1
|
Liu H, Liu L, Rosen CJ. PTH and the Regulation of Mesenchymal Cells within the Bone Marrow Niche. Cells 2024; 13:406. [PMID: 38474370 PMCID: PMC10930661 DOI: 10.3390/cells13050406] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2023] [Revised: 02/05/2024] [Accepted: 02/20/2024] [Indexed: 03/14/2024] Open
Abstract
Parathyroid hormone (PTH) plays a pivotal role in maintaining calcium homeostasis, largely by modulating bone remodeling processes. Its effects on bone are notably dependent on the duration and frequency of exposure. Specifically, PTH can initiate both bone formation and resorption, with the outcome being influenced by the manner of PTH administration: continuous or intermittent. In continuous administration, PTH tends to promote bone resorption, possibly by regulating certain genes within bone cells. Conversely, intermittent exposure generally favors bone formation, possibly through transient gene activation. PTH's role extends to various aspects of bone cell activity. It directly influences skeletal stem cells, osteoblastic lineage cells, osteocytes, and T cells, playing a critical role in bone generation. Simultaneously, it indirectly affects osteoclast precursor cells and osteoclasts, and has a direct impact on T cells, contributing to its role in bone resorption. Despite these insights, the intricate mechanisms through which PTH acts within the bone marrow niche are not entirely understood. This article reviews the dual roles of PTH-catabolic and anabolic-on bone cells, highlighting the cellular and molecular pathways involved in these processes. The complex interplay of these factors in bone remodeling underscores the need for further investigation to fully comprehend PTH's multifaceted influence on bone health.
Collapse
Affiliation(s)
- Hanghang Liu
- State Key Laboratory of Oral Diseases & National Center for Stomatology & National Clinical Research Center for Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu 610041, China;
- Maine Medical Center, MaineHealth Institute for Research, 81 Research Drive, Scarborough, ME 04074, USA;
| | - Linyi Liu
- Maine Medical Center, MaineHealth Institute for Research, 81 Research Drive, Scarborough, ME 04074, USA;
| | - Clifford J. Rosen
- Maine Medical Center, MaineHealth Institute for Research, 81 Research Drive, Scarborough, ME 04074, USA;
| |
Collapse
|
2
|
Li T, Yan Z, He S, Zhou C, Wang H, Yin X, Zou S, Duan P. Intermittent parathyroid hormone improves orthodontic retention via insulin-like growth factor-1. Oral Dis 2020; 27:290-300. [PMID: 32608117 DOI: 10.1111/odi.13519] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2020] [Revised: 05/06/2020] [Accepted: 06/18/2020] [Indexed: 12/29/2022]
Abstract
OBJECTIVES This study aimed to investigate the effects of intermittent parathyroid hormone (iPTH) on the stability of orthodontic retention and to explore the possible regulatory role of insulin-like growth factor-1 (IGF-1) in this process. METHODS Forty-eight 6-week-old male Wistar rats were adopted in this study. An orthodontic relapsing model was established to investigate the effects of iPTH on orthodontic retention. In vitro, an immortalized mouse cementoblast cell line OCCM-30 was detected by flow cytometry to study the effects of iPTH on cell proliferation and apoptosis. By application of a specific IGF-1 receptor inhibitor, the role of IGF-1 was also explored. RESULTS In vivo study found that daily injection of PTH significantly reduced the relapsing distance. Histological staining and ELISA assay showed faster periodontal regeneration during retention period in PTH group with increased RANKL/OPG ratio and greater amount of OCN, ALP, and IGF-1 in gingival cervical fluid (GCF). Cell experiment revealed that iPTH promoted proliferation and suppressed apoptosis of cementoblast. IGF-1 receptor inhibitor significantly restrained the anabolic effect of iPTH on OCCM-30 cells. CONCLUSIONS These findings suggest that iPTH could improve the stability of tooth movement by promoting periodontal regeneration. IGF-1 is essential in mediating the anabolic effects of iPTH.
