1
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Echevarria-Cruz E, McMillan DW, Reid KF, Valderrábano RJ. Spinal Cord Injury Associated Disease of the Skeleton, an Unresolved Problem with Need for Multimodal Interventions. Adv Biol (Weinh) 2024:e2400213. [PMID: 39074256 DOI: 10.1002/adbi.202400213] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2024] [Revised: 07/11/2024] [Indexed: 07/31/2024]
Abstract
Spinal cord injury is associated with skeletal unloading, sedentary behavior, decreases in skeletal muscle mass, and exercise intolerance, which results in rapid and severe bone loss. To date, monotherapy with physical interventions such as weight-bearing in standing frames, computer-controlled electrically stimulated cycling and ambulation exercise, and low-intensity vibration are unsuccessful in maintaining bone density after SCI. Strategies to maintain bone density with commonly used osteoporosis medications also fail to provide a significant clinical benefit, potentially due to a unique pathology of bone deterioration in SCI. In this review, the available data is discussed on evaluating and monitoring bone loss, fracture, and physical and pharmacological therapeutic approaches to SCI-associated disease of the skeleton. The treatment of SCI-associated disease of the skeleton, the implications for clinical management, and areas of need are considered for future investigation.
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Affiliation(s)
- Evelyn Echevarria-Cruz
- Research Program in Men's Health, Aging and Metabolism, and Boston Claude D. Brigham and Women's Hospital, Harvard Medical School, 221 Longwood Ave Boston, 5th Floor, Boston, MA, 02115, USA
| | - David W McMillan
- The Miami Project to Cure Paralysis, University of Miami Leonard M. Miller School of Medicine, 1611 NW 12th ave, Office 2.141, Miami, FL, 33136, USA
- Department of Neurological Surgery, University of Miami Leonard M. Miller School of Medicine, Miami, FL, 33136, USA
| | - Kieran F Reid
- Research Program in Men's Health, Aging and Metabolism, and Boston Claude D. Brigham and Women's Hospital, Harvard Medical School, 221 Longwood Ave Boston, 5th Floor, Boston, MA, 02115, USA
- Laboratory of Exercise Physiology and Physical Performance, Boston Claude D. Pepper Older Americans Independence Center for Function Promoting Therapies, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, 02115, USA
| | - Rodrigo J Valderrábano
- Research Program in Men's Health, Aging and Metabolism, and Boston Claude D. Brigham and Women's Hospital, Harvard Medical School, 221 Longwood Ave Boston, 5th Floor, Boston, MA, 02115, USA
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2
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Walker V. The Intricacies of Renal Phosphate Reabsorption-An Overview. Int J Mol Sci 2024; 25:4684. [PMID: 38731904 PMCID: PMC11083860 DOI: 10.3390/ijms25094684] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2024] [Revised: 04/17/2024] [Accepted: 04/19/2024] [Indexed: 05/13/2024] Open
Abstract
To maintain an optimal body content of phosphorus throughout postnatal life, variable phosphate absorption from food must be finely matched with urinary excretion. This amazing feat is accomplished through synchronised phosphate transport by myriads of ciliated cells lining the renal proximal tubules. These respond in real time to changes in phosphate and composition of the renal filtrate and to hormonal instructions. How they do this has stimulated decades of research. New analytical techniques, coupled with incredible advances in computer technology, have opened new avenues for investigation at a sub-cellular level. There has been a surge of research into different aspects of the process. These have verified long-held beliefs and are also dramatically extending our vision of the intense, integrated, intracellular activity which mediates phosphate absorption. Already, some have indicated new approaches for pharmacological intervention to regulate phosphate in common conditions, including chronic renal failure and osteoporosis, as well as rare inherited biochemical disorders. It is a rapidly evolving field. The aim here is to provide an overview of our current knowledge, to show where it is leading, and where there are uncertainties. Hopefully, this will raise questions and stimulate new ideas for further research.
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Affiliation(s)
- Valerie Walker
- Department of Clinical Biochemistry, University Hospital Southampton NHS Foundation Trust, Southampton General Hospital, Southampton S016 6YD, UK
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3
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Aydin A, Klenk C, Nemec K, Işbilir A, Martin LM, Zauber H, Rrustemi T, Toka HR, Schuster H, Gong M, Stricker S, Bock A, Bähring S, Selbach M, Lohse MJ, Luft FC. ADAM19 cleaves the PTH receptor and associates with brachydactyly type E. Life Sci Alliance 2024; 7:e202302400. [PMID: 38331475 PMCID: PMC10853454 DOI: 10.26508/lsa.202302400] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2023] [Revised: 01/25/2024] [Accepted: 01/25/2024] [Indexed: 02/10/2024] Open
Abstract
Brachydactyly type E (BDE), shortened metacarpals, metatarsals, cone-shaped epiphyses, and short stature commonly occurs as a sole phenotype. Parathyroid hormone-like protein (PTHrP) has been shown to be responsible in all forms to date, either directly or indirectly. We used linkage and then whole genome sequencing in a small pedigree, to elucidate BDE and identified a truncated disintegrin-and-metalloproteinase-19 (ADAM19) allele in all affected family members, but not in nonaffected persons. Since we had shown earlier that the extracellular domain of the parathyroid hormone receptor (PTHR1) is subject to an unidentified metalloproteinase cleavage, we tested the hypothesis that ADAM19 is a sheddase for PTHR1. WT ADAM19 cleaved PTHR1, while mutated ADAM-19 did not. We mapped the cleavage site that we verified with mass spectrometry between amino acids 64-65. ADAM-19 cleavage increased Gq and decreased Gs activation. Moreover, perturbed PTHR1 cleavage by ADAM19 increased ß-arrestin2 recruitment, while cAMP accumulation was not altered. We suggest that ADAM19 serves as a regulatory element for PTHR1 and could be responsible for BDE. This sheddase may affect other PTHrP or PTH-related functions.
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Affiliation(s)
- Atakan Aydin
- Max Delbrück Center for Molecular Medicine in the Helmholtz Association (MDC), Berlin, Germany
- https://ror.org/001w7jn25 Experimental and Clinical Research Center, A Cooperation Between the Max Delbrück Center for Molecular Medicine in the Helmholtz Association and Charité Universitätsmedizin, Berlin, Germany
| | - Christoph Klenk
- Institute of Pharmacology and Toxicology, University of Würzburg, Würzburg, Germany
| | - Katarina Nemec
- Max Delbrück Center for Molecular Medicine in the Helmholtz Association (MDC), Berlin, Germany
- Institute of Pharmacology and Toxicology, University of Würzburg, Würzburg, Germany
- Department of Structural Biology and Center of Excellence for Data-Driven Discovery, St. Jude Children's Research Hospital, Memphis, TN, USA
| | - Ali Işbilir
- Max Delbrück Center for Molecular Medicine in the Helmholtz Association (MDC), Berlin, Germany
- Institute of Pharmacology and Toxicology, University of Würzburg, Würzburg, Germany
| | - Lisa M Martin
- Max Delbrück Center for Molecular Medicine in the Helmholtz Association (MDC), Berlin, Germany
| | - Henrik Zauber
- Max Delbrück Center for Molecular Medicine in the Helmholtz Association (MDC), Berlin, Germany
| | - Trendelina Rrustemi
- Max Delbrück Center for Molecular Medicine in the Helmholtz Association (MDC), Berlin, Germany
| | - Hakan R Toka
- https://ror.org/001w7jn25 Experimental and Clinical Research Center, A Cooperation Between the Max Delbrück Center for Molecular Medicine in the Helmholtz Association and Charité Universitätsmedizin, Berlin, Germany
| | - Herbert Schuster
- https://ror.org/001w7jn25 Experimental and Clinical Research Center, A Cooperation Between the Max Delbrück Center for Molecular Medicine in the Helmholtz Association and Charité Universitätsmedizin, Berlin, Germany
| | - Maolian Gong
- https://ror.org/001w7jn25 Experimental and Clinical Research Center, A Cooperation Between the Max Delbrück Center for Molecular Medicine in the Helmholtz Association and Charité Universitätsmedizin, Berlin, Germany
| | - Sigmar Stricker
- Institute of Chemistry and Biochemistry, Freie Universität Berlin, Berlin, Germany
| | - Andreas Bock
- Max Delbrück Center for Molecular Medicine in the Helmholtz Association (MDC), Berlin, Germany
- Rudolf-Boehm-Institute of Pharmacology and Toxicology, Medical Faculty, University of Leipzig, Leipzig, Germany
| | - Sylvia Bähring
- https://ror.org/001w7jn25 Experimental and Clinical Research Center, A Cooperation Between the Max Delbrück Center for Molecular Medicine in the Helmholtz Association and Charité Universitätsmedizin, Berlin, Germany
| | - Matthias Selbach
- Max Delbrück Center for Molecular Medicine in the Helmholtz Association (MDC), Berlin, Germany
| | - Martin J Lohse
- Max Delbrück Center for Molecular Medicine in the Helmholtz Association (MDC), Berlin, Germany
- ISAR Bioscience Institute, Munich, Germany
| | - Friedrich C Luft
- Max Delbrück Center for Molecular Medicine in the Helmholtz Association (MDC), Berlin, Germany
- https://ror.org/001w7jn25 Experimental and Clinical Research Center, A Cooperation Between the Max Delbrück Center for Molecular Medicine in the Helmholtz Association and Charité Universitätsmedizin, Berlin, Germany
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4
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Otvos L, Wade JD. Big peptide drugs in a small molecule world. Front Chem 2023; 11:1302169. [PMID: 38144886 PMCID: PMC10740154 DOI: 10.3389/fchem.2023.1302169] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2023] [Accepted: 11/24/2023] [Indexed: 12/26/2023] Open
Abstract
A quarter of a century ago, designer peptide drugs finally broke through the glass ceiling. Despite the resistance by big pharma, biotechnology companies managed to develop injectable peptide-based drugs, first against orphan or other small volume diseases, and later for conditions affecting large patient populations such as type 2 diabetes. Even their lack of gastrointestinal absorption could be utilized to enable successful oral dosing against chronic constipation. The preference of peptide therapeutics over small molecule competitors against identical medical conditions can be achieved by careful target selection, intrachain and terminal amino acid modifications, appropriate conjugation to stability enhancers and chemical space expansion, innovative delivery and administration techniques and patient-focused marketing strategies. Unfortunately, however, pharmacoeconomical considerations, including the strength of big pharma to develop competing small molecule drugs, have somewhat limited the success of otherwise smart peptide-based therapeutics. Yet, with increasing improvement in peptide drug modification and formulation, these are continuing to gain significant, and growing, acceptance as desirable alternatives to small molecule compounds.
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Affiliation(s)
- Laszlo Otvos
- Institute of Medical Microbiology, Semmelweis University, Budapest, Hungary
- OLPE Pharmaceutical Consultants, Audubon, PA, United States
| | - John D. Wade
- Florey Institute of Neuroscience and Mental Health, Parkville, VIC, Australia
- School of Chemistry, University of Melbourne, Parkville, VIC, Australia
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5
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Yu Z, Kreitler DF, Chiu YTT, Xu R, Bruchs AT, Bingman CA, Gellman SH. Harnessing Aromatic-Histidine Interactions through Synergistic Backbone Extension and Side Chain Modification. Angew Chem Int Ed Engl 2023; 62:e202308100. [PMID: 37587780 PMCID: PMC10668598 DOI: 10.1002/anie.202308100] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2023] [Revised: 07/31/2023] [Accepted: 08/14/2023] [Indexed: 08/18/2023]
Abstract
Peptide engineering efforts have delivered drugs for diverse human diseases. Side chain alteration is among the most common approaches to designing new peptides for specific applications. The peptide backbone can be modified as well, but this strategy has received relatively little attention. Here we show that new and favorable contacts between a His side chain on a target protein and an aromatic side chain on a synthetic peptide ligand can be engineered by rational and coordinated side chain modification and backbone extension. Side chain modification alone was unsuccessful. Binding measurements, high-resolution structural studies and pharmacological outcomes all support the synergy between backbone and side chain modification in engineered ligands of the parathyroid hormone receptor-1, which is targeted by osteoporosis drugs. These results should motivate other structure-based designs featuring coordinated side chain modification and backbone extension to enhance the engagement of peptide ligands with target proteins.
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Affiliation(s)
- Zhen Yu
- Department of Chemistry, University of Wisconsin-Madison, Madison, Wisconsin, 53706, USA
| | - Dale F Kreitler
- National Synchrotron Light Source II, Brookhaven National Laboratory, Upton, New York, 11973, USA
| | - Yin Ting T Chiu
- Department of Chemistry, University of Wisconsin-Madison, Madison, Wisconsin, 53706, USA
| | - Ruiwen Xu
- Department of Chemistry, University of Wisconsin-Madison, Madison, Wisconsin, 53706, USA
| | - Austin T Bruchs
- Department of Chemistry, University of Wisconsin-Madison, Madison, Wisconsin, 53706, USA
| | - Craig A Bingman
- Department of Biochemistry, University of Wisconsin-Madison, Madison, Wisconsin, 53706, USA
| | - Samuel H Gellman
- Department of Chemistry, University of Wisconsin-Madison, Madison, Wisconsin, 53706, USA
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6
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Zhao LH, Yuan QN, Dai AT, He XH, Chen CW, Zhang C, Xu YW, Zhou Y, Wang MW, Yang DH, Xu HE. Molecular recognition of two endogenous hormones by the human parathyroid hormone receptor-1. Acta Pharmacol Sin 2023; 44:1227-1237. [PMID: 36482086 PMCID: PMC10203121 DOI: 10.1038/s41401-022-01032-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2022] [Accepted: 11/15/2022] [Indexed: 12/13/2022] Open
Abstract
Parathyroid hormone (PTH) and PTH-related peptide (PTHrP) are two endogenous hormones recognized by PTH receptor-1 (PTH1R), a member of class B G protein- coupled receptors (GPCRs). Both PTH and PTHrP analogs including teriparatide and abaloparatide are approved drugs for osteoporosis, but they exhibit distinct pharmacology. Here we report two cryo-EM structures of human PTH1R bound to PTH and PTHrP in the G protein-bound state at resolutions of 2.62 Å and 3.25 Å, respectively. Detailed analysis of these structures uncovers both common and unique features for the agonism of PTH and PTHrP. Molecular dynamics (MD) simulation together with site-directed mutagenesis studies reveal the molecular basis of endogenous hormones recognition specificity and selectivity to PTH1R. These results provide a rational template for the clinical use of PTH and PTHrP analogs as an anabolic therapy for osteoporosis and other disorders.
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Affiliation(s)
- Li-Hua Zhao
- The CAS Key Laboratory of Receptor Research, Center for Structure and Function of Drug Targets, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, 201203, China.
