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Pereda A, Elli FM, Thiele S, de Sanctis L, Rothenbuhler A, Hanna P, Francou B, Ertl DA, Perez de Nanclares G, Linglart A, Mantovani G. Inactivating PTH/PTHrP signaling disorders (iPPSDs): evaluation of the new classification in a multicenter large series of 544 molecularly characterized patients. Eur J Endocrinol 2021; 184:311-320. [PMID: 33270042 DOI: 10.1530/eje-20-0625] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/05/2020] [Accepted: 11/30/2020] [Indexed: 11/08/2022]
Abstract
OBJECTIVE Pseudohypoparathyroidism and related disorders belong to a group of heterogeneous rare diseases that share an impaired signaling downstream of Gsα-protein-coupled receptors. Affected patients may present with various combination of symptoms including resistance to PTH and/or to other hormones, ectopic ossifications, brachydactyly type E, early onset obesity, short stature and cognitive difficulties. Several years ago we proposed a novel nomenclature under the term of inactivating PTH/PTHrP signaling disorders (iPPSD). It is now of utmost importance to validate these criteria and/or improve the basis of this new classification. DESIGN Retrospective study of a large international series of 459 probands and 85 relatives molecularly characterized. METHODS Information on major and minor criteria associated with iPPSD and genetic results were retrieved from patient files. We compared the presence of each criteria according to the iPPSD subtype, age and gender of the patients. RESULTS More than 98% of the probands met the proposed criteria for iPPSD classification. Noteworthy, most patients (85%) presented a combination of symptoms rather than a single sign suggestive of iPPSD and the overlap among the different genetic forms of iPPSD was confirmed. The clinical and molecular characterization of relatives identified familial history as an additional important criterion predictive of the disease. CONCLUSIONS The phenotypic analysis of this large cohort confirmed the utility of the major and minor criteria and their combination to diagnose iPPSD. This report shows the importance of having simple and easily recognizable signs to diagnose with confidence these rare disorders and supports a better management of patients.
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Affiliation(s)
- Arrate Pereda
- Molecular (Epi)Genetics Laboratory, BioAraba Research Health Institute, Hospital Universitario Araba-Txagorritxu, Vitoria-Gasteiz, Alava, Spain
| | - Francesca M Elli
- Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, Endocrinology Unit, Milan, Italy
- Department of Clinical Sciences and Community Health, University of Milan, Milan, Italy
| | - Suzanne Thiele
- Department of Pediatrics, University of Lübeck, Lübeck, Germany
| | - Luisa de Sanctis
- Department of Public Health and Pediatric Sciences, University of Torino, Regina Margherita Children's Hospital-AOU Città della Salute e della Scienza, Torino, Italy
| | - Anya Rothenbuhler
- AP-HP, Service d'endocrinologie et diabète de l'enfant et Centre de référence des maladies rares du métabolisme du calcium et du phosphate, filière OSCAR, EndoRare and BOND ERN, Hôpital de Bicêtre, Le Kremlin-Bicêtre, France
| | - Patrick Hanna
- Université Paris-Saclay, Hôpital de Bicêtre, INSERM U1185, Le Kremlin-Bicêtre, France
| | - Bruno Francou
- Université Paris-Saclay, Hôpital de Bicêtre, INSERM U1185, Le Kremlin-Bicêtre, France
- AP-HP, Service de génétique moléculaire, Hôpital de Bicêtre, Le Kremlin-Bicêtre, France
| | - Diana Alexandra Ertl
- University Clinic of Paediatrics and Adolescent Medicine, Medical University of Vienna, Vienna, Austria
| | - Guiomar Perez de Nanclares
- Molecular (Epi)Genetics Laboratory, BioAraba Research Health Institute, Hospital Universitario Araba-Txagorritxu, Vitoria-Gasteiz, Alava, Spain
| | - Agnès Linglart
- AP-HP, Service d'endocrinologie et diabète de l'enfant et Centre de référence des maladies rares du métabolisme du calcium et du phosphate, filière OSCAR, EndoRare and BOND ERN, Hôpital de Bicêtre, Le Kremlin-Bicêtre, France
- Université Paris-Saclay, Hôpital de Bicêtre, INSERM U1185, Le Kremlin-Bicêtre, France
| | - Giovanna Mantovani
- Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, Endocrinology Unit, Milan, Italy
- Department of Clinical Sciences and Community Health, University of Milan, Milan, Italy
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Yan B, Zhang Z, Jin D, Cai C, Jia C, Liu W, Wang T, Li S, Zhang H, Huang B, Lai P, Wang H, Liu A, Zeng C, Cai D, Jiang Y, Bai X. mTORC1 regulates PTHrP to coordinate chondrocyte growth, proliferation and differentiation. Nat Commun 2016; 7:11151. [PMID: 27039827 PMCID: PMC4822018 DOI: 10.1038/ncomms11151] [Citation(s) in RCA: 87] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2016] [Accepted: 02/24/2016] [Indexed: 12/20/2022] Open
Abstract
Precise coordination of cell growth, proliferation and differentiation is essential for the development of multicellular organisms. Here, we report that although the mechanistic target of rapamycin complex 1 (mTORC1) activity is required for chondrocyte growth and proliferation, its inactivation is essential for chondrocyte differentiation. Hyperactivation of mTORC1 via TSC1 gene deletion in chondrocytes causes uncoupling of the normal proliferation and differentiation programme within the growth plate, resulting in uncontrolled cell proliferation, and blockage of differentiation and chondrodysplasia in mice. Rapamycin promotes chondrocyte differentiation and restores these defects in mutant mice. Mechanistically, mTORC1 downstream kinase S6K1 interacts with and phosphorylates Gli2, and releases Gli2 from SuFu binding, resulting in nuclear translocation of Gli2 and transcription of parathyroid hormone-related peptide (PTHrP), a key regulator of bone development. Our findings demonstrate that dynamically controlled mTORC1 activity is crucial to coordinate chondrocyte proliferation and differentiation partially through regulating Gli2/PTHrP during endochondral bone development.
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Affiliation(s)
- Bo Yan
- Academy of Orthopedics, Guangdong Province, The Third Affiliated Hospital, Southern Medical University, Guangzhou 510630, China
| | - Zhongmin Zhang
- Academy of Orthopedics, Guangdong Province, The Third Affiliated Hospital, Southern Medical University, Guangzhou 510630, China
| | - Dadi Jin
- Academy of Orthopedics, Guangdong Province, The Third Affiliated Hospital, Southern Medical University, Guangzhou 510630, China
| | - Chen Cai
- Department of Orthopedics, Zhujiang Hospital, Southern Medical University, Guangzhou 510282, China
| | - Chunhong Jia
- State Key Laboratory of Organ Failure Research, Department of Cell Biology, School of Basic Medical Sciences, Southern Medical University, Guangzhou 510515, China
| | - Wen Liu
- State Key Laboratory of Organ Failure Research, Department of Cell Biology, School of Basic Medical Sciences, Southern Medical University, Guangzhou 510515, China
| | - Ting Wang
- State Key Laboratory of Organ Failure Research, Department of Cell Biology, School of Basic Medical Sciences, Southern Medical University, Guangzhou 510515, China
| | - Shengfa Li
- Academy of Orthopedics, Guangdong Province, The Third Affiliated Hospital, Southern Medical University, Guangzhou 510630, China
| | - Haiyan Zhang
- Academy of Orthopedics, Guangdong Province, The Third Affiliated Hospital, Southern Medical University, Guangzhou 510630, China
| | - Bin Huang
- Academy of Orthopedics, Guangdong Province, The Third Affiliated Hospital, Southern Medical University, Guangzhou 510630, China
| | - Pinglin Lai
- Academy of Orthopedics, Guangdong Province, The Third Affiliated Hospital, Southern Medical University, Guangzhou 510630, China
- State Key Laboratory of Organ Failure Research, Department of Cell Biology, School of Basic Medical Sciences, Southern Medical University, Guangzhou 510515, China
| | - Hua Wang
- Academy of Orthopedics, Guangdong Province, The Third Affiliated Hospital, Southern Medical University, Guangzhou 510630, China
- State Key Laboratory of Organ Failure Research, Department of Cell Biology, School of Basic Medical Sciences, Southern Medical University, Guangzhou 510515, China
| | - Anling Liu
- State Key Laboratory of Organ Failure Research, Department of Cell Biology, School of Basic Medical Sciences, Southern Medical University, Guangzhou 510515, China
| | - Chun Zeng
- Academy of Orthopedics, Guangdong Province, The Third Affiliated Hospital, Southern Medical University, Guangzhou 510630, China
| | - Daozhang Cai
- Academy of Orthopedics, Guangdong Province, The Third Affiliated Hospital, Southern Medical University, Guangzhou 510630, China
| | - Yu Jiang
- Department of Pharmacology and Chemical Biology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania 15213, USA
| | - Xiaochun Bai
- Academy of Orthopedics, Guangdong Province, The Third Affiliated Hospital, Southern Medical University, Guangzhou 510630, China
- State Key Laboratory of Organ Failure Research, Department of Cell Biology, School of Basic Medical Sciences, Southern Medical University, Guangzhou 510515, China
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Ohta Y, Okabe T, Larmour C, Di Rocco A, Maijenburg M, Phillips A, Speck NA, Wakitani S, Nakamura T, Yamada Y, Enomoto-Iwamoto M, Pacifici M, Iwamoto M. Articular cartilage endurance and resistance to osteoarthritic changes require transcription factor Erg. Arthritis Rheumatol 2015; 67:2679-90. [PMID: 26097038 PMCID: PMC5568074 DOI: 10.1002/art.39243] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2014] [Accepted: 06/09/2015] [Indexed: 11/10/2022]
Abstract
OBJECTIVE To determine whether and how the transcription factor Erg participates in the genesis, establishment, and maintenance of articular cartilage. METHODS Floxed Erg mice were mated with Gdf5-Cre mice to generate conditional mutants lacking Erg in their joints. Joints of mutant and control mice were subjected to morphologic and molecular characterization and also to experimental surgically induced osteoarthritis (OA). Gene expression, promoter reporter assays, and gain- and loss-of-function in vitro tests were used to characterize molecular mechanisms of Erg action. RESULTS Conditional Erg ablation did not elicit obvious changes in limb joint development and overall phenotype in juvenile mice. However, as mice aged, joints of mutant mice degenerated spontaneously and exhibited clear OA-like phenotypic defects. Joints in juvenile mutant mice were more sensitive to surgically induced OA and became defective sooner than operated joints in control mice. Global gene expression data and other studies identified parathyroid hormone-related protein (PTHrP) and lubricin as possible downstream effectors and mediators of Erg action in articular chondrocytes. Reporter assays using control and mutated promoter-enhancer constructs indicated that Erg acted on Ets DNA binding sites to stimulate PTHrP expression. Erg was up-regulated in severely affected areas in human OA articular cartilage but remained barely appreciable in areas of less affected cartilage. CONCLUSION The study shows for the first time that Erg is a critical molecular regulator of the endurance of articular cartilage during postnatal life and that Erg can mitigate spontaneous and experimental OA. Erg appears to do this through regulating expression of PTHrP and lubricin, factors known for their protective roles in joints.