Collapse
Affiliation(s)
- Tiancheng Li
- State Key Laboratory of Oral Diseases & National Clinical Research Center for Oral Diseases &, Department of Orthodontics, West China School & Hospital of Stomatology, Sichuan University, Chengdu, China
| | - Ziqi Yan
- Department of Stomatology, Xiangya Hospital, Central South University, Changsha, China
| | - Shushu He
- State Key Laboratory of Oral Diseases & National Clinical Research Center for Oral Diseases &, Department of Orthodontics, West China School & Hospital of Stomatology, Sichuan University, Chengdu, China
| | - Chenchen Zhou
- State Key Laboratory of Oral Diseases & National Clinical Research Center for Oral Diseases &, Department of Pediatric Dentistry, School & Hospital of Stomatology, Sichuan University, Chengdu, China
| | - Han Wang
- State Key Laboratory of Oral Diseases & National Clinical Research Center for Oral Diseases &, Department of Orthodontics, West China School & Hospital of Stomatology, Sichuan University, Chengdu, China
| | - Xing Yin
- State Key Laboratory of Oral Diseases & National Clinical Research Center for Oral Diseases &, Department of Orthodontics, West China School & Hospital of Stomatology, Sichuan University, Chengdu, China
| | - Shujuan Zou
- State Key Laboratory of Oral Diseases & National Clinical Research Center for Oral Diseases &, Department of Orthodontics, West China School & Hospital of Stomatology, Sichuan University, Chengdu, China
| | - Peipei Duan
- State Key Laboratory of Oral Diseases & National Clinical Research Center for Oral Diseases &, Department of Orthodontics, West China School & Hospital of Stomatology, Sichuan University, Chengdu, China
| |
Collapse
|
3
|
Arlt H, Mullarkey T, Hu D, Baron R, Ominsky MS, Mitlak B, Lanske B, Besschetnova T. Effects of abaloparatide and teriparatide on bone resorption and bone formation in female mice. Bone Rep 2020; 13:100291. [PMID: 32637467 PMCID: PMC7330158 DOI: 10.1016/j.bonr.2020.100291] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/12/2020] [Revised: 06/19/2020] [Accepted: 06/22/2020] [Indexed: 01/09/2023] Open
Abstract
Intermittent administration of PTH type 1 receptor (PTH1R) agonists increases bone remodeling, with greater stimulation of bone formation relative to bone resorption causing net gains in bone mass. This pharmacodynamic feature underlies the bone-building effects of teriparatide and abaloparatide, the only PTH1R agonists approved to reduce osteoporotic fracture risk in postmenopausal women. This study in 8-week-old female mice compared bone resorption and formation responses to these agents delivered at the same 10 μg/kg dose, and a 40 μg/kg abaloparatide dose was also included to reflect its 4-fold higher approved clinical dose. Peptides or vehicle were administered by daily supra-calvarial subcutaneous injection for 12 days, and local (calvarial) and systemic (L5 vertebral and tibial) responses were evaluated by histomorphometry. Terminal bone histomorphometry data indicated that calvarial resorption cavities were similar in both abaloparatide groups versus vehicle controls, whereas the teriparatide group had more calvarial resorption cavities compared with the vehicle or abaloparatide 40 μg/kg groups. The bone resorption marker serum CTX was significantly lower in the abaloparatide 40 μg/kg group and similar in the other two active treatment groups compared with vehicle controls. Both peptides increased trabecular bone formation rate (BFR) in L5 and proximal tibia versus vehicle, and L5 BFR was higher with abaloparatide 40 μg/kg versus teriparatide. At the tibial diaphysis, periosteal BFR was higher with abaloparatide 40 μg/kg versus vehicle or teriparatide, and endocortical BFR was higher with teriparatide but not with abaloparatide 10 or 40 μg/kg versus vehicle. Few differences in structural or microarchitectural bone parameters were observed with this brief duration of treatment. In summary, calvarial bone resorption cavity counts were higher in the teriparatide group versus the vehicle and abaloparatide 40 μg/kg groups, and the abaloparatide 40 μg/kg group had lower serum CTX versus vehicle. L5 and tibial trabecular bone formation indices were higher in all three active treatment groups versus vehicle. The abaloparatide 40 μg/kg group had higher L5 trabecular BFR and tibial periosteal BFR versus teriparatide, whereas tibial endocortical BFR was higher with teriparatide but not abaloparatide. Together, these findings in female mice indicate that an improved balance of bone formation versus bone resorption is established shortly after initiating treatment with abaloparatide. PTH receptor (PTH-R) agonists increase bone density by stimulating bone formation. PTH-R agonists differ in their propensity to increase bone resorption. Female mice were treated for 12 d with PTH-R agonists abaloparatide or teriparatide. The systemic resorption marker serum CTX was lower with abaloparatide vs vehicle. Calvarial resorption cavities were higher with teriparatide but not abaloparatide.
