51
|
Nordberg RC, Mellor LF, Krause AR, Donahue HJ, Loboa EG. LRP receptors in chondrocytes are modulated by simulated microgravity and cyclic hydrostatic pressure. PLoS One 2019; 14:e0223245. [PMID: 31584963 PMCID: PMC6777824 DOI: 10.1371/journal.pone.0223245] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2019] [Accepted: 09/17/2019] [Indexed: 01/16/2023] Open
Abstract
Mechanical loading is essential for the maintenance of musculoskeletal homeostasis. Cartilage has been demonstrated to be highly mechanoresponsive, but the mechanisms by which chondrocytes respond to mechanical stimuli are not clearly understood. The goal of the study was to determine how LRP4, LRP5, and LRP6 within canonical Wnt-signaling are regulated in simulated microgravity and cyclic hydrostatic pressure, and to investigate the potential role of LRP 4/5/6 in cartilage degeneration. Rat chondrosacroma cell (RCS) pellets were stimulated using either cyclic hydrostatic pressure (1Hz, 7.5 MPa, 4hr/day) or simulated microgravity in a rotating wall vessel (RWV) bioreactor (11RPM, 24hr/day). LRP4/5/6 mRNA expression was assessed by RT-qPCR and LRP5 protein expression was determined by fluorescent immunostaining. To further evaluate our in vitro findings in vivo, mice were subjected to hindlimb suspension for 14 days and the femoral heads stained for LRP5 expression. We found that, in vitro, LRP4/5/6 mRNA expression is modulated in a time-dependent manner by mechanical stimulation. Additionally, LRP5 protein expression is upregulated in response to both simulated microgravity and cyclic hydrostatic pressure. LRP5 is also upregulated in vivo in the articular cartilage of hindlimb suspended mice. This is the first study to examine how LRP4/5/6, critical receptors within musculoskeletal biology, respond to mechanical stimulation. Further elucidation of this mechanism could provide significant clinical benefit for the identification of pharmaceutical targets for the maintenance of cartilage health.
Collapse
Affiliation(s)
- Rachel C. Nordberg
- College of Engineering, University of Missouri, Columbia, Missouri, United States of America
| | | | - Andrew R. Krause
- Sport Health and Physical Education, Vancouver Island University, Nanaimo, British Columbia, Canada
| | - Henry J. Donahue
- Division of Musculoskeletal Sciences, Department of Orthopaedics and Rehabilitation, Penn State College of Medicine, Hershey, Pennsylvania, United States of America
- Department of Biomedical Engineering, Virginia Commonwealth University, Richmond, Virginia, United States of America
| | - Elizabeth G. Loboa
- College of Engineering, University of Missouri, Columbia, Missouri, United States of America
- * E-mail:
| |
Collapse
|
52
|
Bullock WA, Hoggatt A, Horan DJ, Lewis K, Yokota H, Hann S, Warman ML, Sebastian A, Loots GG, Pavalko FM, Robling AG. Expression of a Degradation-Resistant β-Catenin Mutant in Osteocytes Protects the Skeleton From Mechanodeprivation-Induced Bone Wasting. J Bone Miner Res 2019; 34:1964-1975. [PMID: 31173667 PMCID: PMC6813861 DOI: 10.1002/jbmr.3812] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/02/2019] [Revised: 05/02/2019] [Accepted: 05/25/2019] [Indexed: 12/28/2022]
Abstract
Mechanical stimulation is a key regulator of bone mass, maintenance, and turnover. Wnt signaling is a key regulator of mechanotransduction in bone, but the role of β-catenin-an intracellular signaling node in the canonical Wnt pathway-in disuse mechanotransduction is not defined. Using the β-catenin exon 3 flox (constitutively active [CA]) mouse model, in conjunction with a tamoxifen-inducible, osteocyte-selective Cre driver, we evaluated the effects of degradation-resistant β-catenin on bone properties during disuse. We hypothesized that if β-catenin plays an important role in Wnt-mediated osteoprotection, then artificial stabilization of β-catenin in osteocytes would protect the limbs from disuse-induced bone wasting. Two disuse models were tested: tail suspension, which models fluid shift, and botulinum-toxin (botox)-induced muscle paralysis, which models loss of muscle force. Tail suspension was associated with a significant loss of tibial bone mass and density, reduced architectural properties, and decreased bone formation indices in uninduced (control) mice, as assessed by dual-energy X-ray absorptiometry (DXA), micro-computed tomography (µCT), and histomorphometry. Activation of the βcatCA allele in tail-suspended mice resulted in little to no change in those properties; ie, these mice were protected from bone loss. Similar protective effects were observed among botox-treated mice when the βcatCA was activated. RNAseq analysis of altered gene regulation in tail-suspended mice yielded 35 genes, including Wnt11, Gli1, Nell1, Gdf5, and Pgf, which were significantly differentially regulated between tail-suspended β-catenin stabilized mice and tail-suspended nonstabilized mice. Our findings indicate that selectively targeting/blocking of β-catenin degradation in bone cells could have therapeutic implications in mechanically induced bone disease. © 2019 American Society for Bone and Mineral Research.
Collapse
Affiliation(s)
- Whitney A. Bullock
- Department of Anatomy & Cell Biology, Indiana University School of Medicine, Indianapolis, IN, USA
| | - April Hoggatt
- Department of Anatomy & Cell Biology, Indiana University School of Medicine, Indianapolis, IN, USA
| | - Daniel J. Horan
- Department of Anatomy & Cell Biology, Indiana University School of Medicine, Indianapolis, IN, USA
| | - Karl Lewis
- Department of Anatomy & Cell Biology, Indiana University School of Medicine, Indianapolis, IN, USA
| | - Hiroki Yokota
- Department of Biomedical Engineering, Indiana University-Purdue University at Indianapolis, Indianapolis, IN, USA
| | - Steven Hann
- Department of Orthopaedic Surgery, Boston Children’s Hospital, Boston, MA, USA
| | - Matthew L. Warman
- Department of Orthopaedic Surgery, Boston Children’s Hospital, Boston, MA, USA
| | - Aimy Sebastian
- Biology and Biotechnology Division, Lawrence Livermore National Laboratory, Livermore, CA, USA
| | - Gabriela G. Loots
- Biology and Biotechnology Division, Lawrence Livermore National Laboratory, Livermore, CA, USA
| | - Fredrick M. Pavalko
- Department of Integrative and Cellular Physiology, Indiana University School of Medicine, Indianapolis, IN, USA
- Richard L. Roudebush VA Medical Center, Indianapolis, IN, USA
| | - Alexander G. Robling
- Department of Anatomy & Cell Biology, Indiana University School of Medicine, Indianapolis, IN, USA
- Department of Biomedical Engineering, Indiana University-Purdue University at Indianapolis, Indianapolis, IN, USA
- Richard L. Roudebush VA Medical Center, Indianapolis, IN, USA
- Indiana Center for Musculoskeletal Health, Indianapolis, IN, USA
| |
Collapse
|
53
|
Abstract
PURPOSE OF REVIEW The goal of this paper is to review state-of-the-art transcriptome profiling methods and their recent applications in the field of skeletal biology. RECENT FINDINGS Next-generation sequencing of mRNA (RNA-seq) methods have been established and routinely used in skeletal biology research. RNA-seq has led to the identification of novel genes and transcription factors involved in skeletal development and disease, through its application in small and large animal models, as well as human tissue and cells. With the availability of advanced techniques such as single-cell RNA-seq, novel cell types in skeletal tissues are being identified. As the sequencing technologies are rapidly evolving, the exciting discoveries supported by transcriptomics will continue to emerge and improve our understanding of the biology of the skeleton.
Collapse
Affiliation(s)
- Ugur Ayturk
- Musculoskeletal Integrity Program, Hospital for Special Surgery, 515 East 71st St. Suite 403, New York, NY, 10021, USA.
| |
Collapse
|
54
|
Bullock WA, Pavalko FM, Robling AG. Osteocytes and mechanical loading: The Wnt connection. Orthod Craniofac Res 2019; 22 Suppl 1:175-179. [DOI: 10.1111/ocr.12282] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2019] [Accepted: 01/04/2019] [Indexed: 02/03/2023]
Affiliation(s)
- Whitney A. Bullock
- Department of Anatomy & Cell BiologyIndiana University School of Medicine Indianapolis Indiana
| | - Frederick M. Pavalko
- Department of Anatomy & Cell BiologyIndiana University School of Medicine Indianapolis Indiana
| | - Alexander G. Robling
- Department of Anatomy & Cell BiologyIndiana University School of Medicine Indianapolis Indiana
| |
Collapse
|
55
|
Brommage R, Powell DR, Vogel P. Predicting human disease mutations and identifying drug targets from mouse gene knockout phenotyping campaigns. Dis Model Mech 2019; 12:dmm038224. [PMID: 31064765 PMCID: PMC6550044 DOI: 10.1242/dmm.038224] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
Two large-scale mouse gene knockout phenotyping campaigns have provided extensive data on the functions of thousands of mammalian genes. The ongoing International Mouse Phenotyping Consortium (IMPC), with the goal of examining all ∼20,000 mouse genes, has examined 5115 genes since 2011, and phenotypic data from several analyses are available on the IMPC website (www.mousephenotype.org). Mutant mice having at least one human genetic disease-associated phenotype are available for 185 IMPC genes. Lexicon Pharmaceuticals' Genome5000™ campaign performed similar analyses between 2000 and the end of 2008 focusing on the druggable genome, including enzymes, receptors, transporters, channels and secreted proteins. Mutants (4654 genes, with 3762 viable adult homozygous lines) with therapeutically interesting phenotypes were studied extensively. Importantly, phenotypes for 29 Lexicon mouse gene knockouts were published prior to observations of similar phenotypes resulting from homologous mutations in human genetic disorders. Knockout mouse phenotypes for an additional 30 genes mimicked previously published human genetic disorders. Several of these models have helped develop effective treatments for human diseases. For example, studying Tph1 knockout mice (lacking peripheral serotonin) aided the development of telotristat ethyl, an approved treatment for carcinoid syndrome. Sglt1 (also known as Slc5a1) and Sglt2 (also known as Slc5a2) knockout mice were employed to develop sotagliflozin, a dual SGLT1/SGLT2 inhibitor having success in clinical trials for diabetes. Clinical trials evaluating inhibitors of AAK1 (neuropathic pain) and SGLT1 (diabetes) are underway. The research community can take advantage of these unbiased analyses of gene function in mice, including the minimally studied 'ignorome' genes.
Collapse
Affiliation(s)
- Robert Brommage
- Department of Metabolism Research, Lexicon Pharmaceuticals, 8800 Technology Forest Place, The Woodlands, TX 77381, USA
| | - David R Powell
- Department of Metabolism Research, Lexicon Pharmaceuticals, 8800 Technology Forest Place, The Woodlands, TX 77381, USA
| | - Peter Vogel
- St. Jude Children's Research Hospital, Pathology, MS 250, Room C5036A, 262 Danny Thomas Place, Memphis, TN 38105, USA
| |
Collapse
|
56
|
Kang KS, Hong JM, Horan DJ, Lim KE, Bullock WA, Bruzzaniti A, Hann S, Warman ML, Robling AG. Induction of Lrp5 HBM-causing mutations in Cathepsin-K expressing cells alters bone metabolism. Bone 2019; 120:166-175. [PMID: 30409757 PMCID: PMC6360125 DOI: 10.1016/j.bone.2018.10.007] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/10/2018] [Revised: 09/06/2018] [Accepted: 10/08/2018] [Indexed: 12/19/2022]
Abstract
High-bone-mass (HBM)-causing missense mutations in the low density lipoprotein receptor-related protein-5 (Lrp5) are associated with increased osteoanabolic action and protection from disuse- and ovariectomy-induced osteopenia. These mutations (e.g., A214V and G171V) confer resistance to endogenous secreted Lrp5/6 inhibitors, such as sclerostin (SOST) and Dickkopf homolog-1 (DKK1). Cells in the osteoblast lineage are responsive to canonical Wnt stimulation, but recent work has indicated that osteoclasts exhibit both indirect and direct responsiveness to canonical Wnt. Whether Lrp5-HBM receptors, expressed in osteoclasts, might alter osteoclast differentiation, activity, and consequent net bone balance in the skeleton, is not known. To address this, we bred mice harboring heterozygous Lrp5 HBM-causing conditional knock-in alleles to Ctsk-Cre transgenic mice and studied the phenotype using DXA, μCT, histomorphometry, serum assays, and primary cell culture. Mice with HBM alleles induced in Ctsk-expressing cells (TG) exhibited higher bone mass and architectural properties compared to non-transgenic (NTG) counterparts. In vivo and in vitro measurements of osteoclast activity, population density, and differentiation yielded significant reductions in osteoclast-related parameters in female but not male TG mice. Droplet digital PCR performed on osteocyte enriched cortical bone tubes from TG and NTG mice revealed that ~8-17% of the osteocyte population (depending on sex) underwent recombination of the conditional Lrp5 allele in the presence of Ctsk-Cre. Further, bone formation parameters in the midshaft femur cortex show a small but significant increase in anabolic action on the endocortical but not periosteal surface. These findings suggest that Wnt/Lrp5 signaling in osteoclasts affects osteoclastogenesis and activity in female mice, but also that some of the changes in bone mass in TG mice might be due to Cre expression in the osteocyte population.
Collapse
Affiliation(s)
- Kyung Shin Kang
- Department of Anatomy & Cell Biology, Indiana University School of Medicine, Indianapolis, IN, USA; Richard L. Roudebush VA Medical Center, Indianapolis, IN, USA; School of Physical Science & Engineering, Anderson University, Anderson, IN, USA
| | - Jung Min Hong
- Department of Biomedical & Applied Sciences, Indiana University School of Dentistry, Indianapolis, IN, USA
| | - Daniel J Horan
- Department of Anatomy & Cell Biology, Indiana University School of Medicine, Indianapolis, IN, USA
| | - Kyung-Eun Lim
- Department of Anatomy & Cell Biology, Indiana University School of Medicine, Indianapolis, IN, USA
| | - Whitney A Bullock
- Department of Anatomy & Cell Biology, Indiana University School of Medicine, Indianapolis, IN, USA
| | - Angela Bruzzaniti
- Department of Biomedical & Applied Sciences, Indiana University School of Dentistry, Indianapolis, IN, USA
| | - Steven Hann
- Department of Orthopaedic Surgery, Boston Children's Hospital, Boston, MA, USA
| | - Matthew L Warman
- Department of Orthopaedic Surgery, Boston Children's Hospital, Boston, MA, USA; Howard Hughes Medical Institute, Department of Genetics, Harvard Medical School, Boston, MA, USA
| | - Alexander G Robling
- Department of Anatomy & Cell Biology, Indiana University School of Medicine, Indianapolis, IN, USA; Richard L. Roudebush VA Medical Center, Indianapolis, IN, USA; Department of Biomedical Engineering, Indiana University-Purdue University at Indianapolis, Indianapolis, IN, USA.
| |
Collapse
|
57
|
Abstract
PURPOSE OF REVIEW We reviewed recent literature on oxygen sensing in osteogenic cells and its contribution to development of a skeletal phenotype, the coupling of osteogenesis with angiogenesis and integration of hypoxia into canonical Wnt signaling, and opportunities to manipulate oxygen sensing to promote skeletal repair. RECENT FINDINGS Oxygen sensing in osteocytes can confer a high bone mass phenotype in murine models; common and unique targets of HIF-1α and HIF-2α and lineage-specific deletion of oxygen sensing machinery suggest differentia utilization and requirement of HIF-α proteins in the differentiation from mesenchymal stem cell to osteoblast to osteocyte; oxygen-dependent but HIF-α-independent signaling may contribute to observed skeletal phenotypes. Manipulating oxygen sensing machinery in osteogenic cells influences skeletal phenotype through angiogenesis-dependent and angiogenesis-independent pathways and involves HIF-1α, HIF-2α, or both proteins. Clinically, an FDA-approved iron chelator promotes angiogenesis and osteogenesis, thereby enhancing the rate of fracture repair.
