of Chinese Medical Sciences, The University of Macau, Macau, China
| | - Sai Ming Ngai
- School of Life Sciences, Faculty of Science, The Chinese University of Hong Kong, Hong Kong
| | - Shun Wan Chan
- State Key Laboratory of Chinese Medicine and Molecular Pharmacology, Department of Applied Biology and Chemical Technology, The Hong Kong Polytechnic University, Hong Kong
| | - George P H Leung
- Department of Pharmacology and Pharmacy, Faculty of Medicine, The University of Hong Kong, Hong Kong.
| | - Yiu Wa Kwan
- School of Biomedical Sciences, Faculty of Medicine, The Chinese University of Hong Kong, Hong Kong.
| |
Collapse
|
17
|
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.
Collapse
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
| |
Collapse
|
18
|
A Comparative Study of the Metabolic and Skeletal Response of C57BL/6J and C57BL/6N Mice in a Diet-Induced Model of Type 2 Diabetes. J Nutr Metab 2015; 2015:758080. [PMID: 26146567 PMCID: PMC4469802 DOI: 10.1155/2015/758080] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2014] [Revised: 05/08/2015] [Accepted: 05/12/2015] [Indexed: 12/15/2022] Open
Abstract
Type 2 diabetes mellitus (T2DM) represents a complex clinical scenario of altered energy metabolism and increased fracture incidence. The C57BL/6 mouse model of diet-induced obesity has been used to study the mechanisms by which altered glucose homeostasis affects bone mass and quality, but genetic variations in substrains of C57BL/6 may have confounded data interpretation. This study investigated the long-term metabolic and skeletal consequences of two commonly used C57BL/6 substrains to a high fat (HF) diet. Male C57BL/6J, C57BL/6N, and the negative control strain, C3H/HeJ, mice were fed a control or HF diet for 24 wks. C57BL/6N mice on a HF diet demonstrated an increase in plasma insulin and blood glucose as early as 4 wk, whereas these responses were delayed in the C57BL/6J mice. The C57BL/6N mice exhibited more severe hepatic steatosis and inflammation. Only the C57BL/6N mice lost significant trabecular bone in response to the high fat diet. The C3H/HeJ mice were protected from bone loss. The data show that C57BL/6J and C57BL/6N mice differ in their metabolic and skeletal response when fed a HF diet. These substrain differences should be considered when designing experiments and are likely to have implications on data interpretation and reproducibility.
Collapse
|
19
|
Inhibition of T-Type Voltage Sensitive Calcium Channel Reduces Load-Induced OA in Mice and Suppresses the Catabolic Effect of Bone Mechanical Stress on Chondrocytes. PLoS One 2015; 10:e0127290. [PMID: 26011709 PMCID: PMC4444170 DOI: 10.1371/journal.pone.0127290] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2014] [Accepted: 04/13/2015] [Indexed: 01/23/2023] Open
Abstract
Voltage-sensitive calcium channels (VSCC) regulate cellular calcium influx, one of the earliest responses to mechanical stimulation in osteoblasts. Here, we postulate that T-type VSCCs play an essential role in bone mechanical response to load and participate in events leading to the pathology of load-induced OA. Repetitive mechanical insult was used to induce OA in Cav3.2 T-VSCC null and wild-type control mouse knees. Osteoblasts (MC3T3-E1) and chondrocytes were treated with a selective T-VSCC inhibitor and subjected to fluid shear stress to determine how blocking of T-VSCCs alters the expression profile of each cell type upon mechanical stimulation. Conditioned-media (CM) obtained from static and sheared MC3T3-E1 was used to assess the effect of osteoblast-derived factors on the chondrocyte phenotype. T-VSCC null knees exhibited significantly lower focal articular cartilage damage than age-matched controls. In vitro inhibition of T-VSCC significantly reduced the expression of both early and late mechanoresponsive genes in osteoblasts but had no effect on gene expression in chondrocytes. Furthermore, treatment of chondrocytes with CM obtained from sheared osteoblasts induced expression of markers of hypertrophy in chondrocytes and this was nearly abolished when osteoblasts were pre-treated with the T-VSCC-specific inhibitor. These results indicate that T-VSCC plays a role in signaling events associated with induction of OA and is essential to the release of osteoblast-derived factors that promote an early OA phenotype in chondrocytes. Further, these findings suggest that local inhibition of T-VSCC may serve as a therapy for blocking load-induced bone formation that results in cartilage degeneration.
