1
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Brent MB. Pharmaceutical treatment of bone loss: From animal models and drug development to future treatment strategies. Pharmacol Ther 2023; 244:108383. [PMID: 36933702 DOI: 10.1016/j.pharmthera.2023.108383] [Citation(s) in RCA: 12] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2022] [Revised: 02/18/2023] [Accepted: 03/09/2023] [Indexed: 03/17/2023]
Abstract
Animal models are fundamental to advance our knowledge of the underlying pathophysiology of bone loss and to study pharmaceutical countermeasures against it. The animal model of post-menopausal osteoporosis from ovariectomy is the most widely used preclinical approach to study skeletal deterioration. However, several other animal models exist, each with unique characteristics such as bone loss from disuse, lactation, glucocorticoid excess, or exposure to hypobaric hypoxia. The present review aimed to provide a comprehensive overview of these animal models to emphasize the importance and significance of investigating bone loss and pharmaceutical countermeasures from perspectives other than post-menopausal osteoporosis only. Hence, the pathophysiology and underlying cellular mechanisms involved in the various types of bone loss are different, and this might influence which prevention and treatment strategies are the most effective. In addition, the review sought to map the current landscape of pharmaceutical countermeasures against osteoporosis with an emphasis on how drug development has changed from being driven by clinical observations and enhancement or repurposing of existing drugs to today's use of targeted anti-bodies that are the result of advanced insights into the underlying molecular mechanisms of bone formation and resorption. Moreover, new treatment combinations or repurposing opportunities of already approved drugs with a focus on dabigatran, parathyroid hormone and abaloparatide, growth hormone, inhibitors of the activin signaling pathway, acetazolamide, zoledronate, and romosozumab are discussed. Despite the considerable progress in drug development, there is still a clear need to improve treatment strategies and develop new pharmaceuticals against various types of osteoporosis. The review also highlights that new treatment indications should be explored using multiple animal models of bone loss in order to ensure a broad representation of different types of skeletal deterioration instead of mainly focusing on primary osteoporosis from post-menopausal estrogen deficiency.
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Affiliation(s)
- Mikkel Bo Brent
- Department of Biomedicine, Aarhus University, Denmark, Wilhelm Meyers Allé 3, 8000 Aarhus C, Denmark.
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2
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Chen L, Xiong L, Yao L, Pan J, Arzola E, Zhu X, Mei L, Xiong WC. Attenuation of Alzheimer's brain pathology in 5XFAD mice by PTH 1-34, a peptide of parathyroid hormone. Alzheimers Res Ther 2023; 15:53. [PMID: 36918976 PMCID: PMC10012528 DOI: 10.1186/s13195-023-01202-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2022] [Accepted: 03/06/2023] [Indexed: 03/16/2023]
Abstract
BACKGROUND Alzheimer's disease (AD) and osteoporosis are two distinct diseases but often occur in the same patient. Their relationship remains poorly understood. Studies using Tg2576 AD animal model demonstrate bone deficits, which precede the brain phenotypes by several months, arguing for the independence of bone deficits on brain degeneration and raising a question if the bone deficits contribute to the AD development. To address this question, we investigated the effects of PTH1-34, a peptide of parathyroid hormone analog and a well-recognized effective anabolic therapy drug for patients with osteoporosis, on 5XFAD animal model. METHODS 5XFAD mice, an early onset β-amyloid (Aβ)-based AD mouse model, were treated with PTH1-34 intermittently [once daily injection of hPTH1-34 (50 μg/Kg), 5 days/week, starting at 2-month old (MO) for 2-3 month]. Wild type mice (C57BL/6) were used as control. The bone phenotypes were examined by microCT and evaluated by measuring serum bone formation and resorption markers. The AD relevant brain pathology (e.g., Aβ and glial activation) and behaviors were assessed by a combination of immunohistochemical staining analysis, western blots, and behavior tests. Additionally, systemic and brain inflammation were evaluated by serum cytokine array, real-time PCR (qPCR), and RNAscope. RESULTS A reduced trabecular, but not cortical, bone mass, accompanied with a decrease in bone formation and an increase in bone resorption, was detected in 5XFAD mice at age of 5/6-month old (MO). Upon PTH1-34 treatments, not only these bone deficits but also Aβ-associated brain pathologies, including Aβ and Aβ deposition levels, dystrophic neurites, glial cell activation, and brain inflammatory cytokines, were all diminished; and the cognitive function was improved. Further studies suggest that PTH1-34 acts on not only osteoblasts in the bone but also astrocytes in the brain, suppressing astrocyte senescence and expression of inflammatory cytokines in 5XFAD mice. CONCLUSIONS These results suggest that PTH1-34 may act as a senolytic-like drug, reducing systemic and brain inflammation and improving cognitive function, and implicate PTH1-34's therapeutic potential for patients with not only osteoporosis but also AD.