Collapse
Affiliation(s)
- Clare E Yellowley
- Department of Anatomy, Physiology, and Cell Biology, School of Veterinary Medicine, University of California, Davis, 1089 Veterinary Medicine Drive, Davis, CA, 95616, USA
| | - Damian C Genetos
- Department of Anatomy, Physiology, and Cell Biology, School of Veterinary Medicine, University of California, Davis, 1089 Veterinary Medicine Drive, Davis, CA, 95616, USA.
| |
Collapse
|
58
|
Sost Haploinsufficiency Provokes Peracute Lethal Cardiac Tamponade without Rescuing the Osteopenia in a Mouse Model of Excess Glucocorticoids. THE AMERICAN JOURNAL OF PATHOLOGY 2019; 189:753-761. [PMID: 30664862 PMCID: PMC6445804 DOI: 10.1016/j.ajpath.2018.12.007] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/29/2018] [Revised: 11/21/2018] [Accepted: 12/07/2018] [Indexed: 11/23/2022]
Abstract
Glucocorticoid-induced secondary osteoporosis is the most predictable side effect of this anti-inflammatory. One of the main mechanisms by which glucocorticoids achieve such deleterious outcome in bone is by antagonizing Wnt/β-catenin signaling. Sclerostin, encoded by Sost gene, is the main negative regulator of the proformative and antiresorptive role of the Wnt signaling pathway in the skeleton. It was hypothesized that the partial inactivation of sclerostin function by genetic manipulation will rescue the osteopenia induced by high endogenous glucocorticoid levels. Sost-deficient mice were crossed with an established mouse model of excess glucocorticoids, and the effects on bone mass and structure were evaluated. Sost haploinsufficiency did not rescue the low bone mass induced by high glucocorticoids. Intriguingly, the critical manifestation of Sost deficiency combined with glucocorticoid excess was sporadic, sudden, unprovoked, and nonconvulsive death. Detailed histopathologic analysis in a wide range of tissues identified peracute hemopericardium and cardiac tamponade to be the cause. These preclinical studies reveal outcomes with direct relevance to ongoing clinical trials that explore the use of antisclerostin antibodies as a treatment for osteoporosis. They particularly highlight a potential for increased cardiovascular risk and may inform improved stratification of patients who might otherwise benefit from antisclerostin antibody treatment.
Collapse
|
59
|
|
60
|
Norwitz NG, Mota AS, Misra M, Ackerman KE. LRP5, Bone Density, and Mechanical Stress: A Case Report and Literature Review. Front Endocrinol (Lausanne) 2019; 10:184. [PMID: 30972028 PMCID: PMC6443714 DOI: 10.3389/fendo.2019.00184] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/04/2019] [Accepted: 03/06/2019] [Indexed: 11/17/2022] Open
Abstract
The Wnt-β-catenin pathway receptor, low-density lipoprotein receptor-related protein 5 (LRP5), is a known regulator of bone mineral density. It has been hypothesized that specific human polymorphisms in LRP5 impact bone density, in part, by altering the anabolic response of bone to mechanical loading. Although experiments in animal models support this hypothesis, there is limited evidence that LRP5 polymorphisms can alter the anabolic response of bone to mechanical loading in humans. Herein, we report a young male who harbors a rare LRP5 missense mutation (A745V) and who provides potential proof of principle for this mechanotransduction hypothesis for low bone density. The subject had no history of fractures until age 18, a year into a career in competitive distance running. As he continued to run over the following 2 years, his mileage threshold to fracture steadily and rapidly decreased until he was diagnosed with severe osteoporosis (lumbar spine BMD Z-score of -3.2). By contextualizing this case within the existing LRP5 and mechanical stress literature, we speculate that this represents the first documented case of an individual in whom a genetic mutation altered the anabolic response of bone to mechanical stress in a manner sufficient to contribute to osteoporosis.
Collapse
Affiliation(s)
- Nicholas G. Norwitz
- Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, United Kingdom
- Harvard Medical School, Boston, MA, United States
- *Correspondence: Nicholas G. Norwitz
| | - Adrian Soto Mota
- Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, United Kingdom
| | - Madhusmita Misra
- Harvard Medical School, Boston, MA, United States
- Division of Pediatric Endocrinology, Massachusetts General Hospital, Boston, MA, United States
- Neuroendocrine Unit, Massachusetts General Hospital, Boston, MA, United States
| | - Kathryn E. Ackerman
- Harvard Medical School, Boston, MA, United States
- Neuroendocrine Unit, Massachusetts General Hospital, Boston, MA, United States
- Divisions of Sports Medicine and Endocrinology, Boston Children's Hospital, Boston, MA, United States
| |
Collapse
|
61
|
Brommage R, Ohlsson C. High Fidelity of Mouse Models Mimicking Human Genetic Skeletal Disorders. Front Endocrinol (Lausanne) 2019; 10:934. [PMID: 32117046 PMCID: PMC7010808 DOI: 10.3389/fendo.2019.00934] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/02/2019] [Accepted: 12/23/2019] [Indexed: 12/24/2022] Open
Abstract
UNLABELLED The 2019 International Skeletal Dysplasia Society nosology update lists 441 genes for which mutations result in rare human skeletal disorders. These genes code for enzymes (33%), scaffolding proteins (18%), signal transduction proteins (16%), transcription factors (14%), cilia proteins (8%), extracellular matrix proteins (5%), and membrane transporters (4%). Skeletal disorders include aggrecanopathies, channelopathies, ciliopathies, cohesinopathies, laminopathies, linkeropathies, lysosomal storage diseases, protein-folding and RNA splicing defects, and ribosomopathies. With the goal of evaluating the ability of mouse models to mimic these human genetic skeletal disorders, a PubMed literature search identified 260 genes for which mutant mice were examined for skeletal phenotypes. These mouse models included spontaneous and ENU-induced mutants, global and conditional gene knockouts, and transgenic mice with gene over-expression or specific base-pair substitutions. The human X-linked gene ARSE and small nuclear RNA U4ATAC, a component of the minor spliceosome, do not have mouse homologs. Mouse skeletal phenotypes mimicking human skeletal disorders were observed in 249 of the 260 genes (96%) for which comparisons are possible. A supplemental table in spreadsheet format provides PubMed weblinks to representative publications of mutant mouse skeletal phenotypes. Mutations in 11 mouse genes (Ccn6, Cyp2r1, Flna, Galns, Gna13, Lemd3, Manba, Mnx1, Nsd1, Plod1, Smarcal1) do not result in similar skeletal phenotypes observed with mutations of the homologous human genes. These discrepancies can result from failure of mouse models to mimic the exact human gene mutations. There are no obvious commonalities among these 11 genes. Body BMD and/or radiologic dysmorphology phenotypes were successfully identified for 28 genes by the International Mouse Phenotyping Consortium (IMPC). Forward genetics using ENU mouse mutagenesis successfully identified 37 nosology gene phenotypes. Since many human genetic disorders involve hypomorphic, gain-of-function, dominant-negative and intronic mutations, future studies will undoubtedly utilize CRISPR/Cas9 technology to examine transgenic mice having genes modified to exactly mimic variant human sequences. Mutant mice will increasingly be employed for drug development studies designed to treat human genetic skeletal disorders. SIGNIFICANCE Great progress is being made identifying mutant genes responsible for human rare genetic skeletal disorders and mouse models for genes affecting bone mass, architecture, mineralization and strength. This review organizes data for 441 human genetic bone disorders with regard to heredity, gene function, molecular pathways, and fidelity of relevant mouse models to mimic the human skeletal disorders. PubMed weblinks to citations of 249 successful mouse models are provided.
Collapse
Affiliation(s)
- Robert Brommage
- Department of Internal Medicine and Clinical Nutrition, Centre for Bone and Arthritis Research, Institute of Medicine, The Sahlgrenska Academy at University of Gothenburg, Gothenburg, Sweden
- *Correspondence: Robert Brommage
| | - Claes Ohlsson
- Department of Internal Medicine and Clinical Nutrition, Centre for Bone and Arthritis Research, Institute of Medicine, The Sahlgrenska Academy at University of Gothenburg, Gothenburg, Sweden
- Department of Drug Treatment, Sahlgrenska University Hospital, Gothenburg, Sweden
| |
Collapse
|
62
|
Mechanoactivation of Wnt/β-catenin pathways in health and disease. Emerg Top Life Sci 2018; 2:701-712. [DOI: 10.1042/etls20180042] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2018] [Revised: 10/08/2018] [Accepted: 10/09/2018] [Indexed: 11/17/2022]
Abstract
Mechanical forces play an important role in regulating tissue development and homeostasis in multiple cell types including bone, joint, epithelial and vascular cells, and are also implicated in the development of diseases, e.g. osteoporosis, cardiovascular disease and osteoarthritis. Defining the mechanisms by which cells sense and respond to mechanical forces therefore has important implications for our understanding of tissue function in health and disease and may lead to the identification of targets for therapeutic intervention. Mechanoactivation of the Wnt signalling pathway was first identified in osteoblasts with a key role for β-catenin demonstrated in loading-induced osteogenesis. Since then, mechanoregulation of the Wnt pathway has also been observed in stem cells, epithelium, chondrocytes and vascular and lymphatic endothelium. Wnt can signal through both canonical and non-canonical pathways, and evidence suggests that both can mediate responses to mechanical strain, stretch and shear stress. This review will discuss our current understanding of the activation of the Wnt pathway in response to mechanical forces.
Collapse
|
63
|
Loots GG, Robling AG, Chang JC, Murugesh DK, Bajwa J, Carlisle C, Manilay JO, Wong A, Yellowley CE, Genetos DC. Vhl deficiency in osteocytes produces high bone mass and hematopoietic defects. Bone 2018; 116:307-314. [PMID: 30172741 DOI: 10.1016/j.bone.2018.08.022] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/16/2018] [Revised: 08/28/2018] [Accepted: 08/29/2018] [Indexed: 12/11/2022]
Abstract
Tissue oxygen (O2) levels vary during development and disease; adaptations to decreased O2 (hypoxia) are mediated by hypoxia-inducible factor (HIF) transcription factors. HIFs are active in the skeleton, and stabilizing HIF-α isoforms cause high bone mass (HBM) phenotypes. A fundamental limitation of previous studies examining the obligate role for HIF-α isoforms in the skeleton involves the persistence of gene deletion as osteolineage cells differentiate into osteocytes. Because osteocytes orchestrate skeletal development and homeostasis, we evaluated the influence of Vhl or Hif1a disruption in osteocytes. Osteocytic Vhl deletion caused HBM phenotype, but Hif1a was dispensable in osteocytes. Vhl cKO mice revealed enhanced canonical Wnt signaling. B cell development was reduced while myelopoiesis increased in osteocytic Vhl cKO, revealing a novel influence of Vhl/HIF-α function in osteocytes on maintenance of bone microarchitecture via canonical Wnt signaling and effects on hematopoiesis.
Collapse
Affiliation(s)
- Gabriela G Loots
- Lawrence Livermore National Laboratories, Physical and Life Sciences Directorate, Livermore, CA, USA; Molecular Cell Biology Unit, School of Natural Sciences, UC Merced, Merced, CA, USA
| | - Alexander G Robling
- Department of Anatomy and Cell Biology, Indiana University School of Medicine, Indianapolis, IN, USA
| | - Jiun C Chang
- Lawrence Livermore National Laboratories, Physical and Life Sciences Directorate, Livermore, CA, USA; Molecular Cell Biology Unit, School of Natural Sciences, UC Merced, Merced, CA, USA
| | - Deepa K Murugesh
- Lawrence Livermore National Laboratories, Physical and Life Sciences Directorate, Livermore, CA, USA
| | - Jamila Bajwa
- Molecular Cell Biology Unit, School of Natural Sciences, UC Merced, Merced, CA, USA
| | - Cameron Carlisle
- Molecular Cell Biology Unit, School of Natural Sciences, UC Merced, Merced, CA, USA
| | - Jennifer O Manilay
- Molecular Cell Biology Unit, School of Natural Sciences, UC Merced, Merced, CA, USA
| | - Alice Wong
- Department of Anatomy, Physiology, and Cell Biology, School of Veterinary Medicine, University of California Davis, Davis, CA, USA
| | - Clare E Yellowley
- Department of Anatomy, Physiology, and Cell Biology, School of Veterinary Medicine, University of California Davis, Davis, CA, USA
| | - Damian C Genetos
- Department of Anatomy, Physiology, and Cell Biology, School of Veterinary Medicine, University of California Davis, Davis, CA, USA.
| |
Collapse
|
64
|
Kriksciuniene R, Zilaitiene B, Lukosevicius S, Ereminiene E, Klimaite R, Verkauskiene R. The main predictors of the enlargement of ascending aorta in Turner syndrome: a cross-sectional contrast-enhanced magnetic resonance angiography study. MINERVA ENDOCRINOL 2018; 44:185-191. [PMID: 30290692 DOI: 10.23736/s0391-1977.18.02818-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
BACKGROUND The aim of this study was to identify the main predictors of the enlargement of ascending aorta and to assess the possible relation between reduced bone mineral density and a diameter of ascending aorta in the specific Turner syndrome (TS) population. METHODS Fifty adult females diagnosed with TS have been enrolled into the cross-sectional study. Dimensions of ascending aorta have been measured in four positions using thoracic magnetic resonance imaging, Aortic Size Index (ASI) has been calculated. BMD has been assessed on dual-energy-X ray absorptiometry (DXA) in 1-4 lumbar vertebrae and neck of the femur. According to Z Score on DXA two groups have been formed: a group of patients with normal BMD and a group with reduced BMD. Metabolic parameters and the measurements of ascending aorta have been compared between the two groups. RESULTS Extremely high rate of the dilatation of the root of aorta (up to 50%) was identified in this study. The larger ASI has been found in patients with reduced BMD, negative relation between BMD and ASI has been identified, although after the adjustment for SHRT this correlation remained insignificant. In the multivariate analysis, the main factors affecting ASI were age, body surface area and bicuspid aortic valve. CONCLUSIONS The main factors associated with the enlargement of ascending aorta in Turner syndrome were age, body surface area and bicuspid aortic valve, the relation between diameter of ascending aorta and bone mineral density was not identified.