- University of Chinese Academy of Sciences, Beijing, 100049, China.
| | - Qing-Ning Yuan
- The CAS Key Laboratory of Receptor Research, Center for Structure and Function of Drug Targets, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, 201203, China
| | - An-Tao Dai
- The CAS Key Laboratory of Receptor Research, Center for Structure and Function of Drug Targets, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, 201203, China
- The National Center for Drug Screening, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, 201203, China
| | - Xin-Heng He
- The CAS Key Laboratory of Receptor Research, Center for Structure and Function of Drug Targets, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, 201203, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Chuan-Wei Chen
- Research Center for Deepsea Bioresources, Sanya, 572025, China
| | - Chao Zhang
- School of Pharmacy, Fudan University, Shanghai, 201203, China
| | - You-Wei Xu
- The CAS Key Laboratory of Receptor Research, Center for Structure and Function of Drug Targets, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, 201203, China
| | - Yan Zhou
- The CAS Key Laboratory of Receptor Research, Center for Structure and Function of Drug Targets, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, 201203, China
- The National Center for Drug Screening, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, 201203, China
| | - Ming-Wei Wang
- Research Center for Deepsea Bioresources, Sanya, 572025, China
- Department of Pharmacology, School of Basic Medical Sciences, Fudan University, Shanghai, 200032, China
- Department of Chemistry, School of Science, The University of Tokyo, Tokyo, 113-0033, Japan
| | - De-Hua Yang
- The CAS Key Laboratory of Receptor Research, Center for Structure and Function of Drug Targets, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, 201203, China.
- University of Chinese Academy of Sciences, Beijing, 100049, China.
- The National Center for Drug Screening, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, 201203, China.
| | - H Eric Xu
- The CAS Key Laboratory of Receptor Research, Center for Structure and Function of Drug Targets, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, 201203, China.
- University of Chinese Academy of Sciences, Beijing, 100049, China.
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7
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Kane JF, Johnson RW. Re-Evaluating the Role of PTHrP in Breast Cancer. Cancers (Basel) 2023; 15:2670. [PMID: 37345007 PMCID: PMC10216606 DOI: 10.3390/cancers15102670] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2023] [Revised: 05/02/2023] [Accepted: 05/04/2023] [Indexed: 06/23/2023] Open
Abstract
Parathyroid-hormone-related protein (PTHrP) is a protein with a long history of association with bone metastatic cancers. The paracrine signaling of PTHrP through the parathyroid hormone receptor (PTHR1) facilitates tumor-induced bone destruction, and PTHrP is known as the primary driver of humoral hypercalcemia of malignancy. In addition to paracrine signaling, PTHrP is capable of intracrine signaling independent of PTHR1 binding, which is essential for cytokine-like functions in normal physiological conditions in a variety of tissue types. Pre-clinical and clinical studies evaluating the role of PTHrP in breast cancer have yielded contradictory conclusions, in some cases indicating the protein is tumor suppressive, and in other studies, pro-growth. This review discusses the possible molecular basis for the disharmonious prognostic indications of these studies and highlights the implications of the paracrine, intracrine, and nuclear functions of the protein. This review also examines the current understanding of the functional domains of PTHrP and re-evaluates their role in the unique context of the breast cancer environment. This review will expand on the current understanding of PTHrP by attempting to reconcile the functional domains of the protein with its intracrine signaling in cancer.
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Affiliation(s)
- Jeremy F. Kane
- Program in Cancer Biology, Vanderbilt University, Nashville, TN 37232, USA
- Vanderbilt Center for Bone Biology, Vanderbilt University Medical Center, Nashville, TN 37232, USA
| | - Rachelle W. Johnson
- Program in Cancer Biology, Vanderbilt University, Nashville, TN 37232, USA
- Vanderbilt Center for Bone Biology, Vanderbilt University Medical Center, Nashville, TN 37232, USA
- Division of Clinical Pharmacology, Department of Medicine, Vanderbilt University Medical Center, Nashville, TN 37232, USA
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8
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Vilardaga JP, Clark LJ, White AD, Sutkeviciute I, Lee JY, Bahar I. Molecular Mechanisms of PTH/PTHrP Class B GPCR Signaling and Pharmacological Implications. Endocr Rev 2023; 44:474-491. [PMID: 36503956 PMCID: PMC10461325 DOI: 10.1210/endrev/bnac032] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/13/2022] [Revised: 11/14/2022] [Accepted: 12/05/2022] [Indexed: 12/14/2022]
Abstract
The classical paradigm of G protein-coupled receptor (GPCR) signaling via G proteins is grounded in a view that downstream responses are relatively transient and confined to the cell surface, but this notion has been revised in recent years following the identification of several receptors that engage in sustained signaling responses from subcellular compartments following internalization of the ligand-receptor complex. This phenomenon was initially discovered for the parathyroid hormone (PTH) type 1 receptor (PTH1R), a vital GPCR for maintaining normal calcium and phosphate levels in the body with the paradoxical ability to build or break down bone in response to PTH binding. The diverse biological processes regulated by this receptor are thought to depend on its capacity to mediate diverse modes of cyclic adenosine monophosphate (cAMP) signaling. These include transient signaling at the plasma membrane and sustained signaling from internalized PTH1R within early endosomes mediated by PTH. Here we discuss recent structural, cell signaling, and in vivo studies that unveil potential pharmacological outputs of the spatial versus temporal dimension of PTH1R signaling via cAMP. Notably, the combination of molecular dynamics simulations and elastic network model-based methods revealed how precise modulation of PTH signaling responses is achieved through structure-encoded allosteric coupling within the receptor and between the peptide hormone binding site and the G protein coupling interface. The implications of recent findings are now being explored for addressing key questions on how location bias in receptor signaling contributes to pharmacological functions, and how to drug a difficult target such as the PTH1R toward discovering nonpeptidic small molecule candidates for the treatment of metabolic bone and mineral diseases.
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Affiliation(s)
- Jean-Pierre Vilardaga
- Laboratory for GPCR Biology, Department of Pharmacology and Chemical Biology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15261, USA
| | - Lisa J Clark
- Laboratory for GPCR Biology, Department of Pharmacology and Chemical Biology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15261, USA
| | - Alex D White
- Laboratory for GPCR Biology, Department of Pharmacology and Chemical Biology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15261, USA
| | - Ieva Sutkeviciute
- Laboratory for GPCR Biology, Department of Pharmacology and Chemical Biology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15261, USA
| | - Ji Young Lee
- Department of Computational and Systems Biology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15261, USA
| | - Ivet Bahar
- Department of Computational and Systems Biology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15261, USA
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9
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Cary BP, Gerrard EJ, Belousoff MJ, Fletcher MM, Jiang Y, Russell IC, Piper SJ, Wootten D, Sexton PM. Molecular insights into peptide agonist engagement with the PTH receptor. Structure 2023:S0969-2126(23)00125-9. [PMID: 37148874 DOI: 10.1016/j.str.2023.04.002] [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: 09/06/2022] [Revised: 12/30/2022] [Accepted: 04/03/2023] [Indexed: 05/08/2023]
Abstract
The parathyroid hormone (PTH) 1 receptor (PTH1R) is a G protein-coupled receptor (GPCR) that regulates skeletal development and calcium homeostasis. Here, we describe cryo-EM structures of the PTH1R in complex with fragments of the two hormones, PTH and PTH-related protein, the drug abaloparatide, as well as the engineered tool compounds, long-acting PTH (LA-PTH) and the truncated peptide, M-PTH(1-14). We found that the critical N terminus of each agonist engages the transmembrane bundle in a topologically similar fashion, reflecting similarities in measures of Gαs activation. The full-length peptides induce subtly different extracellular domain (ECD) orientations relative to the transmembrane domain. In the structure bound to M-PTH, the ECD is unresolved, demonstrating that the ECD is highly dynamic when unconstrained by a peptide. High resolutions enabled identification of water molecules near peptide and G protein binding sites. Our results illuminate the action of orthosteric agonists of the PTH1R.
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Affiliation(s)
- Brian P Cary
- Drug Discovery Biology Theme, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville 3052, VIC, Australia; ARC Centre for Cryo-Electron Microscopy of Membrane Proteins, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville 3052, VIC, Australia.
| | - Elliot J Gerrard
- Drug Discovery Biology Theme, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville 3052, VIC, Australia
| | - Matthew J Belousoff
- Drug Discovery Biology Theme, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville 3052, VIC, Australia; ARC Centre for Cryo-Electron Microscopy of Membrane Proteins, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville 3052, VIC, Australia
| | - Madeleine M Fletcher
- Drug Discovery Biology Theme, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville 3052, VIC, Australia
| | - Yan Jiang
- Drug Discovery Biology Theme, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville 3052, VIC, Australia; ARC Centre for Cryo-Electron Microscopy of Membrane Proteins, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville 3052, VIC, Australia
| | - Isabella C Russell
- Drug Discovery Biology Theme, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville 3052, VIC, Australia; ARC Centre for Cryo-Electron Microscopy of Membrane Proteins, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville 3052, VIC, Australia
| | - Sarah J Piper
- Drug Discovery Biology Theme, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville 3052, VIC, Australia; ARC Centre for Cryo-Electron Microscopy of Membrane Proteins, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville 3052, VIC, Australia
| | - Denise Wootten
- Drug Discovery Biology Theme, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville 3052, VIC, Australia; ARC Centre for Cryo-Electron Microscopy of Membrane Proteins, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville 3052, VIC, Australia.
| | - Patrick M Sexton
- Drug Discovery Biology Theme, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville 3052, VIC, Australia; ARC Centre for Cryo-Electron Microscopy of Membrane Proteins, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville 3052, VIC, Australia.
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10
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Cary BP, Zhang X, Cao J, Johnson RM, Piper SJ, Gerrard EJ, Wootten D, Sexton PM. New insights into the structure and function of class B1 GPCRs. Endocr Rev 2022; 44:492-517. [PMID: 36546772 PMCID: PMC10166269 DOI: 10.1210/endrev/bnac033] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/24/2022] [Revised: 11/07/2022] [Accepted: 12/14/2022] [Indexed: 12/24/2022]
Abstract
G protein-coupled receptors (GPCRs) are the largest family of cell surface receptors. Class B1 GPCRs constitute a subfamily of 15 receptors that characteristically contain large extracellular domains (ECDs) and respond to long polypeptide hormones. Class B1 GPCRs are critical regulators of homeostasis, and as such, many are important drug targets. While most transmembrane proteins, including GPCRs, are recalcitrant to crystallization, recent advances in electron cryo-microscopy (cryo-EM) have facilitated a rapid expansion of the structural understanding of membrane proteins. As a testament to this success, structures for all the class B1 receptors bound to G proteins have been determined by cryo-EM in the past five years. Further advances in cryo-EM have uncovered dynamics of these receptors, ligands, and signalling partners. Here, we examine the recent structural underpinnings of the class B1 GPCRs with an emphasis on structure-function relationships.
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Affiliation(s)
- Brian P Cary
- Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, VIC, 3052, Australia.,ARC Centre for Cryo-electron Microscopy of Membrane Proteins, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, VIC, 3052, Australia
| | - Xin Zhang
- Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, VIC, 3052, Australia.,ARC Centre for Cryo-electron Microscopy of Membrane Proteins, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, VIC, 3052, Australia
| | - Jianjun Cao
- Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, VIC, 3052, Australia.,ARC Centre for Cryo-electron Microscopy of Membrane Proteins, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, VIC, 3052, Australia
| | - Rachel M Johnson
- Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, VIC, 3052, Australia.,ARC Centre for Cryo-electron Microscopy of Membrane Proteins, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, VIC, 3052, Australia
| | - Sarah J Piper
- Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, VIC, 3052, Australia.,ARC Centre for Cryo-electron Microscopy of Membrane Proteins, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, VIC, 3052, Australia
| | - Elliot J Gerrard
- Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, VIC, 3052, Australia.,ARC Centre for Cryo-electron Microscopy of Membrane Proteins, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, VIC, 3052, Australia
| | - Denise Wootten
- Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, VIC, 3052, Australia.,ARC Centre for Cryo-electron Microscopy of Membrane Proteins, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, VIC, 3052, Australia
| | - Patrick M Sexton
- Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, VIC, 3052, Australia.,ARC Centre for Cryo-electron Microscopy of Membrane Proteins, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, VIC, 3052, Australia
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11
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Altered signaling at the PTH receptor via modified agonist contacts with the extracellular domain provides a path to prolonged agonism in vivo. Proc Natl Acad Sci U S A 2022; 119:e2212736119. [PMID: 36409914 PMCID: PMC9860328 DOI: 10.1073/pnas.2212736119] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The parathyroid hormone type 1 receptor (PTHR1), a Class B GPCR, is activated by long polypeptides, including drugs for osteoporosis and hypoparathyroidism. The PTHR1 engages peptide agonists via a two-step mechanism. Initial contact involves the extracellular domain (ECD), which has been thought to contribute primarily to receptor-peptide binding, and then the N terminus of the peptide engages the receptor transmembrane domain (TMD), which is thought to control the message conveyed to intracellular partners. This mechanism has been suggested to apply to other Class B GPCRs as well. Here, we show that modification of a PTHR1 agonist at ECD-contact sites can alter the signaling profile, an outcome that is not accommodated by the current two-step binding model. Our data support a modified two-step binding model in which agonist orientation on the ECD surface can influence the geometry of agonist-TMD engagement. This expanded binding model offers a mechanism by which altering ECD-contact residues can affect signaling profile. Our discoveries provide a rationale for exploring agonist modifications distal from the TMD-contact region in future efforts to optimize therapeutic performance of peptide hormone analogs.
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12
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Yu Z, Cary BP, Kim TW, Nguyen KD, Gardella TJ, Gellman SH. Kinetic and Thermodynamic Insights into Agonist Interactions with the Parathyroid Hormone Receptor-1 from a New NanoBRET Assay. ACS Chem Biol 2022; 17:3148-3158. [PMID: 36282520 PMCID: PMC9747329 DOI: 10.1021/acschembio.2c00595] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
Polypeptides that activate the parathyroid hormone receptor-1 (PTHR1) are important in human physiology and medicine. Most previous studies of peptide binding to this receptor have involved the displacement of a radiolabeled ligand. We report a new assay format based on bioluminescence resonance energy transfer (BRET). Fusion of a NanoLuc luciferase (nLuc) unit to the N-terminus of the PTHR1 allows the direct detection of binding by an agonist peptide bearing a tetramethylrhodamine (TMR) unit. Affinity measurements from the BRET assay align well with results previously obtained via radioligand displacement. The BRET assay offers substantial operational benefits relative to affinity measurements involving radioactive compounds. The convenience of the new assay allowed us to explore several questions raised by earlier reports. For example, we show that although the first two residues of PTH(1-34) (the drug teriparatide) are critical for PTHR1 activation, these two residues contribute little or nothing to affinity. Comparisons among the well-studied agonists PTH(1-34), PTHrP(1-34), and "long-acting PTH" (LA-PTH) reveal that the high affinity of LA-PTH arises largely from a diminished rate constant for dissociation relative to the other two. A D-peptide recently reported to be comparable to PTH(1-34) as an agonist of the PTHR1 was found not to bind detectably to the receptor and to be a very weak agonist.
