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Clinical immunogenicity of the d -amino acid peptide therapeutic etelcalcetide: Method development challenges and anti-drug antibody clinical impact assessments. J Immunol Methods 2017; 445:37-44. [DOI: 10.1016/j.jim.2017.03.005] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2016] [Revised: 02/17/2017] [Accepted: 03/03/2017] [Indexed: 11/21/2022]
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Kanatsuna N, Taneera J, Vaziri-Sani F, Wierup N, Larsson HE, Delli A, Skärstrand H, Balhuizen A, Bennet H, Steiner DF, Törn C, Fex M, Lernmark Å. Autoimmunity against INS-IGF2 protein expressed in human pancreatic islets. J Biol Chem 2013; 288:29013-23. [PMID: 23935095 DOI: 10.1074/jbc.m113.478222] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Insulin is a major autoantigen in islet autoimmunity and progression to type 1 diabetes. It has been suggested that the insulin B-chain may be critical to insulin autoimmunity in type 1 diabetes. INS-IGF2 consists of the preproinsulin signal peptide, the insulin B-chain, and eight amino acids of the C-peptide in addition to 138 amino acids from the IGF2 gene. We aimed to determine the expression of INS-IGF2 in human pancreatic islets and autoantibodies in newly diagnosed children with type 1 diabetes and controls. INS-IGF2, expressed primarily in beta cells, showed higher levels of expression in islets from normal compared with donors with either type 2 diabetes (p = 0.006) or high HbA1c levels (p < 0.001). INS-IGF2 autoantibody levels were increased in newly diagnosed patients with type 1 diabetes (n = 304) compared with healthy controls (n = 355; p < 0.001). Displacement with cold insulin and INS-IGF2 revealed that more patients than controls had doubly reactive insulin-INS-IGF2 autoantibodies. These data suggest that INS-IGF2, which contains the preproinsulin signal peptide, the B-chain, and eight amino acids of the C-peptide may be an autoantigen in type 1 diabetes. INS-IGF2 and insulin may share autoantibody-binding sites, thus complicating the notion that insulin is the primary autoantigen in type 1 diabetes.
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Affiliation(s)
- Norio Kanatsuna
- From the Department of Clinical Sciences, Lund University Diabetes Center, Lund University, Skåne University Hospital SUS, SE-205 02 Malmö, Sweden and
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Correia M, Neves-Petersen MT, Jeppesen PB, Gregersen S, Petersen SB. UV-light exposure of insulin: pharmaceutical implications upon covalent insulin dityrosine dimerization and disulphide bond photolysis. PLoS One 2012; 7:e50733. [PMID: 23227203 PMCID: PMC3515625 DOI: 10.1371/journal.pone.0050733] [Citation(s) in RCA: 80] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2012] [Accepted: 10/24/2012] [Indexed: 12/11/2022] Open
Abstract
In this work we report the effects of continuous UV-light (276 nm, ~2.20 W.m(-2)) excitation of human insulin on its absorption and fluorescence properties, structure and functionality. Continuous UV-excitation of the peptide hormone in solution leads to the progressive formation of tyrosine photo-product dityrosine, formed upon tyrosine radical cross-linkage. Absorbance, fluorescence emission and excitation data confirm dityrosine formation, leading to covalent insulin dimerization. Furthermore, UV-excitation of insulin induces disulphide bridge breakage. Near- and far-UV-CD spectroscopy shows that UV-excitation of insulin induces secondary and tertiary structure losses. In native insulin, the A and B chains are held together by two disulphide bridges. Disruption of either of these bonds is likely to affect insulin's structure. The UV-light induced structural changes impair its antibody binding capability and in vitro hormonal function. After 1.5 and 3.5 h of 276 nm excitation there is a 33.7% and 62.1% decrease in concentration of insulin recognized by guinea pig anti-insulin antibodies, respectively. Glucose uptake by human skeletal muscle cells decreases 61.7% when the cells are incubated with pre UV-illuminated insulin during 1.5 h. The observations presented in this work highlight the importance of protecting insulin and other drugs from UV-light exposure, which is of outmost relevance to the pharmaceutical industry. Several drug formulations containing insulin in hexameric, dimeric and monomeric forms can be exposed to natural and artificial UV-light during their production, packaging, storage or administration phases. We can estimate that direct long-term exposure of insulin to sunlight and common light sources for indoors lighting and UV-sterilization in industries can be sufficient to induce irreversible changes to human insulin structure. Routine fluorescence and absorption measurements in laboratory experiments may also induce changes in protein structure. Structural damage includes insulin dimerization via dityrosine cross-linking or disulphide bond disruption, which affects the hormone's structure and bioactivity.
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Affiliation(s)
- Manuel Correia
- Department of Physics and Nanotechnology, Aalborg University, Aalborg, Denmark
| | - Maria Teresa Neves-Petersen
- International Iberian Nanotechnology Laboratory (INL), Braga, Portugal
- NanoBiotechnology Group, Department of Biotechnology, Chemistry and Environmental Sciences, Aalborg University, Aalborg, Denmark
- * E-mail:
| | - Per Bendix Jeppesen
- Aarhus University Hospital, Aarhus Sygehus THG, Department of Medicine and Endocrinology MEA, Aarhus C, Denmark
| | - Søren Gregersen
- Aarhus University Hospital, Aarhus Sygehus THG, Department of Medicine and Endocrinology MEA, Aarhus C, Denmark
| | - Steffen B. Petersen
- International Iberian Nanotechnology Laboratory (INL), Braga, Portugal
- NanoBiotechnology Group, Department of Health Science and Technology, Aalborg University, Aalborg, Denmark
- The Institute for Lasers, Photonics and Biophotonics, University at Buffalo, The State University of New York, Buffalo, New York, United States of America
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Kanatsuna N, Papadopoulos GK, Moustakas AK, Lenmark Å. Etiopathogenesis of insulin autoimmunity. ANATOMY RESEARCH INTERNATIONAL 2012; 2012:457546. [PMID: 22567309 PMCID: PMC3335545 DOI: 10.1155/2012/457546] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/02/2011] [Accepted: 01/12/2012] [Indexed: 12/12/2022]
Abstract
Autoimmunity against pancreatic islet beta cells is strongly associated with proinsulin, insulin, or both. The insulin autoreactivity is particularly pronounced in children with young age at onset of type 1 diabetes. Possible mechanisms for (pro)insulin autoimmunity may involve beta-cell destruction resulting in proinsulin peptide presentation on HLA-DR-DQ Class II molecules in pancreatic draining lymphnodes. Recent data on proinsulin peptide binding to type 1 diabetes-associated HLA-DQ2 and -DQ8 is reviewed and illustrated by molecular modeling. The importance of the cellular immune reaction involving cytotoxic CD8-positive T cells to kill beta cells through Class I MHC is discussed along with speculations of the possible role of B lymphocytes in presenting the proinsulin autoantigen over and over again through insulin-carrying insulin autoantibodies. In contrast to autoantibodies against other islet autoantigens such as GAD65, IA-2, and ZnT8 transporters, it has not been possible yet to standardize the insulin autoantibody test. As islet autoantibodies predict type 1 diabetes, it is imperative to clarify the mechanisms of insulin autoimmunity.
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Affiliation(s)
- Norio Kanatsuna
- Department of Clinical Sciences, Skåne University Hospital (SUS), Lund University, CRC Ing 72 Building 91:10, 205 02 Malmö, Sweden
| | - George K. Papadopoulos
- Laboratory of Biochemistry and Biophysics, Faculty of Agricultural Technology, Technological Educational Institute of Epirus, 47100 Arta, Greece
| | - Antonis K. Moustakas
- Department of Organic Farming, Technological Educational Institute of Ionian Islands, 27100 Argostoli, Greece
| | - Åke Lenmark
- Department of Clinical Sciences, Skåne University Hospital (SUS), Lund University, CRC Ing 72 Building 91:10, 205 02 Malmö, Sweden
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Grasso G, Rizzarelli E, Spoto G. The proteolytic activity of insulin-degrading enzyme: a mass spectrometry study. JOURNAL OF MASS SPECTROMETRY : JMS 2009; 44:735-741. [PMID: 19127548 DOI: 10.1002/jms.1550] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
The prominent role that insulin-degrading enzyme (IDE) has on amyloidogenic peptides degradation has recently boosted a lot of attention toward this enzyme. Although many substrates are known to be degraded by IDE, little is known about the changes in the proteolytic activity of the enzyme upon modification of environmental factors. In a previous work we have already shown the great potentiality of atmospheric pressure/laser desorption ionization-mass spectrometry (AP/MALDI-MS) for studying the interaction between IDE and insulin. Here, the activity of IDE was investigated regarding cleavage sites' preferentiality upon modification of environmental factors by AP/MALDI-MS. The roles that IDE/insulin concentration ratio, reaction time, adenosine 5'-triphosphate (ATP) and metal ions (Zn and Cu) have on the insulin cleavage pattern produced by IDE are investigated and a plausible interpretation involving the proteolytic action of the different IDE oligomeric forms is proposed.