Collapse
Affiliation(s)
| | | | - Dorothy Hu
- Harvard School of Dental Medicine, Boston, MA, USA
| | - Roland Baron
- Harvard School of Dental Medicine, Boston, MA, USA.,Harvard Medical School, Boston, MA, USA.,Endocrine Unit, Massachusetts General Hospital, Boston, MA, USA
| | | | | | | | | |
Collapse
|
4
|
Ma L, Xiang L, Ma X, Zhang S, Gong P. Effects of αCGRP on the Adhesion, Proliferation and Differentiation of Osteoblasts Cultured on Titanium Surfaces. J HARD TISSUE BIOL 2020. [DOI: 10.2485/jhtb.29.205] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Affiliation(s)
- Li Ma
- Department of Vip center, School and Hospital of Stomatology, Cheeloo College of Medicine, Shandong University
- Shandong Provincial Key Laboratory of Oral Tissue Regeneration
- Shandong Engineering Laboratory for Dental Materials and Oral Tissue Regeneration
| | - Lin Xiang
- State Key Laboratory of Oral Diseases, West China Hospital of Stomatology, Sichuan University
- Department of Oral Implantology, West China Hospital of Stomatology, Sichuan University
| | - Xiaoni Ma
- Shandong Provincial Key Laboratory of Oral Tissue Regeneration
- Shandong Engineering Laboratory for Dental Materials and Oral Tissue Regeneration
- Department of Implantology, School and Hospital of Stomatology, Cheeloo College of Medicine, Shandong University
| | - Shuning Zhang
- Shandong Provincial Key Laboratory of Oral Tissue Regeneration
- Shandong Engineering Laboratory for Dental Materials and Oral Tissue Regeneration
| | - Ping Gong
- State Key Laboratory of Oral Diseases, West China Hospital of Stomatology, Sichuan University
- Department of Oral Implantology, West China Hospital of Stomatology, Sichuan University
| |
Collapse
|
5
|
Yukata K, Xie C, Li TF, Brown ML, Kanchiku T, Zhang X, Awad HA, Schwarz EM, Beck CA, Jonason JH, O'Keefe RJ. Teriparatide (human PTH 1-34) compensates for impaired fracture healing in COX-2 deficient mice. Bone 2018; 110:150-159. [PMID: 29408411 PMCID: PMC5878736 DOI: 10.1016/j.bone.2018.02.001] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/07/2017] [Revised: 02/01/2018] [Accepted: 02/02/2018] [Indexed: 01/08/2023]
Abstract
Genetic ablation of cyclooxygenase-2 (COX-2) in mice is known to impair fracture healing. To determine if teriparatide (human PTH1-34) can promote healing of Cox-2-deficient fractures, we performed detailed in vivo analyses using a murine stabilized tibia fracture model. Periosteal progenitor cell proliferation as well as bony callus formation was markedly reduced in Cox-2-/- mice at day 10 post-fracture. Remarkably, intermittent PTH1-34 administration increased proliferation of periosteal progenitor cells, restored callus formation on day 7, and enhanced bone formation on days 10, 14 and 21 in Cox-2-deficient mice. PTH1-34 also increased biomechanical torsional properties at days 10 or 14 in all genotypes, consistent with enhanced bony callus formation by radiologic examinations. To determine the effects of intermittent PTH1-34 for callus remodeling, TRAP staining was performed. Intermittent PTH1-34 treatment increased the number of TRAP positive cells per total callus area on day 21 in Cox-2-/- fractures. Taken together, the present findings indicate that intermittent PTH1-34 treatment could compensate for COX-2 deficiency and improve impaired fracture healing in Cox-2-deficient mice.
