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Hausmann M, Seuwen K, de Vallière C, Busch M, Ruiz PA, Rogler G. Role of pH-sensing receptors in colitis. Pflugers Arch 2024; 476:611-622. [PMID: 38514581 PMCID: PMC11006753 DOI: 10.1007/s00424-024-02943-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2023] [Revised: 03/06/2024] [Accepted: 03/06/2024] [Indexed: 03/23/2024]
Abstract
Low pH in the gut is associated with severe inflammation, fibrosis, and colorectal cancer (CRC) and is a hallmark of active inflammatory bowel disease (IBD). Subsequently, pH-sensing mechanisms are of interest for the understanding of IBD pathophysiology. Tissue hypoxia and acidosis-two contributing factors to disease pathophysiology-are linked to IBD, and understanding their interplay is highly relevant for the development of new therapeutic options. One member of the proton-sensing G protein-coupled receptor (GPCR) family, GPR65 (T-cell death-associated gene 8, TDAG8), was identified as a susceptibility gene for IBD in a large genome-wide association study. In response to acidic extracellular pH, GPR65 induces an anti-inflammatory response, whereas the two other proton-sensing receptors, GPR4 and GPR68 (ovarian cancer G protein-coupled receptor 1, OGR1), mediate pro-inflammatory responses. Here, we review the current knowledge on the role of these proton-sensing receptors in IBD and IBD-associated fibrosis and cancer, as well as colitis-associated cancer (CAC). We also describe emerging small molecule modulators of these receptors as therapeutic opportunities for the treatment of IBD.
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Affiliation(s)
- Martin Hausmann
- Department of Gastroenterology and Hepatology, University Hospital Zurich, University of Zurich, 8091, Zurich, CH, Switzerland.
| | - Klaus Seuwen
- Department of Gastroenterology and Hepatology, University Hospital Zurich, University of Zurich, 8091, Zurich, CH, Switzerland
| | - Cheryl de Vallière
- Department of Gastroenterology and Hepatology, University Hospital Zurich, University of Zurich, 8091, Zurich, CH, Switzerland
| | - Moana Busch
- Department of Gastroenterology and Hepatology, University Hospital Zurich, University of Zurich, 8091, Zurich, CH, Switzerland
| | - Pedro A Ruiz
- Department of Gastroenterology and Hepatology, University Hospital Zurich, University of Zurich, 8091, Zurich, CH, Switzerland
| | - Gerhard Rogler
- Department of Gastroenterology and Hepatology, University Hospital Zurich, University of Zurich, 8091, Zurich, CH, Switzerland
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2
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Ji R, Chang L, An C, Zhang J. Proton-sensing ion channels, GPCRs and calcium signaling regulated by them: implications for cancer. Front Cell Dev Biol 2024; 12:1326231. [PMID: 38505262 PMCID: PMC10949864 DOI: 10.3389/fcell.2024.1326231] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2023] [Accepted: 02/14/2024] [Indexed: 03/21/2024] Open
Abstract
Extracellular acidification of tumors is common. Through proton-sensing ion channels or proton-sensing G protein-coupled receptors (GPCRs), tumor cells sense extracellular acidification to stimulate a variety of intracellular signaling pathways including the calcium signaling, which consequently exerts global impacts on tumor cells. Proton-sensing ion channels, and proton-sensing GPCRs have natural advantages as drug targets of anticancer therapy. However, they and the calcium signaling regulated by them attracted limited attention as potential targets of anticancer drugs. In the present review, we discuss the progress in studies on proton-sensing ion channels, and proton-sensing GPCRs, especially emphasizing the effects of calcium signaling activated by them on the characteristics of tumors, including proliferation, migration, invasion, metastasis, drug resistance, angiogenesis. In addition, we review the drugs targeting proton-sensing channels or GPCRs that are currently in clinical trials, as well as the relevant potential drugs for cancer treatments, and discuss their future prospects. The present review aims to elucidate the important role of proton-sensing ion channels, GPCRs and calcium signaling regulated by them in cancer initiation and development. This review will promote the development of drugs targeting proton-sensing channels or GPCRs for cancer treatments, effectively taking their unique advantage as anti-cancer drug targets.
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Affiliation(s)
- Renhui Ji
- Foundational and Translational Medical Research Center, Department of Allergy and General Surgery, Hohhot First Hospital, Hohhot, China
- Department of Pathophysiology, Basic Medicine College of Inner Mongolia Medical University, Hohhot, China
| | - Li Chang
- Foundational and Translational Medical Research Center, Department of Allergy and General Surgery, Hohhot First Hospital, Hohhot, China
- Department of Pathophysiology, Basic Medicine College of Inner Mongolia Medical University, Hohhot, China
| | - Caiyan An
- Foundational and Translational Medical Research Center, Department of Allergy and General Surgery, Hohhot First Hospital, Hohhot, China
| | - Junjing Zhang
- Foundational and Translational Medical Research Center, Department of Allergy and General Surgery, Hohhot First Hospital, Hohhot, China
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3
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Perren L, Busch M, Schuler C, Ruiz PA, Foti F, Weibel N, de Vallière C, Morsy Y, Seuwen K, Hausmann M, Rogler G. OGR1 (GPR68) and TDAG8 (GPR65) Have Antagonistic Effects in Models of Colonic Inflammation. Int J Mol Sci 2023; 24:14855. [PMID: 37834303 PMCID: PMC10573511 DOI: 10.3390/ijms241914855] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2023] [Revised: 09/29/2023] [Accepted: 09/29/2023] [Indexed: 10/15/2023] Open
Abstract
G-protein-coupled receptors (GPRs), including pro-inflammatory ovarian cancer GPR1 (OGR1/GPR68) and anti-inflammatory T cell death-associated gene 8 (TDAG8/GPR65), are involved in pH sensing and linked to inflammatory bowel disease (IBD). OGR1 and TDAG8 show opposite effects. To determine which effect is predominant or physiologically more relevant, we deleted both receptors in models of intestinal inflammation. Combined Ogr1 and Tdag8 deficiency was assessed in spontaneous and acute murine colitis models. Disease severity was assessed using clinical scores. Colon samples were analyzed using quantitative polymerase chain reaction (qPCR) and flow cytometry (FACS). In acute colitis, Ogr1-deficient mice showed significantly decreased clinical scores compared with wildtype (WT) mice, while Tdag8-deficient mice and double knockout (KO) mice presented similar scores to WT. In Il-10-spontaneous colitis, Ogr1-deficient mice presented significantly decreased, and Tdag8-deficient mice had increased inflammation. In the Il10-/- × Ogr1-/- × Tdag8-/- triple KO mice, inflammation was significantly decreased compared with Tdag8-/-. Absence of Ogr1 reduced pro-inflammatory cytokines in Tdag8-deficient mice. Tdag8-/- had significantly more IFNγ+ T-lymphocytes and IL-23 T-helper cells in the colon compared with WT. The absence of OGR1 significantly alleviates the intestinal damage mediated by the lack of functional TDAG8. Both OGR1 and TDAG8 represent potential new targets for therapeutic intervention.
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4
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Chamniansawat S, Suksridechacin N, Thongon N. Current opinion on the regulation of small intestinal magnesium absorption. World J Gastroenterol 2023; 29:332-342. [PMID: 36687126 PMCID: PMC9846944 DOI: 10.3748/wjg.v29.i2.332] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/13/2022] [Revised: 10/25/2022] [Accepted: 11/19/2022] [Indexed: 01/06/2023] Open
Abstract
Magnesium (Mg2+) has an important role in numerous biological functions, and Mg2+ deficiency is associated with several diseases. Therefore, adequate intestinal absorption of Mg2+ is vital for health. The small intestine was previously thought to absorb digested Mg2+ exclusively through an unregulated paracellular mechanism, which is responsible for approximately 90% of total Mg2+ absorption. Recent studies, however, have revealed that the duodenum, jejunum, and ileum absorb Mg2+ through both transcellular and paracellular routes. Several regulatory factors of small intestinal Mg2+ uptake also have been explored, e.g., parathyroid hormone, fibroblast growth factor-23, apical acidity, proton pump inhibitor, and pH-sensing channel and receptors. The mechanistic factors underlying proton pump inhibitor suppression of small intestinal Mg2+, such as magnesiotropic protein dysfunction, higher mucosal bicarbonate secretion, Paneth cell dysfunction, and intestinal inflammation, are currently being explored. The potential role of small intestinal microbiomes in Mg2+ absorption has also been proposed. In this article, we reviewed the current knowledge on the mechanisms and regulatory factors of small intestinal Mg2+ absorption.
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Affiliation(s)
- Siriporn Chamniansawat
- Division of Anatomy, Department of Medical Sciences, Faculty of Allied Health Sciences, Burapha University, Muang 20131, Chonburi, Thailand
| | - Nasisorn Suksridechacin
- Biodiversity Research Centre, Thailand Institute of Scientific and Technological Research, Khlong Luang 12120, Pathum Thani, Thailand
| | - Narongrit Thongon
- Division of Physiology, Department of Medical Sciences, Faculty of Allied Health Sciences, Burapha University, Muang 20131, Chonburi, Thailand
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5
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van Setten GB. GPR-68 in human lacrimal gland. Detection and possible role in the pathogenesis of dry eye disease. J Fr Ophtalmol 2022; 45:921-927. [DOI: 10.1016/j.jfo.2022.02.009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2022] [Revised: 01/25/2022] [Accepted: 02/01/2022] [Indexed: 11/16/2022]
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Nagel DJ, Rackow AR, Ku WY, Bell TJ, Sime PJ, Kottmann RM. Cell-Type-Specific Effects of the Ovarian Cancer G-Protein Coupled Receptor (OGR1) on Inflammation and Fibrosis; Potential Implications for Idiopathic Pulmonary Fibrosis. Cells 2022; 11:2540. [PMID: 36010617 PMCID: PMC9406836 DOI: 10.3390/cells11162540] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2022] [Revised: 08/08/2022] [Accepted: 08/09/2022] [Indexed: 11/16/2022] Open
Abstract
Idiopathic pulmonary fibrosis (IPF) is a disease characterized by irreversible lung scarring. The pathophysiology is not fully understood, but the working hypothesis postulates that a combination of epithelial injury and myofibroblast differentiation drives progressive pulmonary fibrosis. We previously demonstrated that a reduction in extracellular pH activates latent TGF-β1, and that TGF-β1 then drives its own activation, creating a feed-forward mechanism that propagates myofibroblast differentiation. Given the important roles of extracellular pH in the progression of pulmonary fibrosis, we sought to identify whether pH mediates other cellular phenotypes independent of TGF-β1. Proton-sensing G-protein coupled receptors are activated by acidic environments, but their role in fibrosis has not been studied. Here, we report that the Ovarian Cancer G-Protein Coupled Receptor1 (OGR1 or GPR68) has dual roles in both promoting and mitigating pulmonary fibrosis. We demonstrate that OGR1 protein expression is significantly reduced in lung tissue from patients with IPF and that TGF-β1 decreases OGR1 expression. In fibroblasts, OGR1 inhibits myofibroblast differentiation and does not contribute to inflammation. However, in epithelial cells, OGR1 promotes epithelial to mesenchymal transition (EMT) and inflammation. We then demonstrate that sub-cellular localization and alternative signaling pathways may be responsible for the differential effect of OGR1 in each cell type. Our results suggest that strategies to selectively target OGR1 expression may represent a novel therapeutic strategy for pulmonary fibrosis.
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Affiliation(s)
- David J. Nagel
- Department of Medicine, Division of Pulmonary and Critical Care Medicine, University of Rochester Medical Center, Rochester, NY 14642, USA
| | - Ashley R. Rackow
- Laboratory Medicine, Department of Pathology, Division of Clinical Chemistry, Johns Hopkins University, Baltimore, MD 21287, USA
| | - Wei-Yao Ku
- BMW of North America, Woodcliff Lake, NJ 07675, USA
| | - Tyler J. Bell
- Department of Environmental Medicine, School of Medicine and Dentistry, University of Rochester, Rochester, NY 14642, USA
| | - Patricia J. Sime
- Department of Medicine, Virginia Commonwealth University Health System, Richmond, VA 23298, USA
| | - Robert Matthew Kottmann
- Department of Medicine, Division of Pulmonary and Critical Care Medicine, University of Rochester Medical Center, Rochester, NY 14642, USA
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7
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Chiba Y, Yamane Y, Sato T, Suto W, Hanazaki M, Sakai H. Hyperresponsiveness to Extracellular Acidification-Mediated Contraction in Isolated Bronchial Smooth Muscles of Murine Experimental Asthma. Lung 2022; 200:591-599. [PMID: 35930050 DOI: 10.1007/s00408-022-00558-7] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2022] [Accepted: 07/21/2022] [Indexed: 11/30/2022]
Abstract
PURPOSE Extracellular acidification is a major component of tissue inflammation, including airway inflammation. The extracellular proton-sensing mechanisms are inherent in various cells including airway structural cells, although their physiological and pathophysiological roles in bronchial smooth muscles (BSMs) are not fully understood. In the present study, to explore the functional role of extracellular acidification on the BSM contraction, the isolated mouse BSMs were exposed to acidic pH under contractile stimulation. METHODS AND RESULTS The RT-PCR analyses revealed that the proton-sensing G protein-coupled receptors were expressed both in mouse BSMs and cultured human BSM cells. In the mouse BSMs, change in the extracellular pH from 8.0 to 6.8 caused an augmentation of contraction induced by acetylcholine. Interestingly, the acidic pH-induced BSM hyper-contraction was further augmented in the mice that were sensitized and repeatedly challenged with ovalbumin antigen. In this animal model of asthma, upregulations of G protein-coupled receptor 68 (GPR68) and GPR65, that were believed to be coupled with Gq and Gs proteins respectively, were observed, indicating that the acidic pH could cause hyper-contraction probably via an activation of GPR68. However, psychosine, a putative antagonist for GPR68, failed to block the acidic pH-induced responses. CONCLUSION These findings suggest that extracellular acidification contributes to the airway hyperresponsiveness, a characteristic feature of bronchial asthma. Further studies are required to identify the receptor(s) responsible for sensing extracellular protons in BSM cells.
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Affiliation(s)
- Yoshihiko Chiba
- Laboratory of Molecular Biology and Physiology, Hoshi University School of Pharmacy, 2-4-41 Ebara, Shinagawa-ku, Tokyo, 142-8501, Japan.
| | - Yamato Yamane
- Laboratory of Molecular Biology and Physiology, Hoshi University School of Pharmacy, 2-4-41 Ebara, Shinagawa-ku, Tokyo, 142-8501, Japan
| | - Tsubasa Sato
- Laboratory of Molecular Biology and Physiology, Hoshi University School of Pharmacy, 2-4-41 Ebara, Shinagawa-ku, Tokyo, 142-8501, Japan
| | - Wataru Suto
- Laboratory of Molecular Biology and Physiology, Hoshi University School of Pharmacy, 2-4-41 Ebara, Shinagawa-ku, Tokyo, 142-8501, Japan
| | - Motohiko Hanazaki
- Department of Anesthesiology and Intensive Care Medicine, School of Medicine, International University of Health and Welfare, Narita, Japan
| | - Hiroyasu Sakai
- Laboratory of Biomolecular Pharmacology, Hoshi University School of Pharmacy, Tokyo, Japan
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8
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'Warburg effect' controls tumor growth, bacterial, viral infections and immunity - Genetic deconstruction and therapeutic perspectives. Semin Cancer Biol 2022; 86:334-346. [PMID: 35820598 DOI: 10.1016/j.semcancer.2022.07.004] [Citation(s) in RCA: 40] [Impact Index Per Article: 20.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2022] [Revised: 07/06/2022] [Accepted: 07/07/2022] [Indexed: 12/16/2022]
Abstract
The evolutionary pressure for life transitioning from extended periods of hypoxia to an increasingly oxygenated atmosphere initiated drastic selections for a variety of biochemical pathways supporting the robust life currently present on the planet. First, we discuss how fermentative glycolysis, a primitive metabolic pathway present at the emergence of life, is instrumental for the rapid growth of cancer, regenerating tissues, immune cells but also bacteria and viruses during infections. The 'Warburg effect', activated via Myc and HIF-1 in response to growth factors and hypoxia, is an essential metabolic and energetic pathway which satisfies nutritional and energetic demands required for rapid genome replication. Second, we present the key role of lactic acid, the end-product of fermentative glycolysis able to move across cell membranes in both directions via monocarboxylate transporting proteins (i.e. MCT1/4) contributing to cell-pH homeostasis but also to the complex immune response via acidosis of the tumour microenvironment. Importantly lactate is recycled in multiple organs as a major metabolic precursor of gluconeogenesis and energy source protecting cells and animals from harsh nutritional or oxygen restrictions. Third, we revisit the Warburg effect via CRISPR-Cas9 disruption of glucose-6-phosphate isomerase (GPI-KO) or lactate dehydrogenases (LDHA/B-DKO) in two aggressive tumours (melanoma B16-F10, human adenocarcinoma LS174T). Full suppression of lactic acid production reduces but does not suppress tumour growth due to reactivation of OXPHOS. In contrast, disruption of the lactic acid transporters MCT1/4 suppressed glycolysis, mTORC1, and tumour growth as a result of intracellular acidosis. Finally, we briefly discuss the current clinical developments of an MCT1 specific drug AZ3965, and the recent progress for a specific in vivo MCT4 inhibitor, two drugs of very high potential for future cancer clinical applications.