Collapse
Affiliation(s)
- Ruta Kriksciuniene
- Department of Endocrinology, Medical Academy, Lithuanian University of Health Sciences, Kaunas, Lithuania - .,Kauno Klinikos, Department of Endocrinology, Hospital of Lithuanian University of Health Sciences, Kaunas, Lithuania -
| | - Birute Zilaitiene
- Department of Endocrinology, Medical Academy, Lithuanian University of Health Sciences, Kaunas, Lithuania.,Kauno Klinikos, Department of Endocrinology, Hospital of Lithuanian University of Health Sciences, Kaunas, Lithuania
| | - Saulius Lukosevicius
- Department of Radiology, Medical Academy, Lithuanian University of Health Sciences, Kaunas, Lithuania
| | - Egle Ereminiene
- Department of Cardiology, Medical Academy, Lithuanian University Of Health Sciences, Kaunas, Lithuania
| | - Raimonda Klimaite
- Department of Endocrinology, Medical Academy, Lithuanian University of Health Sciences, Kaunas, Lithuania.,Kauno Klinikos, Department of Endocrinology, Hospital of Lithuanian University of Health Sciences, Kaunas, Lithuania
| | - Rasa Verkauskiene
- Department of Endocrinology, Medical Academy, Lithuanian University of Health Sciences, Kaunas, Lithuania.,Kauno Klinikos, Department of Endocrinology, Hospital of Lithuanian University of Health Sciences, Kaunas, Lithuania
| |
Collapse
|
65
|
Xiao L, Fei Y, Hurley MM. FGF2 crosstalk with Wnt signaling in mediating the anabolic action of PTH on bone formation. Bone Rep 2018; 9:136-144. [PMID: 30258857 PMCID: PMC6152810 DOI: 10.1016/j.bonr.2018.09.003] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/09/2018] [Revised: 07/30/2018] [Accepted: 09/20/2018] [Indexed: 12/20/2022] Open
Abstract
The mechanisms of the anabolic effect of parathyroid hormone (PTH) in bone are not fully defined. The bone anabolic effects of PTH require fibroblast growth factor 2 (FGF2) as well as Wnt signaling and FGF2 modulates Wnt signaling in osteoblasts. In vivo PTH administration differentially modulated Wnt signaling in bones of wild type (WT) and in mice that Fgf2 was knocked out (Fgf2KO). PTH increased Wnt10b mRNA and protein in WT but not in KO mice. Wnt antagonist SOST mRNA and protein was significantly higher in KO group. However, PTH decreased Sost mRNA significantly in WT as well as in Fgf2KO mice, but to a lesser extent in Fgf2KO. Dickhopf 2 (DKK2) is critical for osteoblast mineralization. PTH increased Dkk2 mRNA in WT mice but the response was impaired in Fgf2KO mice. PTH significantly increased Lrp5 mRNA and phosphorylation of Lrp6 in WT but the increase was markedly attenuated in Fgf2KO mice. PTH increased β-catenin expression and Wnt/β-catenin transcriptional activity significantly in WT but not in Fgf2KO mice. These data suggest that the impaired bone anabolic response to PTH in Fgf2KO mice is partially mediated by attenuated Wnt signaling. In vivo PTH administration differentially modulated Wnt signaling in bones of WT and Fgf2KO mice. PTH treatment increased WNT10b and DKK2 expression in WT mice but the increase was blunted in Fgf2KO mice PTH increased Lrp5 mRNA and phosphorylation of Lrp6 in WT but the increase was markedly attenuated in Fgf2KO mice. PTH treatment increased β-catenin protein level and Wnt/β-catenin transcriptional activity in WT but not in Fgf2KO mice The impaired bone anabolic response to PTH in Fgf2KO mice is partially mediated by attenuated Wnt signaling.
Collapse
Affiliation(s)
| | | | - Marja M. Hurley
- Corresponding author at: Department of Medicine, University of Connecticut Health Center, 263 Farmington Ave., Farmington, CT 06030, USA.
| |
Collapse
|
66
|
Ramdani G, Schall N, Kalyanaraman H, Wahwah N, Moheize S, Lee JJ, Sah RL, Pfeifer A, Casteel DE, Pilz RB. cGMP-dependent protein kinase-2 regulates bone mass and prevents diabetic bone loss. J Endocrinol 2018; 238:203-219. [PMID: 29914933 PMCID: PMC6086127 DOI: 10.1530/joe-18-0286] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/08/2018] [Accepted: 06/18/2018] [Indexed: 11/08/2022]
Abstract
NO/cGMP signaling is important for bone remodeling in response to mechanical and hormonal stimuli, but the downstream mediator(s) regulating skeletal homeostasis are incompletely defined. We generated transgenic mice expressing a partly-activated, mutant cGMP-dependent protein kinase type 2 (PKG2R242Q) under control of the osteoblast-specific Col1a1 promoter to characterize the role of PKG2 in post-natal bone formation. Primary osteoblasts from these mice showed a two- to three-fold increase in basal and total PKG2 activity; they proliferated faster and were resistant to apoptosis compared to cells from WT mice. Male Col1a1-Prkg2R242Q transgenic mice had increased osteoblast numbers, bone formation rates and Wnt/β-catenin-related gene expression in bone and a higher trabecular bone mass compared to their WT littermates. Streptozotocin-induced type 1 diabetes suppressed bone formation and caused rapid bone loss in WT mice, but male transgenic mice were protected from these effects. Surprisingly, we found no significant difference in bone micro-architecture or Wnt/β-catenin-related gene expression between female WT and transgenic mice; female mice of both genotypes showed higher systemic and osteoblastic NO/cGMP generation compared to their male counterparts, and a higher level of endogenous PKG2 activity may be responsible for masking effects of the PKG2R242Q transgene in females. Our data support sexual dimorphism in Wnt/β-catenin signaling and PKG2 regulation of this crucial pathway in bone homeostasis. This work establishes PKG2 as a key regulator of osteoblast proliferation and post-natal bone formation.
Collapse
Affiliation(s)
- Ghania Ramdani
- Department of MedicineUniversity of California, San Diego, La Jolla, California, USA
| | - Nadine Schall
- Department of MedicineUniversity of California, San Diego, La Jolla, California, USA
- The Institute for Pharmacology and ToxicologyUniversity of Bonn, Bonn, Germany
| | - Hema Kalyanaraman
- Department of MedicineUniversity of California, San Diego, La Jolla, California, USA
| | - Nisreen Wahwah
- Department of MedicineUniversity of California, San Diego, La Jolla, California, USA
| | - Sahar Moheize
- Department of MedicineUniversity of California, San Diego, La Jolla, California, USA
| | - Jenna J Lee
- Department of BioengineeringUniversity of California, San Diego, La Jolla, California, USA
| | - Robert L Sah
- Department of BioengineeringUniversity of California, San Diego, La Jolla, California, USA
| | - Alexander Pfeifer
- The Institute for Pharmacology and ToxicologyUniversity of Bonn, Bonn, Germany
| | - Darren E Casteel
- Department of MedicineUniversity of California, San Diego, La Jolla, California, USA
| | - Renate B Pilz
- Department of MedicineUniversity of California, San Diego, La Jolla, California, USA
| |
Collapse
|
67
|
Chen D, Xie R, Shu B, Landay AL, Wei C, Reiser J, Spagnoli A, Torquati A, Forsyth CB, Keshavarzian A, Sumner DR. Wnt signaling in bone, kidney, intestine, and adipose tissue and interorgan interaction in aging. Ann N Y Acad Sci 2018; 1442:48-60. [PMID: 30101565 DOI: 10.1111/nyas.13945] [Citation(s) in RCA: 40] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2018] [Revised: 07/02/2018] [Accepted: 07/11/2018] [Indexed: 12/12/2022]
Abstract
Over the last two decades, it has become increasingly apparent that Wnt signaling plays a critical role in development and adult tissue homeostasis in multiple organs and in the pathogenesis of many diseases. In particular, a crucial role for Wnt signaling in bone development and bone tissue homeostasis has been well recognized. Numerous genome-wide association studies confirmed the importance of Wnt signaling in controlling bone mass. Moreover, ample evidence suggests that Wnt signaling is essential for kidney, intestine, and adipose tissue development and homeostasis. Recent emerging evidence demonstrates that Wnt signaling may play a fundamental role in the aging process of those organs. New discoveries show that bone is not only the major reservoir for calcium and phosphate storage, but also the largest organ with multiple functions, including mineral and energy metabolism. The interactions among bone, kidney, intestine, and adipose tissue are controlled and regulated by several endocrine signals, including FGF23, klotho, sclerostin, osteocalcin, vitamin D, and leptin. Since the aging process is characterized by structural and functional decline in almost all tissues and organs, understanding the Wnt signaling-related interactions among bone, kidney, intestine, and adipose tissue in aging may shed light on the pathogenesis of age-related diseases.
Collapse
Affiliation(s)
- Di Chen
- Department of Orthopedic Surgery, Rush University Medical Center, Chicago, Illinois
| | - Rong Xie
- Department of Orthopedic Surgery, Rush University Medical Center, Chicago, Illinois
| | - Bing Shu
- Spine Research Institute, Longhua Hospital, Shanghai University of Traditional Chinese Medicine, Shanghai, China
| | - Alan L Landay
- Department of Microbial Pathogens and Immunity, Rush University Medical Center, Chicago, Illinois
| | - Changli Wei
- Department of Internal Medicine, Rush University Medical Center, Chicago, Illinois
| | - Jochen Reiser
- Department of Internal Medicine, Rush University Medical Center, Chicago, Illinois
| | - Anna Spagnoli
- Department of Pediatrics, Rush University Medical Center, Chicago, Illinois
| | - Alfonso Torquati
- Department of Surgery, Rush University Medical Center, Chicago, Illinois
| | | | - Ali Keshavarzian
- Department of Internal Medicine, Rush University Medical Center, Chicago, Illinois
| | - D Rick Sumner
- Department of Cell and Molecular Medicine, Rush University Medical Center, Chicago, Illinois
| |
Collapse
|
68
|
Cao JJ. Caloric restriction combined with exercise is effective in reducing adiposity and mitigating bone structural deterioration in obese rats. Ann N Y Acad Sci 2018; 1433:41-52. [DOI: 10.1111/nyas.13936] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2018] [Revised: 06/27/2018] [Accepted: 06/29/2018] [Indexed: 12/21/2022]
Affiliation(s)
- Jay J. Cao
- USDA, Agricultural Research Service Grand Forks Human Nutrition Research Center Grand Forks North Dakota
| |
Collapse
|
69
|
Seref-Ferlengez Z, Urban-Maldonado M, Sun HB, Schaffler MB, Suadicani SO, Thi MM. Role of pannexin 1 channels in load-induced skeletal response. Ann N Y Acad Sci 2018; 1442:79-90. [PMID: 29952014 DOI: 10.1111/nyas.13914] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2018] [Revised: 05/18/2018] [Accepted: 06/01/2018] [Indexed: 12/31/2022]
Abstract
The pannexin 1 (Panx1) channel is a mechanosensitive channel that interacts with P2X7 receptors (P2X7R) to form a functional complex that has been shown in vitro to play an essential role in osteocyte mechanosignaling. While the participation of P2X7R in skeletal responses to mechanical loading has been demonstrated, the role of Panx1 and its interplay with P2X7R still remain to be determined. In this study, we use a global Panx1-/- mouse model and in vivo mechanical loading to demonstrate that Panx1 channels play an essential role in load-induced skeletal responses. We found that absence of Panx1 not only disrupts the P2X7R-Panx1 signaling complex, but also alters load-induced regulation of P2X7R expression. Moreover, lack of Panx1 completely abolished load-induced periosteal bone formation. Load-induced regulation of β-catenin and sclerostin expression was dysregulated in Panx1-/- , compared to wild-type, bone. This finding suggests that Panx1 deficiency disrupts Wnt/β-catenin signaling by lowering β-catenin while favoring inhibition of bone formation by increasing load-induced sclerostin expression. This study demonstrates the existence of a Panx1-dependent mechanosensitive mechanism that not only modulates ATP signaling but also coordinates Wnt/β-catenin signaling that is essential for proper skeletal response to mechanical loading.
Collapse
Affiliation(s)
- Zeynep Seref-Ferlengez
- Department of Orthopaedic Surgery.,Laboratories of Musculoskeletal Orthopedic Research at Einstein-Montefiore (MORE)
| | - Marcia Urban-Maldonado
- Department of Orthopaedic Surgery.,Laboratories of Musculoskeletal Orthopedic Research at Einstein-Montefiore (MORE).,Department of Urology
| | - Hui B Sun
- Department of Orthopaedic Surgery.,Laboratories of Musculoskeletal Orthopedic Research at Einstein-Montefiore (MORE).,Department of Radiation Oncology
| | - Mitchell B Schaffler
- Department of Biomedical Engineering, City College of New York, New York, New York
| | - Sylvia O Suadicani
- Laboratories of Musculoskeletal Orthopedic Research at Einstein-Montefiore (MORE).,Department of Urology.,Department of Neuroscience, Albert Einstein College of Medicine and Montefiore Medical Center, Bronx, New York
| | - Mia M Thi
- Department of Orthopaedic Surgery.,Laboratories of Musculoskeletal Orthopedic Research at Einstein-Montefiore (MORE).,Department of Neuroscience, Albert Einstein College of Medicine and Montefiore Medical Center, Bronx, New York
| |
Collapse
|
70
|
Zhao G, Huang BL, Rigueur D, Wang W, Bhoot C, Charles KR, Baek J, Mohan S, Jiang J, Lyons KM. CYR61/CCN1 Regulates Sclerostin Levels and Bone Maintenance. J Bone Miner Res 2018; 33:1076-1089. [PMID: 29351359 PMCID: PMC6002906 DOI: 10.1002/jbmr.3394] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/16/2017] [Revised: 01/06/2018] [Accepted: 01/09/2018] [Indexed: 12/19/2022]
Abstract
CYR61/CCN1 is a matricellular protein that resides in the extracellular matrix, but serves regulatory rather than structural roles. CYR61/CCN1 is found in mineralized tissues and has been shown to influence bone healing in vivo and osteogenic differentiation in vitro. In this study we generated Cyr61 bone-specific knockout mice to examine the physiological role of CYR61/CCN1 in bone development and maintenance in vivo. Extensive analysis of Cyr61 conditional knockout mice showed a significant decrease in both trabecular and cortical bone mass as compared to WT littermates. Our data suggest that CYR61/CCN1 exerts its effects on mature osteoblast/osteocyte function to modulate bone mass. Specifically, changes were observed in osteocyte/osteoblast expression of RankL, VegfA, and Sost. The increase in RankL expression was correlated with a significant increase in osteoclast number; decreased VegfA expression was correlated with a significant decrease in bone vasculature; increased Sost expression was associated with decreased Wnt signaling, as revealed by decreased Axin2 expression and increased adiposity in the bone marrow. Although the decreased number of vascular elements in bone likely contributes to the low bone mass phenotype in Cyr61 conditional knockout mice, this cannot explain the observed increase in osteoclasts and the decrease in Wnt signaling. We conducted in vitro assays using UMR-106 osteosarcoma cells to explore the role CYR61/CCN1 plays in modulating Sost mRNA and protein expression in osteocytes and osteoblasts. Overexpression of CYR61/CCN1 can suppress Sost expression in both control and Cyr61 knockout cells, and blocking Sost with siRNA can rescue Wnt responsiveness in Cyr61 knockout cells in vitro. Overall, our data suggest that CYR61/CCN1 modulates mature osteoblast and osteocyte function to regulate bone mass through angiogenic effects as well as by modulating Wnt signaling, at least in part through the Wnt antagonist Sost. © 2018 American Society for Bone and Mineral Research.