Collapse
Affiliation(s)
- Kiminori Yukata
- Center for Musculoskeletal Research, University of Rochester Medical Center, Rochester, NY, USA; Department of Orthopedic Surgery, Yamaguchi University Graduate School of Medicine, Ube, Yamaguchi, Japan
| | - Chao Xie
- Center for Musculoskeletal Research, University of Rochester Medical Center, Rochester, NY, USA
| | - Tian-Fang Li
- Center for Musculoskeletal Research, University of Rochester Medical Center, Rochester, NY, USA
| | - Matthew L Brown
- Center for Musculoskeletal Research, University of Rochester Medical Center, Rochester, NY, USA
| | - Tsukasa Kanchiku
- Department of Orthopedic Surgery, Yamaguchi University Graduate School of Medicine, Ube, Yamaguchi, Japan
| | - Xinping Zhang
- Center for Musculoskeletal Research, University of Rochester Medical Center, Rochester, NY, USA
| | - Hani A Awad
- Center for Musculoskeletal Research, University of Rochester Medical Center, Rochester, NY, USA
| | - Edward M Schwarz
- Center for Musculoskeletal Research, University of Rochester Medical Center, Rochester, NY, USA
| | - Christopher A Beck
- Department of Biostatistics and Computational Biology, University of Rochester Medical Center, Rochester, NY, USA
| | - Jennifer H Jonason
- Center for Musculoskeletal Research, University of Rochester Medical Center, Rochester, NY, USA
| | - Regis J O'Keefe
- Department of Orthopaedic Surgery, Washington University School of Medicine, St. Louis, MO, USA.
| |
Collapse
|
6
|
Yang Y, Blair HC, Shapiro IM, Wang B. The Proteasome Inhibitor Carfilzomib Suppresses Parathyroid Hormone-induced Osteoclastogenesis through a RANKL-mediated Signaling Pathway. J Biol Chem 2015; 290:16918-28. [PMID: 25979341 DOI: 10.1074/jbc.m115.663963] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2015] [Indexed: 12/17/2022] Open
Abstract
Parathyroid hormone (PTH) induces osteoclast formation and activity by increasing the ratio of RANKL/OPG in osteoblasts. The proteasome inhibitor carfilzomib (CFZ) has been used as an effective therapy for multiple myeloma via the inhibition of pathologic bone destruction. However, the effect of combination of PTH and CFZ on osteoclastogenesis is unknown. We now report that CFZ inhibits PTH-induced RANKL expression and secretion without affecting PTH inhibition of OPG expression, and it does so by blocking HDAC4 proteasomal degradation in osteoblasts. Furthermore, we used different types of culture systems, including co-culture, indirect co-culture, and transactivation, to assess the effect of CFZ on PTH action to induce osteoclastogenesis. Our results demonstrated that CFZ blocks PTH-induced osteoclast formation and bone resorption by its additional effect to inhibit RANKL-mediated IκB degradation and NF-κB activation in osteoclasts. This study showed for the first time that CFZ targets both osteoblasts and osteoclasts to suppress PTH-induced osteoclast differentiation and bone resorption. These findings warrant further investigation of this novel combination in animal models of osteoporosis and in patients.