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Affiliation(s)
- Zhen Yu
- Department of Chemistry, University of Wisconsin - Madison, Madison, WI 53706 USA
| | - Brian P. Cary
- Department of Chemistry, University of Wisconsin - Madison, Madison, WI 53706 USA
| | - Tae Wook Kim
- Department of Chemistry, University of Wisconsin - Madison, Madison, WI 53706 USA
| | - Kevin D. Nguyen
- Department of Chemistry, University of Wisconsin - Madison, Madison, WI 53706 USA
| | - Thomas J. Gardella
- Endocrine Unit, Massachusetts General Hospital and Harvard Medical School, Boston, MA 02114 USA
| | - Samuel H. Gellman
- Department of Chemistry, University of Wisconsin - Madison, Madison, WI 53706 USA
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13
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Zhai X, Mao C, Shen Q, Zang S, Shen DD, Zhang H, Chen Z, Wang G, Zhang C, Zhang Y, Liu Z. Molecular insights into the distinct signaling duration for the peptide-induced PTH1R activation. Nat Commun 2022; 13:6276. [PMID: 36271004 PMCID: PMC9586930 DOI: 10.1038/s41467-022-34009-x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2022] [Accepted: 10/06/2022] [Indexed: 02/08/2023] Open
Abstract
The parathyroid hormone type 1 receptor (PTH1R), a class B1 G protein-coupled receptor, plays critical roles in bone turnover and Ca2+ homeostasis. Teriparatide (PTH) and Abaloparatide (ABL) are terms as long-acting and short-acting peptide, respectively, regarding their marked duration distinctions of the downstream signaling. However, the mechanistic details remain obscure. Here, we report the cryo-electron microscopy structures of PTH- and ABL-bound PTH1R-Gs complexes, adapting similar overall conformations yet with notable differences in the receptor ECD regions and the peptide C-terminal portions. 3D variability analysis and site-directed mutagenesis studies uncovered that PTH-bound PTH1R-Gs complexes display less motions and are more tolerant of mutations in affecting the receptor signaling than ABL-bound complexes. Furthermore, we combined the structural analysis and signaling assays to delineate the molecular basis of the differential signaling durations induced by these peptides. Our study deepens the mechanistic understanding of ligand-mediated prolonged or transient signaling.
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Affiliation(s)
- Xiuwen Zhai
- grid.89957.3a0000 0000 9255 8984National Clinical Research Center of Kidney Diseases, Jinling Clinical Medical College of Nanjing Medical University, Nanjing, 211166 Jiangsu China
| | - Chunyou Mao
- grid.13402.340000 0004 1759 700XCenter for Structural Pharmacology and Therapeutics Development, Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, China ,grid.415999.90000 0004 1798 9361Department of General Surgery, Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China
| | - Qingya Shen
- grid.13402.340000 0004 1759 700XLiangzhu Laboratory, Zhejiang University Medical Center, Hangzhou, China
| | - Shaokun Zang
- grid.13402.340000 0004 1759 700XDepartment of Biophysics and Department of Pathology of Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | - Dan-Dan Shen
- grid.13402.340000 0004 1759 700XDepartment of Biophysics and Department of Pathology of Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | - Huibing Zhang
- grid.13402.340000 0004 1759 700XDepartment of Biophysics and Department of Pathology of Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | - Zhaohong Chen
- grid.89957.3a0000 0000 9255 8984National Clinical Research Center of Kidney Diseases, Jinling Clinical Medical College of Nanjing Medical University, Nanjing, 211166 Jiangsu China
| | - Gang Wang
- grid.89957.3a0000 0000 9255 8984National Clinical Research Center of Kidney Diseases, Jinling Clinical Medical College of Nanjing Medical University, Nanjing, 211166 Jiangsu China
| | - Changming Zhang
- grid.89957.3a0000 0000 9255 8984National Clinical Research Center of Kidney Diseases, Jinling Clinical Medical College of Nanjing Medical University, Nanjing, 211166 Jiangsu China
| | - Yan Zhang
- grid.13402.340000 0004 1759 700XCenter for Structural Pharmacology and Therapeutics Development, Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, China ,grid.13402.340000 0004 1759 700XLiangzhu Laboratory, Zhejiang University Medical Center, Hangzhou, China ,grid.13402.340000 0004 1759 700XDepartment of Biophysics and Department of Pathology of Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, China ,grid.13402.340000 0004 1759 700XMOE Frontier Science Center for Brain Research and Brain-Machine Integration, Zhejiang University School of Medicine, Hangzhou, Zhejiang China ,Zhejiang Provincial Key Laboratory of Immunity and Inflammatory diseases, Hangzhou, Zhejiang China
| | - Zhihong Liu
- grid.89957.3a0000 0000 9255 8984National Clinical Research Center of Kidney Diseases, Jinling Clinical Medical College of Nanjing Medical University, Nanjing, 211166 Jiangsu China ,grid.13402.340000 0004 1759 700XLiangzhu Laboratory, Zhejiang University Medical Center, Hangzhou, China
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14
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Kobayashi K, Kawakami K, Kusakizako T, Miyauchi H, Tomita A, Kobayashi K, Shihoya W, Yamashita K, Nishizawa T, Kato HE, Inoue A, Nureki O. Endogenous ligand recognition and structural transition of a human PTH receptor. Mol Cell 2022; 82:3468-3483.e5. [PMID: 35932760 DOI: 10.1016/j.molcel.2022.07.003] [Citation(s) in RCA: 23] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2021] [Revised: 11/07/2021] [Accepted: 07/11/2022] [Indexed: 11/18/2022]
Abstract
Endogenous parathyroid hormone (PTH) and PTH-related peptide (PTHrP) bind to the parathyroid hormone receptor 1 (PTH1R) and activate the stimulatory G-protein (Gs) signaling pathway. Intriguingly, the two ligands have distinct signaling and physiological properties: PTH evokes prolonged Gs activation, whereas PTHrP evokes transient Gs activation with reduced bone-resorption effects. The distinct molecular actions are ascribed to the differences in ligand recognition and dissociation kinetics. Here, we report cryoelectron microscopic structures of six forms of the human PTH1R-Gs complex in the presence of PTH or PTHrP at resolutions of 2.8 -4.1 Å. A comparison of the PTH-bound and PTHrP-bound structures reveals distinct ligand-receptor interactions underlying the ligand affinity and selectivity. Furthermore, five distinct PTH-bound structures, combined with computational analyses, provide insights into the unique and complex process of ligand dissociation from the receptor and shed light on the distinct durations of signaling induced by PTH and PTHrP.
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Affiliation(s)
- Kazuhiro Kobayashi
- Department of Biological Sciences, Graduate School of Science, the University of Tokyo, Bunkyo, Tokyo 113-0033, Japan
| | - Kouki Kawakami
- Graduate School of Pharmaceutical Sciences, Tohoku University, Sendai, Miyagi 980-8578, Japan
| | - Tsukasa Kusakizako
- Department of Biological Sciences, Graduate School of Science, the University of Tokyo, Bunkyo, Tokyo 113-0033, Japan
| | - Hirotake Miyauchi
- Department of Biological Sciences, Graduate School of Science, the University of Tokyo, Bunkyo, Tokyo 113-0033, Japan
| | - Atsuhiro Tomita
- Department of Biological Sciences, Graduate School of Science, the University of Tokyo, Bunkyo, Tokyo 113-0033, Japan
| | - Kan Kobayashi
- Department of Biological Sciences, Graduate School of Science, the University of Tokyo, Bunkyo, Tokyo 113-0033, Japan
| | - Wataru Shihoya
- Department of Biological Sciences, Graduate School of Science, the University of Tokyo, Bunkyo, Tokyo 113-0033, Japan
| | - Keitaro Yamashita
- Department of Biological Sciences, Graduate School of Science, the University of Tokyo, Bunkyo, Tokyo 113-0033, Japan
| | - Tomohiro Nishizawa
- Department of Biological Sciences, Graduate School of Science, the University of Tokyo, Bunkyo, Tokyo 113-0033, Japan
| | - Hideaki E Kato
- Department of Biological Sciences, Graduate School of Science, the University of Tokyo, Bunkyo, Tokyo 113-0033, Japan; Komaba Institute for Science, the University of Tokyo, Meguro, Tokyo 153-8505, Japan; FOREST, Japan Science and Technology Agency, Kawaguchi, Saitama 332-0012, Japan.
| | - Asuka Inoue
- Graduate School of Pharmaceutical Sciences, Tohoku University, Sendai, Miyagi 980-8578, Japan.
| | - Osamu Nureki
- Department of Biological Sciences, Graduate School of Science, the University of Tokyo, Bunkyo, Tokyo 113-0033, Japan.
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15
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Lauth LM, Voigt B, Bhatia T, Machner L, Balbach J, Ott M. Heparin promotes rapid fibrillation of the basic Parathyroid Hormone at physiological pH. FEBS Lett 2022; 596:2928-2939. [PMID: 35903816 DOI: 10.1002/1873-3468.14455] [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: 03/19/2022] [Revised: 06/14/2022] [Accepted: 07/09/2022] [Indexed: 11/06/2022]
Abstract
In acidic secretory granules of mammalian cells, peptide hormones including the parathyroid hormone (PTH) are presumably stored in the form of functional amyloid fibrils. Mature PTH, however, is considerably positively charged in acidic environments, a condition known to impede unassisted self-aggregation into fibrils. Here, we studied the role of the polyanion heparin on promoting fibril formation of PTH. Employing ITC, CD spectroscopy, NMR, SAXS and fluorescence-based assays we could demonstrate that heparin binds PTH with submicromolar affinity and facilitates its conversion into fibrillar seeds, enabling rapid formation of amyloid fibrils under acidic conditions. In absence of heparin, PTH remained in a soluble monomeric state. We suspect that heparin-like surfaces are required in vivo to convert PTH efficiently into fibrillar deposits.
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Affiliation(s)
- Luca M Lauth
- Department of Biochemistry and Biotechnology, Martin-Luther-University, Halle-Wittenberg, Halle, Germany
| | - Bruno Voigt
- Department of Biophysics, Martin-Luther-University Halle-Wittenberg, Halle, Germany
| | - Twinkle Bhatia
- Department of Biochemistry and Biotechnology, Martin-Luther-University, Halle-Wittenberg, Halle, Germany
| | - Lisa Machner
- Department of Molecular Medicine, Martin-Luther-University Halle-Wittenberg, Halle, Germany
| | - Jochen Balbach
- Department of Biophysics, Martin-Luther-University Halle-Wittenberg, Halle, Germany
| | - Maria Ott
- Department of Biochemistry and Biotechnology, Martin-Luther-University, Halle-Wittenberg, Halle, Germany
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16
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Lee S. Peptide ligand interaction with maltose-binding protein tagged to the calcitonin gene-related peptide receptor: The inhibitory role of receptor N-glycosylation. Peptides 2022; 150:170735. [PMID: 35007660 DOI: 10.1016/j.peptides.2022.170735] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/23/2021] [Revised: 12/29/2021] [Accepted: 01/05/2022] [Indexed: 11/21/2022]
Abstract
Calcitonin gene-related peptide (CGRP) and adrenomedullin (AM) are peptide hormones and their receptors play a critical role in migraine progression and blood pressure control, respectively. CGRP and AM receptors are structurally related since they are the complex of the calcitonin receptor-like receptor (CLR) with the different types of receptor activity-modifying protein (RAMP). Several crystal structures of the CGRP and AM receptor extracellular domain (ECD) used maltose-binding protein (MBP) as a tag protein to facilitate crystallization. Unexpectedly, the recent crystal structures of CGRP receptor ECD showed that the N-terminal tag MBP located in proximity of bound/mutated peptide ligands. This study provided evidence that MBP N-terminally tagged to the CGRP receptor ECD formed chemical interaction with the mutated peptide ligands. Interestingly, N-glycosylation of the CGRP receptor ECD was predicted to prevent MBP docking to the mutated peptide ligands. I found that the N-glycosylation of CLR ECD N123 was the most critical for inhibiting MBP interaction with the mutated peptide ligands. The MBP tag protein interaction was also dependent on the sequence of the peptide ligands. In contrast to the CGRP receptor, the MBP tag was not involved in peptide ligand binding at AM receptor ECD. Here, I provided evidence that N-glycosylation of the CGRP receptor ECD inhibited the tag protein interaction suggesting an additional function of N-glycosylation in the MBP-fused CGRP receptor ECD. This study reveals the importance of using tag protein-free versions of the CGRP receptor for the accurate assessment of peptide binding affinity.
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Affiliation(s)
- Sangmin Lee
- Department of Basic Pharmaceutical Sciences, Fred Wilson School of Pharmacy, High Point University, High Point, NC 27268, USA.
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17
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Su S, Cao J, Meng X, Liu R, Vander Ark A, Woodford E, Zhang R, Stiver I, Zhang X, Madaj ZB, Bowman MJ, Wu Y, Xu HE, Chen B, Yu H, Li X. Enzalutamide-induced and PTH1R-mediated TGFBR2 degradation in osteoblasts confers resistance in prostate cancer bone metastases. Cancer Lett 2022; 525:170-178. [PMID: 34752846 PMCID: PMC9669895 DOI: 10.1016/j.canlet.2021.10.042] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2021] [Revised: 10/28/2021] [Accepted: 10/29/2021] [Indexed: 01/30/2023]
Abstract
Enzalutamide resistance has been observed in approximately 50% of patients with prostate cancer (PCa) bone metastases. Therefore, there is an urgent need to investigate the mechanisms and develop strategies to overcome resistance. We observed enzalutamide resistance in bone lesion development induced by PCa cells in mouse models. We found that the bone microenvironment was indispensable for enzalutamide resistance because enzalutamide significantly inhibited the growth of subcutaneous C4-2B tumors and the proliferation of C4-2B cells isolated from the bone lesions, and the resistance was recapitulated only when C4-2B cells were co-cultured with osteoblasts. In revealing how osteoblasts contribute to enzalutamide resistance, we found that enzalutamide decreased TGFBR2 protein expression in osteoblasts, which was supported by clinical data. This decrease was possibly through PTH1R-mediated endocytosis. We showed that PTH1R blockade rescued enzalutamide-mediated decrease in TGFBR2 levels and enzalutamide responses in C4-2B cells that were co-cultured with osteoblasts. This is the first study to reveal the contribution of the bone microenvironment to enzalutamide resistance and identify PTH1R as a feasible target to overcome the resistance in PCa bone metastases.