Collapse
Affiliation(s)
- Gexin Zhao
- Department of Orthopaedic Surgery, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, USA
| | - Bau-Lin Huang
- Center for Cancer Research, National Cancer Institute, Frederick, MD, USA
| | - Diana Rigueur
- Department of Orthopaedic Surgery, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, USA
| | - Weiguang Wang
- Department of Orthopaedic Surgery, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, USA
| | - Chimay Bhoot
- Department of Orthopaedic Surgery, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, USA
| | - Kemberly R Charles
- Department of Orthopaedic Surgery, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, USA
| | - Jongseung Baek
- Department of Orthopaedic Surgery, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, USA
- Department of Molecular, Cell and Developmental Biology, University of California, Los Angeles, Los Angeles, CA, USA
| | - Subburaman Mohan
- Musculoskeletal Disease Center, Jerry L. Pettis Memorial VA Medical Center, Loma Linda, CA, USA
- Department of Medicine, Loma Linda University, Loma Linda, CA, USA
| | - Jie Jiang
- Department of Orthopaedic Surgery, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, USA
- School of Dentistry, University of California, Los Angeles, Los Angeles, CA, USA
- Hemophilia Treatment Center, Orthopaedic Institute for Children, Los Angeles, CA, USA
| | - Karen M Lyons
- Department of Orthopaedic Surgery, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, USA
- Department of Molecular, Cell and Developmental Biology, University of California, Los Angeles, Los Angeles, CA, USA
| |
Collapse
|
71
|
Morse A, Schindeler A, McDonald MM, Kneissel M, Kramer I, Little DG. Sclerostin Antibody Augments the Anabolic Bone Formation Response in a Mouse Model of Mechanical Tibial Loading. J Bone Miner Res 2018; 33:486-498. [PMID: 29090474 DOI: 10.1002/jbmr.3330] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/27/2017] [Revised: 10/11/2017] [Accepted: 10/29/2017] [Indexed: 12/18/2022]
Abstract
Decreased activity or expression of sclerostin, an endogenous inhibitor of Wnt/β-catenin signaling, results in increased bone formation and mass. Antibodies targeting and neutralizing sclerostin (Scl-Ab) have been shown to increase bone mass and reduce fracture risk. Sclerostin is also important in modulating the response of bone to changes in its biomechanical environment. However, the effects of Scl-Ab on mechanotransduction are unclear, and it was speculated that the loading response may be altered for individuals receiving Scl-Ab therapy. To address this, we carried out a 2-week study of tibial cyclic compressive loading on C57Bl/6 mice treated with vehicle or 100 mg/kg/wk Scl-Ab. Increases in bone volume, density, and dynamic bone formation were found with loading, and the anabolic response was further increased by the combination of load and Scl-Ab. To investigate the underlying mechanism, gene profiling by RNA sequencing (RNAseq) was performed on tibias isolated from mice from all four experimental groups. Major alterations in Wnt/β-catenin gene expression were found with tibial loading, however not with Scl-Ab treatment alone. Notably, the combination of load and Scl-Ab elicited a synergistic response from a number of specific Wnt-related and mechanotransduction factors. An unexpected finding was significant upregulation of factors in the Rho GTPase signaling pathway with combination treatment. In summary, combination therapy had a more profound anabolic response than either Scl-Ab or loading treatment alone. The Wnt/β-catenin and Rho GTPase pathways were implicated within bone mechanotransduction and support the concept that bone mechanotransduction is likely to encompass a number of interconnected signaling pathways. © 2017 American Society for Bone and Mineral Research.
Collapse
Affiliation(s)
- Alyson Morse
- Orthopaedic Research & Biotechnology Unit, The Children's Hospital at Westmead, Westmead, Australia.,Discipline of Paediatrics and Child Health, Sydney Medical School, University of Sydney, Sydney, Australia
| | - Aaron Schindeler
- Orthopaedic Research & Biotechnology Unit, The Children's Hospital at Westmead, Westmead, Australia.,Discipline of Paediatrics and Child Health, Sydney Medical School, University of Sydney, Sydney, Australia
| | - Michelle M McDonald
- Bone Biology Program, The Garvan Institute of Medical Research, Darlinghurst, Australia
| | | | | | - David G Little
- Orthopaedic Research & Biotechnology Unit, The Children's Hospital at Westmead, Westmead, Australia.,Discipline of Paediatrics and Child Health, Sydney Medical School, University of Sydney, Sydney, Australia
| |
Collapse
|
72
|
Canalis E. MANAGEMENT OF ENDOCRINE DISEASE: Novel anabolic treatments for osteoporosis. Eur J Endocrinol 2018; 178:R33-R44. [PMID: 29113980 PMCID: PMC5819362 DOI: 10.1530/eje-17-0920] [Citation(s) in RCA: 57] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/03/2017] [Revised: 11/07/2017] [Accepted: 11/07/2017] [Indexed: 12/15/2022]
Abstract
Skeletal anabolic agents enhance bone formation, which is determined by the number and function of osteoblasts. Signals that influence the differentiation and function of cells of the osteoblast lineage play a role in the mechanism of action of anabolic agents in the skeleton. Wnts induce the differentiation of mesenchymal stem cells toward osteoblasts, and insulin-like growth factor I (IGF-I) enhances the function of mature osteoblasts. The activity of Wnt and IGF-I is controlled by proteins that bind to the growth factor or to its receptors. Sclerostin is a Wnt antagonist that binds to Wnt co-receptors and prevents Wnt signal activation. Teriparatide, a 1-34 amino terminal fragment of parathyroid hormone (PTH), and abaloparatide, a modified 1-34 amino terminal fragment of PTH-related peptide (PTHrp), induce IGF-I, increase bone mineral density (BMD), reduce the incidence of vertebral and non-vertebral fractures and are approved for the treatment of postmenopausal osteoporosis. Romosozumab, a humanized anti-sclerostin antibody, increases bone formation, decreases bone resorption, increases BMD and reduces the incidence of vertebral fractures. An increased incidence of cardiovascular events has been associated with romosozumab, which is yet to be approved for the treatment of osteoporosis. In conclusion, cell and molecular studies have formed the foundation for the development of new anabolic therapies for osteoporosis with proven efficacy on the incidence of new fractures.
Collapse
Affiliation(s)
- Ernesto Canalis
- Departments of Orthopaedic Surgery and Medicine, UConn Musculoskeletal Institute, UConn Health, Farmington, Connecticut, USA
| |
Collapse
|
73
|
Sun D, Brodt MD, Zannit HM, Holguin N, Silva MJ. Evaluation of loading parameters for murine axial tibial loading: Stimulating cortical bone formation while reducing loading duration. J Orthop Res 2018; 36:682-691. [PMID: 28888055 PMCID: PMC5839947 DOI: 10.1002/jor.23727] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/10/2017] [Accepted: 08/31/2017] [Indexed: 02/04/2023]
Abstract
Classic studies in bone mechanobiology have established the importance of loading parameters on the anabolic response. Most of these early studies were done using loading methods not currently in favor, and using non-murine species. Our objective was to re-examine the effects of several loading parameters on the response of cortical bone using the contemporary murine axial tibial compression model. We subjected tibias of 5-month old, female C57Bl/6 mice to cyclic (4 Hz) mechanical loading and examined bone formation responses using dynamic and static histomorphometry. First, using a reference protocol of 1,200 cycles/day, 5 days/week for 2 weeks, we confirmed the significant influence of peak strain magnitude on periosteal mineralizing surface (Ps.MS/BS) and bone formation rate (Ps.BFR/BS) (p < 0.05, ANOVA). There was a significant induction of periosteal lamellar bone at a lower threshold of approx. -1,000 μϵ and a transition from lamellar-woven bone near -2,000 μϵ. In contrast, on the endocortical surface, bone formation indices did not exhibit a load magnitude-dependent response and no incidence of woven bone. Next, we found that reducing daily cycle number from 1,200 to 300 to 60 did not diminish the bone formation response (p > 0.05). On the other hand, reducing the daily frequency of loading from 5 consecutive days/week to 3 alternate days/week significantly diminished the periosteal response, from a loading-induced increase in Ps.MS/BS of 38% (loaded vs. control) for 5 days/week to only 15% for 3 days/week (p < 0.05). Finally, we determined that reducing the study duration from 2 to 1 weeks of loading did not affect bone formation outcomes. In conclusion, cyclic loading to -1,800 μϵ peak strain, at 4 Hz and 60 cycles/day for 5 consecutive days (1 week) induces an increase in periosteal lamellar bone formation with minimal incidence of woven bone in 5-month-old C57Bl/6 female mice. Our results provide a basis for reduction of loading duration (daily cycles and study length) without loss of anabolic effect as measured by dynamic histomorphometry. © 2017 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 36:682-691, 2018.
Collapse
Affiliation(s)
- David Sun
- Department of Orthopaedic Surgery, Washington University in Saint
Louis, Saint Louis, Missouri,Department of Biomedical Engineering, Washington University in Saint
Louis, Saint Louis, Missouri
| | - Michael D. Brodt
- Department of Orthopaedic Surgery, Washington University in Saint
Louis, Saint Louis, Missouri
| | - Heather M. Zannit
- Department of Orthopaedic Surgery, Washington University in Saint
Louis, Saint Louis, Missouri,Department of Biomedical Engineering, Washington University in Saint
Louis, Saint Louis, Missouri
| | - Nilsson Holguin
- Department of Orthopaedic Surgery, Washington University in Saint
Louis, Saint Louis, Missouri
| | - Matthew J. Silva
- Department of Orthopaedic Surgery, Washington University in Saint
Louis, Saint Louis, Missouri,Department of Biomedical Engineering, Washington University in Saint
Louis, Saint Louis, Missouri,Correspondence To: Matthew J. Silva, Ph.D.,
, Dept. of Orthopaedic Surgery/Campus Box
8233, Washington University School of Medicine, 660 S. Euclid Ave, St. Louis, MO
63110
| |
Collapse
|
74
|
Bird IM, Kim SH, Schweppe DK, Caetano-Lopes J, Robling AG, Charles JF, Gygi SP, Warman ML, Smits PJ. The skeletal phenotype of achondrogenesis type 1A is caused exclusively by cartilage defects. Development 2018; 145:dev.156588. [PMID: 29180569 PMCID: PMC5825869 DOI: 10.1242/dev.156588] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2017] [Accepted: 11/16/2017] [Indexed: 12/12/2022]
Abstract
Inactivating mutations in the ubiquitously expressed membrane trafficking component GMAP-210 (encoded by Trip11) cause achondrogenesis type 1A (ACG1A). ACG1A is surprisingly tissue specific, mainly affecting cartilage development. Bone development is also abnormal, but as chondrogenesis and osteogenesis are closely coupled, this could be a secondary consequence of the cartilage defect. A possible explanation for the tissue specificity of ACG1A is that cartilage and bone are highly secretory tissues with a high use of the membrane trafficking machinery. The perinatal lethality of ACG1A prevents investigating this hypothesis. We therefore generated mice with conditional Trip11 knockout alleles and inactivated Trip11 in chondrocytes, osteoblasts, osteoclasts and pancreas acinar cells, all highly secretory cell types. We discovered that the ACG1A skeletal phenotype is solely due to absence of GMAP-210 in chondrocytes. Mice lacking GMAP-210 in osteoblasts, osteoclasts and acinar cells were normal. When we inactivated Trip11 in primary chondrocyte cultures, GMAP-210 deficiency affected trafficking of a subset of chondrocyte-expressed proteins rather than globally impairing membrane trafficking. Thus, GMAP-210 is essential for trafficking specific cargoes in chondrocytes but is dispensable in other highly secretory cells. Summary: Conditional inactivation of the cis-Golgin GMAP-210 reveals that the skeletal phenotype in achondrogenesis type-1A, which is caused by mutations in GMAP-210, is solely due to impaired protein trafficking by chondrocytes.
Collapse
Affiliation(s)
- Ian M Bird
- Orthopaedic Research Laboratories, Department of Orthopaedic Surgery, Boston Children's Hospital, Boston, MA 02115, USA
| | - Susie H Kim
- Orthopaedic Research Laboratories, Department of Orthopaedic Surgery, Boston Children's Hospital, Boston, MA 02115, USA
| | - Devin K Schweppe
- Department of Cell Biology, Harvard Medical School, Boston, MA 02115, USA
| | - Joana Caetano-Lopes
- Orthopaedic Research Laboratories, Department of Orthopaedic Surgery, Boston Children's Hospital, Boston, MA 02115, USA
| | - Alexander G Robling
- Department of Anatomy and Cell Biology, Indiana University, Indianapolis, IN 46202, USA
| | - Julia F Charles
- Department of Medicine, Brigham and Women's Hospital, Boston, MA 02115, USA
| | - Steven P Gygi
- Department of Cell Biology, Harvard Medical School, Boston, MA 02115, USA
| | - Matthew L Warman
- Orthopaedic Research Laboratories, Department of Orthopaedic Surgery, Boston Children's Hospital, Boston, MA 02115, USA.,Howard Hughes Medical Institute, Boston Children's Hospital, Boston, MA 02115, USA.,Department of Genetics, Harvard Medical School, Boston, MA 02115, USA
| | - Patrick J Smits
- Orthopaedic Research Laboratories, Department of Orthopaedic Surgery, Boston Children's Hospital, Boston, MA 02115, USA
| |
Collapse
|
75
|
Bisson SK, Ung RV, Mac-Way F. Role of the Wnt/ β-Catenin Pathway in Renal Osteodystrophy. Int J Endocrinol 2018; 2018:5893514. [PMID: 29808090 PMCID: PMC5901476 DOI: 10.1155/2018/5893514] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/25/2018] [Accepted: 03/08/2018] [Indexed: 12/17/2022] Open
Abstract
Vascular calcification and bone fragility are common and interrelated health problems that affect chronic kidney disease (CKD) patients. Bone fragility, which leads to higher risk of fracture and mortality, arises from the abnormal bone remodeling and mineralization that are seen in chronic kidney disease. Recently, sclerostin and Dickkopf-related protein 1 were suggested to play a significant role in CKD-related bone disease as they are known inhibitors of the Wnt pathway, thus preventing bone formation. This review focuses on new knowledge about the Wnt pathway in bone, how its function is affected by chronic kidney disease and how this affects bone structure. Expression of components and inhibitors of the Wnt pathway has been shown to be affected by the loss of kidney function, and a better understanding of the bone effects of Wnt pathway inhibitors could allow the development of new therapies to prevent bone fragility in this population.