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Affiliation(s)
- Li Chen
- Department of Neurosciences, School of Medicine, Case Western Reserve University, 2210 Circle Dr, Cleveland, OH, 44106, USA.,Institute of Cytology and Genetics, Northeast Normal University, Changchun, Jilin, China
| | - Lei Xiong
- Department of Neurosciences, School of Medicine, Case Western Reserve University, 2210 Circle Dr, Cleveland, OH, 44106, USA.,Louis Stokes Cleveland Veterans Affairs Medical Center, Cleveland, OH, USA
| | - Lingling Yao
- Department of Neurosciences, School of Medicine, Case Western Reserve University, 2210 Circle Dr, Cleveland, OH, 44106, USA
| | - Jinxiu Pan
- Department of Neurosciences, School of Medicine, Case Western Reserve University, 2210 Circle Dr, Cleveland, OH, 44106, USA.,Louis Stokes Cleveland Veterans Affairs Medical Center, Cleveland, OH, USA
| | - Emily Arzola
- Department of Neurosciences, School of Medicine, Case Western Reserve University, 2210 Circle Dr, Cleveland, OH, 44106, USA
| | - Xiaojuan Zhu
- Institute of Cytology and Genetics, Northeast Normal University, Changchun, Jilin, China
| | - Lin Mei
- Department of Neurosciences, School of Medicine, Case Western Reserve University, 2210 Circle Dr, Cleveland, OH, 44106, USA.,Louis Stokes Cleveland Veterans Affairs Medical Center, Cleveland, OH, USA
| | - Wen-Cheng Xiong
- Department of Neurosciences, School of Medicine, Case Western Reserve University, 2210 Circle Dr, Cleveland, OH, 44106, USA. .,Louis Stokes Cleveland Veterans Affairs Medical Center, Cleveland, OH, USA.
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3
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Grossi JRA, Deliberador TM, Giovanini AF, Zielak JC, Sebstiani AM, Gonzaga CC, Coelho PG, Zétola AL, Weiss FP, Benalcázar Jalkh EB, Storrer CLM, Witek L. Effects of local single dose administration of parathormone on the early stages of osseointegration: A pre-clinical study. J Biomed Mater Res B Appl Biomater 2022; 110:1806-1813. [PMID: 35218605 DOI: 10.1002/jbm.b.35038] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2021] [Revised: 12/27/2021] [Accepted: 02/09/2022] [Indexed: 11/06/2022]
Abstract
The present study aimed to evaluate the effect of parathormone (PTH) administered directly to the implant's surface prior to insertion, using a large translational animal model. Sixty titanium implants were divided into four groups: (i) Collagen, control group, where implants were coated with Type-I Bovine-collagen, and three experimental groups, where implants received varying doses of PTH: (ii) 12.5, (iii) 25, and (iv) 50 μg, prior to placement. Fifteen female sheep (~2 years old, weighing ~65 kg) received four implants in an interpolated fashion in C3, C4 or C5 vertebral bodies. After 3-, 6- and 12-weeks, samples were harvested, histologically processed, qualitatively and quantitatively assessed for bone-to-implant contact (BIC) and bone area fraction occupancy (BAFO). BIC yielded lower values at 6-weeks for 50 μg relative to the control group, with no significant differences, when compared to the 12.5- and 25-μg. No significant differences were detected at 6-weeks between collagen, 12.5- and 25-μg groups. At 3- and 12-weeks, no differences were detected for BIC among PTH groups. With respect to BAFO, no significant differences were observed between the control and experimental groups independent of PTH concentration and time in vivo. Qualitative observations at 3-weeks indicated the presence of a more mature bone near the implant's surface with the application of PTH, however, no significant differences in new bone formation or healing patterns were observed at 6- and 12-weeks. Single local application of different concentrations of PTH on titanium implant's surface did not influence the osseointegration at any time-point evaluation in low-density bone.
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Affiliation(s)
| | | | | | - João César Zielak
- School of Health Sciences, Graduate Program in Dentistry, Universidade Positivo, Curitiba, Paraná, Brazil
| | | | - Carla Castiglia Gonzaga
- School of Health Sciences, Graduate Program in Dentistry, Universidade Positivo, Curitiba, Paraná, Brazil
| | - Paulo G Coelho
- Department of Biomaterials, New York University College of Dentistry, New York, New York, USA.,Hansjörg Wyss Department of Plastic Surgery, New York University Langone Medical Center, New York, New York, USA.,Department of Mechanical and Aerospace Engineering, New York University Tandon School of Engineering, Brooklyn, New York, USA
| | - André Luis Zétola
- Department of Oral and Maxillofacial Surgery, Universidade Positivo, Curitiba, Paraná, Brazil
| | - Fernando P Weiss
- Department of Biomaterials, New York University College of Dentistry, New York, New York, USA
| | - Ernesto B Benalcázar Jalkh
- Department of Biomaterials, New York University College of Dentistry, New York, New York, USA.,Department of Prosthodontics and Periodontology, University of São Paulo - Bauru School of Dentistry, Bauru, São Paulo, Brazil
| | | | - Lukasz Witek
- Department of Biomaterials, New York University College of Dentistry, New York, New York, USA.,Department of Biomedical Engineering, New York University Tandon School of Engineering, Brooklyn, New York, USA
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4
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Brent MB, Lodberg A, Bromer FD, van der Eerden BCJ, Eijken M, Brüel A, Thomsen JS. Activin type IIA decoy receptor and intermittent parathyroid hormone in combination overturns the bone loss in disuse-osteopenic mice. Bone 2021; 142:115692. [PMID: 33069923 DOI: 10.1016/j.bone.2020.115692] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/19/2020] [Revised: 09/25/2020] [Accepted: 10/09/2020] [Indexed: 12/17/2022]
Abstract
Damage of the lower motor neuron cell bodies or their axons results in reduced or abolished voluntary movement accompanied by a substantial loss of bone and muscle mass. Intermittent parathyroid hormone 1-34 (PTH) (teriparatide) is one of the most potent bone-anabolic treatment regimens. ActRIIA-mFc is an activin type IIA decoy receptor that increases bone mass mediated by inhibition of the activin receptor signaling pathway. We investigated whether PTH or ActRIIA-mFc alone or in combination could prevent loss of bone and muscle mass induced by injecting botulinum toxin A (BTX) into the right hind limb in mice. Seventy-two 16-week-old female C57BL/6 mice were allocated to the following groups: Baseline, Control, BTX, BTX + ActRIIA-mFc (10 mg/kg), BTX + PTH (100 μg/kg), and BTX + ActRIIA-mFc + PTH. The mice were sacrificed after three weeks of disuse and treatment. In contrast to monotherapy with PTH, ActRIIA-mFc alone or in combination with PTH was able partly or completely to prevent disuse-induced loss of whole femoral bone mass, trabecular thickness, and bone strength. Moreover, an additive effect of ActRIIA-mFc and PTH on areal bone mineral density and trabecular bone volume was found. In summary, ActRIIA-mFc and PTH in combination were more effective in preventing disuse-induced bone loss and deterioration of trabecular micro-architecture than either treatment alone.
