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Zeitlmayr S, Cami D, Selmani B, Gudermann T, Breit A. A dual role for ERK-1/2 in the regulation of plasmin activity and cell migration in metastatic NSCLC-H1299 cells. Arch Toxicol 2023; 97:3113-3128. [PMID: 37712947 PMCID: PMC10567951 DOI: 10.1007/s00204-023-03600-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2023] [Accepted: 08/30/2023] [Indexed: 09/16/2023]
Abstract
Occupational and environmental exposure of various toxins or cigarette smoke causes non-small cell lung carcinoma (NSCLC); a devastating disease with a very low survival rate after metastasis. Increased activity of plasmin is a hallmark in NSCLC metastasis. It is accepted that metastatic cells exhibit higher plasmin activity than cells from primary tumors. Mechanisms behind this elevation, however, are barely understood. We compared plasmin activity and cell migration of A549 cells derived from a primary lung tumor with metastatic H1299 lung cells isolated from lymph nodes. Surprisingly, we found higher plasmin activity and migration for A549 cells. mRNA levels of the plasminogen activator inhibitor-1 (PAI-1) were higher in H1299 cells and activity of extracellular-regulated kinases-1/2 (ERK-1/2) was increased. An inhibitor of ERK-1/2 decreased PAI-1 mRNA levels and increased plasmin activity or cell migration in H1299 cells. Transforming growth factor-β (TGF-β) decreased plasmin activity and migration in A549 cells but enhanced both in H1299 cells. The cytokine massively increased PAI-1 and decreased urokinase plasminogen activator (uPA) levels in A549 cells but strongly induced uPA and only weakly PAI- 1 expression in H1299 cells. Consequently, TGF-β enhanced plasmin activity and cell migration in H1299. Additionally, TGF-β activated ERK-1/2 stronger in H1299 than in A549 cells. Accordingly, an ERK-1/2 inhibitor completely reversed the effects of TGF-β on uPA expression, plasmin activity and migration in H1299 cells. Hence, we provide first data indicating TGF-β-promoted increased plasmin activity and suggest that blocking TGF-β-promoted ERK-1/2 activity might be a straightforward approach to inhibit NSCLC metastasis.
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Affiliation(s)
- Sarah Zeitlmayr
- Walther Straub Institute of Pharmacology and Toxicology, Medical Faculty, LMU Munich, Goethestrasse 33, 80336, Munich, Germany
| | - Ditila Cami
- Walther Straub Institute of Pharmacology and Toxicology, Medical Faculty, LMU Munich, Goethestrasse 33, 80336, Munich, Germany
| | - Belinda Selmani
- Walther Straub Institute of Pharmacology and Toxicology, Medical Faculty, LMU Munich, Goethestrasse 33, 80336, Munich, Germany
| | - Thomas Gudermann
- Walther Straub Institute of Pharmacology and Toxicology, Medical Faculty, LMU Munich, Goethestrasse 33, 80336, Munich, Germany
| | - Andreas Breit
- Walther Straub Institute of Pharmacology and Toxicology, Medical Faculty, LMU Munich, Goethestrasse 33, 80336, Munich, Germany.
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2
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Hoeger B, Nadolni W, Hampe S, Hoelting K, Fraticelli M, Zaborsky N, Madlmayr A, Sperrer V, Fraticelli L, Addington L, Steinritz D, Chubanov V, Geisberger R, Greil R, Breit A, Boekhoff I, Gudermann T, Zierler S. Inactivation of TRPM7 Kinase Targets AKT Signaling and Cyclooxygenase-2 Expression in Human CML Cells. Function (Oxf) 2023; 4:zqad053. [PMID: 37786778 PMCID: PMC10541797 DOI: 10.1093/function/zqad053] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2023] [Revised: 09/01/2023] [Accepted: 09/11/2023] [Indexed: 10/04/2023] Open
Abstract
Cyclooxygenase-2 (COX-2) is a key regulator of inflammation. High constitutive COX-2 expression enhances survival and proliferation of cancer cells, and adversely impacts antitumor immunity. The expression of COX-2 is modulated by various signaling pathways. Recently, we identified the melastatin-like transient-receptor-potential-7 (TRPM7) channel-kinase as modulator of immune homeostasis. TRPM7 protein is essential for leukocyte proliferation and differentiation, and upregulated in several cancers. It comprises of a cation channel and an atypical α-kinase, linked to inflammatory cell signals and associated with hallmarks of tumor progression. A role in leukemia has not been established, and signaling pathways are yet to be deciphered. We show that inhibiting TRPM7 channel-kinase in chronic myeloid leukemia (CML) cells results in reduced constitutive COX-2 expression. By utilizing a CML-derived cell line, HAP1, harboring CRISPR/Cas9-mediated TRPM7 knockout, or a point mutation inactivating TRPM7 kinase, we could link this to reduced activation of AKT serine/threonine kinase and mothers against decapentaplegic homolog 2 (SMAD2). We identified AKT as a direct in vitro substrate of TRPM7 kinase. Pharmacologic blockade of TRPM7 in wildtype HAP1 cells confirmed the effect on COX-2 via altered AKT signaling. Addition of an AKT activator on TRPM7 kinase-dead cells reconstituted the wildtype phenotype. Inhibition of TRPM7 resulted in reduced phosphorylation of AKT and diminished COX-2 expression in peripheral blood mononuclear cells derived from CML patients, and reduced proliferation in patient-derived CD34+ cells. These results highlight a role of TRPM7 kinase in AKT-driven COX-2 expression and suggest a beneficial potential of TRPM7 blockade in COX-2-related inflammation and malignancy.
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Affiliation(s)
- Birgit Hoeger
- Institute of Pharmacology, Johannes Kepler University Linz, Altenbergerstr. 69, 4040 Linz and Krankenhausstr. 5, 4020 Linz, Austria
| | - Wiebke Nadolni
- Walther Straub Institute of Pharmacology and Toxicology, Faculty of Medicine, Ludwig-Maximilians-Universität München, Goethestr. 33, 80336 Munich, Germany
| | - Sarah Hampe
- Walther Straub Institute of Pharmacology and Toxicology, Faculty of Medicine, Ludwig-Maximilians-Universität München, Goethestr. 33, 80336 Munich, Germany
| | - Kilian Hoelting
- Walther Straub Institute of Pharmacology and Toxicology, Faculty of Medicine, Ludwig-Maximilians-Universität München, Goethestr. 33, 80336 Munich, Germany
| | - Marco Fraticelli
- Walther Straub Institute of Pharmacology and Toxicology, Faculty of Medicine, Ludwig-Maximilians-Universität München, Goethestr. 33, 80336 Munich, Germany
| | - Nadja Zaborsky
- Department of Internal Medicine III with Haematology, Medical Oncology, Haemostaseology, Infectiology and Rheumatology, Oncologic Center, Paracelsus Medical University, 5020 Salzburg, Austria
- Salzburg Cancer Research Institute–Laboratory for Immunological and Molecular Cancer Research (SCRI–LIMCR), Müllner Hauptstr. 48, 5020 Salzburg, Austria
- Cancer Cluster Salzburg, 5020 Salzburg, Austria
| | - Anna Madlmayr
- Institute of Pharmacology, Johannes Kepler University Linz, Altenbergerstr. 69, 4040 Linz and Krankenhausstr. 5, 4020 Linz, Austria
| | - Viktoria Sperrer
- Institute of Pharmacology, Johannes Kepler University Linz, Altenbergerstr. 69, 4040 Linz and Krankenhausstr. 5, 4020 Linz, Austria
| | - Laura Fraticelli
- Walther Straub Institute of Pharmacology and Toxicology, Faculty of Medicine, Ludwig-Maximilians-Universität München, Goethestr. 33, 80336 Munich, Germany
| | - Lynda Addington
- Walther Straub Institute of Pharmacology and Toxicology, Faculty of Medicine, Ludwig-Maximilians-Universität München, Goethestr. 33, 80336 Munich, Germany
| | - Dirk Steinritz
- Walther Straub Institute of Pharmacology and Toxicology, Faculty of Medicine, Ludwig-Maximilians-Universität München, Goethestr. 33, 80336 Munich, Germany
| | - Vladimir Chubanov
- Walther Straub Institute of Pharmacology and Toxicology, Faculty of Medicine, Ludwig-Maximilians-Universität München, Goethestr. 33, 80336 Munich, Germany
| | - Roland Geisberger
- Department of Internal Medicine III with Haematology, Medical Oncology, Haemostaseology, Infectiology and Rheumatology, Oncologic Center, Paracelsus Medical University, 5020 Salzburg, Austria
- Salzburg Cancer Research Institute–Laboratory for Immunological and Molecular Cancer Research (SCRI–LIMCR), Müllner Hauptstr. 48, 5020 Salzburg, Austria
- Cancer Cluster Salzburg, 5020 Salzburg, Austria
| | - Richard Greil
- Department of Internal Medicine III with Haematology, Medical Oncology, Haemostaseology, Infectiology and Rheumatology, Oncologic Center, Paracelsus Medical University, 5020 Salzburg, Austria
- Salzburg Cancer Research Institute–Laboratory for Immunological and Molecular Cancer Research (SCRI–LIMCR), Müllner Hauptstr. 48, 5020 Salzburg, Austria
- Cancer Cluster Salzburg, 5020 Salzburg, Austria
| | - Andreas Breit
- Walther Straub Institute of Pharmacology and Toxicology, Faculty of Medicine, Ludwig-Maximilians-Universität München, Goethestr. 33, 80336 Munich, Germany
| | - Ingrid Boekhoff
- Walther Straub Institute of Pharmacology and Toxicology, Faculty of Medicine, Ludwig-Maximilians-Universität München, Goethestr. 33, 80336 Munich, Germany
| | - Thomas Gudermann
- Walther Straub Institute of Pharmacology and Toxicology, Faculty of Medicine, Ludwig-Maximilians-Universität München, Goethestr. 33, 80336 Munich, Germany
| | - Susanna Zierler
- Institute of Pharmacology, Johannes Kepler University Linz, Altenbergerstr. 69, 4040 Linz and Krankenhausstr. 5, 4020 Linz, Austria
- Walther Straub Institute of Pharmacology and Toxicology, Faculty of Medicine, Ludwig-Maximilians-Universität München, Goethestr. 33, 80336 Munich, Germany
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3
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Khajavi N, Riçku K, Schreier PCF, Gentz T, Beyerle P, Cruz E, Breit A, Reinach PS, Gudermann T. Chronic Mg 2+ Deficiency Does Not Impair Insulin Secretion in Mice. Cells 2023; 12:1790. [PMID: 37443824 PMCID: PMC10340716 DOI: 10.3390/cells12131790] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2023] [Revised: 06/28/2023] [Accepted: 07/03/2023] [Indexed: 07/15/2023] Open
Abstract
Magnesium is an essential mediator of a vast number of critical enzymatic cellular reactions in the human body. Some clinical epidemiological studies suggest that hypomagnesemia accounts for declines in insulin secretion in patients with type 2 diabetes (T2D); however, the results of various experimental studies do not support this notion. To address this discrepancy, we assessed the short- and long-term effects of hypomagnesemia on β-cell function and insulin secretion in primary mouse islets of Langerhans and in a mouse model of hypomagnesemia known as Trpm6Δ17 /fl;Villin1-Cre mice. We found that lowering the extracellular Mg2+ concentration from 1.2 mM to either 0.6 or 0.1 mM remarkably increased glucose-induced insulin secretion (GIIS) in primary islets isolated from C57BL/6 mice. Similarly, both the plasma insulin levels and GIIS rose in isolated islets of Trpm6Δ17 /fl;Villin1-Cre mice. We attribute these rises to augmented increases in intracellular Ca2+ oscillations in pancreatic β-cells. However, the glycemic metabolic profile was not impaired in Trpm6Δ17 /fl;Villin1-Cre mice, suggesting that chronic hypomagnesemia does not lead to insulin resistance. Collectively, the results of this study suggest that neither acute nor chronic Mg2+ deficiency suppresses glucose-induced rises in insulin secretion. Even though hypomagnesemia can be symptomatic of T2D, such deficiency may not account for declines in insulin release in this disease.
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Affiliation(s)
- Noushafarin Khajavi
- Walther Straub Institute of Pharmacology and Toxicology, LMU Munich, 80539 Munich, Germany; (K.R.); (P.C.F.S.); (T.G.); (P.B.); (E.C.); (A.B.)
| | - Klea Riçku
- Walther Straub Institute of Pharmacology and Toxicology, LMU Munich, 80539 Munich, Germany; (K.R.); (P.C.F.S.); (T.G.); (P.B.); (E.C.); (A.B.)
| | - Pascale C. F. Schreier
- Walther Straub Institute of Pharmacology and Toxicology, LMU Munich, 80539 Munich, Germany; (K.R.); (P.C.F.S.); (T.G.); (P.B.); (E.C.); (A.B.)
| | - Tanja Gentz
- Walther Straub Institute of Pharmacology and Toxicology, LMU Munich, 80539 Munich, Germany; (K.R.); (P.C.F.S.); (T.G.); (P.B.); (E.C.); (A.B.)
| | - Philipp Beyerle
- Walther Straub Institute of Pharmacology and Toxicology, LMU Munich, 80539 Munich, Germany; (K.R.); (P.C.F.S.); (T.G.); (P.B.); (E.C.); (A.B.)
| | - Emmanuel Cruz
- Walther Straub Institute of Pharmacology and Toxicology, LMU Munich, 80539 Munich, Germany; (K.R.); (P.C.F.S.); (T.G.); (P.B.); (E.C.); (A.B.)
| | - Andreas Breit
- Walther Straub Institute of Pharmacology and Toxicology, LMU Munich, 80539 Munich, Germany; (K.R.); (P.C.F.S.); (T.G.); (P.B.); (E.C.); (A.B.)
| | - Peter S. Reinach
- Ophthalmology Department, Wenzhou Medical University, Wenzhou 325015, China;
| | - Thomas Gudermann
- Walther Straub Institute of Pharmacology and Toxicology, LMU Munich, 80539 Munich, Germany; (K.R.); (P.C.F.S.); (T.G.); (P.B.); (E.C.); (A.B.)
