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Wallukat G, Jandrig B, Becker NP, Wendler JJ, Göttel P, Müller J, Schostak M, Schimke I. Autoantibodies directed against α1-adrenergic receptor and endothelin receptor A in patients with prostate cancer. AUTOIMMUNITY HIGHLIGHTS 2020; 11:13. [PMID: 32977857 PMCID: PMC7519497 DOI: 10.1186/s13317-020-00136-y] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/08/2020] [Accepted: 07/20/2020] [Indexed: 01/12/2023]
Abstract
BACKGROUND For prostate cancer, signaling pathways induced by over-boarding stimulation of G-protein coupled receptors (GPCR) such as the endothelin, α1- and β-adrenergic, muscarinic and angiotensin 1 receptors were accused to support the carcinogenesis. However, excessive receptor stimulation by physiological receptor ligands is minimized by a control system that induces receptor sensitization and down-regulation. This system is missing when so-called "functional autoantibodies" bind to the GPCR (GPCR-AAB). If GPCR-AAB were found in patients with prostate cancer, uncontrolled GPCR stimulation could make these autoantibodies an additional supporter in prostate cancer. METHODS Using the bioassay of spontaneously beating cultured rat neonatal cardiomyocytes, GPCR-AAB were identified, quantified and characterized in the serum of 25 patients (aged 56-78 years, median 70 years) with prostate cancer compared to 10 male patients (aged 48-82 years, median 64) with urinary stone disorders (controls). RESULTS Of the cancer patients, 24 (96%) and 17 (68%), respectively, carried autoantibodies directed against the α1-adrenergic receptor (α1-AAB) and endothelin receptor A (ETA-AAB). No patient was negative for both GPCR-AAB. In contrast, ETA-AAB and α1-AAB were absent in all (100%) and 9 (90%) of the 10 control patients, respectively. While α1-AAB targeted a specific epitope of the first extracellular loop of the α1-adrenergic receptor subtype A, an epitope of the second extracellular loop of the ETA receptor was identified as a target of ETA-AAB. As demonstrated in vitro, the functional activity of both autoantibodies found in prostate cancer can be neutralized by the aptamer BC007. CONCLUSIONS We hypothesized that α1-AAB and ETA-AAB, which are highly present in prostate cancer patients, could by their functional activity support carcinogenesis by excessive receptor stimulation. The in vitro demonstrated neutralization of α1- and ETA-AAB by the aptamer BC007 could open the door to complement the treatments already available for prostate cancer.
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Affiliation(s)
- Gerd Wallukat
- Berlin Cures GmbH, Knesebeckstraße 59-61, 10719, Berlin, Germany
| | - Burkhard Jandrig
- Universitätsklinik für Urologie, Uroonkologie, robotergestützte und fokale Therapie, Otto von Guericke Universität, Magdeburg, Germany
| | | | - Johann J Wendler
- Universitätsklinik für Urologie, Uroonkologie, robotergestützte und fokale Therapie, Otto von Guericke Universität, Magdeburg, Germany
| | - Peter Göttel
- Berlin Cures GmbH, Knesebeckstraße 59-61, 10719, Berlin, Germany
| | - Johannes Müller
- Berlin Cures GmbH, Knesebeckstraße 59-61, 10719, Berlin, Germany
| | - Martin Schostak
- Universitätsklinik für Urologie, Uroonkologie, robotergestützte und fokale Therapie, Otto von Guericke Universität, Magdeburg, Germany
| | - Ingolf Schimke
- Berlin Cures GmbH, Knesebeckstraße 59-61, 10719, Berlin, Germany.
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Cardiomyopathy - An approach to the autoimmune background. Autoimmun Rev 2017; 16:269-286. [PMID: 28163240 DOI: 10.1016/j.autrev.2017.01.012] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2016] [Accepted: 11/20/2016] [Indexed: 12/15/2022]
Abstract
Autoimmunity is increasingly accepted as the origin or amplifier of various diseases. In contrast to classic autoantibodies (AABs), which induce immune responses resulting in the destruction of the affected tissue, an additional class of AABs is directed against G-protein-coupled receptors (GPCRs; GPCR-AABs). GPCR-AABs functionally affect their related GPCRs for activation of receptor mediated signal cascades. Diseases which are characterized by the presence of GPCR-AABs with evidence for disease-specific pathogenic activity could be named "functional autoantibody disease". We briefly summarize here the historical view on autoimmunity in cardiomyopathy, followed by an approach to the mechanistic autoimmunity background. Furthermore, autoantibodies with outstanding importance for cardiomyopathies as a functional autoantibody disease, such as GPCR-AABs, and mainly those directed against the beta1-adrenergic and muscarinic 2 receptor autoantibodies, are introduced. Anti-cardiac myosin and anti-cardiac troponin autoantibodies, as further potential players in autoimmune cardiomyopathy, are additionally taken into account. The basic view on the autoantibodies, their related receptor interactions and pathogenic consequences are presented. Focused specifically on GPCR-AABs, "pros and cons" of assays such as indirect assays (functional changes of cell preparations are monitored after GPCR-AAB receptor binding) and direct assays based on the ELISA technologies (GPCR epitope mimics for GPCR-AAB binding) are critically discussed. Last but not least, treatment strategies for "functional autoantibody disease", such as for GPCR-AAB removal (therapeutic plasma exchange, immunoadsorption) and in vivo GPCR-AAB attack such as intravenous IgG treatment (IVIG), B-cell depletion and GPCR-AAB binding and neutralization, are critically reflected with respect to their patient benefits.
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Functional autoantibodies in systemic sclerosis. Semin Immunopathol 2015; 37:529-42. [DOI: 10.1007/s00281-015-0513-5] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2015] [Accepted: 07/06/2015] [Indexed: 12/29/2022]
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Agonistic autoantibodies directed against G-protein-coupled receptors and their relationship to cardiovascular diseases. Semin Immunopathol 2014; 36:351-63. [PMID: 24777744 DOI: 10.1007/s00281-014-0425-9] [Citation(s) in RCA: 80] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2014] [Accepted: 04/01/2014] [Indexed: 02/06/2023]
Abstract
Agonistic autoantibodies (AABs) against G-protein-coupled receptor (GPCR) are present mainly in diseases of the cardiovascular system or in diseases associated with cardiovascular disturbances. The increasing knowledge about the role of autoantibodies against G-protein-coupled receptor (GPCR-AABs) as pathogenic drivers, the resulting development of strategies aimed at their removal or neutralization, and the evidenced patient benefit associated with such therapies have created the need for a summary of GPCR-AAB-associated diseases. Here, we summarize the present knowledge about GPCR-AABs in cardiovascular diseases. The identity of the GPCR-AABs and their prevalence in each of several specific cardiovascular diseases are documented. The structure of GPCR is also briefly discussed. Using this information, differences between classic agonists and GPCR-AABs in their GPCR binding and activation are presented and the resulting pathogenic consequences are discussed. Furthermore, treatment strategies that are currently under study, most of which are aimed at the removal and in vivo neutralization of GPCR-AABs, are indicated and their patient benefits discussed. In this context, immunoadsorption using peptides/proteins or aptamers as binders are introduced. The use of peptides or aptamers for in vivo neutralization of GPCR-AABs is also described. Particular attention is given to the GPCR-AABs directed against the adrenergic beta1-, beta2-, and α1-receptor as well as the muscarinic receptor M2, angiotensin II-angiotensin receptor type I, endothelin1 receptor type A, angiotensin (1-7) Mas-receptor, and 5-hydroxytryptamine receptor 4. Among the diseases associated with GPCR-AABs, special focus is given to idiopathic dilated cardiomyopathy, Chagas' cardiomyopathy, malignant and pulmonary hypertension, and kidney diseases. Relationships of GPCR-AABs are indicated to glaucoma, peripartum cardiomyopathy, myocarditis, pericarditis, preeclampsia, Alzheimer's disease, Sjörgren's syndrome, and metabolic syndrome after cancer chemotherapy.