Collapse
Affiliation(s)
- Sarah-Kim Bisson
- Faculty and Department of Medicine, CHU de Québec Research Center, L'Hôtel-Dieu de Québec Hospital, Endocrinology and Nephrology Axis, Université Laval, Quebec, Canada
| | - Roth-Visal Ung
- Faculty and Department of Medicine, CHU de Québec Research Center, L'Hôtel-Dieu de Québec Hospital, Endocrinology and Nephrology Axis, Université Laval, Quebec, Canada
| | - Fabrice Mac-Way
- Faculty and Department of Medicine, CHU de Québec Research Center, L'Hôtel-Dieu de Québec Hospital, Endocrinology and Nephrology Axis, Université Laval, Quebec, Canada
| |
Collapse
|
76
|
Caetano-Lopes J, Lessard SG, Hann S, Espinoza K, Kang KS, Lim KE, Horan DJ, Noonan HR, Hu D, Baron R, Robling AG, Warman ML. Clcn7 F318L/+ as a new mouse model of Albers-Schönberg disease. Bone 2017; 105:253-261. [PMID: 28942122 PMCID: PMC5752150 DOI: 10.1016/j.bone.2017.09.007] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/19/2017] [Revised: 09/08/2017] [Accepted: 09/15/2017] [Indexed: 12/21/2022]
Abstract
Dominant negative mutations in CLCN7, which encodes a homodimeric chloride channel needed for matrix acidification by osteoclasts, cause Albers-Schönberg disease (also known as autosomal dominant osteopetrosis type 2). More than 25 different CLCN7 mutations have been identified in patients affected with Albers-Schönberg disease, but only one mutation (Clcn7G213R) has been introduced in mice to create an animal model of this disease. Here we describe a mouse with a different osteopetrosis-causing mutation (Clcn7F318L). Compared to Clcn7+/+ mice, 12-week-old Clcn7F318L/+ mice have significantly increased trabecular bone volume, consistent with Clcn7F318L acting as a dominant negative mutation. Clcn7F318L/F318L and Clcn7F318L/G213R mice die by 1month of age and resemble Clcn7 knockout mice, which indicate that p.F318L mutant protein is non-functional and p.F318L and p.G213R mutant proteins do not complement one another. Since it has been reported that treatment with interferon gamma (IFN-G) improves bone properties in Clcn7G213R/+ mice, we treated Clcn7F318L/+ mice with IFN-G and observed a decrease in osteoclast number and mineral apposition rate, but no overall improvement in bone properties. Our results suggest that the benefits of IFN-G therapy in patients with Albers-Schönberg disease may be mutation-specific.
Collapse
Affiliation(s)
- J Caetano-Lopes
- Orthopaedic Research Laboratories, Boston Children's Hospital, Boston, MA, USA; Department of Genetics, Harvard Medical School, Boston, MA, USA
| | - S G Lessard
- Orthopaedic Research Laboratories, Boston Children's Hospital, Boston, MA, USA; Department of Genetics, Harvard Medical School, Boston, MA, USA
| | - S Hann
- Orthopaedic Research Laboratories, Boston Children's Hospital, Boston, MA, USA; Department of Genetics, Harvard Medical School, Boston, MA, USA
| | - K Espinoza
- Howard Hughes Medical Institute, Boston Children's Hospital, Boston, MA, USA
| | - K S Kang
- Department of Anatomy and Cell Biology, Indiana University School of Medicine, Indianapolis, IN, USA
| | - K E Lim
- Department of Anatomy and Cell Biology, Indiana University School of Medicine, Indianapolis, IN, USA
| | - D J Horan
- Department of Anatomy and Cell Biology, Indiana University School of Medicine, Indianapolis, IN, USA
| | - H R Noonan
- BBS Program, Harvard Medical School, Boston, MA, USA
| | - D Hu
- Division of Bone and Mineral Research, Harvard School of Dental Medicine, Boston, MA, USA
| | - R Baron
- Division of Bone and Mineral Research, Harvard School of Dental Medicine, Boston, MA, USA
| | - A G Robling
- Department of Anatomy and Cell Biology, Indiana University School of Medicine, Indianapolis, IN, USA
| | - M L Warman
- Orthopaedic Research Laboratories, Boston Children's Hospital, Boston, MA, USA; Department of Genetics, Harvard Medical School, Boston, MA, USA; Howard Hughes Medical Institute, Boston Children's Hospital, Boston, MA, USA.
| |
Collapse
|
77
|
Yu W, Zheng Y, Yang Z, Fei H, Wang Y, Hou X, Sun X, Shen Y. N-AC-l-Leu-PEI-mediated miR-34a delivery improves osteogenic differentiation under orthodontic force. Oncotarget 2017; 8:110460-110473. [PMID: 29299161 PMCID: PMC5746396 DOI: 10.18632/oncotarget.22790] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2017] [Accepted: 11/14/2017] [Indexed: 01/08/2023] Open
Abstract
Rare therapeutic genes or agents are reported to control orthodontic bone remodeling. MicroRNAs have recently been associated with bone metabolism. Here, we report the in vitro and in vivo effects of miR-34a on osteogenic differentiation under orthodontic force using an N-acetyl-L-leucine-modified polyethylenimine (N-Ac-l-Leu-PEI) carrier. N-Ac-l-Leu-PEI exhibited low cytotoxicity and high miR-34a transfection efficiency in rat bone mineral stem cells and local alveolar bone tissue. After transfection, miR-34a enhanced the osteogenic differentiation of Runx2 and ColI, Runx2 and ColI protein levels, and early osteogenesis function under orthodontic strain in vitro. MiR-34a also enhanced alveolar bone remodeling under orthodontic force in vivo, as evidenced by elevated gene and protein expression, upregulated indices of alveolar bone anabolism, and diminished tooth movement. We determined that the mechanism miR-34a in osteogenesis under orthodontic force may be associated with GSK-3β. These results suggested that miR-34a delivered by N-Ac-l-Leu-PEI could be a potential therapeutic target for orthodontic treatment.
Collapse
Affiliation(s)
- Wenwen Yu
- Department of Orthodontics, School and Hospital of Stomatology, Jilin University, Changchun 130021, China
| | - Yi Zheng
- Department of Periodontics, School and Hospital of Stomatology, Jilin University, Changchun 130021, China
| | - Zhujun Yang
- Department of Orthodontics, School and Hospital of Stomatology, Jilin University, Changchun 130021, China
| | - Hongbo Fei
- Department of Periodontics, School and Hospital of Stomatology, Jilin University, Changchun 130021, China
| | - Yang Wang
- Department of Orthodontics, School and Hospital of Stomatology, Jilin University, Changchun 130021, China
| | - Xu Hou
- Department of Orthodontics, School and Hospital of Stomatology, Jilin University, Changchun 130021, China
| | - Xinhua Sun
- Department of Orthodontics, School and Hospital of Stomatology, Jilin University, Changchun 130021, China
| | - Yuqin Shen
- Department of Periodontics, School and Hospital of Stomatology, Jilin University, Changchun 130021, China
| |
Collapse
|
78
|
Sebastian A, Hum NR, Murugesh DK, Hatsell S, Economides AN, Loots GG. Wnt co-receptors Lrp5 and Lrp6 differentially mediate Wnt3a signaling in osteoblasts. PLoS One 2017; 12:e0188264. [PMID: 29176883 PMCID: PMC5703471 DOI: 10.1371/journal.pone.0188264] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2017] [Accepted: 11/05/2017] [Indexed: 01/10/2023] Open
Abstract
Wnt3a is a major regulator of bone metabolism however, very few of its target genes are known in bone. Wnt3a preferentially signals through transmembrane receptors Frizzled and co-receptors Lrp5/6 to activate the canonical signaling pathway. Previous studies have shown that the canonical Wnt co-receptors Lrp5 and Lrp6 also play an essential role in normal postnatal bone homeostasis, yet, very little is known about specific contributions by these co-receptors in Wnt3a-dependent signaling. We used high-throughput sequencing technology to identify target genes regulated by Wnt3a in osteoblasts and to elucidate the role of Lrp5 and Lrp6 in mediating Wnt3a signaling. Our study identified 782 genes regulated by Wnt3a in primary calvarial osteoblasts. Wnt3a up-regulated the expression of several key regulators of osteoblast proliferation/ early stages of differentiation while inhibiting genes expressed in later stages of osteoblastogenesis. We also found that Lrp6 is the key mediator of Wnt3a signaling in osteoblasts and Lrp5 played a less significant role in mediating Wnt3a signaling.
Collapse
Affiliation(s)
- Aimy Sebastian
- Lawrence Livermore National Laboratories, Physical and Life Sciences Directorate, Livermore, CA, United States of America
- UC Merced, School of Natural Sciences, Merced, CA, United States of America
| | - Nicholas R. Hum
- Lawrence Livermore National Laboratories, Physical and Life Sciences Directorate, Livermore, CA, United States of America
- UC Merced, School of Natural Sciences, Merced, CA, United States of America
| | - Deepa K. Murugesh
- Lawrence Livermore National Laboratories, Physical and Life Sciences Directorate, Livermore, CA, United States of America
| | - Sarah Hatsell
- Regeneron Pharmaceuticals, Tarrytown, NY, United States of America
| | | | - Gabriela G. Loots
- Lawrence Livermore National Laboratories, Physical and Life Sciences Directorate, Livermore, CA, United States of America
- UC Merced, School of Natural Sciences, Merced, CA, United States of America
- * E-mail:
| |
Collapse
|
79
|
Johnson MG, Konicke K, Kristianto J, Gustavson A, Garbo R, Wang X, Yuan B, Blank RD. Endothelin signaling regulates mineralization and posttranscriptionally regulates SOST in TMOb cells via miR 126-3p. Physiol Rep 2017; 5:5/4/e13088. [PMID: 28235973 PMCID: PMC5328763 DOI: 10.14814/phy2.13088] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2016] [Revised: 11/14/2016] [Accepted: 11/15/2016] [Indexed: 11/24/2022] Open
Abstract
Previously, our laboratory identified ECE‐1, encoding endothelin‐converting enzyme‐1 (ECE‐1), as a positional candidate for a pleiotropic quantitative trait locus affecting femoral size, shape, and biomechanical performance. We hypothesized that endothelin‐1 (ET‐1) signaling promotes osteogenesis. Exposure of immortalized mouse osteoblast (TMOb) cells to big ET‐1 increased mineralization. Following big ET‐1 treatment, we measured the secretion of insulin‐like‐growth factor‐1 (IGF1), dickkopf‐homolog‐1 protein 1 (DKK1), and sclerostin (SOST). In each case, big ET‐1 signaling changed secretion in a manner that favored increased osteogenic activity. Treatment with ECE‐1, endothelin receptor A (EDNRA), or WNT receptor antagonists inhibited the big ET‐1‐mediated increase in mineralization. In the presence of big ET‐1, message levels of Runx2, Igf1, Dkk1, and Sost are uncoupled from protein production, suggesting posttranscriptional regulation. To evaluate the role of big ET‐1 in normal bone physiology, we inhibited EDNRA signaling during mineralization in the absence of exogenous ET‐1. EDNRA blockade reduced mineralization, decreased IGF1, and increased DKK1 and SOST secretion, responses opposite to those induced by exogenous big ET‐1. Pharmacological and siRNA knockdown to inhibit ECE‐1 reduced mineralization and IGF1 secretion with decreasing DKK1 and decreasing or stable SOST secretion, suggesting a further, unknown role of ECE‐1 in osteoblast maturation. Previously we identified miR 126‐3p as a potential ET‐1‐responsive regulator of SOST in murine cells. Overexpression of miR126‐3p increased mineralization in TMOb cells and decreased SOST secretion. Osteoblasts express the ET‐1 signaling pathway and ET‐1 signaling is necessary for normal osteoblast differentiation and mineralization, acting through regulation of miRs that target osteogenic molecules.
Collapse
Affiliation(s)
- Michael G Johnson
- Geriatrics Research, Education and Clinical Center, William S. Middleton Veterans Affairs Hospital, Madison, Wisconsin .,Division of Endocrinology, Department of Medicine, University of Wisconsin-Madison, Madison, Wisconsin
| | - Kathryn Konicke
- Medical Service, Clement J. Zablocki Veterans Affairs Medical Center, Milwaukee, Wisconsin.,Division of Endocrinology, Department of Medicine, Medical College of Wisconsin, Milwaukee, Wisconsin
| | - Jasmin Kristianto
- Geriatrics Research, Education and Clinical Center, William S. Middleton Veterans Affairs Hospital, Madison, Wisconsin.,Division of Endocrinology, Department of Medicine, University of Wisconsin-Madison, Madison, Wisconsin
| | - Anne Gustavson
- Geriatrics Research, Education and Clinical Center, William S. Middleton Veterans Affairs Hospital, Madison, Wisconsin.,Division of Endocrinology, Department of Medicine, University of Wisconsin-Madison, Madison, Wisconsin
| | - Rachel Garbo
- Geriatrics Research, Education and Clinical Center, William S. Middleton Veterans Affairs Hospital, Madison, Wisconsin.,Division of Endocrinology, Department of Medicine, University of Wisconsin-Madison, Madison, Wisconsin
| | - Xiaohu Wang
- Medical Service, Clement J. Zablocki Veterans Affairs Medical Center, Milwaukee, Wisconsin.,Division of Endocrinology, Department of Medicine, Medical College of Wisconsin, Milwaukee, Wisconsin
| | - Baozhi Yuan
- Geriatrics Research, Education and Clinical Center, William S. Middleton Veterans Affairs Hospital, Madison, Wisconsin.,Division of Endocrinology, Department of Medicine, University of Wisconsin-Madison, Madison, Wisconsin
| | - Robert D Blank
- Geriatrics Research, Education and Clinical Center, William S. Middleton Veterans Affairs Hospital, Madison, Wisconsin.,Medical Service, Clement J. Zablocki Veterans Affairs Medical Center, Milwaukee, Wisconsin.,Division of Endocrinology, Department of Medicine, Medical College of Wisconsin, Milwaukee, Wisconsin
| |
Collapse
|
80
|
Affiliation(s)
- T John Martin
- St Vincent's Institute of Medical Research, University of Melbourne Department of Medicine, Fitzroy, Australia
| |
Collapse
|
81
|
Yang T, Williams BO. Low-Density Lipoprotein Receptor-Related Proteins in Skeletal Development and Disease. Physiol Rev 2017; 97:1211-1228. [PMID: 28615463 DOI: 10.1152/physrev.00013.2016] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2016] [Revised: 03/07/2017] [Accepted: 03/15/2017] [Indexed: 02/06/2023] Open
Abstract
The identification of the low-density lipoprotein receptor (LDLR) provided a foundation for subsequent studies in lipoprotein metabolism, receptor-mediated endocytosis, and many other fundamental biological functions. The importance of the LDLR led to numerous studies that identified homologous molecules and ultimately resulted in the description of the LDL-receptor superfamily, a group of proteins that contain domains also found in the LDLR. Subsequent studies have revealed that members of the LDLR-related protein family play roles in regulating many aspects of signal transduction. This review is focused on the roles of selected members of this protein family in skeletal development and disease. We present background on the identification of this subgroup of receptors, discuss the phenotypes associated with alterations in their function in human patients and mouse models, and describe the current efforts to therapeutically target these proteins to treat human skeletal disease.
Collapse
Affiliation(s)
- Tao Yang
- Program in Skeletal Disease and Tumor Microenvironment, Center for Cancer and Cell Biology, Van Andel Research Institute, Grand Rapids, Michigan
| | - Bart O Williams
- Program in Skeletal Disease and Tumor Microenvironment, Center for Cancer and Cell Biology, Van Andel Research Institute, Grand Rapids, Michigan
| |
Collapse
|
82
|
Abstract
PURPOSE OF REVIEW The goal of this paper is to evaluate critically the literature published over the past 3 years regarding the Wnt signaling pathway. The Wnt pathway was found to be involved in bone biology in 2001-2002 with the discovery of a (G171V) mutation in the lipoprotein receptor-related protein 5 (LRP5) that resulted in high bone mass and another mutation that completely inactivated Lrp5 function and resulted in osteoporosis pseudoglioma syndrome (OPPG). The molecular biology has been complex, and very interesting. It has provided many opportunities for exploitation to develop new clinical treatments, particularly for osteoporosis. More clinical possibilities include: treatments for fracture healing, corticosteroid osteoporosis, osteogenesis imperfecta, and others. In addition, we wish to provide historical information coming from distant publications (~350 years ago) regarding bone biology that have been confirmed by study of Wnt signaling. RECENT FINDINGS A recent finding is the development of an antibody to sclerostin that is under study as a treatment for osteoporosis. Development of treatments for other forms of osteoporosis, such as corticosteroid osteoporosis, is also underway. The full range of the applications of the work is not yet been achieved.