- German Center for Lung Research, 81377 Munich, Germany
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4
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Geiger F, Zeitlmayr S, Staab-Weijnitz CA, Rajan S, Breit A, Gudermann T, Dietrich A. An Inhibitory Function of TRPA1 Channels in TGF-β1-driven Fibroblast-to-Myofibroblast Differentiation. Am J Respir Cell Mol Biol 2023; 68:314-325. [PMID: 36378826 DOI: 10.1165/rcmb.2022-0159oc] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
TRPA1 (transient receptor potential ankyrin 1) is a nonselective Ca2+-permeable cation channel, which was originally cloned from human lung fibroblasts (HLFs). TRPA1-mediated Ca2+ entry is evoked by exposure to several chemicals, including allyl isothiocyanate (AITC), and a protective effect of TRPA1 activation in the development of cardiac fibrosis has been proposed. Yet the function of TRPA1 in TGF-β1 (transforming growth factor-β1)-driven fibroblast-to-myofibroblast differentiation and the development of pulmonary fibrosis remains elusive. TRPA1 expression and function were analyzed in cultured primary HLFs, and mRNA concentrations were significantly reduced after adding TGF-β1. Expression of genes encoding fibrosis markers (e.g., ACTA2, SERPINE1 [plasminogen activator inhibitor 1], FN1 [fibronectin], COL1A1 [type I collagen]) was increased after siRNA-mediated downregulation of TRPA1 mRNA in HLFs. Moreover, AITC-induced Ca2+ entry in HLFs was decreased after TGF-β1 treatment and by application of TRPA1 siRNAs, while AITC treatment alone did not reduce cell viability or enhance apoptosis. Most interestingly, AITC-induced TRPA1 activation augmented ERK1/2 (extracellular signal-regulated kinase 1/2) and SMAD2 linker phosphorylation, which might inhibit TGF-β-receptor signaling. Our results suggest an inhibitory function of TRPA1 channels in TGF-β1-driven fibroblast-to-myofibroblast differentiation. Therefore, activation of TRPA1 channels might be protective during the development of pulmonary fibrosis in patients.
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Affiliation(s)
- Fabienne Geiger
- Walther Straub Institute of Pharmacology and Toxicology, Member of the German Center for Lung Research, Ludwig-Maximilians-University Munich, Munich, Germany, and
| | - Sarah Zeitlmayr
- Walther Straub Institute of Pharmacology and Toxicology, Member of the German Center for Lung Research, Ludwig-Maximilians-University Munich, Munich, Germany, and
| | - Claudia A Staab-Weijnitz
- Comprehensive Pneumology Center with the CPC-M BioArchive and Institute of Lung Health and Immunity, Helmholtz Center Munich, Member of the German Center for Lung Research, Munich, Germany
| | - Suhasini Rajan
- Walther Straub Institute of Pharmacology and Toxicology, Member of the German Center for Lung Research, Ludwig-Maximilians-University Munich, Munich, Germany, and
| | - Andreas Breit
- Walther Straub Institute of Pharmacology and Toxicology, Member of the German Center for Lung Research, Ludwig-Maximilians-University Munich, Munich, Germany, and
| | - Thomas Gudermann
- Walther Straub Institute of Pharmacology and Toxicology, Member of the German Center for Lung Research, Ludwig-Maximilians-University Munich, Munich, Germany, and
| | - Alexander Dietrich
- Walther Straub Institute of Pharmacology and Toxicology, Member of the German Center for Lung Research, Ludwig-Maximilians-University Munich, Munich, Germany, and
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5
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Khajavi N, Beck A, Riçku K, Beyerle P, Jacob K, Syamsul SF, Belkacemi A, Reinach PS, Schreier PC, Salah H, Popp T, Novikoff A, Breit A, Chubanov V, Müller TD, Zierler S, Gudermann T. TRPM7 kinase is required for insulin production and compensatory islet responses during obesity. JCI Insight 2023; 8:163397. [PMID: 36574297 PMCID: PMC9977431 DOI: 10.1172/jci.insight.163397] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2022] [Accepted: 12/21/2022] [Indexed: 12/28/2022] Open
Abstract
Most overweight individuals do not develop diabetes due to compensatory islet responses to restore glucose homeostasis. Therefore, regulatory pathways that promote β cell compensation are potential targets for treatment of diabetes. The transient receptor potential cation channel subfamily M member 7 protein (TRPM7), harboring a cation channel and a serine/threonine kinase, has been implicated in controlling cell growth and proliferation. Here, we report that selective deletion of Trpm7 in β cells disrupted insulin secretion and led to progressive glucose intolerance. We indicate that the diminished insulinotropic response in β cell-specific Trpm7-knockout mice was caused by decreased insulin production because of impaired enzymatic activity of this protein. Accordingly, high-fat-fed mice with a genetic loss of TRPM7 kinase activity displayed a marked glucose intolerance accompanied by hyperglycemia. These detrimental glucoregulatory effects were engendered by reduced compensatory β cell responses because of mitigated protein kinase B (AKT)/ERK signaling. Collectively, our data identify TRPM7 kinase as a potentially novel regulator of insulin synthesis, β cell dynamics, and glucose homeostasis under obesogenic diet.
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Affiliation(s)
- Noushafarin Khajavi
- Walther Straub Institute of Pharmacology and Toxicology, LMU Munich, Munich, Germany
| | - Andreas Beck
- Institute of Experimental and Clinical Pharmacology and Toxicology, Saarland University, Homburg, Germany
| | - Klea Riçku
- Walther Straub Institute of Pharmacology and Toxicology, LMU Munich, Munich, Germany
| | - Philipp Beyerle
- Walther Straub Institute of Pharmacology and Toxicology, LMU Munich, Munich, Germany
| | - Katharina Jacob
- Walther Straub Institute of Pharmacology and Toxicology, LMU Munich, Munich, Germany
| | - Sabrina F. Syamsul
- Walther Straub Institute of Pharmacology and Toxicology, LMU Munich, Munich, Germany
| | - Anouar Belkacemi
- Institute of Experimental and Clinical Pharmacology and Toxicology, Saarland University, Homburg, Germany
| | - Peter S. Reinach
- Wenzhou Medical University, Ophthalmology Department, Wenzhou, China
| | - Pascale C.F. Schreier
- Walther Straub Institute of Pharmacology and Toxicology, LMU Munich, Munich, Germany
| | - Houssein Salah
- Institute of Experimental and Clinical Pharmacology and Toxicology, Saarland University, Homburg, Germany
| | - Tanja Popp
- Bundeswehr Institute of Radiobiology, Munich, Germany
| | - Aaron Novikoff
- Institute of Diabetes and Obesity, Helmholtz Center Munich, Neuherberg, Germany.,German Center for Diabetes Research (DZD), Neuherberg, Germany
| | - Andreas Breit
- Walther Straub Institute of Pharmacology and Toxicology, LMU Munich, Munich, Germany
| | - Vladimir Chubanov
- Walther Straub Institute of Pharmacology and Toxicology, LMU Munich, Munich, Germany
| | - Timo D. Müller
- Institute of Diabetes and Obesity, Helmholtz Center Munich, Neuherberg, Germany.,German Center for Diabetes Research (DZD), Neuherberg, Germany
| | - Susanna Zierler
- Walther Straub Institute of Pharmacology and Toxicology, LMU Munich, Munich, Germany.,Institute of Pharmacology, Medical Faculty, Johannes Kepler University Linz, Linz, Austria
| | - Thomas Gudermann
- Walther Straub Institute of Pharmacology and Toxicology, LMU Munich, Munich, Germany.,German Center for Lung Research, Munich, Germany
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6
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Zeitlmayr S, Zierler S, Staab-Weijnitz CA, Dietrich A, Geiger F, Horgen FD, Gudermann T, Breit A. TRPM7 restrains plasmin activity and promotes transforming growth factor-β1 signaling in primary human lung fibroblasts. Arch Toxicol 2022; 96:2767-2783. [PMID: 35864199 PMCID: PMC9302958 DOI: 10.1007/s00204-022-03342-x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2022] [Accepted: 07/14/2022] [Indexed: 02/07/2023]
Abstract
Sustained exposure of the lung to various environmental or occupational toxins may eventually lead to pulmonary fibrosis, a devastating disease with no cure. Pulmonary fibrosis is characterized by excessive deposition of extracellular matrix (ECM) proteins such as fibronectin and collagens. The peptidase plasmin degrades the ECM, but protein levels of the plasmin activator inhibitor-1 (PAI-1) are increased in fibrotic lung tissue, thereby dampening plasmin activity. Transforming growth factor-β1 (TGF-β1)-induced activation of SMAD transcription factors promotes ECM deposition by enhancing collagen, fibronectin and PAI-1 levels in pulmonary fibroblasts. Hence, counteracting TGF-β1-induced signaling is a promising approach for the therapy of pulmonary fibrosis. Transient receptor potential cation channel subfamily M Member 7 (TRPM7) supports TGF-β1-promoted SMAD signaling in T-lymphocytes and the progression of fibrosis in kidney and heart. Thus, we investigated possible effects of TRPM7 on plasmin activity, ECM levels and TGF-β1 signaling in primary human pulmonary fibroblasts (pHPF). We found that two structurally unrelated TRPM7 blockers enhanced plasmin activity and reduced fibronectin or PAI-1 protein levels in pHPF under basal conditions. Further, TRPM7 blockade strongly inhibited fibronectin and collagen deposition induced by sustained TGF-β1 stimulation. In line with these data, inhibition of TRPM7 activity diminished TGF-β1-triggered phosphorylation of SMAD-2, SMAD-3/4-dependent reporter activation and PAI-1 mRNA levels. Overall, we uncover TRPM7 as a novel supporter of TGF-β1 signaling in pHPF and propose TRPM7 blockers as new candidates to control excessive ECM levels under pathophysiological conditions conducive to pulmonary fibrosis.
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Affiliation(s)
- Sarah Zeitlmayr
- Walther Straub Institute of Pharmacology and Toxicology, Medical Faculty, LMU Munich, Goethestrasse 33, 80336, Munich, Germany
| | - Susanna Zierler
- Walther Straub Institute of Pharmacology and Toxicology, Medical Faculty, LMU Munich, Goethestrasse 33, 80336, Munich, Germany.,Faculty of Medicine, Johannes Kepler University, Life Science Park, Huemerstraße 3-5, 4020, Linz, Austria
| | - Claudia A Staab-Weijnitz
- Institute of Lung Health and Immunity and Comprehensive Pneumology Center, Helmholtz Zentrum München GmbH, Member of the German Center for Lung Research, Max-Lebsche-Platz 31, 81377, Munich, Germany
| | - Alexander Dietrich
- Walther Straub Institute of Pharmacology and Toxicology, Medical Faculty, LMU Munich, Goethestrasse 33, 80336, Munich, Germany
| | - Fabienne Geiger
- Walther Straub Institute of Pharmacology and Toxicology, Medical Faculty, LMU Munich, Goethestrasse 33, 80336, Munich, Germany
| | - F David Horgen
- Department of Natural Sciences, Hawaii Pacific University, Kaneohe, HI, 96744, USA
| | - Thomas Gudermann
- Walther Straub Institute of Pharmacology and Toxicology, Medical Faculty, LMU Munich, Goethestrasse 33, 80336, Munich, Germany
| | - Andreas Breit
- Walther Straub Institute of Pharmacology and Toxicology, Medical Faculty, LMU Munich, Goethestrasse 33, 80336, Munich, Germany.
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7
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Faro D, Boekhoff I, Gudermann T, Breit A. Physiological Temperature Changes Fine-Tune β 2- Adrenergic Receptor-Induced Cytosolic cAMP Accumulation. Mol Pharmacol 2021; 100:203-216. [PMID: 34158361 DOI: 10.1124/molpharm.121.000309] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2021] [Accepted: 06/04/2021] [Indexed: 11/22/2022] Open
Abstract
Norepinephrine (NE) controls many vital body functions by activating adrenergic receptors (ARs). Average core body temperature (CBT) in mice is 37°C. Of note, CBT fluctuates between 36 and 38°C within 24 hours, but little is known about the effects of CBT changes on the pharmacodynamics of NE. Here, we used Peltier element-controlled incubators and challenged murine hypothalamic mHypoA -2/10 cells with temperature changes of ±1°C. We observed enhanced NE-induced activation of a cAMP-dependent luciferase reporter at 36 compared with 38°C. mRNA analysis and subtype specific antagonists revealed that NE activates β 2- and β 3-AR in mHypoA-2/10 cells. Agonist binding to the β 2-AR was temperature insensitive, but measurements of cytosolic cAMP accumulation revealed an increase in efficacy of 45% ± 27% for NE and of 62% ± 33% for the β 2-AR-selective agonist salmeterol at 36°C. When monitoring NE-promoted cAMP efflux, we observed an increase in the absolute efflux at 36°C. However, the ratio of exported to cytosolic accumulated cAMP is higher at 38°C. We also stimulated cells with NE at 37°C and measured cAMP degradation at 36 and 38°C afterward. We observed increased cAMP degradation at 38°C, indicating enhanced phosphodiesterase activity at higher temperatures. In line with these data, NE-induced activation of the thyreoliberin promoter was found to be enhanced at 36°C. Overall, we show that physiologic temperature changes fine-tune NE-induced cAMP signaling in hypothalamic cells via β 2-AR by modulating cAMP degradation and the ratio of intra- and extracellular cAMP. SIGNIFICANCE STATEMENT: Increasing cytosolic cAMP levels by activation of G protein-coupled receptors (GPCR) such as the β 2-adrenergic receptor (AR) is essential for many body functions. Changes in core body temperature are fundamental and universal factors of mammalian life. This study provides the first data linking physiologically relevant temperature fluctuations to β 2-AR-induced cAMP signaling, highlighting a so far unappreciated role of body temperature as a modulator of the prototypic class A GPCR.