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Affiliation(s)
| | | | | | - Bram C J van der Eerden
- Department of Internal Medicine, Erasmus University Medical Center, Rotterdam, the Netherlands
| | - Marco Eijken
- Department of Clinical Medicine, Aarhus University, Aarhus, Denmark
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5
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Pal S, Porwal K, Khanna K, Gautam MK, Malik MY, Rashid M, Macleod RJ, Wahajuddin M, Parameswaran V, Bellare JR, Chattopadhyay N. Oral dosing of pentoxifylline, a pan-phosphodiesterase inhibitor restores bone mass and quality in osteopenic rabbits by an osteogenic mechanism: A comparative study with human parathyroid hormone. Bone 2019; 123:28-38. [PMID: 30858147 DOI: 10.1016/j.bone.2019.03.010] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/29/2018] [Revised: 03/06/2019] [Accepted: 03/08/2019] [Indexed: 10/27/2022]
Abstract
The non-selective phosphodiesterase inhibitor pentoxifylline (PTX) is used for the treatment of intermittent claudication due to artery occlusion. Previous studies in rodents have reported salutary effects of the intraperitoneal administration of PTX in segmental bone defect and fracture healing, as well as stimulation of bone formation. We determined the effect of orally dosed PTX in skeletally mature ovariectomized (OVX) rabbits with osteopenia. The half-maximal effective concentration (EC50) of PTX in rabbit bone marrow stromal cells was 3.07 ± 1.37 nM. The plasma PTX level was 2.05 ± 0.522 nM after a single oral dose of 12.5mg/kg, which was one-sixth of the adult human dose of PTX. Four months of daily oral dosing of PTX at 12.5 mg/kg to osteopenic rabbits completely restored bone mineral density, bone mineral content (BMC), microarchitecture and bone strength to the level of the sham-operated (ovary intact) group. The bone strength to BMC relationship between PTX and sham was similar. The bone restorative effect of PTX was observed in both axial and appendicular bones. In osteopenic rabbits, PTX increased serum amino-terminal propeptide, mineralized nodule formation by stromal cells and osteogenic gene expression in bone. PTX reversed decreased calcium weight percentage and poor crystal packing found in osteopenic rabbits. Furthermore, similar to parathyroid hormone (PTH), PTX had no effect on bone resorption. Taken together, our data show that PTX completely restored bone mass, bone strength and bone mineral properties by an anabolic mechanism. PTX has the potential to become an oral osteogenic drug for the treatment of post-menopausal osteoporosis.
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Affiliation(s)
- Subhashis Pal
- Division of Endocrinology, CSIR-Central Drug Research Institute, Council of Scientific and Industrial Research, Lucknow 226031, India
| | - Konica Porwal
- Division of Endocrinology, CSIR-Central Drug Research Institute, Council of Scientific and Industrial Research, Lucknow 226031, India
| | - Kunal Khanna
- Department of Chemical Engineering, Indian Institute of Technology-Bombay, Mumbai 400076, India
| | - Manoj Kumar Gautam
- Department of Mechanical Engineering, Indian Institute of Technology-Kanpur, Kanpur 208016, India
| | | | - Mamunur Rashid
- Division of Pharmaceutics, CDRI-CSIR, Lucknow 226031, India
| | - R John Macleod
- Department of Biomedical and Molecular Sciences, Queen's University, Kingston, Ontario, Canada
| | | | | | - Jayesh R Bellare
- Department of Chemical Engineering, Indian Institute of Technology-Bombay, Mumbai 400076, India
| | - Naibedya Chattopadhyay
- Division of Endocrinology, CSIR-Central Drug Research Institute, Council of Scientific and Industrial Research, Lucknow 226031, India.