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Affiliation(s)
- Yoichi Ohta
- Translational Research Program in Pediatric Orthopaedics, The Children's Hospital of Philadelphia Division of Orthopaedic Surgery, Philadelphia, PA 19104
- Department of Orthopaedic Surgery, Osaka City University Graduate School of Medicine, Osaka 565-0871, Japan
| | - Takahiro Okabe
- Department of Orthopedics, Itabashi Chuo General Hospital, Tokyo 173-8606, Japan
| | - Colleen Larmour
- Translational Research Program in Pediatric Orthopaedics, The Children's Hospital of Philadelphia Division of Orthopaedic Surgery, Philadelphia, PA 19104
| | - Agnese Di Rocco
- Translational Research Program in Pediatric Orthopaedics, The Children's Hospital of Philadelphia Division of Orthopaedic Surgery, Philadelphia, PA 19104
| | - Marijke Maijenburg
- Department of Cell and Developmental Biology, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA 19104
| | - Amanda Phillips
- Department of Cell and Developmental Biology, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA 19104
| | - Nancy A. Speck
- Department of Cell and Developmental Biology, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA 19104
| | - Shigeyuki Wakitani
- Department of Artificial Joint and Biomaterials, Hiroshima University Graduate School of Biomedical Sciences, Hiroshima 734-8551, Japan
| | - Takashi Nakamura
- Oral Health and Development Science, Tohoku University Graduate school of Dentistry, Sendai 980-0826, Japan
| | - Yoshihiko Yamada
- National Institute of Dental and Craniofacial Research, NIH, MD 20892
| | - Motomi Enomoto-Iwamoto
- Translational Research Program in Pediatric Orthopaedics, The Children's Hospital of Philadelphia Division of Orthopaedic Surgery, Philadelphia, PA 19104
| | - Maurizio Pacifici
- Translational Research Program in Pediatric Orthopaedics, The Children's Hospital of Philadelphia Division of Orthopaedic Surgery, Philadelphia, PA 19104
| | - Masahiro Iwamoto
- Translational Research Program in Pediatric Orthopaedics, The Children's Hospital of Philadelphia Division of Orthopaedic Surgery, Philadelphia, PA 19104
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Hirai T, Kobayashi T, Nishimori S, Karaplis AC, Goltzman D, Kronenberg HM. Bone Is a Major Target of PTH/PTHrP Receptor Signaling in Regulation of Fetal Blood Calcium Homeostasis. Endocrinology 2015; 156:2774-80. [PMID: 26052897 PMCID: PMC4511135 DOI: 10.1210/en.2014-1835] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
The blood calcium concentration during fetal life is tightly regulated within a narrow range by highly interactive homeostatic mechanisms that include transport of calcium across the placenta and fluxes in and out of bone; the mechanisms of this regulation are poorly understood. Our findings that endochondral bone-specific PTH/PTHrP receptor (PPR) knockout (KO) mice showed significant reduction of fetal blood calcium concentration compared with that of control littermates at embryonic day 18.5 led us to focus on bone as a possibly major determinant of fetal calcium homeostasis. We found that the fetal calcium concentration of Runx2 KO mice was significantly higher than that of control littermates, suggesting that calcium flux into bone had a considerable influence on the circulating calcium concentration. Moreover, Runx2:PTH double mutant fetuses showed calcium levels similar to those of Runx2 KO mice, suggesting that part of the fetal hypocalcemia in PTH KO mice was caused by the increment of the mineralized bone mass allowed by the formation of osteoblasts. Finally, Rank:PTH double mutant mice had a blood calcium concentration even lower than that of the either Rank KO or PTH KO mice alone at embryonic day 18.5. These observations in our genetic models suggest that PTH/PTHrP receptor signaling in bones has a significant role of the regulation of fetal blood calcium concentration and that both placental transport and osteoclast activation contribute to PTH's hypercalcemic action. They also show that PTH-independent deposition of calcium in bone is the major controller of fetal blood calcium level.
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Affiliation(s)
- Takao Hirai
- Endocrine Unit (T.H., T.K., S.N., H.M.K.), Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts; Sir Mortimer B. Davis Jewish General Hospital (A.C.K.), McGill University, Montreal, Québec, Canada H3T 1E2; and Royal Victoria Hospital of the McGill University Health Centre (D.G.), Montreal, Québec, Canada H3A 1A1
| | - Tatsuya Kobayashi
- Endocrine Unit (T.H., T.K., S.N., H.M.K.), Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts; Sir Mortimer B. Davis Jewish General Hospital (A.C.K.), McGill University, Montreal, Québec, Canada H3T 1E2; and Royal Victoria Hospital of the McGill University Health Centre (D.G.), Montreal, Québec, Canada H3A 1A1
| | - Shigeki Nishimori
- Endocrine Unit (T.H., T.K., S.N., H.M.K.), Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts; Sir Mortimer B. Davis Jewish General Hospital (A.C.K.), McGill University, Montreal, Québec, Canada H3T 1E2; and Royal Victoria Hospital of the McGill University Health Centre (D.G.), Montreal, Québec, Canada H3A 1A1
| | - Andrew C Karaplis
- Endocrine Unit (T.H., T.K., S.N., H.M.K.), Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts; Sir Mortimer B. Davis Jewish General Hospital (A.C.K.), McGill University, Montreal, Québec, Canada H3T 1E2; and Royal Victoria Hospital of the McGill University Health Centre (D.G.), Montreal, Québec, Canada H3A 1A1
| | - David Goltzman
- Endocrine Unit (T.H., T.K., S.N., H.M.K.), Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts; Sir Mortimer B. Davis Jewish General Hospital (A.C.K.), McGill University, Montreal, Québec, Canada H3T 1E2; and Royal Victoria Hospital of the McGill University Health Centre (D.G.), Montreal, Québec, Canada H3A 1A1
| | - Henry M Kronenberg
- Endocrine Unit (T.H., T.K., S.N., H.M.K.), Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts; Sir Mortimer B. Davis Jewish General Hospital (A.C.K.), McGill University, Montreal, Québec, Canada H3T 1E2; and Royal Victoria Hospital of the McGill University Health Centre (D.G.), Montreal, Québec, Canada H3A 1A1
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Jahan E, Matsumoto A, Rafiq AM, Hashimoto R, Inoue T, Udagawa J, Sekine J, Otani H. Fetal jaw movement affects Ihh signaling in mandibular condylar cartilage development: the possible role of Ihh as mechanotransduction mediator. Arch Oral Biol 2014; 59:1108-18. [PMID: 25033382 DOI: 10.1016/j.archoralbio.2014.06.009] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2013] [Revised: 06/12/2014] [Accepted: 06/22/2014] [Indexed: 02/06/2023]
Abstract
OBJECTIVE Jaw movement is an important mechanical factor for prenatal development of the condylar cartilage of mandible. Fetal jaw movement restriction has been shown to cause deformity of the mandibular condyle. We hypothesized that this treatment affects the expression of mechanosensitive molecules, namely Indian hedgehog (Ihh) and Parathyroid hormone related protein (PTHrP) in the condyle. EXPERIMENTAL METHODS We restrained jaw movement by suturing the jaw of E15.5 mouse embryos and allowed them to develop until E18.5 using exo utero system, and analyzed them by immunohistochemistry and in situ hybridization methods. RESULTS Morphological, histomorphometric and immunohistochemical study showed that the mandibular condylar cartilage was reduced and deformed, the volume and total cell numbers in the condylar cartilage were also reduced, and number and/or distribution of 5-bromo-2'-deoxyuridine-positive cells, Ihh-positive cells in the mesenchymal and pre-hypertrophic zones were significantly and correspondingly decreased in the sutured group. Using in situ hybridization, reduced expression of Ihh, PTHrP and their related receptors were observed in condylar cartilage of the sutured embryos. CONCLUSIONS Our results revealed that the altered mechanical stress induced by prenatal jaw movement restriction decreased proliferating cells, the amount of cartilage, and altered expression of the Ihh and PTHrP, suggesting that Ihh act as mechanotransduction mediators in the development of mandibular condylar cartilage.
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Affiliation(s)
- Esrat Jahan
- Department of Developmental Biology, Faculty of Medicine, Shimane University, 89-1 Enya-cho, Izumo, Shimane 693-8501, Japan.
| | - Akihiro Matsumoto
- Department of Developmental Biology, Faculty of Medicine, Shimane University, 89-1 Enya-cho, Izumo, Shimane 693-8501, Japan
| | - Ashiq Mahmood Rafiq
- Department of Developmental Biology, Faculty of Medicine, Shimane University, 89-1 Enya-cho, Izumo, Shimane 693-8501, Japan
| | - Ryuju Hashimoto
- Department of Clinical Nursing, Faculty of Medicine, Shimane University, 89-1 Enya-cho, Izumo, Shimane 693-8501, Japan
| | - Takayuki Inoue
- Department of Developmental Biology, Faculty of Medicine, Shimane University, 89-1 Enya-cho, Izumo, Shimane 693-8501, Japan
| | - Jun Udagawa
- Division of Anatomy and Cell Biology, Department of Anatomy, Shiga University of Medical Science, Seta Tsukinowa-cho, Otsu, Shiga 520-2192, Japan
| | - Joji Sekine
- Department of Oral & Maxillofacial Surgery, Faculty of Medicine, Shimane University, 89-1 Enya-cho, Izumo, Shimane 693-8501, Japan
| | - Hiroki Otani
- Department of Developmental Biology, Faculty of Medicine, Shimane University, 89-1 Enya-cho, Izumo, Shimane 693-8501, Japan
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Inoue D. [Role for PTHrP in bone and cartilage metabolism]. Clin Calcium 2014; 24:863-869. [PMID: 24870837] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
PTH-related peptide (PTHrP) is a widely distributed cytokine, which shares the cognate receptor PTHR1 with PTH. Originally identified as a causal factor of humoral hypercalcemia of malignancy twenty years ago, PTHrP is now recognized as a critical physiological regulator of various biological processes, including bone and cartilage metabolism.
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Affiliation(s)
- Daisuke Inoue
- Third Department of Medicine, Teikyo University Chiba Medical Center, Japan
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7
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Ongkeko WM, Burton D, Kiang A, Abhold E, Kuo SZ, Rahimy E, Yang M, Hoffman RM, Wang-Rodriguez J, Deftos LJ. Parathyroid hormone related-protein promotes epithelial-to-mesenchymal transition in prostate cancer. PLoS One 2014; 9:e85803. [PMID: 24465715 PMCID: PMC3899059 DOI: 10.1371/journal.pone.0085803] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2013] [Accepted: 12/02/2013] [Indexed: 12/21/2022] Open
Abstract
Parathyroid hormone-related protein (PTHrP) possesses a variety of physiological and developmental functions and is also known to facilitate the progression of many common cancers, notably their skeletal invasion, primarily by increasing bone resorption. The purpose of this study was to determine whether PTHrP could promote epithelial-to-mesenchymal transition (EMT), a process implicated in cancer stem cells that is critically involved in cancer invasion and metastasis. EMT was observed in DU 145 prostate cancer cells stably overexpressing either the 1-141 or 1-173 isoform of PTHrP, where there was upregulation of Snail and vimentin and downregulation of E-cadherin relative to parental DU 145. By contrast, the opposite effect was observed in PC-3 prostate cancer cells where high levels of PTHrP were knocked-down via lentiviral siRNA transduction. Increased tumor progression was observed in PTHrP-overexpressing DU 145 cells while decreased progression was observed in PTHrP-knockdown PC-3 cells. PTHrP-overexpressing DU 145 formed larger tumors when implanted orthoptopically into nude mice and in one case resulted in spinal metastasis, an effect not observed among mice injected with parental DU 145 cells. PTHrP-overexpressing DU 145 cells also caused significant bone destruction when injected into the tibiae of nude mice, while parental DU 145 cells caused little to no destruction of bone. Together, these results suggest that PTHrP may work through EMT to promote an aggressive and metastatic phenotype in prostate cancer, a pathway of importance in cancer stem cells. Thus, continued efforts to elucidate the pathways involved in PTHrP-induced EMT as well as to develop ways to specifically target PTHrP signaling may lead to more effective therapies for prostate cancer.