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MESH Headings
- 1-Methyl-3-isobutylxanthine/pharmacology
- ARNTL Transcription Factors/metabolism
- Aminopyridines/pharmacology
- Animals
- Cell Line
- Cyclic AMP/metabolism
- Cyclic AMP Response Element-Binding Protein/metabolism
- Cytosol/metabolism
- Forkhead Transcription Factors/metabolism
- GTP-Binding Protein alpha Subunits, Gq-G11/physiology
- GTP-Binding Protein alpha Subunits, Gs/physiology
- Hypothalamus/physiology
- Mice
- Neurons/physiology
- Norepinephrine/pharmacology
- Receptors, Adrenergic, beta-2/biosynthesis
- Receptors, Adrenergic, beta-2/physiology
- Receptors, Adrenergic, beta-3/biosynthesis
- Receptors, Adrenergic, beta-3/physiology
- STAT Transcription Factors/metabolism
- Salmeterol Xinafoate/pharmacology
- Signal Transduction/physiology
- Temperature
- Thyrotropin-Releasing Hormone/genetics
- Thyrotropin-Releasing Hormone/metabolism
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Affiliation(s)
- Dennis Faro
- Walther-Straub-Institut für Pharmakologie und Toxikologie, Ludwig-Maximilians-Universität München, München, Germany
| | - Ingrid Boekhoff
- Walther-Straub-Institut für Pharmakologie und Toxikologie, Ludwig-Maximilians-Universität München, München, Germany
| | - Thomas Gudermann
- Walther-Straub-Institut für Pharmakologie und Toxikologie, Ludwig-Maximilians-Universität München, München, Germany
| | - Andreas Breit
- Walther-Straub-Institut für Pharmakologie und Toxikologie, Ludwig-Maximilians-Universität München, München, Germany
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Arlt E, Fraticelli M, Tsvilovskyy V, Nadolni W, Breit A, O'Neill TJ, Resenberger S, Wennemuth G, Wahl-Schott C, Biel M, Grimm C, Freichel M, Gudermann T, Klugbauer N, Boekhoff I, Zierler S. TPC1 deficiency or blockade augments systemic anaphylaxis and mast cell activity. Proc Natl Acad Sci U S A 2020; 117:18068-18078. [PMID: 32661165 PMCID: PMC7395440 DOI: 10.1073/pnas.1920122117] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Mast cells and basophils are main drivers of allergic reactions and anaphylaxis, for which prevalence is rapidly increasing. Activation of these cells leads to a tightly controlled release of inflammatory mediators stored in secretory granules. The release of these granules is dependent on intracellular calcium (Ca2+) signals. Ca2+ release from endolysosomal compartments is mediated via intracellular cation channels, such as two-pore channel (TPC) proteins. Here, we uncover a mechanism for how TPC1 regulates Ca2+ homeostasis and exocytosis in mast cells in vivo and ex vivo. Notably, in vivo TPC1 deficiency in mice leads to enhanced passive systemic anaphylaxis, reflected by increased drop in body temperature, most likely due to accelerated histamine-induced vasodilation. Ex vivo, mast cell-mediated histamine release and degranulation was augmented upon TPC1 inhibition, although mast cell numbers and size were diminished. Our results indicate an essential role of TPC1 in endolysosomal Ca2+ uptake and filling of endoplasmic reticulum Ca2+ stores, thereby regulating exocytosis in mast cells. Thus, pharmacological modulation of TPC1 might blaze a trail to develop new drugs against mast cell-related diseases, including allergic hypersensitivity.
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Affiliation(s)
- Elisabeth Arlt
- Walther Straub Institute of Pharmacology and Toxicology, Ludwig-Maximilians-Universität München, 80336 München, Germany
| | - Marco Fraticelli
- Walther Straub Institute of Pharmacology and Toxicology, Ludwig-Maximilians-Universität München, 80336 München, Germany
| | | | - Wiebke Nadolni
- Walther Straub Institute of Pharmacology and Toxicology, Ludwig-Maximilians-Universität München, 80336 München, Germany
| | - Andreas Breit
- Walther Straub Institute of Pharmacology and Toxicology, Ludwig-Maximilians-Universität München, 80336 München, Germany
| | - Thomas J O'Neill
- Walther Straub Institute of Pharmacology and Toxicology, Ludwig-Maximilians-Universität München, 80336 München, Germany
| | - Stefanie Resenberger
- Walther Straub Institute of Pharmacology and Toxicology, Ludwig-Maximilians-Universität München, 80336 München, Germany
| | - Gunther Wennemuth
- Institute for Anatomy, University of Duisburg-Essen, 45147 Duisburg, Germany
| | | | - Martin Biel
- Department of Pharmacy, Ludwig-Maximilians-Universität München, 81377 München, Germany
| | - Christian Grimm
- Walther Straub Institute of Pharmacology and Toxicology, Ludwig-Maximilians-Universität München, 80336 München, Germany
| | - Marc Freichel
- Institute of Pharmacology, University of Heidelberg, 69120 Heidelberg, Germany
| | - Thomas Gudermann
- Walther Straub Institute of Pharmacology and Toxicology, Ludwig-Maximilians-Universität München, 80336 München, Germany
| | - Norbert Klugbauer
- Institute for Experimental and Clinical Pharmacology and Toxicology, Medical Faculty, Albert-Ludwigs-Universität, 79104 Freiburg, Germany
| | - Ingrid Boekhoff
- Walther Straub Institute of Pharmacology and Toxicology, Ludwig-Maximilians-Universität München, 80336 München, Germany;
| | - Susanna Zierler
- Walther Straub Institute of Pharmacology and Toxicology, Ludwig-Maximilians-Universität München, 80336 München, Germany;
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9
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Tsoutsoulopoulos A, Gohlsch K, Möhle N, Breit A, Hoffmann S, Krischenowski O, Mückter H, Gudermann T, Thiermann H, Aufderheide M, Steinritz D. Assessment of the Acute Inhalation Toxicity of Airborne Particles by Exposing Cultivated Human Lung Cells at the Air-Liquid Interface. J Vis Exp 2020. [PMID: 32150152 DOI: 10.3791/60572] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022] Open
Abstract
Here, we present a specially designed modular in vitro exposure system that enables the homogenous exposure of cultivated human lung cells at the ALI to gases, particles or complex atmospheres (e.g., cigarette smoke), thus providing realistic physiological exposure of the apical surface of the human alveolar region to air. In contrast to sequential exposure models with linear aerosol guidance, the modular design of the radial flow system meets all requirements for the continuous generation and transport of the test atmosphere to the cells, a homogenous distribution and deposition of the particles and the continuous removal of the atmosphere. This exposure method is primarily designed for the exposure of cells to airborne particles, but can be adapted to the exposure of liquid aerosols and highly toxic and aggressive gases depending on the aerosol generation method and the material of the exposure modules. Within the framework of a recently completed validation study, this exposure system was proven as a transferable, reproducible and predictive screening method for the qualitative assessment of the acute pulmonary cytotoxicity of airborne particles, thereby potentially reducing or replacing animal experiments that would normally provide this toxicological assessment.
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Affiliation(s)
| | - Katrin Gohlsch
- Walther Straub Institute of Pharmacology and Toxicology, University of Munich
| | | | - Andreas Breit
- Walther Straub Institute of Pharmacology and Toxicology, University of Munich
| | | | - Olaf Krischenowski
- Cultex Laboratories GmbH; Cultex Technologies GmbH (formerly Cultex Laboratories GmbH)
| | - Harald Mückter
- Walther Straub Institute of Pharmacology and Toxicology, University of Munich
| | - Thomas Gudermann
- Walther Straub Institute of Pharmacology and Toxicology, University of Munich
| | | | - Michaela Aufderheide
- Cultex Laboratories GmbH; Cultex Technologies GmbH (formerly Cultex Laboratories GmbH)
| | - Dirk Steinritz
- Bundeswehr Institute of Pharmacology and Toxicology; Walther Straub Institute of Pharmacology and Toxicology, University of Munich
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10
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Gohlsch K, Mückter H, Steinritz D, Aufderheide M, Hoffmann S, Gudermann T, Breit A. Exposure of 19 substances to lung A549 cells at the air liquid interface or under submerged conditions reveals high correlation between cytotoxicity in vitro and CLP classifications for acute lung toxicity. Toxicol Lett 2019; 316:119-126. [DOI: 10.1016/j.toxlet.2019.09.014] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2019] [Revised: 08/23/2019] [Accepted: 09/14/2019] [Indexed: 02/07/2023]
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11
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Tsoutsoulopoulos A, Gohlsch K, Möhle N, Breit A, Hoffmann S, Krischenowski O, Mückter H, Gudermann T, Thiermann H, Aufderheide M, Steinritz D. Validation of the CULTEX® Radial Flow System for the assessment of the acute inhalation toxicity of airborne particles. Toxicol In Vitro 2019; 58:245-255. [PMID: 30890356 DOI: 10.1016/j.tiv.2019.03.020] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2018] [Revised: 03/08/2019] [Accepted: 03/15/2019] [Indexed: 12/14/2022]
Abstract
The CULTEX® Radial Flow System (RFS) is a modular in vitro system for the homogenous exposure of cells to airborne particles at the air-liquid interface (ALI). A former pre-validation study successfully demonstrated the general applicability of the CULTEX® RFS and its transferability, stability and reproducibility. Based on these results, the methodology was optimized, validated and prediction models for acute inhalation hazards were established. Cell viability of A549 cells after ALI exposure to 20 pre-selected test substances was assessed in three independent laboratories. Cytotoxicity of test substances was compared to the respective incubator controls and used as an indicator of toxicity. Substances were considered to exert an acute inhalation hazard when viability decreased below 50% (prediction model (PM) 50%) or 75% (PM 75%) at any of three exposure doses (25, 50 or 100 μg/cm2). Results were then compared to existing in vivo data and revealed an overall concordance of 85%, with a specificity of 83% and a sensitivity of 88%. Depending on the applied PM, the within-laboratory and between-laboratory reproducibility ranged from 90 to 100%. In summary, the CULTEX® RFS was proven as a transferable, reproducible and well predictive screening method for the qualitative assessment of the acute pulmonary cytotoxicity of airborne particles.
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Affiliation(s)
| | - Katrin Gohlsch
- Walther-Straub-Institute of Pharmacology and Toxicology, Ludwig-Maximilians-Universität, Munich, Germany
| | | | - Andreas Breit
- Walther-Straub-Institute of Pharmacology and Toxicology, Ludwig-Maximilians-Universität, Munich, Germany
| | | | - Olaf Krischenowski
- Cultex® Laboratories GmbH, Hannover, Germany; Cultex® Technology GmbH (formerly Cultex® Laboratories GmbH), Hannover, Germany
| | - Harald Mückter
- Walther-Straub-Institute of Pharmacology and Toxicology, Ludwig-Maximilians-Universität, Munich, Germany
| | - Thomas Gudermann
- Walther-Straub-Institute of Pharmacology and Toxicology, Ludwig-Maximilians-Universität, Munich, Germany
| | - Horst Thiermann
- Bundeswehr Institute of Pharmacology and Toxicology, Munich, Germany
| | - Michaela Aufderheide
- Cultex® Laboratories GmbH, Hannover, Germany; Cultex® Technology GmbH (formerly Cultex® Laboratories GmbH), Hannover, Germany
| | - Dirk Steinritz
- Bundeswehr Institute of Pharmacology and Toxicology, Munich, Germany; Walther-Straub-Institute of Pharmacology and Toxicology, Ludwig-Maximilians-Universität, Munich, Germany
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12
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Breit A, Miek L, Schredelseker J, Geibel M, Merrow M, Gudermann T. Insulin-like growth factor-1 acts as a zeitgeber on hypothalamic circadian clock gene expression via glycogen synthase kinase-3β signaling. J Biol Chem 2018; 293:17278-17290. [PMID: 30217816 DOI: 10.1074/jbc.ra118.004429] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2018] [Revised: 08/22/2018] [Indexed: 12/12/2022] Open
Abstract
Brain and muscle ARNT-like protein-1 (BMAL-1) is an important component of the cellular circadian clock. Proteins such as epidermal (EGF) or nerve growth factor (NGF) affect the cellular clock via extracellular signal-regulated kinases-1/2 (ERK-1/2) in NIH3T3 or neuronal stem cells, but no such data are available for the insulin-like growth factor-1 (IGF-1). The hypothalamus expresses receptors for all three growth factors, acts as a central circadian pacemaker, and releases hormones in a circadian fashion. However, little is known about growth factor-induced modulation of clock gene activity in hypothalamic cells. Here, we investigated effects of IGF-1, EGF, or NGF on the Bmal-1 promoter in two hypothalamic cell lines. We found that only IGF-1 but not EGF or NGF enhanced activity of the Bmal-1 promoter. Inhibition of ERK-1/2 activity did not affect IGF-1-induced Bmal-1 promoter activation and all three growth factors similarly phosphorylated ERK-1/2, questioning a role for ERK-1/2 in controlling BMAL-1 promoter activity. Of note, only IGF-1 induced sustained phosphorylation of glycogen synthase kinase-3β (GSK-3β). Moreover, the GSK-3β inhibitor lithium or siRNA-mediated GSK-3β knockdown diminished the effects of IGF-1 on the Bmal-1 promoter. When IGF-1 was used in the context of temperature cycles entraining hypothalamic clock gene expression to a 24-h rhythm, it shifted the phase of Bmal-1 promoter activity, indicating that IGF-1 functions as a zeitgeber for cellular hypothalamic circadian clocks. Our results reveal that IGF-1 regulates clock gene expression and that GSK-3β but not ERK-1/2 is required for the IGF-1-mediated regulation of the Bmal-1 promoter in hypothalamic cells.