Collapse
Affiliation(s)
- Mark L Johnson
- Department of Oral and Craniofacial Sciences, UMKC School of Dentistry, 650 East 25th Street, Kansas City, MO, 64108, USA
| | - Robert R Recker
- Creighton University, 601 N 30th St., Ste 4841, Omaha, NE, 68131, USA.
| |
Collapse
|
83
|
Chen X, Guo J, Yuan Y, Sun Z, Chen B, Tong X, Zhang L, Shen C, Zou J. Cyclic compression stimulates osteoblast differentiation via activation of the Wnt/β-catenin signaling pathway. Mol Med Rep 2017; 15:2890-2896. [DOI: 10.3892/mmr.2017.6327] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2016] [Accepted: 01/23/2017] [Indexed: 11/06/2022] Open
|
84
|
Evidence of the Role of R-Spondin 1 and Its Receptor Lgr4 in the Transmission of Mechanical Stimuli to Biological Signals for Bone Formation. Int J Mol Sci 2017; 18:ijms18030564. [PMID: 28272338 PMCID: PMC5372580 DOI: 10.3390/ijms18030564] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2017] [Revised: 02/23/2017] [Accepted: 02/28/2017] [Indexed: 01/28/2023] Open
Abstract
The bone can adjust its mass and architecture to mechanical stimuli via a series of molecular cascades, which have been not yet fully elucidated. Emerging evidence indicated that R-spondins (Rspos), a family of secreted agonists of the Wnt/β-catenin signaling pathway, had important roles in osteoblastic differentiation and bone formation. However, the role of Rspo proteins in mechanical loading-influenced bone metabolism has never been investigated. In this study, we found that Rspo1 was a mechanosensitive protein for bone formation. Continuous cyclic mechanical stretch (CMS) upregulated the expression of Rspo1 in mouse bone marrow mesenchymal stem cells (BMSCs), while the expression of Rspo1 in BMSCs in vivo was downregulated in the bones of a mechanical unloading mouse model (tail suspension (TS)). On the other hand, Rspo1 could promote osteogenesis of BMSCs under CMS through activating the Wnt/β-catenin signaling pathway and could rescue the bone loss induced by mechanical unloading in the TS mice. Specifically, our results suggested that Rspo1 and its receptor of leucine-rich repeat containing G-protein-coupled receptor 4 (Lgr4) should be a novel molecular signal in the transmission of mechanical stimuli to biological signal in the bone, and this signal should be in the upstream of Wnt/β-catenin signaling for bone formation. Rspo1/Lgr4 could be a new potential target for the prevention and treatment of disuse osteoporosis in the future.
Collapse
|
85
|
Delgado-Calle J, Tu X, Pacheco-Costa R, McAndrews K, Edwards R, Pellegrini GG, Kuhlenschmidt K, Olivos N, Robling A, Peacock M, Plotkin LI, Bellido T. Control of Bone Anabolism in Response to Mechanical Loading and PTH by Distinct Mechanisms Downstream of the PTH Receptor. J Bone Miner Res 2017; 32:522-535. [PMID: 27704638 PMCID: PMC8502039 DOI: 10.1002/jbmr.3011] [Citation(s) in RCA: 78] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/09/2016] [Revised: 09/30/2016] [Accepted: 10/04/2016] [Indexed: 12/31/2022]
Abstract
Osteocytes integrate the responses of bone to mechanical and hormonal stimuli by poorly understood mechanisms. We report here that mice with conditional deletion of the parathyroid hormone (PTH) receptor 1 (Pth1r) in dentin matrix protein 1 (DMP1)-8kb-expressing cells (cKO) exhibit a modest decrease in bone resorption leading to a mild increase in cancellous bone without changes in cortical bone. However, bone resorption in response to endogenous chronic elevation of PTH in growing or adult cKO mice induced by a low calcium diet remained intact, because the increased bone remodeling and bone loss was indistinguishable from that exhibited by control littermates. In contrast, the bone gain and increased bone formation in cancellous and cortical bone induced by daily injections of PTH and the periosteal bone apposition induced by axial ulna loading were markedly reduced in cKO mice compared to controls. Remarkably, however, wild-type (WT) control littermates and transgenic mice overexpressing SOST injected daily with PTH exhibit similar activation of Wnt/β-catenin signaling, increased bone formation, and cancellous and cortical bone gain. Taken together, these findings demonstrate that Pth1r in DMP1-8kb-expressing cells is required to maintain basal levels of bone resorption but is dispensable for the catabolic action of chronic PTH elevation; and it is essential for the anabolic actions of daily PTH injections and mechanical loading. However, downregulation of Sost/sclerostin, previously shown to be required for bone anabolism induced by mechanical loading, is not required for PTH-induced bone gain, showing that other mechanisms downstream of the Pth1r in DMP1-8kb-expressing cells are responsible for the hormonal effect. © 2016 American Society for Bone and Mineral Research.
Collapse
Affiliation(s)
- Jesus Delgado-Calle
- Department of Anatomy and Cell Biology, School of Medicine, Indiana University, Indianapolis, IN, USA.,Roudebush Veterans Administration Medical Center, Indianapolis, IN, USA
| | - Xiaolin Tu
- Department of Anatomy and Cell Biology, School of Medicine, Indiana University, Indianapolis, IN, USA
| | - Rafael Pacheco-Costa
- Department of Anatomy and Cell Biology, School of Medicine, Indiana University, Indianapolis, IN, USA
| | - Kevin McAndrews
- Department of Anatomy and Cell Biology, School of Medicine, Indiana University, Indianapolis, IN, USA.,Roudebush Veterans Administration Medical Center, Indianapolis, IN, USA
| | - Rachel Edwards
- Department of Anatomy and Cell Biology, School of Medicine, Indiana University, Indianapolis, IN, USA
| | - Gretel G Pellegrini
- Department of Anatomy and Cell Biology, School of Medicine, Indiana University, Indianapolis, IN, USA
| | - Kali Kuhlenschmidt
- Department of Anatomy and Cell Biology, School of Medicine, Indiana University, Indianapolis, IN, USA
| | - Naomie Olivos
- Department of Anatomy and Cell Biology, School of Medicine, Indiana University, Indianapolis, IN, USA
| | - Alexander Robling
- Department of Anatomy and Cell Biology, School of Medicine, Indiana University, Indianapolis, IN, USA.,Roudebush Veterans Administration Medical Center, Indianapolis, IN, USA.,Department of Biomedical Engineering, Indiana University-Purdue University at Indianapolis, Indianapolis, IN, USA
| | - Munro Peacock
- Department of Medicine, Division of Endocrinology, School of Medicine, Indiana University, Indianapolis, IN, USA
| | - Lilian I Plotkin
- Department of Anatomy and Cell Biology, School of Medicine, Indiana University, Indianapolis, IN, USA.,Roudebush Veterans Administration Medical Center, Indianapolis, IN, USA
| | - Teresita Bellido
- Department of Anatomy and Cell Biology, School of Medicine, Indiana University, Indianapolis, IN, USA.,Roudebush Veterans Administration Medical Center, Indianapolis, IN, USA.,Department of Medicine, Division of Endocrinology, School of Medicine, Indiana University, Indianapolis, IN, USA
| |
Collapse
|
86
|
Maycas M, McAndrews KA, Sato AY, Pellegrini GG, Brown DM, Allen MR, Plotkin LI, Gortazar AR, Esbrit P, Bellido T. PTHrP-Derived Peptides Restore Bone Mass and Strength in Diabetic Mice: Additive Effect of Mechanical Loading. J Bone Miner Res 2017; 32:486-497. [PMID: 27683064 DOI: 10.1002/jbmr.3007] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/07/2016] [Revised: 09/23/2016] [Accepted: 09/27/2016] [Indexed: 01/17/2023]
Abstract
There is an unmet need to understand the mechanisms underlying skeletal deterioration in diabetes mellitus (DM) and to develop therapeutic approaches to treat bone fragility in diabetic patients. We demonstrate herein that mice with type 1 DM induced by streptozotocin exhibited low bone mass, inferior mechanical and material properties, increased bone resorption, decreased bone formation, increased apoptosis of osteocytes, and increased expression of the osteocyte-derived bone formation inhibitor Sost/sclerostin. Further, short treatment of diabetic mice with parathyroid hormone related protein (PTHrP)-derived peptides corrected these changes to levels undistinguishable from non-diabetic mice. In addition, diabetic mice exhibited reduced bone formation in response to mechanical stimulation, which was corrected by treatment with the PTHrP peptides, and higher prevalence of apoptotic osteocytes, which was reduced by loading or by the PTHrP peptides alone and reversed by a combination of loading and PTHrP peptide treatment. In vitro experiments demonstrated that the PTHrP peptides or mechanical stimulation by fluid flow activated the survival kinases ERKs and induced nuclear translocation of the canonical Wnt signaling mediator β-catenin, and prevented the increase in osteocytic cell apoptosis induced by high glucose. Thus, PTHrP-derived peptides cross-talk with mechanical signaling pathways to reverse skeletal deterioration induced by DM in mice. These findings suggest a crucial role of osteocytes in the harmful effects of diabetes on bone and raise the possibility of targeting these cells as a novel approach to treat skeletal deterioration in diabetes. Moreover, our study suggests the potential therapeutic efficacy of combined pharmacological and mechanical stimuli to promote bone accrual and maintenance in diabetic subjects. © 2016 American Society for Bone and Mineral Research.
Collapse
Affiliation(s)
- Marta Maycas
- Department of Anatomy and Cell Biology, Indiana University School of Medicine, Indianapolis, IN, USA.,Instituto de Investigación Sanitaria-Fundación Jiménez Díaz, Madrid, Spain
| | - Kevin A McAndrews
- Department of Anatomy and Cell Biology, Indiana University School of Medicine, Indianapolis, IN, USA.,Roudebush Veterans Administration Medical Center, Indianapolis, IN, USA
| | - Amy Y Sato
- Department of Anatomy and Cell Biology, Indiana University School of Medicine, Indianapolis, IN, USA
| | - Gretel G Pellegrini
- Department of Anatomy and Cell Biology, Indiana University School of Medicine, Indianapolis, IN, USA
| | - Drew M Brown
- Department of Anatomy and Cell Biology, Indiana University School of Medicine, Indianapolis, IN, USA
| | - Matthew R Allen
- Department of Anatomy and Cell Biology, Indiana University School of Medicine, Indianapolis, IN, USA
| | - Lilian I Plotkin
- Department of Anatomy and Cell Biology, Indiana University School of Medicine, Indianapolis, IN, USA.,Roudebush Veterans Administration Medical Center, Indianapolis, IN, USA
| | - Arancha R Gortazar
- Instituto de Medicina Molecular Aplicada-Universidad San Pablo CEU, Madrid, Spain
| | - Pedro Esbrit
- Instituto de Investigación Sanitaria-Fundación Jiménez Díaz, Madrid, Spain
| | - Teresita Bellido
- Department of Anatomy and Cell Biology, Indiana University School of Medicine, Indianapolis, IN, USA.,Roudebush Veterans Administration Medical Center, Indianapolis, IN, USA.,Department of Medicine, Division of Endocrinology, Indiana University School of Medicine, Indianapolis, IN, USA
| |
Collapse
|
87
|
Hinton PS, Nigh P, Thyfault J. Serum sclerostin decreases following 12months of resistance- or jump-training in men with low bone mass. Bone 2017; 96:85-90. [PMID: 27744012 PMCID: PMC5328803 DOI: 10.1016/j.bone.2016.10.011] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/13/2016] [Revised: 09/07/2016] [Accepted: 10/10/2016] [Indexed: 12/17/2022]
Abstract
PURPOSE We previously reported that 12months of resistance training (RT, 2×/wk, N=19) or jump training (JUMP, 3×/wk, N=19) increased whole body and lumbar spine BMD and increased serum bone formation markers relative to resorption in physically active (≥4h/wk) men (mean age: 44±2y; median: 44y) with osteopenia of the hip or spine. The purpose of this secondary analysis was to examine the effects of the RT or JUMP intervention on potential endocrine mediators of the exercise effects on bone, specifically IGF-I, PTH and sclerostin. METHODS Fasting blood samples were collected after a 24-h period of no exercise at baseline and after 12months of RT or JUMP. IGF-I, PTH and sclerostin were measured in serum by ELISA. The effects of RT or JUMP on IGF-I, PTH and sclerostin were evaluated using 2×2 repeated measures ANOVA (time, group). This study was conducted in accordance with the Declaration of Helsinki and was approved by the University of Missouri IRB. RESULTS Sclerostin concentrations in serum significantly decreased and IGF-I significantly increased after 12months of RT or JUMP; while PTH remained unchanged. CONCLUSION The beneficial effects of long-term, progressive-intensity RT or JUMP on BMD in moderately active men with low bone mass are associated with decreased sclerostin and increased IGF-I.
Collapse
Affiliation(s)
- Pamela S Hinton
- Department of Nutrition and Exercise Physiology, University of Missouri, Columbia, MO 65211, United States.
| | - Peggy Nigh
- Department of Nutrition and Exercise Physiology, University of Missouri, Columbia, MO 65211, United States
| | - John Thyfault
- Department of Nutrition and Exercise Physiology, University of Missouri, Columbia, MO 65211, United States; Internal Medicine - Division of GI and Hepatology, University of Missouri, Columbia, MO 65211, United States
| |
Collapse
|
88
|
Abstract
The endothelin (ET) system includes 3 small peptide hormones and a pair of G-protein-coupled receptors. This review first outlines the ET signaling pathway and ET metabolism. Next, it summarizes the role of ET1 signaling in craniofacial development. Then, it discusses observations relating ET signaling to osteoblastic and other osteosclerotic processes in cancer. Finally, it describes recent work in our laboratory that points to endothelin signaling as an upstream mediator of WNT signaling, promoting bone matrix synthesis and mineralization. It concludes with a statement of some remaining gaps in knowledge and proposals for future research.
Collapse
Affiliation(s)
- Jasmin Kristianto
- Divisions of Endocrinology, Metabolism, and Clinical Nutrition, Department of Medicine, Medical College of Wisconsin, 9200 West Wisconsin Avenue, Milwaukee, WI 53226, USA
| | - Michael G Johnson
- Department of Medicine, University of Wisconsin, 600 Highland Avenue, Madison, WI 53792, USA
| | - Rafia Afzal
- Department of Anesthesiology, Aga Khan University Hospital, Stadium Road, Karachi 74800, Pakistan
| | - Robert D Blank
- Divisions of Endocrinology, Metabolism, and Clinical Nutrition, Department of Medicine, Medical College of Wisconsin, 9200 West Wisconsin Avenue, Milwaukee, WI 53226, USA; Medical Service, Clement J. Zablocki VAMC, 5000 West National Avenue, Milwaukee, WI 53295, USA.
| |
Collapse
|
89
|
Jacobsen CM. Application of anti-Sclerostin therapy in non-osteoporosis disease models. Bone 2017; 96:18-23. [PMID: 27780792 PMCID: PMC5328800 DOI: 10.1016/j.bone.2016.10.018] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/30/2016] [Revised: 10/17/2016] [Accepted: 10/20/2016] [Indexed: 12/29/2022]
Abstract
Sclerostin, a known inhibitor of the low density lipoprotein related protein 5 and 6 (LRP5 and LRP6) cell surface signaling receptors, is integral in the maintenance of normal bone mass and strength. Patients with loss of function mutations in SOST or missense mutations in LRP5 that prevent Sclerostin from binding and inhibiting the receptor, have significantly increased bone mass. This observation leads to the development of Sclerostin neutralizing therapies to increase bone mass and strength. Anti-Sclerostin therapy has been shown to be effective at increasing bone density and strength in animal models and patients with osteoporosis. Loss of function of Sost or treatment with a Sclerostin neutralizing antibody improves bone properties in animal models of Osteoporosis Pseudoglioma syndrome (OPPG), likely due to action through the LRP6 receptor, which suggests patients may benefit from these therapies. Sclerostin antibody is effective at improving bone properties in mouse models of Osteogenesis Imperfecta, a genetic disorder of low bone mass and fragility due to type I collagen mutations, in as little as two weeks after initiation of therapy. However, these improvements are due to increases in bone quantity as the quality (brittleness) of bone remains unaffected. Similarly, Sclerostin antibody treatment improves bone density in animal models of other diseases. Sclerostin neutralizing therapies are likely to benefit many patients with genetic disorders of bone, as well as other forms of metabolic bone disease.