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9
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Pillai S, Mahmud I, Mahar R, Griffith C, Langsen M, Nguyen J, Wojtkowiak JW, Swietach P, Gatenby RA, Bui MM, Merritt ME, McDonald P, Garrett TJ, Gillies RJ. Lipogenesis mediated by OGR1 regulates metabolic adaptation to acid stress in cancer cells via autophagy. Cell Rep 2022; 39:110796. [PMID: 35545051 PMCID: PMC9137419 DOI: 10.1016/j.celrep.2022.110796] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2021] [Revised: 03/03/2022] [Accepted: 04/15/2022] [Indexed: 12/12/2022] Open
Abstract
Malignant tumors exhibit altered metabolism resulting in a highly acidic extracellular microenvironment. Here, we show that cytoplasmic lipid droplet (LD) accumulation, indicative of a lipogenic phenotype, is a cellular adaption to extracellular acidity. LD marker PLIN2 is strongly associated with poor overall survival in breast cancer patients. Acid-induced LD accumulation is triggered by activation of the acid-sensing G-protein-coupled receptor (GPCR) OGR1, which is expressed highly in breast tumors. OGR1 depletion inhibits acid-induced lipid accumulation, while activation by a synthetic agonist triggers LD formation. Inhibition of OGR1 downstream signaling abrogates the lipogenic phenotype, which can be rescued with OGR1 ectopic expression. OGR1-depleted cells show growth inhibition under acidic growth conditions in vitro and tumor formation in vivo. Isotope tracing shows that the source of lipid precursors is primarily autophagy-derived ketogenic amino acids. OGR1-depleted cells are defective in endoplasmic reticulum stress response and autophagy and hence fail to accumulate LDs affecting survival under acidic stress.
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Affiliation(s)
- Smitha Pillai
- Department of Cancer Physiology, H. Lee Moffitt Cancer Center and Research Institute, Tampa, FL, USA.
| | - Iqbal Mahmud
- Department of Pathology, Immunology and Laboratory Medicine, University of Florida, Gainesville, FL, USA
| | - Rohit Mahar
- Department of Biochemistry and Molecular Biology, University of Florida, Gainesville, FL, USA
| | - Crystal Griffith
- Department of Cancer Physiology, H. Lee Moffitt Cancer Center and Research Institute, Tampa, FL, USA
| | - Michael Langsen
- Department of Cancer Physiology, H. Lee Moffitt Cancer Center and Research Institute, Tampa, FL, USA
| | - Jonathan Nguyen
- Analytical Microscopy Core, H. Lee Moffitt Cancer Center and Research Institute, Tampa, FL, USA
| | - Jonathan W Wojtkowiak
- Department of Cancer Physiology, H. Lee Moffitt Cancer Center and Research Institute, Tampa, FL, USA
| | - Pawel Swietach
- Department of Physiology, Anatomy and Genetics Parks Road, Oxford OX1 3PT, UK
| | - Robert A Gatenby
- Department of Cancer Physiology, H. Lee Moffitt Cancer Center and Research Institute, Tampa, FL, USA; Department of Radiology, H. Lee Moffitt Cancer Center and Research Institute, Tampa, FL, USA
| | - Marilyn M Bui
- Analytical Microscopy Core, H. Lee Moffitt Cancer Center and Research Institute, Tampa, FL, USA; Department of Pathology, Moffitt Cancer Center and Research Institute, Tampa, FL, USA
| | - Matthew E Merritt
- Department of Biochemistry and Molecular Biology, University of Florida, Gainesville, FL, USA
| | - Patricia McDonald
- Department of Cancer Physiology, H. Lee Moffitt Cancer Center and Research Institute, Tampa, FL, USA
| | - Timothy J Garrett
- Department of Pathology, Immunology and Laboratory Medicine, University of Florida, Gainesville, FL, USA
| | - Robert J Gillies
- Department of Cancer Physiology, H. Lee Moffitt Cancer Center and Research Institute, Tampa, FL, USA; Department of Radiology, H. Lee Moffitt Cancer Center and Research Institute, Tampa, FL, USA
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10
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Feng Z, Sun R, Cong Y, Liu Z. Critical roles of G protein-coupled receptors in regulating intestinal homeostasis and inflammatory bowel disease. Mucosal Immunol 2022; 15:819-828. [PMID: 35732818 DOI: 10.1038/s41385-022-00538-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2022] [Revised: 05/29/2022] [Accepted: 06/05/2022] [Indexed: 02/04/2023]
Abstract
G protein-coupled receptors (GPCRs) are a group of membrane proteins that mediate most of the physiological responses to various signaling molecules such as hormones, neurotransmitters, and environmental stimulants. Inflammatory bowel disease (IBD) is a chronic relapsing disorder of the gastrointestinal tract and presents a spectrum of heterogeneous disorders falling under two main clinical subtypes including Crohn's disease (CD) and ulcerative colitis (UC). The pathogenesis of IBD is multifactorial and is related to a genetically dysregulated mucosal immune response to environmental drivers, mainly microbiotas. Although many drugs, such as 5-aminosalicylic acid, glucocorticoids, immunosuppressants, and biological agents, have been approved for IBD treatment, none can cure IBD permanently. Emerging evidence indicates significant associations between GPCRs and the pathogenesis of IBD. Here, we provide an overview of the essential physiological functions and signaling pathways of GPCRs and their roles in mucosal immunity and IBD regulation.
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Affiliation(s)
- Zhongsheng Feng
- Center for Inflammatory Bowel Disease Research, Department of Gastroenterology, The Shanghai Tenth People's Hospital, Tongji University School of Medicine, Shanghai, 200072, China
| | - Ruicong Sun
- Center for Inflammatory Bowel Disease Research, Department of Gastroenterology, The Shanghai Tenth People's Hospital, Tongji University School of Medicine, Shanghai, 200072, China
| | - Yingzi Cong
- Department of Microbiology and Immunology, University of Texas Medical Branch, Galveston, TX, 77555, USA
| | - Zhanju Liu
- Center for Inflammatory Bowel Disease Research, Department of Gastroenterology, The Shanghai Tenth People's Hospital, Tongji University School of Medicine, Shanghai, 200072, China.
- Department of Gastroenterology, the Second Affiliated Hospital of Zhengzhou University, Zhengzhou, 450014, China.
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11
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Lin R, Wu W, Chen H, Gao H, Wu X, Li G, He Q, Lu H, Sun M, Liu Z. GPR65 promotes intestinal mucosal Th1 and Th17 cell differentiation and gut inflammation through downregulating NUAK2. Clin Transl Med 2022; 12:e771. [PMID: 35343079 PMCID: PMC8958354 DOI: 10.1002/ctm2.771] [Citation(s) in RCA: 18] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2021] [Revised: 02/27/2022] [Accepted: 03/02/2022] [Indexed: 01/15/2023] Open
Abstract
G protein-coupled receptor 65 (GPR65), a susceptibility gene for inflammatory bowel diseases (IBD), has been identified to promote Th17 cell pathogenicity and induce T cell apoptosis. However, the potential role of GPR65 in modulating CD4+ T cell immune responses in the pathogenesis of IBD stills not entirely understood. Here, we displayed that GPR65 expression was increased in inflamed intestinal mucosa of IBD patients and positively associated with disease activity. It was expressed in CD4+ T cells and robustly upregulated through the TNF-α-caspase 3/8 signalling pathway. Ectopic expression of GPR65 significantly promoted the differentiation of peripheral blood (PB) CD4+ T cells from IBD patients and HC to Th1 and Th17 cells in vitro. Importantly, conditional knockout of Gpr65 in CD4+ T cells ameliorated trinitrobenzene sulfonic acid (TNBS)-induced acute murine colitis and a chronic colitis in Rag1-/- mice reconstituted with CD45RBhigh CD4+ T cells in vivo, characterised by attenuated Th1 and Th17 cell immune response in colon mucosa and decreased infiltration of CD4+ T cells, neutrophils and macrophages. RNA-seq analysis of Gpr65ΔCD4 and Gpr65flx/flx CD4+ T cells revealed that NUAK family kinase 2 (Nuak2) acts as a functional target of Gpr65 to restrict Th1 and Th17 cell immune response. Mechanistically, GPR65 deficiency promoted NUAK2 expression via the cAMP-PKA-C-Raf-ERK1/2-LKB1-mediated signalling pathway. Consistently, silencing of Nuak2 facilitated the differentiation of Gpr65ΔCD4 and Gpr65flx/flx CD4+ T cells into Th1 and Th17 cells. Therefore, our data point out that GPR65 promotes Th1 and Th17 cell immune response and intestinal mucosal inflammation by suppressing NUAK2 expression, and that targeting GPR65 and NUAK2 in CD4+ T cells may represent a novel therapeutic approach for IBD.
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Affiliation(s)
- Ritian Lin
- Center for Inflammatory Bowel Disease ResearchThe Shanghai Tenth People's HospitalTongji University of School MedicineShanghaiChina
| | - Wei Wu
- Center for Inflammatory Bowel Disease ResearchThe Shanghai Tenth People's HospitalTongji University of School MedicineShanghaiChina
| | - Huimin Chen
- Center for Inflammatory Bowel Disease ResearchThe Shanghai Tenth People's HospitalTongji University of School MedicineShanghaiChina
| | - Han Gao
- Center for Inflammatory Bowel Disease ResearchThe Shanghai Tenth People's HospitalTongji University of School MedicineShanghaiChina
| | - Xiaohan Wu
- Center for Inflammatory Bowel Disease ResearchThe Shanghai Tenth People's HospitalTongji University of School MedicineShanghaiChina
| | - Gengfeng Li
- Center for Inflammatory Bowel Disease ResearchThe Shanghai Tenth People's HospitalTongji University of School MedicineShanghaiChina
| | - Qiong He
- Center for Inflammatory Bowel Disease ResearchThe Shanghai Tenth People's HospitalTongji University of School MedicineShanghaiChina
| | - Huiying Lu
- Center for Inflammatory Bowel Disease ResearchThe Shanghai Tenth People's HospitalTongji University of School MedicineShanghaiChina
| | - Mingming Sun
- Center for Inflammatory Bowel Disease ResearchThe Shanghai Tenth People's HospitalTongji University of School MedicineShanghaiChina
| | - Zhanju Liu
- Center for Inflammatory Bowel Disease ResearchThe Shanghai Tenth People's HospitalTongji University of School MedicineShanghaiChina
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12
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de Vallière C, Cosin-Roger J, Baebler K, Schoepflin A, Mamie C, Mollet M, Schuler C, Bengs S, Lang S, Scharl M, Seuwen K, Ruiz PA, Hausmann M, Rogler G. pH-Sensing G Protein-Coupled Receptor OGR1 (GPR68) Expression and Activation Increases in Intestinal Inflammation and Fibrosis. Int J Mol Sci 2022; 23:ijms23031419. [PMID: 35163345 PMCID: PMC8835966 DOI: 10.3390/ijms23031419] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2021] [Revised: 01/14/2022] [Accepted: 01/17/2022] [Indexed: 12/14/2022] Open
Abstract
Local extracellular acidification occurs at sites of inflammation. Proton-sensing ovarian cancer G-protein-coupled receptor 1 (OGR1, also known as GPR68) responds to decreases in extracellular pH. Our previous studies show a role for OGR1 in the pathogenesis of mucosal inflammation, suggesting a link between tissue pH and immune responses. Additionally, pH-dependent signalling is associated with the progression of intestinal fibrosis. In this study, we aimed to investigate OGR1 expression and OGR1-mediated signalling in patients with inflammatory bowel disease (IBD). Our results show that OGR1 expression significantly increased in patients with IBD compared to non-IBD patients, as demonstrated by qPCR and immunohistochemistry (IHC). Paired samples from non-inflamed and inflamed intestinal areas of IBD patients showed stronger OGR1 IHC staining in inflamed mucosal segments compared to non-inflamed mucosa. IHC of human surgical samples revealed OGR1 expression in macrophages, granulocytes, endothelial cells, and fibroblasts. OGR1-dependent inositol phosphate (IP) production was significantly increased in CD14+ monocytes from IBD patients compared to healthy subjects. Primary human and murine fibroblasts exhibited OGR1-dependent IP formation, RhoA activation, F-actin, and stress fibre formation upon an acidic pH shift. OGR1 expression and signalling increases with IBD disease activity, suggesting an active role of OGR1 in the pathogenesis of IBD.
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Affiliation(s)
- Cheryl de Vallière
- Department of Gastroenterology and Hepatology, University Hospital Zurich, University of Zurich, 8091 Zurich, Switzerland; (C.d.V.); (J.C.-R.); (K.B.); (C.M.); (M.M.); (C.S.); (S.B.); (S.L.); (M.S.); (P.A.R.); (M.H.)
| | - Jesus Cosin-Roger
- Department of Gastroenterology and Hepatology, University Hospital Zurich, University of Zurich, 8091 Zurich, Switzerland; (C.d.V.); (J.C.-R.); (K.B.); (C.M.); (M.M.); (C.S.); (S.B.); (S.L.); (M.S.); (P.A.R.); (M.H.)
| | - Katharina Baebler
- Department of Gastroenterology and Hepatology, University Hospital Zurich, University of Zurich, 8091 Zurich, Switzerland; (C.d.V.); (J.C.-R.); (K.B.); (C.M.); (M.M.); (C.S.); (S.B.); (S.L.); (M.S.); (P.A.R.); (M.H.)
| | | | - Céline Mamie
- Department of Gastroenterology and Hepatology, University Hospital Zurich, University of Zurich, 8091 Zurich, Switzerland; (C.d.V.); (J.C.-R.); (K.B.); (C.M.); (M.M.); (C.S.); (S.B.); (S.L.); (M.S.); (P.A.R.); (M.H.)
| | - Michelle Mollet
- Department of Gastroenterology and Hepatology, University Hospital Zurich, University of Zurich, 8091 Zurich, Switzerland; (C.d.V.); (J.C.-R.); (K.B.); (C.M.); (M.M.); (C.S.); (S.B.); (S.L.); (M.S.); (P.A.R.); (M.H.)
| | - Cordelia Schuler
- Department of Gastroenterology and Hepatology, University Hospital Zurich, University of Zurich, 8091 Zurich, Switzerland; (C.d.V.); (J.C.-R.); (K.B.); (C.M.); (M.M.); (C.S.); (S.B.); (S.L.); (M.S.); (P.A.R.); (M.H.)
| | - Susan Bengs
- Department of Gastroenterology and Hepatology, University Hospital Zurich, University of Zurich, 8091 Zurich, Switzerland; (C.d.V.); (J.C.-R.); (K.B.); (C.M.); (M.M.); (C.S.); (S.B.); (S.L.); (M.S.); (P.A.R.); (M.H.)
| | - Silvia Lang
- Department of Gastroenterology and Hepatology, University Hospital Zurich, University of Zurich, 8091 Zurich, Switzerland; (C.d.V.); (J.C.-R.); (K.B.); (C.M.); (M.M.); (C.S.); (S.B.); (S.L.); (M.S.); (P.A.R.); (M.H.)
| | - Michael Scharl
- Department of Gastroenterology and Hepatology, University Hospital Zurich, University of Zurich, 8091 Zurich, Switzerland; (C.d.V.); (J.C.-R.); (K.B.); (C.M.); (M.M.); (C.S.); (S.B.); (S.L.); (M.S.); (P.A.R.); (M.H.)
- Zurich Center for Integrative Human Physiology, 8057 Zurich, Switzerland
| | - Klaus Seuwen
- Novartis Institutes for Biomedical Research, 4033 Basel, Switzerland;
| | - Pedro A. Ruiz
- Department of Gastroenterology and Hepatology, University Hospital Zurich, University of Zurich, 8091 Zurich, Switzerland; (C.d.V.); (J.C.-R.); (K.B.); (C.M.); (M.M.); (C.S.); (S.B.); (S.L.); (M.S.); (P.A.R.); (M.H.)
| | - Martin Hausmann
- Department of Gastroenterology and Hepatology, University Hospital Zurich, University of Zurich, 8091 Zurich, Switzerland; (C.d.V.); (J.C.-R.); (K.B.); (C.M.); (M.M.); (C.S.); (S.B.); (S.L.); (M.S.); (P.A.R.); (M.H.)
| | - Gerhard Rogler
- Department of Gastroenterology and Hepatology, University Hospital Zurich, University of Zurich, 8091 Zurich, Switzerland; (C.d.V.); (J.C.-R.); (K.B.); (C.M.); (M.M.); (C.S.); (S.B.); (S.L.); (M.S.); (P.A.R.); (M.H.)
- Zurich Center for Integrative Human Physiology, 8057 Zurich, Switzerland
- Correspondence: ; Tel.: +41-(0)44-255-2401
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13
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Weder B, Schefer F, van Haaften WT, Patsenker E, Stickel F, Mueller S, Hutter S, Schuler C, Baebler K, Wang Y, Mamie C, Dijkstra G, de Vallière C, Imenez Silva PH, Wagner CA, Frey-Wagner I, Ruiz PA, Seuwen K, Rogler G, Hausmann M. New Therapeutic Approach for Intestinal Fibrosis Through Inhibition of pH-Sensing Receptor GPR4. Inflamm Bowel Dis 2022; 28:109-125. [PMID: 34320209 DOI: 10.1093/ibd/izab140] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/11/2020] [Indexed: 02/06/2023]
Abstract
BACKGROUND Patients suffering from inflammatory bowel diseases (IBDs) express increased mucosal levels of pH-sensing receptors compared with non-IBD controls. Acidification leads to angiogenesis and extracellular matrix remodeling. We aimed to determine the expression of pH-sensing G protein-coupled receptor 4 (GPR4) in fibrotic lesions in Crohn's disease (CD) patients. We further evaluated the effect of deficiency in Gpr4 or its pharmacologic inhibition. METHODS Paired samples from fibrotic and nonfibrotic terminal ileum were obtained from CD patients undergoing ileocaecal resection. The effects of Gpr4 deficiency were assessed in the spontaneous Il-10-/- and the chronic dextran sodium sulfate (DSS) murine colitis model. The effects of Gpr4 deficiency and a GPR4 antagonist (39c) were assessed in the heterotopic intestinal transplantation model. RESULTS In human terminal ileum, increased expression of fibrosis markers was accompanied by an increase in GPR4 expression. A positive correlation between the expression of procollagens and GPR4 was observed. In murine disease models, Gpr4 deficiency was associated with a decrease in angiogenesis and fibrogenesis evidenced by decreased vessel length and expression of Edn, Vegfα, and procollagens. The heterotopic animal model for intestinal fibrosis, transplanted with terminal ileum from Gpr4-/- mice, revealed a decrease in mRNA expression of fibrosis markers and a decrease in collagen content and layer thickness compared with grafts from wild type mice. The GPR4 antagonist decreased collagen deposition. The GPR4 expression was also observed in human and murine intestinal fibroblasts. The GPR4 inhibition reduced markers of fibroblast activation stimulated by low pH, notably Acta2 and cTgf. CONCLUSIONS Expression of GPR4 positively correlates with the expression of profibrotic genes and collagen. Deficiency of Gpr4 is associated with a decrease in angiogenesis and fibrogenesis. The GPR4 antagonist decreases collagen deposition. Targeting GPR4 with specific inhibitors may constitute a new treatment option for IBD-associated fibrosis.
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Affiliation(s)
- Bruce Weder
- Department of Gastroenterology and Hepatology, University Hospital Zurich, Zurich, Switzerland
| | - Fabian Schefer
- Department of Gastroenterology and Hepatology, University Hospital Zurich, Zurich, Switzerland
| | - Wouter Tobias van Haaften
- Department of Gastroenterology and Hepatology, University Medical Center Groningen, University of Groningen, Groningen, the Netherlands.,Department of Pharmaceutical Technology and Biopharmacy, Groningen Research Institute of Pharmacy, University of Groningen, Groningen, the Netherlands
| | - Eleonora Patsenker
- Department of Gastroenterology and Hepatology, University Hospital Zurich, Zurich, Switzerland
| | - Felix Stickel
- Department of Gastroenterology and Hepatology, University Hospital Zurich, Zurich, Switzerland
| | - Sebastian Mueller
- Department of Internal Medicine and Center for Alcohol Research, Salem Medical Center University Hospital Heidelberg, Heidelberg, Germany
| | - Senta Hutter
- Department of Gastroenterology and Hepatology, University Hospital Zurich, Zurich, Switzerland
| | - Cordelia Schuler
- Department of Gastroenterology and Hepatology, University Hospital Zurich, Zurich, Switzerland
| | - Katharina Baebler
- Department of Gastroenterology and Hepatology, University Hospital Zurich, Zurich, Switzerland
| | - Yu Wang
- Department of Gastroenterology and Hepatology, University Hospital Zurich, Zurich, Switzerland
| | - Céline Mamie
- Department of Gastroenterology and Hepatology, University Hospital Zurich, Zurich, Switzerland
| | - Gerard Dijkstra
- Department of Gastroenterology and Hepatology, University Medical Center Groningen, University of Groningen, Groningen, the Netherlands
| | - Cheryl de Vallière
- Department of Gastroenterology and Hepatology, University Hospital Zurich, Zurich, Switzerland
| | - Pedro H Imenez Silva
- Institute of Physiology, University of Zurich, Zurich, Switzerland and National Center of Competence in Research Kidney Control of Homeostasis, Switzerland
| | - Carsten A Wagner
- Institute of Physiology, University of Zurich, Zurich, Switzerland and National Center of Competence in Research Kidney Control of Homeostasis, Switzerland
| | - Isabelle Frey-Wagner
- Department of Gastroenterology and Hepatology, University Hospital Zurich, Zurich, Switzerland
| | - Pedro A Ruiz
- Department of Gastroenterology and Hepatology, University Hospital Zurich, Zurich, Switzerland
| | - Klaus Seuwen
- Novartis Institutes for Biomedical Research, Forum1 Novartis Campus, Basel, Switzerland
| | - Gerhard Rogler
- Department of Gastroenterology and Hepatology, University Hospital Zurich, Zurich, Switzerland
| | - Martin Hausmann
- Department of Gastroenterology and Hepatology, University Hospital Zurich, Zurich, Switzerland
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14
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de Vallière C, Bäbler K, Busenhart P, Schwarzfischer M, Maeyashiki C, Schuler C, Atrott K, Lang S, Spalinger MR, Scharl M, Ruiz-Castro PA, Hausmann M, Rogler G. A Novel OGR1 (GPR68) Inhibitor Attenuates Inflammation in Murine Models of Colitis. Inflamm Intest Dis 2021; 6:140-153. [PMID: 34722644 DOI: 10.1159/000517474] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/25/2021] [Accepted: 05/13/2021] [Indexed: 01/17/2023] Open
Abstract
Background and Aims Local extracellular acidification is associated with several conditions, such as ischemia, cancer, metabolic disease, respiratory diseases, and inflammatory bowel disease (IBD). Several recent studies reported a link between IBD and a family of pH-sensing G protein-coupled receptors. Our previous studies point to an essential role for OGR1 (GPR68) in the modulation of intestinal inflammation and fibrosis. In the current study, we evaluated the effects of a novel OGR1 inhibitor in murine models of colitis. Methods The effects of a novel small-molecule OGR1 inhibitor were assessed in the acute and chronic dextran sulfate sodium (DSS) murine models of colitis. Macroscopic disease indicators of intestinal inflammation were evaluated, and epithelial damage and immune cell infiltration and proliferation were assessed by immunohistochemistry. Results The OGR1 inhibitor ameliorated clinical parameters in acute and chronic DSS-induced colitis. In mice treated with the OGR1 inhibitor, endoscopy showed no thickening and normal vascularity, while fibrin was not detected. Histopathological findings revealed a decrease in severity of colonic inflammation in the OGR1 inhibitor group when compared to vehicle-DSS controls. In OGR1 inhibitor-treated mice, staining for the macrophage marker F4/80 and cellular proliferation marker Ki-67 revealed a reduction of infiltrating macrophages and slightly enhanced cell proliferation, respectively. This was accompanied by a reduction in pro-inflammatory cytokines, TNF and IL-6, and the fibrosis marker TGF-β1. Conclusion This is the first report providing evidence that a pharmacological inhibition of OGR1 has a therapeutic effect in murine colitis models. Our data suggest that targeting proton-sensing OGR1 using specific small-molecule inhibitors may be a novel therapeutic approach for the treatment of IBD.
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Affiliation(s)
- Cheryl de Vallière
- Department of Gastroenterology and Hepatology, University Hospital Zurich, (USZ), University of Zurich, Zurich, Switzerland
| | - Katharina Bäbler
- Department of Gastroenterology and Hepatology, University Hospital Zurich, (USZ), University of Zurich, Zurich, Switzerland
| | - Philipp Busenhart
- Department of Gastroenterology and Hepatology, University Hospital Zurich, (USZ), University of Zurich, Zurich, Switzerland
| | - Marlene Schwarzfischer
- Department of Gastroenterology and Hepatology, University Hospital Zurich, (USZ), University of Zurich, Zurich, Switzerland
| | - Chiaki Maeyashiki
- Department of Gastroenterology and Hepatology, University Hospital Zurich, (USZ), University of Zurich, Zurich, Switzerland
| | - Cordelia Schuler
- Department of Gastroenterology and Hepatology, University Hospital Zurich, (USZ), University of Zurich, Zurich, Switzerland
| | - Kirstin Atrott
- Department of Gastroenterology and Hepatology, University Hospital Zurich, (USZ), University of Zurich, Zurich, Switzerland
| | - Silvia Lang
- Department of Gastroenterology and Hepatology, University Hospital Zurich, (USZ), University of Zurich, Zurich, Switzerland
| | - Marianne R Spalinger
- Department of Gastroenterology and Hepatology, University Hospital Zurich, (USZ), University of Zurich, Zurich, Switzerland
| | - Michael Scharl
- Department of Gastroenterology and Hepatology, University Hospital Zurich, (USZ), University of Zurich, Zurich, Switzerland.,Zurich Center for Integrative Human Physiology, Zurich, Switzerland
| | - Pedro A Ruiz-Castro
- Department of Gastroenterology and Hepatology, University Hospital Zurich, (USZ), University of Zurich, Zurich, Switzerland
| | - Martin Hausmann
- Department of Gastroenterology and Hepatology, University Hospital Zurich, (USZ), University of Zurich, Zurich, Switzerland
| | - Gerhard Rogler
- Department of Gastroenterology and Hepatology, University Hospital Zurich, (USZ), University of Zurich, Zurich, Switzerland.,Zurich Center for Integrative Human Physiology, Zurich, Switzerland
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15
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Park I, Phan TM, Fang J. Novel Molecular Mechanism of Lenalidomide in Myeloid Malignancies Independent of Deletion of Chromosome 5q. Cancers (Basel) 2021; 13:5084. [PMID: 34680233 PMCID: PMC8534127 DOI: 10.3390/cancers13205084] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2021] [Revised: 09/30/2021] [Accepted: 10/08/2021] [Indexed: 12/26/2022] Open
Abstract
Lenalidomide as well as other immunomodulatory drugs (IMiDs) have achieved clinical efficacies in certain sub-types of hematologic malignancies, such as multiple myeloma, lower-risk myelodysplastic syndromes (MDS) with a single deletion of chromosome 5q (del(5q)) and others. Despite superior clinical response to lenalidomide in hematologic malignancies, relapse and resistance remains a problem in IMiD-based therapy. The last ten years have witnessed the discovery of novel molecular mechanism of IMiD-based anti-tumor therapy. IMiDs bind human cereblon (CRBN), the substrate receptor of the CRL4 E3 ubiquitin ligase complex. Binding of CRBN with IMiDs leads to degradation of the Ikaros family zinc finger proteins 1 and 3 (IKZF1 and IKZF3) and casein kinase 1 alpha. We have found that lenalidomide-mediated degradation of IKZF1 leads to activation of the G protein-coupled receptor 68 (GPR68)/calcium/calpain pro-apoptotic pathway and inhibition of the regulator of calcineurin 1 (RCAN1)/calcineurin pro-survival pathway in MDS and acute myeloid leukemia (AML). Calcineurin inhibitor Cyclosporin-A potentiates the anti-leukemia activity of lenalidomide in MDS/AML with or without del(5q). These findings broaden the therapeutic potential of IMiDs. This review summarizes novel molecular mechanism of lenalidomide in myeloid malignancies, especially without del(5q), in the hope to highlight novel therapeutic targets.
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Affiliation(s)
| | | | - Jing Fang
- Department of Drug Discovery and Biomedical Sciences, University of South Carolina College of Pharmacy, Columbia, SC 29208, USA; (I.P.); (T.M.P.)
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Krieger NS, Bushinsky DA. Metabolic Acidosis Regulates RGS16 and G-protein Signaling in Osteoblasts. Am J Physiol Renal Physiol 2021; 321:F424-F430. [PMID: 34396788 DOI: 10.1152/ajprenal.00166.2021] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Chronic metabolic acidosis stimulates cell-mediated net calcium efflux from bone mediated by increased osteoblastic cyclooxygenase 2 (COX2), leading to prostaglandin E2-induced stimulation of RANKL-induced osteoclastic bone resorption. The osteoblastic H+-sensing G-protein coupled receptor (GPCR), OGR1, is activated by acidosis and leads to increased bne resorption. As regulators of G protein signaling (RGS) proteins limit GPCR signaling, we tested whether RGS proteins themselves are regulated by metabolic acidosis. Primary osteoblasts were isolated from neonatal mouse calvariae and incubated in physiological neutral (NTL) or acidic (MET) medium. Cells were collected and RNA extracted for real time PCR analysis with mRNA levels normalized to RPL13a. RGS1, RGS2, RGS3, RGS4, RGS10, RGS11 or RGS18mRNA did not differ between MET and NTL; however by 30' MET decreased RGS16 which persisted for 60' and 3h. Incubation of osteoblasts with the OGR1 inhibitor CuCl2 inhibited the MET induced increase in RGS16 mRNA. Gallein, a specific inhibitor of Gβγ signaling, was used to determine if downstream signaling by the βγ subunit was critical for the response to acidosis. Gallein decreased net Ca efflux from calvariae and COX2 and RANKL gene expression from isolated osteoblasts. These results indicate that regulation of RGS16 plays an important role in modulating the response of the osteoblastic GPCR, OGR1, to metabolic acidosis and subsequent stimulation of osteoclastic bone resorption.
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Affiliation(s)
- Nancy S Krieger
- Division of Nephrology, Department of Medicine, University of Rochester Medical Center, Rochester, NY, United States
| | - David A Bushinsky
- Division of Nephrology, Department of Medicine, University of Rochester Medical Center, Rochester, NY, United States
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17
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Ion Channels, Transporters, and Sensors Interact with the Acidic Tumor Microenvironment to Modify Cancer Progression. Rev Physiol Biochem Pharmacol 2021; 182:39-84. [PMID: 34291319 DOI: 10.1007/112_2021_63] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Abstract
Solid tumors, including breast carcinomas, are heterogeneous but typically characterized by elevated cellular turnover and metabolism, diffusion limitations based on the complex tumor architecture, and abnormal intra- and extracellular ion compositions particularly as regards acid-base equivalents. Carcinogenesis-related alterations in expression and function of ion channels and transporters, cellular energy levels, and organellar H+ sequestration further modify the acid-base composition within tumors and influence cancer cell functions, including cell proliferation, migration, and survival. Cancer cells defend their cytosolic pH and HCO3- concentrations better than normal cells when challenged with the marked deviations in extracellular H+, HCO3-, and lactate concentrations typical of the tumor microenvironment. Ionic gradients determine the driving forces for ion transporters and channels and influence the membrane potential. Cancer and stromal cells also sense abnormal ion concentrations via intra- and extracellular receptors that modify cancer progression and prognosis. With emphasis on breast cancer, the current review first addresses the altered ion composition and the changes in expression and functional activity of ion channels and transporters in solid cancer tissue. It then discusses how ion channels, transporters, and cellular sensors under influence of the acidic tumor microenvironment shape cancer development and progression and affect the potential of cancer therapies.
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18
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Ritter M, Bresgen N, Kerschbaum HH. From Pinocytosis to Methuosis-Fluid Consumption as a Risk Factor for Cell Death. Front Cell Dev Biol 2021; 9:651982. [PMID: 34249909 PMCID: PMC8261248 DOI: 10.3389/fcell.2021.651982] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2021] [Accepted: 04/29/2021] [Indexed: 12/11/2022] Open
Abstract
The volumes of a cell [cell volume (CV)] and its organelles are adjusted by osmoregulatory processes. During pinocytosis, extracellular fluid volume equivalent to its CV is incorporated within an hour and membrane area equivalent to the cell's surface within 30 min. Since neither fluid uptake nor membrane consumption leads to swelling or shrinkage, cells must be equipped with potent volume regulatory mechanisms. Normally, cells respond to outwardly or inwardly directed osmotic gradients by a volume decrease and increase, respectively, i.e., they shrink or swell but then try to recover their CV. However, when a cell death (CD) pathway is triggered, CV persistently decreases in isotonic conditions in apoptosis and it increases in necrosis. One type of CD associated with cell swelling is due to a dysfunctional pinocytosis. Methuosis, a non-apoptotic CD phenotype, occurs when cells accumulate too much fluid by macropinocytosis. In contrast to functional pinocytosis, in methuosis, macropinosomes neither recycle nor fuse with lysosomes but with each other to form giant vacuoles, which finally cause rupture of the plasma membrane (PM). Understanding methuosis longs for the understanding of the ionic mechanisms of cell volume regulation (CVR) and vesicular volume regulation (VVR). In nascent macropinosomes, ion channels and transporters are derived from the PM. Along trafficking from the PM to the perinuclear area, the equipment of channels and transporters of the vesicle membrane changes by retrieval, addition, and recycling from and back to the PM, causing profound changes in vesicular ion concentrations, acidification, and-most importantly-shrinkage of the macropinosome, which is indispensable for its proper targeting and cargo processing. In this review, we discuss ion and water transport mechanisms with respect to CVR and VVR and with special emphasis on pinocytosis and methuosis. We describe various aspects of the complex mutual interplay between extracellular and intracellular ions and ion gradients, the PM and vesicular membrane, phosphoinositides, monomeric G proteins and their targets, as well as the submembranous cytoskeleton. Our aim is to highlight important cellular mechanisms, components, and processes that may lead to methuotic CD upon their derangement.
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Affiliation(s)
- Markus Ritter
- Center for Physiology, Pathophysiology and Biophysics, Institute for Physiology and Pathophysiology, Paracelsus Medical University, Salzburg, Austria
- Institute for Physiology and Pathophysiology, Paracelsus Medical University, Nuremberg, Germany
- Gastein Research Institute, Paracelsus Medical University, Salzburg, Austria
- Ludwig Boltzmann Institute for Arthritis und Rehabilitation, Salzburg, Austria
- Kathmandu University School of Medical Sciences, Dhulikhel, Nepal
| | - Nikolaus Bresgen
- Department of Biosciences, University of Salzburg, Salzburg, Austria
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19
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Alhouayek M, Ameraoui H, Muccioli GG. Bioactive lipids in inflammatory bowel diseases - From pathophysiological alterations to therapeutic opportunities. Biochim Biophys Acta Mol Cell Biol Lipids 2020; 1866:158854. [PMID: 33157277 DOI: 10.1016/j.bbalip.2020.158854] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2020] [Revised: 10/16/2020] [Accepted: 10/27/2020] [Indexed: 12/12/2022]
Abstract
Inflammatory bowel diseases (IBDs), such as Crohn's disease and ulcerative colitis, are lifelong diseases that remain challenging to treat. IBDs are characterized by alterations in intestinal barrier function and dysregulation of the innate and adaptive immunity. An increasing number of lipids are found to be important regulators of inflammation and immunity as well as gut physiology. Therefore, the study of lipid mediators in IBDs is expected to improve our understanding of disease pathogenesis and lead to novel therapeutic opportunities. Here, through selected examples - such as fatty acids, specialized proresolving mediators, lysophospholipids, endocannabinoids, and oxysterols - we discuss how lipid signaling is involved in IBD physiopathology and how modulating lipid signaling pathways could affect IBDs.
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Affiliation(s)
- Mireille Alhouayek
- Bioanalysis and Pharmacology of Bioactive Lipids Research Group, Louvain Drug Research Institute, Université catholique de Louvain, 1200 Bruxelles, Belgium.
| | - Hafsa Ameraoui
- Bioanalysis and Pharmacology of Bioactive Lipids Research Group, Louvain Drug Research Institute, Université catholique de Louvain, 1200 Bruxelles, Belgium
| | - Giulio G Muccioli
- Bioanalysis and Pharmacology of Bioactive Lipids Research Group, Louvain Drug Research Institute, Université catholique de Louvain, 1200 Bruxelles, Belgium.
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20
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Foata F, Sprenger N, Rochat F, Damak S. Activation of the G-protein coupled receptor GPR35 by human milk oligosaccharides through different pathways. Sci Rep 2020; 10:16117. [PMID: 32999316 PMCID: PMC7528069 DOI: 10.1038/s41598-020-73008-0] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2020] [Accepted: 09/10/2020] [Indexed: 12/19/2022] Open
Abstract
Numerous benefits of breastfeeding over infant formula are fully established. The superiority of human milk over bovine milk-based formula is partly due to human milk oligosaccharides (HMOs), a family of over 100 molecules present specifically and substantially in human milk that resemble mucosal glycans. To uncover novel physiological functions and pathways of HMOs, we screened a panel of 165 G-protein coupled receptors (GPCRs) using a blend of 6 HMOs (3'-O-sialyllactose (3'SL), 6'-O-sialyllactose (6'SL), lacto-N-tetraose (LNT), lacto-N-neo-tetraose (LNnT), 2-O-fucosyllactose (2'FL), and difucosyllactose (diFL)), and followed up positive hits with standard receptor assays. The HMO blend specifically activated GPR35. LNT and 6'SL individually activated GPR35, and they showed synergy when used together. In addition, in vitro fermentation of infant stool samples showed that 2'FL upregulates the production of the GPR35 agonist kynurenic acid (KYNA) by the microbiota. LNT + 6'SL and KYNA showed additive activation of GPR35. Activation by 6'SL and LNT of GPR35, a receptor mediating attenuation of pain and colitis, is to our knowledge the first demonstration of GPCR activation by any HMO. In addition, we demonstrated a remarkable cooperation between nutrition and microbiota towards activation of a host receptor highlighting the close interplay between environment and host-microbe interactions.
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Affiliation(s)
- Francis Foata
- Société des Produits Nestlé S.A., Nestlé Research, Route du Jorat, Vers-chez-les-Blanc, 1000, Lausanne 26, Switzerland
| | - Norbert Sprenger
- Société des Produits Nestlé S.A., Nestlé Research, Route du Jorat, Vers-chez-les-Blanc, 1000, Lausanne 26, Switzerland
| | - Florence Rochat
- Société des Produits Nestlé S.A., Nestlé Research, Route du Jorat, Vers-chez-les-Blanc, 1000, Lausanne 26, Switzerland
| | - Sami Damak
- Société des Produits Nestlé S.A., Nestlé Research, Route du Jorat, Vers-chez-les-Blanc, 1000, Lausanne 26, Switzerland.
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21
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Huang XP, Kenakin TP, Gu S, Shoichet BK, Roth BL. Differential Roles of Extracellular Histidine Residues of GPR68 for Proton-Sensing and Allosteric Modulation by Divalent Metal Ions. Biochemistry 2020; 59:3594-3614. [PMID: 32865988 DOI: 10.1021/acs.biochem.0c00576] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
GPR68, an orphan G-protein coupled receptor, senses protons, couples to multiple G-proteins, and is also activated or inhibited by divalent metal ions. It has seven extracellular histidine residues, although it is not clear how these histidine residues play a role in both proton-sensing and metal ion modulation. Here we demonstrate that divalent metal ions are allosteric modulators that can activate or inhibit proton activity in a concentration- and pH-dependent manner. We then show that single histidine mutants have differential and varying degrees of effects on proton-sensing and metal ion modulation. Some histidine residues play dual roles in proton-sensing and metal ion modulation, while others are important in one or the other but not both. Two extracellular disulfide bonds are predicted to constrain histidine residues to be spatially close to each other. Combining histidine mutations leads to reduced proton activity and resistance to metal ion modulation, while breaking the less conserved disulfide bond results in a more severe reduction in proton-sensing over metal modulation. The small-molecule positive allosteric modulators (PAMs) ogerin and lorazepam are not affected by these mutations and remain active at mutants with severely reduced proton activity or are resistant to metal ion modulation. These results suggest GPR68 possesses two independent allosteric modulation systems, one through interaction with divalent metal ions at the extracellular surface and another through small-molecule PAMs in the transmembrane domains. A new GPR68 model is developed to accommodate the findings which could serve as a template for further studies and ligand discovery by virtual ligand docking.
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Affiliation(s)
| | | | - Shuo Gu
- Department of Pharmaceutical Science, University of California, San Francisco, California 94158, United States
| | - Brian K Shoichet
- Department of Pharmaceutical Science, University of California, San Francisco, California 94158, United States
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Serova OV, Gantsova EA, Deyev IE, Petrenko AG. The Value of pH Sensors in Maintaining Homeostasis of the Nervous System. RUSSIAN JOURNAL OF BIOORGANIC CHEMISTRY 2020. [DOI: 10.1134/s1068162020040196] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
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23
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McDonough W, Aragon IV, Rich J, Murphy JM, Abou Saleh L, Boyd A, Koloteva A, Richter W. PAN-selective inhibition of cAMP-phosphodiesterase 4 (PDE4) induces gastroparesis in mice. FASEB J 2020; 34:12533-12548. [PMID: 32738081 DOI: 10.1096/fj.202001016rr] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2020] [Revised: 07/06/2020] [Accepted: 07/07/2020] [Indexed: 12/12/2022]
Abstract
Inhibitors of cAMP-phosphodiesterase 4 (PDE4) exert a number of promising therapeutic benefits, but adverse effects, in particular emesis and nausea, have curbed their clinical utility. Here, we show that PAN-selective inhibition of PDE4, but not inhibition of PDE3, causes a time- and dose-dependent accumulation of chow in the stomachs of mice fed ad libitum without changing the animals' food intake or the weight of their intestines, suggesting that PDE4 inhibition impairs gastric emptying. Indeed, PDE4 inhibition induced gastric retention in an acute model of gastric motility that traces the passage of a food bolus through the stomach over a 30 minutes time period. In humans, abnormal gastric retention of food is known as gastroparesis, a syndrome predominated by nausea (>90% of cases) and vomiting (>80% of cases). We thus explored the abnormal gastric retention induced by PDE4 inhibition in mice under the premise that it may represent a useful correlate of emesis and nausea. Delayed gastric emptying was produced by structurally distinct PAN-PDE4 inhibitors including Rolipram, Piclamilast, Roflumilast, and RS25344, suggesting that it is a class effect. PDE4 inhibitors induced gastric retention at similar or below doses commonly used to induce therapeutic benefits (e.g., 0.04 mg/kg Rolipram), thus mirroring the narrow therapeutic window of PDE4 inhibitors in humans. YM976, a PAN-PDE4 inhibitor that does not efficiently cross the blood-brain barrier, induced gastroparesis only at significantly higher doses (≥1 mg/kg). This suggests that PDE4 inhibition may act in part through effects on the autonomic nervous system regulation of gastric emptying and that PDE4 inhibitors that are not brain-penetrant may have an improved safety profile. The PDE4 family comprises four subtypes, PDE4A, B, C, and D. Selective ablation of any of these subtypes in mice did not induce gastroparesis per se, nor did it protect from PAN-PDE4 inhibitor-induced gastroparesis, indicating that gastric retention may result from the concurrent inhibition of multiple PDE4s. Thus, potentially, any of the four PDE4 subtypes may be targeted individually for therapeutic benefits without inducing nausea or emesis. Acute gastric retention induced by PDE4 inhibition is alleviated by treatment with the widely used prokinetic Metoclopramide, suggesting a potential of this drug to alleviate the side effects of PDE4 inhibitors. Finally, given that the cause of gastroparesis remains largely idiopathic, our findings open the possibility that a physiologic or pathophysiologic downregulation of PDE4 activity/expression may be causative in a subset of patients.
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Affiliation(s)
- Will McDonough
- Department of Biochemistry & Molecular Biology, Center for Lung Biology, University of South Alabama College of Medicine, Mobile, AL, USA
| | - Ileana V Aragon
- Department of Biochemistry & Molecular Biology, Center for Lung Biology, University of South Alabama College of Medicine, Mobile, AL, USA
| | - Justin Rich
- Department of Biochemistry & Molecular Biology, Center for Lung Biology, University of South Alabama College of Medicine, Mobile, AL, USA
| | - James M Murphy
- Department of Biochemistry & Molecular Biology, Center for Lung Biology, University of South Alabama College of Medicine, Mobile, AL, USA
| | - Lina Abou Saleh
- Department of Biochemistry & Molecular Biology, Center for Lung Biology, University of South Alabama College of Medicine, Mobile, AL, USA
| | - Abigail Boyd
- Department of Biochemistry & Molecular Biology, Center for Lung Biology, University of South Alabama College of Medicine, Mobile, AL, USA
| | - Anna Koloteva
- Department of Biochemistry & Molecular Biology, Center for Lung Biology, University of South Alabama College of Medicine, Mobile, AL, USA
| | - Wito Richter
- Department of Biochemistry & Molecular Biology, Center for Lung Biology, University of South Alabama College of Medicine, Mobile, AL, USA
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24
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He X, Hawkins C, Lawley L, Freeman K, Phan TM, Zhang J, Xu Y, Fang J. Whole body deletion of Gpr68 does not change hematopoietic stem cell function. Stem Cell Res 2020; 47:101869. [PMID: 32592951 PMCID: PMC7749853 DOI: 10.1016/j.scr.2020.101869] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/05/2020] [Revised: 05/21/2020] [Accepted: 05/29/2020] [Indexed: 11/17/2022] Open
Abstract
G protein-coupled receptor 68 (GPR68) responds to extracellular protons, thus called the proton-sensing G protein-coupled receptor (GPCR), leading to activation of the phospholipase C-β (PLCβ)/calcium (Ca2+) pathway or the adenylyl cyclase (AC)/cyclic AMP (cAMP) pathway. We recently found that whole body deletion of Gpr68 (Gpr68-/- mice) reduced the number of B lymphocytes with age and during hematopoietic regeneration, such as in response to fluorouracil (5-FU) administration. This prompted us to characterize the hematopoietic stem cell (HSC) phenotype in Gpr68-/- mice. Despite high level of Gpr68 protein expression on HSC in bone marrow (BM), the pool size of HSC was unaltered in Gpr68-/- mice either under steady state or upon stress, including aging and 5-FU treatment. HSC from Gpr68-/- mice exhibited comparable cellular features, such as cell cycle quiescence and cell survival. HSC from Gpr68-/- mice also exhibited comparable competitiveness after serial transplantation. Surprisingly, cytosolic Ca2+ accumulation was increased in HSC from Gpr68-/- mice. In contrast, cAMP levels were reduced in hematopoietic stem and progenitor cells (HSPC) from Gpr68-/- mice. Intriguingly, we found high level of Gpr68 protein expression on non-hematopoietic cells in BM, especially endothelial cells that function as HSC niche. In addition, expression of other proton-sensing GPCR was upregulated in HSPC from Gpr68-/- mice. Our studies suggest that Gpr68-/- mice display insignificant phenotype on HSC biology, possibly due to the function of Gpr68 in non-hematopoietic cells and/or the compensatory effects from other proton-sensing GPCR.
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Affiliation(s)
- Xiaofei He
- Department of Drug Discovery and Biomedical Sciences, University of South Carolina College of Pharmacy, Columbia, SC, USA
| | - Caleb Hawkins
- Department of Drug Discovery and Biomedical Sciences, University of South Carolina College of Pharmacy, Columbia, SC, USA
| | - Lauren Lawley
- Department of Drug Discovery and Biomedical Sciences, University of South Carolina College of Pharmacy, Columbia, SC, USA
| | - Kennedy Freeman
- Department of Drug Discovery and Biomedical Sciences, University of South Carolina College of Pharmacy, Columbia, SC, USA
| | - Tra Mi Phan
- Department of Drug Discovery and Biomedical Sciences, University of South Carolina College of Pharmacy, Columbia, SC, USA
| | - Jiajia Zhang
- Department of Epidemiology and Biostatistics, University of South Carolina Arnold School of Public Health, Columbia, SC, USA
| | - Yan Xu
- Department of Obstetrics and Gynecology, Indiana University School of Medicine, Indianapolis, IN, USA
| | - Jing Fang
- Department of Drug Discovery and Biomedical Sciences, University of South Carolina College of Pharmacy, Columbia, SC, USA.
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25
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Nayak AP, Penn RB. The proton-sensing receptor ovarian cancer G-protein coupled receptor 1 (OGR1) in airway physiology and disease. Curr Opin Pharmacol 2020; 51:1-10. [PMID: 32361614 DOI: 10.1016/j.coph.2020.03.004] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2020] [Revised: 03/22/2020] [Accepted: 03/26/2020] [Indexed: 12/28/2022]
Abstract
Numerous G protein-coupled receptors (GPCRs) regulate multiple airway functions and play fundamental roles in normal and aberrant airway and lung physiology. Thus, GPCRs are prime candidates of targeting by disease therapeutics. The intriguing proton-sensing GPCR Ovarian cancer G-protein coupled receptor 1 (OGR1; aka GPR68) has recently been shown capable of regulating airway smooth muscle (ASM) contraction and proliferation. Although the study of OGR1 has been confounded by the fact that the proton is the presumed cognate ligand of OGR1, recent studies have begun to identify novel ligands and modulators capable of regulating the diverse signaling, and functional role of OGR1. Such studies offer hope for OGR1-targeting drugs as therapeutics for obstructive lung diseases such as asthma. Herein, we review the literature to date detailing the receptor biology and pharmacology of OGR1, receptor function in the airway, and describe the potential clinical utility of OGR1-modulating drugs.
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Affiliation(s)
- Ajay P Nayak
- Department of Medicine, Division of Pulmonary and Critical Care Medicine, Center for Translational Medicine, Jane and Leonard Korman Lung Institute, Thomas Jefferson University, 1020 Locust St., Suite 543G JAH, Philadelphia, PA, 19107, United States.
| | - Raymond B Penn
- Department of Medicine, Division of Pulmonary and Critical Care Medicine, Center for Translational Medicine, Jane and Leonard Korman Lung Institute, Thomas Jefferson University, 1020 Locust St., Suite 543G JAH, Philadelphia, PA, 19107, United States.
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26
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Engevik AC, Kaji I, Goldenring JR. The Physiology of the Gastric Parietal Cell. Physiol Rev 2020; 100:573-602. [PMID: 31670611 PMCID: PMC7327232 DOI: 10.1152/physrev.00016.2019] [Citation(s) in RCA: 101] [Impact Index Per Article: 25.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2019] [Revised: 10/10/2019] [Accepted: 10/13/2019] [Indexed: 12/11/2022] Open
Abstract
Parietal cells are responsible for gastric acid secretion, which aids in the digestion of food, absorption of minerals, and control of harmful bacteria. However, a fine balance of activators and inhibitors of parietal cell-mediated acid secretion is required to ensure proper digestion of food, while preventing damage to the gastric and duodenal mucosa. As a result, parietal cell secretion is highly regulated through numerous mechanisms including the vagus nerve, gastrin, histamine, ghrelin, somatostatin, glucagon-like peptide 1, and other agonists and antagonists. The tight regulation of parietal cells ensures the proper secretion of HCl. The H+-K+-ATPase enzyme expressed in parietal cells regulates the exchange of cytoplasmic H+ for extracellular K+. The H+ secreted into the gastric lumen by the H+-K+-ATPase combines with luminal Cl- to form gastric acid, HCl. Inhibition of the H+-K+-ATPase is the most efficacious method of preventing harmful gastric acid secretion. Proton pump inhibitors and potassium competitive acid blockers are widely used therapeutically to inhibit acid secretion. Stimulated delivery of the H+-K+-ATPase to the parietal cell apical surface requires the fusion of intracellular tubulovesicles with the overlying secretory canaliculus, a process that represents the most prominent example of apical membrane recycling. In addition to their unique ability to secrete gastric acid, parietal cells also play an important role in gastric mucosal homeostasis through the secretion of multiple growth factor molecules. The gastric parietal cell therefore plays multiple roles in gastric secretion and protection as well as coordination of physiological repair.
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Affiliation(s)
- Amy C Engevik
- Departments of Surgery and of Cell and Developmental Biology and the Epithelial Biology Center, Vanderbilt University School of Medicine, Vanderbilt University Medical Center and the Nashville VA Medical Center, Nashville, Tennessee
| | - Izumi Kaji
- Departments of Surgery and of Cell and Developmental Biology and the Epithelial Biology Center, Vanderbilt University School of Medicine, Vanderbilt University Medical Center and the Nashville VA Medical Center, Nashville, Tennessee
| | - James R Goldenring
- Departments of Surgery and of Cell and Developmental Biology and the Epithelial Biology Center, Vanderbilt University School of Medicine, Vanderbilt University Medical Center and the Nashville VA Medical Center, Nashville, Tennessee
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27
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Parks SK, Mueller-Klieser W, Pouysségur J. Lactate and Acidity in the Cancer Microenvironment. ANNUAL REVIEW OF CANCER BIOLOGY-SERIES 2020. [DOI: 10.1146/annurev-cancerbio-030419-033556] [Citation(s) in RCA: 35] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Fermentative glycolysis, an ancient evolved metabolic pathway, is exploited by rapidly growing tissues and tumors but also occurs in response to the nutritional and energetic demands of differentiated tissues. The lactic acid it produces is transported across cell membranes through reversible H+/lactate−symporters (MCT1 and MCT4) and is recycled in organs as a major metabolic precursor of gluconeogenesis and an energy source. Concentrations of lactate in the tumor environment, investigated utilizing an induced metabolic bioluminescence imaging (imBI) technique, appear to be dominant biomarkers of tumor response to irradiation and resistance to treatment. Suppression of lactic acid formation by genetic disruption of lactate dehydrogenases A and B in aggressive tumors reactivated OXPHOS (oxidative phosphorylation) to maintain xenograft tumor growth at a halved rate. In contrast, disruption of the lactic acid transporters MCT1/4 suppressed glycolysis, mTORC1, and tumor growth as a result of intracellular acidosis. Furthermore, the global reduction of tumor acidity contributes to activation of the antitumor immune responses, offering hope for future clinical applications.
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Affiliation(s)
- Scott K. Parks
- Department of Medical Biology, Centre Scientifique de Monaco (CSM), 98000 Monaco
| | - Wolfgang Mueller-Klieser
- Institute of Pathophysiology, University Medical Center, Johannes Gutenberg University Mainz, 55128 Mainz, Germany
| | - Jacques Pouysségur
- Department of Medical Biology, Centre Scientifique de Monaco (CSM), 98000 Monaco
- Institute for Research on Cancer and Aging, Nice (IRCAN), CNRS UMR 7284, INSERM U1081, Centre A. Lacassagne, University Côte d'Azur, 06189 Nice, France
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28
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Abstract
The microenvironment of solid tumors is often acidic due to poor vascular perfusion, regional hypoxia, and increased glycolytic activity of tumor cells. Although acidosis is harmful to most types of cells, tumor cells seem well adapted to such harsh conditions. Moreover, overwhelming evidence indicates that tumor cells are more invasive and more aggressive in acidic conditions by a cascade of cell signaling and upregulation of oncogenic gene expression. Therefore, how extracellular acidic signals are transduced to the cytoplasm and then into the nucleus is an interesting topic to many cancer researchers. In this review, we update on the recent advances in acidosis-induced tumorigenesis through the acid-sensing ion channels (ASICs) and activation of cell signaling.
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Affiliation(s)
- Liu Yang
- Key Laboratory of Tumor Molecular Diagnosis and Individualized Medicine of Zhejiang Province, Zhejiang Provincial People's Hospital, People's Hospital of Hangzhou Medical College, Hangzhou, 310014, Zhejiang, P.R. China
| | - Xiaoge Hu
- Key Laboratory of Tumor Molecular Diagnosis and Individualized Medicine of Zhejiang Province, Zhejiang Provincial People's Hospital, People's Hospital of Hangzhou Medical College, Hangzhou, 310014, Zhejiang, P.R. China.,Cancer Institute and Department of Pharmacology/Toxicology, University of Mississippi Medical Center, Jackson, MS, USA
| | - Yin-Yuan Mo
- Cancer Institute and Department of Pharmacology/Toxicology, University of Mississippi Medical Center, Jackson, MS, USA.
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29
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Maeyashiki C, Melhem H, Hering L, Baebler K, Cosin-Roger J, Schefer F, Weder B, Hausmann M, Scharl M, Rogler G, de Vallière C, Ruiz PA. Activation of pH-Sensing Receptor OGR1 (GPR68) Induces ER Stress Via the IRE1α/JNK Pathway in an Intestinal Epithelial Cell Model. Sci Rep 2020; 10:1438. [PMID: 31996710 PMCID: PMC6989664 DOI: 10.1038/s41598-020-57657-9] [Citation(s) in RCA: 36] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2019] [Accepted: 12/31/2019] [Indexed: 12/15/2022] Open
Abstract
Proton-sensing ovarian cancer G-protein coupled receptor (OGR1) plays an important role in pH homeostasis. Acidosis occurs at sites of intestinal inflammation and can induce endoplasmic reticulum (ER) stress and the unfolded protein response (UPR), an evolutionary mechanism that enables cells to cope with stressful conditions. ER stress activates autophagy, and both play important roles in gut homeostasis and contribute to the pathogenesis of inflammatory bowel disease (IBD). Using a human intestinal epithelial cell model, we investigated whether our previously observed protective effects of OGR1 deficiency in experimental colitis are associated with a differential regulation of ER stress, the UPR and autophagy. Caco-2 cells stably overexpressing OGR1 were subjected to an acidic pH shift. pH-dependent OGR1-mediated signalling led to a significant upregulation in the ER stress markers, binding immunoglobulin protein (BiP) and phospho-inositol required 1α (IRE1α), which was reversed by a novel OGR1 inhibitor and a c-Jun N-terminal kinase (JNK) inhibitor. Proton-activated OGR1-mediated signalling failed to induce apoptosis, but triggered accumulation of total microtubule-associated protein 1 A/1B-light chain 3, suggesting blockage of late stage autophagy. Our results show novel functions for OGR1 in the regulation of ER stress through the IRE1α-JNK signalling pathway, as well as blockage of autophagosomal degradation. OGR1 inhibition might represent a novel therapeutic approach in IBD.
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Affiliation(s)
- Chiaki Maeyashiki
- Department of Gastroenterology and Hepatology, University Hospital Zurich, Zurich, Switzerland
| | - Hassan Melhem
- Department of Gastroenterology and Hepatology, University Hospital Zurich, Zurich, Switzerland
| | - Larissa Hering
- Department of Gastroenterology and Hepatology, University Hospital Zurich, Zurich, Switzerland
| | - Katharina Baebler
- Department of Gastroenterology and Hepatology, University Hospital Zurich, Zurich, Switzerland
| | - Jesus Cosin-Roger
- Department of Gastroenterology and Hepatology, University Hospital Zurich, Zurich, Switzerland
| | - Fabian Schefer
- Department of Gastroenterology and Hepatology, University Hospital Zurich, Zurich, Switzerland
| | - Bruce Weder
- Department of Gastroenterology and Hepatology, University Hospital Zurich, Zurich, Switzerland
| | - Martin Hausmann
- Department of Gastroenterology and Hepatology, University Hospital Zurich, Zurich, Switzerland
| | - Michael Scharl
- Department of Gastroenterology and Hepatology, University Hospital Zurich, Zurich, Switzerland.,Zurich Center for Integrative Human Physiology, Zurich, Switzerland
| | - Gerhard Rogler
- Department of Gastroenterology and Hepatology, University Hospital Zurich, Zurich, Switzerland.,Zurich Center for Integrative Human Physiology, Zurich, Switzerland
| | - Cheryl de Vallière
- Department of Gastroenterology and Hepatology, University Hospital Zurich, Zurich, Switzerland.
| | - Pedro A Ruiz
- Department of Gastroenterology and Hepatology, University Hospital Zurich, Zurich, Switzerland.
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30
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Tian C, Huang R, Tang F, Lin Z, Cheng N, Han X, Li S, Zhou P, Deng S, Huang H, Zhao H, Xu J, Li Z. Transient Receptor Potential Ankyrin 1 Contributes to Lysophosphatidylcholine-Induced Intracellular Calcium Regulation and THP-1-Derived Macrophage Activation. J Membr Biol 2019; 253:43-55. [PMID: 31820013 DOI: 10.1007/s00232-019-00104-2] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2019] [Accepted: 11/26/2019] [Indexed: 12/21/2022]
Abstract
Lysophosphatidylcholine (LPC) is a major atherogenic lipid that stimulates an increase in mitochondrial reactive oxygen species (mtROS) and the release of cytokines under inflammasome activation. However, the potential receptors of LPC in macrophages are poorly understood. Members of the transient receptor potential (TRP) channel superfamily, which is crucially involved in transducing environmental irritant stimuli into nociceptor activity, are potential receptors of LPC. In this study, we investigated whether LPC can induce the activation of transient receptor potential ankyrin 1 (TRPA1), a member of the TRP superfamily. The functional expression of TRPA1 was first detected by quantitative real-time polymerase chain reaction (qRT-PCR), western blotting and calcium imaging in human acute monocytic leukemia cell line (THP-1)-derived macrophages. The mechanism by which LPC induces the activation of macrophages through TRPA1 was verified by cytoplasmic and mitochondrial calcium imaging, mtROS detection, a JC-1 assay, enzyme-linked immunosorbent assay, the CCK-8 assay and the lactate dehydrogenase (LDH) cytotoxic assay. LPC induced the activation of THP-1-derived macrophages via calcium influx, and this activation was suppressed by potent and selective inhibitors of TRPA1. These results indicated that TRPA1 can mediate mtROS generation, mitochondrial membrane depolarization, the secretion of IL-1β and cytotoxicity through cellular and mitochondrial Ca2+ influx in LPC-treated THP-1-derived macrophages. Therefore, the inhibition of TRPA1 may protect THP-1-derived macrophages against LPC-induced injury.
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Affiliation(s)
- Chao Tian
- School of Life Sciences, University of Science and Technology of China, Hefei, Anhui, China.,Key Laboratory of Regenerative Biology, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, #190 Kai-Yuan Road, Guangzhou Science Park, Guangzhou, 510530, China.,Guangzhou Regenerative Medicine and Health Guangdong Laboratory, Guangzhou, Guangdong, China
| | - Rongqi Huang
- Key Laboratory of Regenerative Biology, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, #190 Kai-Yuan Road, Guangzhou Science Park, Guangzhou, 510530, China.,Guangzhou Regenerative Medicine and Health Guangdong Laboratory, Guangzhou, Guangdong, China
| | - Feng Tang
- Key Laboratory of Regenerative Biology, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, #190 Kai-Yuan Road, Guangzhou Science Park, Guangzhou, 510530, China.,Guangzhou Regenerative Medicine and Health Guangdong Laboratory, Guangzhou, Guangdong, China
| | - Zuoxian Lin
- Key Laboratory of Regenerative Biology, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, #190 Kai-Yuan Road, Guangzhou Science Park, Guangzhou, 510530, China.,Guangzhou Regenerative Medicine and Health Guangdong Laboratory, Guangzhou, Guangdong, China
| | - Na Cheng
- Key Laboratory of Regenerative Biology, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, #190 Kai-Yuan Road, Guangzhou Science Park, Guangzhou, 510530, China.,Guangzhou Regenerative Medicine and Health Guangdong Laboratory, Guangzhou, Guangdong, China.,Department of Anatomy and Neurobiology, School of Basic Medical Sciences, Central South University, Changsha, Hunan, China
| | - Xiaobo Han
- Key Laboratory of Regenerative Biology, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, #190 Kai-Yuan Road, Guangzhou Science Park, Guangzhou, 510530, China.,Guangzhou Regenerative Medicine and Health Guangdong Laboratory, Guangzhou, Guangdong, China
| | - Shuai Li
- Key Laboratory of Regenerative Biology, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, #190 Kai-Yuan Road, Guangzhou Science Park, Guangzhou, 510530, China.,Guangzhou Regenerative Medicine and Health Guangdong Laboratory, Guangzhou, Guangdong, China
| | - Peng Zhou
- Department of Anatomy and Neurobiology, School of Basic Medical Sciences, Central South University, Changsha, Hunan, China
| | - Sihao Deng
- Department of Anatomy and Neurobiology, School of Basic Medical Sciences, Central South University, Changsha, Hunan, China
| | - Hualin Huang
- Key Laboratory of Regenerative Biology, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, #190 Kai-Yuan Road, Guangzhou Science Park, Guangzhou, 510530, China.,Guangzhou Regenerative Medicine and Health Guangdong Laboratory, Guangzhou, Guangdong, China
| | - Huifang Zhao
- School of Life Sciences, University of Science and Technology of China, Hefei, Anhui, China.,Key Laboratory of Regenerative Biology, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, #190 Kai-Yuan Road, Guangzhou Science Park, Guangzhou, 510530, China.,Guangzhou Regenerative Medicine and Health Guangdong Laboratory, Guangzhou, Guangdong, China
| | - Junjie Xu
- Guangzhou JYK Biotechnology Company Limited, Guangzhou, Guangdong, China
| | - Zhiyuan Li
- School of Life Sciences, University of Science and Technology of China, Hefei, Anhui, China. .,Key Laboratory of Regenerative Biology, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, #190 Kai-Yuan Road, Guangzhou Science Park, Guangzhou, 510530, China. .,Guangzhou Regenerative Medicine and Health Guangdong Laboratory, Guangzhou, Guangdong, China. .,Department of Anatomy and Neurobiology, School of Basic Medical Sciences, Central South University, Changsha, Hunan, China. .,GZMU-GIBH Joint School of Life Sciences, Guangzhou Medical University, Guangzhou, Guangdong, China.
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31
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Foster JR, Ueno S, Chen MX, Harvey J, Dowell SJ, Irving AJ, Brown AJ. N-Palmitoylglycine and other N-acylamides activate the lipid receptor G2A/GPR132. Pharmacol Res Perspect 2019; 7:e00542. [PMID: 31768260 PMCID: PMC6868653 DOI: 10.1002/prp2.542] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2019] [Revised: 10/01/2019] [Accepted: 10/15/2019] [Indexed: 01/22/2023] Open
Abstract
The G-protein-coupled receptor GPR132, also known as G2A, is activated by 9-hydroxyoctadecadienoic acid (9-HODE) and other oxidized fatty acids. Other suggested GPR132 agonists including lysophosphatidylcholine (LPC) have not been readily reproduced. Here, we identify N-acylamides in particular N-acylglycines, as lipid activators of GPR132 with comparable activity to 9-HODE. The order-of-potency is N-palmitoylglycine > 9-HODE ≈ N-linoleoylglycine > linoleamide > N-oleoylglycine ≈ N-stereoylglycine > N-arachidonoylglycine > N-docosehexanoylglycine. Physiological concentrations of N-acylglycines in tissue are sufficient to activate GPR132. N-linoleoylglycine and 9-HODE also activate rat and mouse GPR132, despite limited sequence conservation to human. We describe pharmacological tools for GPR132, identified through drug screening. SKF-95667 is a novel GPR132 agonist. SB-583831 and SB-583355 are peptidomimetic molecules containing core amino acids (glycine and phenylalanine, respectively), and structurally related to previously described ligands. A telmisartan analog, GSK1820795A, antagonizes the actions of N-acylamides at GPR132. The synthetic cannabinoid CP-55 940 also activates GPR132. Molecular docking to a homology model suggested a site for lipid binding, predicting the acyl side-chain to extend into the membrane bilayer between TM4 and TM5 of GPR132. Small-molecule ligands are envisaged to occupy a "classical" site encapsulated in the 7TM bundle. Structure-directed mutagenesis indicates a critical role for arginine at position 203 in transmembrane domain 5 to mediate GPR132 activation by N-acylamides. Our data suggest distinct modes of binding for small-molecule and lipid agonists to the GPR132 receptor. Antagonists, such as those described here, will be vital to understand the physiological role of this long-studied target.
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Affiliation(s)
- James R. Foster
- GlaxoSmithKline R&D Ltd, Medicines Research CentreStevenageUK
- School of MedicineNinewells Hospital and Medical SchoolDundee UniversityDundeeUK
| | - Shohta Ueno
- GlaxoSmithKline R&D Ltd, Medicines Research CentreStevenageUK
- Present address:
RegeneronUxbridgeUK
| | - Mao Xiang Chen
- GlaxoSmithKline R&D Ltd, Medicines Research CentreStevenageUK
| | - Jenni Harvey
- School of MedicineNinewells Hospital and Medical SchoolDundee UniversityDundeeUK
| | - Simon J. Dowell
- GlaxoSmithKline R&D Ltd, Medicines Research CentreStevenageUK
| | - Andrew J. Irving
- School of Biomolecular and Biomedical ScienceThe Conway InstituteUniversity College DublinDublinIreland
| | - Andrew J. Brown
- GlaxoSmithKline R&D Ltd, Medicines Research CentreStevenageUK
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32
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Mashiko M, Kurosawa A, Tani Y, Tsuji T, Takeda S. GPR31 and GPR151 are activated under acidic conditions. J Biochem 2019; 166:317-322. [PMID: 31119277 DOI: 10.1093/jb/mvz042] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2019] [Accepted: 05/15/2019] [Indexed: 12/22/2022] Open
Abstract
Recent studies have revealed that not only proton-sensing channels, but also one family of G protein-coupled receptors (GPCRs) comprising OGR1, GPR4, G2A and TDAG8 are responsible for the sensing of extracellular protons, or pH. Here, we report that two other GPCRs, GPR31 and GPR151, were also activated in acidic condition. Elevated pH of assay mixtures resulted in a remarkable increase in [35S]GTPγS binding by GPR31-Giα and GPR151-Giα fusion proteins in a narrow range between pH 6 and 5. Our reporter gene assays with CHO cells expressing recombinant GPR31 or GPR151 also showed that activation was maximal at pH ∼5.8. Although these results from in vitro and cellular assays revealed slightly different pH sensitivities, all of our results indicated that GPR31 and GPR151 sensed extracellular protons equally well as other proton-sensing GPCRs.
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Affiliation(s)
- Misaki Mashiko
- Division of Molecular Science, Department of Chemical Biology, Faculty of Science and Technology, Gunma University, 1-5-1 Tenjin-cho, Kiryu, Gunma, Japan
| | - Aya Kurosawa
- Division of Molecular Science, Department of Chemical Biology, Faculty of Science and Technology, Gunma University, 1-5-1 Tenjin-cho, Kiryu, Gunma, Japan
| | - Yuki Tani
- Division of Molecular Science, Department of Chemical Biology, Faculty of Science and Technology, Gunma University, 1-5-1 Tenjin-cho, Kiryu, Gunma, Japan
| | - Takashi Tsuji
- Division of Molecular Science, Department of Chemical Biology, Faculty of Science and Technology, Gunma University, 1-5-1 Tenjin-cho, Kiryu, Gunma, Japan
| | - Shigeki Takeda
- Division of Molecular Science, Department of Chemical Biology, Faculty of Science and Technology, Gunma University, 1-5-1 Tenjin-cho, Kiryu, Gunma, Japan
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Lagadic-Gossmann D, Hardonnière K, Mograbi B, Sergent O, Huc L. Disturbances in H + dynamics during environmental carcinogenesis. Biochimie 2019; 163:171-183. [PMID: 31228544 DOI: 10.1016/j.biochi.2019.06.013] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2019] [Accepted: 06/16/2019] [Indexed: 12/24/2022]
Abstract
Despite the improvement of diagnostic methods and anticancer therapeutics, the human population is still facing an increasing incidence of several types of cancers. According to the World Health Organization, this growing trend would be partly linked to our environment, with around 20% of cancers stemming from exposure to environmental contaminants, notably chemicals like polycyclic aromatic hydrocarbons (PAHs). PAHs are widespread pollutants in our environment resulting from incomplete combustion or pyrolysis of organic material, and thus produced by both natural and anthropic sources; notably benzo[a]pyrene (B[a]P), i.e. the prototypical molecule of this family, that can be detected in cigarette smoke, diesel exhaust particles, occupational-related fumes, and grilled food. This molecule is a well-recognized carcinogen belonging to group 1 carcinogens. Indeed, it can target the different steps of the carcinogenic process and all cancer hallmarks. Interestingly, H+ dynamics have been described as key parameters for the occurrence of several, if not all, of these hallmarks. However, information regarding the role of such parameters during environmental carcinogenesis is still very scarce. The present review will thus mainly give an overview of the impact of B[a]P on H+ dynamics in liver cells, and will show how such alterations might impact different aspects related to the finely-tuned balance between cell death and survival processes, thereby likely favoring environmental carcinogenesis. In total, the main objective of this review is to encourage further research in this poorly explored field of environmental molecular toxicology.
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Affiliation(s)
- Dominique Lagadic-Gossmann
- Univ Rennes, Inserm, EHESP, Irset (Institut de recherche en santé, environnement et travail), UMR_S 1085, F-35000, Rennes, France.
| | - Kévin Hardonnière
- Univ Rennes, Inserm, EHESP, Irset (Institut de recherche en santé, environnement et travail), UMR_S 1085, F-35000, Rennes, France
| | - Baharia Mograbi
- Institute of Research on Cancer and Ageing of Nice (IRCAN), INSERM U1081, CNRS UMR7284, 2. Université de Nice-Sophia Antipolis, Faculté de Médecine, Centre Antoine Lacassagne, Nice, F-06107, France
| | - Odile Sergent
- Univ Rennes, Inserm, EHESP, Irset (Institut de recherche en santé, environnement et travail), UMR_S 1085, F-35000, Rennes, France
| | - Laurence Huc
- INRA, ToxAlim (Research Centre in Food Toxicology), Université de Toulouse, INRA, ENVT, INP-Purpan, UPS, Toulouse, France
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Glitsch M. Mechano- and pH-sensing convergence on Ca 2+-mobilising proteins - A recipe for cancer? Cell Calcium 2019; 80:38-45. [PMID: 30952068 DOI: 10.1016/j.ceca.2019.03.010] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2019] [Revised: 03/27/2019] [Accepted: 03/27/2019] [Indexed: 02/06/2023]
Abstract
Alterations in the (bio)chemical and physical microenvironment of cells accompany and often promote disease formation and progression. This is particularly well established for solid cancers, which are typically stiffer than the healthy tissue in which they arise, and often display profound acidification of their interstitial fluid. Cell surface receptors can sense changes in the mechanical and (bio)chemical properties of the surrounding extracellular matrix and fluid, and signalling through these receptors is thought to play a key role in disease development and advancement. This review will look at ion channels and G protein coupled receptors that are activated by mechanical cues and extracellular acidosis, and stimulation of which results in increases in intracellular Ca2+ concentrations. Cellular Ca2+ levels are dysregulated in cancer as well as cancer-associated cells, and mechano- and proton-sensing proteins likely contribute to these aberrant intracellular Ca2+ signals, making them attractive targets for therapeutic intervention.
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Affiliation(s)
- Maike Glitsch
- Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, UK.
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Tcymbarevich I, Richards SM, Russo G, Kühn-Georgijevic J, Cosin-Roger J, Baebler K, Lang S, Bengs S, Atrott K, Bettoni C, Gruber S, Frey-Wagner I, Scharl M, Misselwitz B, Wagner CA, Seuwen K, Rogler G, Ruiz PA, Spalinger M, de Vallière C. Lack of the pH-sensing Receptor TDAG8 [GPR65] in Macrophages Plays a Detrimental Role in Murine Models of Inflammatory Bowel Disease. J Crohns Colitis 2019; 13:245-258. [PMID: 30535144 DOI: 10.1093/ecco-jcc/jjy152] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
BACKGROUND Tissue inflammation in inflammatory bowel diseases [IBD] is associated with local acidification. Genetic variants in the pH-sensing G protein-coupled receptor 65, also known as T cell death-associated gene 8 [TDAG8], have been implicated in IBD and other autoimmune diseases. Since the role of TDAG8 in intestinal inflammation remains unclear, we investigated the function of TDAG8 using murine colitis models. METHODS The effects of TDAG8 deficiency were assessed in dextran sodium sulphate [DSS], IL-10-/-, and T cell transfer colitis murine models. RNA sequencing of acidosis-activated TDAG8-/- and wild-type [WT] peritoneal macrophages [MΦs] was performed. RESULTS mRNA expression of IFN-γ, TNF, IL-6, and iNOS in TDAG8-/- mice increased significantly in colonic lymphoid patches and in colonic tissue in acute and chronic DSS colitis, respectively. In transfer colitis, there was a trend towards increased IFN-γ, iNOS, and IL-6 expression in mice receiving TDAG8-/- T cells. However, absence of TDAG8 did not lead to changes in clinical scores in the models tested. Increased numbers of infiltrating MΦs and neutrophils, but not CD3+ T cells, were observed in DSS-treated TDAG8-/- mice. No differences in infiltrating CD3+ T cells were observed between mice receiving TDAG8-/- or WT naïve T cells in transfer colitis. RNA sequencing showed that acidosis activation of TDAG8 in MΦs modulated the expression of immune response genes. CONCLUSIONS TDAG8 deficiency triggers colonic MΦ and neutrophil infiltration, and expression of pro-inflammatory mediators in DSS colitis models. In transfer colitis, mice receiving TDAG8-/- T cells presented a significantly higher spleen weight and a tendency towards increased expression of pro-inflammatory markers of monocyte/MΦ activity.
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Affiliation(s)
- Irina Tcymbarevich
- Department of Gastroenterology and Hepatology, University Hospital Zürich, University of Zurich, Switzerland
| | | | - Giancarlo Russo
- Functional Genomics Center Zurich, ETH Zurich/University of Zurich, Zurich, Switzerland
| | | | - Jesus Cosin-Roger
- Department of Gastroenterology and Hepatology, University Hospital Zürich, University of Zurich, Switzerland
| | - Katharina Baebler
- Department of Gastroenterology and Hepatology, University Hospital Zürich, University of Zurich, Switzerland
| | - Silvia Lang
- Department of Gastroenterology and Hepatology, University Hospital Zürich, University of Zurich, Switzerland
| | - Susan Bengs
- Department of Gastroenterology and Hepatology, University Hospital Zürich, University of Zurich, Switzerland
| | - Kirstin Atrott
- Department of Gastroenterology and Hepatology, University Hospital Zürich, University of Zurich, Switzerland
| | - Carla Bettoni
- Institute of Physiology, University of Zurich, Switzerland
| | - Sven Gruber
- Department of Gastroenterology and Hepatology, University Hospital Zürich, University of Zurich, Switzerland.,Institute of Physiology, University of Zurich, Switzerland
| | - Isabelle Frey-Wagner
- Department of Gastroenterology and Hepatology, University Hospital Zürich, University of Zurich, Switzerland
| | - Michael Scharl
- Department of Gastroenterology and Hepatology, University Hospital Zürich, University of Zurich, Switzerland.,Zurich Center for Integrative Human Physiology, Zurich, Switzerland
| | - Benjamin Misselwitz
- Department of Gastroenterology and Hepatology, University Hospital Zürich, University of Zurich, Switzerland
| | - Carsten A Wagner
- Institute of Physiology, University of Zurich, Switzerland.,Zurich Center for Integrative Human Physiology, Zurich, Switzerland
| | - Klaus Seuwen
- Novartis Institutes for Biomedical Research, Basel, Switzerland
| | - Gerhard Rogler
- Department of Gastroenterology and Hepatology, University Hospital Zürich, University of Zurich, Switzerland.,Zurich Center for Integrative Human Physiology, Zurich, Switzerland
| | - Pedro A Ruiz
- Department of Gastroenterology and Hepatology, University Hospital Zürich, University of Zurich, Switzerland
| | - Marianne Spalinger
- Department of Gastroenterology and Hepatology, University Hospital Zürich, University of Zurich, Switzerland
| | - Cheryl de Vallière
- Department of Gastroenterology and Hepatology, University Hospital Zürich, University of Zurich, Switzerland
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Tcymbarevich IV, Eloranta JJ, Rossel JB, Obialo N, Spalinger M, Cosin-Roger J, Lang S, Kullak-Ublick GA, Wagner CA, Scharl M, Seuwen K, Ruiz PA, Rogler G, de Vallière C, Misselwitz B. The impact of the rs8005161 polymorphism on G protein-coupled receptor GPR65 (TDAG8) pH-associated activation in intestinal inflammation. BMC Gastroenterol 2019; 19:2. [PMID: 30616622 PMCID: PMC6323805 DOI: 10.1186/s12876-018-0922-8] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/07/2017] [Accepted: 12/20/2018] [Indexed: 12/15/2022] Open
Abstract
Background Tissue inflammation in inflammatory bowel diseases (IBD) is associated with a decrease in local pH. The gene encoding G-protein-coupled receptor 65 (GPR65) has recently been reported to be a genetic risk factor for IBD. In response to extracellular acidification, proton activation of GPR65 stimulates cAMP and Rho signalling pathways. We aimed to analyse the clinical and functional relevance of the GPR65 associated single nucleotide polymorphism (SNP) rs8005161. Methods 1138 individuals from a mixed cohort of IBD patients and healthy volunteers were genotyped for SNPs associated with GPR65 (rs8005161, rs3742704) and galactosylceramidase (rs1805078) by Taqman SNP assays. 2300 patients from the Swiss IBD Cohort Study (SIBDC) were genotyped for rs8005161 by mass spectrometry based SNP genotyping. IBD patients from the SIBDC carrying rs8005161 TT, CT, CC and non-IBD controls (CC) were recruited for functional studies. Human CD14+ cells were isolated from blood samples and subjected to an extracellular acidic pH shift, cAMP accumulation and RhoA activation were measured. Results In our mixed cohort, but not in SIBDC patients, the minor variant rs8005161 was significantly associated with UC. In SIBDC patients, we observed a consistent trend in increased disease severity in patients carrying the rs8005161-TT and rs8005161-CT alleles. No significant differences were observed in the pH associated activation of cAMP production between IBD (TT, CT, WT/CC) and non-IBD (WT/CC) genotype carriers upon an acidic extracellular pH shift. However, we observed significantly impaired RhoA activation after an extracellular acidic pH shift in IBD patients, irrespective of the rs8005161 allele. Conclusions The T allele of rs8005161 might confer a more severe disease course in IBD patients. Human monocytes from IBD patients showed impaired pH associated RhoA activation upon an acidic pH shift. Electronic supplementary material The online version of this article (10.1186/s12876-018-0922-8) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Irina V Tcymbarevich
- Department of Gastroenterology and Hepatology, University Hospital Zurich, University of Zurich, Zurich, Switzerland
| | - Jyrki J Eloranta
- Clinical Pharmacology and Toxicology, University Hospital Zurich, University of Zurich, Zurich, Switzerland
| | | | - Nicole Obialo
- Department of Gastroenterology and Hepatology, University Hospital Zurich, University of Zurich, Zurich, Switzerland
| | - Marianne Spalinger
- Department of Gastroenterology and Hepatology, University Hospital Zurich, University of Zurich, Zurich, Switzerland
| | - Jesus Cosin-Roger
- Department of Gastroenterology and Hepatology, University Hospital Zurich, University of Zurich, Zurich, Switzerland
| | - Silvia Lang
- Department of Gastroenterology and Hepatology, University Hospital Zurich, University of Zurich, Zurich, Switzerland
| | - Gerd A Kullak-Ublick
- Clinical Pharmacology and Toxicology, University Hospital Zurich, University of Zurich, Zurich, Switzerland
| | - Carsten A Wagner
- Institute of Physiology, University of Zurich, Zurich, Switzerland
| | - Michael Scharl
- Department of Gastroenterology and Hepatology, University Hospital Zurich, University of Zurich, Zurich, Switzerland
| | - Klaus Seuwen
- Novartis Institutes for Biomedical Research, Basel, Switzerland
| | - Pedro A Ruiz
- Department of Gastroenterology and Hepatology, University Hospital Zurich, University of Zurich, Zurich, Switzerland
| | - Gerhard Rogler
- Department of Gastroenterology and Hepatology, University Hospital Zurich, University of Zurich, Zurich, Switzerland
| | - Cheryl de Vallière
- Department of Gastroenterology and Hepatology, University Hospital Zurich, University of Zurich, Zurich, Switzerland.
| | - Benjamin Misselwitz
- Department of Gastroenterology and Hepatology, University Hospital Zurich, University of Zurich, Zurich, Switzerland. .,Present address: Department of Viceral Surgery and Medicine, Inselspital Bern and University of Bern, Freiburgstr. 18, 3010, Bern, Switzerland.
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Wei WC, Bianchi F, Wang YK, Tang MJ, Ye H, Glitsch MD. Coincidence Detection of Membrane Stretch and Extracellular pH by the Proton-Sensing Receptor OGR1 (GPR68). Curr Biol 2018; 28:3815-3823.e4. [PMID: 30471999 DOI: 10.1016/j.cub.2018.10.046] [Citation(s) in RCA: 41] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2018] [Revised: 09/05/2018] [Accepted: 10/19/2018] [Indexed: 12/24/2022]
Abstract
The physical environment critically affects cell shape, proliferation, differentiation, and survival by exerting mechanical forces on cells. These forces are sensed and transduced into intracellular signals and responses by cells. A number of different membrane and cytoplasmic proteins have been implicated in sensing mechanical forces, but the picture is far from complete, and the exact transduction pathways remain largely elusive. Furthermore, mechanosensation takes place alongside chemosensation, and cells need to integrate physical and chemical signals to respond appropriately and ensure normal tissue and organ development and function. Here, we report that ovarian cancer G protein coupled receptor 1 (OGR1) (aka GPR68) acts as coincidence detector of membrane stretch and its physiological ligand, extracellular H+. Using fluorescence imaging, substrates of different stiffness, microcontact printing methods, and cell-stretching techniques, we show that OGR1 only responds to extracellular acidification under conditions of membrane stretch and vice versa. The level of OGR1 activity mirrors the extent of membrane stretch and degree of extracellular acidification. Furthermore, actin polymerization in response to membrane stretch is critical for OGR1 activity, and its depolymerization limits how long OGR1 remains responsive following a stretch event, thus providing a "memory" for past stretch. Cells experience changes in membrane stretch and extracellular pH throughout their lifetime. Because OGR1 is a widely expressed receptor, it represents a unique yet widespread mechanism that enables cells to respond dynamically to mechanical and pH changes in their microenvironment by integrating these chemical and physical stimuli at the receptor level.
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Affiliation(s)
- Wei-Chun Wei
- Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford OX1 3PT, UK
| | - Fabio Bianchi
- Institute of Biomedical Engineering, Department of Engineering Science, University of Oxford, Oxford OX3 7DQ, UK
| | - Yang-Kao Wang
- Department of Cell Biology and Anatomy, College of Medicine, National Cheng Kung University, Tainan 70101, Taiwan
| | - Ming-Jer Tang
- Department of Physiology, College of Medicine and International Center for Wound Repair and Regeneration, National Cheng Kung University, Tainan 70101, Taiwan
| | - Hua Ye
- Institute of Biomedical Engineering, Department of Engineering Science, University of Oxford, Oxford OX3 7DQ, UK
| | - Maike D Glitsch
- Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford OX1 3PT, UK.
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Hutter S, van Haaften WT, Hünerwadel A, Baebler K, Herfarth N, Raselli T, Mamie C, Misselwitz B, Rogler G, Weder B, Dijkstra G, Meier CF, de Vallière C, Weber A, Imenez Silva PH, Wagner CA, Frey-Wagner I, Ruiz PA, Hausmann M. Intestinal Activation of pH-Sensing Receptor OGR1 [GPR68] Contributes to Fibrogenesis. J Crohns Colitis 2018; 12:1348-1358. [PMID: 30165600 DOI: 10.1093/ecco-jcc/jjy118] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
BACKGROUND AND AIMS pH-sensing ovarian cancer G-protein coupled receptor-1 [OGR1/GPR68] is regulated by key inflammatory cytokines. Patients suffering from inflammatory bowel diseases [IBDs] express increased mucosal levels of OGR1 compared with non-IBD controls. pH-sensing may be relevant for progression of fibrosis, as extracellular acidification leads to fibroblast activation and extracellular matrix remodelling. We aimed to determine OGR1 expression in fibrotic lesions in the intestine of Crohn's disease [CD] patients, and the effect of Ogr1 deficiency in fibrogenesis. METHODS Human fibrotic and non-fibrotic terminal ileum was obtained from CD patients undergoing ileocaecal resection due to stenosis. Gene expression of fibrosis markers and pH-sensing receptors was analysed. For the initiation of fibrosis in vivo, spontaneous colitis by Il10-/-, dextran sodium sulfate [DSS]-induced chronic colitis and the heterotopic intestinal transplantation model were used. RESULTS Increased expression of fibrosis markers was accompanied by an increase in OGR1 [2.71 ± 0.69 vs 1.18 ± 0.03, p = 0.016] in fibrosis-affected human terminal ileum, compared with the non-fibrotic resection margin. Positive correlation between OGR1 expression and pro-fibrotic cytokines [TGFB1 and CTGF] and pro-collagens was observed. The heterotopic animal model for intestinal fibrosis transplanted with terminal ileum from Ogr1-/- mice showed a decrease in mRNA expression of fibrosis markers as well as a decrease in collagen layer thickness and hydroxyproline compared with grafts from wild-type mice. CONCLUSIONS OGR1 expression was correlated with increased expression levels of pro-fibrotic genes and collagen deposition. Ogr1 deficiency was associated with a decrease in fibrosis formation. Targeting OGR1 may be a potential new treatment option for IBD-associated fibrosis.
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Affiliation(s)
- Senta Hutter
- Department of Gastroenterology and Hepatology, University Hospital Zürich, Zürich, Switzerland
| | - Wouter T van Haaften
- Department of Gastroenterology and Hepatology, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands.,Department of Pharmaceutical Technology and Biopharmacy, Groningen Research Institute of Pharmacy, University of Groningen, Groningen, The Netherlands
| | - Anouk Hünerwadel
- Department of Gastroenterology and Hepatology, University Hospital Zürich, Zürich, Switzerland
| | - Katharina Baebler
- Department of Gastroenterology and Hepatology, University Hospital Zürich, Zürich, Switzerland
| | - Neel Herfarth
- Department of Gastroenterology and Hepatology, University Hospital Zürich, Zürich, Switzerland
| | - Tina Raselli
- Department of Gastroenterology and Hepatology, University Hospital Zürich, Zürich, Switzerland
| | - Céline Mamie
- Department of Gastroenterology and Hepatology, University Hospital Zürich, Zürich, Switzerland
| | - Benjamin Misselwitz
- Department of Gastroenterology and Hepatology, University Hospital Zürich, Zürich, Switzerland
| | - Gerhard Rogler
- Department of Gastroenterology and Hepatology, University Hospital Zürich, Zürich, Switzerland.,Institute of Physiology, University of Zürich, Zürich, Switzerland
| | - Bruce Weder
- Department of Gastroenterology and Hepatology, University Hospital Zürich, Zürich, Switzerland
| | - Gerard Dijkstra
- Department of Gastroenterology and Hepatology, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands
| | - Chantal Florence Meier
- Department of Gastroenterology and Hepatology, University Hospital Zürich, Zürich, Switzerland
| | - Cheryl de Vallière
- Department of Gastroenterology and Hepatology, University Hospital Zürich, Zürich, Switzerland
| | - Achim Weber
- Department of Pathology and Molecular Pathology, University Hospital Zürich, Zürich, Switzerland
| | - Pedro H Imenez Silva
- Institute of Physiology, University of Zürich, Zürich, Switzerland.,Kidney Control of Homeostasis, Swiss National Centre of Competence in Research, Zürich, Switzerland
| | - Carsten A Wagner
- Institute of Physiology, University of Zürich, Zürich, Switzerland
| | - Isabelle Frey-Wagner
- Department of Gastroenterology and Hepatology, University Hospital Zürich, Zürich, Switzerland
| | - Pedro A Ruiz
- Department of Gastroenterology and Hepatology, University Hospital Zürich, Zürich, Switzerland
| | - Martin Hausmann
- Department of Gastroenterology and Hepatology, University Hospital Zürich, Zürich, Switzerland
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Specific oxylipins enhance vertebrate hematopoiesis via the receptor GPR132. Proc Natl Acad Sci U S A 2018; 115:9252-9257. [PMID: 30139917 DOI: 10.1073/pnas.1806077115] [Citation(s) in RCA: 37] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Epoxyeicosatrienoic acids (EETs) are lipid-derived signaling molecules with cardioprotective and vasodilatory actions. We recently showed that 11,12-EET enhances hematopoietic induction and engraftment in mice and zebrafish. EETs are known to signal via G protein-coupled receptors, with evidence supporting the existence of a specific high-affinity receptor. Identification of a hematopoietic-specific EET receptor would enable genetic interrogation of EET signaling pathways, and perhaps clinical use of this molecule. We developed a bioinformatic approach to identify an EET receptor based on the expression of G protein-coupled receptors in cell lines with differential responses to EETs. We found 10 candidate EET receptors that are expressed in three EET-responsive cell lines, but not expressed in an EET-unresponsive line. Of these, only recombinant GPR132 showed EET-responsiveness in vitro, using a luminescence-based β-arrestin recruitment assay. Knockdown of zebrafish gpr132b prevented EET-induced hematopoiesis, and marrow from GPR132 knockout mice showed decreased long-term engraftment capability. In contrast to high-affinity EET receptors, GPR132 is reported to respond to additional hydroxy-fatty acids in vitro, and we found that these same hydroxy-fatty acids enhance hematopoiesis in the zebrafish. We conducted structure-activity relationship analyses using both cell culture and zebrafish assays on diverse medium-chain fatty acids. Certain oxygenated, unsaturated free fatty acids showed high activation of GPR132, whereas unoxygenated or saturated fatty acids had lower activity. Absence of the carbon-1 position carboxylic acid prevented activity, suggesting that this moiety is required for receptor activation. GPR132 responds to a select panel of oxygenated polyunsaturated fatty acids to enhance both embryonic and adult hematopoiesis.
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Boedtkjer E. Acid-base regulation and sensing: Accelerators and brakes in metabolic regulation of cerebrovascular tone. J Cereb Blood Flow Metab 2018; 38:588-602. [PMID: 28984162 PMCID: PMC5888856 DOI: 10.1177/0271678x17733868] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/08/2017] [Revised: 08/10/2017] [Accepted: 09/06/2017] [Indexed: 12/29/2022]
Abstract
Metabolic regulation of cerebrovascular tone directs blood flow to areas of increased neuronal activity and during disease states partially compensates for insufficient perfusion by enhancing blood flow in collateral blood vessels. Acid-base disturbances frequently occur as result of enhanced metabolism or insufficient blood supply, but despite definitive evidence that acid-base disturbances alter arterial tone, effects of individual acid-base equivalents and the underlying signaling mechanisms are still being debated. H+ is an important intra- and extracellular messenger that modifies cerebrovascular tone. In addition, low extracellular [HCO3-] promotes cerebrovascular contraction through an endothelium-dependent mechanism. CO2 alters arterial tone development via changes in intra- and extracellular pH but it is still controversial whether CO2 also has direct vasomotor effects. Vasocontractile responses to low extracellular [HCO3-] and acute CO2-induced decreases in intracellular pH can counteract H+-mediated vasorelaxation during metabolic and respiratory acidosis, respectively, and may thereby reduce the risk of capillary damage and cerebral edema that could be consequences of unopposed vasodilation. In this review, the signaling mechanisms for acid-base equivalents in cerebral arteries and the mechanisms of intracellular pH control in the arterial wall are discussed in the context of metabolic regulation of cerebrovascular tone and local perfusion.
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Affiliation(s)
- Ebbe Boedtkjer
- Department of Biomedicine, Aarhus University, Aarhus, Denmark
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42
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Wang Y, de Vallière C, Imenez Silva PH, Leonardi I, Gruber S, Gerstgrasser A, Melhem H, Weber A, Leucht K, Wolfram L, Hausmann M, Krieg C, Thomasson K, Boyman O, Frey-Wagner I, Rogler G, Wagner CA. The Proton-activated Receptor GPR4 Modulates Intestinal Inflammation. J Crohns Colitis 2018; 12:355-368. [PMID: 29136128 DOI: 10.1093/ecco-jcc/jjx147] [Citation(s) in RCA: 54] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/25/2016] [Accepted: 11/02/2017] [Indexed: 12/12/2022]
Abstract
BACKGROUND AND AIMS During active inflammation, intraluminal intestinal pH is decreased in patients with inflammatory bowel disease [IBD]. Acidic pH may play a role in IBD pathophysiology. Recently, proton-sensing G-protein coupled receptors were identified, including GPR4, OGR1 [GPR68], and TDAG8 [GPR65]. We investigated whether GPR4 is involved in intestinal inflammation. METHODS The role of GPR4 was assessed in murine colitis models by chronic dextran sulphate sodium [DSS] administration and by cross-breeding into an IL-10 deficient background for development of spontaneous colitis. Colitis severity was assessed by body weight, colonoscopy, colon length, histological score, cytokine mRNA expression, and myeloperoxidase [MPO] activity. In the spontaneous Il-10-/- colitis model, the incidence of rectal prolapse and characteristics of lamina propria leukocytes [LPLs] were analysed. RESULTS Gpr4-/- mice showed reduced body weight loss and histology score after induction of chronic DSS colitis. In Gpr4-/-/Il-10-/- double knock-outs, the onset and progression of rectal prolapse were significantly delayed and mitigated compared with Gpr4+/+/Il-10-/- mice. Double knock-out mice showed lower histology scores, MPO activity, CD4+ T helper cell infiltration, IFN-γ, iNOS, MCP-1 [CCL2], CXCL1, and CXCL2 expression compared with controls. In colon, GPR4 mRNA was detected in endothelial cells, some smooth muscle cells, and some macrophages. CONCLUSIONS Absence of GPR4 ameliorates colitis in IBD animal models, indicating an important regulatory role in mucosal inflammation, thus providing a new link between tissue pH and the immune system. Therapeutic inhibition of GPR4 may be beneficial for the treatment of IBD.
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Affiliation(s)
- Yu Wang
- Department of Gastroenterology and Hepatology, University Hospital Zurich, Zurich, Switzerland.,Institute of Physiology, University of Zurich, Zurich, Switzerland
| | - Cheryl de Vallière
- Department of Gastroenterology and Hepatology, University Hospital Zurich, Zurich, Switzerland
| | | | - Irina Leonardi
- Department of Gastroenterology and Hepatology, University Hospital Zurich, Zurich, Switzerland
| | - Sven Gruber
- Department of Gastroenterology and Hepatology, University Hospital Zurich, Zurich, Switzerland.,Institute of Physiology, University of Zurich, Zurich, Switzerland
| | - Alexandra Gerstgrasser
- Department of Gastroenterology and Hepatology, University Hospital Zurich, Zurich, Switzerland
| | - Hassan Melhem
- Department of Gastroenterology and Hepatology, University Hospital Zurich, Zurich, Switzerland
| | - Achim Weber
- Institute of Surgical Pathology, University Hospital Zurich, Zurich, Switzerland
| | - Katharina Leucht
- Department of Gastroenterology and Hepatology, University Hospital Zurich, Zurich, Switzerland
| | - Lutz Wolfram
- Department of Gastroenterology and Hepatology, University Hospital Zurich, Zurich, Switzerland
| | - Martin Hausmann
- Department of Gastroenterology and Hepatology, University Hospital Zurich, Zurich, Switzerland
| | - Carsten Krieg
- Laboratory of Applied Immunobiology, University of Zurich, Zurich, Switzerland.,Institute of Experimental Immunology, University of Zurich, Zurich, Switzerland
| | - Koray Thomasson
- Laboratory of Applied Immunobiology, University of Zurich, Zurich, Switzerland
| | - Onur Boyman
- Laboratory of Applied Immunobiology, University of Zurich, Zurich, Switzerland.,Department of Immunology, University Hospital Zurich, University of Zurich, Zurich, Switzerland
| | - Isabelle Frey-Wagner
- Department of Gastroenterology and Hepatology, University Hospital Zurich, Zurich, Switzerland
| | - Gerhard Rogler
- Department of Gastroenterology and Hepatology, University Hospital Zurich, Zurich, Switzerland.,Institute of Physiology, University of Zurich, Zurich, Switzerland
| | - Carsten A Wagner
- Institute of Physiology, University of Zurich, Zurich, Switzerland
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43
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Weiß KT, Fante M, Köhl G, Schreml J, Haubner F, Kreutz M, Haverkampf S, Berneburg M, Schreml S. Proton-sensing G protein-coupled receptors as regulators of cell proliferation and migration during tumor growth and wound healing. Exp Dermatol 2018; 26:127-132. [PMID: 27623507 DOI: 10.1111/exd.13209] [Citation(s) in RCA: 41] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/06/2016] [Indexed: 12/20/2022]
Abstract
Dysregulation of pH is a feature of both tumor growth and tissue repair. In tumors, microenvironmental changes, like in lactate metabolism, lead to altered intra- and extracellular pH (pHi , pHe ) and vice versa. In wounds, barrier disruption results in extensive variations in pHe on the wound surface. It is known that altered extracellular proton concentrations have a major impact on cell turnover and migration as well as on the metabolic activity of cells involved in tumor spread and wound closure. The proton-sensing G protein-coupled receptors (GPCRs) GPR4, GPR65 (TDAG8), GPR68 (OGR1) and GPR132 (G2A) are activated via a decrease in pHe and transduce this signal to molecular intracellular pathways. Based on the current knowledge, we speculate on the role of proton-sensing GPCRs in wound healing and on their potential as mechanistic linkers of tumor growth and tissue repair.
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Affiliation(s)
- Katharina T Weiß
- Department of Dermatology, University Medical Center Regensburg, Regensburg, Germany
| | - Matthias Fante
- Department of Internal Medicine III, Oncology, University Medical Center Regensburg, Regensburg, Germany
| | - Gudrun Köhl
- Department of Surgery, University Medical Center Regensburg, Regensburg, Germany
| | - Julia Schreml
- Institute of Human Genetics, University of Cologne, Cologne, Germany
| | - Frank Haubner
- Department of Otorhinolaryngology, University Medical Center Regensburg, Regensburg, Germany
| | - Marina Kreutz
- Department of Internal Medicine III, Oncology, University Medical Center Regensburg, Regensburg, Germany
| | - Sonja Haverkampf
- Department of Dermatology, University Medical Center Regensburg, Regensburg, Germany
| | - Mark Berneburg
- Department of Dermatology, University Medical Center Regensburg, Regensburg, Germany
| | - Stephan Schreml
- Department of Dermatology, University Medical Center Regensburg, Regensburg, Germany
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44
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Miltz W, Velcicky J, Dawson J, Littlewood-Evans A, Ludwig MG, Seuwen K, Feifel R, Oberhauser B, Meyer A, Gabriel D, Nash M, Loetscher P. Design and synthesis of potent and orally active GPR4 antagonists with modulatory effects on nociception, inflammation, and angiogenesis. Bioorg Med Chem 2017; 25:4512-4525. [DOI: 10.1016/j.bmc.2017.06.050] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2017] [Revised: 06/26/2017] [Accepted: 06/28/2017] [Indexed: 10/19/2022]
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45
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Velcicky J, Miltz W, Oberhauser B, Orain D, Vaupel A, Weigand K, Dawson King J, Littlewood-Evans A, Nash M, Feifel R, Loetscher P. Development of Selective, Orally Active GPR4 Antagonists with Modulatory Effects on Nociception, Inflammation, and Angiogenesis. J Med Chem 2017; 60:3672-3683. [PMID: 28445047 DOI: 10.1021/acs.jmedchem.6b01703] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
A novel, selective, and efficacious GPR4 antagonist 13 was developed starting from lead compound 1a. While compound 1a showed promising efficacy in several disease models, its binding to a H3 receptor as well as a hERG channel prevented it from further development. Therefore, a new round of optimization addressing the key liabilities was performed and led to discovery of compound 13 with an improved profile. Compound 13 showed significant efficacy in the rat antigen induced arthritis as well as in the hyperalgesia and angiogenesis model at a well-tolerated dose of 30 mg/kg.