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Affiliation(s)
- Andreas Breit
- From the Walther Straub Institute of Pharmacology and Toxicology, Medical Faculty, LMU Munich, Goethestrasse 33, 80336 Munich and
| | - Laura Miek
- From the Walther Straub Institute of Pharmacology and Toxicology, Medical Faculty, LMU Munich, Goethestrasse 33, 80336 Munich and
| | - Johann Schredelseker
- From the Walther Straub Institute of Pharmacology and Toxicology, Medical Faculty, LMU Munich, Goethestrasse 33, 80336 Munich and
| | - Mirjam Geibel
- the Institute of Medical Psychology, Medical Faculty, LMU Munich, Goethestrasse 31, 80336 Munich, Germany
| | - Martha Merrow
- the Institute of Medical Psychology, Medical Faculty, LMU Munich, Goethestrasse 31, 80336 Munich, Germany
| | - Thomas Gudermann
- From the Walther Straub Institute of Pharmacology and Toxicology, Medical Faculty, LMU Munich, Goethestrasse 33, 80336 Munich and
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13
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Schweitzer MK, Wilting F, Sedej S, Dreizehnter L, Dupper NJ, Tian Q, Moretti A, My I, Kwon O, Priori SG, Laugwitz KL, Storch U, Lipp P, Breit A, Mederos y Schnitzler M, Gudermann T, Schredelseker J. Suppression of Arrhythmia by Enhancing Mitochondrial Ca 2+ Uptake in Catecholaminergic Ventricular Tachycardia Models. JACC Basic Transl Sci 2017; 2:737-747. [PMID: 29354781 PMCID: PMC5774336 DOI: 10.1016/j.jacbts.2017.06.008] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/10/2017] [Revised: 06/26/2017] [Accepted: 06/27/2017] [Indexed: 11/30/2022]
Abstract
Cardiovascular disease-related deaths frequently arise from arrhythmias, but treatment options are limited due to perilous side effects of commonly used antiarrhythmic drugs. Cardiac rhythmicity strongly depends on cardiomyocyte Ca2+ handling and prevalent cardiac diseases are causally associated with perturbations in intracellular Ca2+ handling. Therefore, intracellular Ca2+ transporters are lead candidate structures for novel and safer antiarrhythmic therapies. Mitochondria and mitochondrial Ca2+ transport proteins are important regulators of cardiac Ca2+ handling. Here we evaluated the potential of pharmacological activation of mitochondrial Ca2+ uptake for the treatment of cardiac arrhythmia. To this aim,we tested substances that enhance mitochondrial Ca2+ uptake for their ability to suppress arrhythmia in a murine model for ryanodine receptor 2 (RyR2)-mediated catecholaminergic polymorphic ventricular tachycardia (CPVT) in vitro and in vivo and in induced pluripotent stem cell-derived cardiomyocytes from a CPVT patient. In freshly isolated cardiomyocytes of RyR2R4496C/WT mice efsevin, a synthetic agonist of the voltage-dependent anion channel 2 (VDAC2) in the outer mitochondrial membrane, prevented the formation of diastolic Ca2+ waves and spontaneous action potentials. The antiarrhythmic effect of efsevin was abolished by blockade of the mitochondrial Ca2+ uniporter (MCU), but could be reproduced using the natural MCU activator kaempferol. Both mitochondrial Ca2+ uptake enhancers (MiCUps), efsevin and kaempferol, significantly reduced episodes of stress-induced ventricular tachycardia in RyR2R4496C/WT mice in vivo and abolished diastolic, arrhythmogenic Ca2+ events in human iPSC-derived cardiomyocytes.
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Affiliation(s)
- Maria K. Schweitzer
- Walther Straub Institute of Pharmacology and Toxicology, Ludwig-Maximilians-Universität München, Munich, Germany
| | - Fabiola Wilting
- Walther Straub Institute of Pharmacology and Toxicology, Ludwig-Maximilians-Universität München, Munich, Germany
| | - Simon Sedej
- Department of Cardiology, Medical University of Graz, Graz, Austria
| | - Lisa Dreizehnter
- Department of Medicine (Cardiology), Klinikum rechts der Isar, Technische Universität München, Munich, Germany
| | - Nathan J. Dupper
- Department of Chemistry and Biochemistry, University of California Los Angeles, Los Angeles, California
| | - Qinghai Tian
- Institute for Molecular Cell Biology, University Medical Center, Saarland University, Homburg/Saar, Germany
| | - Alessandra Moretti
- Department of Medicine (Cardiology), Klinikum rechts der Isar, Technische Universität München, Munich, Germany
- Deutsches Zentrum für Herz-Kreislauf-Forschung, Partner Site Munich Heart Alliance, Munich, Germany
| | - Ilaria My
- Department of Medicine (Cardiology), Klinikum rechts der Isar, Technische Universität München, Munich, Germany
| | - Ohyun Kwon
- Department of Chemistry and Biochemistry, University of California Los Angeles, Los Angeles, California
| | - Silvia G. Priori
- Molecular Cardiology, Istituto di ricovero e cura a carattere scientifico (IRCCS) Salvatore Maugeri Foundation, Pavia, Italy
- Department of Molecular Medicine, University of Pavia, Pavia, Italy
| | - Karl-Ludwig Laugwitz
- Department of Medicine (Cardiology), Klinikum rechts der Isar, Technische Universität München, Munich, Germany
- Deutsches Zentrum für Herz-Kreislauf-Forschung, Partner Site Munich Heart Alliance, Munich, Germany
| | - Ursula Storch
- Walther Straub Institute of Pharmacology and Toxicology, Ludwig-Maximilians-Universität München, Munich, Germany
| | - Peter Lipp
- Institute for Molecular Cell Biology, University Medical Center, Saarland University, Homburg/Saar, Germany
| | - Andreas Breit
- Walther Straub Institute of Pharmacology and Toxicology, Ludwig-Maximilians-Universität München, Munich, Germany
| | - Michael Mederos y Schnitzler
- Walther Straub Institute of Pharmacology and Toxicology, Ludwig-Maximilians-Universität München, Munich, Germany
- Deutsches Zentrum für Herz-Kreislauf-Forschung, Partner Site Munich Heart Alliance, Munich, Germany
| | - Thomas Gudermann
- Walther Straub Institute of Pharmacology and Toxicology, Ludwig-Maximilians-Universität München, Munich, Germany
- Deutsches Zentrum für Herz-Kreislauf-Forschung, Partner Site Munich Heart Alliance, Munich, Germany
| | - Johann Schredelseker
- Walther Straub Institute of Pharmacology and Toxicology, Ludwig-Maximilians-Universität München, Munich, Germany
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14
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Tsoutsoulopoulos A, Möhle N, Gohlsch K, Breit A, Mückter H, Gudermann T, Krischenowski O, Hoffmann S, Thiermann H, Steinritz D, Aufderheide M. The CULTEX ® Radial Flow System as in vivo model for the assessment of lung toxicity. Toxicol Lett 2017. [DOI: 10.1016/j.toxlet.2017.07.913] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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15
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Wagner FM, Koester L, Auberger T, Reuschel W, Mayr M, Kneschaurek P, Breit A, Schraube H. Fast Reactor Neutrons for the Treatment of Superficial Carcinomas. NUCL SCI ENG 2017. [DOI: 10.13182/nse92-a23873] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Affiliation(s)
- F. M. Wagner
- FRM—Reaktorstation Garching, Technische Universität München Federal Republic of Germany
| | - L. Koester
- FRM—Reaktorstation Garching, Technische Universität München Federal Republic of Germany
| | - Th. Auberger
- Institut für Strahlentherapie und Onkologie, Technische Universität München Federal Republic of Germany
| | - W. Reuschel
- Institut für Strahlentherapie und Onkologie, Technische Universität München Federal Republic of Germany
| | - M. Mayr
- Institut für Strahlentherapie und Onkologie, Technische Universität München Federal Republic of Germany
| | - P. Kneschaurek
- Institut für Strahlentherapie und Onkologie, Technische Universität München Federal Republic of Germany
| | - A. Breit
- Institut für Strahlentherapie und Onkologie, Technische Universität München Federal Republic of Germany
| | - H. Schraube
- GSF—Forschungszentrum für Umwelt und Gesundheit, Neuherberg Federal Republic of Germany
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16
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Stenger B, Steinritz D, Tsoutsoulopoulos A, Breit A, Thiermann H, Schmidt A, John H, Popp T, Gudermann T. Alkylating agents activate chemosensing Transient Receptor Potential A1 cation channels. Toxicol Lett 2016. [DOI: 10.1016/j.toxlet.2016.06.1870] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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17
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Breit A, Wicht K, Boekhoff I, Glas E, Lauffer L, Mückter H, Gudermann T. Glucose Enhances Basal or Melanocortin-Induced cAMP-Response Element Activity in Hypothalamic Cells. Mol Endocrinol 2016; 30:748-62. [PMID: 27144291 DOI: 10.1210/me.2016-1001] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
Melanocyte-stimulating hormone (MSH)-induced activation of the cAMP-response element (CRE) via the CRE-binding protein in hypothalamic cells promotes expression of TRH and thereby restricts food intake and increases energy expenditure. Glucose also induces central anorexigenic effects by acting on hypothalamic neurons, but the underlying mechanisms are not completely understood. It has been proposed that glucose activates the CRE-binding protein-regulated transcriptional coactivator 2 (CRTC-2) in hypothalamic neurons by inhibition of AMP-activated protein kinases (AMPKs), but whether glucose directly affects hypothalamic CRE activity has not yet been shown. Hence, we dissected effects of glucose on basal and MSH-induced CRE activation in terms of kinetics, affinity, and desensitization in murine, hypothalamic mHypoA-2/10-CRE cells that stably express a CRE-dependent reporter gene construct. Physiologically relevant increases in extracellular glucose enhanced basal or MSH-induced CRE-dependent gene transcription, whereas prolonged elevated glucose concentrations reduced the sensitivity of mHypoA-2/10-CRE cells towards glucose. Glucose also induced CRCT-2 translocation into the nucleus and the AMPK activator metformin decreased basal and glucose-induced CRE activity, suggesting a role for AMPK/CRTC-2 in glucose-induced CRE activation. Accordingly, small interfering RNA-induced down-regulation of CRTC-2 expression decreased glucose-induced CRE-dependent reporter activation. Of note, glucose also induced expression of TRH, suggesting that glucose might affect the hypothalamic-pituitary-thyroid axis via the regulation of hypothalamic CRE activity. These findings significantly advance our knowledge about the impact of glucose on hypothalamic signaling and suggest that TRH release might account for the central anorexigenic effects of glucose and could represent a new molecular link between hyperglycaemia and thyroid dysfunction.
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Affiliation(s)
- Andreas Breit
- Walther-Straub-Institut für Pharmakologie und Toxikologie, Ludwig-Maximilians-Universität München, 80336 Munich, Germany
| | - Kristina Wicht
- Walther-Straub-Institut für Pharmakologie und Toxikologie, Ludwig-Maximilians-Universität München, 80336 Munich, Germany
| | - Ingrid Boekhoff
- Walther-Straub-Institut für Pharmakologie und Toxikologie, Ludwig-Maximilians-Universität München, 80336 Munich, Germany
| | - Evi Glas
- Walther-Straub-Institut für Pharmakologie und Toxikologie, Ludwig-Maximilians-Universität München, 80336 Munich, Germany
| | - Lisa Lauffer
- Walther-Straub-Institut für Pharmakologie und Toxikologie, Ludwig-Maximilians-Universität München, 80336 Munich, Germany
| | - Harald Mückter
- Walther-Straub-Institut für Pharmakologie und Toxikologie, Ludwig-Maximilians-Universität München, 80336 Munich, Germany
| | - Thomas Gudermann
- Walther-Straub-Institut für Pharmakologie und Toxikologie, Ludwig-Maximilians-Universität München, 80336 Munich, Germany
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18
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Lauffer L, Glas E, Gudermann T, Breit A. Endogenous 5-HT2C Receptors Phosphorylate the cAMP Response Element Binding Protein via Protein Kinase C-Promoted Activation of Extracellular-Regulated Kinases-1/2 in Hypothalamic mHypoA-2/10 Cells. J Pharmacol Exp Ther 2016; 358:39-49. [PMID: 27189964 DOI: 10.1124/jpet.116.232397] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2016] [Accepted: 04/25/2016] [Indexed: 02/01/2023] Open
Abstract
Serotonin 5-HT2C receptors (5-HT2CR) activate Gq proteins and are expressed in the central nervous system (CNS). 5-HT2CR regulate emotion, feeding, reward, or cognition and may serve as promising drug targets to treat psychiatric disorders or obesity. Owing to technical difficulties in isolating cells from the CNS and the lack of suitable cell lines endogenously expressing 5-HT2CR, our knowledge about this receptor subtype in native environments is rather limited. The hypothalamic mHypoA-2/10 cell line was recently established and resembles appetite-regulating hypothalamic neurons of the paraventricular nucleus (PVN), where 5-HT2CR have been detected in vivo. Therefore, we tested mHypoA-2/10 cells for endogenous 5-HT2CR expression. Serotonin or the 5-HT2CR preferential agonist WAY-161,503 initiated cAMP response element (CRE)-dependent gene transcription with EC50 values of 15.5 ± 9.8 and 1.1 ± 0.9 nM, respectively. Both responses were blocked by two unrelated 5-HT2CR-selective antagonists (SB-242,084, RS-102,221) but not by a 5-HT2AR (EMD-281,014) or 5-HT2BR (RS-127,455) antagonists. By single-cell calcium imaging, we found that serotonin and WAY-161,503 induced robust calcium transients, which were also blunted by both 5-HT2CR antagonists. Additionally we revealed, first, that 5-HT2CR induced CRE activation via protein kinase C (PKC)-mediated engagement of extracellular-regulated kinases-1/2 and, second, that intrinsic activity of WAY-161,503 was in the range of 0.3-0.5 compared with serotonin, defining the frequently used 5-HT2CR agonist as a partial agonist of endogenous 5-HT2CR. In conclusion, we have shown that hypothalamic mHypoA-2/10 cells endogenously express 5-HT2CR and thus are the first cell line in which to analyze 5-HT2CR pharmacology, signaling, and regulation in its natural environment.