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Affiliation(s)
- Weg M. Ongkeko
- Division of Otolaryngology-Head and Neck Surgery, Department of Surgery, University of California San Diego, La Jolla, California, United States of America
- * E-mail:
| | - Doug Burton
- Department of Medicine, Veterans Administration San Diego Healthcare System, University of California San Diego, La Jolla, California, United States of America
| | - Alan Kiang
- Division of Otolaryngology-Head and Neck Surgery, Department of Surgery, University of California San Diego, La Jolla, California, United States of America
| | - Eric Abhold
- Division of Otolaryngology-Head and Neck Surgery, Department of Surgery, University of California San Diego, La Jolla, California, United States of America
| | - Selena Z. Kuo
- Division of Otolaryngology-Head and Neck Surgery, Department of Surgery, University of California San Diego, La Jolla, California, United States of America
| | - Elham Rahimy
- Division of Otolaryngology-Head and Neck Surgery, Department of Surgery, University of California San Diego, La Jolla, California, United States of America
| | - Meng Yang
- AntiCancer, Inc., San Diego, California, United States of America
| | | | - Jessica Wang-Rodriguez
- Department of Pathology, University of California San Diego and the Veterans Administration San Diego Healthcare System, San Diego, California, United States of America
| | - Leonard J. Deftos
- Department of Medicine, Veterans Administration San Diego Healthcare System, University of California San Diego, La Jolla, California, United States of America
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Abstract
Lactation is the most extreme case of normal physiological bone loss during a lifetime, and breast cancers have a strong tendency to metastasize to bone. In both the physiological and pathological circumstances, parathyroid hormone-related peptide (PTHrP) plays a central role. Until recently there were no regulatory mechanisms to explain the induction of endocrine PTHrP secretion from breast cells during lactation. The mammary epithelium possesses a local serotonin signaling system which drives PTHrP expression during lactation and in breast cancer cells. The mammary gland serotonin system is highly induced in response to alveolar dilation due to milk secretion. Discovery of serotonergic control of PTHrP suggests that it may be possible to manipulate the breast-to-bone axis by targeting serotonin signaling.
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Affiliation(s)
- Nelson D Horseman
- Department of Molecular and Cellular Physiology, Program in Systems Biology and Physiology, University of Cincinnati, Cincinnati, OH 45267-0576, USA.
| | - Laura L Hernandez
- Department of Dairy Science, University of Wisconsin, Madison, Madison, WI 53706-1205, USA
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9
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Ohba S, Chung UI, Tei Y. [Identification of osteogenic signal and the development of artificial bones]. Clin Calcium 2013; 23:1723-1729. [PMID: 24292526] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
Mammalian skeletons are formed through two distinct processes, intramembranous ossification and endochondral ossification. During the endochondral ossification, indian hedgehog (Ihh) /parathyroid hormone-related protein (PTHrP) negative-feedback loop regulates the distance between epiphysis and the layer of hypertrophic chondrocytes. Ihh also stimulates bone formation. Based on such knowledge, bioactive molecule-loaded artificial bones are expected to achieve efficient bone regeneration without cell transplantation.
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Affiliation(s)
- Shinsuke Ohba
- Department of Bioengineering, The University of Tokyo Graduate School of Engineering, Japan
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Nishikawa N, Kanematsu A, Negoro H, Imamura M, Sugino Y, Okinami T, Yoshimura K, Hashitani H, Ogawa O. PTHrP is endogenous relaxant for spontaneous smooth muscle contraction in urinary bladder of female rat. Endocrinology 2013; 154:2058-68. [PMID: 23546599 DOI: 10.1210/en.2012-2142] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
Acute bladder distension causes various morphologic and functional changes, in part through altered gene expression. We aimed to investigate the physiologic role of PTHrP, which is up-regulated in an acute bladder distension model in female rats. In the control Empty group, bladders were kept empty for 6 hours, and in the Distension group, bladders were kept distended for 3 hours after an artificial storing-voiding cycle for 3 hours. In the Distention group bladder, up-regulation of transcripts was noted for 3 genes reported to be up-regulated by stretch in the cultured bladder smooth muscle cells in vitro. Further transcriptome analysis by microarray identified PTHrP as the 22nd highest gene up-regulated in Distension group bladder, among more than 27,000 genes. Localization of PTHrP and its functional receptor, PTH/PTHrP receptor 1 (PTH1R), were analyzed in the untreated rat bladders and cultured bladder cells using real-time RT-PCR and immunoblotting, which revealed that PTH1R and PTHrP were more predominantly expressed in smooth muscle than in urothelium. Exogenous PTHrP peptide (1-34) increased intracellular cAMP level in cultured bladder smooth muscle cells. In organ bath study using bladder strips, the PTHrP peptide caused a marked reduction in the amplitude of spontaneous contraction but caused only modest suppression for carbachol-induced contraction. In in vivo functional study by cystometrogram, the PTHrP peptide decreased voiding pressure and increased bladder compliance. Thus, PTHrP is a potent endogenous relaxant of bladder contraction, and autocrine or paracrine mechanism of the PTHrP-PTH1R axis is a physiologically relevant pathway functioning in the bladder.
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MESH Headings
- Animals
- Carbachol/pharmacology
- Cells, Cultured
- Cholinergic Agonists/pharmacology
- Cyclic AMP/metabolism
- Female
- Gene Expression Profiling
- Immunoblotting
- In Vitro Techniques
- Muscle Contraction/genetics
- Muscle Contraction/physiology
- Muscle, Smooth/metabolism
- Muscle, Smooth/physiopathology
- Myocytes, Smooth Muscle/drug effects
- Myocytes, Smooth Muscle/metabolism
- Oligonucleotide Array Sequence Analysis
- Parathyroid Hormone-Related Protein/genetics
- Parathyroid Hormone-Related Protein/metabolism
- Parathyroid Hormone-Related Protein/physiology
- Peptide Fragments/pharmacology
- Rats
- Rats, Sprague-Dawley
- Receptor, Parathyroid Hormone, Type 1/genetics
- Receptor, Parathyroid Hormone, Type 1/metabolism
- Receptor, Parathyroid Hormone, Type 1/physiology
- Reverse Transcriptase Polymerase Chain Reaction
- Urinary Bladder/metabolism
- Urinary Bladder/physiopathology
- Urinary Retention/genetics
- Urinary Retention/metabolism
- Urinary Retention/physiopathology
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Affiliation(s)
- Nobuyuki Nishikawa
- Department of Urology, Kyoto University Graduate School of Medicine, Kyoto, 606-8507, Japan
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11
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Wang M, VanHouten JN, Nasiri AR, Johnson RL, Broadus AE. PTHrP regulates the modeling of cortical bone surfaces at fibrous insertion sites during growth. J Bone Miner Res 2013; 28:598-607. [PMID: 23109045 PMCID: PMC3574208 DOI: 10.1002/jbmr.1801] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/25/2012] [Revised: 09/24/2012] [Accepted: 10/08/2012] [Indexed: 11/06/2022]
Abstract
The sites that receive ligament and tendon insertions (entheses) on the cortical surfaces of long bones are poorly understood, particularly regarding modeling and regulation. Entheses are classified as either fibrocartilaginous or fibrous based on their structures. Fibrous entheses typically insert into the metaphysis or diaphysis of a long bone, bear a periosteal component, and are modeled during long-bone growth. This modeling forms a root system by which the insertions attach to the cortical surface. In the case of the medial collateral ligament, modeling drives actual migration of the ligament along the cortical surface in order to accommodate linear growth, whereas in other sites modeling may excavate a deep cortical root system (eg, the teres major insertion) or a shallow root system with a large footprint (eg, the latissimus dorsi insertion). We report here that conditionally deleting parathyroid hormone-related protein (PTHrP) in fibrous entheses via Scleraxis-Cre targeting causes modeling to fail in these three iterations of osteoclast-driven enthesis excavation or migration. These iterations appear to represent formes frustes of a common modeling strategy, presumably differing from each other as a consequence of differences in biomechanical control. In sites in which PTHrP is not induced, either physiologically or because of conditional deletion, modeling does not take place and fibrocartilage is induced. These findings represent the initial genetic evidence that PTHrP regulates periosteal/intramembranous bone cell activity on cortical bone surfaces and indicate that PTHrP serves as a load-induced modeling tool in fibrous insertion sites during linear growth.
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Affiliation(s)
- Meina Wang
- Department of Internal Medicine, Yale University, New Haven, CT 06511
| | | | - Ali R. Nasiri
- Department of Internal Medicine, Yale University, New Haven, CT 06511
| | - Randy L. Johnson
- Department of Biochemistry and Molecular Biology, University of Texas, MD Anderson Cancer Center, Houston, TX 77030
| | - Arthur E. Broadus
- Department of Internal Medicine, Yale University, New Haven, CT 06511
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12
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Hochane M, Raison D, Coquard C, Imhoff O, Massfelder T, Moulin B, Helwig JJ, Barthelmebs M. Parathyroid hormone-related protein is a mitogenic and a survival factor of mesangial cells from male mice: role of intracrine and paracrine pathways. Endocrinology 2013; 154:853-64. [PMID: 23284101 DOI: 10.1210/en.2012-1802] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Glomerulonephritis is characterized by the proliferation and apoptosis of mesangial cells (MC). The parathyroid-hormone related protein (PTHrP) is a locally active cytokine that affects these phenomena in many cell types, through either paracrine or intracrine pathways. The aim of this study was to evaluate the effect of both PTHrP pathways on MC proliferation and apoptosis. In vitro studies were based on MC from male transgenic mice allowing PTHrP-gene excision by a CreLoxP system. MC were also transfected with different PTHrP constructs: wild type PTHrP, PTHrP devoid of its signal peptide, or of its nuclear localization sequence. The results showed that PTHrP deletion in MC reduced their proliferation even in the presence of serum and increased their apoptosis when serum-deprived. PTH1R activation by PTHrP(1-36) or PTH(1-34) had no effect on proliferation but improved MC survival. Transfection of MC with PTHrP devoid of its signal peptide significantly increased their proliferation and minimally reduced their apoptosis. Overexpression of PTHrP devoid of its nuclear localization sequence protected cells from apoptosis without changing their proliferation. Wild type PTHrP transfection conferred both mitogenic and survival effects, which seem independent of midregion and C-terminal PTHrP fragments. PTHrP-induced MC proliferation was associated with p27(Kip1) down-regulation and c-Myc/E2F1 up-regulation. PTHrP increased MC survival through the activation of cAMP/protein kinase A and PI3-K/Akt pathways. These results reveal that PTHrP is a cytokine of multiple roles in MC, acting as a mitogenic factor only through an intracrine pathway, and reducing apoptosis mainly through the paracrine pathway. Thus, PTHrP appears as a probable actor in MC injuries.
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Affiliation(s)
- Mazène Hochane
- Institut National de la Santé et de la Recherche Médicale U682, Equipe Cancer du Rein et Physiopathologie Rénale, Faculté de Médecine, 11 rue Humann, F-67085 Strasbourg, France.
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13
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Smith EL, Kanczler JM, Roberts CA, Oreffo ROC. Developmental cues for bone formation from parathyroid hormone and parathyroid hormone-related protein in an ex vivo organotypic culture system of embryonic chick femora. Tissue Eng Part C Methods 2012; 18:984-94. [PMID: 22690868 PMCID: PMC4014091 DOI: 10.1089/ten.tec.2012.0132] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/29/2012] [Accepted: 06/04/2012] [Indexed: 11/13/2022] Open
Abstract
Enhancement and application of our understanding of skeletal developmental biology is critical to developing tissue engineering approaches to bone repair. We propose that use of the developing embryonic femur as a model to further understand skeletogenesis, and the effects of key differentiation agents, will aid our understanding of the developing bone niche and inform bone reparation. We have used a three-dimensional organotypic culture system of embryonic chick femora to investigate the effects of two key skeletal differentiation agents, parathyroid hormone (PTH) and parathyroid hormone-related protein (PTHrP), on bone and cartilage development, using a combination of microcomputed tomography and histological analysis to assess tissue formation and structure, and cellular behavior. Stimulation of embryonic day 11 (E11) organotypic femur cultures with PTH and PTHrP initiated osteogenesis. Bone formation was enhanced, with increased collagen I and STRO-1 expression, and cartilage was reduced, with decreased chondrocyte proliferation, collagen II expression, and glycosaminoglycan levels. This study demonstrates the successful use of organotypic chick femur cultures as a model for bone development, evidenced by the ability of exogenous bioactive molecules to differentially modulate bone and cartilage formation. The organotypic model outlined provides a tool for analyzing key temporal stages of bone and cartilage development, providing a paradigm for translation of bone development to improve scaffolds and skeletal stem cell treatments for skeletal regenerative medicine.
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Affiliation(s)
- Emma L Smith
- Bone and Joint Research Group, Centre for Human Development, Stem Cells and Regeneration, Human Development and Health, Institute of Developmental Sciences, University of Southampton Medical School, Southampton, United Kingdom.
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14
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Abstract
PTHrP was identified as a cause of hypercalcemia in cancer patients 25 yr ago. In the intervening years, we have learned that PTHrP and PTH are encoded by related genes that are part of a larger "PTH gene family." This evolutionary relationship permits them to bind to the same type 1 PTH/PTHrP receptor, which explains why humoral hypercalcemia of malignancy resembles hyperparathyroidism. This review will outline basic facts about PTHrP biology and its normal physiological functions, with an emphasis on new findings of the past 5-10 yr. The medical and research communities first became aware of PTHrP because of its involvement in a common paraneoplastic syndrome. Now, research into the basic biology of PTHrP has suggested previously unrecognized connections to a variety of disease states such as osteoporosis, osteoarthritis, and breast cancer and has highlighted how PTHrP itself might be used in therapy for osteoporosis and diabetes. Therefore, the story of this remarkable protein is a paradigm for translational research, having gone from bedside to bench and now back to bedside.
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Affiliation(s)
- John J Wysolmerski
- Section of Endocrinology and Metabolism, Department of Internal Medicine, Yale School of Medicine, TAC S131, Box 208020, New Haven, Connecticut 06520-8020, USA.
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15
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Abstract
Bone remodeling is essential for adult bone homeostasis. The failure of this process often leads to the development of osteoporosis, a present major global health concern. The most important factor that affects normal bone remodeling is the tightly controlled and orchestrated regulation of osteoblasts and osteoclasts. The present review summarized the recent discoveries related to osteoblast regulation from several signals, including transforming growth factor-β, bone morphogenetic proteins, Wnt signal, Notch, Eph-Ephrin interaction, parathyroid hormone/parathyroid hormone-related peptide, and the leptin-serotonin-sympathetic nervous systemic pathway. The awareness of these mechanisms will facilitate further research that explores bone remodeling and osteoporosis. Future investigations on the endogenous regulation of osteoblastogenesis will increase the current knowledge required for the development of potential drug targets in the treatment of osteoporosis.
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Affiliation(s)
- C Zuo
- Key Laboratory of Stem Cell Biology, Institute of Health Sciences, Shanghai Jiao Tong University School of Medicine & Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, China
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16
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Tawfeek HA, Abou-Samra AB. Disruption of parathyroid hormone and parathyroid hormone-related peptide receptor phosphorylation prolongs ERK1/2 MAPK activation and enhances c-fos expression. Am J Physiol Endocrinol Metab 2012; 302:E1363-72. [PMID: 22414806 PMCID: PMC3378071 DOI: 10.1152/ajpendo.00034.2012] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Previous studies have demonstrated that parathyroid hormone (PTH) binding to the PTH/PTH-related peptide receptor (PPR) stimulates G protein coupling, receptor phosphorylation, β-arrestin translocation, and internalization of the ligand/receptor complex. The extracellular signal-regulated mitogen-activated protein kinases 1/2 (ERK1/2 MAPK) are downstream effectors of PPR. In the current study, we investigated the role of PPR phosphorylation in the PTH regulation of the ERK1/2 MAPK pathway. Short treatment with PTH (0-40 min) of LLCP-K(1) cells stably expressing a wild-type (WT) or a phosphorylation-deficient (PD) PPR (WT-PPR or PD-PPR cells, respectively) results in similar activation of ERK1/2. Interestingly, PTH stimulation of ERK1/2 in the WT-PPR cells then decreases as a result of longer PTH (60 min) treatment, and inhibition of ERK1/2 by PTH is observed at 90 min. Strikingly, the PD-PPR cells exhibit prolonged ERK1/2 activation up to 90 min of PTH treatment. An ERK1/2-dependent increase in c-fos expression is observed in the PD-PPR cells. Subsequently, c-fos expression in the WT-PPR and PD-PPR cells was markedly attenuated by a specific ERK1/2 pathway inhibitor. Further investigations revealed that PTH treatment causes a robust recruitment of a green fluorescent protein-tagged β-arrestin2 (β-arrestin2-GFP) in the WT-PPR cells. In contrast, β-arrestin2 recruitment was reduced in the PD-PPR cells. Importantly, expression of a receptor phosphorylation-independent β-arrestin2 (R169E) in the PD-PPR cells restored the biphasic effect of PTH on ERK1/2 as in the WT-PPR cells. The study reports a novel role for receptor phosphorylation and β-arrestin2 in the subsequent inhibition of the ERK1/2 pathway and in control of gene expression.
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Affiliation(s)
- Hesham A Tawfeek
- Center for Orthopaedic Research, Columbia University, 650 West 168th St., New York, NY 10032, USA.
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17
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Suda N. [Tooth and bone research using genetically modified mice]. Clin Calcium 2012; 22:27-31. [PMID: 22201096] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
Teeth and bone are both hard tissues and composed of hydroxyapatite. Tooth development initiates with the invasination of oral epithelium, followed by aggregation of supporting ectomesenchymal cells. From mouse study, numbers of molecules have been discovered to relate tooth development. These discoveries have helped to clarify the responsible genes of human genetic disorders with abnormal tooth number and structure. During tooth development, teeth erupt into the outer environment, oral cavity. From this point, teeth are completely different from bone which is always covered by soft tissues. Tooth eruption is composed of two different processes, that is, eruption pathway formation and vertical tooth movement. In this review, mutant mice with abnormal tooth development and eruption are introduced, and molecular mechanism required for this process is discussed.
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Affiliation(s)
- Naoto Suda
- Department of Human Development and Fostering, Meikai University School of Dentistry, Saitama, Japan
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18
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Tsumaki N. [Bone and calcium update; bone research update. Molecular mechanisms regulating chondrocyte differentiation and hypertrophy]. Clin Calcium 2011; 21:113-120. [PMID: 22133831] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
Chondrocyte differentiation process is composed of multiple steps. During the process, hypertrophy of chondrocyte is controlled by various factors including Indian hedgehog (Ihh) and parathyroid hormone related peptide (PTHrP) . PTHrP signals regulate HDAC4-MEF2C axis in chondrocyte. Recently, several co-factors have been found to interact with Sox9. Function of chondrocyte-specific microRNA has been determined. Several types of Cre transgenic mice are available to express Cre at various steps during chondrocyte differentiation. Using these mice, gene functions at specific steps of chondrocyte differentiation are analyzed by generating conditional knockout mice and conditional transgenic mice. It may be possible in future to induce chondrocytes from skin fibroblasts of patients with genetic cartilage diseases by using iPS cell technology, and to analyze molecular mechanism that control differentiation of human chondrocytes.
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Affiliation(s)
- Noriyuki Tsumaki
- Dept. of Cell Growth and Differentiation, Center for iPS Cell Research and Application, Kyoto University, Japan
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19
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Abstract
During embryonic and fetal development much of the skeleton initiates as a cartilaginous scaffold, which is progressively resorbed and replaced by bone. Endochondral bone formation continues until the growth plates fuse during puberty. At all life stages adequate delivery of mineral is required for the skeleton to achieve and maintain appropriate mineral content and strength. During fetal development the placenta actively transports calcium, phosphorus, and magnesium. Postnatally passive and then active absorption from the intestines becomes the main supply of minerals to the skeleton. Animal and human data indicate that fetal bone development requires parathyroid hormone (PTH) and PTH-related protein but not vitamin D/calcitriol, calcitonin, or (possibly) sex steroids. During the postnatal period, when intestinal calcium absorption becomes an active process, skeletal development begins to depend upon vitamin D/calcitriol but this requirement can be bypassed by increasing the calcium content of the diet or by administering intermittent calcium infusions.
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Affiliation(s)
- Christopher S Kovacs
- Medicine (Endocrinology and Metabolism), Obstetrics & Gynecology, and BioMedical Sciences, Faculty of Medicine, Memorial University of Newfoundland, Health Sciences Centre, 300 Prince Philip Drive, St. John's, Newfoundland, A1B 3V6, Canada.
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20
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Kurabayashi T. [Metabolic changes in bone and calcium in pregnancy and puerperium]. Clin Calcium 2011; 21:1335-1346. [PMID: 21881196] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
Calcium transfer from the mother to the fetus and neonate during pregnancy and lactation plays an extremely important role in the bone health of the mother and infant. Calcium aids in bone health through all ages but is especially crucial during pregnancy and lactation. Despite facing similar demands for calcium in pregnancy and puerperium, the maternal adaptations differ significantly between these two reproductive periods. Although the studies are underway to establish the conclusion, the changes in the structure and metabolism of bone and calcium during pregnancy and the early stage of postpartum are evaluated by investigating bone mineral density (BMD) , bone histomorphometry and bone markers of human or animal models. The bone resorption increased at the end of pregnancy and lactation, and the bone formation increases and the bone structure is almost recovered after cessation of lactating in postpartum. Vitamin D and parathyroid hormone-related protein (PTHrP) status especially becomes crucial for optimal maternal and fetal outcomes, fetal and neonatal skeletal growth, and maternal health in later life.