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6
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Polyzos SA, Duntas L, Bollerslev J. The intriguing connections of leptin to hyperparathyroidism. Endocrine 2017; 57:376-387. [PMID: 28730419 DOI: 10.1007/s12020-017-1374-6] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/02/2017] [Accepted: 07/05/2017] [Indexed: 12/14/2022]
Abstract
PURPOSE Leptin has been implicated in bone metabolism, but the association with parathyroid gland function has not been fully clarified. This review aimed to summarize evidence of the association between leptin and hyperparathyroidism, both primary and secondary, elucidating the potential pathophysiologic and therapeutic consequences between leptin and parathyroid hormone, hopefully prompting the design of new studies. RESULTS Experimental studies indicate a positive loop between leptin and parathyroid hormone in primary hyperparathyroidism. Dissimilar, parathyroid hormone seems to inhibit leptin expression in severe secondary hyperparathyroidism. Data from clinical studies indicate higher leptin levels in patients with primary hyperparathyroidism than controls, but no association between parathyroid hormone and leptin levels, as well as a minimal or neutral effect of parathyroidectomy on leptin levels in patients with primary hyperparathyroidism. Clinical data on secondary hyperparathyroidism, mainly derived from patients with chronic kidney disease, indicate a potential inverse association between leptin and parathyroid hormone in some, but not all studies. This relationship may be affected by the diversity of morbidity among these patients. CONCLUSIONS Data from experimental studies suggest a different association between leptin and parathyroid hormone in primary and secondary hyperparathyroidism. Data from clinical studies are conflicting and potentially affected by confounders. More focused, well-designed studies are warranted to elucidate a potential association between leptin and parathyroid hormone, which may have specific clinical implications, i.e., targeting obesity and hyperleptinemia in patients with hyperparathyroidism.
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MESH Headings
- Adipose Tissue, White/drug effects
- Adipose Tissue, White/metabolism
- Animals
- Anti-Obesity Agents/therapeutic use
- Chief Cells, Gastric/drug effects
- Chief Cells, Gastric/metabolism
- Hormone Replacement Therapy
- Humans
- Hyperparathyroidism, Primary/complications
- Hyperparathyroidism, Primary/drug therapy
- Hyperparathyroidism, Primary/metabolism
- Hyperparathyroidism, Primary/physiopathology
- Hyperparathyroidism, Secondary/complications
- Hyperparathyroidism, Secondary/drug therapy
- Hyperparathyroidism, Secondary/metabolism
- Hyperparathyroidism, Secondary/physiopathology
- Insulin Resistance
- Leptin/blood
- Leptin/genetics
- Leptin/metabolism
- Leptin/therapeutic use
- Models, Biological
- Obesity/blood
- Obesity/complications
- Obesity/drug therapy
- Obesity/metabolism
- Parathyroid Glands/drug effects
- Parathyroid Glands/physiopathology
- Parathyroid Hormone/blood
- Parathyroid Hormone/genetics
- Parathyroid Hormone/metabolism
- Parathyroid Hormone/therapeutic use
- Recombinant Proteins/therapeutic use
- Reproducibility of Results
- Severity of Illness Index
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Affiliation(s)
- Stergios A Polyzos
- First Department of Pharmacology, School of Medicine, Aristotle University of Thessaloniki, Thessaloniki, Greece.
| | - Leonidas Duntas
- Endocrine Unit, Evgenidion Hospital, University of Athens, Athens, Greece
| | - Jens Bollerslev
- Section of Specialized Endocrinology, Medical Clinic B, Oslo University Hospital, Oslo, Norway
- Faculty of Medicine, University in Oslo, Oslo, Norway
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7
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Dede AD, Makras P, Anastasilakis AD. Investigational anabolic agents for the treatment of osteoporosis: an update on recent developments. Expert Opin Investig Drugs 2017; 26:1137-1144. [DOI: 10.1080/13543784.2017.1371136] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Affiliation(s)
- Anastasia D Dede
- Department of Endocrinology and Diabetes, Chelsea and Westminster Hospital, London, UK
- Laboratory for Research of the Musculoskeletal System ‘Th. Garofalidis,’ KAT Hospital, Medical School, Athens, Greece
| | - Polyzois Makras
- Department of Endocrinology and Diabetes, 251 Hellenic Air Force & VA General Hospital, Athens, Greece
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8
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Abstract
PURPOSE OF REVIEW The purpose is to review the efficacy and optimal use of parathyroid hormone and parathyroid hormone-related protein analogs in osteoporosis treatment. RECENT FINDINGS The parathyroid hormone analog teriparatide, a potent stimulator of bone remodeling, increases hip and spine bone mineral density and reduces the risk of vertebral and non-vertebral fractures in postmenopausal osteoporotic women. The parathyroid hormone-related protein analog, abaloparatide, also reduces fracture incidence but has pharmacological effects that differ from teriparatide, particularly in cortical bone. These analogs provide maximal benefit when their use is followed by a potent antiresorptive medication. Moreover, studies have shown that the combination of teriparatide and the RANK-ligand inhibitor, denosumab, increase bone density and estimated strength more than monotherapy and more than any currently available regimen. Parathyroid hormone and parathyroid hormone-related protein analogs, whether as monotherapy, in combination with antiresorptive agents or in sequence with antiresorptive agents, will likely play an expanding role in osteoporosis management.