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Affiliation(s)
- Lisa Lauffer
- Walther-Straub-Institut für Pharmakologie und Toxikologie, Ludwig-Maximilians-Universität München, München, Germany
| | - Evi Glas
- Walther-Straub-Institut für Pharmakologie und Toxikologie, Ludwig-Maximilians-Universität München, München, Germany
| | - Thomas Gudermann
- Walther-Straub-Institut für Pharmakologie und Toxikologie, Ludwig-Maximilians-Universität München, München, Germany
| | - Andreas Breit
- Walther-Straub-Institut für Pharmakologie und Toxikologie, Ludwig-Maximilians-Universität München, München, Germany
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19
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Borth H, Weber N, Meyer D, Wartenberg A, Arlt E, Zierler S, Breit A, Wennemuth G, Gudermann T, Boekhoff I. The IP3 R Binding Protein Released With Inositol 1,4,5-Trisphosphate Is Expressed in Rodent Reproductive Tissue and Spermatozoa. J Cell Physiol 2015; 231:1114-29. [PMID: 26439876 DOI: 10.1002/jcp.25209] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2015] [Accepted: 09/30/2015] [Indexed: 11/08/2022]
Abstract
Besides its capacity to inhibit the 1,4,5-trisphosphate (IP3) receptor, the regulatory protein IRBIT (IP3 receptor binding protein released with IP3) is also able to control the activity of numerous ion channels and electrolyte transporters and thereby creates an optimal electrolyte composition of various biological fluids. Since a reliable execution of spermatogenesis and sperm maturation critically depends on the establishment of an adequate microenvironment, the expression of IRBIT in male reproductive tissue was examined using immunohistochemical approaches combined with biochemical fractionation methods. The present study documents that IRBIT is expressed in Leydig and Sertoli cells. In addition, pronounced IRBIT expression was detected in sperm precursors during early stages of spermatogenesis as well as in spermatozoa. Analyzing tissue sections of rodent epididymides, IRBIT was found to co-localize with the proton pumping V-ATPase and the cystic fibrosis transmembrane conductance regulator (CFTR) at the apical surface of narrow and clear cells. A similar co-localization of IRBIT with CFTR was also observed for Sertoli cells and developing germ cells. Remarkably, assaying caudal sperm in immunogold electron microscopy, IRBIT was found to localize to the acrosomal cap and the flagellum as well as to the sperm nucleus; moreover, a prominent oligomerization was observed for spermatozoa. The pronounced occurrence of IRBIT in the male reproductive system and mature spermatozoa indicates a potential role for IRBIT in establishing the essential luminal environment for a faithful execution of spermatogenesis and epididymal sperm maturation, and suggest a participation of IRBIT during maturation steps after ejaculation and/or the final fertilization process.
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Affiliation(s)
- Heike Borth
- Walther Straub Institute of Pharmacology and Toxicology, Ludwig-Maximilians-Universit, ä, t M, ü, nchen, München, Germany
| | - Nele Weber
- Walther Straub Institute of Pharmacology and Toxicology, Ludwig-Maximilians-Universit, ä, t M, ü, nchen, München, Germany
| | - Dorke Meyer
- Walther Straub Institute of Pharmacology and Toxicology, Ludwig-Maximilians-Universit, ä, t M, ü, nchen, München, Germany
| | - Andrea Wartenberg
- Walther Straub Institute of Pharmacology and Toxicology, Ludwig-Maximilians-Universit, ä, t M, ü, nchen, München, Germany
| | - Elisabeth Arlt
- Walther Straub Institute of Pharmacology and Toxicology, Ludwig-Maximilians-Universit, ä, t M, ü, nchen, München, Germany
| | - Susanna Zierler
- Walther Straub Institute of Pharmacology and Toxicology, Ludwig-Maximilians-Universit, ä, t M, ü, nchen, München, Germany
| | - Andreas Breit
- Walther Straub Institute of Pharmacology and Toxicology, Ludwig-Maximilians-Universit, ä, t M, ü, nchen, München, Germany
| | - Gunther Wennemuth
- Department of Anatomy, University Clinic Essen, University of Duisburg-Essen, Germany
| | - Thomas Gudermann
- Walther Straub Institute of Pharmacology and Toxicology, Ludwig-Maximilians-Universit, ä, t M, ü, nchen, München, Germany
| | - Ingrid Boekhoff
- Walther Straub Institute of Pharmacology and Toxicology, Ludwig-Maximilians-Universit, ä, t M, ü, nchen, München, Germany
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Abstract
Signaling by heptahelical G protein-coupled receptors (GPCR) regulates many vital body functions. Consequently, dysfunction of GPCR signaling leads to pathologic states, and approximately 30% of all modern clinical drugs target GPCR. One decade ago, an entire new GPCR family was discovered, which was recently named MAS-related G protein-coupled receptors (MRGPR) by the HUGO Gene Nomenclature Committee. The MRGPR family consists of ∼40 members that are grouped into nine distinct subfamilies (MRGPRA to -H and -X) and are predominantly expressed in primary sensory neurons and mast cells. All members are formally still considered "orphan" by the Committee on Receptor Nomenclature and Drug Classification of the International Union of Basic and Clinical Pharmacology. However, several distinct peptides and amino acids are discussed as potential ligands, including β-alanine, angiotensin-(1-7), alamandine, GABA, cortistatin-14, and cleavage products of proenkephalin, pro-opiomelanocortin, prodynorphin, or proneuropeptide-FF-A. The full spectrum of biologic roles of all MRGPR is still ill-defined, but there is evidence pointing to a role of distinct MRGPR subtypes in nociception, pruritus, sleep, cell proliferation, circulation, and mast cell degranulation. This review article summarizes findings published in the last 10 years on the phylogenetic relationships, pharmacology, signaling, physiology, and agonist-promoted regulation of all MRGPR subfamilies. Furthermore, we highlight interactions between MRGPR and other hormonal systems, paying particular attention to receptor multimerization and morphine tolerance. Finally, we discuss the challenges the field faces presently and emphasize future directions of research.
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Affiliation(s)
- Hans Jürgen Solinski
- Walther-Straub-Institut für Pharmakologie und Toxikologie, Ludwig-Maximilians-Universität München, Munich, Germany
| | - Thomas Gudermann
- Walther-Straub-Institut für Pharmakologie und Toxikologie, Ludwig-Maximilians-Universität München, Munich, Germany
| | - Andreas Breit
- Walther-Straub-Institut für Pharmakologie und Toxikologie, Ludwig-Maximilians-Universität München, Munich, Germany
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Breit A, Besik V, Solinski HJ, Muehlich S, Glas E, Yarwood SJ, Gudermann T. Serine-727 phosphorylation activates hypothalamic STAT-3 independently from tyrosine-705 phosphorylation. Mol Endocrinol 2015; 29:445-59. [PMID: 25584415 DOI: 10.1210/me.2014-1300] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
Transcriptional activity of signal transducer and activator of transcription-3 (STAT-3) is a key element in the central regulation of appetite and energy homeostasis. Activation of hypothalamic STAT-3 has been attributed to cytokine-promoted phosphorylation at tyrosine-705 (Tyr-705). In nonhypothalamic cells, STAT-3 is also phosphorylated at serine-727 (Ser-727), but the functional significance of Ser-727 in the regulation of hypothalamic STAT-3 is not known. We used 2 hypothalamic cell lines and analyzed the effects of various hormones on STAT-3-dependent reporter gene activity and observed that IFN-γ, epidermal growth factor (EGF), and bradykinin (BK) induce similar STAT-3 reporter activation. EGF and BK solely increased Ser-727 and IFN-γ increased Tyr-705 phosphorylation of STAT-3. Specific inhibition of ERK-1/2 activity blocked EGF- and BK-induced STAT-3 activation and Ser-727 phosphorylation. BK-induced ERK-1/2 activation occurred via EGF receptor transactivation. Consequently, the BK-mediated effects on STAT-3 were blocked by a specific EGF receptor antagonist. Next, we analyzed the effects of IFN-γ and EGF on the expression of the STAT-3-dependent genes thyroliberin-releasing hormone and suppressors of cytokine signaling-3. EGF but not IFN-γ enhanced thyroliberin-releasing hormone expression via STAT-3. With regard to suppressors of cytokine signaling-3, we observed prolonged expression induced by IFN-γ and a transient effect of EGF that required coactivation of the activator protein-1. Thus, EGF-promoted Ser-727 phosphorylation by ERK-1/2 is not only sufficient to fully activate hypothalamic STAT-3, but, in terms of targeted genes and required cofactors, entails distinct modes of STAT-3 actions compared with IFN-γ-induced Tyr-705 phosphorylation.
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Affiliation(s)
- Andreas Breit
- Walther-Straub-Institut für Pharmakologie und Toxikologie (A.B., V.B., H.J.S., S.M., E.G., T.G.), Ludwig-Maximilians-Universität München, München, Germany 80336; and The Institute of Molecular, Cell and Systems Biology (S.J.Y.), College of Medical, Veterinary and Life Science, University of Glasgow, Glasgow GC12 8QQ, United Kingdom
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22
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Weber N, Vieweg L, Henze F, Oprisoreanu AM, Solinski HJ, Breit A, Fecher-Trost C, Schalkowsky P, Wilhelm B, Wennemuth G, Schoch S, Gudermann T, Boekhoff I. RIM2α is a molecular scaffold for Zona pellucida-induced acrosome reaction. J Mol Cell Biol 2014; 6:434-7. [DOI: 10.1093/jmcb/mju037] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Abstract
Adducin is a protein organizing the cortical actin cytoskeleton and a target of RhoA and PKC signaling. However, the role for intercellular cohesion is unknown. We found that adducin silencing induced disruption of the actin cytoskeleton, reduced intercellular adhesion of human keratinocytes, and decreased the levels of the desmosomal adhesion molecule desmoglein (Dsg)3 by reducing its membrane incorporation. Because loss of cell cohesion and Dsg3 depletion is observed in the autoantibody-mediated blistering skin disease pemphigus vulgaris (PV), we applied antibody fractions of PV patients. A rapid phosphorylation of adducin at serine 726 was detected in response to these autoantibodies. To mechanistically link autoantibody binding and adducin phosphorylation, we evaluated the role of several disease-relevant signaling molecules. Adducin phosphorylation at serine 726 was dependent on Ca(2+) influx and PKC but occurred independent of p38 MAPK and PKA. Adducin phosphorylation is protective, because phosphorylation-deficient mutants resulted in loss of cell cohesion and Dsg3 fragmentation. Thus, PKC elicits both positive and negative effects on cell adhesion, since its contribution to cell dissociation in pemphigus is well established. We additionally evaluated the effect of RhoA on adducin phosphorylation because RhoA activation was shown to block pemphigus autoantibody-induced cell dissociation. Our data demonstrate that the protective effect of RhoA activation was dependent on the presence of adducin and its phosphorylation at serine 726. These experiments provide novel mechanisms for regulation of desmosomal adhesion by RhoA- and PKC-mediated adducin phosphorylation in keratinocytes.
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Affiliation(s)
- Vera Rötzer
- From the Institute of Anatomy and Cell Biology, Ludwig-Maximilians-Universität, Munich D-80336 and
| | - Andreas Breit
- the Walther-Straub-Institute for Pharmacology and Toxicology, Ludwig-Maximilians-Universität, Munich D-80336, Germany
| | - Jens Waschke
- From the Institute of Anatomy and Cell Biology, Ludwig-Maximilians-Universität, Munich D-80336 and
| | - Volker Spindler
- From the Institute of Anatomy and Cell Biology, Ludwig-Maximilians-Universität, Munich D-80336 and
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Arndt L, Castonguay J, Arlt E, Meyer D, Hassan S, Borth H, Zierler S, Wennemuth G, Breit A, Biel M, Wahl-Schott C, Gudermann T, Klugbauer N, Boekhoff I. NAADP and the two-pore channel protein 1 participate in the acrosome reaction in mammalian spermatozoa. Mol Biol Cell 2014; 25:948-64. [PMID: 24451262 PMCID: PMC3952862 DOI: 10.1091/mbc.e13-09-0523] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
A TPCN1 gene–deficient mouse strain is used to show that two convergent working NAADP-dependent pathways with nonoverlapping activation and self-inactivation profiles for distinct NAADP concentrations drive acrosomal exocytosis, by which TPC1 is central for the pathway activated by low-micromolar NAADP concentrations. The functional relationship between the formation of hundreds of fusion pores during the acrosome reaction in spermatozoa and the mobilization of calcium from the acrosome has been determined only partially. Hence, the second messenger NAADP, promoting efflux of calcium from lysosome-like compartments and one of its potential molecular targets, the two-pore channel 1 (TPC1), were analyzed for its involvement in triggering the acrosome reaction using a TPCN1 gene–deficient mouse strain. The present study documents that TPC1 and NAADP-binding sites showed a colocalization at the acrosomal region and that treatment of spermatozoa with NAADP resulted in a loss of the acrosomal vesicle that showed typical properties described for TPCs: Registered responses were not detectable for its chemical analogue NADP and were blocked by the NAADP antagonist trans-Ned-19. In addition, two narrow bell-shaped dose-response curves were identified with maxima in either the nanomolar or low micromolar NAADP concentration range, where TPC1 was found to be responsible for activating the low affinity pathway. Our finding that two convergent NAADP-dependent pathways are operative in driving acrosomal exocytosis supports the concept that both NAADP-gated cascades match local NAADP concentrations with the efflux of acrosomal calcium, thereby ensuring complete fusion of the large acrosomal vesicle.