Collapse
Affiliation(s)
- Yanmei Yang
- From the Center for Translational Medicine, Departments of Medicine and
| | - Harry C Blair
- the Department of Veterans Affairs Medical Center, Pittsburgh, Pennsylvania 15240, and Departments of Pathology and of Cell Biology, School of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania 15261
| | - Irving M Shapiro
- Orthopaedic Surgery, Sidney Kimmel Medical College, Thomas Jefferson University, Philadelphia, Pennsylvania 19107
| | - Bin Wang
- From the Center for Translational Medicine, Departments of Medicine and
| |
Collapse
|
7
|
Parathyroid hormone therapy mollifies radiation-induced biomechanical degradation in murine distraction osteogenesis. Plast Reconstr Surg 2013; 132:91e-100e. [PMID: 23806959 DOI: 10.1097/prs.0b013e3182910ae7] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
OBJECTIVE Descriptions of mandibular distraction osteogenesis for tissue replacement after oncologic resection or for defects caused by osteoradionecrosis have been limited. Previous work demonstrated radiation decreases union formation, cellularity and mineral density in mandibular distraction osteogenesis. The authors posit that intermittent systemic administration of parathyroid hormone will serve as a stimulant to cellular function, reversing radiation-induced damage and enhancing bone regeneration. METHODS Twenty male Lewis rats were randomly assigned to three groups: group 1 (radiation and distraction osteogenesis, n = 7) and group 2 (radiation, distraction osteogenesis, and parathyroid hormone, n = 5) received a human-equivalent dose of 35 Gy of radiation (human bioequivalent, 70 Gy) fractionated over 5 days. All groups, including group 3 (distraction osteogenesis, n = 8), underwent a left unilateral mandibular osteotomy with bilateral external fixator placement. Distraction osteogenesis was performed at a rate of 0.3 mm every 12 hours to reach a gap of 5.1 mm. Group 2 was injected with parathyroid hormone (60 µg/kg) subcutaneously daily for 3 weeks after the start of distraction osteogenesis. On postoperative day 40, all left hemimandibles were harvested. Biomechanical response parameters were generated. Statistical significance was considered at p ≤ 0.05. RESULTS Parathyroid hormone-treated mandibles had significantly higher failure load and higher yield than did untreated mandibles. However, these values were still significantly lower than those of nonirradiated mandibles. CONCLUSIONS The authors have successfully demonstrated the therapeutic efficacy of parathyroid hormone to stimulate and enhance bone regeneration in their irradiated murine mandibular model of distraction osteogenesis. Anabolic regimens of parathyroid hormone, a U.S. Food and Drug Administration-approved drug on formulary, significantly improve outcomes in a model of postoncologic craniofacial reconstruction.