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Affiliation(s)
- Shang Su
- Center for Cancer and Cell Biology, Van Andel Institute, Grand Rapids, MI, 49503;,Current address: Department of Cancer Biology, the University of Toledo, Toledo, OH, 43614
| | - Jingchen Cao
- Center for Cancer and Cell Biology, Van Andel Institute, Grand Rapids, MI, 49503
| | - Xiangqi Meng
- Center for Cancer and Cell Biology, Van Andel Institute, Grand Rapids, MI, 49503;,Current address: The Sixth Affiliated Hospital of Sun Yat-sen University, Guangzhou, 510655, China
| | - Ruihua Liu
- Center for Cancer and Cell Biology, Van Andel Institute, Grand Rapids, MI, 49503;,Current address: Department of Cancer Biology, the University of Toledo, Toledo, OH, 43614;,Inner Mongolia University, Hohhot, 010021, China
| | - Alexandra Vander Ark
- Center for Cancer and Cell Biology, Van Andel Institute, Grand Rapids, MI, 49503
| | - Erica Woodford
- Center for Cancer and Cell Biology, Van Andel Institute, Grand Rapids, MI, 49503
| | - Reian Zhang
- Center for Cancer and Cell Biology, Van Andel Institute, Grand Rapids, MI, 49503;,University of Michigan, Ann Arbor, MI, 48109
| | - Isabelle Stiver
- Center for Cancer and Cell Biology, Van Andel Institute, Grand Rapids, MI, 49503;,University of Michigan, Ann Arbor, MI, 48109
| | - Xiaotun Zhang
- Anatomic/Clinical Pathology, Mayo Clinic, Rochester, MN, 55905
| | - Zachary B. Madaj
- Bioinformatics & Biostatistics Core, Van Andel Institute, Grand Rapids, MI, 49503
| | - Megan J. Bowman
- Center for Cancer and Cell Biology, Van Andel Institute, Grand Rapids, MI, 49503;,Current address: Ball Horticultural Company, West Chicago, IL, 60185
| | - Yingying Wu
- Department of Pediatrics and Human Development, College of Human Medicine, Michigan State University, Grand Rapids, MI, 49503;,Current address: Center of Mathematical Sciences and Applications, Harvard University, Cambridge, MA 02138
| | - H. Eric Xu
- Center for Cancer and Cell Biology, Van Andel Institute, Grand Rapids, MI, 49503;,Current address: Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, 201203, China
| | - Bin Chen
- Department of Pediatrics and Human Development, College of Human Medicine, Michigan State University, Grand Rapids, MI, 49503
| | - Haiquan Yu
- Inner Mongolia University, Hohhot, 010021, China
| | - Xiaohong Li
- Center for Cancer and Cell Biology, Van Andel Institute, Grand Rapids, MI, 49503;,Current address: Department of Cancer Biology, the University of Toledo, Toledo, OH, 43614;,Corresponding author: Xiaohong Li, the University of Toledo, 3000 Transverse Drive, Toledo, OH 43614. Phone: +1-419-383-3982;
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18
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Li M, Li M, Guo J. Molecular Mechanism of Ca 2+ in the Allosteric Regulation of Human Parathyroid Hormone Receptor-1. J Chem Inf Model 2021; 62:5110-5119. [PMID: 34464108 DOI: 10.1021/acs.jcim.1c00471] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Parathyroid hormone (PTH) is an endogenous ligand that activates the PTH type 1 receptor (PTH1R) signaling. Ca2+, a common second messenger, acts as an allosteric regulator for prolonging the activation of PTH1R. However, a clear picture of the underlying allosteric mechanism is still missing. Herein, extensive molecular dynamics (MD) simulations are performed for PTH1R-PTH complexes with and without Ca2+ ions, allowing us to delineate the molecular details of calcium-induced allostery. Our results indicate that acidic residues in the extracellular loop 1 (ECL1) (D251, E252, E254, and E258-E260) and PTH (E19 and E22) serve as key determinants for local Ca2+-coupling structures and rigidity of ECL1. Moreover, the binding of Ca2+ induces conformational changes of transmembrane domain 6/7 (TM6/7) that are related to PTH1R activation and strengthens the residue-residue communication within PTH and TMD allosterically. Moreover, our results demonstrate that the presence of Ca2+ ions potentiates the interaction between PTH and PTH1R via steered molecular dynamics (SMD) simulations, while the point mutation in the PTH (PTHR25C) weakens the binding of PTH and PTH1R. These results support that Ca2+ ions might further prolong the residence time of PTH on PTH1R and facilitate the positive allostery of PTH1R. Together, the present work provides new insights into the allosteric regulation mechanism of GPCRs induced by ions and related drug design targeting the PTH1R allosteric pathway.
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Affiliation(s)
- Mengrong Li
- College of Life Sciences, Nanjing Agricultural University, Nanjing 210095, China
| | - Miaomiao Li
- College of Life Sciences, Nanjing Agricultural University, Nanjing 210095, China
| | - Jingjing Guo
- College of Life Sciences, Nanjing Agricultural University, Nanjing 210095, China
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19
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Dharmapradita MW, Suyasa IK, Karna MB, Sumadi IWJ, Giri KGB, Pemayun CKD, Santosa C. High Expression of Parathyroid Hormone-related Protein and Tumor Necrosis Factor-α in Cancer Cells as Risk Factors for Hypercalcemia in Bone Metastases Lytic Lesions. Open Access Maced J Med Sci 2021. [DOI: 10.3889/oamjms.2021.5951] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
Abstract
BACKGROUND: Cancer mortality is more commonly due to metastases of the tumor to other organs and the complications that accompany it than the tumor growth itself. Until recently, metastasis has been an insurmountable problem.
AIM: As the most frequent site of metastases, apart from the lungs and liver, tumor metastases to bone are associated with hypercalcemia which is fatal for the affected patient.
METHODS: This study used a case-control study design. The case group consisted of paraffin block samples derived from bone metastatic cancer cell biopsies of patients with hypercalcemic lytic lesions. The control group consisted of paraffin block samples derived from bone metastatic cancer cell biopsies of patients with non-hypercalcemic lytic lesions. Radiological examination was performed to examine the presence of lytic lesions, followed by data collection of serum calcium levels. The data obtained from the histopathological examination was confirmed along with the availability of paraffin blocks of bone metastasis cancer cell biopsy samples, and immunohistochemical analysis was performed to determine the expression of tumor necrosis factor-α _(TNF-α) and parathyroid hormone-related protein (PTHrP). A Mann–Whitney test was performed to determine the expression of TNF-α _and PTHrP between hypercalcemia and non-hypercalcemia groups. To identify the cut-off point, Youden index on receiver operating characteristic was used, then the optimal cut-off point was determined where the sensitivity and specificity curves intersect. Analysis of risk factor assessment was done by creating a 2 × 2 cross-tabulations and calculating the association size in the form of odds ratio (OR).
RESULTS: The expression of PTHrP and TNF-α _in the case group was significantly different from the control group with p < 0.05. The cut-off point for PTHrP expression was 267.5 with an area under the curve of 0.93, indicating a high accuracy value. The cut-off point for TNF-α _expression was 227.5 with an area under the curve of 0.68, indicating a moderate accuracy value. The OR between hypercalcemia and non-hypercalcemia to PTHrP expression was 110.3 (Fisher’s exact statistical test obtained p < 0.05), while the OR between hypercalcemia and non-hypercalcemia to TNF-α _expression was 7.27 (Fisher’s exact test statistical obtained p = 0.01).
CONCLUSION: Significant differences in the expression of PTHrP and TNF-α _were found between patients with bone metastases lytic lesions with hypercalcemia compared to those without hypercalcemia. We can conclude that either a high level of PTHrP expression and/or TNF-α _expression in cancer cells can serve as risk factors for hypercalcemia in patients with bone metastatic lytic lesions.
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20
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Brent MB, Stoltenborg FE, Brüel A, Thomsen JS. Teriparatide and Abaloparatide Have a Similar Effect on Bone in Mice. Front Endocrinol (Lausanne) 2021; 12:628994. [PMID: 33953694 PMCID: PMC8092394 DOI: 10.3389/fendo.2021.628994] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/13/2020] [Accepted: 03/17/2021] [Indexed: 12/18/2022] Open
Abstract
Three bone anabolic pharmaceuticals are currently approved for treatment of osteoporosis, teriparatide (PTH (1-34)), the parathyroid hormone-related protein analog abaloparatide (ABL), and romosozumab. The present study compared the effect of intermittent PTH (1-34) and ABL on bone tissue directly mole-to-mole in female mice. Forty-seven C57BL/6 mice were randomly allocated to the following groups: Baseline (n = 11), Control (Ctrl) (n = 12), PTH (n = 12), and ABL (n = 12). The mice were injected s.c. with PTH (100 µg/kg), ABL (96 µg/kg), or saline (Ctrl) five days a week for three weeks. To assess the effect of PTH and ABL, the hindlimb bones were analyzed with DXA, µCT, mechanical testing, dynamic bone histomorphometry, and histological quantification of bone cells. In addition, serum calcium concentration was determined. PTH and ABL significantly increased femoral areal bone mineral density (aBMD) (borderline significant p = 0.06 for PTH), femoral mid-diaphyseal bone strength, femoral metaphyseal and epiphyseal and vertebral bone volume fraction (BV/TV), connectivity density, volumetric bone mineral density (vBMD), and bone formation rate (BFR/BS) compared to Ctrl. In addition, ABL also significantly increased mid-diaphyseal cortical thickness and bone area compared to Ctrl. Neither PTH nor ABL significantly increased bone strength at the femoral neck. In conclusion, abaloparatide and PTH have similar bone anabolic properties when compared directly mole-to-mole in mice.
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Affiliation(s)
- Mikkel Bo Brent
- Department of Biomedicine, Aarhus University, Aarhus, Denmark
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21
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Structural Biology for the Molecular Insight between Aptamers and Target Proteins. Int J Mol Sci 2021; 22:ijms22084093. [PMID: 33920991 PMCID: PMC8071422 DOI: 10.3390/ijms22084093] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2021] [Revised: 04/12/2021] [Accepted: 04/14/2021] [Indexed: 02/07/2023] Open
Abstract
Aptamers are promising therapeutic and diagnostic agents for various diseases due to their high affinity and specificity against target proteins. Structural determination in combination with multiple biochemical and biophysical methods could help to explore the interacting mechanism between aptamers and their targets. Regrettably, structural studies for aptamer–target interactions are still the bottleneck in this field, which are facing various difficulties. In this review, we first reviewed the methods for resolving structures of aptamer–protein complexes and for analyzing the interactions between aptamers and target proteins. We summarized the general features of the interacting nucleotides and residues involved in the interactions between aptamers and proteins. Challenges and perspectives in current methodologies were discussed. Approaches for determining the binding affinity between aptamers and target proteins as well as modification strategies for stabilizing the binding affinity of aptamers to target proteins were also reviewed. The review could help to understand how aptamers interact with their targets and how alterations such as chemical modifications in the structures affect the affinity and function of aptamers, which could facilitate the optimization and translation of aptamers-based theranostics.
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22
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Ryan BA, Kovacs CS. Maternal and fetal vitamin D and their roles in mineral homeostasis and fetal bone development. J Endocrinol Invest 2021; 44:643-659. [PMID: 32772256 DOI: 10.1007/s40618-020-01387-2] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/12/2020] [Accepted: 08/02/2020] [Indexed: 01/11/2023]
Abstract
During pregnancy, female physiology adapts to meet the additional mineral demands of the developing fetus. Meanwhile, the fetus actively transports minerals across the placenta and maintains high circulating levels to mineralize the rapidly developing skeleton. Most of this mineral is accreted during the last trimester, including 30 g of calcium, 20 g of phosphate and 0.8 g of magnesium. Given the dependence of calcium homeostasis on vitamin D and calcitriol in the adult and child, it may be expected that vitamin D sufficiency would be even more critical during pregnancy and fetal development. However, the pregnant mother and fetus appear to meet their mineral needs independent of vitamin D. Adaptations in maternal mineral and bone metabolism during pregnancy appear to be invoked independent of maternal vitamin D, while fetal mineral metabolism and skeletal development appear to be protected from vitamin D deficiency and genetic disorders of vitamin D physiology. This review discusses key data from both animal models and human studies to address our current knowledge on the role of vitamin D and calcitriol during pregnancy and fetal development.
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Affiliation(s)
- B A Ryan
- Faculty of Medicine - Endocrinology, Health Sciences Centre, Memorial University of Newfoundland, 300 Prince Philip Drive, St. John's, NL, A1B 3V6, Canada
| | - C S Kovacs
- Faculty of Medicine - Endocrinology, Health Sciences Centre, Memorial University of Newfoundland, 300 Prince Philip Drive, St. John's, NL, A1B 3V6, Canada.
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Nestor JJ, Wang W. Surfactant‐modified parathyroid hormone fragments with high potency and prolonged action: Structure‐informed design using glycolipid surfactant conjugation. Pept Sci (Hoboken) 2021. [DOI: 10.1002/pep2.24225] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Affiliation(s)
| | - Wei Wang
- CS Bio Co Menlo Park California USA
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24
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Todd VM, Johnson RW. Hypoxia in bone metastasis and osteolysis. Cancer Lett 2020; 489:144-154. [PMID: 32561416 PMCID: PMC7429356 DOI: 10.1016/j.canlet.2020.06.004] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2020] [Revised: 05/15/2020] [Accepted: 06/01/2020] [Indexed: 12/19/2022]
Abstract
Hypoxia is a common feature in tumors, driving pathways that promote epithelial-to-mesenchymal transition, invasion, and metastasis. Clinically, high levels of hypoxia-inducible factor (HIF) expression and stabilization at the primary site in many cancer types is associated with poor patient outcomes. Experimental evidence suggests that HIF signaling in the primary tumor promotes their dissemination to the bone, as well as the release of factors such as LOX that act distantly on the bone to stimulate osteolysis and form a pre-metastatic niche. Additionally, the bone itself is a generally hypoxic organ, fueling the activation of HIF signaling in bone resident cells, promoting tumor cell homing to the bone as well as osteoclastogenesis. The hypoxic microenvironment of the bone also stimulates the vicious cycle of tumor-induced bone destruction, further fueling tumor cell growth and osteolysis. Furthermore, hypoxia appears to regulate key tumor dormancy factors. Thus, hypoxia acts both on the tumor cells as well as the metastatic site to promote tumor cell metastasis.
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Affiliation(s)
- Vera M Todd
- Graduate Program in Cancer Biology, Vanderbilt University, Nashville, TN, USA; Vanderbilt Center for Bone Biology, Department of Medicine, Division of Clinical Pharmacology, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Rachelle W Johnson
- Graduate Program in Cancer Biology, Vanderbilt University, Nashville, TN, USA; Vanderbilt Center for Bone Biology, Department of Medicine, Division of Clinical Pharmacology, Vanderbilt University Medical Center, Nashville, TN, USA; Department of Medicine, Division of Clinical Pharmacology, Vanderbilt University Medical Center, Nashville, TN, USA.
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25
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Noda H, Okazaki M, Joyashiki E, Tamura T, Kawabe Y, Khatri A, Jueppner H, Potts JT, Gardella TJ, Shimizu M. Optimization of PTH/PTHrP Hybrid Peptides to Derive a Long-Acting PTH Analog (LA-PTH). JBMR Plus 2020; 4:e10367. [PMID: 32666018 PMCID: PMC7340446 DOI: 10.1002/jbm4.10367] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/20/2020] [Accepted: 04/13/2020] [Indexed: 11/07/2022] Open
Abstract
Prolonged signaling at the parathyroid hormone receptor 1 (PTHR1) correlates with the capacity of a ligand to bind to a G protein‐independent receptor conformation (R0). As long‐acting PTH (LA‐PTH) ligands hold interest as potential treatments for hypoparathyroidism (HP), we explored the structural basis in the ligand for stable R0 binding and prolonged cAMP signaling. A series of PTH/PTHrP hybrid analogs were synthesized and tested for actions in vitro and in vivo. Of the series, [Ala1,3,12,Gln10,Arg11,Trp14]‐PTH(1‐14)/PTHrP(15–36) (M‐PTH/PTHrP) bound with high affinity to R0, induced prolonged cAMP responses in UMR106 rat osteoblast‐derived cells, and induced the most prolonged increases in serum calcium (sCa) in normal rats. Daily s.c. injection of M‐PTH/PTHrP into thyroparathyroidectomized (TPTX) rats, a model of HP, normalized sCa without raising urine Ca. In contrast, oral alfacalcidol, a widely used treatment for HP, normalized sCa, but induced frank hypercalciuria. M‐PTH/PTHrP exhibited low solubility in aqueous solutions of neutral pH; however, replacement of Leu18, Phe22, and His26 with the less hydrophobic residues, Ala, Ala, and Lys, at those respective positions markedly improved solubility while maintaining bioactivity. Indeed, we recently showed that the resultant analog [Ala18,22,Lys26]‐M‐PTH/PTHrP or LA‐PTH, effectively normalizes sCa in TPTX rats and mediates prolonged actions in monkeys. These studies provide useful information for optimizing PTH and PTHrP ligand analogs for therapeutic development. © 2020 The Authors. JBMR Plus published by Wiley Periodicals, Inc. on behalf of American Society for Bone and Mineral Research.
