1
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Becker HM, Seidler UE. Bicarbonate secretion and acid/base sensing by the intestine. Pflugers Arch 2024; 476:593-610. [PMID: 38374228 PMCID: PMC11006743 DOI: 10.1007/s00424-024-02914-3] [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: 11/16/2023] [Revised: 01/15/2024] [Accepted: 01/17/2024] [Indexed: 02/21/2024]
Abstract
The transport of bicarbonate across the enterocyte cell membrane regulates the intracellular as well as the luminal pH and is an essential part of directional fluid movement in the gut. Since the first description of "active" transport of HCO3- ions against a concentration gradient in the 1970s, the fundamental role of HCO3- transport for multiple intestinal functions has been recognized. The ion transport proteins have been identified and molecularly characterized, and knockout mouse models have given insight into their individual role in a variety of functions. This review describes the progress made in the last decade regarding novel techniques and new findings in the molecular regulation of intestinal HCO3- transport in the different segments of the gut. We discuss human diseases with defects in intestinal HCO3- secretion and potential treatment strategies to increase luminal alkalinity. In the last part of the review, the cellular and organismal mechanisms for acid/base sensing in the intestinal tract are highlighted.
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Affiliation(s)
- Holger M Becker
- Department of Gastroenterology, Hannover Medical School, 30625, Hannover, Germany
| | - Ursula E Seidler
- Department of Gastroenterology, Hannover Medical School, 30625, Hannover, Germany.
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2
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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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3
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Khan NM, Diaz-Hernandez ME, Martin WN, Patel B, Chihab S, Drissi H. pH-sensing G protein-coupled orphan receptor GPR68 is expressed in human cartilage and correlates with degradation of extracellular matrix during OA progression. PeerJ 2023; 11:e16553. [PMID: 38077417 PMCID: PMC10704986 DOI: 10.7717/peerj.16553] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2023] [Accepted: 11/09/2023] [Indexed: 12/18/2023] Open
Abstract
Background Osteoarthritis (OA) is a debilitating joints disease affecting millions of people worldwide. As OA progresses, chondrocytes experience heightened catabolic activity, often accompanied by alterations in the extracellular environment's osmolarity and acidity. Nevertheless, the precise mechanism by which chondrocytes perceive and respond to acidic stress remains unknown. Recently, there has been growing interest in pH-sensing G protein-coupled receptors (GPCRs), such as GPR68, within musculoskeletal tissues. However, function of GPR68 in cartilage during OA progression remains unknown. This study aims to identify the role of GPR68 in regulation of catabolic gene expression utilizing an in vitro model that simulates catabolic processes in OA. Methods We examined the expression of GPCR by analyzing high throughput RNA-Seq data in human cartilage isolated from healthy donors and OA patients. De-identified and discarded OA cartilage was obtained from joint arthroplasty and chondrocytes were prepared by enzymatic digestion. Chondrocytes were treated with GPR68 agonist, Ogerin and then stimulated IL1β and RNA isolation was performed using Trizol method. Reverse transcription was done using the cDNA synthesis kit and the expression of GPR68 and OA related catabolic genes was quantified using SYBR® green assays. Results The transcriptome analysis revealed that pH sensing GPCR were expressed in human cartilage with a notable increase in the expression of GPR68 in OA cartilage which suggest a potential role for GPR68 in the pathogenesis of OA. Immunohistochemical (IHC) and qPCR analyses in human cartilage representing various stages of OA indicated a progressive increase in GPR68 expression in cartilage associated with higher OA grades, underscoring a correlation between GPR68 expression and the severity of OA. Furthermore, IHC analysis of Gpr68 in murine cartilage subjected to surgically induced OA demonstrated elevated levels of GPR68 in knee cartilage and meniscus. Using IL1β stimulated in vitro model of OA catabolism, our qPCR analysis unveiled a time-dependent increase in GPR68 expression in response to IL1β stimulation, which correlates with the expression of matrix degrading proteases suggesting the role of GPR68 in chondrocytes catabolism and matrix degeneration. Using pharmacological activator of GPR68, our results further showed that GPR68 activation repressed the expression of MMPs in human chondrocytes. Conclusions Our results demonstrated that GPR68 was robustly expressed in human cartilage and mice and its expression correlates with matrix degeneration and severity of OA progression in human and surgical model. GPR68 activation in human chondrocytes further repressed the expression of MMPs under OA pathological condition. These results identify GPR68 as a possible therapeutic target in the regulation of matrix degradation during OA.
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Affiliation(s)
- Nazir M. Khan
- Orthopaedics, Emory University, Atlanta, GA, United States
| | | | | | - Bhakti Patel
- Orthopaedics, Emory University, Atlanta, GA, United States
| | - Samir Chihab
- Orthopaedics, Emory University, Atlanta, GA, United States
| | - Hicham Drissi
- Orthopaedics, Emory University, Atlanta, GA, United States
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4
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Shore D, Griggs N, Graffeo V, Amin ARMR, Zha XM, Xu Y, McAleer JP. GPR68 limits the severity of chemical-induced oral epithelial dysplasia. Sci Rep 2023; 13:353. [PMID: 36611126 PMCID: PMC9825365 DOI: 10.1038/s41598-023-27546-y] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2022] [Accepted: 01/04/2023] [Indexed: 01/09/2023] Open
Abstract
Head and neck cancer is the sixth most common malignancy, and there is an urgent need to identify physiological processes contributing to tumorigenesis. Extracellular acidification caused by aerobic glycolysis within tumor microenvironments can stimulate proton-sensing receptors. GPR68, or ovarian cancer G protein-coupled receptor 1, responds to extracellular acidity and is highly expressed in head and neck squamous cell carcinoma (HNSCC) as well as normal esophageal tissue. To study the role of GPR68 in oral dysplasia, wild-type and GPR68-/- mice were treated with 4-Nitroquinoline N-oxide (4NQO) in drinking water for 11-13 weeks, followed by normal water for 11-12 weeks. 4NQO treatment resulted in 45 percent of GPR68-/- mice developing severe dysplasia or squamous cell carcinoma compared to only 10.5 percent of GPR68+/+ mice. This correlated with increased frequencies of regulatory T cells in the spleens of male GPR68-/- mice. Dysplastic regions of the tongue had increased CD31 staining compared to normal regions in both GPR68-/- and GPR68+/+ mice, suggesting that angiogenesis was GPR68-independent. RNA knockdown studies using HNSCC cell lines demonstrated no direct effect of GPR68 on survival or growth. Overall, we demonstrate that GPR68-deficiency worsens the severity of chemical-induced oral dysplasia, suggesting a protective role for this gene in tumorigenesis.
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Affiliation(s)
- David Shore
- grid.259676.90000 0001 2214 9920Marshall University School of Pharmacy, Huntington, WV USA
| | - Nosakhere Griggs
- grid.259676.90000 0001 2214 9920Marshall University School of Pharmacy, Huntington, WV USA
| | - Vincent Graffeo
- grid.36425.360000 0001 2216 9681Marshall University Joan C. Edwards School of Medicine, Huntington, WV USA
| | - A. R. M. Ruhul Amin
- grid.259676.90000 0001 2214 9920Marshall University School of Pharmacy, Huntington, WV USA
| | - Xiang-ming Zha
- grid.266756.60000 0001 2179 926XUniversity of Missouri-Kansas City School of Pharmacy, Kansas City, MO USA
| | - Yan Xu
- grid.257413.60000 0001 2287 3919Indiana University School of Medicine, Indianapolis, IN USA
| | - Jeremy P. McAleer
- grid.259676.90000 0001 2214 9920Marshall University School of Pharmacy, Huntington, WV USA
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5
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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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6
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Chen X, Jaiswal A, Costliow Z, Herbst P, Creasey EA, Oshiro-Rapley N, Daly MJ, Carey KL, Graham DB, Xavier RJ. pH sensing controls tissue inflammation by modulating cellular metabolism and endo-lysosomal function of immune cells. Nat Immunol 2022; 23:1063-1075. [PMID: 35668320 PMCID: PMC9720675 DOI: 10.1038/s41590-022-01231-0] [Citation(s) in RCA: 24] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2021] [Accepted: 04/26/2022] [Indexed: 02/08/2023]
Abstract
Extracellular acidification occurs in inflamed tissue and the tumor microenvironment; however, a systematic study on how pH sensing contributes to tissue homeostasis is lacking. In the present study, we examine cell type-specific roles of the pH sensor G protein-coupled receptor 65 (GPR65) and its inflammatory disease-associated Ile231Leu-coding variant in inflammation control. GPR65 Ile231Leu knock-in mice are highly susceptible to both bacterial infection-induced and T cell-driven colitis. Mechanistically, GPR65 Ile231Leu elicits a cytokine imbalance through impaired helper type 17 T cell (TH17 cell) and TH22 cell differentiation and interleukin (IL)-22 production in association with altered cellular metabolism controlled through the cAMP-CREB-DGAT1 axis. In dendritic cells, GPR65 Ile231Leu elevates IL-12 and IL-23 release at acidic pH and alters endo-lysosomal fusion and degradation capacity, resulting in enhanced antigen presentation. The present study highlights GPR65 Ile231Leu as a multistep risk factor in intestinal inflammation and illuminates a mechanism by which pH sensing controls inflammatory circuits and tissue homeostasis.
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Affiliation(s)
- Xiangjun Chen
- Broad Institute of MIT and Harvard, Cambridge, MA, USA
- Center for Computational and Integrative Biology, Massachusetts General Hospital, Boston, MA, USA
- Department of Molecular Biology, Massachusetts General Hospital, Boston, MA, USA
- Experimental Medicine Unit, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
| | - Alok Jaiswal
- Broad Institute of MIT and Harvard, Cambridge, MA, USA
| | | | - Paula Herbst
- Center for Computational and Integrative Biology, Massachusetts General Hospital, Boston, MA, USA
- Department of Molecular Biology, Massachusetts General Hospital, Boston, MA, USA
| | - Elizabeth A Creasey
- Broad Institute of MIT and Harvard, Cambridge, MA, USA
- Center for Computational and Integrative Biology, Massachusetts General Hospital, Boston, MA, USA
- Department of Molecular Biology, Massachusetts General Hospital, Boston, MA, USA
| | - Noriko Oshiro-Rapley
- Broad Institute of MIT and Harvard, Cambridge, MA, USA
- Center for Computational and Integrative Biology, Massachusetts General Hospital, Boston, MA, USA
- Department of Molecular Biology, Massachusetts General Hospital, Boston, MA, USA
- Experimental Medicine Unit, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
| | - Mark J Daly
- Broad Institute of MIT and Harvard, Cambridge, MA, USA
- Analytic and Translational Genetics Unit, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
- Institute for Molecular Medicine Finland, Helsinki, Finland
| | | | - Daniel B Graham
- Broad Institute of MIT and Harvard, Cambridge, MA, USA
- Center for Computational and Integrative Biology, Massachusetts General Hospital, Boston, MA, USA
- Department of Molecular Biology, Massachusetts General Hospital, Boston, MA, USA
- Experimental Medicine Unit, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
- Klarman Cell Observatory, Broad Institute of MIT and Harvard, Cambridge, MA, USA
| | - Ramnik J Xavier
- Broad Institute of MIT and Harvard, Cambridge, MA, USA.
- Center for Computational and Integrative Biology, Massachusetts General Hospital, Boston, MA, USA.
- Department of Molecular Biology, Massachusetts General Hospital, Boston, MA, USA.
- Klarman Cell Observatory, Broad Institute of MIT and Harvard, Cambridge, MA, USA.
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7
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Imenez Silva PH, Câmara NO, Wagner CA. Role of proton-activated G protein-coupled receptors in pathophysiology. Am J Physiol Cell Physiol 2022; 323:C400-C414. [PMID: 35759438 DOI: 10.1152/ajpcell.00114.2022] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
Local acidification is a common feature of many disease processes such as inflammation, infarction, or solid tumor growth. Acidic pH is not merely a sequelae of disease but contributes to recruitment and regulation of immune cells, modifies metabolism of parenchymal, immune and tumor cells, modulates fibrosis, vascular permeability, oxygen availability and consumption, invasiveness of tumor cells, and impacts on cell survival. Thus, multiple pH-sensing mechanisms must exist in cells involved in these processes. These pH-sensors play important roles in normal physiology and pathophysiology, and hence might be attractive targets for pharmacological interventions. Among the pH-sensing mechanisms, OGR1 (GPR68), GPR4 (GPR4), and TDAG8 (GPR65) have emerged as important molecules. These G protein-coupled receptors are widely expressed, are upregulated in inflammation and tumors, sense changes in extracellular pH in the range between pH 8 and 6, and are involved in modulating key processes in inflammation, tumor biology, and fibrosis. This review discusses key features of these receptors and highlights important disease states and pathways affected by their activity.
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Affiliation(s)
- Pedro H Imenez Silva
- Institute of Physiology, University of Zurich, Zurich, Switzerland.,National Center of Competence in Research NCCR Kidney.CH, Switzerland
| | - Niels Olsen Câmara
- Department of Immunology, Institute of Biomedical Sciences, University of Sao Paulo, Sao Paulo, Brazil
| | - Carsten A Wagner
- Institute of Physiology, University of Zurich, Zurich, Switzerland.,National Center of Competence in Research NCCR Kidney.CH, Switzerland
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8
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When inflammation turns sour on T cells. Nat Immunol 2022; 23:991-993. [PMID: 35697839 DOI: 10.1038/s41590-022-01241-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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9
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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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10
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Alkali therapy protects renal function, suppresses inflammation, and improves cellular metabolism in kidney disease. Clin Sci (Lond) 2022; 136:557-577. [PMID: 35389462 DOI: 10.1042/cs20220095] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2022] [Revised: 03/24/2022] [Accepted: 04/07/2022] [Indexed: 11/17/2022]
Abstract
Chronic kidney disease (CKD) affects about 10-13 % of the population worldwide and halting its progression is a major clinical challenge. Metabolic acidosis is both a consequence and a possible driver of CKD progression. Alkali therapy counteracts these effects in CKD patients, but underlying mechanisms remain incompletely understood. Here we show that bicarbonate supplementation protected renal function in a murine CKD model induced by an oxalate-rich diet. Alkali therapy had no effect on the aldosterone-endothelin axis but promoted levels of the anti-aging protein klotho; moreover, it suppressed adhesion molecules required for immune cell invasion along with reducing T helper cell and inflammatory monocyte invasion. Comparing transcriptomes from the murine crystallopathy model and from human biopsies of kidney transplant recipients suffering from acidosis with or without alkali therapy unveils parallel transcriptome responses mainly associated with lipid metabolism and oxidoreductase activity. Our data reveal novel pathways associated with acidosis in kidney disease and sensitive to alkali therapy and identifies potential targets through which alkali therapy may act on CKD and that may be amenable for more targeted therapies.
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11
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Imenez Silva PH, Wagner CA. Physiological relevance of proton-activated GPCRs. Pflugers Arch 2022; 474:487-504. [PMID: 35247105 PMCID: PMC8993716 DOI: 10.1007/s00424-022-02671-1] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2021] [Revised: 02/07/2022] [Accepted: 02/08/2022] [Indexed: 12/12/2022]
Abstract
The detection of H+ concentration variations in the extracellular milieu is accomplished by a series of specialized and non-specialized pH-sensing mechanisms. The proton-activated G protein–coupled receptors (GPCRs) GPR4 (Gpr4), TDAG8 (Gpr65), and OGR1 (Gpr68) form a subfamily of proteins capable of triggering intracellular signaling in response to alterations in extracellular pH around physiological values, i.e., in the range between pH 7.5 and 6.5. Expression of these receptors is widespread for GPR4 and OGR1 with particularly high levels in endothelial cells and vascular smooth muscle cells, respectively, while expression of TDAG8 appears to be more restricted to the immune compartment. These receptors have been linked to several well-studied pH-dependent physiological activities including central control of respiration, renal adaption to changes in acid–base status, secretion of insulin and peripheral responsiveness to insulin, mechanosensation, and cellular chemotaxis. Their role in pathological processes such as the genesis and progression of several inflammatory diseases (asthma, inflammatory bowel disease), and tumor cell metabolism and invasiveness, is increasingly receiving more attention and makes these receptors novel and interesting targets for therapy. In this review, we cover the role of these receptors in physiological processes and will briefly discuss some implications for disease processes.
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Affiliation(s)
- Pedro H Imenez Silva
- Institute of Physiology, University of Zurich, Winterthurerstrasse 190, CH-8057, Zurich, Switzerland. .,National Center of Competence in Research NCCR Kidney.CH, Zurich, Switzerland.
| | - Carsten A Wagner
- Institute of Physiology, University of Zurich, Winterthurerstrasse 190, CH-8057, Zurich, Switzerland. .,National Center of Competence in Research NCCR Kidney.CH, Zurich, Switzerland.
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12
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Elemam NM, Youness RA, Hussein A, Shihab I, Yakout NM, Elwany YN, Manie TM, Talaat IM, Maghazachi AA. Expression of GPR68, an Acid-Sensing Orphan G Protein-Coupled Receptor, in Breast Cancer. Front Oncol 2022; 12:847543. [PMID: 35311103 PMCID: PMC8930915 DOI: 10.3389/fonc.2022.847543] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2022] [Accepted: 02/15/2022] [Indexed: 11/20/2022] Open
Abstract
Breast cancer (BC) is the most diagnosed cancer and the leading cause of global cancer incidence in 2020. It is quite known that highly invasive cancers have disrupted metabolism that leads to the creation of an acidic tumor microenvironment. Among the proton-sensing G protein-coupled receptors is GPR68. In this study, we aimed to explore the expression pattern of GPR68 in tissues from BC patients as well as different BC cell lines. Methods: In-silico tools were used to assess the expression of GPR68 in BC patients. The expression pattern was validated in fresh and paraffin-embedded sections of BC patients using qPCR and immunohistochemistry (IHC), respectively. Also, in-silico tools investigated GPR68 expression in different BC cell lines. Validation of GPR68 expression was performed using qPCR and immunofluorescence techniques in four different BC cell lines (MCF-7, MDA-MB-231, BT-549 and SkBr3). Results: GPR68 expression was found to be significantly increased in BC patients using the in-silico tools and validation using qPCR and IHC. Upon classification according to the molecular subtypes, the luminal subtype showed the highest GPR68 expression followed by triple-negative and Her2-enriched cells. However, upon validation in the recruited cohort, the triple-negative molecular subtype of BC patients showed the highest GPR68 expression. Also, in-silico and validation data revealed that the triple-negative breast cancer cell line MDA-MB-231 showed the highest expression of GPR68. Conclusion: Therefore, this study highlights the potential utilization of GPR68 as a possible diagnostic and/or prognostic marker in BC.
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Affiliation(s)
- Noha Mousaad Elemam
- Clinical Sciences Department, College of Medicine, University of Sharjah, Sharjah, United Arab Emirates
- Sharjah Institute of Medical Research, University of Sharjah, Sharjah, United Arab Emirates
| | - Rana A. Youness
- Biology and Biochemistry Department, School of Life and Medical Sciences, University of Hertfordshire Hosted by Global Academic Foundation, Cairo, Egypt
| | - Amal Hussein
- Department of Family and Community Medicine and Behavioral Sciences, College of Medicine, University of Sharjah, Sharjah, United Arab Emirates
| | - Israa Shihab
- Clinical Sciences Department, College of Medicine, University of Sharjah, Sharjah, United Arab Emirates
- Sharjah Institute of Medical Research, University of Sharjah, Sharjah, United Arab Emirates
| | - Nada M. Yakout
- Pathology Department, Faculty of Medicine, Alexandria University, Alexandria, Egypt
| | - Yasmine Nagy Elwany
- Clinical Oncology Department, Medical Research Institute, Alexandria University, Alexandria, Egypt
| | - Tamer M. Manie
- Department of Breast Surgery, National Cancer Institute, Cairo University, Cairo, Egypt
| | - Iman M. Talaat
- Clinical Sciences Department, College of Medicine, University of Sharjah, Sharjah, United Arab Emirates
- Sharjah Institute of Medical Research, University of Sharjah, Sharjah, United Arab Emirates
- Pathology Department, Faculty of Medicine, Alexandria University, Alexandria, Egypt
- *Correspondence: Iman M. Talaat, ; Azzam A. Maghazachi,
| | - Azzam A. Maghazachi
- Clinical Sciences Department, College of Medicine, University of Sharjah, Sharjah, United Arab Emirates
- Sharjah Institute of Medical Research, University of Sharjah, Sharjah, United Arab Emirates
- *Correspondence: Iman M. Talaat, ; Azzam A. Maghazachi,
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13
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Manosalva C, Quiroga J, Hidalgo AI, Alarcón P, Anseoleaga N, Hidalgo MA, Burgos RA. Role of Lactate in Inflammatory Processes: Friend or Foe. Front Immunol 2022; 12:808799. [PMID: 35095895 PMCID: PMC8795514 DOI: 10.3389/fimmu.2021.808799] [Citation(s) in RCA: 61] [Impact Index Per Article: 30.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2021] [Accepted: 12/23/2021] [Indexed: 12/13/2022] Open
Abstract
During an inflammatory process, shift in the cellular metabolism associated with an increase in extracellular acidification are well-known features. This pH drop in the inflamed tissue is largely attributed to the presence of lactate by an increase in glycolysis. In recent years, evidence has accumulated describing the role of lactate in inflammatory processes; however, there are differences as to whether lactate can currently be considered a pro- or anti-inflammatory mediator. Herein, we review these recent advances on the pleiotropic effects of lactate on the inflammatory process. Taken together, the evidence suggests that lactate could exert differential effects depending on the metabolic status, cell type in which the effects of lactate are studied, and the pathological process analyzed. Additionally, various targets, including post-translational modifications, G-protein coupled receptor and transcription factor activation such as NF-κB and HIF-1, allow lactate to modulate signaling pathways that control the expression of cytokines, chemokines, adhesion molecules, and several enzymes associated with immune response and metabolism. Altogether, this would explain its varied effects on inflammatory processes beyond its well-known role as a waste product of metabolism.
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Affiliation(s)
- Carolina Manosalva
- Faculty of Sciences, Institute of Pharmacy, Universidad Austral de Chile, Valdivia, Chile
| | - John Quiroga
- Laboratory of Immunometabolism, Faculty of Veterinary Sciences, Institute of Pharmacology and Morphophysiology, Universidad Austral de Chile, Valdivia, Chile.,Graduate School, Faculty of Veterinary Sciences, Universidad Austral de Chile, Valdivia, Chile
| | - Alejandra I Hidalgo
- Laboratory of Immunometabolism, Faculty of Veterinary Sciences, Institute of Pharmacology and Morphophysiology, Universidad Austral de Chile, Valdivia, Chile
| | - Pablo Alarcón
- Laboratory of Immunometabolism, Faculty of Veterinary Sciences, Institute of Pharmacology and Morphophysiology, Universidad Austral de Chile, Valdivia, Chile
| | - Nicolás Anseoleaga
- Laboratory of Immunometabolism, Faculty of Veterinary Sciences, Institute of Pharmacology and Morphophysiology, Universidad Austral de Chile, Valdivia, Chile.,Graduate School, Faculty of Veterinary Sciences, Universidad Austral de Chile, Valdivia, Chile
| | - María Angélica Hidalgo
- Laboratory of Immunometabolism, Faculty of Veterinary Sciences, Institute of Pharmacology and Morphophysiology, Universidad Austral de Chile, Valdivia, Chile
| | - Rafael Agustín Burgos
- Laboratory of Immunometabolism, Faculty of Veterinary Sciences, Institute of Pharmacology and Morphophysiology, Universidad Austral de Chile, Valdivia, Chile
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14
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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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15
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Feng Z, Liu Z, Peng K, Wu W. A Prognostic Model Based on Nine DNA Methylation-Driven Genes Predicts Overall Survival for Colorectal Cancer. Front Genet 2022; 12:779383. [PMID: 35126454 PMCID: PMC8814658 DOI: 10.3389/fgene.2021.779383] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2021] [Accepted: 11/12/2021] [Indexed: 01/07/2023] Open
Abstract
Background: Colorectal cancer (CRC) is the third most frequently diagnosed malignancy and the fourth leading cause of cancer-related death among common tumors in the world. We aimed to establish and validate a risk assessment model to predict overall survival (OS) for the CRC patients. Methods: DNA methylation-driven genes were identified by integrating DNA methylation profile and transcriptome data from The Cancer Genome Atlas (TCGA) CRC cohort. Then, a risk score model was built based on LASSO, univariable Cox and multivariable Cox regression analysis. After analyzing the clinicopathological factors, a nomogram was constructed and assessed. Another cohort from GEO was used for external validation. Afterward, the molecular and immune characteristics in the two risk score groups were analyzed. Results: In total, 705 methylation-driven genes were identified. Based on the LASSO and Cox regression analyses, nine genes, i.e., LINC01555, GSTM1, HSPA1A, VWDE, MAGEA12, ARHGAP, PTPRD, ABHD12B and TMEM88, were selected for the development of a risk score model. The Kaplan–Meier curve indicated that patients in the low-risk group had considerably better OS (P = 2e-08). The verification performed in subgroups demonstrated the validity of the model. Then, we established an OS-associated nomogram that included the risk score and significant clinicopathological factors. The concordance index of the nomogram was 0.81. A comprehensive molecular and immune characteristics analysis showed that the high-risk group was associated with tumor invasion, infiltration of immune cells executing pro-tumor suppression (such as myeloid-derived suppressor cells, regulatory T cells, immature dendritic cells) and higher expression of common inhibitory checkpoint molecules (ICPs). Conclusion: Our nine-gene associated risk assessment model is a promising signature to distinguish the prognosis for CRC patients. It is expected to serve as a predictive tool with high sensitivity and specificity for individualized prediction of OS in the patients with CRC.
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Affiliation(s)
| | | | | | - Wei Wu
- *Correspondence: Kangsheng Peng, ; Wei Wu,
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16
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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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17
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Lasola JJM, Cottingham AL, Scotland BL, Truong N, Hong CC, Shapiro P, Pearson RM. Immunomodulatory Nanoparticles Mitigate Macrophage Inflammation via Inhibition of PAMP Interactions and Lactate-Mediated Functional Reprogramming of NF-κB and p38 MAPK. Pharmaceutics 2021; 13:1841. [PMID: 34834256 PMCID: PMC8618039 DOI: 10.3390/pharmaceutics13111841] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2021] [Revised: 10/23/2021] [Accepted: 10/28/2021] [Indexed: 12/29/2022] Open
Abstract
Inflammation is a key homeostatic process involved in the body's response to a multitude of disease states including infection, autoimmune disorders, cancer, and other chronic conditions. When the initiating event is poorly controlled, severe inflammation and globally dysregulated immune responses can occur. To address the lack of therapies that efficaciously address the multiple aspects of the dysregulated immune response, we developed cargo-less immunomodulatory nanoparticles (iNPs) comprised of poly(lactic acid) (PLA) with either poly(vinyl alcohol) (PVA) or poly(ethylene-alt-maleic acid) (PEMA) as stabilizing surfactants and investigated the mechanisms by which they exert their inherent anti-inflammatory effects. We identified that iNPs leverage a multimodal mechanism of action by physically interfering with the interactions between pathogen-associated molecular patterns (PAMPs) and bone marrow-derived macrophages (BMMΦs). Additionally, we showed that iNPs mitigate proinflammatory cytokine secretions induced by LPS via a time- and composition-dependent abrogation of NF-κB p65 and p38 MAPK activation. Lastly, inhibition studies were performed to establish the role of a pH-sensing G-protein-coupled receptor, GPR68, on contributing to the activity of iNPs. These data provide evidence for the multimodal mechanism of action of iNPs and establish their potential use as a novel therapeutic for the treatment of severe inflammation.
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Affiliation(s)
- Jackline Joy Martín Lasola
- Department of Microbiology and Immunology, University of Maryland School of Medicine, 685 W. Baltimore Street, Baltimore, MD 21201, USA;
| | - Andrea L. Cottingham
- Department of Pharmaceutical Sciences, University of Maryland School of Pharmacy, 20 N. Pine Street, Baltimore, MD 21201, USA; (A.L.C.); (B.L.S.); (N.T.); (P.S.)
| | - Brianna L. Scotland
- Department of Pharmaceutical Sciences, University of Maryland School of Pharmacy, 20 N. Pine Street, Baltimore, MD 21201, USA; (A.L.C.); (B.L.S.); (N.T.); (P.S.)
| | - Nhu Truong
- Department of Pharmaceutical Sciences, University of Maryland School of Pharmacy, 20 N. Pine Street, Baltimore, MD 21201, USA; (A.L.C.); (B.L.S.); (N.T.); (P.S.)
| | - Charles C. Hong
- Division of Cardiovascular Medicine, Department of Medicine, University of Maryland School of Medicine, 110 S. Paca Street, Baltimore, MD 21201, USA;
| | - Paul Shapiro
- Department of Pharmaceutical Sciences, University of Maryland School of Pharmacy, 20 N. Pine Street, Baltimore, MD 21201, USA; (A.L.C.); (B.L.S.); (N.T.); (P.S.)
- Marlene and Stewart Greenebaum Comprehensive Cancer Center, University of Maryland School of Medicine, 22 S. Greene Street, Baltimore, MD 21201, USA
| | - Ryan M. Pearson
- Department of Pharmaceutical Sciences, University of Maryland School of Pharmacy, 20 N. Pine Street, Baltimore, MD 21201, USA; (A.L.C.); (B.L.S.); (N.T.); (P.S.)
- Marlene and Stewart Greenebaum Comprehensive Cancer Center, University of Maryland School of Medicine, 22 S. Greene Street, Baltimore, MD 21201, USA
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18
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Cicconetti F, Sestili P, Madiai V, Albertini MC, Campanella L, Coppari S, Fraternale D, Saunders B, Teodori L. Extracellular pH, osmolarity, temperature and humidity could discourage SARS-CoV-2 cell docking and propagation via intercellular signaling pathways. PeerJ 2021; 9:e12227. [PMID: 34721966 PMCID: PMC8515994 DOI: 10.7717/peerj.12227] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2021] [Accepted: 09/08/2021] [Indexed: 12/15/2022] Open
Abstract
The COVID-19 pandemic and its virus variants continue to pose a serious and long-lasting threat worldwide. To combat the pandemic, the world's largest COVID-19 vaccination campaign is currently ongoing. As of July 19th 2021, 26.2% of the world population has received at least one dose of a COVID-19 vaccine (1.04 billion), and one billion has been fully vaccinated, with very high vaccination rates in countries like Israel, Malta, and the UEA. Conversely, only 1% of people in low-income countries have received at least one dose with examples of vaccination frequency as low as 0.07% in the Democratic Republic of Congo. It is thus of paramount importance that more research on alternate methods to counter cell infection and propagation is undertaken that could be implemented in low-income countries. Moreover, an adjunctive therapeutic intervention would help to avoid disease exacerbation in high-rate vaccinated countries too. Based on experimental biochemical evidence on viral cell fusion and propagation, herein we identify (i) extracellular pH (epH), (ii) temperature, and (iii) humidity and osmolarity as critical factors. These factors are here in discussed along with their implications on mucus thick layer, proteases, abundance of sialic acid, vascular permeability and exudate/edema. Heated, humidified air containing sodium bicarbonate has long been used in the treatment of certain diseases, and here we argue that warm inhalation of sodium bicarbonate might successfully target these endpoints. Although we highlight the molecular/cellular basis and the signalling pathways to support this intervention, we underscore the need for clinical investigations to encourage further research and clinical trials. In addition, we think that such an approach is also important in light of the high mutation rate of this virus originating from a rapid increase.
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Affiliation(s)
- Franco Cicconetti
- Department of Emergency DEA-Surgery, University of Roma “La Sapienza”, Rome, Italy
| | - Piero Sestili
- Department of Biomolecular Sciences, University of Urbino, Urbino, Italy
| | - Valeria Madiai
- Laboratory of Diagnostics and Metrology, FSN-TECFIS-DIM, ENEA, Frascati-Rome, Italy
| | | | - Luigi Campanella
- Department of Chemistry, University of Roma “La Sapienza”, Rome, Italy
| | - Sofia Coppari
- Department of Biomolecular Sciences, University of Urbino, Urbino, Italy
| | - Daniele Fraternale
- Department of Biomolecular Sciences, University of Urbino, Urbino, Italy
| | - Bryan Saunders
- Applied Physiology and Nutrition Research Group, Universidade de São Paulo, São Paulo, Brazil
- Institute of Orthopaedics and Traumatology, Faculty of Medicine FMUSP, Universidade de São Paulo, São Paulo, Brazil
| | - Laura Teodori
- Laboratory of Diagnostics and Metrology, FSN-TECFIS-DIM, ENEA, Frascati-Rome, Italy
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19
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Ding Z, Dou X, Wang C, Feng G, Xie J, Zhang X. Ratiometric pH sensing by fluorescence resonance energy transfer-based hybrid semiconducting polymer dots in living cells. NANOTECHNOLOGY 2021; 32:245502. [PMID: 33636714 DOI: 10.1088/1361-6528/abea38] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/18/2021] [Accepted: 02/26/2021] [Indexed: 05/20/2023]
Abstract
Intracellular pH plays a significant role in all cell activities. Due to their precise imaging capabilities, fluorescent probes have attracted much attention for the investigation of pH-regulated processes. Detecting intracellular pH values with high throughput is critical for cell research and applications. In this work, hybrid semiconducting polymer dots (Pdots) were developed and characterized and were applied for cell imaging and exclusive ratiometric sensing of intracellular pH values. The reported Pdots were prepared by blending a synthesized block polymer (POMF) and a semiconducting polymer poly[2-methoxy-5-(2-ethylhexyloxy)-1,4-phenylenevinylene] (MEHPPV) to construct a fluorescence resonance energy transfer system for ratiometric sensing. Pdots showed many advantages, including high brightness, excellent photostability and biocompatibility, giving the pH probe high sensitivity and good stability. Our results proved the capability of POMF-MEHPPV Pdots for the detection of pH in living cells.
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Affiliation(s)
- Zhaoyang Ding
- College of Food Science and Technology, Shanghai Ocean University, Shanghai 201306, People's Republic of China
- Cancer Centre and Centre of Reproduction, Development and Aging, Faculty of Health Sciences, University of Macau, Taipa, Macau SAR 999078, People's Republic of China
| | - Xilin Dou
- College of Food Science and Technology, Shanghai Ocean University, Shanghai 201306, People's Republic of China
| | - Chunfei Wang
- Cancer Centre and Centre of Reproduction, Development and Aging, Faculty of Health Sciences, University of Macau, Taipa, Macau SAR 999078, People's Republic of China
| | - Gang Feng
- Cancer Centre and Centre of Reproduction, Development and Aging, Faculty of Health Sciences, University of Macau, Taipa, Macau SAR 999078, People's Republic of China
- Guangdong Key Laboratory for Biomedical Measurements and Ultrasound Imaging, School of Biomedical Engineering, Shenzhen University Health Science Center, Shenzhen 518060, People's Republic of China
| | - Jing Xie
- College of Food Science and Technology, Shanghai Ocean University, Shanghai 201306, People's Republic of China
| | - Xuanjun Zhang
- Cancer Centre and Centre of Reproduction, Development and Aging, Faculty of Health Sciences, University of Macau, Taipa, Macau SAR 999078, People's Republic of China
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20
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Eugene SP, Reddy VS, Trinath J. Endoplasmic Reticulum Stress and Intestinal Inflammation: A Perilous Union. Front Immunol 2020; 11:543022. [PMID: 33324392 PMCID: PMC7723926 DOI: 10.3389/fimmu.2020.543022] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2020] [Accepted: 10/28/2020] [Indexed: 12/11/2022] Open
Abstract
The intestinal tract encompasses the largest mucosal surface fortified with a fine layer of intestinal epithelial cells along with highly sophisticated network of the lamina propria immune cells that are indispensable to sustain gut homeostasis. However, it can be challenging to uphold homeostasis when these cells in the intestine are perpetually exposed to insults of both endogenous and exogenous origin. The complex networking and dynamic microenvironment in the intestine demand highly functional cells ultimately burdening the endoplasmic reticulum (ER) leading to ER stress. Unresolved ER stress is one of the primary contributors to the pathogenesis of inflammatory bowel diseases (IBD). Studies also suggest that ER stress can be the primary cause of inflammation and/or the consequence of inflammation. Therefore, understanding the patterns of expression of ER stress regulators and deciphering the intricate interplay between ER stress and inflammatory pathways in intestinal epithelial cells in association with lamina propria immune cells contribute toward the development of novel therapies to tackle IBD. This review provides imperative insights into the molecular markers involved in the pathogenesis of IBD by potentiating ER stress and inflammation and briefly describes the potential pharmacological intervention strategies to mitigate ER stress and IBD. In addition, genetic mutations in the biomarkers contributing to abnormalities in the ER stress signaling pathways further emphasizes the relevance of biomarkers in potential treatment for IBD.
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Affiliation(s)
- Sanchez Preethi Eugene
- Department of Biological Sciences, Birla Institute of Technology and Science-Pilani, Hyderabad Campus, Hyderabad, India
| | | | - Jamma Trinath
- Department of Biological Sciences, Birla Institute of Technology and Science-Pilani, Hyderabad Campus, Hyderabad, India
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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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22
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Klatt W, Wallner S, Brochhausen C, Stolwijk JA, Schreml S. Expression profiles of proton-sensing G-protein coupled receptors in common skin tumors. Sci Rep 2020; 10:15327. [PMID: 32948783 PMCID: PMC7501253 DOI: 10.1038/s41598-020-71700-9] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2020] [Accepted: 08/19/2020] [Indexed: 12/18/2022] Open
Abstract
The proton-sensing GPCRs (pH-GPCRs) GPR4 (GPR19), TDAG8 (GPR65, T-cell death associated gene 8), OGR1 (GPR68, ovarian cancer GPCR1), and G2A (GPR132, G2 accumulation protein) are involved in sensing and transducing changes in extracellular pH (pHe). Extracellular acidification is a central hallmark of solid cancer. pH-GPCR function has been associated with cancer cell proliferation, adhesion, migration and metastasis, as well as with modulation of the immune system. Little is known about the expression levels and role of pH-GPCRs in skin cancer. To better understand the functions of pH-GPCRs in skin cancer in vivo, we examined the expression-profiles of GPR4, TDAG8, OGR1 and G2A in four common skin tumors, i.e. squamous cell carcinoma (SCC), malignant melanoma (MM), compound nevus cell nevi (NCN), basal cell carcinoma (BCC). We performed immunohistochemistry and immunofluorescence staining on paraffin-embedded tissue samples acquired from patients suffering from SCC, MM, NCN or BCC. We show the expression of pH-GPCRs in four common skin cancers. Different expression patterns in the investigated skin cancer types indicate that the different pH-GPCRs may have distinct functions in tumor progression and serve as novel therapeutic targets.
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Affiliation(s)
- Wybke Klatt
- Department of Dermatology, University Medical Center Regensburg, Franz-Josef-Strauß-Allee 11, 93053, Regensburg, Germany
| | - Susanne Wallner
- Department of Dermatology, University Medical Center Regensburg, Franz-Josef-Strauß-Allee 11, 93053, Regensburg, Germany
| | - Christoph Brochhausen
- Institute of Pathology, University of Regensburg, Franz-Josef-Strauß-Allee 11, 93053, Regensburg, Germany
| | - Judith A Stolwijk
- Department of Dermatology, University Medical Center Regensburg, Franz-Josef-Strauß-Allee 11, 93053, Regensburg, Germany
- Institute of Analytical Chemistry, Chemo- and Biosensors, Faculty of Chemistry and Pharmacy, University of Regensburg, Universitätsstraße 31, 93053, Regensburg, Germany
| | - Stephan Schreml
- Department of Dermatology, University Medical Center Regensburg, Franz-Josef-Strauß-Allee 11, 93053, Regensburg, Germany.
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Zeng Z, Mukherjee A, Varghese AP, Yang XL, Chen S, Zhang H. Roles of G protein-coupled receptors in inflammatory bowel disease. World J Gastroenterol 2020; 26:1242-1261. [PMID: 32256014 PMCID: PMC7109274 DOI: 10.3748/wjg.v26.i12.1242] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/17/2019] [Revised: 01/18/2020] [Accepted: 03/05/2020] [Indexed: 02/06/2023] Open
Abstract
Inflammatory bowel disease (IBD) is a complex disease with multiple pathogenic factors. Although the pathogenesis of IBD is still unclear, a current hypothesis suggests that genetic susceptibility, environmental factors, a dysfunctional immune system, the microbiome, and the interactions of these factors substantially contribute to the occurrence and development of IBD. Although existing and emerging drugs have been proven to be effective in treating IBD, none can cure IBD permanently. G protein-coupled receptors (GPCRs) are critical signaling molecules implicated in the immune response, cell proliferation, inflammation regulation and intestinal barrier maintenance. Breakthroughs in the understanding of the structures and functions of GPCRs have provided a driving force for exploring the roles of GPCRs in the pathogenesis of diseases, thereby leading to the development of GPCR-targeted medication. To date, a number of GPCRs have been shown to be associated with IBD, significantly advancing the drug discovery process for IBD. The associations between GPCRs and disease activity, disease severity, and disease phenotypes have also paved new avenues for the precise management of patients with IBD. In this review, we mainly focus on the roles of the most studied proton-sensing GPCRs, cannabinoid receptors, and estrogen-related GPCRs in the pathogenesis of IBD and their potential clinical values in IBD and some other diseases.
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Affiliation(s)
- Zhen Zeng
- Department of Gastroenterology, Centre for Inflammatory Bowel Disease, West China Hospital, Sichuan University, Chengdu 410061, Sichuan Province, China
| | - Arjudeb Mukherjee
- West China School of Medicine, Sichuan University, Chengdu 410061, Sichuan Province, China
| | | | - Xiao-Li Yang
- Department of Gastroenterology, Centre for Inflammatory Bowel Disease, West China Hospital, Sichuan University, Chengdu 410061, Sichuan Province, China
| | - Sha Chen
- Department of Gastroenterology, Centre for Inflammatory Bowel Disease, West China Hospital, Sichuan University, Chengdu 410061, Sichuan Province, China
| | - Hu Zhang
- Department of Gastroenterology, Centre for Inflammatory Bowel Disease, West China Hospital, Sichuan University, Chengdu 410061, Sichuan Province, China
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Zhang W, Han Y, Li W, Cao L, Yan L, Qin C, Gao R. Clinical data analysis reveals the role of OGR1 (GPR68) in head and neck squamous cancer. Animal Model Exp Med 2020; 3:55-61. [PMID: 32318660 PMCID: PMC7167242 DOI: 10.1002/ame2.12105] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2019] [Revised: 01/13/2020] [Accepted: 03/02/2020] [Indexed: 12/11/2022] Open
Abstract
BACKGROUND Head and neck squamous cancer (HNSC) frequently occurs in the clinic. Revealing the role of the genes that correlate with cancer cell outgrowth will contribute to potential treatment target identification and tumor inhibition. METHODS The gene expression profiles and gene ontology of the proton-sensing G-protein-coupled receptor OGR1 were analyzed using the TCGA (The Cancer Genome Atlas) database. The effects of sex, age, race, and degree of malignancy on HNSC were investigated, and the survival times of HNSC patients with high or low/medium expression levels of OGR1 were compared. Methylation of the OGR1 promoter CpG sites was also investigated and OGR1-related genes were analyzed using gene set enrichment analysis. RESULTS OGR1 is overexpressed in HNSC patients. However, compared with the low/median expression group, the high OGR1 expression group did not have different survival rates. The OGR1 expression level differed across sex, age, race, and degree of malignancy, while the methylation of the OGR1 promoter CpG sites was maintained at a similar level. Gene set enrichment analysis revealed that OGR1 was positively correlated with head and neck cancer, cisplatin resistance, hypoxia, angiogenesis, cell migration, and TGF-β. CONCLUSION The expression of OGR1 correlated with HNSC progression and survival and thus can serve as a potential treatment target and prognostic marker.
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Affiliation(s)
- Wenlong Zhang
- Key Laboratory of Human Disease Comparative Medicine (National Health and Family Planning Commission)The Institute of Laboratory Animal ScienceChinese Academy of Medical Sciences & Peking Union Medical CollegeBeijingP.R. China
- Beijing Engineering Research Center for Experimental Animal Models of Human Critical DiseasesBeijingP.R. China
| | - Yong Han
- Department of PathologyZhejiang Provincial People’s HospitalHangzhouZhejiangP.R. China
- People’s Hospital of Hangzhou Medical CollegeHangzhouZhejiangP.R. China
- Key Laboratory of Tumor Molecular Diagnosis and Individualized Medicine of Zhejiang ProvinceHangzhouZhejiangP.R. China
| | - Weisha Li
- Key Laboratory of Human Disease Comparative Medicine (National Health and Family Planning Commission)The Institute of Laboratory Animal ScienceChinese Academy of Medical Sciences & Peking Union Medical CollegeBeijingP.R. China
- Beijing Engineering Research Center for Experimental Animal Models of Human Critical DiseasesBeijingP.R. China
| | - Lin Cao
- Key Laboratory of Human Disease Comparative Medicine (National Health and Family Planning Commission)The Institute of Laboratory Animal ScienceChinese Academy of Medical Sciences & Peking Union Medical CollegeBeijingP.R. China
- Beijing Engineering Research Center for Experimental Animal Models of Human Critical DiseasesBeijingP.R. China
| | - Libo Yan
- Key Laboratory of Human Disease Comparative Medicine (National Health and Family Planning Commission)The Institute of Laboratory Animal ScienceChinese Academy of Medical Sciences & Peking Union Medical CollegeBeijingP.R. China
- Beijing Engineering Research Center for Experimental Animal Models of Human Critical DiseasesBeijingP.R. China
| | - Chuan Qin
- Key Laboratory of Human Disease Comparative Medicine (National Health and Family Planning Commission)The Institute of Laboratory Animal ScienceChinese Academy of Medical Sciences & Peking Union Medical CollegeBeijingP.R. China
- Beijing Engineering Research Center for Experimental Animal Models of Human Critical DiseasesBeijingP.R. China
| | - Ran Gao
- Key Laboratory of Human Disease Comparative Medicine (National Health and Family Planning Commission)The Institute of Laboratory Animal ScienceChinese Academy of Medical Sciences & Peking Union Medical CollegeBeijingP.R. China
- Beijing Engineering Research Center for Experimental Animal Models of Human Critical DiseasesBeijingP.R. China
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25
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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: 33] [Impact Index Per Article: 8.3] [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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26
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Pattison LA, Callejo G, St John Smith E. Evolution of acid nociception: ion channels and receptors for detecting acid. Philos Trans R Soc Lond B Biol Sci 2019; 374:20190291. [PMID: 31544616 PMCID: PMC6790391 DOI: 10.1098/rstb.2019.0291] [Citation(s) in RCA: 38] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/27/2019] [Indexed: 12/13/2022] Open
Abstract
Nociceptors, i.e. sensory neurons tuned to detect noxious stimuli, are found in numerous phyla of the Animalia kingdom and are often polymodal, responding to a variety of stimuli, e.g. heat, cold, pressure and chemicals, such as acid. Owing to the ability of protons to have a profound effect on ionic homeostasis and damage macromolecular structures, it is no wonder that the ability to detect acid is conserved across many species. To detect changes in pH, nociceptors are equipped with an assortment of different acid sensors, some of which can detect mild changes in pH, such as the acid-sensing ion channels, proton-sensing G protein-coupled receptors and several two-pore potassium channels, whereas others, such as the transient receptor potential vanilloid 1 ion channel, require larger shifts in pH. This review will discuss the evolution of acid sensation and the different mechanisms by which nociceptors can detect acid. This article is part of the Theo Murphy meeting issue 'Evolution of mechanisms and behaviour important for pain'.
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Affiliation(s)
| | | | - Ewan St John Smith
- Department of Pharmacology, University of Cambridge, Tennis Court Road, Cambridge CB2 1PD, UK
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27
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Comprehensive Assessment of GPR68 Expression in Normal and Neoplastic Human Tissues Using a Novel Rabbit Monoclonal Antibody. Int J Mol Sci 2019; 20:ijms20215261. [PMID: 31652823 PMCID: PMC6862545 DOI: 10.3390/ijms20215261] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2019] [Revised: 10/17/2019] [Accepted: 10/22/2019] [Indexed: 02/07/2023] Open
Abstract
GPR68 (OGR1) belongs to the proton-sensing G protein-coupled receptors that are involved in cellular adaptations to pH changes during tumour development. Although expression of GPR68 has been described in many tumour cell lines, little is known about its presence in human tumour entities. We characterised the novel rabbit monoclonal anti-human GPR68 antibody 16H23L16 using various cell lines and tissue specimens. The antibody was then applied to a large series of formalin-fixed, paraffin-embedded normal and neoplastic human tissue samples. Antibody specificity was demonstrated in a Western blot analysis of GPR68-expressing cells using specific siRNAs. Immunocytochemical experiments revealed pH-dependent changes in subcellular localisation of the receptor and internalisation after stimulation with lorazepam. In normal tissue, GPR68 was present in glucagon-producing islet cells, neuroendocrine cells of the intestinal tract, gastric glands, granulocytes, macrophages, muscle layers of arteries and arterioles, and capillaries. GPR68 was also expressed in neuroendocrine tumours, where it may be a positive prognostic factor, in pheochromocytomas, cervical adenocarcinomas, and endometrial cancer, as well as in paragangliomas, medullary thyroid carcinomas, gastrointestinal stromal tumours, and pancreatic adenocarcinomas. Often, tumour capillaries were also strongly GPR68-positive. The novel antibody 16H23L16 will be a valuable tool for basic research and for identifying GPR68-expressing tumours during histopathological examinations.
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28
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Yu X, Huang XP, Kenakin TP, Slocum ST, Chen X, Martini ML, Liu J, Jin J. Design, Synthesis, and Characterization of Ogerin-Based Positive Allosteric Modulators for G Protein-Coupled Receptor 68 (GPR68). J Med Chem 2019; 62:7557-7574. [PMID: 31298539 DOI: 10.1021/acs.jmedchem.9b00869] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
G protein-coupled receptor 68 (GPR68) is an understudied orphan G protein-coupled receptor (GPCR). It is expressed most abundantly in the brain, potentially playing important roles in learning and memory. Pharmacological studies with GPR68 have been hindered by lack of chemical tools that can selectively modulate its activity. We previously reported the first small-molecule positive allosteric modulator (PAM), ogerin (1), and showed that 1 can potentiate proton activity at the GPR68-Gs pathway. Here, we report the first comprehensive structure-activity relationship (SAR) study on the scaffold of 1. Our lead compound resulted from this study, MS48107 (71), displayed 33-fold increased allosteric activity compared to 1. Compound 71 demonstrated high selectivity over closely related proton GPCRs and 48 common drug targets, and was bioavailable and brain-penetrant in mice. Thus, our SAR study has resulted in an improved GPR68 PAM for investigating the physiological and pathophysiological roles of GPR68 in vitro and in vivo.
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Affiliation(s)
- Xufen Yu
- Mount Sinai Center for Therapeutics Discovery, Departments of Pharmacological Sciences and Oncological Sciences, Tisch Cancer Institute , Icahn School of Medicine at Mount Sinai , New York , New York 10029 , United States
| | | | | | | | - Xin Chen
- Mount Sinai Center for Therapeutics Discovery, Departments of Pharmacological Sciences and Oncological Sciences, Tisch Cancer Institute , Icahn School of Medicine at Mount Sinai , New York , New York 10029 , United States
| | - Michael L Martini
- Mount Sinai Center for Therapeutics Discovery, Departments of Pharmacological Sciences and Oncological Sciences, Tisch Cancer Institute , Icahn School of Medicine at Mount Sinai , New York , New York 10029 , United States
| | - Jing Liu
- Mount Sinai Center for Therapeutics Discovery, Departments of Pharmacological Sciences and Oncological Sciences, Tisch Cancer Institute , Icahn School of Medicine at Mount Sinai , New York , New York 10029 , United States
| | - Jian Jin
- Mount Sinai Center for Therapeutics Discovery, Departments of Pharmacological Sciences and Oncological Sciences, Tisch Cancer Institute , Icahn School of Medicine at Mount Sinai , New York , New York 10029 , United States
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29
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Pharmacological inhibition of GPR4 remediates intestinal inflammation in a mouse colitis model. Eur J Pharmacol 2019; 852:218-230. [PMID: 30930250 DOI: 10.1016/j.ejphar.2019.03.038] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2018] [Revised: 03/18/2019] [Accepted: 03/22/2019] [Indexed: 12/31/2022]
Abstract
Inflammatory bowel disease (IBD) is characterized by chronic, recurring inflammation of the digestive tract. Current therapeutic approaches are limited and include biologics and steroids such as anti-TNFα monoclonal antibodies and corticosteroids, respectively. Significant adverse drug effects can occur for chronic usage and include increased risk of infection in some patients. GPR4, a pH-sensing G protein-coupled receptor, has recently emerged as a potential therapeutic target for intestinal inflammation. We have assessed the effects of a GPR4 antagonist, 2-(4-((2-Ethyl-5,7-dimethylpyrazolo[1,5-a]pyrimidin-3-yl)methyl)phenyl)-5-(piperidin-4-yl)-1,3,4-oxadiazole (GPR4 antagonist 13, also known as NE-52-QQ57) in the dextran sulfate sodium (DSS)-induced acute colitis mouse model. The GPR4 antagonist 13 inhibited intestinal inflammation. The clinical parameters such as body weight loss and fecal score were reduced in the GPR4 antagonist 13 treatment group compared to vehicle control. Macroscopic disease indicators such as colon shortening, splenic expansion, and mesenteric lymph node enlargement were all reduced in severity in the GPR4 antagonist 13 treated mice. Histopathological features of active colitis were alleviated in GPR4 antagonist 13 treatment groups compared to vehicle control. Finally, inflammatory gene expression in the colon tissues and vascular adhesion molecule expression in the intestinal endothelia were attenuated by GPR4 antagonist 13. Our results indicate that GPR4 antagonist 13 provides a protective effect in the DSS-induced acute colitis mouse model, and inhibition of GPR4 can be explored as a novel anti-inflammatory approach.
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30
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Nayak AP, Pera T, Deshpande DA, Michael JV, Liberato JR, Pan S, Tompkins E, Morelli HP, Yi R, Wang N, Penn RB. Regulation of ovarian cancer G protein-coupled receptor-1 expression and signaling. Am J Physiol Lung Cell Mol Physiol 2019; 316:L894-L902. [PMID: 30724097 DOI: 10.1152/ajplung.00426.2018] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Ovarian cancer G protein-coupled receptor 1 (OGR1) is a recently deorphanized G protein-coupled receptor shown to signal in response to low extracellular pH (↓pHo) or certain benzodiazepines. The pleiotropic nature of OGR1 signaling in human airway smooth muscle (HASM) cells suggests that OGR1 is a potential therapeutic target for the management of obstructive lung diseases. However, the basic pharmacological and regulatory features of OGR1 remain poorly understood. We employed model systems of heterologously expressed [human embryonic kidney 293 (HEK293) cells] or endogenous (HASM) OGR1 to assess changes in expression, subcellular localization, and signaling capabilities following acute or chronic treatment with ↓pHo or the benzodiazepines lorazepam and sulazepam. In HEK293 cells expressing OGR1, treatment with ↓pHo and/or lorazepam, but not sulazepam, caused rapid OGR1 internalization. In HASM cells, acute treatment with ↓pHo or benzodiazepines did not alter abundance of OGR1 mRNA; however, significant downregulation was observed following chronic treatment. Acute and chronic pretreatment of HASM cells with sulazepam or lorazepam resulted in receptor desensitization as demonstrated by reduced phosphorylation of vasodilator-stimulated phosphoprotein (VASP) or p42/p44 upon rechallenge. Acid (acute but not chronic) pretreatment of HASM cells induced desensitization of OGR1-mediated VASP (but not p42/p44) phosphorylation. In contrast to a recent study reporting OGR1 upregulation and sensitization in cardiac tissue subject to ischemic/acidic insult, chronic OGR1 activation in multiple model systems did not increase OGR1 expression or signaling capacity. The ability to induce OGR1 internalization and desensitization was activator dependent, reflecting the ability of different activators to induce specific receptor confirmations and engagement of specific heterotrimeric G proteins.
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Affiliation(s)
- Ajay P Nayak
- Department of Medicine, Center for Translational Medicine and Division of Pulmonary, Allergy and Critical Care Medicine; and Jane & Leonard Korman Respiratory Institute, Thomas Jefferson University, Philadelphia, Pennsylvania
| | - Tonio Pera
- Department of Medicine, Center for Translational Medicine and Division of Pulmonary, Allergy and Critical Care Medicine; and Jane & Leonard Korman Respiratory Institute, Thomas Jefferson University, Philadelphia, Pennsylvania
| | - Deepak A Deshpande
- Department of Medicine, Center for Translational Medicine and Division of Pulmonary, Allergy and Critical Care Medicine; and Jane & Leonard Korman Respiratory Institute, Thomas Jefferson University, Philadelphia, Pennsylvania
| | - James V Michael
- Department of Medicine, Center for Translational Medicine and Division of Pulmonary, Allergy and Critical Care Medicine; and Jane & Leonard Korman Respiratory Institute, Thomas Jefferson University, Philadelphia, Pennsylvania
| | - Jennifer R Liberato
- Department of Medicine, Center for Translational Medicine and Division of Pulmonary, Allergy and Critical Care Medicine; and Jane & Leonard Korman Respiratory Institute, Thomas Jefferson University, Philadelphia, Pennsylvania
| | - Shi Pan
- Department of Medicine, Center for Translational Medicine and Division of Pulmonary, Allergy and Critical Care Medicine; and Jane & Leonard Korman Respiratory Institute, Thomas Jefferson University, Philadelphia, Pennsylvania
| | - Eric Tompkins
- Department of Medicine, Center for Translational Medicine and Division of Pulmonary, Allergy and Critical Care Medicine; and Jane & Leonard Korman Respiratory Institute, Thomas Jefferson University, Philadelphia, Pennsylvania
| | - Henry P Morelli
- Department of Medicine, Center for Translational Medicine and Division of Pulmonary, Allergy and Critical Care Medicine; and Jane & Leonard Korman Respiratory Institute, Thomas Jefferson University, Philadelphia, Pennsylvania
| | - Roslyn Yi
- Department of Medicine, Center for Translational Medicine and Division of Pulmonary, Allergy and Critical Care Medicine; and Jane & Leonard Korman Respiratory Institute, Thomas Jefferson University, Philadelphia, Pennsylvania
| | - Nadan Wang
- Department of Medicine, Center for Translational Medicine and Division of Pulmonary, Allergy and Critical Care Medicine; and Jane & Leonard Korman Respiratory Institute, Thomas Jefferson University, Philadelphia, Pennsylvania
| | - Raymond B Penn
- Department of Medicine, Center for Translational Medicine and Division of Pulmonary, Allergy and Critical Care Medicine; and Jane & Leonard Korman Respiratory Institute, Thomas Jefferson University, Philadelphia, Pennsylvania
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31
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Wiley SZ, Sriram K, Salmerón C, Insel PA. GPR68: An Emerging Drug Target in Cancer. Int J Mol Sci 2019; 20:E559. [PMID: 30696114 PMCID: PMC6386835 DOI: 10.3390/ijms20030559] [Citation(s) in RCA: 52] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2019] [Revised: 01/18/2019] [Accepted: 01/24/2019] [Indexed: 12/19/2022] Open
Abstract
GPR68 (or ovarian cancer G protein-coupled receptor 1, OGR1) is a proton-sensing G-protein-coupled receptor (GPCR) that responds to extracellular acidity and regulates a variety of cellular functions. Acidosis is considered a defining hallmark of the tumor microenvironment (TME). GPR68 expression is highly upregulated in numerous types of cancer. Emerging evidence has revealed that GPR68 may play crucial roles in tumor biology, including tumorigenesis, tumor growth, and metastasis. This review summarizes current knowledge regarding GPR68-its expression, regulation, signaling pathways, physiological roles, and functions it regulates in human cancers (including prostate, colon and pancreatic cancer, melanoma, medulloblastoma, and myelodysplastic syndrome). The findings provide evidence for GPR68 as a potentially novel therapeutic target but in addition, we note challenges in developing drugs that target GPR68.
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Affiliation(s)
- Shu Z Wiley
- Department of Pharmacology, University of California, San Diego, La Jolla, CA 92093, USA.
| | - Krishna Sriram
- Department of Pharmacology, University of California, San Diego, La Jolla, CA 92093, USA.
| | - Cristina Salmerón
- Department of Pharmacology, University of California, San Diego, La Jolla, CA 92093, USA.
| | - Paul A Insel
- Department of Pharmacology, University of California, San Diego, La Jolla, CA 92093, USA.
- Department of Medicine, University of California, San Diego, La Jolla, CA 92093, USA.
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32
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McAleer JP, Fan J, Roar B, Primerano DA, Denvir J. Cytokine Regulation in Human CD4 T Cells by the Aryl Hydrocarbon Receptor and Gq-Coupled Receptors. Sci Rep 2018; 8:10954. [PMID: 30026493 PMCID: PMC6053392 DOI: 10.1038/s41598-018-29262-4] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2017] [Accepted: 07/09/2018] [Indexed: 12/11/2022] Open
Abstract
Th17 cells contribute to host defense on mucosal surfaces but also provoke autoimmune diseases when directed against self-antigens. Identifying therapeutic targets that regulate Th17 cell differentiation and/or cytokine production has considerable value. Here, we study the aryl hydrocarbon receptor (AhR)-dependent transcriptome in human CD4 T cells treated with Th17-inducing cytokines. We show that the AhR reciprocally regulates IL-17 and IL-22 production in human CD4 T cells. Global gene expression analysis revealed that AhR ligation decreased IL21 expression, correlating with delayed upregulation of RORC during culture with Th17-inducing cytokines. Several of the AhR-dependent genes have known roles in cellular assembly, organization, development, growth and proliferation. We further show that expression of GPR15, GPR55 and GPR68 positively correlates with IL-22 production in the presence of the AhR agonist FICZ. Activation of GPR68 with the lorazepam derivative ogerin resulted in suppression of IL-22 and IL-10 secretion by T cells, with no effect on IL-17. Under neutral Th0 conditions, ogerin and the Gq/11 receptor inhibitor YM254890 blunted IL-22 induction by FICZ. These data reveal the AhR-dependent transcriptome in human CD4 T cells and suggest the mechanism through which the AhR regulates T cell function may be partially dependent on Gq-coupled receptors including GPR68.
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Affiliation(s)
- Jeremy P McAleer
- Department of Pharmaceutical Science and Research, Marshall University School of Pharmacy, Huntington, WV, 25755, USA.
| | - Jun Fan
- Department of Biomedical Sciences, Joan C. Edwards School of Medicine, Marshall University, Huntington, WV, 25755, USA
| | - Bryanna Roar
- Department of Pharmaceutical Science and Research, Marshall University School of Pharmacy, Huntington, WV, 25755, USA
| | - Donald A Primerano
- Department of Biomedical Sciences, Joan C. Edwards School of Medicine, Marshall University, Huntington, WV, 25755, USA
| | - James Denvir
- Department of Biomedical Sciences, Joan C. Edwards School of Medicine, Marshall University, Huntington, WV, 25755, USA
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Casimir GJ, Lefèvre N, Corazza F, Duchateau J, Chamekh M. The Acid-Base Balance and Gender in Inflammation: A Mini-Review. Front Immunol 2018; 9:475. [PMID: 29593728 PMCID: PMC5854649 DOI: 10.3389/fimmu.2018.00475] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2017] [Accepted: 02/22/2018] [Indexed: 12/31/2022] Open
Abstract
In humans, acid–base balance is crucial to cell homeostasis. Acidosis is observed in numerous inflammatory processes, primarily acute conditions such as sepsis, trauma, or acute respiratory distress where females tend to exhibit better prognosis compared with males. The mechanisms underlying these gender-dependent differences are multiple, probably involving hormonal and genetic factors, particularly the X chromosome. Although pH influences multiple immunological functions, gender differences in acid–base balance have been poorly investigated. In this review, we provide an update on gender differences in human susceptibility to inflammatory diseases. We additionally discuss the potential impact of acid–base balance on the gender bias of the inflammatory response in view of our recent observation that girls present higher neutrophilic inflammation and lower pH with a trend toward better prognosis in severe sepsis. We also highlight the potent role played by endothelial cells in gender differences of inflammation through activation of proton-sensing G protein-coupled receptors.
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Affiliation(s)
- Georges Jacques Casimir
- Laboratoire académique de Pédiatrie, Hôpital Universitaire des Enfants Reine Fabiola, Université Libre de Bruxelles, Brussels, Belgium
| | - Nicolas Lefèvre
- Laboratoire académique de Pédiatrie, Hôpital Universitaire des Enfants Reine Fabiola, Université Libre de Bruxelles, Brussels, Belgium.,Laboratoire de Médecine translationnelle, Centre Hospitalier Universitaire Brugmann, Université Libre de Bruxelles, Brussels, Belgium
| | - Francis Corazza
- Laboratoire de Médecine translationnelle, Centre Hospitalier Universitaire Brugmann, Université Libre de Bruxelles, Brussels, Belgium
| | - Jean Duchateau
- Laboratoire académique de Pédiatrie, Hôpital Universitaire des Enfants Reine Fabiola, Université Libre de Bruxelles, Brussels, Belgium
| | - Mustapha Chamekh
- Laboratoire académique de Pédiatrie, Hôpital Universitaire des Enfants Reine Fabiola, Université Libre de Bruxelles, Brussels, Belgium
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Wiley SZ, Sriram K, Liang W, Chang SE, French R, McCann T, Sicklick J, Nishihara H, Lowy AM, Insel PA. GPR68, a proton-sensing GPCR, mediates interaction of cancer-associated fibroblasts and cancer cells. FASEB J 2018; 32:1170-1183. [PMID: 29092903 PMCID: PMC5892729 DOI: 10.1096/fj.201700834r] [Citation(s) in RCA: 69] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2017] [Accepted: 10/16/2017] [Indexed: 12/31/2022]
Abstract
The microenvironment of pancreatic ductal adenocarcinoma (PDAC) is characterized by a dense fibrotic stroma (desmoplasia) generated by pancreatic cancer-associated fibroblasts (CAFs) derived from pancreatic stellate cells (PSCs) and pancreatic fibroblasts (PFs). Using an unbiased GPCRomic array approach, we identified 82 G-protein-coupled receptors (GPCRs) commonly expressed by CAFs derived from 5 primary PDAC tumors. Compared with PSCs and PFs, CAFs have increased expression of GPR68 (a proton-sensing GPCR), with the results confirmed by immunoblotting, The Cancer Genome Atlas data, and immunohistochemistry of PDAC tumors. Co-culture of PSCs with PDAC cells, or incubation with TNF-α, induced GPR68 expression. GPR68 activation (by decreasing the extracellular pH) enhanced IL-6 expression via a cAMP/PKA/cAMP response element binding protein signaling pathway. Knockdown of GPR68 by short interfering RNA diminished low pH-induced production of IL-6 and enhancement of PDAC cell proliferation by CAF conditioned media. CAFs from other gastrointestinal cancers also express GPR68. PDAC cells thus induce expression by CAFs of GPR68, which senses the acidic microenvironment, thereby increasing production of fibrotic markers and IL-6 and promoting PDAC cell proliferation. CAF-expressed GPR68 is a mediator of low-pH-promoted regulation of the tumor microenvironments, in particular to PDAC cell-CAF interaction and may be a novel therapeutic target for pancreatic and perhaps other types of cancers.-Wiley, S. Z., Sriram, K., Liang, W., Chang, S. E., French, R., McCann, T., Sicklick, J., Nishihara, H., Lowy, A. M., Insel, P. A. GPR68, a proton-sensing GPCR, mediates interaction of cancer-associated fibroblasts and cancer cells.
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Affiliation(s)
- Shu Z. Wiley
- Department of Pharmacology, University of California, San Diego, La Jolla, California, USA
| | - Krishna Sriram
- Department of Pharmacology, University of California, San Diego, La Jolla, California, USA
| | - Wenjing Liang
- Department of Pharmacology, University of California, San Diego, La Jolla, California, USA
- The Key Laboratory of Cardiovascular Remodeling and Function Research, Qilu Hospital of Shandong University, Jinan, China
| | - Sarah E. Chang
- Department of Pharmacology, University of California, San Diego, La Jolla, California, USA
| | - Randall French
- Moores Cancer Center, University of California, San Diego, La Jolla, California, USA
| | - Thalia McCann
- Department of Pharmacology, University of California, San Diego, La Jolla, California, USA
| | - Jason Sicklick
- Moores Cancer Center, University of California, San Diego, La Jolla, California, USA
- Division of Surgical Oncology, Department of Surgery, University of California, San Diego, La Jolla, California, USA
| | - Hiroshi Nishihara
- Division of Clinical Cancer Genomics, Hokkaido Cancer Center, Shiroishi-ku, Sapporo, Japan
| | - Andrew M. Lowy
- Moores Cancer Center, University of California, San Diego, La Jolla, California, USA
- Division of Surgical Oncology, Department of Surgery, University of California, San Diego, La Jolla, California, USA
| | - Paul A. Insel
- Department of Pharmacology, University of California, San Diego, La Jolla, California, USA
- Department of Medicine, University of California, San Diego, La Jolla, USA
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35
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González-Mariscal L, Raya-Sandino A, González-González L, Hernández-Guzmán C. Relationship between G proteins coupled receptors and tight junctions. Tissue Barriers 2018; 6:e1414015. [PMID: 29420165 DOI: 10.1080/21688370.2017.1414015] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Tight junctions (TJs) are sites of cell-cell adhesion, constituted by a cytoplasmic plaque of molecules linked to integral proteins that form a network of strands around epithelial and endothelial cells at the uppermost portion of the lateral membrane. TJs maintain plasma membrane polarity and form channels and barriers that regulate the transit of ions and molecules through the paracellular pathway. This structure that regulates traffic between the external milieu and the organism is affected in numerous pathological conditions and constitutes an important target for therapeutic intervention. Here, we describe how a wide array of G protein-coupled receptors that are activated by diverse stimuli including light, ions, hormones, peptides, lipids, nucleotides and proteases, signal through heterotrimeric G proteins, arrestins and kinases to regulate TJs present in the blood-brain barrier, the blood-retinal barrier, renal tubular cells, keratinocytes, lung and colon, and the slit diaphragm of the glomerulus.
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Affiliation(s)
- Lorenza González-Mariscal
- a Department of Physiology , Biophysics and Neuroscience, Center for Research and Advanced Studies (Cinvestav) , Mexico City , Mexico
| | - Arturo Raya-Sandino
- a Department of Physiology , Biophysics and Neuroscience, Center for Research and Advanced Studies (Cinvestav) , Mexico City , Mexico
| | - Laura González-González
- a Department of Physiology , Biophysics and Neuroscience, Center for Research and Advanced Studies (Cinvestav) , Mexico City , Mexico
| | - Christian Hernández-Guzmán
- a Department of Physiology , Biophysics and Neuroscience, Center for Research and Advanced Studies (Cinvestav) , Mexico City , Mexico
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36
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Functional profiling of microtumors to identify cancer associated fibroblast-derived drug targets. Oncotarget 2017; 8:99913-99930. [PMID: 29245949 PMCID: PMC5725140 DOI: 10.18632/oncotarget.21915] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2017] [Accepted: 09/29/2017] [Indexed: 12/27/2022] Open
Abstract
Recent advances in chemotherapeutics highlight the importance of molecularly-targeted perturbagens. Although these therapies typically address dysregulated cancer cell proteins, there are increasing therapeutic modalities that take into consideration cancer cell-extrinsic factors. Targeting components of tumor stroma such as vascular or immune cells has been shown to represent an efficacious approach in cancer treatment. Cancer-associated fibroblasts (CAFs) exemplify an important stromal component that can be exploited in targeted therapeutics, though their employment in drug discovery campaigns has been relatively minimal due to technical logistics in assaying for CAF-tumor interactions. Here we report a 3-dimensional multi-culture tumor:CAF spheroid phenotypic screening platform that can be applied to high-content drug discovery initiatives. Using a functional genomics approach we systematically profiled 1,024 candidate genes for CAF-intrinsic anti-spheroid activity; identifying several CAF genes important for development and maintenance of tumor:CAF co-culture spheroids. Along with previously reported genes such as WNT, we identify CAF-derived targets such as ARAF and COL3A1 upon which the tumor compartment depends for spheroid development. Specifically, we highlight the G-protein-coupled receptor OGR1 as a unique CAF-specific protein that may represent an attractive drug target for treating colorectal cancer. In vivo, murine colon tumor implants in OGR1 knockout mice displayed delayed tumor growth compared to tumors implanted in wild type littermate controls. These findings demonstrate a robust microphysiological screening approach for identifying new CAF targets that may be applied to drug discovery efforts.
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Fagundes RR, Taylor CT. Determinants of hypoxia-inducible factor activity in the intestinal mucosa. J Appl Physiol (1985) 2017; 123:1328-1334. [PMID: 28408694 DOI: 10.1152/japplphysiol.00203.2017] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2017] [Revised: 03/28/2017] [Accepted: 04/07/2017] [Indexed: 12/16/2022] Open
Abstract
The intestinal mucosa is exposed to fluctuations in oxygen levels due to constantly changing rates of oxygen demand and supply and its juxtaposition with the anoxic environment of the intestinal lumen. This frequently results in a state of hypoxia in the healthy mucosa even in the physiologic state. Furthermore, pathophysiologic hypoxia (which is more severe and extensive) is associated with chronic inflammatory diseases including inflammatory bowel disease (IBD). The hypoxia-inducible factor (HIF), a ubiquitously expressed regulator of cellular adaptation to hypoxia, is central to both the adaptive and the inflammatory responses of cells of the intestinal mucosa in IBD patients. In this review, we discuss the microenvironmental factors which influence the level of HIF activity in healthy and inflamed intestinal mucosae and the consequences that increased HIF activity has for tissue function and disease progression.
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Affiliation(s)
- Raphael R Fagundes
- Graduate School of Medical Sciences, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands; and.,UCD Conway Institute, Systems Biology Ireland and School of Medicine, University College Dublin, Belfield, Dublin, Ireland
| | - Cormac T Taylor
- UCD Conway Institute, Systems Biology Ireland and School of Medicine, University College Dublin, Belfield, Dublin, Ireland
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38
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Guiton PS, Sagawa JM, Fritz HM, Boothroyd JC. An in vitro model of intestinal infection reveals a developmentally regulated transcriptome of Toxoplasma sporozoites and a NF-κB-like signature in infected host cells. PLoS One 2017; 12:e0173018. [PMID: 28362800 PMCID: PMC5376300 DOI: 10.1371/journal.pone.0173018] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2016] [Accepted: 02/12/2017] [Indexed: 01/13/2023] Open
Abstract
Toxoplasmosis is a zoonotic infection affecting approximately 30% of the world’s human population. After sexual reproduction in the definitive feline host, Toxoplasma oocysts, each containing 8 sporozoites, are shed into the environment where they can go on to infect humans and other warm-blooded intermediate hosts. Here, we use an in vitro model to assess host transcriptomic changes that occur in the earliest stages of such infections. We show that infection of rat intestinal epithelial cells with mature sporozoites primarily results in higher expression of genes associated with Tumor Necrosis Factor alpha (TNFα) signaling via NF-κB. Furthermore, we find that, consistent with their biology, these mature, invaded sporozoites display a transcriptome intermediate between the previously reported day 10 oocysts and that of their tachyzoite counterparts. Thus, this study uncovers novel host and pathogen factors that may be critical for the establishment of a successful intracellular niche following sporozoite-initiated infection.
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Affiliation(s)
- Pascale S. Guiton
- Department of Microbiology and Immunology, Stanford University School of Medicine, Stanford, California, United States of America
| | - Janelle M. Sagawa
- Department of Veterinary Microbiology and Pathology, Washington State University, Pullman, Washington, United States of America
| | - Heather M. Fritz
- Department of Veterinary Microbiology and Pathology, Washington State University, Pullman, Washington, United States of America
| | - John C. Boothroyd
- Department of Microbiology and Immunology, Stanford University School of Medicine, Stanford, California, United States of America
- * E-mail:
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Sanderlin EJ, Leffler NR, Lertpiriyapong K, Cai Q, Hong H, Bakthavatchalu V, Fox JG, