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Xiao B, Xiao J, Liu S, Xiao X, Dai S, Sui Y, Wu J, Ye H. Peroxynitrite scavenger FeTPPS binds with hCT to effectively inhibit its amyloid aggregation. Dalton Trans 2024. [PMID: 39355983 DOI: 10.1039/d4dt02214a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/03/2024]
Abstract
Human calcitonin (hCT) is an endogenous polypeptide commonly employed in treating bone resorption-related illnesses, but its clinical application is limited due to its high aggregation tendency. Metalloporphyrins are effective in suppressing amyloid fibrillation, positioning them as potential drug candidates for amyloidogenic disorders like Alzheimer's and type 2 diabetes. In this work, we investigated the effects of Fe(III) meso-tetra(4-sulfonatophenyl)porphine chloride (FeTPPS), a highly efficient ONOO- decomposition catalyst, on hCT aggregation. Our findings reveal that FeTPPS effectively precludes hCT fibrillation by stabilizing the monomers and delaying the structural transition from α-helix bundles to β-sheet-rich aggregates. The macrocyclic ring of FeTPPS plays a significant role in disrupting hCT self-associations. Among various porphyrin analogs, those with an iron center and negatively charged peripheral substituents exhibit a stronger inhibitory effect on hCT aggregation. Spectroscopic analyses and computational simulations indicate that FeTPPS binds to hCT's core aggregation region via complexation with His20 in a 1 : 1 molar ratio. Hydrophobic interaction, hydrogen bonding, and π-π stacking with the residues involving Tyr12, Phe19, and Ala26 also contribute to the interactions. Collectively, our study provides a promising approach for developing novel hCT drug formulations and offers theoretical guidance for designing metalloporphyrin-based inhibitors for various amyloidosis conditions.
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Affiliation(s)
- Bin Xiao
- School of Chemistry and Chemical Engineering, Key Laboratory of Jiangxi Province for Special Optoelectronic Artificial Crystal Materials, Jinggangshan University, Ji'an, Jiangxi 343009, P. R. China.
| | - Junhao Xiao
- School of Chemistry and Chemical Engineering, Key Laboratory of Jiangxi Province for Special Optoelectronic Artificial Crystal Materials, Jinggangshan University, Ji'an, Jiangxi 343009, P. R. China.
| | - Sisi Liu
- School of Chemistry and Chemical Engineering, Key Laboratory of Jiangxi Province for Special Optoelectronic Artificial Crystal Materials, Jinggangshan University, Ji'an, Jiangxi 343009, P. R. China.
| | - Xiaoying Xiao
- School of Chemistry and Chemical Engineering, Key Laboratory of Jiangxi Province for Special Optoelectronic Artificial Crystal Materials, Jinggangshan University, Ji'an, Jiangxi 343009, P. R. China.
| | - Shengping Dai
- School of Chemistry and Chemical Engineering, Key Laboratory of Jiangxi Province for Special Optoelectronic Artificial Crystal Materials, Jinggangshan University, Ji'an, Jiangxi 343009, P. R. China.
| | - Yan Sui
- School of Chemistry and Chemical Engineering, Key Laboratory of Jiangxi Province for Special Optoelectronic Artificial Crystal Materials, Jinggangshan University, Ji'an, Jiangxi 343009, P. R. China.
| | - Jinming Wu
- Department of Experimental Medical Science, Faculty of Medicine, Lund University, 22100, Lund, Sweden
| | - Huixian Ye
- School of Chemistry and Chemical Engineering, Key Laboratory of Jiangxi Province for Special Optoelectronic Artificial Crystal Materials, Jinggangshan University, Ji'an, Jiangxi 343009, P. R. China.
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Yan J, Wang Y, Fan X, Zou Y, Ding F, Huang F, Sun Y. Deciphering the influence of Y12L and N17H substitutions on the conformation and oligomerization of human calcitonin. SOFT MATTER 2024; 20:693-703. [PMID: 38164981 PMCID: PMC10845004 DOI: 10.1039/d3sm01332d] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/03/2024]
Abstract
The abnormal aggregation of human calcitonin (hCT) hormone peptides impairs their physiological function, leading to harmful immune responses and cytotoxicity, which limits their clinical utility. Interestingly, a representative hCT analog incorporating Y12L and N17H substitutions (DM-hCT) has shown reduced aggregation tendencies while maintaining bioactivity. But the molecular mechanism of Y12L and N17H substitutions on the conformational dynamics of hCT remains unclear. Here, we systematically investigated the folding and self-assembly dynamics of hCT and DM-hCT using atomistic discrete molecular dynamics (DMD) simulations. Our findings revealed that hCT monomers predominantly adopted unstructured conformations with dynamic helices. Oligomerization of hCT resulted in the formation of β-sheet-rich aggregates and β-barrel intermediates. The Y12L and N17H substitutions enhanced helical conformations and suppressed β-sheet formation in both monomers and oligomers. These substitutions stabilized the dynamic helices and disrupted aromatic interactions responsible for β-sheet formation at residue 12. Notably, DM-hCT assemblies still exhibited β-sheets in phenylalanine-rich and C-terminal hydrophobic regions, suggesting that future optimizations should focus on these areas. Our simulations provide insights into the molecular mechanisms underlying hCT aggregation and the amyloid-resistant effects of Y12L and N17H substitutions. These findings have valuable implications for the development of clinical hCT analogs.
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Affiliation(s)
- Jiajia Yan
- School of Physical Science and Technology, Ningbo University, Ningbo 315211, China.
- Ningbo Institute of Innovation for Combined Medicine and Engineering (NIIME), Ningbo Medical Center Lihuili Hospital, Ningbo 315211, China.
| | - Ying Wang
- School of Physical Science and Technology, Ningbo University, Ningbo 315211, China.
| | - Xinjie Fan
- School of Physical Science and Technology, Ningbo University, Ningbo 315211, China.
| | - Yu Zou
- Department of Sport and Exercise Science, Zhejiang University, Hangzhou 310058, China
| | - Feng Ding
- Department of Physics and Astronomy, Clemson University, Clemson, SC 29634, USA.
| | - Fengjuan Huang
- Ningbo Institute of Innovation for Combined Medicine and Engineering (NIIME), Ningbo Medical Center Lihuili Hospital, Ningbo 315211, China.
| | - Yunxiang Sun
- School of Physical Science and Technology, Ningbo University, Ningbo 315211, China.
- Department of Physics and Astronomy, Clemson University, Clemson, SC 29634, USA.
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Liu Y, Wang Y, Zhang Y, Zou Y, Wei G, Ding F, Sun Y. Structural Perturbation of Monomers Determines the Amyloid Aggregation Propensity of Calcitonin Variants. J Chem Inf Model 2023; 63:308-320. [PMID: 36456917 PMCID: PMC9839651 DOI: 10.1021/acs.jcim.2c01202] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/04/2022]
Abstract
Human calcitonin (hCT) is a polypeptide hormone that participates in calcium-phosphorus metabolism. Irreversible aggregation of 32-amino acid hCT into β-sheet-rich amyloid fibrils impairs physiological activity and increases the risk of medullary carcinoma of the thyroid. Amyloid-resistant hCT derivatives substituting critical amyloidogenic residues are of particular interest for clinical applications as therapeutic drugs against bone-related diseases. Uncovering the aggregation mechanism of hCT at the molecular level, therefore, is important for the design of amyloid-resistant hCT analogues. Here, we investigated the aggregation dynamics of hCT, non-amyloidogenic salmon calcitonin (sCT), and two hCT analogues with reduced aggregation tendency─TL-hCT and phCT─using long timescale discrete molecular dynamics simulations. Our results showed that hCT monomers mainly adopted unstructured conformations with dynamically formed helices around the central region. hCT self-assembled into helix-rich oligomers first, followed by a conformational conversion into β-sheet-rich oligomers with β-sheets formed by residues 10-30 and stabilized by aromatic and hydrophobic interactions. Our simulations confirmed that TL-hCT and phCT oligomers featured more helices and fewer β-sheets than hCT. Substitution of central aromatic residues with leucine in TL-hCT and replacing C-terminal hydrophobic residue with hydrophilic amino acid in phCT only locally suppressed β-sheet propensities in the central region and C-terminus, respectively. Having mutations in both central and C-terminal regions, sCT monomers and dynamically formed oligomers predominantly adopted helices, confirming that both central aromatic and C-terminal hydrophobic residues played important roles in the fibrillization of hCT. We also observed the formation of β-barrel intermediates, postulated as the toxic oligomers in amyloidosis, for hCT but not for sCT. Our computational study depicts a complete picture of the aggregation dynamics of hCT and the effects of mutations. The design of next-generation amyloid-resistant hCT analogues should consider the impact on both amyloidogenic regions and also take into account the amplification of transient β-sheet population in monomers upon aggregation.
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Affiliation(s)
- Yuying Liu
- Department of Physics, Ningbo University, Ningbo 315211, China
- State Key Laboratory of Surface Physics and Department of Physics, Fudan University, Shanghai 200433, P. R. China
| | - Ying Wang
- Department of Physics, Ningbo University, Ningbo 315211, China
| | - Yu Zhang
- Department of Physics, Ningbo University, Ningbo 315211, China
| | - Yu Zou
- Department of Sport and Exercise Science, Zhejiang University, Hangzhou 310058, China
| | - Guanghong Wei
- State Key Laboratory of Surface Physics and Department of Physics, Fudan University, Shanghai 200433, P. R. China
| | - Feng Ding
- Department of Physics and Astronomy, Clemson University, Clemson, SC 29634, USA
| | - Yunxiang Sun
- Department of Physics, Ningbo University, Ningbo 315211, China
- State Key Laboratory of Surface Physics and Department of Physics, Fudan University, Shanghai 200433, P. R. China
- Department of Physics and Astronomy, Clemson University, Clemson, SC 29634, USA
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Wong A, Nabata K, Wiseman SM. Medullary thyroid carcinoma: a narrative historical review. Expert Rev Anticancer Ther 2022; 22:823-834. [PMID: 35694971 DOI: 10.1080/14737140.2022.2089118] [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: 11/04/2022]
Abstract
INTRODUCTION Sporadic or hereditary medullary thyroid carcinoma (MTC) is an uncommon thyroid malignancy arising from calcitonin secreting parafollicular C cells. Interestingly, MTC and calcitonin were distinct entities that were discovered independently yet concurrently, and their association was unknown. AREAS COVERED This review aims to present a historical review of the evolution of our understanding of MTC and its tumor marker calcitonin to highlight the prominent individuals that influenced and shaped our knowledge of this uncommon thyroid cancer type up to the dawn of the 21st century. An overview of all published reports of novel research and work summarizing important findings for MTC and calcitonin was carried out. EXPERT OPINION Surgery remains the cornerstone of treatment for localized MTC. However, several new treatment options are either available or in development for advanced or metastatic MTC, including several novel small molecules targeting oncogenic RET and peptide receptor radionuclide therapy, immunotherapy, radioimmunotherapy, and radiofrequency ablation. In the near future, these novel treatments hold promise for therapy of this very distinct thyroid cancer type.
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Affiliation(s)
- Amanda Wong
- Department of Surgery, St. Paul's Hospital & University of British Columbia, Vancouver, British Columbia, Canada
| | - Kylie Nabata
- Department of Surgery, St. Paul's Hospital & University of British Columbia, Vancouver, British Columbia, Canada
| | - Sam M Wiseman
- Department of Surgery, St. Paul's Hospital & University of British Columbia, Vancouver, British Columbia, Canada
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Kaneb A, Berardino K, Hanukaai JS, Rooney K, Kaye AD. Calcitonin (FORTICAL, MIACALCIN) for the treatment of vertebral compression fractures. Orthop Rev (Pavia) 2021; 13:24976. [PMID: 34745472 DOI: 10.52965/001c.24976] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/15/2021] [Accepted: 06/18/2021] [Indexed: 12/28/2022] Open
Abstract
Purpose of Review Osteoporosis is a common condition affecting the musculoskeletal system. It carries with it increased risks of fracture in many areas of the body, leading to reduced quality of life, limited mobility, and other long-term implications such as chronic pain. Vertebral compression fractures are a common development in patients with osteoporosis. Current treatment options focus on reducing pain; preventative methods are somewhat limited and focus on minimizing risk factors for the development of osteoporosis. In this review, we explore the use of calcitonin (FORTICAL, MIACALCIN) to treat vertebral compression fractures (VCFs). Recent Findings Osteoporosis had a prevalence of more than 10% in the United States in 2010. The CDC estimates that nearly 25% of women over age 65 have findings of osteoporosis, which include low spinal bone mass. The condition is highly prevalent and, in an aging U.S. population, quite clinically relevant. Risk factors for development include advanced age, cigarette smoking, medications, reduced physical activity, and low calcium and vitamin D intake. Family history may also play a role. Diagnosis is made based on bone mineral density.Standard therapy for VCFs in osteoporosis includes analgesic medications, such as NSAIDs and biphosphonates, and surgical intervention. NSAIDs address the chronic pain that is a common long-term effect of VCFs. Biphosphonates have recently been used to attempt to halt the progression and provide prevention. Surgical interventions such as balloon kyphoplasty and vertebroplasty are typically reserved for patients who have failed other methods.Calcitonin is a peptide naturally produced by the human body, released from the parathyroid gland. It binds to osteoclasts, inhibiting them from inducing bone resorption. By relatively unknown mechanisms, it also appears to cause endorphin release and mitigate pain. Clinical data has shown safety and efficacy for exogenous calcitonin in reducing bone turnover and reducing VCF-induced pain. Summary Osteoporosis is a common condition that can lead to complications such as vertebral compression fractures. It can significantly impact the quality of life in many elderly Americans. There is currently no singular treatment, but calcitonin has recently been explored as a possible option for minimizing pain and reducing disease progression. Further studies are needed to understand its preventative benefits fully.
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Affiliation(s)
- Alicia Kaneb
- Georgetown University School of Medicine, Washington D.C
| | | | | | - Kelsey Rooney
- Louisiana State University Health Science Center, Shreveport, LA
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Merlotti D, Materozzi M, Picchioni T, Bianciardi S, Alessandri M, Nuti R, Gennari L. Recent advances in models for screening potential osteoporosis drugs. Expert Opin Drug Discov 2018; 13:741-752. [PMID: 29869573 DOI: 10.1080/17460441.2018.1480609] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
INTRODUCTION Osteoporosis is a growing health and health-economic problem due to the increased proportion of elderly people in the population. Basic and clinical advances in research over the past two decades have led to the development of different compounds with antiresorptive or anabolic activity on bone that improved substantially the management of patients with osteoporosis over calcitonin or estrogen replacement. New compounds are in preclinical and clinical development. Areas covered: In this review, the authors review the approaches for the preclinical and clinical development of antiresorptive and anabolic agents for osteoporosis, particularly focusing on the recent advances in technology and in the understanding of skeletal biology, together with their implications on novel osteoporosis drug discovery. Expert opinion: Based on the available evidence from the approved drugs for the treatment osteoporosis as well as from the different compounds under clinical development, it has become clear that long term nonclinical pharmacological studies with either bone quality and off-target effects as the main outcomes should be required for new drugs intended to treat osteoporosis. At the same time, basic and clinical advances in research have underlined the necessity to develop new technologies and new models for a thorough screening of the effects of new drugs on the different components of skeletal aging and bone fragility that cannot be assessed by bone mass measurement.
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Affiliation(s)
- D Merlotti
- a Department of Medicine, Surgery and Neurosciences , University of Siena, Policlinico Santa Maria alle Scotte , Siena , Italy.,b Division of Genetics and Cell Biology , San Raffaele Hospital , Milan , Italy
| | - M Materozzi
- a Department of Medicine, Surgery and Neurosciences , University of Siena, Policlinico Santa Maria alle Scotte , Siena , Italy
| | - T Picchioni
- a Department of Medicine, Surgery and Neurosciences , University of Siena, Policlinico Santa Maria alle Scotte , Siena , Italy
| | - S Bianciardi
- a Department of Medicine, Surgery and Neurosciences , University of Siena, Policlinico Santa Maria alle Scotte , Siena , Italy
| | - M Alessandri
- a Department of Medicine, Surgery and Neurosciences , University of Siena, Policlinico Santa Maria alle Scotte , Siena , Italy
| | - R Nuti
- a Department of Medicine, Surgery and Neurosciences , University of Siena, Policlinico Santa Maria alle Scotte , Siena , Italy
| | - L Gennari
- a Department of Medicine, Surgery and Neurosciences , University of Siena, Policlinico Santa Maria alle Scotte , Siena , Italy
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Inhibitory effects of magnolol and honokiol on human calcitonin aggregation. Sci Rep 2015; 5:13556. [PMID: 26324190 PMCID: PMC4555095 DOI: 10.1038/srep13556] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2015] [Accepted: 07/30/2015] [Indexed: 02/07/2023] Open
Abstract
Amyloid formation is associated with multiple amyloidosis diseases. Human calcitonin (hCT) is a typical amyloidogenic peptide, its aggregation is associated with medullary carcinoma of the thyroid (MTC), and also limits its clinical application. Magnolia officinalis is a traditional Chinese herbal medicine; its two major polyphenol components, magnolol (Mag) and honokiol (Hon), have displayed multiple functions. Polyphenols like flavonoids and their derivatives have been extensively studied as amyloid inhibitors. However, the anti-amyloidogenic property of a biphenyl backbone containing polyphenols such as Mag and Hon has not been reported. In this study, these two compounds were tested for their effects on hCT aggregation. We found that Mag and Hon both inhibited the amyloid formation of hCT, whereas Mag showed a stronger inhibitory effect; moreover, they both dose-dependently disassembled preformed hCT aggregates. Further immuno-dot blot and dynamic light scattering studies suggested Mag and Hon suppressed the aggregation of hCT both at the oligomerization and the fibrillation stages, while MTT-based and dye-leakage assays demonstrated that Mag and Hon effectively reduced cytotoxicity caused by hCT aggregates. Furthermore, isothermal titration calorimetry indicated Mag and Hon both interact with hCT. Together, our study suggested a potential anti-amyloidogenic property of these two compounds and their structure related derivatives.
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Wylie CD. Setting a standard for a "silent" disease: defining osteoporosis in the 1980s and 1990s. STUDIES IN HISTORY AND PHILOSOPHY OF BIOLOGICAL AND BIOMEDICAL SCIENCES 2010; 41:376-385. [PMID: 21112012 DOI: 10.1016/j.shpsc.2010.10.015] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
Osteoporosis, a disease of bone loss associated with aging and estrogen loss, can be crippling but is 'silent' (symptomless) prior to bone fracture. Despite its disastrous health effects, high prevalence, and enormous associated health care costs, osteoporosis lacked a universally accepted definition until 1992. In the 1980s, the development of more accurate medical imaging technologies to measure bone density spurred the medical community's need and demand for a common definition. The medical community tried, and failed, to resolve these differing definitions several times at consensus conferences and through published articles. These experts finally accepted a standard definition at an international consensus conference convened by the World Health Organization in 1992. The construction of osteoporosis as a disease of quantifiable risk diagnosed by medical imaging machines reflects contemporary trends in medicine, including the quantification of disease, the risk factor model, medical disciplinary boundaries, and global standardization of medical knowledge.
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Affiliation(s)
- Caitlin Donahue Wylie
- Department of History and Philosophy of Science, University of Cambridge, Free School Lane, Cambridge, CB2 3RH, United Kingdom.
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Leader B, Baca QJ, Golan DE. Protein therapeutics: a summary and pharmacological classification. Nat Rev Drug Discov 2008; 7:21-39. [PMID: 18097458 DOI: 10.1038/nrd2399] [Citation(s) in RCA: 1381] [Impact Index Per Article: 86.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Once a rarely used subset of medical treatments, protein therapeutics have increased dramatically in number and frequency of use since the introduction of the first recombinant protein therapeutic--human insulin--25 years ago. Protein therapeutics already have a significant role in almost every field of medicine, but this role is still only in its infancy. This article overviews some of the key characteristics of protein therapeutics, summarizes the more than 130 protein therapeutics used currently and suggests a new classification of these proteins according to their pharmacological action.
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Affiliation(s)
- Benjamin Leader
- Department of Emergency Medicine, Brown Medical School, 593 Eddy Street, Providence, Rhode Island 02093, USA
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Rennert R, Neundorf I, Beck-Sickinger AG. Calcitonin-derived peptide carriers: mechanisms and application. Adv Drug Deliv Rev 2008; 60:485-98. [PMID: 18160173 DOI: 10.1016/j.addr.2007.09.008] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2007] [Accepted: 09/04/2007] [Indexed: 01/16/2023]
Abstract
Among the family of the so-called cell-penetrating peptides (CPP) sequences derived from the native peptide hormone human calcitonin (hCT) have recently proven to translocate different bioactive molecules across cellular membranes. Herein, we give an extensive summary of the development of hCT-derived carrier peptides, beginning with the therapeutic nasal administration of full-length hCT. Hence, N-terminally truncated hCT fragments were investigated and subsequently optimised to extend their field of application. The latest generation of hCT-derived carrier peptides are highly effective, branched peptides. The current state of the art is reviewed concerning the structural requirements, mechanistic assumptions and metabolic features of these peptides as well as experiments proving their excellent carrier potential.
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Affiliation(s)
- Robert Rennert
- Institute of Biochemistry, Faculty of Bioscience, Pharmacy and Psychology, Leipzig University, Brüderstr. 34, D-04103 Leipzig, Germany
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Wagner K, Van Mau N, Boichot S, Kajava AV, Krauss U, Le Grimellec C, Beck-Sickinger A, Heitz F. Interactions of the human calcitonin fragment 9-32 with phospholipids: a monolayer study. Biophys J 2004; 87:386-95. [PMID: 15240473 PMCID: PMC1304360 DOI: 10.1529/biophysj.103.036921] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2003] [Accepted: 03/26/2004] [Indexed: 11/18/2022] Open
Abstract
Human calcitonin and its C-terminal fragment 9-32 (hCT(9-32)) administered in a spray translocate into respiratory nasal epithelium with an effect similar to intravenous injection. hCT(9-32) is an efficient carrier to transfer the green fluorescent protein into excised bovine nasal mucosa. To understand the translocation of hCT(9-32) across plasma membranes, we investigated its interactions with phospholipids and its interfacial structure using model lipid monolayers. A combination of physicochemical methods was applied including surface tension measurements on adsorbed and spread monolayers at the air-water interface, Fourier transform infrared, circular dichroism, and atomic force microscopy on Langmuir-Blodgett monolayers. The results disclose that hCT(9-32) preferentially interacts with negatively charged phospholipids and does not insert spontaneously into lipid monolayers. This supports a nonreceptor-mediated endocytic internalization pathway as previously suggested. Structural studies revealed a random coil conformation of hCT(9-32) in solution, transforming to alpha-helices when the peptide is localized at lipid-free or lipid-containing air-water interfaces. Atomic force microscopy studies of monolayers of the peptide alone or mixed with dioleoylphosphatidylcholine revealed that hCT(9-32) forms filaments rolled into spirals. In contrast, when interacting with dioleoylphosphatidylglycerol, hCT(9-32) does not adopt filamentous structures. A molecular model and packing is proposed for the spiral-forming hCT(9-32).