Collapse
|
8
|
Wang B, Yang Y, Liu L, Blair HC, Friedman PA. NHERF1 regulation of PTH-dependent bimodal Pi transport in osteoblasts. Bone 2013; 52:268-77. [PMID: 23046970 PMCID: PMC3513631 DOI: 10.1016/j.bone.2012.10.001] [Citation(s) in RCA: 24] [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: 07/06/2012] [Revised: 09/18/2012] [Accepted: 10/01/2012] [Indexed: 02/01/2023]
Abstract
Control of systemic inorganic phosphate (Pi) levels is crucial for osteoid mineralization. Parathyroid hormone (PTH) mediates actions on phosphate homeostasis mostly by regulating the activity of the type 2 sodium-phosphate cotransporter (Npt2), and this action requires the PDZ protein NHERF1. Osteoblasts express Npt2 and in response to PTH enhance osteogenesis by increasing mineralized matrix. The regulation of Pi transport in osteoblasts is poorly understood. To address this gap we characterized PTH-dependent Pi transport and the role of NHERF1 in primary mouse calvarial osteoblasts. Under proliferating conditions osteoblasts express Npt2a, Npt2b, PTH receptor, and NHERF1. Npt2a mRNA expression was lower in calvarial osteoblasts from NHERF1-null mice. Under basal conditions Pi uptake in osteoblasts from wild-type mice was greater than that of knockout mice. PTH inhibited Pi uptake in proliferating osteoblasts from wild-type mice, but not in cells from knockout mice. In vitro induction of mineralization enhanced osteoblast differentiation and increased osterix and osteocalcin expression. Contrary to the results with proliferating osteoblasts, PTH increased Pi uptake and ATP secretion in differentiated osteoblasts from wild-type mice. PTH had no effect on Pi uptake or ATP release in differentiated osteoblasts from knockout mice. NHERF1 regulation of PTH-sensitive Pi uptake in proliferating osteoblasts is mediated by cAMP/PKA and PLC/PKC, while modulation of Pi uptake in differentiated osteoblasts depends only on cAMP/PKA signaling. The results suggest that NHERF1 cooperates with PTH in differentiated osteoblasts to increase matrix mineralization. We conclude that NHERF1 regulates PTH that differentially affects Na-dependent Pi transport at distinct stages of osteoblast proliferation and maturation.
Collapse
Affiliation(s)
- Bin Wang
- Laboratory for G Protein-Coupled Receptor Biology, Department of Pharmacology & Chemical Biology, Pittsburgh, PA, USA
| | - Yanmei Yang
- Laboratory for G Protein-Coupled Receptor Biology, Department of Pharmacology & Chemical Biology, Pittsburgh, PA, USA
| | - Li Liu
- Pittsburgh Veterans Affairs Medical Center and Department of Pathology, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
| | - Harry C. Blair
- Pittsburgh Veterans Affairs Medical Center and Department of Pathology, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
| | - Peter A. Friedman
- Laboratory for G Protein-Coupled Receptor Biology, Department of Pharmacology & Chemical Biology, Pittsburgh, PA, USA
| |
Collapse
|
9
|
Zhu J, Siclari VA, Liu F, Spatz JM, Chandra A, Divieti Pajevic P, Qin L. Amphiregulin-EGFR signaling mediates the migration of bone marrow mesenchymal progenitors toward PTH-stimulated osteoblasts and osteocytes. PLoS One 2012; 7:e50099. [PMID: 23300521 PMCID: PMC3534030 DOI: 10.1371/journal.pone.0050099] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2012] [Accepted: 10/16/2012] [Indexed: 12/31/2022] Open
Abstract
Intermittent administration of parathyroid hormone (PTH) dramatically increases bone mass and currently is one of the most effective treatments for osteoporosis. However, the detailed mechanisms are still largely unknown. Here we demonstrate that conditioned media from PTH-treated osteoblastic and osteocytic cells contain soluble chemotactic factors for bone marrow mesenchymal progenitors, which express a low amount of PTH receptor (PTH1R) and do not respond to PTH stimulation by increasing cAMP production or migrating toward PTH alone. Conditioned media from PTH-treated osteoblasts elevated phosphorylated Akt and p38MAPK amounts in mesenchymal progenitors and inhibition of these pathways blocked the migration of these progenitors toward conditioned media. Our previous and current studies revealed that PTH stimulates the expression of amphiregulin, an epidermal growth factor (EGF)-like ligand that signals through the EGF receptor (EGFR), in both osteoblasts and osteocytes. Interestingly, conditioned media from PTH-treated osteoblasts increased EGFR phosphorylation in mesenchymal progenitors. Using several different approaches, including inhibitor, neutralizing antibody, and siRNA, we demonstrate that PTH increases the release of amphiregulin from osteoblastic cells, which acts on the EGFRs expressed on mesenchymal progenitors to stimulate the Akt and p38MAPK pathways and subsequently promote their migration in vitro. Furthermore, inactivation of EGFR signaling specifically in osteoprogenitors/osteoblasts attenuated the anabolic actions of PTH on bone formation. Taken together, these results suggest a novel mechanism for the therapeutic effect of PTH on osteoporosis and an important role of EGFR signaling in mediating PTH's anabolic actions on bone.