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Buvall L, Täng MS, Isic A, Andersson B, Fu M. Antibodies against the β1-adrenergic receptor induce progressive development of cardiomyopathy. J Mol Cell Cardiol 2007; 42:1001-7. [PMID: 17362986 DOI: 10.1016/j.yjmcc.2007.02.007] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/05/2006] [Revised: 01/12/2007] [Accepted: 02/08/2007] [Indexed: 10/23/2022]
Abstract
Different immune disturbances have been found among patients with dilated cardiomyopathy (DCM), including antibodies directed against different cardiac antigens, such as the second extracellular loop of the beta(1)-adrenergic receptor. The aim of our study was to investigate antibodies directed against the second extracellular loop of the beta(1)-adrenergic receptor effect on cardiac functions at an early and late stage during DCM development. This was made in a mouse model, in which DCM was induced by immunization with the second extracellular loop of the beta(1)-adrenergic receptor. Mice were immunized for 14 or 25 weeks respectively with the second extracellular loop of the beta(1)-adrenergic receptor. At 14 weeks, there was no decreased heart function reviled by echocardiography at rest, but when dobutamine stress echocardiography was used, a lower cardiac reserve was shown in the mice with antibodies against the second extracellular loop of the beta(1)-adrenergic receptor. By 25 weeks, decreased heart function, dilatation of the left ventricle and thinner left ventricular posterior wall were observed. Further biochemical analyses at 25 weeks showed increased mRNA expressions for beta(1)-adrenergic receptor kinase, monocyte chemoattractant protein-1 and the brain natriuretic peptide as well as increased concentrations of complement factor 3 in sera in the immunized animals. Our data suggest a cardiotoxic effect of antibodies directed against the second extracellular loop of the beta(1)-adrenergic receptor and a capacity to induce DCM with progressive remodeling, decreased cardiac function, altered beta(1)AR signaling and upregulation of proinflammatory components.
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Affiliation(s)
- Lisa Buvall
- Department of Molecular and Clinical Medicine/Cardiology, Institute of Medicine, Sahlgrenska Academy, University of Göteborg, Sweden.
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Insel PA, Tang CM, Hahntow I, Michel MC. Impact of GPCRs in clinical medicine: monogenic diseases, genetic variants and drug targets. BIOCHIMICA ET BIOPHYSICA ACTA 2007; 1768:994-1005. [PMID: 17081496 PMCID: PMC2169201 DOI: 10.1016/j.bbamem.2006.09.029] [Citation(s) in RCA: 127] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/27/2006] [Revised: 09/28/2006] [Accepted: 09/29/2006] [Indexed: 12/15/2022]
Abstract
By virtue of their large number, widespread distribution and important roles in cell physiology and biochemistry, G-protein-coupled receptors (GPCR) play multiple important roles in clinical medicine. Here, we focus on 3 areas that subsume much of the recent work in this aspect of GPCR biology: (1) monogenic diseases of GPCR; (2) genetic variants of GPCR; and (3) clinically useful pharmacological agonists and antagonists of GPCR. Diseases involving mutations of GPCR are rare, occurring in <1/1000 people, but disorders in which antibodies are directed against GPCR are more common. Genetic variants, especially single nucleotide polymorphisms (SNPs), show substantial heterogeneity in frequency among different GPCRs but have not been evaluated for some GPCR. Many therapeutic agonists and antagonists target GPCR and show inter-subject variability in terms of efficacy and toxicity. For most of those agents, it remains an open question whether genetic variation in primary sequence of the GPCR is an important contributor to such inter-subject variability, although this is an active area of investigation.
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Affiliation(s)
- Paul A Insel
- University of California San diego, Department of Pharmacology, La Jolla, CA 92093-0636, USA.
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Betz SF, Reinhart GJ, Lio FM, Chen C, Struthers RS. Overlapping, Nonidentical Binding Sites of Different Classes of Nonpeptide Antagonists for the Human Gonadotropin-Releasing Hormone Receptor. J Med Chem 2005; 49:637-47. [PMID: 16420049 DOI: 10.1021/jm0506928] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Peptide agonists and antagonists of the human gonadotropin-releasing hormone receptor (GnRH-R) are widely used to treat a range of reproductive hormone related diseases. Recently, nonpeptide, orally available GnRH-R antagonists have emerged from several chemical classes. To understand how a relatively large peptide-binding pocket can recognize numerous nonpeptide ligands, we undertook a systematic mapping of GnRH-R residues involved in the binding of three nonpeptide antagonists. A region composed of the extracellular portions of transmembrane helices 6 and 7, extracellular loop 3, and the N-terminal domain significantly contributed to nonpeptide antagonist binding. However, each molecule was affected by a different subset of residues in these regions, indicating that each appears to occupy distinct, partially overlapping subregions within the more extensive peptide-binding pocket. Moreover, the resulting receptor interaction maps provide a basis to begin to reconcile structure-activity relationships between various nonpeptide and peptide series and facilitate the design of improved therapeutic agents.