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Affiliation(s)
- Kerstin Wagner
- Centre de Recherches de Biochimie Macromoléculaire-Centre National de la Recherche Scientifique, Formation de Recherche en Evolution 2593, F-34293 Montpellier Cedex, France
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Irmak MK, Kirici Y. Time to reevaluate the therapeutic use of calcitonin and biological role attributable to parafollicular (C) cells. Med Hypotheses 2004; 62:425-30. [PMID: 14975516 DOI: 10.1016/s0306-9877(03)00341-4] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2003] [Accepted: 11/10/2003] [Indexed: 11/29/2022]
Abstract
There is rich anecdotal evidence that calcitonin significantly increases bone mineral density and reduces fracture risk. However, observation in a previous study of an increased bone formation in calcitonin-deficient mice has led us to reevaluate the therapeutic use of calcitonin and to investigate the primary role of parafollicular (C) cells of the thyroid gland. We found that C cells are involved mainly in the regulation of follicular cell activity in a paracrine manner and in doing so they may regulate the growth rate in newborn by affecting the thyroid hormone levels in the early postnatal period. In the light of reports that showed thyroid physiology is different between populations and it is affected by environmental factors we suggested that C cells may be involved in population differences in thyroid physiology and environmental adaptation. We conclude that C cells may facilitate the adaptation of the follicular cells to environmental changes, enabling more effective coordinated functions of the body and producing variations between populations.
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Affiliation(s)
- M K Irmak
- Department of Histology - Embryology, Gulhane Military Medical Academy, Ankara, Turkey.
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Abstract
In December 1979, the Food and Drug Administration's (FDA) Division of Metabolic and Endocrine Drug Products issued its Guidelines for the Clinical Evaluation of Drugs Used in the Treatment of Osteoporosis. The Guidance Document recommended study designs, patient populations for study, and techniques for evaluating skeletal mass and fracture frequency that were considered central to showing the efficacy and safety of drugs used to treat and prevent postmenopausal osteoporosis (PMO). In this paper, I discuss the evolution of the Osteoporosis Guidance as it relates to the pharmaceutical industry's efforts to develop effective and safe anti-osteoporosis drugs. Current regulatory policy on osteoporosis drugs and thoughts on the future direction of the Osteoporosis Guidance are also provided.
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Affiliation(s)
- Eric G Colman
- U.S. Department of Health and Human Services, Food and Drug Administration, Center for Drug Evaluation and Research, Division of Metabolic and Endocrine Drug Products, Rockville, Maryland 20857, USA.
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Zaidi M, Moonga BS, Abe E. Calcitonin and bone formation: a knockout full of surprises. J Clin Invest 2003. [PMID: 12488426 DOI: 10.1172/jci200217425] [Citation(s) in RCA: 61] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Affiliation(s)
- Mone Zaidi
- Mount Sinai Bone Program, Mount Sinai School of Medicine, New York, New York, USA.
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Zaidi M, Moonga BS, Abe E. Calcitonin and bone formation: a knockout full of surprises. J Clin Invest 2002; 110:1769-71. [PMID: 12488426 PMCID: PMC151662 DOI: 10.1172/jci17425] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Affiliation(s)
- Mone Zaidi
- Mount Sinai Bone Program, Mount Sinai School of Medicine, New York, New York, USA.
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17
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Chesnut CH. History of calcitonin. Lancet 2002; 360:801. [PMID: 12241848 DOI: 10.1016/s0140-6736(02)09911-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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