Collapse
|
20
|
Stiffel V, Amoui M, Sheng MHC, Mohan S, Lau KHW. EphA4 receptor is a novel negative regulator of osteoclast activity. J Bone Miner Res 2014; 29:804-19. [PMID: 23983218 DOI: 10.1002/jbmr.2084] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/15/2013] [Revised: 08/07/2013] [Accepted: 08/20/2013] [Indexed: 11/11/2022]
Abstract
Of the ephrin (Eph) receptors, mature osteoclasts express predominantly EphA4. This study sought to determine if EphA4 has a regulatory role in osteoclasts. Treatment of RAW/C4 cells with Epha4 small interfering RNAs (siRNAs) increased average size, Ctsk mRNA expression level, and bone resorption activity of the derived osteoclast-like cells. Activation of the EphA4 signaling in osteoclast precursors with EfnA4-fc chimeric protein reduced cell size and resorption activity of the derived osteoclasts. Homozygous Epha4 null mice had substantially less trabecular bone in femur and vertebra compared to wild-type controls. The bone loss was due to a decrease in trabecular number and an increase in trabecular spacing, but not to an increase in osteoclast-lined bone surface or an increase in the number of osteoclasts on bone surface. Dynamic histomorphometry and serum biomarker analyses indicate that bone formation in Epha4 null mice was reduced slightly but not significantly. Osteoclasts of Epha4 null mice were also larger, expressed higher levels of Mmp3 and Mmp9 mRNAs, and exhibited greater bone resorption activity than wild-type osteoclasts in vitro. Deficient Epha4 expression had no effects on the total number of osteoclast formed in response to receptor activator of NF-κB ligand nor on apoptosis of osteoclasts in vitro. It also did not affect the protein-tyrosine phosphorylation status of its ligands, EfnB2, EfnA2, and EfnA4, in osteoclasts. Deficient Epha4 expression in Epha4 null osteoclasts activated the β3 -integrin signaling through reduced phosphorylation of the tyr-747 residue, which led to increased binding of the stimulatory talin and reduced binding of the inhibitory Dok1 to β3 -integrin. This in turn activated Vav3 and the bone resorption activity of osteoclasts. In conclusion, we demonstrate for the first time that EphA4 is a potent negative regulator of osteoclastic activity, mediated in part through increased Dok1 binding to β3 -integrin via an increase in EphA4-dependent tyr-747 phosphorylation.
Collapse
Affiliation(s)
- Virginia Stiffel
- Musculoskeletal Disease Center, Jerry L. Pettis Memorial VA Medical Center, Loma Linda, CA, USA
| | | | | | | | | |
Collapse
|
21
|
Stannus OP, Cao Y, Antony B, Blizzard L, Cicuttini F, Jones G, Ding C. Cross-sectional and longitudinal associations between circulating leptin and knee cartilage thickness in older adults. Ann Rheum Dis 2013; 74:82-8. [DOI: 10.1136/annrheumdis-2013-203308] [Citation(s) in RCA: 50] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
ObjectiveTo investigate cross-sectional and longitudinal associations between serum leptin levels and knee cartilage thickness in older adults.MethodsA prospective cohort of 163 randomly selected subjects (mean 63 years, range 52–78, 46% women) was studied. Knee cartilage thickness at medial tibial, lateral tibial, femoral and patellar sites was determined using T1-weighted fat-suppressed MRI. Serum leptin levels were measured by radioimmunoassay. Radiographic osteoarthritis, body fat (%), trunk fat (%), weight and height were measured, and body mass index (BMI) was calculated.ResultsCross-sectionally, serum levels of leptin were negatively associated with femoral (β: −0.013, 95% CI −0.022 to −0.003), medial tibial (β: −0.009, 95% CI −0.018 to −0.001), lateral tibial (β: −0.012, 95% CI −0.021 to −0.003) and patellar (β: −0.014, 95% CI −0.026 to −0.002) cartilage thickness after adjustment for covariates. Moreover, BMI, trunk fat and total body fat were negatively associated with cartilage thickness, and the significant associations disappeared after further adjustment for leptin. Longitudinally, both baseline leptin and change in leptin were associated with greater changes in medial tibial cartilage thickness (β: −0.004, 95% CI −0.007 to −0.001 and β: −0.009, 95% CI −0.018 to −0.001, respectively) in multivariable analyses.ConclusionsSerum levels of leptin are independently and consistently associated with reduced cartilage thickness cross-sectionally and longitudinally. In addition, the associations between adiposity measures and cartilage thickness are mediated by leptin, suggesting leptin may play a key role in cartilage thinning.