Collapse
Affiliation(s)
- Christina M Jacobsen
- Orthopaedic Research Laboratories, Department of Orthopaedic Surgery, Boston Children's Hospital, Boston, MA, United States; Division of Endocrinology, Boston Children's Hospital, Boston, MA, United States; Division of Genetics, Boston Children's Hospital, Boston, MA, United States; Department of Pediatrics, Harvard Medical School, Boston, MA, United States.
| |
Collapse
|
90
|
Pathogenic LRRK2 variants are gain-of-function mutations that enhance LRRK2-mediated repression of β-catenin signaling. Mol Neurodegener 2017; 12:9. [PMID: 28103901 PMCID: PMC5248453 DOI: 10.1186/s13024-017-0153-4] [Citation(s) in RCA: 43] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2016] [Accepted: 01/06/2017] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND LRRK2 mutations and risk variants increase susceptibility to inherited and idiopathic Parkinson's disease, while recent studies have identified potential protective variants. This, and the fact that LRRK2 mutation carriers develop symptoms and brain pathology almost indistinguishable from idiopathic Parkinson's disease, has led to enormous interest in this protein. LRRK2 has been implicated in a range of cellular events, but key among them is canonical Wnt signalling, which results in increased levels of transcriptionally active β-catenin. This pathway is critical for the development and survival of the midbrain dopaminergic neurones typically lost in Parkinson's disease. METHODS Here we use Lrrk2 knockout mice and fibroblasts to investigate the effect of loss of Lrrk2 on canonical Wnt signalling in vitro and in vivo. Micro-computed tomography was used to study predicted tibial strength, while pulldown assays were employed to measure brain β-catenin levels. A combination of luciferase assays, immunofluorescence and co-immunoprecipitation were performed to measure canonical Wnt activity and investigate the relationship between LRRK2 and β-catenin. TOPflash assays are also used to study the effects of LRRK2 kinase inhibition and pathogenic and protective LRRK2 mutations on Wnt signalling. Data were tested by Analysis of Variance. RESULTS Loss of Lrrk2 causes a dose-dependent increase in the levels of transcriptionally active β-catenin in the brain, and alters tibial bone architecture, decreasing the predicted risk of fracture. Lrrk2 knockout cells display increased TOPflash and Axin2 promoter activities, both basally and following Wnt activation. Consistently, over-expressed LRRK2 was found to bind β-catenin and repress TOPflash activation. Some pathogenic LRRK2 mutations and risk variants further suppressed TOPflash, whereas the protective R1398H variant increased Wnt signalling activity. LRRK2 kinase inhibitors affected canonical Wnt signalling differently due to off-targeting; however, specific LRRK2 inhibition reduced canonical Wnt signalling similarly to pathogenic mutations. CONCLUSIONS Loss of LRRK2 causes increased canonical Wnt activity in vitro and in vivo. In agreement, over-expressed LRRK2 binds and represses β-catenin, suggesting LRRK2 may act as part of the β-catenin destruction complex. Since some pathogenic LRRK2 mutations enhance this effect while the protective R1398H variant relieves it, our data strengthen the notion that decreased canonical Wnt activity is central to Parkinson's disease pathogenesis.
Collapse
|
91
|
Shapses SA, Pop LC, Wang Y. Obesity is a concern for bone health with aging. Nutr Res 2017; 39:1-13. [PMID: 28385284 DOI: 10.1016/j.nutres.2016.12.010] [Citation(s) in RCA: 99] [Impact Index Per Article: 14.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2016] [Revised: 12/16/2016] [Accepted: 12/27/2016] [Indexed: 02/08/2023]
Abstract
Accumulating evidence supports a complex relationship between adiposity and osteoporosis in overweight/obese individuals, with local interactions and endocrine regulation by adipose tissue on bone metabolism and fracture risk in elderly populations. This review was conducted to summarize existing evidence to test the hypothesis that obesity is a risk factor for bone health in aging individuals. Mechanisms by which obesity adversely affects bone health are believed to be multiple, such as an alteration of bone-regulating hormones, inflammation, oxidative stress, the endocannabinoid system, that affect bone cell metabolism are discussed. In addition, evidence on the effect of fat mass and distribution on bone mass and quality is reviewed together with findings relating energy and fat intake with bone health. In summary, studies indicate that the positive effects of body weight on bone mineral density cannot counteract the detrimental effects of obesity on bone quality. However, the exact mechanism underlying bone deterioration in the obese is not clear yet and further research is required to elucidate the effect of adipose depots on bone and fracture risk in the obese population.
Collapse
Affiliation(s)
- Sue A Shapses
- Department of Nutritional Sciences, Rutgers University, New Brunswick, NJ.
| | - L Claudia Pop
- Department of Nutritional Sciences, Rutgers University, New Brunswick, NJ
| | - Yang Wang
- Department of Nutritional Sciences, Rutgers University, New Brunswick, NJ
| |
Collapse
|
92
|
Almeida M, Laurent MR, Dubois V, Claessens F, O'Brien CA, Bouillon R, Vanderschueren D, Manolagas SC. Estrogens and Androgens in Skeletal Physiology and Pathophysiology. Physiol Rev 2017; 97:135-187. [PMID: 27807202 PMCID: PMC5539371 DOI: 10.1152/physrev.00033.2015] [Citation(s) in RCA: 460] [Impact Index Per Article: 65.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Estrogens and androgens influence the growth and maintenance of the mammalian skeleton and are responsible for its sexual dimorphism. Estrogen deficiency at menopause or loss of both estrogens and androgens in elderly men contribute to the development of osteoporosis, one of the most common and impactful metabolic diseases of old age. In the last 20 years, basic and clinical research advances, genetic insights from humans and rodents, and newer imaging technologies have changed considerably the landscape of our understanding of bone biology as well as the relationship between sex steroids and the physiology and pathophysiology of bone metabolism. Together with the appreciation of the side effects of estrogen-related therapies on breast cancer and cardiovascular diseases, these advances have also drastically altered the treatment of osteoporosis. In this article, we provide a comprehensive review of the molecular and cellular mechanisms of action of estrogens and androgens on bone, their influences on skeletal homeostasis during growth and adulthood, the pathogenetic mechanisms of the adverse effects of their deficiency on the female and male skeleton, as well as the role of natural and synthetic estrogenic or androgenic compounds in the pharmacotherapy of osteoporosis. We highlight latest advances on the crosstalk between hormonal and mechanical signals, the relevance of the antioxidant properties of estrogens and androgens, the difference of their cellular targets in different bone envelopes, the role of estrogen deficiency in male osteoporosis, and the contribution of estrogen or androgen deficiency to the monomorphic effects of aging on skeletal involution.
Collapse
Affiliation(s)
- Maria Almeida
- Division of Endocrinology and Metabolism, Center for Osteoporosis and Metabolic Bone Diseases, University of Arkansas for Medical Sciences and the Central Arkansas Veterans Healthcare System, Little Rock, Arkansas; Departments of Cellular and Molecular Medicine and Clinical and Experimental Medicine, KU Leuven, Leuven, Belgium; Center for Metabolic Bone Diseases, University Hospitals Leuven, Leuven, Belgium; and Institut National de la Santé et de la Recherche Médicale UMR1011, University of Lille and Institut Pasteur de Lille, Lille, France
| | - Michaël R Laurent
- Division of Endocrinology and Metabolism, Center for Osteoporosis and Metabolic Bone Diseases, University of Arkansas for Medical Sciences and the Central Arkansas Veterans Healthcare System, Little Rock, Arkansas; Departments of Cellular and Molecular Medicine and Clinical and Experimental Medicine, KU Leuven, Leuven, Belgium; Center for Metabolic Bone Diseases, University Hospitals Leuven, Leuven, Belgium; and Institut National de la Santé et de la Recherche Médicale UMR1011, University of Lille and Institut Pasteur de Lille, Lille, France
| | - Vanessa Dubois
- Division of Endocrinology and Metabolism, Center for Osteoporosis and Metabolic Bone Diseases, University of Arkansas for Medical Sciences and the Central Arkansas Veterans Healthcare System, Little Rock, Arkansas; Departments of Cellular and Molecular Medicine and Clinical and Experimental Medicine, KU Leuven, Leuven, Belgium; Center for Metabolic Bone Diseases, University Hospitals Leuven, Leuven, Belgium; and Institut National de la Santé et de la Recherche Médicale UMR1011, University of Lille and Institut Pasteur de Lille, Lille, France
| | - Frank Claessens
- Division of Endocrinology and Metabolism, Center for Osteoporosis and Metabolic Bone Diseases, University of Arkansas for Medical Sciences and the Central Arkansas Veterans Healthcare System, Little Rock, Arkansas; Departments of Cellular and Molecular Medicine and Clinical and Experimental Medicine, KU Leuven, Leuven, Belgium; Center for Metabolic Bone Diseases, University Hospitals Leuven, Leuven, Belgium; and Institut National de la Santé et de la Recherche Médicale UMR1011, University of Lille and Institut Pasteur de Lille, Lille, France
| | - Charles A O'Brien
- Division of Endocrinology and Metabolism, Center for Osteoporosis and Metabolic Bone Diseases, University of Arkansas for Medical Sciences and the Central Arkansas Veterans Healthcare System, Little Rock, Arkansas; Departments of Cellular and Molecular Medicine and Clinical and Experimental Medicine, KU Leuven, Leuven, Belgium; Center for Metabolic Bone Diseases, University Hospitals Leuven, Leuven, Belgium; and Institut National de la Santé et de la Recherche Médicale UMR1011, University of Lille and Institut Pasteur de Lille, Lille, France
| | - Roger Bouillon
- Division of Endocrinology and Metabolism, Center for Osteoporosis and Metabolic Bone Diseases, University of Arkansas for Medical Sciences and the Central Arkansas Veterans Healthcare System, Little Rock, Arkansas; Departments of Cellular and Molecular Medicine and Clinical and Experimental Medicine, KU Leuven, Leuven, Belgium; Center for Metabolic Bone Diseases, University Hospitals Leuven, Leuven, Belgium; and Institut National de la Santé et de la Recherche Médicale UMR1011, University of Lille and Institut Pasteur de Lille, Lille, France
| | - Dirk Vanderschueren
- Division of Endocrinology and Metabolism, Center for Osteoporosis and Metabolic Bone Diseases, University of Arkansas for Medical Sciences and the Central Arkansas Veterans Healthcare System, Little Rock, Arkansas; Departments of Cellular and Molecular Medicine and Clinical and Experimental Medicine, KU Leuven, Leuven, Belgium; Center for Metabolic Bone Diseases, University Hospitals Leuven, Leuven, Belgium; and Institut National de la Santé et de la Recherche Médicale UMR1011, University of Lille and Institut Pasteur de Lille, Lille, France
| | - Stavros C Manolagas
- Division of Endocrinology and Metabolism, Center for Osteoporosis and Metabolic Bone Diseases, University of Arkansas for Medical Sciences and the Central Arkansas Veterans Healthcare System, Little Rock, Arkansas; Departments of Cellular and Molecular Medicine and Clinical and Experimental Medicine, KU Leuven, Leuven, Belgium; Center for Metabolic Bone Diseases, University Hospitals Leuven, Leuven, Belgium; and Institut National de la Santé et de la Recherche Médicale UMR1011, University of Lille and Institut Pasteur de Lille, Lille, France
| |
Collapse
|
93
|
Holguin N, Brodt MD, Silva MJ. Activation of Wnt Signaling by Mechanical Loading Is Impaired in the Bone of Old Mice. J Bone Miner Res 2016; 31:2215-2226. [PMID: 27357062 PMCID: PMC5397287 DOI: 10.1002/jbmr.2900] [Citation(s) in RCA: 99] [Impact Index Per Article: 12.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/20/2016] [Revised: 06/24/2016] [Accepted: 06/27/2016] [Indexed: 01/18/2023]
Abstract
Aging diminishes bone formation engendered by mechanical loads, but the mechanism for this impairment remains unclear. Because Wnt signaling is required for optimal loading-induced bone formation, we hypothesized that aging impairs the load-induced activation of Wnt signaling. We analyzed dynamic histomorphometry of 5-month-old, 12-month-old, and 22-month-old C57Bl/6JN mice subjected to multiple days of tibial compression and corroborated an age-related decline in the periosteal loading response on day 5. Similarly, 1 day of loading increased periosteal and endocortical bone formation in young-adult (5-month-old) mice, but old (22-month-old) mice were unresponsive. These findings corroborated mRNA expression of genes related to bone formation and the Wnt pathway in tibias after loading. Multiple bouts (3 to 5 days) of loading upregulated bone formation-related genes, e.g., Osx and Col1a1, but older mice were significantly less responsive. Expression of Wnt negative regulators, Sost and Dkk1, was suppressed with a single day of loading in all mice, but suppression was sustained only in young-adult mice. Moreover, multiple days of loading repeatedly suppressed Sost and Dkk1 in young-adult, but not in old tibias. The age-dependent response to loading was further assessed by osteocyte staining for Sclerostin and LacZ in tibia of TOPGAL mice. After 1 day of loading, fewer osteocytes were Sclerostin-positive and, corroboratively, more osteocytes were LacZ-positive (Wnt active) in both 5-month-old and 12-month-old mice. However, although these changes were sustained after multiple days of loading in 5-month-old mice, they were not sustained in 12-month-old mice. Last, Wnt1 and Wnt7b were the most load-responsive of the 19 Wnt ligands. However, 4 hours after a single bout of loading, although their expression was upregulated threefold to 10-fold in young-adult mice, it was not altered in old mice. In conclusion, the reduced bone formation response of aged mice to loading may be due to failure to sustain Wnt activity with repeated loading. © 2016 American Society for Bone and Mineral Research.
Collapse
Affiliation(s)
- Nilsson Holguin
- Department of Orthopaedic Surgery, Musculoskeletal Research Center, Washington University, St. Louis, MO, USA
| | - Michael D Brodt
- Department of Orthopaedic Surgery, Musculoskeletal Research Center, Washington University, St. Louis, MO, USA
| | - Matthew J Silva
- Department of Orthopaedic Surgery, Musculoskeletal Research Center, Washington University, St. Louis, MO, USA
- Department of Biomedical Engineering, Washington University, St. Louis, MO, USA
| |
Collapse
|
94
|
Kristianto J, Johnson MG, Afzal R, Blank RD. WITHDRAWN: Endothelin signaling in bone. Transl Res 2016:S1931-5244(16)30366-8. [PMID: 27893988 DOI: 10.1016/j.trsl.2016.11.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/23/2016] [Revised: 10/27/2016] [Accepted: 11/03/2016] [Indexed: 11/17/2022]
Affiliation(s)
- Jasmin Kristianto
- Endocrine and Reproductive Physiology Program, University of Wisconsin, Madison, Wis; Geriatrics Research, Education, and Clinical Center, William S. Middleton Veterans Hospital, Madison, Wis; Department of Medicine, University of Wisconsin, Madison, Wis; Division of Endocrinology, Metabolism, and Clinical Nutrition, Department of Medicine, Medical College of Wisconsin, Milwaukee, Wis
| | - Michael G Johnson
- Endocrine and Reproductive Physiology Program, University of Wisconsin, Madison, Wis; Geriatrics Research, Education, and Clinical Center, William S. Middleton Veterans Hospital, Madison, Wis; Department of Medicine, University of Wisconsin, Madison, Wis
| | - Rafia Afzal
- Department of Anesthesiology, Aga Khan University Hospital, Karachi, Pakistan
| | - Robert D Blank
- Endocrine and Reproductive Physiology Program, University of Wisconsin, Madison, Wis; Geriatrics Research, Education, and Clinical Center, William S. Middleton Veterans Hospital, Madison, Wis; Division of Endocrinology, Metabolism, and Clinical Nutrition, Department of Medicine, Medical College of Wisconsin, Milwaukee, Wis; Medical Service, Clement J. Zablocki VAMC, Milwaukee, Wis
| |
Collapse
|
95
|
Yuan Y, Chen X, Zhang L, Wu J, Guo J, Zou D, Chen B, Sun Z, Shen C, Zou J. The roles of exercise in bone remodeling and in prevention and treatment of osteoporosis. PROGRESS IN BIOPHYSICS AND MOLECULAR BIOLOGY 2016; 122:122-130. [DOI: 10.1016/j.pbiomolbio.2015.11.005] [Citation(s) in RCA: 66] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/29/2015] [Revised: 11/25/2015] [Accepted: 11/27/2015] [Indexed: 12/23/2022]
|
96
|
Abstract
Osteocytes are differentiated osteoblasts that become surrounded by matrix during the process of bone formation. Acquisition of the osteocyte phenotype is achieved by profound changes in gene expression that facilitate adaptation to the changing cellular environment and constitute the molecular signature of osteocytes. During osteocytogenesis, the expression of genes that are characteristic of the osteoblast are altered and the expression of genes and/or proteins that impart dendritic cellular morphology, regulate matrix mineralization and control the function of cells at the bone surface are ordely modulated. The discovery of mutations in human osteocytic genes has contributed, in a large part, to our understanding of the role of osteocytes in bone homeostasis. Osteocytes are targets of the mechanical force imposed on the skeleton and have a critical role in integrating mechanosensory pathways with the action of hormones, which thereby leads to the orchestrated response of bone to environmental cues. Current, therapeutic approaches harness this accumulating knowledge by targeting osteocytic signalling pathways and messengers to improve skeletal health.
Collapse
Affiliation(s)
- Lilian I. Plotkin
- Department of Anatomy and Cell Biology, Indiana University School of Medicine
- Roudebush Veterans Administration Medical Center, Indianapolis, IN
| | - Teresita Bellido
- Department of Anatomy and Cell Biology, Indiana University School of Medicine
- Department of Medicine, Division of Endocrinology, Indiana University School of Medicine
- Roudebush Veterans Administration Medical Center, Indianapolis, IN
| |
Collapse
|
97
|
Liu X, Li M, Zhu Y, Yeung KWK, Chu PK, Wu S. The modulation of stem cell behaviors by functionalized nanoceramic coatings on Ti-based implants. Bioact Mater 2016; 1:65-76. [PMID: 29744396 PMCID: PMC5883996 DOI: 10.1016/j.bioactmat.2016.09.001] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2016] [Revised: 09/01/2016] [Accepted: 09/01/2016] [Indexed: 12/25/2022] Open
Abstract
Nanoceramic coating on the surface of Ti-based metallic implants is a clinical potential option in orthopedic surgery. Stem cells have been found to have osteogenic capabilities. It is necessary to study the influences of functionalized nanoceramic coatings on the differentiation and proliferation of stem cells in vitro or in vivo. In this paper, we summarized the recent advance on the modulation of stem cells behaviors through controlling the properties of nanoceramic coatings, including surface chemistry, surface roughness and microporosity. In addition, mechanotransduction pathways have also been discussed to reveal the interaction mechanisms between the stem cells and ceramic coatings on Ti-based metals. In the final part, the osteoinduction and osteoconduction of ceramic coating have been also presented when it was used as carrier of BMPs in new bone formation. The effects of basic physical properties like roughness, topography and porous stucture of ceramic coatings on the stem cells behaviors on Ti-based alloys have been reviewed together. The chemical way to modulate the cell behaviors is also discussed in this review paper; and the related mechanotransduction pathways have been described in this paper.
Collapse
Affiliation(s)
- Xiangmei Liu
- Hubei Collaborative Innovation Center for Advanced Organic Chemical Materials, Ministry-of-Education Key Laboratory for the Green Preparation and Application of Functional Materials, Hubei Key Laboratory of Polymer Materials, Faculty of Materials Science & Engineering, Hubei University, Wuhan 430062, China
| | - Man Li
- Hubei Collaborative Innovation Center for Advanced Organic Chemical Materials, Ministry-of-Education Key Laboratory for the Green Preparation and Application of Functional Materials, Hubei Key Laboratory of Polymer Materials, Faculty of Materials Science & Engineering, Hubei University, Wuhan 430062, China
| | - Yizhou Zhu
- Hubei Collaborative Innovation Center for Advanced Organic Chemical Materials, Ministry-of-Education Key Laboratory for the Green Preparation and Application of Functional Materials, Hubei Key Laboratory of Polymer Materials, Faculty of Materials Science & Engineering, Hubei University, Wuhan 430062, China
| | - K W K Yeung
- Shenzhen Key Laboratory for Innovative Technology in Orthopaedic Trauma, The University of Hong Kong Shenzhen Hospital, 1 Haiyuan 1st Road, Futian District, Shenzhen, China.,Division of Spine Surgery, Department of Orthopaedics & Traumatology, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Pokfulam, Hong Kong, China
| | - Paul K Chu
- Department of Physics & Materials Science, City University of Hong Kong, Tat Chee Avenue, Kowloon, Hong Kong, China
| | - Shuilin Wu
- Hubei Collaborative Innovation Center for Advanced Organic Chemical Materials, Ministry-of-Education Key Laboratory for the Green Preparation and Application of Functional Materials, Hubei Key Laboratory of Polymer Materials, Faculty of Materials Science & Engineering, Hubei University, Wuhan 430062, China
| |
Collapse
|
98
|
Kitjaroentham A, Hananantachai H, Phonrat B, Preutthipan S, Tungtrongchitr R. Low density lipoprotein receptor-related protein 5 gene polymorphisms and osteoporosis in Thai menopausal women. J Negat Results Biomed 2016; 15:16. [PMID: 27582019 PMCID: PMC5007848 DOI: 10.1186/s12952-016-0059-7] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2015] [Accepted: 08/17/2016] [Indexed: 11/13/2022] Open
Abstract
Background Osteoporosis, characterized by low bone mineral density (BMD) and high bone fracture risk, is prevalent in Thai menopausal women. Genetic factors are known to play a key role in BMD. Low density lipoprotein receptor-related protein 5 (LRP5), a co-receptor in the Wnt/beta-catenin pathway, is involved in many aspects of bone biology. As coding single nucleotide polymorphisms (cSNPs) of LRP5, including A1330V (rs3736228), and Asian-related Q89R (rs41494349) and N740N (rs2306862), are associated with lowered BMD, this study aimed to determine the relationship between these LRP5 polymorphisms and BMD in 277 Thai menopausal women. Results Only rs3736228 deviated from the Hardy–Weinberg equilibrium of allele frequency (p = 0.022). The median, range and p value for the BMD related to each SNP parameter were compared (Mann–Whitney U test). Significant differences were observed between wild-type and risk alleles for both rs3736228 (total radial, p = 0.011; and radial 33, p = 0.001) and rs2306862 (radial 33: p = 0.015) SNPs, with no significant difference for rs41494349 SNP. Linkage disequilibrium was strong for both rs3736228 and rs2306862 SNPs. Haplotype analysis identified high CC frequency in both normal and osteopenia/osteoporosis groups, with a significant odds ratio for carrying the TT haplotype; however, this was non-significant after adjusting for age. Multivariate binary logistic regression analysis performed for rs3736228 showed that individuals with a body mass index <25 kg/m2 had an increased risk of osteoporosis for each decade, but the polymorphism had no effect. Conclusions This study did not identify LRP5 polymorphisms as a risk factor for osteoporosis in Thai menopausal women. Further studies with larger sample sizes are needed to further clarify the role of LRP5 as a genetic determinant of osteoporosis. Electronic supplementary material The online version of this article (doi:10.1186/s12952-016-0059-7) contains supplementary material, which is available to authorized users.
Collapse
Affiliation(s)
- Anong Kitjaroentham
- Department of Tropical Nutrition and Food Science, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand.
| | - Hathairad Hananantachai
- Department of Social and Environmental Medicine, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Benjaluck Phonrat
- Department of Clinical Tropical Medicine, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Sangchai Preutthipan
- Department of Obstetrics and Gynecology, Faculty of Medicine, Ramathibodi Hospital, Mahidol University, Bangkok, Thailand
| | - Rungsunn Tungtrongchitr
- Department of Tropical Nutrition and Food Science, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| |
Collapse
|
99
|
Jacobsen CM, Schwartz MA, Roberts HJ, Lim KE, Spevak L, Boskey AL, Zurakowski D, Robling AG, Warman ML. Enhanced Wnt signaling improves bone mass and strength, but not brittleness, in the Col1a1(+/mov13) mouse model of type I Osteogenesis Imperfecta. Bone 2016; 90:127-32. [PMID: 27297606 PMCID: PMC4985001 DOI: 10.1016/j.bone.2016.06.005] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/21/2015] [Revised: 05/30/2016] [Accepted: 06/04/2016] [Indexed: 11/24/2022]
Abstract
Osteogenesis Imperfecta (OI) comprises a group of genetic skeletal fragility disorders. The mildest form of OI, Osteogenesis Imperfecta type I, is frequently caused by haploinsufficiency mutations in COL1A1, the gene encoding the α1(I) chain of type 1 collagen. Children with OI type I have a 95-fold higher fracture rate compared to unaffected children. Therapies for OI type I in the pediatric population are limited to anti-catabolic agents. In adults with osteoporosis, anabolic therapies that enhance Wnt signaling in bone improve bone mass, and ongoing clinical trials are determining if these therapies also reduce fracture risk. We performed a proof-of-principle experiment in mice to determine whether enhancing Wnt signaling in bone could benefit children with OI type I. We crossed a mouse model of OI type I (Col1a1(+/Mov13)) with a high bone mass (HBM) mouse (Lrp5(+/p.A214V)) that has increased bone strength from enhanced Wnt signaling. Offspring that inherited the OI and HBM alleles had higher bone mass and strength than mice that inherited the OI allele alone. However, OI+HBM and OI mice still had bones with lower ductility compared to wild-type mice. We conclude that enhancing Wnt signaling does not make OI bone normal, but does improve bone properties that could reduce fracture risk. Therefore, agents that enhance Wnt signaling are likely to benefit children and adults with OI type 1.
Collapse
Affiliation(s)
- Christina M Jacobsen
- Orthopaedic Research Laboratories, Department of Orthopaedic Surgery, Boston Children's Hospital, Boston, MA, United States; Division of Endocrinology, Boston Children's Hospital, Boston, MA, United States; Division of Genetics, Boston Children's Hospital, Boston, MA, United States; Department of Pediatrics, Harvard Medical School, Boston, MA, United States.
| | - Marissa A Schwartz
- Orthopaedic Research Laboratories, Department of Orthopaedic Surgery, Boston Children's Hospital, Boston, MA, United States
| | - Heather J Roberts
- Orthopaedic Research Laboratories, Department of Orthopaedic Surgery, Boston Children's Hospital, Boston, MA, United States
| | - Kyung-Eun Lim
- Department of Anatomy and Cell Biology, Indiana University, Indianapolis, IN, United States
| | - Lyudmila Spevak
- Mineralized Tissues Laboratory, Hospital for Special Surgery, New York, NY, United States
| | - Adele L Boskey
- Mineralized Tissues Laboratory, Hospital for Special Surgery, New York, NY, United States; Weill Cornel Medical College, New York, NY, United States
| | - David Zurakowski
- Department of Anesthesia, Boston Children's Hospital, Boston, MA, United States
| | - Alexander G Robling
- Department of Anatomy and Cell Biology, Indiana University, Indianapolis, IN, United States
| | - Matthew L Warman
- Orthopaedic Research Laboratories, Department of Orthopaedic Surgery, Boston Children's Hospital, Boston, MA, United States; Department of Genetics, Harvard Medical School, Boston, MA, United States; Howard Hughes Medical Institute, Boston Children's Hospital, Boston, MA, United States
| |
Collapse
|
100
|
Hughes JM, Popp KL, Yanovich R, Bouxsein ML, Matheny RW. The role of adaptive bone formation in the etiology of stress fracture. Exp Biol Med (Maywood) 2016; 242:897-906. [PMID: 27496801 DOI: 10.1177/1535370216661646] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Stress fractures are common injuries with load-bearing activities. Stress fractures have been reported in the scientific literature for over a century; however, the etiology continues to be investigated with important distinctions made between the contributions of the tissue-level processes of bone remodeling and modeling. In response to novel repetitive loading, increased bone remodeling may serve to replace fatigue-damaged bone while at the same time creating temporary porosity. Much attention has been given to the role of remodeling in the etiology of stress fracture; however, the role of bone modeling has received less attention. Modest increases in modeling, via bone formation on the periosteal surface of long bones in response to mechanical loading, greatly increases the fatigue resistance of bone. Thus, enhancing this adaptive bone formation is a promising target for stress fracture prevention, and a focus on adaptive bone formation may reveal novel risk factors for stress fracture.
Collapse
Affiliation(s)
- Julie M Hughes
- 1 Military Performance Division, United States Army Research Institute of Environmental Medicine, Natick, MA 01760, USA
| | - Kristin L Popp
- 2 Endocrine Unit, Massachusetts General Hospital, Boston, MA 02114, USA
| | - Ran Yanovich
- 3 The Warrior Health Research Institute of Military Physiology, Israel Defense Forces' Medical Corps.,4 Heller Institute of Medical Research, Sheba Medical Center, Tel-Hashomer 52621, Israel
| | - Mary L Bouxsein
- 2 Endocrine Unit, Massachusetts General Hospital, Boston, MA 02114, USA.,5 Center for Advanced Orthopedic Studies, Beth Israel Deaconess Medical Center, Boston, MA 02215, USA.,6 Department of Orthopaedic Surgery, Harvard Medical School, Boston, MA 02215, USA
| | - Ronald W Matheny
- 1 Military Performance Division, United States Army Research Institute of Environmental Medicine, Natick, MA 01760, USA
| |
Collapse
|