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Affiliation(s)
- Takumi Kurabayashi
- Department of Obatetrics and Gynecology, Niigata City General Hospital, Japan
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Peinado Cortés LM, Vanegas Acosta JC, Garzón Alvarado DA. A mechanobiological model of epiphysis structures formation. J Theor Biol 2011; 287:13-25. [PMID: 21810429 DOI: 10.1016/j.jtbi.2011.07.011] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2011] [Revised: 05/28/2011] [Accepted: 07/18/2011] [Indexed: 11/18/2022]
Abstract
Developing bone consists of epiphysis, metaphysis and diaphysis. The secondary ossification centre (SOC) appears and grows within the epiphysis, involving two histological stages. Firstly, cartilage canals appear; they carry hypertrophy factors towards the central area of the epiphysis. Canal growth and expansion is modulated by stress on the epiphysis. Secondly, the diffusion of hypertrophy factors causes SOC growth. Hypertrophy is regulated by biological and mechanical factors present within the epiphysis. The finite element method has been used for solving a coupled system of differential equations for modelling these histological stages of epiphyseal development. Cartilage canal spatial-temporal growth patterns were obtained as well as the SOC formation pattern. This model qualitatively agreed with experimental results reported by other authors.
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Affiliation(s)
- L M Peinado Cortés
- Mechanics and Materials Research Building 407, Office 203A, Universidad Nacional de Colombia, Bogotá, Colombia.
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22
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Ohta Y, Iwamoto M. [Joint morphogenesis and development of permanent articular cartilage]. Clin Calcium 2011; 21:813-819. [PMID: 21628794] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
During limb skeletogenesis progenitor mesenchymal cells aggregate at specific times and sites to form continuous precartilaginous condensations. With time the condensations undergo chondrogenesis and give rise to cartilaginous anlagen that exhibit incipient synovial joints at each end. A multitude of factors regulates subdivision into discrete skeletal elements and the formation, organization, morphogenesis and structure of the joints. This review summarizes recent advance of joint morphogenesis and actions of key players of joint and articular cartilage formation. In addition, we would like to discuss possible direction to translate basic research findings towards treatment of joint diseases.
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Affiliation(s)
- Yoichi Ohta
- Department of Surgery, The Children's Hospital of Philadelphia Research Institute, PA, USA
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23
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Mak IWY, Cowan RW, Turcotte RE, Singh G, Ghert M. PTHrP induces autocrine/paracrine proliferation of bone tumor cells through inhibition of apoptosis. PLoS One 2011; 6:e19975. [PMID: 21625386 PMCID: PMC3100318 DOI: 10.1371/journal.pone.0019975] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2010] [Accepted: 04/21/2011] [Indexed: 11/18/2022] Open
Abstract
Giant Cell Tumor of Bone (GCT) is an aggressive skeletal tumor characterized by local bone destruction, high recurrence rates and metastatic potential. Previous work in our lab has shown that the neoplastic cell of GCT is a proliferating pre-osteoblastic stromal cell in which the transcription factor Runx2 plays a role in regulating protein expression. One of the proteins expressed by these cells is parathryroid hormone-related protein (PTHrP). The objectives of this study were to determine the role played by PTHrP in GCT of bone with a focus on cell proliferation and apoptosis. Primary stromal cell cultures from 5 patients with GCT of bone and one lung metastsis were used for cell-based experiments. Control cell lines included a renal cell carcinoma (RCC) cell line and a human fetal osteoblast cell line. Cells were exposed to optimized concentrations of a PTHrP neutralizing antibody and were analyzed with the use of cell proliferation and apoptosis assays including mitochondrial dehydrogenase assays, crystal violet assays, APO-1 ELISAs, caspase activity assays, flow cytometry and immunofluorescent immunohistochemistry. Neutralization of PTHrP in the cell environment inhibited cell proliferation in a consistent manner and induced apoptosis in the GCT stromal cells, with the exception of those obtained from a lung metastasis. Cell cycle progression was not significantly affected by PTHrP neutralization. These findings indicate that PTHrP plays an autocrine/paracrine neoplastic role in GCT by allowing the proliferating stromal cells to evade apoptosis, possibly through non-traditional caspase-independent pathways. Thus PTHrP neutralizing immunotherapy is an intriguing potential therapeutic strategy for this tumor.
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Affiliation(s)
- Isabella W. Y. Mak
- Department of Surgery, McMaster University, Hamilton, Ontario, Canada
- Juravinski Cancer Centre, Hamilton Health Sciences, Hamilton, Ontario, Canada
| | - Robert W. Cowan
- Department of Medical Sciences, McMaster University, Hamilton, Ontario, Canada
- Juravinski Cancer Centre, Hamilton Health Sciences, Hamilton, Ontario, Canada
| | - Robert E. Turcotte
- Department of Orthopaedic Surgery, McGill University Health Centre, Montreal General Hospital, Montreal, Quebec, Canada
| | - Gurmit Singh
- Department of Pathology and Molecular Medicine, McMaster University, Hamilton, Ontario, Canada
- Juravinski Cancer Centre, Hamilton Health Sciences, Hamilton, Ontario, Canada
| | - Michelle Ghert
- Department of Surgery, McMaster University, Hamilton, Ontario, Canada
- Juravinski Cancer Centre, Hamilton Health Sciences, Hamilton, Ontario, Canada
- * E-mail:
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Hata K, Nakanishi M, Morita Y, Yoneda T. [Encounter of cancer cells with bone. The bone microenvironment and cancer metastases]. Clin Calcium 2011; 21:349-356. [PMID: 21358055] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
Bone is one of the most preferential metastatic target sites for cancers. However, based on the anatomical structure of the vascular system, bone is not recognized as a preferential metastatic target. Therefore, the biological crosstalk between metastatic cancer cells and bone is critical to the development and progression of bone metastases. Bone microenvironments possess unique biological features characterized by abundant growth factors and diverse cellular network including osteoblasts, osteoclasts and hematopietic cells. Cancers develop bone metastases by utilizing these unique bone environments for colonization and bone destruction. Better understandings of precise molecular mechanisms underlying cancer and bone crosstalk would contribute to the development of new therapeutic approaches for the treatment of bone metastasis at molecular levels.
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Affiliation(s)
- Kenji Hata
- Department of Biochemistry, Osaka University Graduate School of Dentistry
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25
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Hayashi S, Hanamura T. [Encounter of cancer cells with bone. Development of bone metastasis-specific targeting therapy]. Clin Calcium 2011; 21:389-396. [PMID: 21358060] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
Bone, as well as liver and lungs, is one of the most preferential metastatic targets for solid cancers including breast, prostate, and lung cancers. Control of the bone metastasis is clinically important ; because they are frequently associated with bone pain and pathological fracture which greatly diminish the quality of life for patients. Interaction between cancer cells and microenvironment of metastatic site play an important role for establishment of cancer metastasis. The understanding of their mechanisms has been improved in recent years, and they will be new therapeutic strategies to cure the bone metastasis. Bisphosphonates has been clinically used for the bone metastasis. In addition, RANKL-RANK targeted drugs and cathepsin K inhibitors are also expected to be fruitful drugs for the bone metastasis. In this review paper, we summarize the molecular mechanism of these drugs, especially with regarding to the breast cancer bone metastasis. Furthermore, we touch upon the ubiquitin ligase CHIP which recently found as a master gene in the progression and metastasis of breast cancer.
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Affiliation(s)
- Shinichi Hayashi
- Department of Molecular and Functional Dynamics, Tohoku University Graduate School of Medicine
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Abstract
Elongation of bones primarily occurs by endochondral ossification at the growth plate. In the growth plate, stem-like cells in the resting zone differentiate into rapidly dividing chondrocytes in the proliferative zone and then terminally differentiate into nondividing chondrocytes of the hypertrophic zone. The hypertrophic zone is then invaded by blood vessels and bone cell precursors, which remodel the newly formed cartilage into bone. The net effect is that new bone tissue is progressively generated at the bottom of the growth plate, resulting in bone elongation. The process of longitudinal bone growth is governed by a complex network of paracrine signals that maintain the unique structure and cellular kinetics of the growth plate. Recent progress in the understanding of important paracrine signals that regulate growth plate cartilage will be reviewed in this chapter.
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Guthalu Kondegowda N, Joshi-Gokhale S, Harb G, Williams K, Zhang XY, Takane KK, Zhang P, Scott DK, Stewart AF, Garcia-Ocaña A, Vasavada RC. Parathyroid hormone-related protein enhances human ß-cell proliferation and function with associated induction of cyclin-dependent kinase 2 and cyclin E expression. Diabetes 2010; 59:3131-8. [PMID: 20876711 PMCID: PMC2992775 DOI: 10.2337/db09-1796] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
OBJECTIVE Inducing human β-cell growth while enhancing function is a major goal in the treatment of diabetes. Parathyroid hormone-related protein (PTHrP) enhances rodent β-cell growth and function through the parathyroid hormone-1 receptor (PTH1R). Based on this, we hypothesized that PTH1R is expressed in human β-cells and that PTHrP has the potential to enhance human β-cell proliferation and/or function. RESEARCH DESIGN AND METHODS PTH1R expression, β-cell proliferation, glucose-stimulated insulin secretion (GSIS), and expression of differentiation and cell-cycle genes were analyzed in human islets transduced with adenoviral PTHrP constructs or treated with PTHrP peptides. The effect of overexpression of late G1/S cell cycle molecules was also assessed on human β-cell proliferation. RESULTS We found that human β-cells express PTH1R. More importantly, overexpression of PTHrP causes a significant approximately threefold increase in human β-cell proliferation. Furthermore, the amino terminus PTHrP(1-36) peptide is sufficient to increase replication as well as expression of the late G1/S cell-cycle proteins cyclin E and cyclin-dependent kinase 2 (cdk2) in human islets. Notably, PTHrP(1-36) also enhances GSIS. Finally, overexpression of cyclin E alone, but not cdk2, augments human β-cell proliferation, and when both molecules are expressed simultaneously there is a further marked synergistic increase in replication. CONCLUSIONS PTHrP(1-36) peptide enhances human β-cell proliferation as well as function, with associated upregulation of two specific cell-cycle activators that together can induce human β-cell proliferation several fold. The future therapeutic potential of PTHrP(1-36) for the treatment of diabetes is especially relevant given the complementary therapeutic efficacy of PTHrP(1-36) in postmenopausal osteoporosis.
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Marfori M, Mynott A, Ellis JJ, Mehdi AM, Saunders NFW, Curmi PM, Forwood JK, Bodén M, Kobe B. Molecular basis for specificity of nuclear import and prediction of nuclear localization. Biochim Biophys Acta 2010; 1813:1562-77. [PMID: 20977914 DOI: 10.1016/j.bbamcr.2010.10.013] [Citation(s) in RCA: 303] [Impact Index Per Article: 21.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Received: 06/15/2010] [Revised: 10/15/2010] [Accepted: 10/19/2010] [Indexed: 01/03/2023]
Abstract
Although proteins are translated on cytoplasmic ribosomes, many of these proteins play essential roles in the nucleus, mediating key cellular processes including but not limited to DNA replication and repair as well as transcription and RNA processing. Thus, understanding how these critical nuclear proteins are accurately targeted to the nucleus is of paramount importance in biology. Interaction and structural studies in the recent years have jointly revealed some general rules on the specificity determinants of the recognition of nuclear targeting signals by their specific receptors, at least for two nuclear import pathways: (i) the classical pathway, which involves the classical nuclear localization sequences (cNLSs) and the receptors importin-α/karyopherin-α and importin-β/karyopherin-β1; and (ii) the karyopherin-β2 pathway, which employs the proline-tyrosine (PY)-NLSs and the receptor transportin-1/karyopherin-β2. The understanding of specificity rules allows the prediction of protein nuclear localization. We review the current understanding of the molecular determinants of the specificity of nuclear import, focusing on the importin-α•cargo recognition, as well as the currently available databases and predictive tools relevant to nuclear localization. This article is part of a Special Issue entitled: Regulation of Signaling and Cellular Fate through Modulation of Nuclear Protein Import.