Collapse
|
22
|
Lau KHW, Baylink DJ, Zhou XD, Rodriguez D, Bonewald LF, Li Z, Ruffoni D, Müller R, Kesavan C, Sheng MHC. Osteocyte-derived insulin-like growth factor I is essential for determining bone mechanosensitivity. Am J Physiol Endocrinol Metab 2013; 305:E271-81. [PMID: 23715728 DOI: 10.1152/ajpendo.00092.2013] [Citation(s) in RCA: 65] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
This study sought to determine whether deficient Igf1 expression in osteocytes would affect loading-induced osteogenic response. Tibias of osteocyte Igf1 conditional knockout (KO) mice (generated by cross-breeding Igf1 floxed mice with Dmp1-Cre transgenic mice) and wild-type (WT) littermates were subjected to four-point bending for 2 wk. Microcomputed tomography confirmed that the size of tibias of conditional mutants was smaller. Loading with an equivalent loading strain increased periosteal woven bone and endosteal lamellar bone formation in WT mice but not in conditional KO mice. Consistent with the lack of an osteogenic response, the loading failed to upregulate expression of early mechanoresponsive genes (Igf1, Cox-2, c-fos) or osteogenic genes (Cbfa-1, and osteocalcin) in conditional KO bones. The lack of osteogenic response was not due to reduced osteocyte density or insufficient loading strain. Deficient osteocyte Igf1 expression reduced the loading-induced upregulation of expression of canonical Wnt signaling genes (Wnt10b, Lrp5, Dkk1, sFrp2). The loading also reduced (by 40%) Sost expression in WT mice, but the loading not only did not reduce but upregulated (~1.5-fold) Sost expression in conditional KO mice. Conditional disruption of Igf1 in osteocytes also abolished the loading-induced increase in the bone β-catenin protein level. These findings suggest an impaired response in the loading-induced upregulation of the Wnt signaling in conditional KO mice. In summary, conditional disruption of Igf1 in osteocytes abolished the loading-induced activation of the Wnt signaling and the corresponding osteogenic response. In conclusion, osteocyte-derived IGF-I plays a key determining role in bone mechanosensitivity.
Collapse
Affiliation(s)
- K-H William Lau
- Division of Regenerative Medicine, Department of Medicine, Loma Linda University School of Medicine, Loma Linda, CA 92350, USA
| | | | | | | | | | | | | | | | | | | |
Collapse
|
23
|
Judex S, Zhang W, Donahue LR, Ozcivici E. Genetic loci that control the loss and regain of trabecular bone during unloading and reambulation. J Bone Miner Res 2013; 28:1537-49. [PMID: 23401066 DOI: 10.1002/jbmr.1883] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/18/2012] [Revised: 01/15/2013] [Accepted: 01/23/2013] [Indexed: 12/18/2022]
Abstract
Changes in trabecular morphology during unloading and reloading are marked by large variations between individuals, implying that there is a strong genetic influence on the magnitude of the response. Here, we subjected more than 350 second-generation (BALBxC3H) 4-month-old adult female mice to 3 weeks of hindlimb unloading followed by 3 weeks of reambulation to identify the quantitative trait loci (QTLs) that define an individual's propensity to either lose trabecular bone when weight bearing is removed or to gain trabecular bone when weight bearing is reintroduced. Longitudinal in vivo micro-computed tomography (µCT) scans demonstrated that individual mice lost between 15% and 71% in trabecular bone volume fraction (BV/TV) in the distal femur during unloading (average: -43%). Changes in trabecular BV/TV during the 3-week reambulation period ranged from a continuation of bone loss (-18%) to large additions (56%) of tissue (average: +10%). During unloading, six QTLs accounted for 21% of the total variability in changes in BV/TV whereas one QTL accounted for 6% of the variability in changes in BV/TV during reambulation. QTLs were also identified for changes in trabecular architecture. Most of the QTLs defining morphologic changes during unloading or reambulation did not overlap with those QTLs identified at baseline, suggesting that these QTLs harbor genes that are specific for sensing changes in the levels of weight bearing. The lack of overlap in QTLs between unloading and reambulation also emphasizes that the genes modulating the trabecular response to unloading are distinct from those regulating tissue recovery during reloading. The identified QTLs contain the regulatory genes underlying the strong genetic regulation of trabecular bone's sensitivity to weight bearing and may help to identify individuals that are most susceptible to unloading-induced bone loss and/or the least capable of recovering.