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Affiliation(s)
- Stephen F Betz
- Department of Endocrinology, Neurocrine Biosciences, Inc., San Diego, California 92130, USA.
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von Haehling S, Doehner W, Anker SD. The roles of immunity and autoimmunity in chronic heart failure. ERNST SCHERING RESEARCH FOUNDATION WORKSHOP 2005:155-68. [PMID: 16329662 DOI: 10.1007/3-540-30822-9_10] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
Chronic heart failure (CHF) represents a major public health burden in developed countries. The introduction of new treatments has helped to improve its prognosis in recent years. However, it is still not possible to directly target the immunological aspects of the disease. In fact, chronic immune activation with the up-regulation of pro-inflammatory substances in the plasma remains an important feature of the disease, independently of its aetiology. Autoimmune mechanisms play a significant role in a subgroup of patients with dilated cardiomyopathy. The interplay between the two systems has not been established so far. This review briefly summarizes immune and autoimmune mechanisms in CHF.
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Affiliation(s)
- S von Haehling
- Department of Clinical Cardiology, Imperial College School of Medicine, National Heart & Lung Institute, London, UK.
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Brette F, Leroy J, Le Guennec JY, Sallé L. Ca2+ currents in cardiac myocytes: Old story, new insights. PROGRESS IN BIOPHYSICS AND MOLECULAR BIOLOGY 2005; 91:1-82. [PMID: 16503439 DOI: 10.1016/j.pbiomolbio.2005.01.001] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Calcium is a ubiquitous second messenger which plays key roles in numerous physiological functions. In cardiac myocytes, Ca2+ crosses the plasma membrane via specialized voltage-gated Ca2+ channels which have two main functions: (i) carrying depolarizing current by allowing positively charged Ca2+ ions to move into the cell; (ii) triggering Ca2+ release from the sarcoplasmic reticulum. Recently, it has been suggested than Ca2+ channels also participate in excitation-transcription coupling. The purpose of this review is to discuss the physiological roles of Ca2+ currents in cardiac myocytes. Next, we describe local regulation of Ca2+ channels by cyclic nucleotides. We also provide an overview of recent studies investigating the structure-function relationship of Ca2+ channels in cardiac myocytes using heterologous system expression and transgenic mice, with descriptions of the recently discovered Ca2+ channels alpha(1D) and alpha(1E). We finally discuss the potential involvement of Ca2+ currents in cardiac pathologies, such as diseases with autoimmune components, and cardiac remodeling.
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Affiliation(s)
- Fabien Brette
- School of Biomedical Sciences, University of Leeds, Worsley Building Leeds, LS2 9NQ, UK.
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Mobini R, Maschke H, Waagstein F. New insights into the pathogenesis of dilated cardiomyopathy: possible underlying autoimmune mechanisms and therapy. Autoimmun Rev 2004; 3:277-84. [PMID: 15246023 DOI: 10.1016/j.autrev.2003.10.005] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2003] [Revised: 10/13/2003] [Accepted: 10/13/2003] [Indexed: 01/22/2023]
Abstract
In the present study, autoimmune processes involved in the pathogenesis of dilated cardiomyopathy (DCM) are discussed. Genetic predisposition, persistent viral infection, and molecular mimicry have previously been described as the underlying mechanisms of the disease, and prevalence of autoantibodies (AABs) against several intra- and extracellular cardiotropic targets has been confirmed. These autoantibodies are able to disturb the normal physiological activity of the cardiomyocytes. They also could function as mediators in an activated immune system and direct a great deal of attention to injured tissue via (1) complement activation and (2) genesis of circulatory immunocomplexes (CICs) in association with self-antigens. The number as well as duration of accessible autoantigens or CICs seem to play an important role in activation of the antigen-presenting cells (APCs) and, consequently, promotion of autoimmunity. Since AABs play such a decisive role, their exclusion by immunoadsorption (IA) therapy has been discussed as a new approach in DCM treatment. Hitherto, all performed pilot studies using this approach have shown improvement in cardiac function and quality of life in the vast majority of treated DCM patients. The removal of circulating AABs may downregulate the autoimmune system, moderate the inflammatory signals, and hasten the recovery of the affected tissue.
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Affiliation(s)
- Reza Mobini
- Wallenberg Laboratory for Cardiovascular Research, Cardiovascular Institute, Göteborg University, Sahlgrenska University Hospital, 41345, Göteborg, Sweden
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