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Affiliation(s)
- Mary Marfori
- School of Chemistry and Molecular Biosciences, University of Queensland, Brisbane, Queensland 4072, Australia
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29
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Okazaki R. [Cytokines in bone diseases. Cytokines and malignancy-associated hypercalcemia]. Clin Calcium 2010; 20:1497-1502. [PMID: 20890031] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
Malignancy-associated hypercalcemia is one of the commonest causes of hypercalcemia. Clinically, it has been subdivided into HHM (humoral hypercelcemia of malignancy) and LOH (local osteolytic hypercalcemia) . PTHrP (PTH related protein) , which has high homology with PTH in its N-terminus and binds to a common receptor (PTH1R) with PTH, plays a central role in the development of hypercalcemia in HHM. Although most features of HHM can be explained by excessive action of circulating PTHrP, decreased serum level of 1,25 (OH) (2)D and markedly suppressed bone formation found in HHM cannot be explained by the action of N-terminus of PTHrP. Fragments of PTHrP that do not bind to PTH1R, found in the circulation of HHM patients, or some other cytokines secreted by cancer cells may modify the clinical features of HHM. PTHrP also plays important roles in the development of LOH in some cancers, such as breast cancer. In this article, the role of cytokines, mainly PTHrP, in MAH will be reviewed.
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Affiliation(s)
- Ryo Okazaki
- Third Department of Medicine, Teikyo University Chiba Medical Center
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30
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Ogata N. [Cytokines in bone diseases. Genetic defects of PTH/PTHrP receptor in chondrodysplasia]. Clin Calcium 2010; 20:1481-1488. [PMID: 20890029] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
Parathyroid hormone-related protein (PTHrP) signaling plays important roles in regulating the differentiation of chondrocytes in endochondral bone development. PTHrP signaling functions as an inhibitory effect on chondrocyte hypertrophy which is a terminal stage of differentiation at a growth plate. Mutations of the PTH÷PTHrP receptor have been identified in Jansen metaphyseal chondrodysplasia, Blomstrand's lethal chondrodysplasia, and enchondromatosis. Furthermore, genetic manipulations of the PTHrP and its receptor genes in mice have demonstrated the critical roles of these proteins in regulating both the switch between proliferation and differentiation of chondrocytes.
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Affiliation(s)
- Naoshi Ogata
- Division of Bone and Cartilage Regenerative Medicine, Division of Tissue Engineering,Faculty of Medicine, the University of Tokyo, Tokyo, Japan
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31
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Abstract
Parathyroid hormone (PTH), the active form of vitamin D, 1,25-dihydroxyvitamin D [1,25(OH)2D], and PTH-related peptide (PTHrP), the mediator of hypercalcemia of malignancy, are all osteolytic hormones. Recent studies have demonstrated that endogenous PTH and PTHrP also exert bone anabolic activity and that PTHrP is a crucial modulator of growth plate development. At least part of these PTHrP functions can be mediated by intracrine effects, involving a unique interplay of cell surface membrane and intracellular signaling. 1,25(OH)2D also exerts bone anabolic effects and, as with PTHrP, acts on multiple extraskeletal tissues. The skeletal functions of these hormones now extend beyond modulating bone resorption, and important extraskeletal activities have been discovered which involve unique local modes of action.
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Affiliation(s)
- David Goltzman
- Calcium Research Laboratory, Departments of Medicine, McGill University and McGill University Health Centre, Montreal, QC H3A1A1, Canada.
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32
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Amizuka N, Li M, Tamura M, Oda K. [Hormones and osteoporosis update. Histological aspects on the action of parathyroid hormone (PTH) and PTH-related peptide (PTHrP) on bone and cartilage]. Clin Calcium 2009; 19:935-943. [PMID: 19567988] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
Parathyroid hormone (PTH) and PTH-related peptide (PTHrP) , which were shown to bind the common receptor, PTH/PTHrP receptor, affect fetal chondrogenesis and adult bone turnover, respectively. PTH appears to predominantly stimulate proliferation of osteoblastic precursors, and consequently affect osteoblastic differentiation mediating coupling with osteoclasts. A recent study has reported the biological function of C-terminal region of PTHrP including nucleolar targeting signal. We will review recent reports for the action of PTH and PTHrP on bone and cartilage.
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Affiliation(s)
- Norio Amizuka
- Division of Oral Health Science, Hokkaido University Graduate School of Dental Medicine
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33
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Onan D, Allan EH, Quinn JMW, Gooi JH, Pompolo S, Sims NA, Gillespie MT, Martin TJ. The chemokine Cxcl1 is a novel target gene of parathyroid hormone (PTH)/PTH-related protein in committed osteoblasts. Endocrinology 2009; 150:2244-53. [PMID: 19147675 DOI: 10.1210/en.2008-1597] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
The PTH receptor (PTHR1) is expressed on osteoblasts and responds to PTH or PTHrP in an endocrine or autocrine/paracrine manner, respectively. A microarray study carried out on PTHR1-positive osteoblasts (Kusa 4b10 cells) identified the cysteine-X-cysteine (CXC) family chemokine ligand 1 (Cxcl1) as a novel immediate PTH/PTHrP-responsive gene. Cxcl1 is a potent neutrophil chemoattractant with recognized roles in angiogenesis and inflammation, but a role in bone biology has not been described. Cxcl1 mRNA levels were up-regulated 1 h after either PTH or PTHrP treatment of differentiated Kusa 4b10 osteoblasts (15-fold) and mouse calvarial osteoblasts (160-fold) and in rat metaphyseal bone (5-fold) 1 h after a single sc injection of PTH. Furthermore, PTH treatment stimulated a 10-fold increase in secreted Cxcl1 protein by both Kusa 4b10 cells and calvarial osteoblasts. Immunohistochemistry and PCR demonstrated that CXCR2, the receptor for Cxcl1, is highly expressed in osteoclast precursors (hemopoietic cells) but is predominantly undetectable in the osteoblast lineage, suggesting that osteoblast-derived Cxcl1 may act as a chemoattractant for osteoclast precursors. Confirming this hypothesis, recombinant Cxcl1 dose-dependently stimulated migration of osteoclast precursors in cell culture studies, as did conditioned media from Kusa 4b10 cells treated with PTH. These data indicate that local action through the PTHR1 could stimulate cells of the osteoblast lineage to release a chemokine capable of attracting osteoclast precursors to the bone environment.
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Affiliation(s)
- Döne Onan
- Bone Joint and Cancer Unit, St. Vincent's Institute, Fitzroy, Victoria 3065, Australia
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Lozano D, de Castro LF, Dapía S, Andrade-Zapata I, Manzarbeitia F, Alvarez-Arroyo MV, Gómez-Barrena E, Esbrit P. Role of parathyroid hormone-related protein in the decreased osteoblast function in diabetes-related osteopenia. Endocrinology 2009; 150:2027-35. [PMID: 19196804 DOI: 10.1210/en.2008-1108] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
A deficit in bone formation is a major factor in diabetes-related osteopenia. We examined here whether diabetes-associated changes in osteoblast phenotype might in part result from a decrease in PTH-related protein (PTHrP). We used a bone marrow ablation model in diabetic mice by multiple streptozotocin injections. PTHrP (1-36) (100 microg/kg, every other day) or vehicle was administered to mice for 13 d starting 1 wk before marrow ablation. Diabetic mice showed bone loss in both the intact femur and the regenerating tibia on d 6 after ablation; in the latter, this was related to decreased bone-forming cells, osteoid surface, and blood vessels, and increased marrow adiposity. Moreover, a decrease in matrix mineralization occurred in ex vivo bone marrow cultures from the unablated tibia from diabetic mice. These skeletal alterations were associated with decreased gene expression (by real-time PCR) of Runx2, osterix, osteocalcin, PTHrP, the PTH type 1 receptor, vascular endothelial growth factor and its receptors, and osteoprotegerin to receptor activator of nuclear factor-kappaB ligand mRNA ratio, and increased peroxisome proliferator-activated receptor-gamma2 mRNA levels. Similar changes were induced by hyperosmotic (high glucose or mannitol) medium in osteoblastic MC3T3-E1 cells, which were mimicked by adding a neutralizing anti-PTHrP antibody or PTH type 1 receptor antagonists to these cells in normal glucose medium. PTHrP (1-36) administration reversed these changes in both intact and regenerating bones from diabetic mice in vivo, and in MC3T3-E1 cells exposed to high glucose. These findings strongly suggest that PTHrP has an important role in the altered osteoblastic function related to diabetes.
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Affiliation(s)
- Daniel Lozano
- Laboratorio de Metabolismo Mineral y Oseo, Fundación Jiménez Díaz (Capio Group), Avenida. Reyes Católicos, 2, 28040 Madrid, Spain
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35
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Allgrove J. Voyages of discovery. Endocr Dev 2009; 16:1-7. [PMID: 19494657 DOI: 10.1159/000223684] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
The metabolism of calcium and bone is controlled by five principal hormones: parathyroid hormone, 1,25-dihydroxyvitamin D, calcitonin, parathyroid hormone-related peptide and fibroblast growth factor 23, some of which have been known for several decades and some of which have only recently been identified. The stories of discovery of these hormones have constituted a series of complex journeys which have been undertaken over the past century or so and none of which has yet been completed. The complexities of bone and calcium metabolism have been and remain, to many people, somewhat mysterious and a daunting task to understand. This book is designed to try to unravel those mysteries and present them in an interesting and comprehensible manner.
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Affiliation(s)
- Jeremy Allgrove
- Department of Paediatric Endocrinology, Royal London Hospital, Whitechapel, London, UK.
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Abstract
Type 2 diabetes mellitus is a complex disease characterized by beta-cell failure in the setting of insulin resistance. In early stages of the disease, pancreatic beta-cells adapt to insulin resistance by increasing mass and function. As nutrient excess persists, hyperglycemia and elevated free fatty acids negatively impact beta-cell function. This happens by numerous mechanisms, including the generation of reactive oxygen species, alterations in metabolic pathways, increases in intracellular calcium and the activation of endoplasmic reticulum stress. These processes adversely affect beta-cells by impairing insulin secretion, decreasing insulin gene expression and ultimately causing apoptosis. In this review, we will first discuss the regulation of beta-cell mass during normal conditions. Then, we will discuss the mechanisms of beta-cell failure, including glucotoxicity, lipotoxicity and endoplasmic reticulum stress. Further research into mechanisms will reveal the key modulators of beta-cell failure and thus identify possible novel therapeutic targets. Type 2 diabetes mellitus is a multifactorial disease that has greatly risen in prevalence in part due to the obesity and inactivity that characterize the modern Western lifestyle. Pancreatic beta-cells possess the potential to greatly expand their function and mass in both physiologic and pathologic states of nutrient excess and increased insulin demand. beta-cell response to nutrient excess occurs by several mechanisms, including hypertrophy and proliferation of existing beta-cells, increased insulin production and secretion, and formation of new beta-cells from progenitor cells [1, 2]. Failure of pancreatic beta-cells to adequately expand in settings of increased insulin demand results in hyperglycemia and diabetes. In this review, we will first discuss the factors involved in beta-cell growth and then discuss the mechanisms by which beta-cell expansion fails and leads to beta-cell failure and diabetes (Fig. 1).