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Affiliation(s)
- Giuseppe Grasso
- Dipartimento di Scienze Chimiche, Università di Catania, Viale Andrea Doria 6, 95125, Catania, Italy.
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Fuchs H, Gessner R. Iodination significantly influences the binding of human transferrin to the transferrin receptor. BIOCHIMICA ET BIOPHYSICA ACTA 2002; 1570:19-26. [PMID: 11960684 DOI: 10.1016/s0304-4165(02)00146-0] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The human transferrin receptor (TfR) and its ligand, the serum iron carrier transferrin, serve as a model system for endocytic receptors. Although the complete structure of the receptor's ectodomain and a partial structure of the ligand have been published, conflicting results still exist about the magnitude of equilibrium binding constants, possibly due to different labeling techniques. In the present study, we determined the equilibrium binding constant of purified human TfR and transferrin. The results were compared to those obtained with either iodinated TfR or transferrin. Using an enzyme-linked assay for receptor-ligand interactions based on the published direct calibration ELISA technique, we determined an equilibrium constant of Kd=0.22 nM for the binding of unmodified human Tf to surface-immobilized human TfR. In a reciprocal experiment using soluble receptor and surface-bound transferrin, a similar constant of Kd=0.23 nM was measured. In contrast, covalent labeling of either TfR or transferrin with 125I reduced the affinity 3-5-fold to Kd=0.66 nM and Kd=1.01 nM, respectively. The decrease in affinity upon iodination of transferrin is contrasted by an only 1.9-fold decrease in the association rate constant, suggesting that the iodination affects rather the dissociation than the association kinetics. These results indicate that precautions should be taken when interpreting equilibrium and rate constants determined with covalently labeled components.
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Affiliation(s)
- Hendrik Fuchs
- Institut für Laboratoriumsmedizin und Pathobiochemie, Medizinische Fakultät Charité der Humboldt-Universität zu Berlin, Campus Virchow-Klinikum, Augustenburger Platz 1, D-13353, Berlin, Germany
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Stumpo RR, Llera AS, Cardoso AI, Poskus E. Solid versus liquid phase assays in detection of insulin antibodies. Influence of iodination site on labelled insulin binding. J Immunol Methods 1994; 169:241-9. [PMID: 8133083 DOI: 10.1016/0022-1759(94)90268-2] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
On type 1 newly diagnosed and on insulin treated diabetic patients, anti-insulin autoantibodies (IAA) and antibodies (IA) having the same specificity are respectively induced. Such immune response may be evaluated either by radiobinding assay (RBA) or enzyme-linked immunosorbent assay (ELISA). Both methodologies have been compared at previous International Workshops, which pointed out discrepancies in results. In this work, IAA/IA prevalence was assessed by displacement RBA and ELISA, in normal subjects, type 2 (treated with hypoglycaemic agents), insulin treated and newly diagnosed type 1 diabetic patients. Results showed a lack of RBA-ELISA agreement. An attempt was then made to determine whether such results were, at least in part, attributable to iodination site in Tyr-A14. For this purpose parallel RBA assays were carried out by using radiolabelled insulin at A14 and A19 Tyr residues. Control sera and samples from insulin treated and type 1 newly diagnosed diabetic patients were tested. Our results suggest that labelling position is not involved in artifactual binding of tracers, at least as a systematic phenomenon. In the majority of cases the variability in RBA-ELISA signal ratios are best explained in terms of differences in the basic principles operating in both methods instead of artifacts due to tracer preparation.
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Affiliation(s)
- R R Stumpo
- Facultad de Farmacia y Bioquímica, Universidad de Buenos Aires, Department of Immunology, Argentina
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Vardi P, Brik R, Barzilai D. Insulin autoantibodies: reflection of disturbed self-identification and their use in the prediction of type I diabetes. DIABETES/METABOLISM REVIEWS 1991; 7:209-22. [PMID: 1813277 DOI: 10.1002/dmr.5610070402] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Affiliation(s)
- P Vardi
- Juvenile Diabetes Unit, Rambam Medical Center, Faculty of Medicine, Haifa, Israel
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