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Affiliation(s)
- Hiroshi Noda
- Research Division Chugai Pharmaceutical Co., Ltd Shizuoka Japan
| | - Makoto Okazaki
- Research Division Chugai Pharmaceutical Co., Ltd Shizuoka Japan.,Endocrine Unit Massachusetts General Hospital Boston MA USA
| | - Eri Joyashiki
- Research Division Chugai Pharmaceutical Co., Ltd Shizuoka Japan
| | - Tatsuya Tamura
- Research Division Chugai Pharmaceutical Co., Ltd Shizuoka Japan
| | - Yoshiki Kawabe
- Research Division Chugai Pharmaceutical Co., Ltd Shizuoka Japan
| | - Ashok Khatri
- Endocrine Unit Massachusetts General Hospital Boston MA USA
| | | | - John T Potts
- Endocrine Unit Massachusetts General Hospital Boston MA USA
| | | | - Masaru Shimizu
- Research Division Chugai Pharmaceutical Co., Ltd Shizuoka Japan
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26
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Brent MB, Thomsen JS, Brüel A. The Efficacy of PTH and Abaloparatide to Counteract Immobilization-Induced Osteopenia Is in General Similar. Front Endocrinol (Lausanne) 2020; 11:588773. [PMID: 33162940 PMCID: PMC7581786 DOI: 10.3389/fendo.2020.588773] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/29/2020] [Accepted: 09/22/2020] [Indexed: 01/02/2023] Open
Abstract
Immobilization results in a substantial bone loss and increased fracture risk. Powerful bone anabolic therapies are necessary to counteract the bone loss and reduce fracture risk during periods with immobilization. Intermittent parathyroid hormone 1-34 (PTH) (teriparatide) and PTH related peptide analog abaloparatide (ABL) are potent bone anabolic therapies acting through the same receptor, but induce different durations of signaling response. We investigated the efficacy of PTH or ABL in preventing immobilization-induced bone loss in rats in a direct mole-to-mole comparison. Immobilization was achieved by injecting botulinum toxin type A (BTX) into the right hindlimb musculature. Sixty 14-week-old female Wistar rats were allocated to the following groups: Baseline, Control, BTX, BTX + PTH (80 μg/kg/day), and BTX + ABL (77 μg/kg/day). Immobilization resulted in a substantial and significant reduction in bone mineral density (aBMD), metaphyseal and epiphyseal trabecular bone volume fraction (BV/TV) and trabecular thickness (Tb.Th), metaphyseal trabecular number (Tb.N), and femoral neck bone strength. Both PTH and ABL prevented the immobilization-induced decrease in aBMD, metaphyseal and epiphyseal Tb.Th, and metaphyseal Tb.N. In addition, PTH rescued the reduction in metaphyseal BV/TV and femoral neck strength, while ABL did not. However, the effect of PTH and ABL did not differ significantly for serum calcium, aBMD, metaphyseal, and epiphyseal BV/TV, Tb.Th, or Tb.N. In conclusion, in a mole-to-mole comparison the efficacy of PTH and ABL is similar in counteracting immobilization-induced reduction in bone mineral density, deterioration in trabecular microarchitecture, and decrease in bone strength.
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27
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Sutkeviciute I, Clark LJ, White AD, Gardella TJ, Vilardaga JP. PTH/PTHrP Receptor Signaling, Allostery, and Structures. Trends Endocrinol Metab 2019; 30:860-874. [PMID: 31699241 PMCID: PMC6857722 DOI: 10.1016/j.tem.2019.07.011] [Citation(s) in RCA: 45] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/31/2019] [Revised: 07/09/2019] [Accepted: 07/12/2019] [Indexed: 02/08/2023]
Abstract
The parathyroid hormone (PTH) type 1 receptor (PTHR) is the canonical G protein-coupled receptor (GPCR) for PTH and PTH-related protein (PTHrP) and the key regulator of calcium homeostasis and bone turnover. PTHR function is critical for human health to maintain homeostatic control of ionized serum Ca2+ levels and has several unusual signaling features, such as endosomal cAMP signaling, that are well-studied but not structurally understood. In this review, we discuss how recently solved high resolution near-atomic structures of hormone-bound PTHR in its inactive and active signaling states and discovery of extracellular Ca2+ allosterism shed light on the structural basis for PTHR signaling and function.
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Affiliation(s)
- Ieva Sutkeviciute
- Laboratory for GPCR Biology, Department of Pharmacology and Chemical Biology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15261, USA
| | - Lisa J Clark
- Laboratory for GPCR Biology, Department of Pharmacology and Chemical Biology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15261, USA; Graduate Program in Molecular Biophysics and Structural Biology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15261, USA
| | - Alex D White
- Laboratory for GPCR Biology, Department of Pharmacology and Chemical Biology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15261, USA; Graduate Program in Molecular Pharmacology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15261, USA
| | - Thomas J Gardella
- Endocrine Unit, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA
| | - Jean-Pierre Vilardaga
- Laboratory for GPCR Biology, Department of Pharmacology and Chemical Biology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15261, USA.
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28
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Modulation of PTH1R signaling by an ECD binding antibody results in inhibition of β-arrestin 2 coupling. Sci Rep 2019; 9:14432. [PMID: 31594997 PMCID: PMC6783463 DOI: 10.1038/s41598-019-51016-z] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2019] [Accepted: 09/24/2019] [Indexed: 02/05/2023] Open
Abstract
Parathyroid hormone receptor 1 (PTH1R) belongs to the secretin class of G protein coupled receptors (GPCRs) and natively binds parathyroid hormone (PTH) and parathyroid hormone related peptide (PTHrP). Ligand binding to PTH1R involves binding to the large extracellular domain (ECD) and the orthosteric pocket, inducing conformational changes in the transmembrane domain and receptor activation. PTH1R regulates bone metabolism, signaling mainly through Gs and Gq/11 G-proteins. Here, we used phage display to generate PTH1R ECD-specific antibodies with the aim of modulating receptor functionality. We identified ECD-scFvhFc, which exhibited high affinity binding to both the isolated ECD and to the full-length receptor in styrene-maleic acid (SMA) lipid particles. Epitope mapping using hydrogen-deuterium exchange mass spectrometry (HDX-MS) indicates that the α1 helix of the ECD is ECD-scFvhFc’s epitope which may partially overlap with the known PTH (1–34) binding site. However, PTH (1–34)-mediated Gs activation is Undisturbed by ECD-scFvhFc binding. In contrast, ECD-scFvhFc potently inhibits β-arrestin-2 recruitment after PTH (1–34)-driven receptor activation and thus represents the first monoclonal antibody to selectively inhibit distinct PTH1R signaling pathways. Given the complexity of PTH1R signaling and the emerging importance of biased GPCR activation in drug development, ECD-scFvhFc could be a valuable tool to study PTH1R signaling bias.
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29
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Bhardwaj N, Singh YP, Mandal BB. Silk Fibroin Scaffold-Based 3D Co-Culture Model for Modulation of Chondrogenesis without Hypertrophy via Reciprocal Cross-talk and Paracrine Signaling. ACS Biomater Sci Eng 2019; 5:5240-5254. [DOI: 10.1021/acsbiomaterials.9b00573] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Nandana Bhardwaj
- Department of Biotechnology, National Institute of Pharmaceutical Education and Research Guwahati, Guwahati 781125, India
| | - Yogendra Pratap Singh
- Biomaterial and Tissue Engineering Laboratory, Department of Biosciences and Bioengineering, Indian Institute of Technology Guwahati, Guwahati 781039, India
| | - Biman B. Mandal
- Biomaterial and Tissue Engineering Laboratory, Department of Biosciences and Bioengineering, Indian Institute of Technology Guwahati, Guwahati 781039, India
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30
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Bhattacharyya S, Pal S, Chattopadhyay N. Abaloparatide, the second generation osteoanabolic drug: Molecular mechanisms underlying its advantages over the first-in-class teriparatide. Biochem Pharmacol 2019; 166:185-191. [DOI: 10.1016/j.bcp.2019.05.024] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2019] [Accepted: 05/23/2019] [Indexed: 12/20/2022]
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31
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Frieling JS, Lynch CC. Proteolytic Regulation of Parathyroid Hormone-Related Protein: Functional Implications for Skeletal Malignancy. Int J Mol Sci 2019; 20:ijms20112814. [PMID: 31181800 PMCID: PMC6600663 DOI: 10.3390/ijms20112814] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2019] [Revised: 05/31/2019] [Accepted: 06/04/2019] [Indexed: 01/17/2023] Open
Abstract
Parathyroid hormone-related protein (PTHrP), with isoforms ranging from 139 to 173 amino acids, has long been implicated in the development and regulation of multiple tissues, including that of the skeleton, via paracrine and autocrine signaling. PTHrP is also known as a potent mediator of cancer-induced bone disease, contributing to a vicious cycle between tumor cells and the bone microenvironment that drives the formation and progression of metastatic lesions. The abundance of roles ascribed to PTHrP have largely been attributed to the N-terminal 1-36 amino acid region, however, activities for mid-region and C-terminal products as well as additional shorter N-terminal species have also been described. Studies of the protein sequence have indicated that PTHrP is susceptible to post-translational proteolytic cleavage by multiple classes of proteases with emerging evidence pointing to novel functional roles for these PTHrP products in regulating cell behavior in homeostatic and pathological contexts. As a consequence, PTHrP products are also being explored as potential biomarkers of disease. Taken together, our enhanced understanding of the post-translational regulation of PTHrP bioactivity could assist in developing new therapeutic approaches that can effectively treat skeletal malignancies.
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Affiliation(s)
- Jeremy S Frieling
- Tumor Biology Department, H. Lee Moffitt Cancer Center and Research Institute, Tampa, FL 33612, USA.
| | - Conor C Lynch
- Tumor Biology Department, H. Lee Moffitt Cancer Center and Research Institute, Tampa, FL 33612, USA.
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32
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Zhao LH, Ma S, Sutkeviciute I, Shen DD, Zhou XE, de Waal PW, Li CY, Kang Y, Clark LJ, Jean-Alphonse FG, White AD, Yang D, Dai A, Cai X, Chen J, Li C, Jiang Y, Watanabe T, Gardella TJ, Melcher K, Wang MW, Vilardaga JP, Xu HE, Zhang Y. Structure and dynamics of the active human parathyroid hormone receptor-1. Science 2019; 364:148-153. [PMID: 30975883 PMCID: PMC6929210 DOI: 10.1126/science.aav7942] [Citation(s) in RCA: 138] [Impact Index Per Article: 27.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2018] [Accepted: 03/08/2019] [Indexed: 12/23/2022]
Abstract
The parathyroid hormone receptor-1 (PTH1R) is a class B G protein-coupled receptor central to calcium homeostasis and a therapeutic target for osteoporosis and hypoparathyroidism. Here we report the cryo-electron microscopy structure of human PTH1R bound to a long-acting PTH analog and the stimulatory G protein. The bound peptide adopts an extended helix with its amino terminus inserted deeply into the receptor transmembrane domain (TMD), which leads to partial unwinding of the carboxyl terminus of transmembrane helix 6 and induces a sharp kink at the middle of this helix to allow the receptor to couple with G protein. In contrast to a single TMD structure state, the extracellular domain adopts multiple conformations. These results provide insights into the structural basis and dynamics of PTH binding and receptor activation.
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Affiliation(s)
- Li-Hua Zhao
- The CAS Key Laboratory of Receptor Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai 201203, China
| | - Shanshan Ma
- The CAS Key Laboratory of Receptor Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai 201203, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Ieva Sutkeviciute
- Laboratory for GPCR Biology, Department of Pharmacology and Chemical Biology, University of Pittsburgh School of Medicine, University of Pittsburgh, Pittsburgh, PA 15261, USA
| | - Dan-Dan Shen
- Department of Pathology of Sir Run Run Shaw Hospital and Department of Biophysics, Zhejiang University School of Medicine, Hangzhou 310058, China
| | - X Edward Zhou
- Center for Cancer and Cell Biology, Innovation and Integration Program, Van Andel Research Institute, Grand Rapids, MI 49503, USA
| | - Parker W de Waal
- Center for Cancer and Cell Biology, Innovation and Integration Program, Van Andel Research Institute, Grand Rapids, MI 49503, USA
| | - Chen-Yao Li
- The CAS Key Laboratory of Receptor Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai 201203, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Yanyong Kang
- The CAS Key Laboratory of Receptor Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai 201203, China
| | - Lisa J Clark
- Laboratory for GPCR Biology, Department of Pharmacology and Chemical Biology, University of Pittsburgh School of Medicine, University of Pittsburgh, Pittsburgh, PA 15261, USA
- Graduate Program in Molecular Biophysics and Structural Biology, University of Pittsburgh School of Medicine, University of Pittsburgh, Pittsburgh, PA 15261, USA
| | - Frederic G Jean-Alphonse
- Laboratory for GPCR Biology, Department of Pharmacology and Chemical Biology, University of Pittsburgh School of Medicine, University of Pittsburgh, Pittsburgh, PA 15261, USA
| | - Alex D White
- Laboratory for GPCR Biology, Department of Pharmacology and Chemical Biology, University of Pittsburgh School of Medicine, University of Pittsburgh, Pittsburgh, PA 15261, USA
- Graduate Program in Molecular Pharmacology, University of Pittsburgh School of Medicine, University of Pittsburgh, Pittsburgh, PA 15261, USA
| | - Dehua Yang
- The CAS Key Laboratory of Receptor Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai 201203, China
| | - Antao Dai
- The CAS Key Laboratory of Receptor Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai 201203, China
| | - Xiaoqing Cai
- The CAS Key Laboratory of Receptor Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai 201203, China
| | - Jian Chen
- School of Pharmacy, Fudan University, Shanghai 201203, China
| | - Cong Li
- School of Pharmacy, Fudan University, Shanghai 201203, China
| | - Yi Jiang
- The CAS Key Laboratory of Receptor Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai 201203, China
| | - Tomoyuki Watanabe
- Endocrine Unit, Massachusetts General Hospital and Harvard Medical School, Boston, MA 02114, USA
| | - Thomas J Gardella
- Endocrine Unit, Massachusetts General Hospital and Harvard Medical School, Boston, MA 02114, USA
| | - Karsten Melcher
- Center for Cancer and Cell Biology, Innovation and Integration Program, Van Andel Research Institute, Grand Rapids, MI 49503, USA
| | - Ming-Wei Wang
- The CAS Key Laboratory of Receptor Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai 201203, China.
- School of Pharmacy, Fudan University, Shanghai 201203, China
| | - Jean-Pierre Vilardaga
- Laboratory for GPCR Biology, Department of Pharmacology and Chemical Biology, University of Pittsburgh School of Medicine, University of Pittsburgh, Pittsburgh, PA 15261, USA.
| | - H Eric Xu
- The CAS Key Laboratory of Receptor Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai 201203, China.