Collapse
Affiliation(s)
- Stefan Judex
- Department of Biomedical Engineering, Stony Brook University, Stony Brook, NY, USA
| | | | | | | |
Collapse
|
24
|
Sawicka-Żukowska M, Krawczuk-Rybak M, Muszynska-Roslan K, Panasiuk A, Latoch E, Konstantynowicz J. Does Q223R Polymorphism of Leptin Receptor Influence on Anthropometric Parameters and Bone Density in Childhood Cancer Survivors? Int J Endocrinol 2013; 2013:805312. [PMID: 24319457 PMCID: PMC3834979 DOI: 10.1155/2013/805312] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/17/2013] [Revised: 07/07/2013] [Accepted: 07/08/2013] [Indexed: 12/29/2022] Open
Abstract
Childhood cancer survivors are in augmented risk for developing obesity. For many factors leptin and leptin receptor gene polymorphism play an important role in the development and metabolism not only of fat, but also, bone tissue. The aim of the analysis was to find the relationships between Q223R, leptin levels, and anthropometric parameters. Patients and Methods. In the study 74 cancer survivors participated (ALL n = 64, lymphomas n = 10), and the control group consisted of 51 healthy peers. Leptin blood concentration was determined by ELISA method. To estimate leptin receptor gene polymorphism, RFLP method was used. Bone mineral density (BMD) and content (BMC), fat, and lean tissue measurements were obtained by DXA. Results. We found no correlations between serum leptin concentrations and anthropometric parameters nor BMD. Serum leptin concentrations were significantly lower in the group of cancer survivors compared to controls; however, in those overweight from examined group we found leptin levels higher than those in nonoverweight. Genotype Q223R was not associated with higher leptin levels, BMI, BMD, body fat or lean tissue. Conclusion. To our knowledge, this is the first report describing the relationship between BMD and Q223R polymorphism in childhood cancer survivors. Further analysis, based on a larger group of patients, is needed to confirm these findings.
Collapse
Affiliation(s)
- Malgorzata Sawicka-Żukowska
- Department of Pediatric Oncology and Hematology, Medical University of Bialystok, 15-274 Bialystok, Poland
- *Malgorzata Sawicka-Żukowska:
| | - Maryna Krawczuk-Rybak
- Department of Pediatric Oncology and Hematology, Medical University of Bialystok, 15-274 Bialystok, Poland
| | - Katarzyna Muszynska-Roslan
- Department of Pediatric Oncology and Hematology, Medical University of Bialystok, 15-274 Bialystok, Poland
| | - Anna Panasiuk
- Department of Pediatric Oncology and Hematology, Medical University of Bialystok, 15-274 Bialystok, Poland
| | - Eryk Latoch
- Department of Pediatric Oncology and Hematology, Medical University of Bialystok, 15-274 Bialystok, Poland
| | - Jerzy Konstantynowicz
- Department of Pediatric Oncology and Hematology, Medical University of Bialystok, 15-274 Bialystok, Poland
| |
Collapse
|
25
|
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.
Collapse
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
| |
Collapse
|
26
|
New insights into adhesion signaling in bone formation. INTERNATIONAL REVIEW OF CELL AND MOLECULAR BIOLOGY 2013; 305:1-68. [PMID: 23890379 DOI: 10.1016/b978-0-12-407695-2.00001-9] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Mineralized tissues that are protective scaffolds in the most primitive species have evolved and acquired more specific functions in modern animals. These are as diverse as support in locomotion, ion homeostasis, and precise hormonal regulation. Bone formation is tightly controlled by a balance between anabolism, in which osteoblasts are the main players, and catabolism mediated by the osteoclasts. The bone matrix is deposited in a cyclic fashion during homeostasis and integrates several environmental cues. These include diffusible elements that would include estrogen or growth factors and physicochemical parameters such as bone matrix composition, stiffness, and mechanical stress. Therefore, the microenvironment is of paramount importance for controlling this delicate equilibrium. Here, we provide an overview of the most recent data highlighting the role of cell-adhesion molecules during bone formation. Due to the very large scope of the topic, we focus mainly on the role of the integrin receptor family during osteogenesis. Bone phenotypes of some deficient mice as well as diseases of human bones involving cell adhesion during this process are discussed in the context of bone physiology.