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Affiliation(s)
- Juraj Velcicky
- Global Discovery Chemistry, ‡Autoimmunity Transplantation Inflammation, §Musculoskeletal, ∥Metabolism and Pharmacokinetics, Novartis Institutes for BioMedical Research , CH-4002 Basel, Switzerland
| | - Wolfgang Miltz
- Global Discovery Chemistry, ‡Autoimmunity Transplantation Inflammation, §Musculoskeletal, ∥Metabolism and Pharmacokinetics, Novartis Institutes for BioMedical Research , CH-4002 Basel, Switzerland
| | - Berndt Oberhauser
- Global Discovery Chemistry, ‡Autoimmunity Transplantation Inflammation, §Musculoskeletal, ∥Metabolism and Pharmacokinetics, Novartis Institutes for BioMedical Research , CH-4002 Basel, Switzerland
| | - David Orain
- Global Discovery Chemistry, ‡Autoimmunity Transplantation Inflammation, §Musculoskeletal, ∥Metabolism and Pharmacokinetics, Novartis Institutes for BioMedical Research , CH-4002 Basel, Switzerland
| | - Andrea Vaupel
- Global Discovery Chemistry, ‡Autoimmunity Transplantation Inflammation, §Musculoskeletal, ∥Metabolism and Pharmacokinetics, Novartis Institutes for BioMedical Research , CH-4002 Basel, Switzerland
| | - Klaus Weigand
- Global Discovery Chemistry, ‡Autoimmunity Transplantation Inflammation, §Musculoskeletal, ∥Metabolism and Pharmacokinetics, Novartis Institutes for BioMedical Research , CH-4002 Basel, Switzerland
| | - Janet Dawson King
- Global Discovery Chemistry, ‡Autoimmunity Transplantation Inflammation, §Musculoskeletal, ∥Metabolism and Pharmacokinetics, Novartis Institutes for BioMedical Research , CH-4002 Basel, Switzerland
| | - Amanda Littlewood-Evans
- Global Discovery Chemistry, ‡Autoimmunity Transplantation Inflammation, §Musculoskeletal, ∥Metabolism and Pharmacokinetics, Novartis Institutes for BioMedical Research , CH-4002 Basel, Switzerland
| | - Mark Nash
- Global Discovery Chemistry, ‡Autoimmunity Transplantation Inflammation, §Musculoskeletal, ∥Metabolism and Pharmacokinetics, Novartis Institutes for BioMedical Research , CH-4002 Basel, Switzerland
| | - Roland Feifel
- Global Discovery Chemistry, ‡Autoimmunity Transplantation Inflammation, §Musculoskeletal, ∥Metabolism and Pharmacokinetics, Novartis Institutes for BioMedical Research , CH-4002 Basel, Switzerland
| | - Pius Loetscher
- Global Discovery Chemistry, ‡Autoimmunity Transplantation Inflammation, §Musculoskeletal, ∥Metabolism and Pharmacokinetics, Novartis Institutes for BioMedical Research , CH-4002 Basel, Switzerland
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46
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Ross T, Jakubzig B, Grundmann M, Massing U, Kostenis E, Schlesinger M, Bendas G. The molecular mechanism by which saturated lysophosphatidylcholine attenuates the metastatic capacity of melanoma cells. FEBS Open Bio 2016; 6:1297-1309. [PMID: 28255537 PMCID: PMC5324772 DOI: 10.1002/2211-5463.12152] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2016] [Revised: 10/13/2016] [Accepted: 10/25/2016] [Indexed: 12/11/2022] Open
Abstract
Lysophophatidylcholine (LysoPC) is an abundant constituent in human plasma. Patients with malignant cancer diseases have attenuated LysoPC plasma levels, and thus LysoPC has been examined as a metabolic biomarker for cancer prediction. Preclinical studies have shown that solid tumor cells drastically degrade LysoPCs by incorporating their free fatty acids into cell membrane phospholipids. In this way, LysoPC C18:0 reduced the metastatic spread of murine melanoma B16.F10 cells in mice. Although membrane rigidification may have a key role in the attenuation of metastasis, evidence for this has yet to be shown. Therefore, the present study aimed to determine how LysoPC reduces the metastatic capacity of B16.F10 cells. Following cellular preincubation with LysoPC C18:0 at increasing concentrations and lengths of time, cell migration was most significantly attenuated with 450 μm LysoPC C18:0 at 72 h. Biosensor measurements suggest that, despite their abundance in B16.F10 cells, LysoPC‐sensitive G protein‐coupled receptors do not appear to contribute to this effect. Instead, the attenuated migration appears to result from changes in cell membrane properties and their effect on underlying signaling pathways, most likely the formation of focal adhesion complexes. Treatment with 450 μm LysoPC C18:0 activates protein kinase C (PKC)δ to phosphorylate syndecan‐4, accompanied by deactivation of PKCα. Subsequently, focal adhesion complex formation was attenuated, as confirmed by the reduced activity of focal adhesion kinase (FAK). Interestingly, 450 μm LysoPC C18:1 did not affect FAK activity, explaining its lower propensity to affect migration and metastasis. Therefore, membrane rigidification by LysoPC C18:0 appears to prevent the formation of focal adhesion complexes, thus affecting integrin activity as a key for metastatic melanoma spread.
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Affiliation(s)
- Thomas Ross
- Department of Pharmaceutical Chemistry II University of Bonn Germany
| | - Bastian Jakubzig
- Department of Pharmaceutical Chemistry II University of Bonn Germany
| | | | - Ulrich Massing
- Andreas Hettich GmbH & Co. KGF&E Lifescience Applications Freiburg Germany; Faculty of Chemistry & Pharmacy University of Freiburg Germany
| | - Evi Kostenis
- Department of Pharmaceutical Biology University of Bonn Germany
| | | | - Gerd Bendas
- Department of Pharmaceutical Chemistry II University of Bonn Germany
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47
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de Vallière C, Cosin-Roger J, Simmen S, Atrott K, Melhem H, Zeitz J, Madanchi M, Tcymbarevich I, Fried M, Kullak-Ublick GA, Vavricka SR, Misselwitz B, Seuwen K, Wagner CA, Eloranta JJ, Rogler G, Ruiz PA. Hypoxia Positively Regulates the Expression of pH-Sensing G-Protein-Coupled Receptor OGR1 (GPR68). Cell Mol Gastroenterol Hepatol 2016; 2:796-810. [PMID: 28174749 PMCID: PMC5247318 DOI: 10.1016/j.jcmgh.2016.06.003] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/04/2016] [Accepted: 06/17/2016] [Indexed: 12/11/2022]
Abstract
BACKGROUND & AIMS A novel family of proton-sensing G-protein-coupled receptors, including ovarian cancer G-protein-coupled receptor 1 (OGR1) (GPR68) has been identified to play a role in pH homeostasis. Hypoxia is known to change tissue pH as a result of anaerobic glucose metabolism through the stabilization of hypoxia-inducible factor-1α. We investigated how hypoxia regulates the expression of OGR1 in the intestinal mucosa and associated cells. METHODS OGR1 expression in murine tumors, human colonic tissue, and myeloid cells was determined by quantitative reverse-transcription polymerase chain reaction. The influence of hypoxia on OGR1 expression was studied in monocytes/macrophages and intestinal mucosa of inflammatory bowel disease (IBD) patients. Changes in OGR1 expression in MonoMac6 (MM6) cells under hypoxia were determined upon stimulation with tumor necrosis factor (TNF), in the presence or absence of nuclear factor-κB (NF-κB) inhibitors. To study the molecular mechanisms involved, chromatin immunoprecipitation analysis of the OGR1 promoter was performed. RESULTS OGR1 expression was significantly higher in tumor tissue compared with normal murine colon tissue. Hypoxia positively regulated the expression of OGR1 in MM6 cells, mouse peritoneal macrophages, primary human intestinal macrophages, and colonic tissue from IBD patients. In MM6 cells, hypoxia-enhanced TNF-induced OGR1 expression was reversed by inhibition of NF-κB. In addition to the effect of TNF and hypoxia, OGR1 expression was increased further at low pH. Chromatin immunoprecipitation analysis showed that HIF-1α, but not NF-κB, binds to the promoter of OGR1 under hypoxia. CONCLUSIONS The enhancement of TNF- and hypoxia-induced OGR1 expression under low pH points to a positive feed-forward regulation of OGR1 activity in acidic conditions, and supports a role for OGR1 in the pathogenesis of IBD.
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Key Words
- AICAR, 5-aminoimidazole-4-carboxamide-1-β-4-ribofuranoside
- CD, Crohn's disease
- ChIP, chromatin immunoprecipitation
- FCS, fetal calf serum
- GPR, G-protein–coupled receptor
- GRP65
- HIF, hypoxia-inducible factor
- HV, healthy volunteer
- IBD, inflammatory bowel disease
- IEC, intestinal epithelial cell
- IFN, interferon
- IL, interleukin
- Inflammation
- Inflammatory Bowel Disease
- MM6, MonoMac 6
- NF-κB, nuclear factor-κB
- OGR1, ovarian cancer G-protein–coupled receptor 1 (GPR68)
- Ovarian Cancer G-Protein–Coupled Receptor
- RT-qPCR, quantitative reverse-transcription polymerase chain reaction
- SPARC, secreted protein acidic and rich in cysteine
- TDAG8
- TDAG8, T-cell death-associated gene 8 (GPR65)
- TNF, tumor necrosis factor
- Th, T-helper
- UC, ulcerative colitis
- WT, wild type
- mRNA, messenger RNA
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Affiliation(s)
- Cheryl de Vallière
- Division of Gastroenterology and Hepatology, University Hospital Zurich, Zurich, Switzerland
| | - Jesus Cosin-Roger
- Division of Gastroenterology and Hepatology, University Hospital Zurich, Zurich, Switzerland; Department of Pharmacology and Biomedical Research Networking Center in Hepatic and Digestive Diseases (CIBERehd), Faculty of Medicine, University of Valencia, Valencia, Spain
| | - Simona Simmen
- Division of Gastroenterology and Hepatology, University Hospital Zurich, Zurich, Switzerland
| | - Kirstin Atrott
- Division of Gastroenterology and Hepatology, University Hospital Zurich, Zurich, Switzerland
| | - Hassan Melhem
- Division of Gastroenterology and Hepatology, University Hospital Zurich, Zurich, Switzerland
| | - Jonas Zeitz
- Division of Gastroenterology and Hepatology, University Hospital Zurich, Zurich, Switzerland
| | - Mehdi Madanchi
- Division of Gastroenterology and Hepatology, University Hospital Zurich, Zurich, Switzerland
| | - Irina Tcymbarevich
- Division of Gastroenterology and Hepatology, University Hospital Zurich, Zurich, Switzerland
| | - Michael Fried
- Division of Gastroenterology and Hepatology, University Hospital Zurich, Zurich, Switzerland
| | - Gerd A Kullak-Ublick
- Department of Clinical Pharmacology and Toxicology, University Hospital Zurich, Zurich, Switzerland
| | - Stephan R Vavricka
- Division of Gastroenterology and Hepatology, University Hospital Zurich, Zurich, Switzerland
| | - Benjamin Misselwitz
- Division of Gastroenterology and Hepatology, University Hospital Zurich, Zurich, Switzerland
| | - Klaus Seuwen
- Novartis Institutes for Biomedical Research, Basel, Switzerland
| | - Carsten A Wagner
- Institute of Physiology, University Hospital Zurich, Zurich, Switzerland
| | - Jyrki J Eloranta
- Department of Clinical Pharmacology and Toxicology, University Hospital Zurich, Zurich, Switzerland
| | - Gerhard Rogler
- Division of Gastroenterology and Hepatology, University Hospital Zurich, Zurich, Switzerland
| | - Pedro A Ruiz
- Division of Gastroenterology and Hepatology, University Hospital Zurich, Zurich, Switzerland
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48
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Pera T, Penn RB. Bronchoprotection and bronchorelaxation in asthma: New targets, and new ways to target the old ones. Pharmacol Ther 2016; 164:82-96. [PMID: 27113408 PMCID: PMC4942340 DOI: 10.1016/j.pharmthera.2016.04.002] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2016] [Accepted: 04/07/2016] [Indexed: 01/01/2023]
Abstract
Despite over 50years of inhaled beta-agonists and corticosteroids as the default management or rescue drugs for asthma, recent research suggests that new therapeutic options are likely to emerge. This belief stems from both an improved understanding of what causes and regulates airway smooth muscle (ASM) contraction, and the identification of new targets whose inhibition or activation can relax ASM. In this review we discuss the recent findings that provide new insight into ASM contractile regulation, a revolution in pharmacology that identifies new ways to "tune" G protein-coupled receptors to improve therapeutic efficacy, and the discovery of several novel targets/approaches capable of effecting bronchoprotection or bronchodilation.
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Affiliation(s)
- Tonio Pera
- Center for Translational Medicine and Jane and Leonard Korman Lung Center, Sidney Kimmel Medical College, Thomas Jefferson University, Philadelphia, PA, United States.
| | - Raymond B Penn
- Center for Translational Medicine and Jane and Leonard Korman Lung Center, Sidney Kimmel Medical College, Thomas Jefferson University, Philadelphia, PA, United States.
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49
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Boedtkjer E, Hansen KB, Boedtkjer DMB, Aalkjaer C, Boron WF. Extracellular HCO3- is sensed by mouse cerebral arteries: Regulation of tone by receptor protein tyrosine phosphatase γ. J Cereb Blood Flow Metab 2016; 36:965-80. [PMID: 26661205 PMCID: PMC4853837 DOI: 10.1177/0271678x15610787] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/27/2015] [Accepted: 09/15/2015] [Indexed: 11/15/2022]
Abstract
We investigate sensing and signaling mechanisms for H(+), [Formula: see text] and CO2 in basilar arteries using out-of-equilibrium solutions. Selectively varying pHo, [[Formula: see text]]o, or pCO2, we find: (a) lowering pHo attenuates vasoconstriction and vascular smooth muscle cell (VSMC) Ca(2+)-responses whereas raising pHo augments vasoconstriction independently of VSMC [Ca(2+)]i, (b) lowering [[Formula: see text]]o increases arterial agonist-sensitivity of tone development without affecting VSMC [Ca(2+)]i but c) no evidence that CO2 has direct net vasomotor effects. Receptor protein tyrosine phosphatase (RPTP)γ is transcribed in endothelial cells, and direct vasomotor effects of [Formula: see text] are absent in arteries from RPTPγ-knockout mice. At pHo 7.4, selective changes in [[Formula: see text]]o or pCO2 have little effect on pHi At pHo 7.1, decreased [[Formula: see text]]o or increased pCO2 causes intracellular acidification, which attenuates vasoconstriction. Under equilibrated conditions, anti-contractile effects of CO2/[Formula: see text] are endothelium-dependent and absent in arteries from RPTPγ-knockout mice. With CO2/[Formula: see text] present, contractile responses to agonist-stimulation are potentiated in arteries from RPTPγ-knockout compared to wild-type mice, and this difference is larger for respiratory than metabolic acidosis. In conclusion, decreased pHo and pHi inhibit vasoconstriction, whereas decreased [[Formula: see text]]o promotes vasoconstriction through RPTPγ-dependent changes in VSMC Ca(2+)-sensitivity. [Formula: see text] serves dual roles, providing substrate for pHi-regulating membrane transporters and modulating arterial responses to acid-base disturbances.
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Affiliation(s)
- Ebbe Boedtkjer
- Department of Biomedicine, Aarhus University, Aarhus, Denmark Department of Physiology and Biophysics, Case Western Reserve University, Cleveland, OH, USA
| | | | - Donna M B Boedtkjer
- Department of Biomedicine, Aarhus University, Aarhus, Denmark Department of Physiology and Biophysics, Case Western Reserve University, Cleveland, OH, USA
| | | | - Walter F Boron
- Department of Physiology and Biophysics, Case Western Reserve University, Cleveland, OH, USA
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50
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D’Souza CA, Zhao FL, Li X, Xu Y, Dunn SE, Zhang L. OGR1/GPR68 Modulates the Severity of Experimental Autoimmune Encephalomyelitis and Regulates Nitric Oxide Production by Macrophages. PLoS One 2016; 11:e0148439. [PMID: 26828924 PMCID: PMC4735495 DOI: 10.1371/journal.pone.0148439] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2015] [Accepted: 01/18/2016] [Indexed: 11/18/2022] Open
Abstract
Ovarian cancer G protein-coupled receptor 1 (OGR1) is a proton-sensing molecule that can detect decreases in extracellular pH that occur during inflammation. Although OGR1 has been shown to have pro-inflammatory functions in various diseases, its role in autoimmunity has not been examined. We therefore sought to determine whether OGR1 has a role in the development of T cell autoimmunity by contrasting the development of experimental autoimmune encephalomyelitis between wild type and OGR1-knockout mice. OGR1-knockout mice showed a drastically attenuated clinical course of disease that was associated with a profound reduction in the expansion of myelin oligodendrocyte glycoprotein 35-55-reactive T helper 1 (Th1) and Th17 cells in the periphery and a reduced accumulation of Th1 and Th17 effectors in the central nervous system. We determined that these impaired T cell responses in OGR1-knockout mice associated with a reduced frequency and number of dendritic cells in draining lymph nodes during EAE and a higher production of nitric oxide by macrophages. Our studies suggest that OGR1 plays a key role in regulating T cell responses during autoimmunity.
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Affiliation(s)
- Cheryl A. D’Souza
- Toronto General Research Institute, University Health Network, Toronto, Ontario, Canada
| | - Fei Linda Zhao
- Department of Immunology, University of Toronto, Toronto, Ontario, Canada
| | - Xujian Li
- Toronto General Research Institute, University Health Network, Toronto, Ontario, Canada
| | - Yan Xu
- Department of Obstetrics and Gynecology, Indiana University School of Medicine, Indianapolis, Indiana, United States of America
| | - Shannon E. Dunn
- Toronto General Research Institute, University Health Network, Toronto, Ontario, Canada
- Department of Immunology, University of Toronto, Toronto, Ontario, Canada
- Women’s College Research Institute, Toronto, Ontario, Canada
- * E-mail: (LZ); (SED)
| | - Li Zhang
- Toronto General Research Institute, University Health Network, Toronto, Ontario, Canada
- Department of Immunology, University of Toronto, Toronto, Ontario, Canada
- Department of Laboratory Medicine and Pathobiology and Immunology, University of Toronto, Toronto, Ontario, Canada
- * E-mail: (LZ); (SED)
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