- Center for Cancer and Cell Biology, Innovation and Integration Program, Van Andel Research Institute, Grand Rapids, MI 49503, USA
| | - Yan Zhang
- Department of Pathology of Sir Run Run Shaw Hospital and Department of Biophysics, Zhejiang University School of Medicine, Hangzhou 310058, China.
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PTH decreases in vitro human cartilage regeneration without affecting hypertrophic differentiation. PLoS One 2019; 14:e0213483. [PMID: 30947269 PMCID: PMC6449021 DOI: 10.1371/journal.pone.0213483] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2019] [Accepted: 03/25/2019] [Indexed: 12/12/2022] Open
Abstract
Regenerated cartilage formed after Autologous Chondrocyte Implantation may be of suboptimal quality due to postulated hypertrophic changes. Parathyroid hormone-related peptide, containing the parathyroid hormone sequence (PTHrP 1–34), enhances cartilage growth during development and inhibits hypertrophic differentiation of mesenchymal stromal cells (MSCs) and growth plate chondrocytes. This study aims to determine the possible anabolic and/or hypertrophic effect of PTH on human articular chondrocytes. Healthy human articular cartilage-derived chondrocytes (n = 6 donors) were cultured on type II collagen-coated transwells with/without 0.1 or 1.0 μM PTH from day 0, 9, or 21 until the end of culture (day 28). Extracellular matrix production, (pre)hypertrophy and PTH signaling were assessed by RT-qPCR and/or immunohistochemistry for collagen type I, II, X, RUNX2, MMP13, PTHR1 and IHH and by determining glycosaminoglycan production and DNA content. The Bern score assessed cartilage quality by histology. Regardless of the concentration and initiation of supplementation, PTH treatment significantly decreased DNA and glycosaminoglycan content and reduced the Bern score compared with controls. Type I collagen deposition was increased, whereas PTHR1 expression and type II collagen deposition were decreased by PTH supplementation. Expression of the (pre)hypertrophic markers MMP13, RUNX2, IHH and type X collagen were not affected by PTH. In conclusion, PTH supplementation to healthy human articular chondrocytes did not affect hypertrophic differentiation, but negatively influenced cartilage quality, the tissues’ extracellular matrix and cell content. Although PTH may be an effective inhibitor of hypertrophic differentiation in MSC-based cartilage repair, care may be warranted in applying accessory PTH treatment due to its effects on articular chondrocytes.
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34
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Laigre E, Goyard D, Tiertant C, Dejeu J, Renaudet O. The study of multivalent carbohydrate-protein interactions by bio-layer interferometry. Org Biomol Chem 2018; 16:8899-8903. [PMID: 30264842 PMCID: PMC6289105 DOI: 10.1039/c8ob01664j] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2018] [Accepted: 08/17/2018] [Indexed: 12/18/2022]
Abstract
The study of complex multivalent carbohydrate-protein interactions remains highly complicated and sometimes rendered impossible due to aggregation problems. In this study, we demonstrate that bio-layer interferometry is an excellent complementary method to standard techniques such as SPR and ITC. Using tetra- and hexadecavalent GalNAc glycoconjugates and Helix pomatia agglutinin (HPA) as a model lectin, we were able to measure reliable kinetic and thermodynamic parameters of multivalent interactions going from the micro to the nanomolar range.
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Affiliation(s)
- Eugénie Laigre
- Univ. Grenoble Alpes
, CNRS
, DCM UMR 5250
,
F-38000 Grenoble
, France
.
;
| | - David Goyard
- Univ. Grenoble Alpes
, CNRS
, DCM UMR 5250
,
F-38000 Grenoble
, France
.
;
| | - Claire Tiertant
- Univ. Grenoble Alpes
, CNRS
, DCM UMR 5250
,
F-38000 Grenoble
, France
.
;
| | - Jérôme Dejeu
- Univ. Grenoble Alpes
, CNRS
, DCM UMR 5250
,
F-38000 Grenoble
, France
.
;
| | - Olivier Renaudet
- Univ. Grenoble Alpes
, CNRS
, DCM UMR 5250
,
F-38000 Grenoble
, France
.
;
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35
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Culhane KJ, Belina ME, Sims JN, Cai Y, Liu Y, Wang PSP, Yan ECY. Parathyroid Hormone Senses Extracellular Calcium To Modulate Endocrine Signaling upon Binding to the Family B GPCR Parathyroid Hormone 1 Receptor. ACS Chem Biol 2018; 13:2347-2358. [PMID: 29952553 PMCID: PMC10640708 DOI: 10.1021/acschembio.8b00568] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Parathyroid hormone (PTH) binds to a family B G protein coupled receptor, parathyroid hormone 1 receptor (PTH1R). One of its functions is to regulate Ca2+ homeostasis in bone remodeling, during which Ca2+ can reach up to 40 mM. A truncated version of PTH, PTH(1-34), can fully activate PTH1R and has been used for osteoporosis treatments. Here, we used fluorescence anisotropy to examine the binding of PTH(1-34) to PTH1R purified in nanodiscs (PTH1R-ND) and found that the affinity increases 5-fold in the presence of 15 mM Ca2+. However, PTHrP(1-36), another truncated endogenous agonist for PTH1R, does not show this Ca2+ effect. Mutations of Glu19 and Glu22 in PTH(1-34) that are not conserved in PTHrP(1-36) largely abolished the Ca2+ effect. The results support that PTH(1-34) not only activates PTH1R but also uniquely senses Ca2+. This dual function of a peptide hormone is a novel observation that couples changes in extracellular environment with endocrine signaling. Understanding this can potentially reveal the complex role of PTH signaling in bone remodeling and improve the PTH(1-34) treatment for osteoporosis.
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Affiliation(s)
- Kelly J. Culhane
- Department of Molecular Biophysics and Biochemistry, Yale University, 266 Whitney Ave, New Haven, Connecticut 06520, USA
| | - Morgan E. Belina
- Department of Chemistry, Yale University, 225 Prospect Street, New Haven, Connecticut 06520, USA
| | - Jeremiah N. Sims
- Department of Chemistry, Yale University, 225 Prospect Street, New Haven, Connecticut 06520, USA
| | - Yingying Cai
- Department of Chemistry, Yale University, 225 Prospect Street, New Haven, Connecticut 06520, USA
| | - Yuting Liu
- Department of Chemistry, Yale University, 225 Prospect Street, New Haven, Connecticut 06520, USA
| | - Pam S. P. Wang
- Department of Chemistry, Yale University, 225 Prospect Street, New Haven, Connecticut 06520, USA
| | - Elsa C. Y. Yan
- Department of Chemistry, Yale University, 225 Prospect Street, New Haven, Connecticut 06520, USA
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36
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Weaver SR, Hernandez LL. Could use of Selective Serotonin Reuptake Inhibitors During Lactation Cause Persistent Effects on Maternal Bone? J Mammary Gland Biol Neoplasia 2018; 23:5-25. [PMID: 29603039 DOI: 10.1007/s10911-018-9390-6] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/14/2017] [Accepted: 03/13/2018] [Indexed: 02/07/2023] Open
Abstract
The lactating mammary gland elegantly coordinates maternal homeostasis to provide calcium for milk. During lactation, the monoamine serotonin regulates the synthesis and release of various mammary gland-derived factors, such as parathyroid hormone-related protein (PTHrP), to stimulate bone resorption. Recent evidence suggests that bone mineral lost during prolonged lactation is not fully recovered following weaning, possibly putting women at increased risk of fracture or osteoporosis. Selective Serotonin Reuptake Inhibitor (SSRI) antidepressants have also been associated with reduced bone mineral density and increased fracture risk. Therefore, SSRI exposure while breastfeeding may exacerbate lactational bone loss, compromising long-term bone health. Through an examination of serotonin and calcium homeostasis during lactation, lactational bone turnover and post-weaning recovery of bone mineral, and the effect of peripartum depression and SSRI on the mammary gland and bone, this review will discuss the hypothesis that peripartum SSRI exposure causes persistent reductions in bone mineral density through mammary-derived PTHrP signaling with bone.
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Affiliation(s)
- Samantha R Weaver
- Endocrine and Reproductive Physiology Program, University of Wisconsin-Madison, Madison, WI, USA
| | - Laura L Hernandez
- Department of Dairy Science, University of Wisconsin-Madison, Madison, WI, USA.
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37
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Karageorgos V, Venihaki M, Sakellaris S, Pardalos M, Kontakis G, Matsoukas MT, Gravanis A, Margioris A, Liapakis G. Current understanding of the structure and function of family B GPCRs to design novel drugs. Hormones (Athens) 2018; 17:45-59. [PMID: 29858864 DOI: 10.1007/s42000-018-0009-5] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/03/2017] [Accepted: 01/25/2018] [Indexed: 01/10/2023]
Abstract
Family B of G-protein-coupled receptors (GPCRs) and their ligands play a central role in a number of homeostatic mechanisms in the endocrine, gastrointestinal, skeletal, immune, cardiovascular and central nervous systems. Alterations in family B GPCR-regulated homeostatic mechanisms may cause a variety of potentially life-threatening conditions, signifying the necessity to develop novel ligands targeting these receptors. Obtaining structural and functional information on family B GPCRs will accelerate the development of novel drugs to target these receptors. Family B GPCRs are proteins that span the plasma membrane seven times, thus forming seven transmembrane domains (TM1-TM7) which are connected to each other by three extracellular (EL) and three intracellular (IL) loops. In addition, these receptors have a long extracellular N-domain and an intracellular C-tail. The upper parts of the TMs and ELs form the J-domain of receptors. The C-terminal region of peptides first binds to the N-domain of receptors. This 'first-step' interaction orients the N-terminal region of peptides towards the J-domain of receptors, thus resulting in a 'second-step' of ligand-receptor interaction that activates the receptor. Activation-associated structural changes of receptors are transmitted through TMs to their intracellular regions and are responsible for their interaction with the G proteins and activation of the latter, thus resulting in a biological effect. This review summarizes the current information regarding the structure and function of family B GPCRs and their physiological and pathophysiological roles.
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Affiliation(s)
- Vlasios Karageorgos
- Department of Pharmacology, School of Medicine, University of Crete, Voutes, 71003, Heraklion, Crete, Greece
| | - Maria Venihaki
- Department of Clinical Chemistry, School of Medicine, University of Crete, Heraklion, Crete, Greece
| | - Stelios Sakellaris
- Department of Pharmacology, School of Medicine, University of Crete, Voutes, 71003, Heraklion, Crete, Greece
| | - Michail Pardalos
- Department of Pharmacology, School of Medicine, University of Crete, Voutes, 71003, Heraklion, Crete, Greece
| | - George Kontakis
- Department of Orthopedics, University Hospital of Heraklion, Crete, Greece
| | | | - Achille Gravanis
- Department of Pharmacology, School of Medicine, University of Crete, Voutes, 71003, Heraklion, Crete, Greece
| | - Andreas Margioris
- Department of Clinical Chemistry, School of Medicine, University of Crete, Heraklion, Crete, Greece
| | - George Liapakis
- Department of Pharmacology, School of Medicine, University of Crete, Voutes, 71003, Heraklion, Crete, Greece.
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38
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Lemos A, Melo R, Preto AJ, Almeida JG, Moreira IS, Cordeiro MNDS. In Silico Studies Targeting G-protein Coupled Receptors for Drug Research Against Parkinson's Disease. Curr Neuropharmacol 2018; 16:786-848. [PMID: 29521236 PMCID: PMC6080095 DOI: 10.2174/1570159x16666180308161642] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2017] [Revised: 02/16/2018] [Accepted: 02/02/2018] [Indexed: 11/22/2022] Open
Abstract
Parkinson's Disease (PD) is a long-term neurodegenerative brain disorder that mainly affects the motor system. The causes are still unknown, and even though currently there is no cure, several therapeutic options are available to manage its symptoms. The development of novel antiparkinsonian agents and an understanding of their proper and optimal use are, indeed, highly demanding. For the last decades, L-3,4-DihydrOxyPhenylAlanine or levodopa (L-DOPA) has been the gold-standard therapy for the symptomatic treatment of motor dysfunctions associated to PD. However, the development of dyskinesias and motor fluctuations (wearing-off and on-off phenomena) associated with long-term L-DOPA replacement therapy have limited its antiparkinsonian efficacy. The investigation for non-dopaminergic therapies has been largely explored as an attempt to counteract the motor side effects associated with dopamine replacement therapy. Being one of the largest cell membrane protein families, G-Protein-Coupled Receptors (GPCRs) have become a relevant target for drug discovery focused on a wide range of therapeutic areas, including Central Nervous System (CNS) diseases. The modulation of specific GPCRs potentially implicated in PD, excluding dopamine receptors, may provide promising non-dopaminergic therapeutic alternatives for symptomatic treatment of PD. In this review, we focused on the impact of specific GPCR subclasses, including dopamine receptors, adenosine receptors, muscarinic acetylcholine receptors, metabotropic glutamate receptors, and 5-hydroxytryptamine receptors, on the pathophysiology of PD and the importance of structure- and ligand-based in silico approaches for the development of small molecules to target these receptors.
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Affiliation(s)
- Agostinho Lemos
- LAQV/REQUIMTE, Department of Chemistry and Biochemistry, Faculty of Sciences, University of Porto, Rua do Campo Alegre s/n, 4169-007Porto, Portugal
- GIGA Cyclotron Research Centre In Vivo Imaging, University of Liège, 4000Liège, Belgium
| | - Rita Melo
- CNC - Center for Neuroscience and Cell Biology, Faculty of Medicine, University of Coimbra, Rua Larga, 3004-517Coimbra, Portugal
- Centro de Ciências e Tecnologias Nucleares, Instituto Superior Técnico, Universidade de Lisboa, Estrada Nacional 10 (ao km 139,7), 2695-066 Bobadela LRS, Portugal
| | - Antonio Jose Preto
- CNC - Center for Neuroscience and Cell Biology, Faculty of Medicine, University of Coimbra, Rua Larga, 3004-517Coimbra, Portugal
| | - Jose Guilherme Almeida
- CNC - Center for Neuroscience and Cell Biology, Faculty of Medicine, University of Coimbra, Rua Larga, 3004-517Coimbra, Portugal
| | - Irina Sousa Moreira
- CNC - Center for Neuroscience and Cell Biology, Faculty of Medicine, University of Coimbra, Rua Larga, 3004-517Coimbra, Portugal
- Bijvoet Center for Biomolecular Research, Faculty of Science - Chemistry, Utrecht University, Utrecht, 3584CH, The Netherlands
| | - Maria Natalia Dias Soeiro Cordeiro
- LAQV/REQUIMTE, Department of Chemistry and Biochemistry, Faculty of Sciences, University of Porto, Rua do Campo Alegre s/n, 4169-007Porto, Portugal
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Cheloha RW, Chen B, Kumar NN, Watanabe T, Thorne RG, Li L, Gardella TJ, Gellman SH. Development of Potent, Protease-Resistant Agonists of the Parathyroid Hormone Receptor with Broad β Residue Distribution. J Med Chem 2017; 60:8816-8833. [PMID: 29064243 DOI: 10.1021/acs.jmedchem.7b00876] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
The parathyroid hormone receptor 1 (PTHR1) is a member of the B-family of GPCRs; these receptors are activated by long polypeptide hormones and constitute targets of drug development efforts. Parathyroid hormone (PTH, 84 residues) and PTH-related protein (PTHrP, 141 residues) are natural agonists of PTHR1, and an N-terminal fragment of PTH, PTH(1-34), is used clinically to treat osteoporosis. Conventional peptides in the 20-40-mer length range are rapidly degraded by proteases, which may limit their biomedical utility. We have used the PTHR1-ligand system to explore the impact of broadly distributed replacement of α-amino acid residues with β-amino acid residues on susceptibility to proteolysis and agonist activity. This effort led us to identify new PTHR1 agonists that contain α → β replacements throughout their sequences, manifest potent agonist activity in cellular assays, and display remarkable resistance to proteolysis, in cases remaining active after extended exposure to simulated gastric fluid. The strategy we have employed suggests a path toward identifying protease-resistant agonists of other B-family GPCRs.