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Affiliation(s)
- Benjamin Z Leder
- Harvard Medical School, Endocrine Unit, Massachusetts General Hospital, Boston, USA.
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9
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Guo J, Khatri A, Maeda A, Potts JT, Jüppner H, Gardella TJ. Prolonged Pharmacokinetic and Pharmacodynamic Actions of a Pegylated Parathyroid Hormone (1-34) Peptide Fragment. J Bone Miner Res 2017; 32:86-98. [PMID: 27428040 PMCID: PMC5199614 DOI: 10.1002/jbmr.2917] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/12/2016] [Revised: 06/17/2016] [Accepted: 06/27/2016] [Indexed: 11/05/2022]
Abstract
Polyethylene glycol (PEG) addition can prolong the pharmacokinetic and pharmacodynamic actions of a bioactive peptide in vivo, in part by impeding rates of glomerular filtration. For parathyroid hormone (PTH) peptides, pegylation could help in exploring the actions of the hormone in the kidney; e.g., in dissecting the relative roles that filtered versus blood-borne PTH play in regulating phosphate transport. It could also lead to potential alternate forms of treatment for hypoparathyroidism. We thus synthesized the fluorescent pegylated PTH derivative [Lys13 (tetramethylrhodamine {TMR}), Cys35 (PEG-20,000 Da)]PTH(1-35) (PEG-PTHTMR ) and its non-pegylated counterpart [Lys13 (TMR), Cys35 ]PTH(1-35) (PTHTMR ) and assessed their properties in cells and in mice. In PTHR1-expressing HEK-293 cells, PEG-PTHTMR and PTHTMR exhibited similar potencies for inducing cAMP signaling, whereas when injected into mice, the pegylated analog persisted much longer in the circulation (>24 hours versus ∼ 1 hour) and induced markedly more prolonged calcemic and phosphaturic responses than did the non-pegylated control. Fluorescence microscopy analysis of kidney sections obtained from the injected mice revealed much less PEG-PTHTMR than PTHTMR on the luminal brush-border surfaces of renal proximal tubule cells (PTCs), on which PTH regulates phosphate transporter function, whereas immunostained phosphorylated PKA substrate, a marker of cAMP signaling, was increased to similar extents for the two ligands and for each, was localized to the basolateral portion of the PTCs. Pegylation of a bioactive PTH peptide thus led to prolonged pharmacokinetic/pharmacodynamic properties in vivo, as well as to new in vivo data that support a prominent role for PTH action at basolateral surfaces of renal proximal tubule cells. © 2016 American Society for Bone and Mineral Research.
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Affiliation(s)
- Jun Guo
- Endocrine Unit, Massachusetts General Hospital, and Harvard Medical School, Boston, MA, USA
| | - Ashok Khatri
- Endocrine Unit, Massachusetts General Hospital, and Harvard Medical School, Boston, MA, USA
| | - Akira Maeda
- Endocrine Unit, Massachusetts General Hospital, and Harvard Medical School, Boston, MA, USA
| | - John T Potts
- Endocrine Unit, Massachusetts General Hospital, and Harvard Medical School, Boston, MA, USA
| | - Harald Jüppner
- Endocrine Unit, Massachusetts General Hospital, and Harvard Medical School, Boston, MA, USA
| | - Thomas J Gardella
- Endocrine Unit, Massachusetts General Hospital, and Harvard Medical School, Boston, MA, USA
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10
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Abstract
Abaloparatide is an investigational analog of human PTHrP (1-34) being developed for the treatment of osteoporosis. The amino-acid sequence of abaloparatide is identical to that of PTHrP in the first 20 amino-acids, while over half of the remaining amino-acids are different. Some studies in animals and in humans reported that abaloparatide presented a potent anabolic activity with reduced effects on bone resorption as compared to that observed with teriparatide. This may be due to a more transient signaling response of abaloparatide related to differing affinities of the two drugs to the specific conformations of the PTH1 receptor. In the ACTIVE study, a phase 3 fracture prevention trial, 2460 postmenopausal osteoporotic women at high risk for fracture were randomized to receive 18-months of either daily abaloparatide 80 μg s.c., placebo or teriparatide 20 μg s.c. The reduction in vertebral fracture rate with respect to placebo was 86% in the abaloparatide group and 80% in the teriparatide group. Abaloparatide also produced a significant 43% reduction in the rate of nonvertebral fractures (2.7 vs 4.0% with placebo, p=0.04) whereas teriparatide determined a 28% reduction (2.9 vs 4.0% with placebo, p=NS). Abaloparatide or teriparatide showed similar increases in BMD at lumbar spine, while the patients of the abaloparatide group showed significantly greater increases in BMD at both total hip (4.18 vs 3.26%) and femoral neck (3.60 vs 2.66%). Therefore, if the preliminary data of the ACTIVE study is confirmed, abaloparatide may become an important option for the anabolic treatment of postmenopausal osteoporosis.
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Affiliation(s)
- Stefano Gonnelli
- Department of Medicine, Surgery and Neuroscience, University of Siena, Siena, Italy
| | - Carla Caffarelli
- Department of Medicine, Surgery and Neuroscience, University of Siena, Siena, Italy
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11
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Wootten D, Miller LJ, Koole C, Christopoulos A, Sexton PM. Allostery and Biased Agonism at Class B G Protein-Coupled Receptors. Chem Rev 2016; 117:111-138. [PMID: 27040440 DOI: 10.1021/acs.chemrev.6b00049] [Citation(s) in RCA: 77] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Class B G protein-coupled receptors (GPCRs) respond to paracrine or endocrine peptide hormones involved in control of bone homeostasis, glucose regulation, satiety, and gastro-intestinal function, as well as pain transmission. These receptors are targets for existing drugs that treat osteoporosis, hypercalcaemia, Paget's disease, type II diabetes, and obesity and are being actively pursued as targets for numerous other diseases. Exploitation of class B receptors has been limited by difficulties with small molecule drug discovery and development and an under appreciation of factors governing optimal therapeutic efficacy. Recently, there has been increasing awareness of novel attributes of GPCR function that offer new opportunity for drug development. These include the presence of allosteric binding sites on the receptor that can be exploited as drug binding pockets and the ability of individual drugs to enrich subpopulations of receptor conformations to selectively control signaling, a phenomenon termed biased agonism. In this review, current knowledge of biased signaling and small molecule allostery within class B GPCRs is discussed, highlighting areas that have progressed significantly over the past decade, in addition to those that remain largely unexplored with respect to these phenomena.
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Affiliation(s)
- Denise Wootten
- Drug Discovery Biology and Department of Pharmacology, Monash Institute of Pharmaceutical Sciences, Monash University , Parkville 3052, Victoria, Australia
| | - Laurence J Miller
- Department of Molecular Pharmacology and Experimental Therapeutics, Mayo Clinic , Scottsdale, Arizona 85259, United States
| | - Cassandra Koole
- Drug Discovery Biology and Department of Pharmacology, Monash Institute of Pharmaceutical Sciences, Monash University , Parkville 3052, Victoria, Australia.,Laboratory of Chemical Biology and Signal Transduction, The Rockefeller University , New York, New York 10065, United States
| | - Arthur Christopoulos
- Drug Discovery Biology and Department of Pharmacology, Monash Institute of Pharmaceutical Sciences, Monash University , Parkville 3052, Victoria, Australia
| | - Patrick M Sexton
- Drug Discovery Biology and Department of Pharmacology, Monash Institute of Pharmaceutical Sciences, Monash University , Parkville 3052, Victoria, Australia
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12
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Esbrit P, Herrera S, Portal-Núñez S, Nogués X, Díez-Pérez A. Parathyroid Hormone-Related Protein Analogs as Osteoporosis Therapies. Calcif Tissue Int 2016; 98:359-69. [PMID: 26259869 DOI: 10.1007/s00223-015-0050-1] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/02/2015] [Accepted: 08/03/2015] [Indexed: 12/14/2022]
Abstract
The only bone anabolic agent currently available for osteoporosis treatment is parathyroid hormone (PTH)-either its N-terminal 1-34 fragment or the whole molecule of 1-84 aminoacids-whose intermittent administration stimulates new bone formation by targeting osteoblastogenesis and osteoblast survival. PTH-related protein (PTHrP) is an abundant factor in bone which shows N-terminal homology with PTH and thus exhibits high affinity for the same PTH type 1 receptor in osteoblasts. Therefore, it is not surprising that intermittently administered N-terminal PTHrP peptides induce bone anabolism in animals and humans. Furthermore, the C-terminal region of PTHrP also elicits osteogenic features in vitro in osteoblastic cells and in various animal models of osteoporosis. In this review, we discuss the current concepts about the cellular and molecular mechanisms whereby PTHrP may induce anabolic actions in bone. Pre-clinical studies and clinical data using N-terminal PTHrP analogs are also summarized, pointing to PTHrP as a promising alternative to current bone anabolic therapies.
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Affiliation(s)
- Pedro Esbrit
- Laboratorio de Metabolismo Mineral y Óseo, Instituto de Investigación Sanitaria (IIS)-Fundación Jiménez Díaz, Avda. Reyes Católicos, 2, 28040, Madrid, Spain.
- Universidad Autónoma de Madrid, Madrid, Spain.
- Red Temática de Investigación Cooperativa en Envejecimiento y Fragilidad (RETICEF), Instituto de Salud Carlos III, Madrid, Spain.
| | - Sabina Herrera
- Hospital del Mar-IMIM, Universidad Autónoma de Barcelona, Barcelona, Spain
- Red Temática de Investigación Cooperativa en Envejecimiento y Fragilidad (RETICEF), Instituto de Salud Carlos III, Madrid, Spain
| | - Sergio Portal-Núñez
- Laboratorio de Metabolismo Mineral y Óseo, Instituto de Investigación Sanitaria (IIS)-Fundación Jiménez Díaz, Avda. Reyes Católicos, 2, 28040, Madrid, Spain
- Universidad Autónoma de Madrid, Madrid, Spain
- Red Temática de Investigación Cooperativa en Envejecimiento y Fragilidad (RETICEF), Instituto de Salud Carlos III, Madrid, Spain
| | - Xavier Nogués
- Hospital del Mar-IMIM, Universidad Autónoma de Barcelona, Barcelona, Spain
- Red Temática de Investigación Cooperativa en Envejecimiento y Fragilidad (RETICEF), Instituto de Salud Carlos III, Madrid, Spain
| | - Adolfo Díez-Pérez
- Hospital del Mar-IMIM, Universidad Autónoma de Barcelona, Barcelona, Spain
- Red Temática de Investigación Cooperativa en Envejecimiento y Fragilidad (RETICEF), Instituto de Salud Carlos III, Madrid, Spain
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13
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Quinlan E, Thompson EM, Matsiko A, O'Brien FJ, López-Noriega A. Functionalization of a Collagen-Hydroxyapatite Scaffold with Osteostatin to Facilitate Enhanced Bone Regeneration. Adv Healthc Mater 2015; 4:2649-56. [PMID: 26414944 DOI: 10.1002/adhm.201500439] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2015] [Revised: 07/30/2015] [Indexed: 01/05/2023]
Abstract
Defects within bones caused by trauma and other pathological complications may often require the use of a range of therapeutics to facilitate tissue regeneration. A number of approaches have been widely utilized for the delivery of such therapeutics via physical encapsulation or chemical immobilization suggesting significant promise in the healing of bone defects. The study focuses on the chemical immobilization of osteostatin, a pentapeptide of the parathyroid hormone (PTHrP107-111), within a collagen-hydroxyapatite scaffold. The chemical attachment method via crosslinking supports as little as 4% release of the peptide from the scaffolds after 21 d whereas non-crosslinking leads to 100% of the peptide being released by as early as 4 d. In vitro characterization demonstrates that this cross-linking method of immobilization supports a pro-osteogenic effect on osteoblasts. Most importantly, when implanted in a critical-sized calvarial defect within a rat, these scaffolds promote significantly greater new bone volume and area compared to nonfunctionalized scaffolds (**p < 0.01) and an empty defect control (***p < 0.001). Collectively, this study suggests that such an approach of chemical immobilization offers greater spatiotemporal control over growth factors and can significantly modulate tissue regeneration. Such a system may be adopted for a range of different proteins and thus offers the potential for the treatment of various complex pathologies that require localized mediation of drug delivery.
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Affiliation(s)
- Elaine Quinlan
- Tissue Engineering Research Group; Department of Anatomy; Royal College of Surgeons in Ireland; Dublin 2 Ireland
- Trinity Centre for Bioengineering; Trinity College Dublin; Dublin 2 Ireland
- Advanced Materials and Bioengineering Research (AMBER) Centre; RCSI & TCD; Dublin 2 Ireland
| | - Emmet M. Thompson
- Tissue Engineering Research Group; Department of Anatomy; Royal College of Surgeons in Ireland; Dublin 2 Ireland
- Trinity Centre for Bioengineering; Trinity College Dublin; Dublin 2 Ireland
- Advanced Materials and Bioengineering Research (AMBER) Centre; RCSI & TCD; Dublin 2 Ireland
| | - Amos Matsiko
- Tissue Engineering Research Group; Department of Anatomy; Royal College of Surgeons in Ireland; Dublin 2 Ireland
- Trinity Centre for Bioengineering; Trinity College Dublin; Dublin 2 Ireland
- Advanced Materials and Bioengineering Research (AMBER) Centre; RCSI & TCD; Dublin 2 Ireland
| | - Fergal J. O'Brien
- Tissue Engineering Research Group; Department of Anatomy; Royal College of Surgeons in Ireland; Dublin 2 Ireland
- Trinity Centre for Bioengineering; Trinity College Dublin; Dublin 2 Ireland
- Advanced Materials and Bioengineering Research (AMBER) Centre; RCSI & TCD; Dublin 2 Ireland
| | - Adolfo López-Noriega
- Tissue Engineering Research Group; Department of Anatomy; Royal College of Surgeons in Ireland; Dublin 2 Ireland
- Trinity Centre for Bioengineering; Trinity College Dublin; Dublin 2 Ireland
- Advanced Materials and Bioengineering Research (AMBER) Centre; RCSI & TCD; Dublin 2 Ireland
- School of Pharmacy; Royal College of Surgeons in Ireland; Dublin 2 Ireland
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14
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Cheloha RW, Gellman SH, Vilardaga JP, Gardella TJ. PTH receptor-1 signalling-mechanistic insights and therapeutic prospects. Nat Rev Endocrinol 2015; 11:712-24. [PMID: 26303600 PMCID: PMC4651712 DOI: 10.1038/nrendo.2015.139] [Citation(s) in RCA: 145] [Impact Index Per Article: 16.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Parathyroid hormone/parathyroid hormone-related protein receptor (PTH/PTHrP type 1 receptor; commonly known as PTHR1) is a family B G-protein-coupled receptor (GPCR) that regulates skeletal development, bone turnover and mineral ion homeostasis. PTHR1 transduces stimuli from PTH and PTHrP into the interior of target cells to promote diverse biochemical responses. Evaluation of the signalling properties of structurally modified PTHR1 ligands has helped to elucidate determinants of receptor function and mechanisms of downstream cellular and physiological responses. Analysis of PTHR1 responses induced by structurally modified ligands suggests that PTHR1 can continue to signal through a G-protein-mediated pathway within endosomes. Such findings challenge the longstanding paradigm in GPCR biology that the receptor is transiently activated at the cell membrane, followed by rapid deactivation and receptor internalization. Evaluation of structurally modified PTHR1 ligands has further led to the identification of ligand analogues that differ from PTH or PTHrP in the type, strength and duration of responses induced at the receptor, cellular and organism levels. These modified ligands, and the biochemical principles revealed through their use, might facilitate an improved understanding of PTHR1 function in vivo and enable the treatment of disorders resulting from defects in PTHR1 signalling. This Review discusses current understanding of PTHR1 modes of action and how these findings might be applied in future therapeutic agents.
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Affiliation(s)
- Ross W Cheloha
- Department of Chemistry, 1101 University Avenue, University of Wisconsin, Madison, WI 53706, USA
| | - Samuel H Gellman
- Department of Chemistry, 1101 University Avenue, University of Wisconsin, Madison, WI 53706, USA
| | - Jean-Pierre Vilardaga
- Laboratory for GPCR Biology, Department of Pharmacology and Chemical Biology, University of Pittsburgh School of Medicine, 200 Lothrop Street, Pittsburgh, PA 15213, USA
| | - Thomas J Gardella
- Endocrine Unit, Massachusetts General Hospital, 50 Blossom Street, Boston, MA 02114, USA
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15
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Makras P, Delaroudis S, Anastasilakis AD. Novel therapies for osteoporosis. Metabolism 2015; 64:1199-214. [PMID: 26277199 DOI: 10.1016/j.metabol.2015.07.011] [Citation(s) in RCA: 59] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/25/2015] [Revised: 07/02/2015] [Accepted: 07/06/2015] [Indexed: 12/28/2022]
Abstract
Since the identification of osteoporosis as a major health issue in aging populations and the subsequent development of the first treatment modalities for its management, considerable progress has been made in our understanding of the mechanisms controlling bone turnover and disease pathophysiology, thus enabling the pinpointing of new targets for intervention. This progress, along with advances in biotechnology, has rendered possible the development of ever more sophisticated treatments employing novel mechanisms of action. Denosumab, a monoclonal antibody against RANKL, approved for the treatment of postmenopausal and male osteoporosis, significantly and continuously increases bone mineral density (BMD) and maintains a low risk of vertebral, non-vertebral, and hip fractures for up to 8 years. Currently available combinations of estrogens with selective estrogen receptor modulators moderately increase BMD without causing the extra-skeletal adverse effects of each compound alone. The cathepsin K inhibitor odanacatib has recently been shown to decrease vertebral, non-vertebral, and hip fracture rates and is nearing approval. Romosozumab, an anti-sclerosin antibody, and abaloparatide, a PTH-related peptide analog, are at present in advanced stages of clinical evaluation, so far demonstrating efficaciousness together with a favorable safety profile. Several other agents are currently in earlier clinical and preclinical phases of development, including dickkopf-1 antagonists, activin A antagonists, β-arrestin analogs, calcilytics, and Src tyrosine kinase inhibitors.
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Affiliation(s)
- Polyzois Makras
- Department of Endocrinology and Diabetes, 251 Hellenic Air Force & VA General Hospital, Athens, Greece
| | - Sideris Delaroudis
- Department of Endocrinology, 424 General Military Hospital, Thessaloniki, Greece
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16
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Abstract
Fractures across the stages of chronic kidney disease (CKD) could be due to osteoporosis, some form of renal osteodystrophy defined by specific quantitative histomorphometry or chronic kidney disease-mineral and bone disorder (CKD-MBD). CKD-MBD is a systemic disease that links disorders of mineral and bone metabolism due to CKD to either one or all of the following: abnormalities of calcium, phosphorus, parathyroid hormone or vitamin D metabolism; abnormalities in bone turnover, mineralization, volume, linear growth or strength; or vascular or other soft-tissue calcification. Osteoporosis, as defined by the National Institutes of Health, may coexist with renal osteodystrophy or CKD-MBD. Differentiation among these disorders is required to manage correctly the correct disorder to reduce the risk of fractures. While the World Health Organization (WHO) bone mineral density (BMD) criteria for osteoporosis can be used in patients with stages 1-3 CKD, the disorders of bone turnover become so aberrant by stages 4 and 5 CKD that neither the WHO criteria nor the occurrence of a fragility fracture can be used for the diagnosis of osteoporosis. The diagnosis of osteoporosis in stages 4 and 5 CKD is one of the exclusion-excluding either renal osteodystrophy or CKD-MBD as the cause of low BMD or fragility fractures. Differentiations among the disorders of renal osteodystrophy, CKD-MBD or osteoporosis are dependent on the measurement of specific biochemical markers, including serum parathyroid hormone (PTH) and/or quantitative bone histomorphometry. Management of fractures in stages 1-3 CKD does not differ in persons with or without CKD with osteoporosis assuming that there is no evidence for CKD-MBD, clinically suspected by elevated PTH, hyperphosphatemia or fibroblast growth factor 23 due to CKD. Treatment of fractures in persons with osteoporosis and stages 4 and 5 CKD is not evidence-based, with the exception of post-hoc analysis suggesting efficacy and safety of specific osteoporosis therapies (alendronate, risedronate and denosumab) in stage 4 CKD. This review also discusses how to diagnose and manage fragility fractures across the five stages of CKD.
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Affiliation(s)
- Paul D Miller
- Colorado Center for Bone Research, Lakewood, CO, USA
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