Collapse
Affiliation(s)
- Ji Zhu
- McKay Orthopaedic Research Laboratory, Department of Orthopaedic Surgery, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
| | - Valerie A. Siclari
- McKay Orthopaedic Research Laboratory, Department of Orthopaedic Surgery, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
| | - Fei Liu
- McKay Orthopaedic Research Laboratory, Department of Orthopaedic Surgery, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
- Department of Plastic and Reconstructive Surgery, Shanghai Ninth People's Hospital, Shanghai, China
| | - Jordan M. Spatz
- Endocrine Unit, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts, United States of America
| | - Abhishek Chandra
- McKay Orthopaedic Research Laboratory, Department of Orthopaedic Surgery, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
| | - Paola Divieti Pajevic
- Endocrine Unit, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts, United States of America
| | - Ling Qin
- McKay Orthopaedic Research Laboratory, Department of Orthopaedic Surgery, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
- * E-mail:
| |
Collapse
|
10
|
D'Amelio P, Tamone C, Sassi F, D'Amico L, Roato I, Patanè S, Ravazzoli M, Veneziano L, Ferracini R, Pescarmona GP, Isaia GC. Teriparatide increases the maturation of circulating osteoblast precursors. Osteoporos Int 2012; 23:1245-53. [PMID: 21617993 DOI: 10.1007/s00198-011-1666-2] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/01/2011] [Accepted: 04/19/2011] [Indexed: 12/14/2022]
Abstract
UNLABELLED This study shows that teriparatide promotes the circulating osteoblast (OB) precursor degree of maturation in patients affected by postmenopausal osteoporosis. INTRODUCTION Anabolic treatment with teriparatide has proven effective for the therapy of postmenopausal osteoporosis and significantly reduces the risk of non-vertebral fragility fractures. The aim of this study was to investigate the effect of teriparatide on circulating OB precursors. METHODS We evaluated by flow cytometry and real-time PCR the expression of OBs typical markers in peripheral blood mononuclear cells during treatment with teriparatide plus calcium and vitamin D, raloxifene plus calcium and vitamin D or calcium and vitamin D alone at various time points. Serum bone alkaline phosphatase and osteocalcin (OC) were measured as markers of bone turnover. RESULTS Our results show that circulating OB precursors are more numerous and more immature in patients affected by fragility fractures than in osteoporotic patients without fractures. We also show that teriparatide treatment increases the expression of alkaline phosphatase and of OC in OB precursors; thus, it increases their degree of maturation. CONCLUSIONS We suggest that teriparatide acts as anabolic agents also by promoting the maturation of OB precursors.
Collapse
Affiliation(s)
- P D'Amelio
- Department of Surgical and Medical Disciplines Gerontology Section, University of Torino-Italy, Corso Bramante 88/90, 10126 Torino, Italy.