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Affiliation(s)
- Ross W Cheloha
- Department of Chemistry, University of Wisconsin-Madison , 1101 University Avenue, Madison, Wisconsin 53706, United States
| | - Bingming Chen
- School of Pharmacy, University of Wisconsin-Madison , 777 Highland Avenue, Madison, Wisconsin 53705, United States
| | - Niyanta N Kumar
- School of Pharmacy, University of Wisconsin-Madison , 777 Highland Avenue, Madison, Wisconsin 53705, United States
| | - Tomoyuki Watanabe
- Endocrine Unit, Massachusetts General Hospital and Harvard Medical School , Boston, Massachusetts 02114, United States
| | - Robert G Thorne
- School of Pharmacy, University of Wisconsin-Madison , 777 Highland Avenue, Madison, Wisconsin 53705, United States.,Clinical Neuroengineering Training Program, University of Wisconsin-Madison Biomedical Engineering , Engineering Centers Building, Room 2120, 1550 Engineering Drive, Madison Wisconsin 53706, United States.,Neuroscience Training Program & Center for Neuroscience, Wisconsin Institutes for Medical Research II , Rooms 9531 and 9533, 1111 Highland Avenue, Madison, Wisconsin 53705, United States.,Cellular and Molecular Pathology Graduate Training Program, UW Department of Pathology and Laboratory Medicine, University of Wisconsin-Madison , 1685 Highland Avenue, Madison, Wisconsin 53705, United States
| | - Lingjun Li
- Department of Chemistry, University of Wisconsin-Madison , 1101 University Avenue, Madison, Wisconsin 53706, United States.,School of Pharmacy, University of Wisconsin-Madison , 777 Highland Avenue, Madison, Wisconsin 53705, United States
| | - Thomas J Gardella
- Endocrine Unit, Massachusetts General Hospital and Harvard Medical School , Boston, Massachusetts 02114, United States
| | - Samuel H Gellman
- Department of Chemistry, University of Wisconsin-Madison , 1101 University Avenue, Madison, Wisconsin 53706, United States
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40
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Charest-Morin X, Poubelle PE, Marceau F. Production and evaluation of parathyroid hormone receptor 1 ligands with intrinsic or assembled peroxidase domains. Sci Rep 2017; 7:13099. [PMID: 29026164 PMCID: PMC5638942 DOI: 10.1038/s41598-017-13548-0] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2017] [Accepted: 09/26/2017] [Indexed: 12/28/2022] Open
Abstract
Parathyroid hormone (PTH) can be C-terminally extended without significant affinity loss for the PTH1 receptor (PTHR1). We developed fusion protein ligands with enzymatic activity to probe PTHR1s at the cell surface. Two fusion proteins were generated by linking PTH to the N-terminus of either horseradish peroxidase (PTH-HRP) or the genetically modified soybean peroxidase APEX2 (PTH-APEX2). Alternatively, myc-tagged PTH (PTH-myc) was combined with antibodies, some of which HRP-conjugated, in the extracellular fluid. The three PTH-fusion proteins were produced as conditioned mediums (CM) by transfected producer HEK 293a cells. Binding of receptor-bound enzymatic ligands was revealed using widely available substrate/co-substrate systems. The stimulation of recipient HEK 293a expressing PTHR1s with the PTH-myc/antibodies combination or with PTH-APEX2 supported the histochemical or luminescent detection of recombinant PTHR1s (TrueBlueTM or luminol-based reagent). The PTH-HRP construction was the most sensitive and supported all tested peroxidase co-substrates (TrueBlueTM, tetramethylbenzidine (TMB), luminol, biotin-phenol with streptavidin-Qdots); the 3 latter schemes identified endogenous PTHR1 in the osteoblastic HOS cell line. The specificity of the fusion protein binding to PTHR1 was determined by its competition with an excess of PTH1–34. Bifunctional ligands possessing enzymatic activity detect intact receptors with various possible applications, including the screening of drugs that compete for receptor binding.
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Affiliation(s)
- Xavier Charest-Morin
- Division of Infectious Disease and Immunity, CHU de Québec-Université Laval, Quebec City, QC, G1V 4G2, Canada
| | - Patrice E Poubelle
- Division of Infectious Disease and Immunity, CHU de Québec-Université Laval, Quebec City, QC, G1V 4G2, Canada
| | - François Marceau
- Division of Infectious Disease and Immunity, CHU de Québec-Université Laval, Quebec City, QC, G1V 4G2, Canada.
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41
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Kamalakar A, Washam CL, Akel NS, Allen BJ, Williams DK, Swain FL, Leitzel K, Lipton A, Gaddy D, Suva LJ. PTHrP(12-48) Modulates the Bone Marrow Microenvironment and Suppresses Human Osteoclast Differentiation and Lifespan. J Bone Miner Res 2017; 32:1421-1431. [PMID: 28370412 PMCID: PMC5518789 DOI: 10.1002/jbmr.3142] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/23/2016] [Revised: 03/09/2017] [Accepted: 03/24/2017] [Indexed: 01/08/2023]
Abstract
Bone is a common site for metastasis in breast cancer patients and is associated with a series of complications that significantly compromise patient survival, partially due to the advanced stage of disease at the time of detection. Currently, no clinically-approved biomarkers can identify or predict the development of bone metastasis. We recently identified a unique peptide fragment of parathyroid hormone-related protein (PTHrP), PTHrP(12-48), as a validated serum biomarker in breast cancer patients that correlates with and predicts the presence of bone metastases. In this study, the biological activity and mode of action of PTHrP(12-48) was investigated. Sequence-based and structure-based bioinformatics techniques predicted that the PTHrP(12-48) fragment formed an alpha helical core followed by an unstructured region after residue 40 or 42. Thereafter, detailed structure alignment and molecular docking simulations predicted a lack of interaction between PTHrP(12-48) and the cognate PTH1 receptor (PTHR1). The in silico prediction was confirmed by the lack of PTHrP(12-48)-stimulated cAMP accumulation in PTHR1-expressing human SaOS2 cells. Using a specific human PTHrP(12-48) antibody that we developed, PTHrP(12-48) was immunolocalized in primary and bone metastatic human breast cancer cells, as well as within human osteoclasts (OCLs) in bone metastasis biopsies, with little or no localization in other resident bone or bone marrow cells. In vitro, PTHrP(12-48) was internalized into cultured primary human OCLs and their precursors within 60 min. Interestingly, PTHrP(12-48) treatment dose-dependently suppressed osteoclastogenesis, via the induction of apoptosis in both OCL precursors as well as in mature OCLs, as measured by the activation of cleaved caspase 3. Collectively, these data suggest that PTHrP(12-48) is a bioactive breast cancer-derived peptide that locally regulates the differentiation of hematopoietic cells and the activity of osteoclasts within the tumor-bone marrow microenvironment, perhaps to facilitate tumor control of bone. © 2017 American Society for Bone and Mineral Research.
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Affiliation(s)
- Archana Kamalakar
- Department of Orthopaedic Surgery, Center for Orthopaedic Research, University of Arkansas for Medical Sciences (UAMS), Little Rock, AR, USA
| | - Charity L Washam
- Department of Orthopaedic Surgery, Center for Orthopaedic Research, University of Arkansas for Medical Sciences (UAMS), Little Rock, AR, USA
| | - Nisreen S Akel
- Department of Orthopaedic Surgery, Center for Orthopaedic Research, University of Arkansas for Medical Sciences (UAMS), Little Rock, AR, USA
| | - Bethany J Allen
- Department of Orthopaedic Surgery, Center for Orthopaedic Research, University of Arkansas for Medical Sciences (UAMS), Little Rock, AR, USA
| | - Diarra K Williams
- Department of Orthopaedic Surgery, Center for Orthopaedic Research, University of Arkansas for Medical Sciences (UAMS), Little Rock, AR, USA.,Department of Veterinary Physiology and Pharmacology, College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, TX, USA
| | - Frances L Swain
- Department of Orthopaedic Surgery, Center for Orthopaedic Research, University of Arkansas for Medical Sciences (UAMS), Little Rock, AR, USA
| | - Kim Leitzel
- Department of Medicine, Penn State University, Milton S. Hershey Medical Center, Hershey, PA, USA
| | - Allan Lipton
- Department of Medicine, Penn State University, Milton S. Hershey Medical Center, Hershey, PA, USA
| | - Dana Gaddy
- Department of Orthopaedic Surgery, Center for Orthopaedic Research, University of Arkansas for Medical Sciences (UAMS), Little Rock, AR, USA.,Veterinary Integrative Biosciences, College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, TX, USA
| | - Larry J Suva
- Department of Orthopaedic Surgery, Center for Orthopaedic Research, University of Arkansas for Medical Sciences (UAMS), Little Rock, AR, USA.,Department of Veterinary Physiology and Pharmacology, College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, TX, USA
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42
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Lee SM, Booe JM, Gingell JJ, Sjoelund V, Hay DL, Pioszak AA. N-Glycosylation of Asparagine 130 in the Extracellular Domain of the Human Calcitonin Receptor Significantly Increases Peptide Hormone Affinity. Biochemistry 2017; 56:3380-3393. [PMID: 28614667 DOI: 10.1021/acs.biochem.7b00256] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The calcitonin receptor (CTR) is a class B G protein-coupled receptor that is activated by the peptide hormones calcitonin and amylin. Calcitonin regulates bone remodeling through CTR, whereas amylin regulates blood glucose and food intake by activating CTR in complex with receptor activity-modifying proteins (RAMPs). These receptors are targeted clinically for the treatment of osteoporosis and diabetes. Here, we define the role of CTR N-glycosylation in hormone binding using purified calcitonin and amylin receptor extracellular domain (ECD) glycoforms and fluorescence polarization/anisotropy and isothermal titration calorimetry peptide-binding assays. N-Glycan-free CTR ECD produced in Escherichia coli exhibited ∼10-fold lower peptide affinity than CTR ECD produced in HEK293T cells, which yield complex N-glycans, or in HEK293S GnTI- cells, which yield core N-glycans (Man5GlcNAc2). PNGase F-catalyzed removal of N-glycans at N73, N125, and N130 in the CTR ECD decreased peptide affinity ∼10-fold, whereas Endo H-catalyzed trimming of the N-glycans to single GlcNAc residues had no effect on peptide binding. Similar results were observed for an amylin receptor RAMP2-CTR ECD complex. Characterization of peptide-binding affinities of purified N → Q CTR ECD glycan site mutants combined with PNGase F and Endo H treatment strategies and mass spectrometry to define the glycan species indicated that a single GlcNAc residue at CTR N130 was responsible for the peptide affinity enhancement. Molecular modeling suggested that this GlcNAc functions through an allosteric mechanism rather than by directly contacting the peptide. These results reveal an important role for N-linked glycosylation in the peptide hormone binding of a clinically relevant class B GPCR.
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Affiliation(s)
- Sang-Min Lee
- Department of Biochemistry and Molecular Biology, University of Oklahoma Health Sciences Center , 975 NE 10th Street BRC 462B, Oklahoma City, Oklahoma 73104, United States
| | - Jason M Booe
- Department of Biochemistry and Molecular Biology, University of Oklahoma Health Sciences Center , 975 NE 10th Street BRC 462B, Oklahoma City, Oklahoma 73104, United States
| | | | - Virginie Sjoelund
- Proteomics Division of the Laboratory for Molecular Biology and Cytometry Research, University of Oklahoma Health Sciences Center , 975 NE 10th Street, Oklahoma City, Oklahoma 73104, United States
| | | | - Augen A Pioszak
- Department of Biochemistry and Molecular Biology, University of Oklahoma Health Sciences Center , 975 NE 10th Street BRC 462B, Oklahoma City, Oklahoma 73104, United States
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43
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Chew CK, Clarke BL. Abaloparatide: Recombinant human PTHrP (1-34) anabolic therapy for osteoporosis. Maturitas 2016; 97:53-60. [PMID: 28159062 DOI: 10.1016/j.maturitas.2016.12.003] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2016] [Revised: 11/30/2016] [Accepted: 12/07/2016] [Indexed: 01/15/2023]
Abstract
The treatment of osteoporosis is generally either by inhibition of bone resorption with antiresorptive agents or by stimulation of bone formation with anabolic agents. Currently, teriparatide (recombinant human parathyroid hormone 1-34 [rhPTH (1-34)]) is the only available approved anabolic agent in the U.S. Other anabolic agents are under investigation however. Abaloparatide is recombinant human parathyroid hormone-related peptide 1-34. This agent is an anabolic agent that appears more potent than teriparatide, and it may have more rapid onset of fracture reduction than teriparatide. It is currently undergoing FDA review, with approval expected in 2017.
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Affiliation(s)
- Chee Kian Chew
- Mayo Clinic E18-A, 200 1st Street SW, Rochester, MN, 55905 USA
| | - Bart L Clarke
- Mayo Clinic E18-A, 200 1st Street SW, Rochester, MN, 55905 USA.
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44
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An intrinsic agonist mechanism for activation of glucagon-like peptide-1 receptor by its extracellular domain. Cell Discov 2016; 2:16042. [PMID: 27917297 PMCID: PMC5118412 DOI: 10.1038/celldisc.2016.42] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2016] [Accepted: 10/18/2016] [Indexed: 12/25/2022] Open
Abstract
The glucagon-like peptide-1 receptor is a class B G protein coupled receptor (GPCR) that plays key roles in glucose metabolism and is a major therapeutic target for diabetes. The classic two-domain model for class B GPCR activation proposes that the apo-state receptor is auto-inhibited by its extracellular domain, which physically interacts with the transmembrane domain. The binding of the C-terminus of the peptide hormone to the extracellular domain allows the N-terminus of the hormone to insert into the transmembrane domain to induce receptor activation. In contrast to this model, here we demonstrate that glucagon-like peptide-1 receptor can be activated by N-terminally truncated glucagon-like peptide-1 or exendin-4 when fused to the receptor, raising the question regarding the role of N-terminal residues of peptide hormone in glucagon-like peptide-1 receptor activation. Mutations of cysteine 347 to lysine or arginine in intracellular loop 3 transform the receptor into a G protein-biased receptor and allow it to be activated by a nonspecific five-residue linker that is completely devoid of exendin-4 or glucagon-like peptide-1 sequence but still requires the presence of an intact extracellular domain. Moreover, the extracellular domain can activate the receptor in trans in the presence of an intact peptide hormone, and specific mutations in three extracellular loops abolished this extracellular domain trans-activation. Together, our data reveal a dominant role of the extracellular domain in glucagon-like peptide-1 receptor activation and support an intrinsic agonist model of the extracellular domain, in which peptide binding switches the receptor from the auto-inhibited state to the auto-activated state by releasing the intrinsic agonist activity of the extracellular domain.