Collapse
|
27
|
Jeong J, Kim Y, Kyung Seong J, Lee KJ. Comprehensive identification of novel post-translational modifications in cellular peroxiredoxin 6. Proteomics 2012; 12:1452-62. [PMID: 22589192 DOI: 10.1002/pmic.201100558] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Peroxiredoxin 6 (PRDX6), a 1-Cys peroxiredoxin, is a bifunctional enzyme acting both as a glutathione peroxidase and a phospholipase A2. However, the underlying mechanisms and their regulation mechanisms are not well understood. Because post-translational modifications (PTMs) have been shown to play important roles in the function of many proteins, we undertook, in this study, to identify the PTMs in PRDX6 utilizing proteomic tools including nanoUPLC-ESI-q-TOF MS/MS employing selectively excluded mass screening analysis (SEMSA) in conjunction with MOD(i) and MODmap algorithm. We chose PRDX6 obtained from liver tissues from two inbred mouse strains, C57BL/6J and C3H/HeJ, which vary in their susceptibility to high-fat diet-induced obesity and atherosclerosis, and a B16F10 melanoma cell line for this study. When PRDX6 protein samples were separated on 2D-PAGE based on pI, several PRDX6 spots appeared. They were purified and the low abundant PTMs in each PRDX6 spot were analyzed. Unexpected mass shifts (Δm = -34, +25, +64, +87, +103, +134, +150, +284 Da) observed at active site cysteine residue (Cys47) were quantified using precursor ion intensities. Mass differences of -34, +25, and +64 Da are presumed to reflect the conversion of cysteine to dehydroalanine, cyano, and Cys-SO(2) -SH, respectively. We also detected acrylamide adducts of sulfenic and sulfinic acids (+87 and +103 Da) as well as unknown modifications (+134, +150, +284 Da). Comprehensive analysis of these PTMs revealed that the PRDX6 exists as a heterogeneous mixture of molecules containing a multitude of PTMs. Several of these modifications occur at cysteine residue in the enzyme active site. Other modifications observed, in PRDX6 from mouse liver tissues included, among others, mono- and dioxidation at Trp and Met, acetylation at Lys, and deamidation at Asn and Gln. Comprehensive identification of the diverse PTMs occurring in this bifunctional PRDX6 enzyme should help understand how PRDX6 plays key roles in oxidative stresses.
Collapse
Affiliation(s)
- Jaeho Jeong
- The Center for Cell Signaling & Drug Discovery Research, College of Pharmacy, Division of Life & Pharmaceutical Sciences, Department of Bioinspired Science, Ewha Womans University, Seoul, Korea
| | | | | | | |
Collapse
|
28
|
Tanaka KI, Matsumoto E, Higashimaki Y, Katagiri T, Sugimoto T, Seino S, Kaji H. Role of osteoglycin in the linkage between muscle and bone. J Biol Chem 2012; 287:11616-28. [PMID: 22351757 DOI: 10.1074/jbc.m111.292193] [Citation(s) in RCA: 87] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
The interaction between muscle tissues and bone metabolism is incompletely understood. We hypothesized that there might be some humoral factors that are produced in muscle tissues and exhibit bone anabolic activity. We, therefore, performed comparative DNA microarray analysis between mouse myoblastic C2C12 cells transfected with either stable empty vector or ALK2 (R206H), the mutation that constitutively activates the bone morphogenetic protein (BMP) receptor, to search for muscle-derived bone anabolic factors. Twenty-five genes whose expression was decreased to <1/4, were identified; these included osteoglycin (OGN). Stable overexpression of OGN significantly decreased the levels of Runx2 and Osterix mRNA compared with those in cells transfected with vector alone in MC3T3-E1 cells. On the other hand, it significantly enhanced the levels of alkaline phosphatase (ALP), type I collagen (Col1), and osteocalcin (OCN) mRNA as well as β-catenin and mineralization. A reduction in endogenous OGN level showed the opposite effects to those of OGN overexpression in MC3T3-E1 and mouse calvarial osteoblastic cells. Transient OGN overexpression significantly suppressed the levels of Runx2, Osterix, ALP, Col1, and OCN mRNA induced by BMP-2 in C2C12 cells. The conditioned medium from OGN-overexpressed and OGN-suppressed myoblastic cells enhanced and decreased, respectively, the levels of ALP, Col1, and β-catenin in MC3T3-E1 cells. Moreover, OGN increased Smad3/4-responsive transcriptional activity as well as Col1 mRNA levels independently of endogenous TGF-β in these cells. In conclusion, this study suggests that OGN may be a crucial humoral bone anabolic factor that is produced by muscle tissues.
Collapse
Affiliation(s)
- Ken-ichiro Tanaka
- Division of Diabetes and Endocrinology, Department of Internal Medicine, Kobe University Graduate School of Medicine, Kobe 650-0017, Japan
| | | | | | | | | | | | | |
Collapse
|
29
|
Wu RW, Lin TP, Ko JY, Yeh DW, Chen MW, Ke HC, Wu SL, Wang FS. Cannabinoid receptor 1 regulates ERK and GSK-3β-dependent glucocorticoid inhibition of osteoblast differentiation in murine MC3T3-E1 cells. Bone 2011; 49:1255-63. [PMID: 21914493 DOI: 10.1016/j.bone.2011.08.022] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/07/2011] [Revised: 08/19/2011] [Accepted: 08/20/2011] [Indexed: 11/29/2022]
Abstract
Supraphysiological glucocorticoid administration accelerates loss of survival and differentiation in osteoblastic cells, thereby increasing the risks of osteopenic or osteonecrotic disorders. Neuroendocrine component type 1 cannabinoid receptor (CB1) is found to regulate bone mass. This study characterized the biological role of CB1 in glucocorticoid-induced suppression of osteoblast differentiation. Murine MC3T3-E1 osteoblasts were incubated under osteogenic conditions in the presence or absence of 1 μM glucocorticoid, RNA interference, CB1 antagonist AM251, and agonist WIN55212-2. Cell survival was detected by formazan synthesis and TUNEL staining. Osteoblast differentiation was quantified by mineralized matrix accumulation and expression of the osteogenic factors Runx2 and osteocalcin. Expression of signaling molecules was assessed by immunoblotting. Glucocorticoid increased CB1 expression in association with decreased osteocalcin expression and mineralized nodule deposition. CB1 RNA interference and AM251 attenuated the deleterious actions of glucocorticoid treatment on survival and osteogenic activities, whereas activating CB1 by WIN55212-2 impaired osteoblast differentiation. CB1 signaling regulated JNK, ERK, GSK-3β, and Akt activation as well as Runx2 and IGF-I expression. Inhibition of GSK-3β by the kinase-inactive GSK-3β mutant or activation of ERK by the active MEK-1 mutant abrogated glucocorticoid-induced inhibition of osteoblast differentiation. Glucocorticoid-induced CB1 expression occurred via glucocorticoid receptor-dependent transcriptional and translational regulation. Gain of Runx2 function and loss of MKP-1 action attenuated glucocorticoid-induced enhancement of CB1 expression. Taken together, CB1 regulation of ERK and GSK-3β-dependent pathways participates in glucocorticoid inhibition of Runx2 signaling and osteoblast differentiation. Runx2 reciprocally regulates glucocorticoid-induced promotion of CB1 signaling. Our findings provide new insights into the role of the neuroendocrine component CB1 in glucocorticoid-induced osteoblast dysfunction.
Collapse
Affiliation(s)
- Re-Wen Wu
- Department of Orthopedic Surgery, Koahsiung Chang Gung Memorial Hospital, Kaohsiung, Taiwan
| | | | | | | | | | | | | | | |
Collapse
|
30
|
Price JS, Sugiyama T, Galea GL, Meakin LB, Sunters A, Lanyon LE. Role of endocrine and paracrine factors in the adaptation of bone to mechanical loading. Curr Osteoporos Rep 2011; 9:76-82. [PMID: 21384138 DOI: 10.1007/s11914-011-0050-7] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
There appears to be no unique mechanically sensitive pathway by which changes in bone loading regulate bone mass and architecture to ensure adequate structural strength. Rather, strain-derived changes in bone cells activate a number of nonspecific strain-sensitive pathways (including calcium fluxes, prostanoids, nitric oxide, extracellular signal-regulated kinase, and sclerostin), the activities of which are modified by a number of factors (including estrogen receptors) for which this contribution is subsidiary to other purposes. The strain-sensitive pathways modified by these factors interact with a number of other pathways, some of which appear to have specific osteoregulatory potential (eg, the parathyroid hormone pathway), whereas others such as the Wnt pathway appear to be associated primarily with the response mechanisms of proliferation, differentiation, and apoptosis. The outcome of these multiple interactions are stimuli for local bone formation, resorption, or maintenance of the status quo, to maintain existing bone architecture or adapt it to a new mechanical regimen.
Collapse
Affiliation(s)
- Joanna S Price
- School of Veterinary Sciences, University of Bristol, Langford House, Langford, Bristol BS40 5DU, UK.
| | | | | | | | | | | |
Collapse
|