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Affiliation(s)
- KJ Chang-Chen
- Washington University School of Medicine, Division of Endocrinology, Metabolism & Lipid Research, St. Louis, Missouri, USA
| | - R Mullur
- Division of Medical Education, Department of Internal Medicine, Washington University School of Medicine
| | - E Bernal-Mizrachi
- To whom correspondence should be addressed: Ernesto Bernal-Mizrachi, Washington University School of Medicine, 660 S. Euclid Avenue, Campus Box 8127, St. Louis, MO 63110, USA. Phone: (314) 362-7693 Fax: (314) 747-2692
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Nishioka K, Itoh S, Suemoto H, Kanno S, Gai Z, Kawakatsu M, Tanishima H, Morimoto Y, Hatamura I, Yoshida M, Muragaki Y. Trps1 deficiency enlarges the proliferative zone of growth plate cartilage by upregulation of Pthrp. Bone 2008; 43:64-71. [PMID: 18456591 DOI: 10.1016/j.bone.2008.03.009] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/14/2007] [Revised: 02/27/2008] [Accepted: 03/13/2008] [Indexed: 10/22/2022]
Abstract
We have reported that elongation of the columnar proliferative zone of long bone growth plates in Trps1-/- mice during the late fetal stage in the previous study [1]. Since expression of Trps1 protein was found to overlap with that of mRNAs for Indian hedgehog (Ihh), PTH/PTHrP receptor (PPR), and PTHrP, we hypothesized that Trps1 may inhibit the hypertrophic differentiation of chondrocytes by interacting with the Ihh/PTHrP feedback loop. To investigate whether Trps1 has a role in this Ihh/PTHrP feedback loop, we compared the growth plates of Trps1-/- mice and wild-type (Trps1+/+) mice. Immunohistochemistry showed that Trps1 protein was strongly expressed in the periarticular and prehypertrophic zones of the fetal growth plate in wild-type mice on embryonic day 18.5 (E18.5). On the other hand, Ihh, PPR, and PTHrP mRNAs were predominantly expressed in the prehypertrophic zone at this stage of development. While expression of Ihh and PPR by prehypertrophic chondrocytes was unaffected in the growth plates of Trps1-/- mice, the range of PTHrP expression was expanded toward the proliferating zone in these mice. Quantitative real-time PCR analysis demonstrated upregulation of PTHrP in the epiphyseal growth plates of Trps1-/- mice. Furthermore, promoter analysis combined with the chromatin immunoprecipitation (ChIP) assay demonstrated that direct binding of Trps1 to the PTHrP promoter suppressed the transcription of PTHrP. Finally, organ culture of E14.5 tibiae in the absence or the presence of Pthrp revealed that the proliferative zone of the tibial growth plate was elongated by culture with Pthrp compared to that of control tibiae. Taken together, these data provide the first genetic evidence that lack of Trps1 leads to overexpression of PTHrP, and that Trps1 is required to maintain the normal organization of chondrocytes in the growth plate.
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Affiliation(s)
- Katsuhiro Nishioka
- First Department of Pathology, Wakayama Medical University School of Medicine, 811-1 Kimiidera, Wakayama 641-0012, Japan
| | - Shunji Itoh
- First Department of Pathology, Wakayama Medical University School of Medicine, 811-1 Kimiidera, Wakayama 641-0012, Japan
| | - Hiroki Suemoto
- First Department of Pathology, Wakayama Medical University School of Medicine, 811-1 Kimiidera, Wakayama 641-0012, Japan
| | - Seiji Kanno
- Department of Orthopedic Surgery, Wakayama Medical University School of Medicine, Wakayama, 641-0012, Japan
| | - Zhibo Gai
- First Department of Pathology, Wakayama Medical University School of Medicine, 811-1 Kimiidera, Wakayama 641-0012, Japan
| | - Motohisa Kawakatsu
- First Department of Pathology, Wakayama Medical University School of Medicine, 811-1 Kimiidera, Wakayama 641-0012, Japan
| | - Hiroyuki Tanishima
- First Department of Pathology, Wakayama Medical University School of Medicine, 811-1 Kimiidera, Wakayama 641-0012, Japan
| | - Yoshifumi Morimoto
- First Department of Pathology, Wakayama Medical University School of Medicine, 811-1 Kimiidera, Wakayama 641-0012, Japan
| | - Ikuji Hatamura
- First Department of Pathology, Wakayama Medical University School of Medicine, 811-1 Kimiidera, Wakayama 641-0012, Japan
| | - Munehito Yoshida
- Department of Orthopedic Surgery, Wakayama Medical University School of Medicine, Wakayama, 641-0012, Japan
| | - Yasuteru Muragaki
- First Department of Pathology, Wakayama Medical University School of Medicine, 811-1 Kimiidera, Wakayama 641-0012, Japan.
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38
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Kurebayashi J. [Bone-related events in breast cancer]. Clin Calcium 2008; 18:447-454. [PMID: 18379025] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
Breast cancer most frequently causes bone metastases in solid tumors. It has been known that there is a vicious cycle consisting of tumor cells, osteoblasts, osteoclasts and various humoral factors in osteolytic lesions. Although systemic therapy is a main treatment of bone metastases, local therapies, such as radiotherapy and surgical therapy, are also promptly needed when bone-related complications occur. In recent years, anti-osteoclast agents, bisphosphonates significantly contribute to the delay of occurrence of bone-related complications. Postoperative adjuvant therapy significantly reduces the incidence of recurrence in breast cancer patients. Chemotherapy and LH-RH agonists cause ovarian function suppression in premenopausal patients, and aromatase inhibitors cause estrogen deprivation in postmenopausal patients. These effects cause unbalance of bone metabolism, loss of bone density and increase in the incidence of fractures. Improvement of these bone-related adverse effects and careful follow-ups are needed for breast cancer patients.
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Onuma E, Okabe H. [PTHrP and cancer cachexia]. Clin Calcium 2008; 18:489-498. [PMID: 18379031] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
Parathyroid hormone-related peptide (PTHrP) was discovered to be a causative factor of humoral hypercalcemia of malignancy (HHM) . It also causes cachexia including reduced food intake, body weight loss, and decreased locomotor activity by a mechanism that is independent of hypercalcemia and proinflammatory cytokine actions. PTHrP-induced cachexia is not associated with the repression of orexigenic peptides or induction of anorexigenic peptides ; unexpectedly, the expression of orexigenic peptides was increased and that of anorexigenic peptides was decreased in animals that developed PTHrP-induced cachexia. A neutralizing antibody against PTHrP rapidly restored food intake, body weight, and locomotor activity and also normalized the expression of orexigenic and anorexigenic peptides. Thus, PTHrP induces cachexia by mechanisms other than directly affecting the hypothalamic feeding regulated peptides.
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Affiliation(s)
- Etsuro Onuma
- Chugai Pharmaceutical Co., Ltd., Product Research Department
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Shen X, Rychahou PG, Evers BM, Falzon M. PTHrP increases xenograft growth and promotes integrin alpha6beta4 expression and Akt activation in colon cancer. Cancer Lett 2007; 258:241-52. [PMID: 17964713 PMCID: PMC2180421 DOI: 10.1016/j.canlet.2007.09.010] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2007] [Revised: 09/05/2007] [Accepted: 09/11/2007] [Indexed: 11/23/2022]
Abstract
Parathyroid hormone-related protein (PTHrP) is expressed by human colon cancer tissue and cell lines. Expression of PTHrP and phosphatidylinositol 3-kinase (PI3-K) pathway components correlates with the severity of colon carcinoma. Here we observed a positive effect of endogenous PTHrP on LoVo (human colon cancer) cell proliferation, migration, invasion, integrin alpha6 and beta4 expression, and p-Akt levels. There was a direct correlation between PTHrP expression and anchorage-independent cell growth. PTHrP significantly increased xenograft growth; tumors from PTHrP-overexpressing cells showed increased expression of integrins alpha6 and beta4, and PI3-K pathway components. The higher expression of PTHrP in human colon cancer adenocarcinoma vs. normal colonic mucosa was accompanied by increased integrin alpha6 and beta4 levels. Elevated PTHrP expression in colon cancer may thus upregulate integrin alpha6beta4 expression, with consequent PI3-K activation. Targeting PTHrP might result in effective inhibition of tumor growth, migration, and invasion.
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Affiliation(s)
- Xiaoli Shen
- Department of Pharmacology and Toxicology, University of Texas Medical Branch, Galveston, TX 77555
| | - Piotr G. Rychahou
- Department of Surgery, University of Texas Medical Branch, Galveston, TX 77555
| | - B. Mark Evers
- Department of Surgery, University of Texas Medical Branch, Galveston, TX 77555
- Sealy Center for Cancer Cell Biology, University of Texas Medical Branch, Galveston, TX 77555
| | - Miriam Falzon
- Department of Pharmacology and Toxicology, University of Texas Medical Branch, Galveston, TX 77555
- Sealy Center for Cancer Cell Biology, University of Texas Medical Branch, Galveston, TX 77555
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Vasavada RC, Wang L, Fujinaka Y, Takane KK, Rosa TC, Mellado-Gil JMD, Friedman PA, Garcia-Ocaña A. Protein kinase C-zeta activation markedly enhances beta-cell proliferation: an essential role in growth factor mediated beta-cell mitogenesis. Diabetes 2007; 56:2732-43. [PMID: 17686945 DOI: 10.2337/db07-0461] [Citation(s) in RCA: 67] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
OBJECTIVE Diabetes results from a deficiency of functional beta-cells. Previous studies have identified hepatocyte growth factor (HGF) and parathyroid hormone-related protein (PTHrP) as two potent beta-cell mitogens. The objective of this study is to determine 1) whether HGF and PTHrP have additive/synergistic effects on beta-cell growth and proliferation; 2) the signaling pathways through which these growth factors mediate beta-cell mitogenesis; and 3) whether activation of this/these signaling pathway(s) enhances human beta-cell replication. RESEARCH DESIGN AND METHODS We generated and phenotypically analyzed doubly transgenic mice overexpressing PTHrP and HGF in the beta-cell. INS-1 and primary mouse and human islet cells were used to identify mitogenic signaling pathways activated by HGF and/or PTHrP. RESULTS Combined overexpression of HGF and PTHrP in the beta-cell of doubly transgenic mice did not result in additive/synergistic effects on beta-cell growth and proliferation, suggesting potential cross-talk between signaling pathways activated by both growth factors. Examination of these signaling pathways in INS-1 cells revealed atypical protein kinase C (PKC) as a novel intracellular target activated by both HGF and PTHrP in beta-cells. Knockdown of PKC zeta, but not PKC iota/lambda, expression using specific small-interfering RNAs blocked growth factor-induced INS-1 cell proliferation. Furthermore, adenovirus-mediated delivery of kinase-dead PKC zeta completely inhibited beta-cell proliferation in primary islet cells overexpressing PTHrP and/or HGF. Finally, adenovirus-mediated delivery of constitutively active PKC zeta in mouse and human primary islet cells significantly enhanced beta-cell proliferation. CONCLUSIONS PKC zeta is essential for PTHrP- and HGF-induced beta-cell proliferation. PKC zeta activation could be useful in therapeutic strategies for expanding beta-cell mass in vitro and in vivo.
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Affiliation(s)
- Rupangi C Vasavada
- Department of Medicine, Division of Endocrinology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania 15261, USA
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Abstract
In cartilage and bone-producing cells, proliferation and growth are balanced with terminal differentiation. Maintaining this balance is essential for modeling, growth, and maintenance of the skeleton. Cartilage growth follows a program regulated by hormones and cytokines interacting with a counter-regulatory system in which hedgehog and parathyroid hormone (PTH)-rP signals are key elements. This maintains chondrocyte proliferation and, at specific sites, allows differentiation. Bone is produced by differentiation of mesenchymal stem cells on a scaffold of mineralizing cartilage. However, bone, once formed, is continually resorbed and replaced. Thus, maintenance of bone mass requires retention of stem cells and preosteoblasts in undifferentiated division-competent stages. Maintenance of the undifferentiated states is poorly understood, whereas the rate of osteoblast formation is regulated in part by PTH and insulin-like growth factor. The precursor pool is also subject to depletion by differentiation of mesenchymal stem cells to nonbone cells including adipocytes. In the aging skeleton, disordered balance between bone formation and resorption is in major part due to immune dysregulation that increases formation of bone-degrading osteoclasts; tumor necrosis factor (TNF)-alpha is a major intermediate in this process.
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Affiliation(s)
- Harry C Blair
- Department of Pathology, University of Pittsburgh, Pittsburgh, PA 15261, USA.
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43
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Ortega A, Pérez de Prada MT, Mateos-Cáceres PJ, Ramos Mozo P, González-Armengol JJ, González Del Castillo JM, Martín Sánchez J, Villarroel P, Santiago JL, Bosch RJ, Macaya C, Esbrit P, López-Farré AJ. Effect of parathyroid-hormone-related protein on human platelet activation. Clin Sci (Lond) 2007; 113:319-27. [PMID: 17501718 DOI: 10.1042/cs20070010] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Evidence suggests that PTHrP [PTH (parathyroid hormone)-related protein] can act as an inflammatory mediator in several pathological settings including cardiovascular disease. The aim of the present study was to determine whether PTHrP might be involved in human platelet activation. We used a turbidimetric method to determine platelet aggregation. The expression of PTH1R (PTH type 1 receptor) in human platelets was analysed by Western blot and flow cytometry analyses. PTHrP-(1–36) (10−7 mol/l) by itself failed to modify the activation of platelets. However, it significantly enhanced ADP-induced platelet activation, and also increased the ability of other agonists (thrombin, collagen and arachidonic acid) to induce platelet aggregation. H89 (10−6 mol/l) and 25×10−6 mol/l Rp-cAMPS (adenosine 3′,5′-cyclic monophosphorothioate Rp-isomer), two protein kinase A inhibitors, and 25×10−9 mol/l bisindolylmaleimide I, a protein kinase C inhibitor, partially decreased the enhancing effect of PTHrP-(1–36) on ADP-induced platelet activation. Meanwhile, 10−6 mol/l PTHrP-(7–34), a PTH1R antagonist, as well as 10−5 mol/l PD098059, a MAPK (mitogen-activated protein kinase) inhibitor, or a farnesyltransferase inhibitor abolished this effect of PTHrP-(1–36). Moreover, 10−7 mol/l PTHrP-(1–36) increased (2-fold over control) MAPK activation in human platelets. PTH1R was detected in platelets, and the number of platelets expressing it on their surface in patients during AMI (acute myocardial infarction) was not different from that in a group of patients with similar cardiovascular risk factors without AMI. Western blot analysis showed that total PTH1R protein levels were markedly higher in platelets from control than those from AMI patients. PTH1R was found in plasma, where its levels were increased in AMI patients compared with controls. In conclusion, human platelets express the PTH1R. PTHrP can interact with this receptor to enhance human platelet activation induced by several agonists through a MAPK-dependent mechanism.
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Affiliation(s)
- Arantxa Ortega
- Bone and Mineral Metabolism Laboratory, Fundación Jiménez Díaz, Madrid, Spain
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Abstract
Although endochondral ossification of the limb and axial skeleton is relatively well-understood, the development of dermal (intramembranous) bone featured by many craniofacial skeletal elements is not nearly as well-characterized. We analyzed the expression domains of a number of markers that have previously been associated with endochondral skeleton development to define the cellular transitions involved in the dermal ossification process in both chick and mouse. This led to the recognition of a series of distinct steps in the dermal differentiation pathways, including a unique cell type characterized by the expression of both osteogenic and chondrogenic markers. Several signaling molecules previously implicated in endochondrial development were found to be expressed during specific stages of dermal bone formation. Three of these were studied functionally using retroviral misexpression. We found that activity of bone morphogenic proteins (BMPs) is required for neural crest-derived mesenchyme to commit to the osteogenic pathway and that both Indian hedgehog (IHH) and parathyroid hormone-related protein (PTHrP, PTHLH)negatively regulate the transition from preosteoblastic progenitors to osteoblasts. These results provide a framework for understanding dermal bone development with an aim of bringing it closer to the molecular and cellular resolution available for the endochondral bone development.
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Affiliation(s)
- Arhat Abzhanov
- Department of Genetics, Harvard Medical School, Boston, MA 02115, USA
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Abstract
The skeletal system is the most frequent metastatic site of hematogenous spread of urologic carcinomas. Osseus metastases are classified as osteoneutral, osteolytic, osteoblastic and combinations thereof. Osteolytic metastases lead to bone resorption by activating osteoclasts, while osteoblastic metastases stimulate osteoblasts by paracrine mechanisms. The local osteoblastic effect is associated with secondary systemic bone resorption. The use of bisphosphonates is now an established supportive therapy and newer treatment strategies including targeted intervention in the pathophysiology of bone metastases and radioimmunotherapy are being applied or will be coming soon.
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Affiliation(s)
- G Sauer
- Institut für Pathologie, Universitätsklinikum Ulm, Albert-Einstein-Allee 11, 89081, Ulm
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Abstract
A brief description is given of the discovery of PTHrP and the roles of the peptide in mammalian physiology. Next, the occurrence of PTHrP in the earliest vertebrates, sharks, skates and fishes, is reviewed and the calciotropic functions of PTHrP are addressed more specifically in fishes. Parathyroid hormone-related protein (PTHrP) is a hypercalcemic hormone in teleostean fishes, but also has para- and autocrine functions. After the isolation and identification of fish PTHrP and PTHrP receptors and the subsequent development of recombinant protein and a real-time quantitative PCR, a calciotropic role of PTHrP in fish physiology could be assessed. PTHrP influences calcium physiology via regulation of calcium mobilisation from internal sources (bone and scales) and via calcium uptake from the environment (water and diet). Continuous variations in the need for calcium and in the availability of environmental calcium require fast calciotropes to guarantee calcium balance, in which PTHrP is pivotal for the fish. PTHrP is essential in fish bone physiology, e.g. in mineralisation and calcium reabsorption from the scales. Moreover, PTHrP plays a role in vitellogenesis, cortisol production, regulation of renal Mrp2 activity and melatonin synthesis. The plethora of functions of PTHrP in fish concern endocrine, paracrine and autocrine (and possibly intracrine) functions; calciotropic actions of PTHrP at the organismal and cellular level are prominent in fish. The strong conservation of the pthrp gene in the vertebrate lineage and the N-terminal similarity of the coded proteins relates to the important role of PTHrP in calcium physiology that is of paramount importance to all physiological processes. Recent and ongoing studies will contribute to our rapidly expanding knowledge of the original physiological functions of PTHrP in teleost fish.
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Affiliation(s)
- Wout Abbink
- Department of Animal Physiology, Radboud University Nijmegen, Toernooiveld 1, 6525 ED Nijmegen, The Netherlands
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Abstract
Root resorption is a physiologic event for the primary teeth. It is still unclear whether odontoclasts, the cells which resorb the dental hard tissue, are different from the osteoclasts, the cells that resorb bone. Root resorption seems to be initiated and regulated by the stellate reticulum and the dental follicle of the underlying permanent tooth via the secretion of stimulatory molecules, i.e. cytokines and transcription factors. The primary root resorption process is regulated in a manner similar to bone remodeling, involving the same receptor ligand system known as RANK/RANKL (receptor activator of nuclear factor-kappa B/ RANK Ligand). Primary teeth without a permanent successor eventually exfoliate as well, but our current understanding on the underlying mechanism is slim. The literature is also vague on how resorption of the pulp and periodontal ligament of the primary teeth occurs. Knowledge on the mechanisms involved in the physiologic root resorption process may enable us to delay or even inhibit exfoliation of primary teeth in those cases that the permanent successor teeth are not present and thus preservation of the primary teeth is desirable.
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Hashimoto H, Azuma Y, Kawasaki M, Fujihara H, Onuma E, Yamada-Okabe H, Takuwa Y, Ogata E, Ueta Y. Parathyroid hormone-related protein induces cachectic syndromes without directly modulating the expression of hypothalamic feeding-regulating peptides. Clin Cancer Res 2007; 13:292-8. [PMID: 17200368 DOI: 10.1158/1078-0432.ccr-06-1487] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
PURPOSE Parathyroid hormone-related protein (PTHrP) is a causative factor of humoral hypercalcemia of malignancy (HHM) and concurrent anorexia and wasting. Because changes in the expression of hypothalamic feeding-regulating peptides can directly affect appetites and thereby can cause anorexia and wasting, we addressed whether the cachectic syndromes induced by PTHrP rely on the action of hypothalamic feeding-regulating peptides. EXPERIMENTAL DESIGN Rats were inoculated with a LC-6 human cancer xenograft that secreted PTHrP, and the mRNA levels of the hypothalamic feeding-regulating peptide genes and serum leptin levels were examined before and after the development of HHM by in situ hybridization histochemistry and ELISA, respectively. Some rats were given the anti-PTHrP antibody. RESULTS AND CONCLUSION The mRNA levels for the orexigenic peptides, such as the agouti-related protein and the neuropeptide Y in the arcuate nucleus (Arc), were significantly increased after the development of HHM, whereas the mRNA levels for the anorexigenic peptides, such as the proopiomelanocortin in the Arc, the cocaine and amphetamine-regulated transcript in the Arc, and the corticotropin-releasing factor in the paraventricular nucleus, were significantly decreased after the development of HHM. Plasma leptin levels were also reduced in cachectic rats, and the administration of anti-PTHrP antibody to the cachectic rats not only improved the cachectic symptoms but also restored the mRNA levels of these orexigenic and anorexigenic peptides, except for orexin. Thus, PTHrP induces HHM and concurrent cachectic syndromes by mechanisms other than directly modulating the leptin or hypothalamic feeding-regulated peptides.
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Affiliation(s)
- Hirofumi Hashimoto
- Department of Physiology, School of Medicine, University of Occupational and Environmental Health, Kitakyushu, Japan
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Tanaka Y, Okada Y. [Progress in therapy and diagnosis: Hypercalcemia due to parathyroid hormone-related protein producing neoplasms]. Nihon Naika Gakkai Zasshi 2007; 96:669-74. [PMID: 17506302 DOI: 10.2169/naika.96.669] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/15/2023]
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Abe M. [Progress in diagnosis and therapy: Hypercalcemia due to multiple myeloma and wide-spread neoplastic bone metastasis]. Nihon Naika Gakkai Zasshi 2007; 96:675-80. [PMID: 17506303 DOI: 10.2169/naika.96.675] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/15/2023]
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