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Affiliation(s)
- Lilli Arndt
- Walther Straub Institute of Pharmacology and Toxicology, Ludwig-Maximilians University, 81377 München, Germany Department of Pharmacy, Ludwig-Maximilians University, 81377 München, Germany Institute for Experimental and Clinical Pharmacology and Toxicology, Albert-Ludwigs-University, 79104 Freiburg, Germany Institute for Anatomy, University of Duisburg-Essen, 45141 Essen, Germany
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Breit A. VERSCHLUSSE DER ARTERIA CEREBRI MEDIA. Acta Radiol 2013. [DOI: 10.1177/028418515805000113] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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Stein M, Breit A, Fehrentz T, Gudermann T, Trauner D. Optical control of TRPV1 channels. Angew Chem Int Ed Engl 2013; 52:9845-8. [PMID: 23873837 DOI: 10.1002/anie.201302530] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2013] [Revised: 05/09/2013] [Indexed: 11/10/2022]
Affiliation(s)
- Marco Stein
- Department of Chemistry, Ludwig-Maximilians-University, Munich and Center of Integrated Protein Science, Butenandtstrasse 5-13, 81377 Munich, Germany
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Solinski HJ, Petermann F, Rothe K, Boekhoff I, Gudermann T, Breit A. Human Mas-related G protein-coupled receptors-X1 induce chemokine receptor 2 expression in rat dorsal root ganglia neurons and release of chemokine ligand 2 from the human LAD-2 mast cell line. PLoS One 2013; 8:e58756. [PMID: 23505557 PMCID: PMC3591377 DOI: 10.1371/journal.pone.0058756] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2013] [Accepted: 02/06/2013] [Indexed: 12/16/2022] Open
Abstract
Primate-specific Mas-related G protein-coupled receptors-X1 (MRGPR-X1) are highly enriched in dorsal root ganglia (DRG) neurons and induce acute pain. Herein, we analyzed effects of MRGPR-X1 on serum response factors (SRF) or nuclear factors of activated T cells (NFAT), which control expression of various markers of chronic pain. Using HEK293, DRG neuron-derived F11 cells and cultured rat DRG neurons recombinantly expressing human MRGPR-X1, we found activation of a SRF reporter gene construct and induction of the early growth response protein-1 via extracellular signal-regulated kinases-1/2 known to play a significant role in the development of inflammatory pain. Furthermore, we observed MRGPR-X1-induced up-regulation of the chemokine receptor 2 (CCR2) via NFAT, which is considered as a key event in the onset of neuropathic pain and, so far, has not yet been described for any endogenous neuropeptide. Up-regulation of CCR2 is often associated with increased release of its endogenous agonist chemokine ligand 2 (CCL2). We also found MRGPR-X1-promoted release of CCL2 in a human connective tissue mast cell line endogenously expressing MRGPR-X1. Thus, we provide first evidence to suggest that MRGPR-X1 induce expression of chronic pain markers in DRG neurons and propose a so far unidentified signaling circuit that enhances chemokine signaling by acting on two distinct yet functionally co-operating cell types. Given the important role of chemokine signaling in pain chronification, we propose that interruption of this signaling circuit might be a promising new strategy to alleviate chemokine-promoted pain.
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MESH Headings
- Animals
- Bradykinin/pharmacology
- Calcineurin/metabolism
- Calcium/metabolism
- Cell Line
- Chemokine CCL2/metabolism
- Early Growth Response Protein 1/genetics
- Early Growth Response Protein 1/metabolism
- Enzyme Activation/drug effects
- Ganglia, Spinal/metabolism
- Gene Expression Regulation/drug effects
- Genes, fos
- HEK293 Cells
- Humans
- Inositol 1,4,5-Trisphosphate Receptors/genetics
- Inositol 1,4,5-Trisphosphate Receptors/metabolism
- Mast Cells/metabolism
- Mitogen-Activated Protein Kinase 1/metabolism
- Mitogen-Activated Protein Kinase 3/metabolism
- NFATC Transcription Factors/metabolism
- Peptide Fragments/pharmacology
- Rats
- Receptors, CCR2/genetics
- Receptors, CCR2/metabolism
- Receptors, G-Protein-Coupled/antagonists & inhibitors
- Receptors, G-Protein-Coupled/genetics
- Receptors, G-Protein-Coupled/metabolism
- Sensory Receptor Cells/metabolism
- Serum Response Factor/metabolism
- Ternary Complex Factors/metabolism
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Affiliation(s)
- Hans Jürgen Solinski
- Walther-Straub-Institut für Pharmakologie und Toxikologie, Ludwig-Maximilians-Universität München, Munich, Germany
| | - Franziska Petermann
- Department of Neurology, Klinikum rechts der Isar, Technical University Munich, Munich, Germany
| | - Kathrin Rothe
- Walther-Straub-Institut für Pharmakologie und Toxikologie, Ludwig-Maximilians-Universität München, Munich, Germany
| | - Ingrid Boekhoff
- Walther-Straub-Institut für Pharmakologie und Toxikologie, Ludwig-Maximilians-Universität München, Munich, Germany
| | - Thomas Gudermann
- Walther-Straub-Institut für Pharmakologie und Toxikologie, Ludwig-Maximilians-Universität München, Munich, Germany
| | - Andreas Breit
- Walther-Straub-Institut für Pharmakologie und Toxikologie, Ludwig-Maximilians-Universität München, Munich, Germany
- * E-mail:
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Bäck CM, Stohr S, Schäfer EAM, Biebermann H, Boekhoff I, Breit A, Gudermann T, Büch TRH. TSH induces metallothionein 1 in thyrocytes via Gq/11- and PKC-dependent signaling. J Mol Endocrinol 2013; 51:79-90. [PMID: 23613280 DOI: 10.1530/jme-12-0200] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Metallothioneins (MTs) are cytoprotective proteins acting as scavengers of toxic metal ions or reactive oxygen species. MTs are upregulated in follicular thyroid carcinoma and are regarded as a marker of thyroid stress in Graves' disease. However, the mechanism of MT regulation in thyrocytes is still elusive. In other cellular systems, cAMP-, calcium-, or protein kinase C (PKC)-dependent signaling cascades have been shown to induce MT expression. Of note, all of these three pathways are activated following the stimulation of the TSH receptor (TSHR). Thus, we hypothesized that TSH represents a key regulator of MT expression in thyrocytes. In fact, TSHR stimulation induced expression of MT isoform 1X (MT1X) in human follicular carcinoma cells. In these cells, Induction of MT1X expression critically relied on intact Gq/11 signaling of the TSHR and was blocked by chelation of intracellular calcium and inhibition of PKC. TSHR-independent stimulation of cAMP formation by treating cells with forskolin also led to an upregulation of MT1X, which was completely dependent on PKA. However, inhibition of PKA did not affect the regulation of MT1X by TSH. As in follicular thyroid carcinoma cells, TSH also induced MT1 protein in primary human thyrocytes, which was PKC dependent as well. In summary, these findings indicate that TSH stimulation induces MT1X expression via Gq/11 and PKC, whereas cAMP-PKA signaling does not play a predominant role. To date, little has been known regarding cAMP-independent effects of TSHR signaling. Our findings extend the knowledge about the PKC-mediated functions of the TSHR.
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Affiliation(s)
- Christer M Bäck
- Medical Department III, University Hospital Aachen, D-52074 Aachen, Germany
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Solinski HJ, Zierler S, Gudermann T, Breit A. Human sensory neuron-specific Mas-related G protein-coupled receptors-X1 sensitize and directly activate transient receptor potential cation channel V1 via distinct signaling pathways. J Biol Chem 2012; 287:40956-71. [PMID: 23074220 DOI: 10.1074/jbc.m112.408617] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Sensory neuron-specific Mas-related G protein-coupled receptors-X1 (MRGPR-X1) are primate-specific proteins that are exclusively expressed in primary sensory neurons and provoke pain in humans. Hence, MRGPR-X1 represent promising targets for future pain therapy, but signaling pathways activated by MRGPR-X1 are poorly understood. The transient receptor potential cation channel V1 (TRPV1) is also expressed in primary sensory neurons and detects painful stimuli such as protons and heat. G(q)-promoted signaling has been shown to sensitize TRPV1 via protein kinase C (PKC)-dependent phosphorylation. In addition, recent studies suggested TRPV1 activation via a G(q)-mediated mechanism involving diacylglycerol (DAG) or phosphatidylinositol-4,5-bisphosphate (PIP(2)). However, it is not clear if DAG-promoted TRPV1 activation occurs independently from classic TRPV1 activation modes induced by heat and protons. Herein, we analyzed putative functional interactions between MRGPR-X1 and TRPV1 in a previously reported F11 cell line stably over-expressing MRGPR-X1. First, we found that MRGPR-X1 sensitized TRPV1 to heat and protons in a PKC-dependent manner. Second, we observed direct MRGPR-X1-mediated TRPV1 activation independent of MRGPR-X1-induced Ca(2+)-release and PKC activity or other TRPV1 affecting enzymes such as lipoxygenase, extracellular signal-regulated kinases-1/2, sarcoma, or phosphoinositide 3-kinase. Investigating several TRPV1 mutants, we observed that removal of the TRPV1 binding site for DAG and of the putative PIP(2) sensor decreased MRGPR-X1-induced TRPV1 activation by 71 and 43%, respectively. Therefore, we demonstrate dual functional interactions between MRGPR-X1 and TRPV1, resulting in PKC-dependent TRPV1 sensitization and DAG/PIP(2)-mediated activation. The molecular discrimination between TRPV1 sensitization and activation may help improve the specificity of current pain therapies.
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Affiliation(s)
- Hans Jürgen Solinski
- Walther-Straub-Institut für Pharmakologie und Toxikologie, Ludwig-Maximilians-Universität München 80336 München, Germany
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Rothe K, Solinski HJ, Boekhoff I, Gudermann T, Breit A. Morphine Activates the E Twenty Six-Like Transcription Factor-1/Serum Response Factor Pathway via Extracellular Signal-Regulated Kinases 1/2 in F11 Cells Derived from Dorsal Root Ganglia Neurons. J Pharmacol Exp Ther 2012; 342:41-52. [DOI: 10.1124/jpet.112.192757] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
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33
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Meyer D, Voigt A, Widmayer P, Borth H, Huebner S, Breit A, Marschall S, de Angelis MH, Boehm U, Meyerhof W, Gudermann T, Boekhoff I. Expression of Tas1 taste receptors in mammalian spermatozoa: functional role of Tas1r1 in regulating basal Ca²⁺ and cAMP concentrations in spermatozoa. PLoS One 2012; 7:e32354. [PMID: 22427794 PMCID: PMC3303551 DOI: 10.1371/journal.pone.0032354] [Citation(s) in RCA: 55] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2011] [Accepted: 01/25/2012] [Indexed: 12/03/2022] Open
Abstract
BACKGROUND During their transit through the female genital tract, sperm have to recognize and discriminate numerous chemical compounds. However, our current knowledge of the molecular identity of appropriate chemosensory receptor proteins in sperm is still rudimentary. Considering that members of the Tas1r family of taste receptors are able to discriminate between a broad diversity of hydrophilic chemosensory substances, the expression of taste receptors in mammalian spermatozoa was examined. METHODOLOGY/PRINCIPAL FINDINGS The present manuscript documents that Tas1r1 and Tas1r3, which form the functional receptor for monosodium glutamate (umami) in taste buds on the tongue, are expressed in murine and human spermatozoa, where their localization is restricted to distinct segments of the flagellum and the acrosomal cap of the sperm head. Employing a Tas1r1-deficient mCherry reporter mouse strain, we found that Tas1r1 gene deletion resulted in spermatogenic abnormalities. In addition, a significant increase in spontaneous acrosomal reaction was observed in Tas1r1 null mutant sperm whereas acrosomal secretion triggered by isolated zona pellucida or the Ca²⁺ ionophore A23187 was not different from wild-type spermatozoa. Remarkably, cytosolic Ca²⁺ levels in freshly isolated Tas1r1-deficient sperm were significantly higher compared to wild-type cells. Moreover, a significantly higher basal cAMP concentration was detected in freshly isolated Tas1r1-deficient epididymal spermatozoa, whereas upon inhibition of phosphodiesterase or sperm capacitation, the amount of cAMP was not different between both genotypes. CONCLUSIONS/SIGNIFICANCE Since Ca²⁺ and cAMP control fundamental processes during the sequential process of fertilization, we propose that the identified taste receptors and coupled signaling cascades keep sperm in a chronically quiescent state until they arrive in the vicinity of the egg - either by constitutive receptor activity and/or by tonic receptor activation by gradients of diverse chemical compounds in different compartments of the female reproductive tract.
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MESH Headings
- Animals
- Blotting, Western
- Calcium/metabolism
- Cyclic AMP/metabolism
- Female
- Gene Expression
- Humans
- Luminescent Proteins/genetics
- Luminescent Proteins/metabolism
- Male
- Mice
- Mice, 129 Strain
- Mice, Inbred BALB C
- Mice, Inbred C57BL
- Mice, Knockout
- Mice, Transgenic
- Microscopy, Confocal
- Models, Biological
- RNA, Messenger/genetics
- RNA, Messenger/metabolism
- Rats
- Rats, Wistar
- Receptors, G-Protein-Coupled/genetics
- Receptors, G-Protein-Coupled/metabolism
- Receptors, G-Protein-Coupled/physiology
- Reverse Transcriptase Polymerase Chain Reaction
- Sperm Head/metabolism
- Spermatozoa/metabolism
- Testis/cytology
- Testis/metabolism
- Red Fluorescent Protein
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Affiliation(s)
- Dorke Meyer
- Walther-Straub Institute of Pharmacology and
Toxicology, Ludwig-Maximilians-University, Munich, Germany
| | - Anja Voigt
- German Institute of Nutrition,
Potsdam-Rehbruecke, Germany
- Institute for Neural Signal Transduction,
Center for Molecular Neurobiology, Hamburg, Germany
| | - Patricia Widmayer
- Institute of Physiology, University of
Hohenheim, Stuttgart, Germany
| | - Heike Borth
- Walther-Straub Institute of Pharmacology and
Toxicology, Ludwig-Maximilians-University, Munich, Germany
| | - Sandra Huebner
- German Institute of Nutrition,
Potsdam-Rehbruecke, Germany
| | - Andreas Breit
- Walther-Straub Institute of Pharmacology and
Toxicology, Ludwig-Maximilians-University, Munich, Germany
| | - Susan Marschall
- Institute of Experimental Genetics,
Helmholtz-Zentrum, Munich, Germany
| | | | - Ulrich Boehm
- Institute for Neural Signal Transduction,
Center for Molecular Neurobiology, Hamburg, Germany
| | | | - Thomas Gudermann
- Walther-Straub Institute of Pharmacology and
Toxicology, Ludwig-Maximilians-University, Munich, Germany
| | - Ingrid Boekhoff
- Walther-Straub Institute of Pharmacology and
Toxicology, Ludwig-Maximilians-University, Munich, Germany
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Damm E, Buech TRH, Gudermann T, Breit A. Melanocortin-induced PKA activation inhibits AMPK activity via ERK-1/2 and LKB-1 in hypothalamic GT1-7 cells. Mol Endocrinol 2012; 26:643-54. [PMID: 22361823 DOI: 10.1210/me.2011-1218] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
α-Melanocyte-stimulating hormone (α-MSH)-induced activation of the melanocortin-4 receptor in hypothalamic neurons increases energy expenditure and inhibits food intake. Active hypothalamic AMP-activated protein kinase (AMPK) has recently been reported to enhance food intake, and in vivo experiments suggested that intrahypothalamic injection of melanocortins decreased food intake due to the inhibition of AMPK activity. However, it is not clear whether α-MSH affects AMPK via direct intracellular signaling cascades or if the release of paracrine factors is involved. Here, we used a murine, hypothalamic cell line (GT1-7 cells) and monitored AMPK phosphorylation at Thr(172), which has been suggested to increase AMPK activity. We found that α-MSH dephosphorylated AMPK at Thr(172) and consequently decreased phosphorylation of the established AMPK substrate acetyl-coenzyme A-carboxylase at Ser(79). Inhibitory effects of α-MSH on AMPK were blocked by specific inhibitors of protein kinase A (PKA) or ERK-1/2, pointing to an important role of both kinases in this process. Because α-MSH-induced activation of ERK-1/2 was blunted by PKA inhibitors, we propose that ERK-1/2 serves as a link between PKA and AMPK in GT1-7 cells. Furthermore, down-regulation of liver kinase B-1, but not inhibition of calcium-calmodulin-dependent kinase kinase-β or TGFβ-activated kinase-1 decreased basal phosphorylation of AMPK and its dephosphorylation induced by α-MSH. Thus, we propose that α-MSH inhibits AMPK activity via a linear pathway, including PKA, ERK-1/2, and liver kinase B-1 in GT1-7 cells. Given the importance of the melanocortin system in the formation of adipositas, detailed knowledge about this pathway might help to develop drugs targeting obesity.
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Affiliation(s)
- Ellen Damm
- Walther-Straub-Institut für Pharmakologie und Toxikologie, Ludwig-Maximilians-Universität, Goethestrasse 33, 80336 München, Germany
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Breit A, Büch TRH, Boekhoff I, Solinski HJ, Damm E, Gudermann T. Alternative G protein coupling and biased agonism: new insights into melanocortin-4 receptor signalling. Mol Cell Endocrinol 2011; 331:232-40. [PMID: 20674667 DOI: 10.1016/j.mce.2010.07.007] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/26/2010] [Revised: 05/06/2010] [Accepted: 07/13/2010] [Indexed: 11/20/2022]
Abstract
The melanocortin-4 receptor (MC4R) is a prototypical G protein-coupled receptor (GPCR) that plays a considerable role in controlling appetite and energy homeostasis. Signalling initiated by MC4R is orchestrated by multiple agonists, inverse agonism and by interactions with accessory proteins. The exact molecular events translating MC4R signalling into its physiological role, however, are not fully understood. This review is an attempt to summarize new aspects of MC4R signalling in the context of its recently discovered alternative G protein coupling, and to give a perspective on how future research could improve our knowledge about the intertwining molecular mechanisms that are responsible for the regulation of energy homeostasis by the melanocortin system.
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Affiliation(s)
- Andreas Breit
- Walther-Straub-Institut für Pharmakologie und Toxikologie, Goethestrasse 33, Ludwig-Maximilians-Universität München, 80336 München, Germany.
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36
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Zitranski N, Borth H, Ackermann F, Meyer D, Vieweg L, Breit A, Gudermann T, Boekhoff I. The "acrosomal synapse": Subcellular organization by lipid rafts and scaffolding proteins exhibits high similarities in neurons and mammalian spermatozoa. Commun Integr Biol 2010; 3:513-21. [PMID: 21331227 DOI: 10.4161/cib.3.6.13137] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2010] [Revised: 07/23/2010] [Accepted: 07/23/2010] [Indexed: 12/18/2022] Open
Abstract
Mammalian spermatozoa are highly polarized cells composed of two morphological and functional units, each optimized for a special task. Although the apparent division into head and tail may as such represent the anatomical basis to avoid random diffusion of their special sets of signaling proteins and lipids, recent findings demonstrate the presence of lipid raft-derived membrane platforms and specific scaffolding proteins, thus indicating that smaller sub-domains exist in the two functional units of male germ cells. The aim of this review is to summarize new insights into the principles of subcellular organization in mammalian spermatozoa. Special emphasis is placed on recent observations indicating that an "acrosomal synapse" is formed by lipid raft-derived membrane micro-environments and multidomain scaffolding proteins. Both mechanisms appear to be responsible for ensuring the attachment of the huge acrosomal vesicle to the overlaying plasma membrane, as well as for preventing an accidental spontaneous loss of the single acrosome.
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Affiliation(s)
- Nele Zitranski
- Walther-Straub-Institute of Pharmacology and Toxicology; Ludwig-Maximilians-University; Munich, Germany
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Solinski HJ, Boekhoff I, Bouvier M, Gudermann T, Breit A. Sensory neuron-specific MAS-related gene-X1 receptors resist agonist-promoted endocytosis. Mol Pharmacol 2010; 78:249-59. [PMID: 20424127 DOI: 10.1124/mol.110.063867] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Abstract
Human sensory neuron-specific mas-related gene X1 receptors (hMrgX1s) belong to the superfamily of G protein-coupled receptors (GPCRs), bind cleavage products of pro-enkephalin with high affinity, and have been suggested to participate in pain sensation. Murine or rat MrgC receptors exhibit high similarities with hMrgX1 in terms of expression pattern, sequence homology, and binding profile. Therefore, rodents have been used as an in vivo model to explore the physiological functions and pharmacodynamics of the hMrgX1. Agonist-promoted receptor endocytosis significantly affects the pharmacodynamics of a GPCR but is not yet investigated for hMrgX1. Therefore, we analyzed the effects of prolonged agonist exposure on cell surface protein levels of hMrgX1 and murine or rat MrgC in human embryonic kidney 293, Cos, F11, and ND-C cells. We observed that hMrgX1 are resistant and both MrgC are prone to agonist-promoted receptor endocytosis. In Cos cells, coexpression of beta-arrestins strongly enhanced endocytosis of murine MrgC but did not alter cell surface expression of hMrgX1 receptors. These data define the hMrgX1 as one of the few members within the superfamily of GPCRs whose signaling is not regulated by agonist-promoted endocytosis and reveal species-specific differences in the regulation of Mrg receptor signaling. Given the importance of receptor endocytosis for the pharmacodynamics of a given ligand, our results may have a strong impact on the development of future drugs that suppose to control pain in humans but were tested in rodents.
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Affiliation(s)
- Hans Jürgen Solinski
- Walther-Straub-Institut für Pharmakologie und Toxikologie, Ludwig-Maximilians-Universität München, 80336 München, Germany
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39
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40
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Büch TRH, Heling D, Damm E, Gudermann T, Breit A. Pertussis toxin-sensitive signaling of melanocortin-4 receptors in hypothalamic GT1-7 cells defines agouti-related protein as a biased agonist. J Biol Chem 2009; 284:26411-20. [PMID: 19648111 DOI: 10.1074/jbc.m109.039339] [Citation(s) in RCA: 84] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Melanocortin-4 receptor (MC4R)-induced anorexigenic signaling in the hypothalamus controls body weight and energy homeostasis. So far, MC4R-induced signaling has been exclusively attributed to its coupling to G(s) proteins. In line with this monogamous G protein coupling profile, most MC4R mutants isolated from obese individuals showed a reduced ability to activate G(s). However, some mutants displayed enhanced G(s) coupling, suggesting that signaling pathways independent of G(s) may be involved in MC4R-mediated anorexigenic signaling. Here we report that the G(s) signaling-deficient MC4R-D90N mutant activates G proteins in a pertussis toxin-sensitive manner, indicating that this mutant is able to selectively interact with G(i/o) proteins. Analyzing a hypothalamic cell line (GT1-7 cells), we observed activation of pertussis toxin-sensitive G proteins by the wild-type MC4R as well, reflecting multiple coupling of the MC4R to G(s) and G(i/o) proteins in an endogenous cell system. Surprisingly, the agouti-related protein, which has been classified as a MC4R antagonist, selectively activates G(i/o) signaling in GT1-7 cells. Thus, the agouti-related protein antagonizes melanocortin-dependent G(s) activation not only by competitive antagonism but additionally by initiating G(i/o) protein-induced signaling as a biased agonist.
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Affiliation(s)
- Thomas R H Büch
- Walther-Straub-Institut für Pharmakologie und Toxikologie, Ludwig-Maximilians-Universität München, 80336 München
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Mederos y Schnitzler M, Storch U, Meibers S, Nurwakagari P, Breit A, Essin K, Gollasch M, Gudermann T. Gq-coupled receptors as mechanosensors mediating myogenic vasoconstriction. EMBO J 2008; 27:3092-103. [PMID: 18987636 DOI: 10.1038/emboj.2008.233] [Citation(s) in RCA: 278] [Impact Index Per Article: 17.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2008] [Accepted: 10/13/2008] [Indexed: 02/06/2023] Open
Abstract
Despite the central physiological function of the myogenic response, the underlying signalling pathways and the identity of mechanosensors in vascular smooth muscle (VSM) are still elusive. In contrast to present thinking, we show that membrane stretch does not primarily gate mechanosensitive transient receptor potential (TRP) ion channels, but leads to agonist-independent activation of G(q/11)-coupled receptors, which subsequently signal to TRPC channels in a G protein- and phospholipase C-dependent manner. Mechanically activated receptors adopt an active conformation, allowing for productive G protein coupling and recruitment of beta-arrestin. Agonist-independent receptor activation by mechanical stimuli is blocked by specific antagonists and inverse agonists. Increasing the AT(1) angiotensin II receptor density in mechanically unresponsive rat aortic A7r5 cells resulted in mechanosensitivity. Myogenic tone of cerebral and renal arteries is profoundly diminished by the inverse angiotensin II AT(1) receptor agonist losartan independently of angiotensin II (AII) secretion. This inhibitory effect is enhanced in blood vessels of mice deficient in the regulator of G-protein signalling-2. These findings suggest that G(q/11)-coupled receptors function as sensors of membrane stretch in VSM cells.
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Büch TR, Biebermann H, Kalwa H, Pinkenburg O, Hager D, Barth H, Aktories K, Breit A, Gudermann T. G13-dependent Activation of MAPK by Thyrotropin. J Biol Chem 2008; 283:20330-41. [DOI: 10.1074/jbc.m800211200] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
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Pontier SM, Percherancier Y, Galandrin S, Breit A, Galés C, Bouvier M. Cholesterol-dependent separation of the beta2-adrenergic receptor from its partners determines signaling efficacy: insight into nanoscale organization of signal transduction. J Biol Chem 2008; 283:24659-72. [PMID: 18566454 DOI: 10.1074/jbc.m800778200] [Citation(s) in RCA: 111] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Determining the role of lipid raft nanodomains in G protein-coupled receptor signaling remains fraught by the lack of assays directly monitoring rafts in native membranes. We thus combined extensive biochemical and pharmacological approaches to a nanoscale strategy based on bioluminescence resonance energy transfer (BRET) to assess the spatial and functional influence of cholesterol-rich liquid-ordered lipid nanodomains on beta2 adrenergic receptor (beta2AR) signaling. The data revealed that whereas beta2AR did not partition within liquid-ordered lipid phase, a pool of G protein and adenylyl cyclase (AC) were sequestered in these domains. Destabilization of the liquid-ordered phase by cholesterol depletion led to a lateral redistribution of Galphas and AC that favored interactions between the receptor and its signaling partners as assessed by BRET. This resulted in an increased basal and agonist-promoted beta2AR-stimulated cAMP production that was partially dampened as a result of constitutive protein kinase A-dependent phosphorylation and desensitization of the receptor. This restraining influence of nanodomains on beta2AR signaling was further substantiated by showing that liquid-ordered lipid phase stabilization using caveolin overexpression or increasing membrane cholesterol amount led to an inhibition of beta2AR-associated signaling. Given the emerging concept that clustering of receptors and effectors into signaling platforms contributes to the efficacy and selectivity of signal transduction, our results support a model whereby cholesterol-promoted liquid-ordered lipid phase-embedding Gs and AC allows their lateral separation from the receptor, thus restraining the basal activity and controlling responsiveness of beta2AR signaling machinery within larger signaling platforms.
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Affiliation(s)
- Stéphanie M Pontier
- Institut de Recherche en Immunologie et Cancérologie, Département de Biochimie, Université de Montréal, Montréal, Québec H3C 3J7, Canada
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Schnitzler MMY, Storch U, Meibers S, Essin K, Breit A, Gollasch M, Gudermann T. Gq‐coupled vasopressor receptors are essential mechanosensitive components for the myogenic vasoconstriction. FASEB J 2008. [DOI: 10.1096/fasebj.22.1_supplement.737.5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
| | - Ursula Storch
- Philipps‐UniversityInstitute of PharmacologyMarburgGermany
| | - Simone Meibers
- Philipps‐UniversityInstitute of PharmacologyMarburgGermany
| | | | - Andreas Breit
- Philipps‐UniversityInstitute of PharmacologyMarburgGermany
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Nurwakagari P, Breit A, Hess C, Salman-Livny H, Ben-Menahem D, Gudermann T. A conformational contribution of the luteinizing hormone-receptor ectodomain to receptor activation. J Mol Endocrinol 2007; 38:259-75. [PMID: 17293445 DOI: 10.1677/jme.1.02160] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Glycoprotein hormone receptors such as the lutropin/chorionic gonadotropin receptor (LHR) are characterized by a large N-terminal ectodomain (ECD), which is responsible for hormone-receptor interactions. For the closely related TSH receptor (TSHR), it has been proposed that the ECD also serves as a tethered inverse agonist. However, the exact role of the LHR-ECD for receptor activation remains elusive. Functional analysis of N-terminally truncated LHR mutants expressed in COS-7 cells revealed that the LHR-ECD does not act as an inverse agonist but facilitates active LHR conformations. This notion is supported by two observations: first, removal of the ECD tended to decrease basal LHR activity and secondly, mutationally induced constitutive receptor activity was diminished for most activating mutations in LHR lacking the ECD. In addition, swapping of the LHR-ECD for the ECD of the closely related TSHR was not sufficient to restore constitutive receptor activity induced by naturally occurring activating heptahelical LHR mutations. Thus, the ECD stabilizes an activation-competent conformation of the heptahelical region. While the full-length LHR fused to the cognate agonist, human chorionic gonadotropin (hCG), showed increased basal activity, fusion proteins between hCG and N-terminally truncated LHR did not yield constitutive receptor activity suggesting an important role of the ECD also for agonist-dependent LHR activity. Our experiments strengthen the concept of a major contribution of the LHR-ECD in the activation mechanism apart from hormone binding and provide evidence for a cooperative model with structural and functional interactions of the ECD and the transmembrane domain.
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Affiliation(s)
- Pascal Nurwakagari
- Institut für Pharmakologie und Toxikologie, Philipps-Universität Marburg, Karl-von-Frisch-Strasse 1, 35033 Marburg, Germany
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Breit A, Wolff K, Kalwa H, Jarry H, Büch T, Gudermann T. The natural inverse agonist agouti-related protein induces arrestin-mediated endocytosis of melanocortin-3 and -4 receptors. J Biol Chem 2006; 281:37447-56. [PMID: 17041250 DOI: 10.1074/jbc.m605982200] [Citation(s) in RCA: 57] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Agouti-related protein (Agrp), one of the two naturally occurring inverse agonists known to inhibit G protein-coupled receptor activity, regulates energy expenditure by decreasing basal and blocking agonist-promoted melanocortin receptor (MCR) signaling. Here we report that, in addition to its inverse agonistic activities, Agrp exhibits agonistic properties on the endocytosis pathway of melanocortin receptors. Sustained exposure of human embryonic kidney 293 cells to Agrp induced endocytosis of the MC3R or the MC4R. The extent and kinetics of Agrp-promoted MCR endocytosis were similar to the endocytosis induced by melanocortins. Using the bioluminescence resonance energy transfer technique, we further showed that after binding of Agrp both MCRs interacted with beta-arrestins. In line with this observation, in COS-7 cells co-expression of beta-arrestins enhanced Agrp-induced MCR endocytosis, whereas in human embryonic kidney 293 cells co-transfection of beta-arrestin-specific small interference RNAs diminished Agrp-promoted endocytosis. This new regulatory mechanism was likewise detectable in a cell line derived from murine hypothalamic neurons endogenously expressing MC4R, pointing to the physiological relevance of Agrp-promoted receptor endocytosis. In conclusion, we demonstrated that Agrp does not solely act by directly blocking MCR signaling but also by reducing the amount of MCR molecules accessible to melanocortins at the cell surface. This beta-arrestin-dependent mechanism reveals a new aspect of MCR signaling in particular and refines the concept of G protein-coupled receptor antagonism in general.
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MESH Headings
- Agouti-Related Protein
- Animals
- Arrestins/antagonists & inhibitors
- Arrestins/genetics
- Arrestins/metabolism
- Base Sequence
- COS Cells
- Cell Line
- Chlorocebus aethiops
- Cyclic AMP/biosynthesis
- Endocytosis/physiology
- Humans
- Intercellular Signaling Peptides and Proteins/genetics
- Intercellular Signaling Peptides and Proteins/metabolism
- Mice
- Protein Binding
- RNA, Small Interfering/genetics
- Receptor, Melanocortin, Type 3/antagonists & inhibitors
- Receptor, Melanocortin, Type 3/genetics
- Receptor, Melanocortin, Type 3/metabolism
- Receptor, Melanocortin, Type 4/antagonists & inhibitors
- Receptor, Melanocortin, Type 4/genetics
- Receptor, Melanocortin, Type 4/metabolism
- Recombinant Fusion Proteins/antagonists & inhibitors
- Recombinant Fusion Proteins/genetics
- Recombinant Fusion Proteins/metabolism
- Signal Transduction
- Transfection
- beta-Arrestins
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Affiliation(s)
- Andreas Breit
- Institut für Pharmakologie und Toxikologie, Philipps-Universität Marburg, 35033 Marburg, Germany
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Breit A, Gagnidze K, Devi LA, Lagacé M, Bouvier M. Simultaneous activation of the delta opioid receptor (deltaOR)/sensory neuron-specific receptor-4 (SNSR-4) hetero-oligomer by the mixed bivalent agonist bovine adrenal medulla peptide 22 activates SNSR-4 but inhibits deltaOR signaling. Mol Pharmacol 2006; 70:686-96. [PMID: 16682504 DOI: 10.1124/mol.106.022897] [Citation(s) in RCA: 58] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Hetero-oligomerization among G protein-coupled receptors has been proposed to contribute to signal integration. Because sensory neuron-specific receptors (SNSRs) and the opioid receptors (OR) share a common ligand, the bovine adrenal medulla peptide (BAM) 22, and have opposite effects on pain modulation, we investigated the possible consequences of deltaOR/SNSR-4 hetero-oligomerization on the signaling properties of both receptor subtypes. Bioluminescence resonance energy transfer revealed that the human deltaOR has similar propensity to homo-oligomerize and to form hetero-oligomers with human SNSR-4 when coexpressed in human embryonic kidney 293 cells. The hetero-oligomerization leads to a receptor form displaying unique functional properties. Individual activation of either deltaOR or SNSR-4 in cells coexpressing the two receptors led to the modulation of their respective signaling pathways; inhibition of adenylyl cyclase and activation of phospholipase C, respectively. In contrast, the deltaOR/SNSR-4 bivalent agonist BAM22, which could activate each receptor expressed individually, fully activated the SNSR-4-dependent phospholipase C but did not promote deltaOR-mediated inhibition of adenylyl cyclase in deltaOR/SNSR-4-coexpressing cells. Likewise, concomitant activation of the deltaOR/SNSR-4 hetero-oligomer by selective deltaOR and SNSR-4 agonists promoted SNSR-4 but not deltaOR signaling, revealing an agonist-dependent dominant-negative effect of SNSR-4 on deltaOR signaling. Furthermore, the deltaOR selective antagonist naltrexone trans-inhibited the SNSR-4-promoted phospholipase C activation mediated by BAM22 but not by the SNSR-4-selective agonists, suggesting a bivalent binding mode of BAM22 to the deltaOR/SNSR-4 hetero-oligomer. The observation that BAM22 inhibited the Leu-enkephalin-promoted cAMP inhibition in rat dorsal root ganglia neurons supports the potential physiological implication of such regulatory mechanism.
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MESH Headings
- Adenylyl Cyclase Inhibitors
- Adenylyl Cyclases/metabolism
- Animals
- Cells, Cultured
- Endocytosis
- Enkephalin, Methionine/analogs & derivatives
- Enkephalin, Methionine/pharmacology
- Ganglia, Spinal/drug effects
- Humans
- Naltrexone/pharmacology
- Neurons, Afferent/metabolism
- Protein Kinase C/physiology
- Protein Precursors/pharmacology
- Rats
- Rats, Long-Evans
- Receptors, G-Protein-Coupled/chemistry
- Receptors, G-Protein-Coupled/drug effects
- Receptors, Opioid, delta/antagonists & inhibitors
- Receptors, Opioid, delta/chemistry
- Receptors, Opioid, delta/drug effects
- Receptors, Opioid, delta/metabolism
- Signal Transduction
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Affiliation(s)
- Andreas Breit
- Département de Biochimie, Université de Montréal, H3C 3J7 Montréal, QC, Canada
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Galés C, Rebois RV, Hogue M, Trieu P, Breit A, Hébert TE, Bouvier M. Real-time monitoring of receptor and G-protein interactions in living cells. Nat Methods 2005; 2:177-84. [PMID: 15782186 DOI: 10.1038/nmeth743] [Citation(s) in RCA: 315] [Impact Index Per Article: 16.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2004] [Accepted: 01/25/2005] [Indexed: 11/08/2022]
Abstract
G protein-coupled receptors (GPCRs) represent the largest family of proteins involved in signal transduction. Here we present a bioluminescence resonance energy transfer (BRET) assay that directly monitors in real time the early interactions between human GPCRs and their cognate G-protein subunits in living human cells. In addition to detecting basal precoupling of the receptors to Galpha-, Gbeta- and Ggamma-subunits, BRET measured very rapid ligand-induced increases in the interaction between receptor and Galphabetagamma-complexes (t(1/2) approximately 300 ms) followed by a slower (several minutes) decrease, reflecting receptor desensitization. The agonist-promoted increase in GPCR-Gbetagamma interaction was highly dependent on the identity of the Galpha-subunit present in the complex. Therefore, this G protein-activity biosensor provides a novel tool to directly probe the dynamics and selectivity of receptor-mediated, G-protein activation-deactivation cycles that could be advantageously used to identify ligands for orphan GPCRs.
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Affiliation(s)
- Céline Galés
- Department of Biochemistry, Université de Montréal, P.O. Box 6128 Down-town station, Montréal, H3C 3J7, Canada
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Breit A, Lagacé M, Bouvier M. Hetero-oligomerization between β2- and β3-Adrenergic Receptors Generates a β-Adrenergic Signaling Unit with Distinct Functional Properties. J Biol Chem 2004; 279:28756-65. [PMID: 15123695 DOI: 10.1074/jbc.m313310200] [Citation(s) in RCA: 119] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The ability of the closely related beta(2)- and beta(3)-adrenergic receptors (AR) to form hetero-oligomers was assessed by bioluminescence resonance energy transfer. Quantitative bioluminescence resonance energy transfer titration curves revealed that the beta(2)AR has identical propensity to hetero-oligomerize with the beta(3)AR than to form homo-oligomers. To determine the influence of heterooligomerization, a HEK293 cell line stably expressing an excess of beta(3)AR over beta(2)AR was generated so that all beta(2)AR are engaged in hetero-oligomerization with beta(3)AR, providing a tool to study the effect of hetero-oligomerization on beta(2)AR function in the absence of any beta(2)AR homooligomer. The hetero-oligomerization had no effect on the ligand binding properties of various beta(2)AR ligands and did not affect the potency of isoproterenol to stimulate adenylyl cyclase. Despite the unaltered ligand binding properties of the beta(2/3)AR hetero-oligomer, the stable association of the beta(2)AR with the beta(3)AR completely blocked agonist-stimulated internalization of the beta(2)AR. Given that the beta(3)AR is resistant to agonist-promoted endocytosis, the results indicate that the beta(3)AR acted as a dominant negative of the beta(2)AR endocytosis process. Consistent with this notion, the beta(2/3)AR hetero-oligomer displayed a lower propensity to recruit beta-arrestin-2 than the beta(2)AR. The hetero-oligomerization also led to a change in G protein coupling selectivity. Indeed, in contrast to beta(2)AR and beta(3)AR, which regulate adenylyl cyclase and extracellular signal-regulated kinase activity through a coupling to G(s) and G(i/o), no G(i/o) coupling was observed for the beta(2/3)AR hetero-oligomer. Together, these results demonstrate that hetero-oligomerization between beta(2)AR and beta(3)AR forms a beta-adrenergic signaling unit that possesses unique functional properties.
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MESH Headings
- Adenylyl Cyclases/metabolism
- Animals
- COS Cells
- Cell Line
- Cell Membrane/metabolism
- Cyclic AMP/metabolism
- Dimerization
- Dose-Response Relationship, Drug
- Endocytosis
- Fluorescence Resonance Energy Transfer
- Genes, Dominant
- Genetic Vectors
- Humans
- Kinetics
- Ligands
- Mitogen-Activated Protein Kinase 1/metabolism
- Mitogen-Activated Protein Kinase 3
- Mitogen-Activated Protein Kinases/metabolism
- Pertussis Toxin/pharmacology
- Protein Binding
- Protein Structure, Tertiary
- Receptors, Adrenergic, beta-2/chemistry
- Receptors, Adrenergic, beta-2/metabolism
- Receptors, Adrenergic, beta-3/chemistry
- Receptors, Adrenergic, beta-3/metabolism
- Signal Transduction
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Affiliation(s)
- Andreas Breit
- Département de Biochimie et Groupe de Recherche sur le Système Nerveux Autonome, Université de Montréal, Montréal, Québec H3C 3J7, Canada
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Schroeder C, Breit A, Böning H, Dedio J, Gera L, Stewart J, Müller-Esterl W. Changes in amino-terminal portion of human B2 receptor selectively increase efficacy of synthetic ligand HOE 140 but not of cognate ligand bradykinin. Am J Physiol Heart Circ Physiol 2003; 284:H1924-32. [PMID: 12574004 DOI: 10.1152/ajpheart.00033.2003] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Recently, we have shown that a widely used antagonist of the human bradykinin B(2) receptor (B(2)R) HOE 140 acts as a full agonist of the chicken ornithokinin receptor (B(o)R). To understand the molecular mechanisms underlying differential efficacy of HOE 140 for the various kinin receptors, we have constructed chimeric kinin receptors (CKR) in which the amino-terminal portion including the first two transmembrane regions and the first extracellular loop (CKR-2) or only the second transmembrane region and the first extracellular loop (CKR-1) of B(2)R were substituted with the corresponding segments of B(o)R. Ligand efficacy of synthetic ligand HOE 140 decreased in the order B(o)R > CKR-2 > CKR-1 > B(2)R, whereas the efficacy of the endogenous kinin ligand was unchanged. Enhanced HOE 140 efficacy was not due to a structural change in the ligand binding site or to an enhanced receptor expression level. Rather, heterologous binding competition studies indicated that structural change(s) introduced into the engineered receptors caused a selective reduction in apparent affinity of HOE 140 for the uncoupled inactive receptor state R but not for the active G protein-coupled state R*, thereby increasing the ratio of R* over R for a given ligand concentration. Our results may help explain the unusually broad efficacy spectrum of HOE 140, which varies from inverse to full agonism, depending on kinin receptor subtype, tissue origin, or species.
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Affiliation(s)
- Christian Schroeder
- Institute for Cardiovascular and Arteriosclerosis Research, Bayer D-42096, Wuppertal, Germany
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