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
11
|
Geng S, Zhou S, Glowacki J. Age-related decline in osteoblastogenesis and 1α-hydroxylase/CYP27B1 in human mesenchymal stem cells: stimulation by parathyroid hormone. Aging Cell 2011; 10:962-71. [PMID: 21824271 DOI: 10.1111/j.1474-9726.2011.00735.x] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
With aging, there is a decline in bone mass and in osteoblast differentiation of human mesenchymal stem cells (hMSCs) in vitro. Osteoblastogenesis can be stimulated with 1,25-dihydroxyvitamin D(3) [1,25(OH)(2) D(3) ] and, in some hMSCs, by the precursor 25-hydroxyvitamin D(3) (25OHD(3) ). CYP27B1/1α-hydroxylase activates 25OHD(3) and, to a variable degree, hMSCs express CYP27B1. In this study, we tested the hypotheses (i) that age affects responsiveness to 25OHD(3) and expression/activity of CYP27B1 in hMSCs and (ii) that parathyroid hormone (PTH) upregulates CYP27B1 in hMSCs, as it does in renal cells. There were age-related declines in osteoblastogenesis (n=8, P=0.0286) and in CYP27B1 gene expression (n=27, r= -0.498; P=0.008) in hMSCs. Unlike hMSCs from young subjects (≤50 years), hMSCs from older subjects (≥55 years) were resistant to 25OHD(3) stimulation of osteoblastogenesis. PTH1-34 (100 nm) provided hMSCs with responsiveness to 25OHD(3) (P=0.0313, Wilcoxon matched pairs test) and with two episodes of increased 1,25(OH)(2) D(3) synthesis, of cAMP response element binding protein (CREB) activation, and of CYP27B1 upregulation. Both increases in CYP27B1 expression by PTH were obliterated by CREB-siRNA or KG-501 (which specifically inhibits the downstream binding of activated CREB). Only the second period of CREB signaling was diminished by AG1024, an inhibitor of insulin-like growth factor-I receptor kinase. Thus, PTH stimulated hMSCs from elders with responsiveness to 25OHD(3) by upregulating expression/activity of CYP27B1 and did so through CREB and IGF-I pathways.
Collapse
Affiliation(s)
- Shuo Geng
- Department of Orthopedic Surgery, Brigham and Women's Hospital, Harvard Medical School, 75 Francis Street, Boston, MA 02115, USA
| | | | | |
Collapse
|
12
|
Ogata N, Shinoda Y, Wettschureck N, Offermanns S, Takeda S, Nakamura K, Segre GV, Chung UI, Kawaguchi H. G alpha(q) signal in osteoblasts is inhibitory to the osteoanabolic action of parathyroid hormone. J Biol Chem 2011; 286:13733-40. [PMID: 21345793 DOI: 10.1074/jbc.m110.200196] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
This study examined the role of the Gα(q) signal constituted by Gα(q) and Gα(11) (encoded by Gnα(q) and Gnα(11), respectively), a major intracellular pathway of parathyroid hormone (PTH), in the PTH osteoanabolic action by the gain- and loss-of-function analyses. Transgenic mice with osteoblast-specific overexpression of the constitutively active Gnα(q) gene under the control of 2.3-kb type I collagen α1 chain (Col1a1) promoter exhibited osteopenia with decreased bone formation parameters and did not respond to the daily PTH treatment. We then established osteoblast-specific Gnα(q) and Gnα(11) double-knock-out (cDKO) mice by crossing the 2.3-kb Col1a1 promoter-Cre recombinase transgenic mice and those with Gnα(q) gene flanked with loxP and global ablation of Gnα(11) (Col1a1-Cre(+/-);Gna(q)(fl/fl);Gna(11)(-/-)) and found that the cDKO and single knock-out littermates of Gnα(q) or Gnα(11) exhibited normal bone volume and turnover under physiological conditions. With a daily injection of PTH, however, the cDKO mice, but not the single knock-out mice, showed higher bone volume and turnover than the wild-type littermates. Cultures of primary osteoblasts derived from cDKO and wild-type littermates confirmed enhancement of the PTH osteoanabolic action by the Gα(q) signal deficiency in a cell-autonomous mechanism, in association with the membrane translocation of protein kinase Cδ. This enhancement was reproduced by overexpression of regulator of G protein signaling-2, a Gα(q) signal inhibitor, in osteoblastic MC3T3-E1 cells. Hence, the Gα(q) signal plays an inhibitory role in the PTH osteoanabolic action, suggesting that its suppression may lead to a novel treatment in combination with PTH against osteoporosis.
Collapse
Affiliation(s)
- Naoshi Ogata
- Department of Bone and Cartilage Regenerative Medicine, University of Tokyo, Tokyo 113-8655, Japan
| | | | | | | | | | | | | | | | | |
Collapse
|