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45
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Bahar H, Gallacher K, Downall J, Nelson CA, Shomali M, Hattersley G. Six Weeks of Daily Abaloparatide Treatment Increased Vertebral and Femoral Bone Mineral Density, Microarchitecture and Strength in Ovariectomized Osteopenic Rats. Calcif Tissue Int 2016; 99:489-499. [PMID: 27395059 PMCID: PMC5055567 DOI: 10.1007/s00223-016-0171-1] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/25/2016] [Accepted: 06/25/2016] [Indexed: 01/22/2023]
Abstract
Abaloparatide is a novel, potent and selective activator of parathyroid hormone receptor 1 (PTHR1) under clinical development for the treatment of osteoporosis. We assessed the effect of 6 weeks of abaloparatide on bone mass, microarchitecture, quality and strength in ovariectomized (OVX) rats. After 8 weeks of post-surgical bone depletion (baseline), OVX rats (n = 20-21/group) received daily subcutaneous vehicle (OVX-Veh) or abaloparatide at 5 or 20 µg/kg. Sham-operated control rats (n = 24) received vehicle. Areal bone mineral density (aBMD) of the lumbar spine (L4), total femur and femur diaphysis was measured at baseline and after 6 weeks of treatment. Femur and vertebral bone architecture and mechanical properties were assessed at the end of the treatment phase. At baseline, OVX-Veh rats exhibited significantly lower aBMD relative to Sham controls. Treatment of OVX rats with abaloparatide at 5 or 20 µg/kg/day increased aBMD dose-dependently in the lumbar spine, total femur and femur diaphysis to levels exceeding OVX-Veh or Sham controls. The abaloparatide 5 and 20 µg/kg groups had improved trabecular microarchitecture relative to OVX vehicle, with trabecular BV/TV exceeding OVX-Veh control values by 57 and 78 % (respectively) at the lumbar spine, and by 145 and 270 % at the distal femur. Femur diaphyseal cortical volume and thickness were significantly greater in the abaloparatide 20 µg/kg group relative to OVX vehicle or Sham controls. Bone strength parameters of the femur diaphysis, femur neck and L4 vertebra were significantly improved in the OVX-ABL groups relative to OVX-Veh controls. Bone mass-strength relationships and estimated intrinsic strength properties suggested maintained or improved bone quality with abaloparatide. These data demonstrate skeletal restoration via abaloparatide treatment of osteopenic OVX rats, in association with improved trabecular microarchitecture, cortical geometry and bone strength at sites that have clinical relevance in patients with osteoporosis.
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Affiliation(s)
- Hila Bahar
- Radius Health, 950 Winter Street, Waltham, MA, 02451, USA
| | - Kyla Gallacher
- Radius Health, 950 Winter Street, Waltham, MA, 02451, USA
| | - Julie Downall
- Radius Health, 950 Winter Street, Waltham, MA, 02451, USA
| | - Carol A Nelson
- Radius Health, 950 Winter Street, Waltham, MA, 02451, USA
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46
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Martin TJ. Parathyroid Hormone-Related Protein, Its Regulation of Cartilage and Bone Development, and Role in Treating Bone Diseases. Physiol Rev 2016; 96:831-71. [DOI: 10.1152/physrev.00031.2015] [Citation(s) in RCA: 99] [Impact Index Per Article: 12.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Although parathyroid hormone-related protein (PTHrP) was discovered as a cancer-derived hormone, it has been revealed as an important paracrine/autocrine regulator in many tissues, where its effects are context dependent. Thus its location and action in the vasculature explained decades-long observations that injection of PTH into animals rapidly lowered blood pressure by producing vasodilatation. Its roles have been specified in development and maturity in cartilage and bone as a crucial regulator of endochondral bone formation and bone remodeling, respectively. Although it shares actions with parathyroid hormone (PTH) through the use of their common receptor, PTHR1, PTHrP has other actions mediated by regions within the molecule beyond the amino-terminal sequence that resembles PTH, including the ability to promote placental transfer of calcium from mother to fetus. A striking feature of the physiology of PTHrP is that it possesses structural features that equip it to be transported in and out of the nucleus, and makes use of a specific nuclear import mechanism to do so. Evidence from mouse genetic experiments shows that PTHrP generated locally in bone is essential for normal bone remodeling. Whereas the main physiological function of PTH is the hormonal regulation of calcium metabolism, locally generated PTHrP is the important physiological mediator of bone remodeling postnatally. Thus the use of intermittent injection of PTH as an anabolic therapy for bone appears to be a pharmacological application of the physiological function of PTHrP. There is much current interest in the possibility of developing PTHrP analogs that might enhance the therapeutic anabolic effects.
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Affiliation(s)
- T. John Martin
- St Vincent's Institute of Medical Research, Department of Medicine, University of Melbourne, St Vincent's Hospital, Melbourne, Australia
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47
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J Gingell J, Simms J, Barwell J, Poyner DR, Watkins HA, Pioszak AA, Sexton PM, Hay DL. An allosteric role for receptor activity-modifying proteins in defining GPCR pharmacology. Cell Discov 2016; 2:16012. [PMID: 27462459 PMCID: PMC4869360 DOI: 10.1038/celldisc.2016.12] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2016] [Accepted: 02/24/2016] [Indexed: 12/15/2022] Open
Abstract
G protein-coupled receptors are allosteric proteins that control transmission of external signals to regulate cellular response. Although agonist binding promotes canonical G protein signalling transmitted through conformational changes, G protein-coupled receptors also interact with other proteins. These include other G protein-coupled receptors, other receptors and channels, regulatory proteins and receptor-modifying proteins, notably receptor activity-modifying proteins (RAMPs). RAMPs have at least 11 G protein-coupled receptor partners, including many class B G protein-coupled receptors. Prototypic is the calcitonin receptor, with altered ligand specificity when co-expressed with RAMPs. To gain molecular insight into the consequences of this protein–protein interaction, we combined molecular modelling with mutagenesis of the calcitonin receptor extracellular domain, assessed in ligand binding and functional assays. Although some calcitonin receptor residues are universally important for peptide interactions (calcitonin, amylin and calcitonin gene-related peptide) in calcitonin receptor alone or with receptor activity-modifying protein, others have RAMP-dependent effects, whereby mutations decreased amylin/calcitonin gene-related peptide potency substantially only when RAMP was present. Remarkably, the key residues were completely conserved between calcitonin receptor and AMY receptors, and between subtypes of AMY receptor that have different ligand preferences. Mutations at the interface between calcitonin receptor and RAMP affected ligand pharmacology in a RAMP-dependent manner, suggesting that RAMP may allosterically influence the calcitonin receptor conformation. Supporting this, molecular dynamics simulations suggested that the calcitonin receptor extracellular N-terminal domain is more flexible in the presence of receptor activity-modifying protein 1. Thus, RAMPs may act in an allosteric manner to generate a spectrum of unique calcitonin receptor conformational states, explaining the pharmacological preferences of calcitonin receptor-RAMP complexes. This provides novel insight into our understanding of G protein-coupled receptor-protein interaction that is likely broadly applicable for this receptor class.
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Affiliation(s)
- Joseph J Gingell
- School of Biological Sciences, University of Auckland, Auckland, New Zealand; Maurice Wilkins Centre for Molecular Biodiscovery, University of Auckland, Auckland, New Zealand
| | - John Simms
- School of Life and Health Sciences, Aston University , Birmingham, UK
| | - James Barwell
- School of Life and Health Sciences, Aston University , Birmingham, UK
| | - David R Poyner
- School of Life and Health Sciences, Aston University , Birmingham, UK
| | - Harriet A Watkins
- School of Biological Sciences, University of Auckland, Auckland, New Zealand; Maurice Wilkins Centre for Molecular Biodiscovery, University of Auckland, Auckland, New Zealand
| | - Augen A Pioszak
- Department of Biochemistry and Molecular Biology, University of Oklahoma Health Sciences Center , Oklahoma City, OK, USA
| | - Patrick M Sexton
- Drug Discovery Biology and Department of Pharmacology, Monash Institute of Pharmaceutical Sciences, Monash University , Parkville, VIC, Australia
| | - Debbie L Hay
- School of Biological Sciences, University of Auckland, Auckland, New Zealand; Maurice Wilkins Centre for Molecular Biodiscovery, University of Auckland, Auckland, New Zealand
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48
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Gennari L, Rotatori S, Bianciardi S, Nuti R, Merlotti D. Treatment needs and current options for postmenopausal osteoporosis. Expert Opin Pharmacother 2016; 17:1141-52. [DOI: 10.1080/14656566.2016.1176147] [Citation(s) in RCA: 50] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Affiliation(s)
- Luigi Gennari
- Department of Medicine, Surgery and Neurosciences, University of Siena, Siena, Italy
| | - Stefano Rotatori
- Department of Medicine, Surgery and Neurosciences, University of Siena, Siena, Italy
| | - Simone Bianciardi
- Department of Medicine, Surgery and Neurosciences, University of Siena, Siena, Italy
| | - Ranuccio Nuti
- Department of Medicine, Surgery and Neurosciences, University of Siena, Siena, Italy
| | - Daniela Merlotti
- Department of Medicine, Surgery and Neurosciences, University of Siena, Siena, Italy
- Division of Genetics and Cell Biology, Age Related Diseases, San Raffaele Scientific Institute, Milano, Italy
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49
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Johansson E, Hansen JL, Hansen AMK, Shaw AC, Becker P, Schäffer L, Reedtz-Runge S. Type II Turn of Receptor-bound Salmon Calcitonin Revealed by X-ray Crystallography. J Biol Chem 2016; 291:13689-98. [PMID: 27189946 DOI: 10.1074/jbc.m116.726034] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2016] [Indexed: 12/20/2022] Open
Abstract
Calcitonin is a peptide hormone consisting of 32 amino acid residues and the calcitonin receptor is a Class B G protein-coupled receptor (GPCR). The crystal structure of the human calcitonin receptor ectodomain (CTR ECD) in complex with a truncated analogue of salmon calcitonin ([BrPhe(22)]sCT(8-32)) has been determined to 2.1-Å resolution. Parallel analysis of a series of peptide ligands showed that the rank order of binding of the CTR ECD is identical to the rank order of binding of the full-length CTR, confirming the structural integrity and relevance of the isolated CTR ECD. The structure of the CTR ECD is similar to other Class B GPCRs and the ligand binding site is similar to the binding site of the homologous receptors for the calcitonin gene-related peptide (CGRP) and adrenomedulin (AM) recently published (Booe, J. M., Walker, C. S., Barwell, J., Kuteyi, G., Simms, J., Jamaluddin, M. A., Warner, M. L., Bill, R. M., Harris, P. W., Brimble, M. A., Poyner, D. R., Hay, D. L., and Pioszak, A. A. (2015) Mol. Cell 58, 1040-1052). Interestingly the receptor-bound structure of the ligand [BrPhe(22)]sCT(8-32) differs from the receptor-bound structure of the homologous ligands CGRP and AM. They all adopt an extended conformation followed by a C-terminal β turn, however, [BrPhe(22)]sCT(8-32) adopts a type II turn (Gly(28)-Thr(31)), whereas CGRP and AM adopt type I turns. Our results suggest that a type II turn is the preferred conformation of calcitonin, whereas a type I turn is the preferred conformation of peptides that require RAMPs; CGRP, AM, and amylin. In addition the structure provides a detailed molecular explanation and hypothesis regarding ligand binding properties of CTR and the amylin receptors.
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Affiliation(s)
- Eva Johansson
- From Novo Nordisk A/S, Novo Nordisk Park, DK-2760 Måløv, Denmark
| | | | | | | | - Peter Becker
- From Novo Nordisk A/S, Novo Nordisk Park, DK-2760 Måløv, Denmark
| | - Lauge Schäffer
- From Novo Nordisk A/S, Novo Nordisk Park, DK-2760 Måløv, Denmark
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50
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Emery AC, Alvarez RA, Abboud P, Xu W, Westover CD, Eiden MV, Eiden LE. C-terminal amidation of PACAP-38 and PACAP-27 is dispensable for biological activity at the PAC1 receptor. Peptides 2016; 79:39-48. [PMID: 26976270 PMCID: PMC4842133 DOI: 10.1016/j.peptides.2016.03.003] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/25/2015] [Revised: 01/30/2016] [Accepted: 03/09/2016] [Indexed: 01/29/2023]
Abstract
PACAP-27 and PACAP-38 are the exclusive physiological ligands for the mammalian PAC1 receptor. The role of C-terminal amidation of these ligands at that receptor was examined in neuroendocrine cells expressing the PAC1 receptor endogenously and in non-neuroendocrine cells in which the human and rat PAC1 receptors were expressed from stable single-copy genes driven by the CMV promoter, providing stoichiometrically appropriate levels of this Gs-coupled GPCR in order to examine the potency and intrinsic activity of PACAP ligands and their des-amidated congeners. We found that replacement of the C-terminal glycine residues of PACAP-27 and -38 with a free acid; or extension of either peptide with the two to three amino acids normally found at these positions in PACAP processing intermediates in vivo following endoproteolytic cleavage and after exoproteolytic trimming and glycine-directed amidated, were equivalent in potency to the fully processed peptides in a variety of cell-based assays. These included real-time monitoring of cyclic AMP generation in both NS-1 neuroendocrine cells and non-neuroendocrine HEK293 cells; PKA-dependent gene activation in HEK293 cells; and neuritogenesis and cell growth arrest in NS-1 cells. The specific implications for the role of amidation in arming of secretin-related neuropeptides for biological function, and the general implications for neuropeptide-based delivery in the context of gene therapy, are discussed.
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Affiliation(s)
- Andrew C Emery
- Section on Molecular Neuroscience, Laboratory of Cellular and Molecular Regulation, National Institute of Mental Health, Bethesda, MD 20892, USA
| | - Ryan A Alvarez
- Section on Molecular Neuroscience, Laboratory of Cellular and Molecular Regulation, National Institute of Mental Health, Bethesda, MD 20892, USA
| | - Philip Abboud
- Section on Molecular Neuroscience, Laboratory of Cellular and Molecular Regulation, National Institute of Mental Health, Bethesda, MD 20892, USA
| | - Wenqin Xu
- Section on Directed Gene Transfer, Laboratory of Cellular and Molecular Regulation, National Institute of Mental Health, Bethesda, MD 20892, USA
| | - Craig D Westover
- Section on Directed Gene Transfer, Laboratory of Cellular and Molecular Regulation, National Institute of Mental Health, Bethesda, MD 20892, USA
| | - Maribeth V Eiden
- Section on Directed Gene Transfer, Laboratory of Cellular and Molecular Regulation, National Institute of Mental Health, Bethesda, MD 20892, USA
| | - Lee E Eiden
- Section on Molecular Neuroscience, Laboratory of Cellular and Molecular Regulation, National Institute of Mental Health, Bethesda, MD 20892, USA.
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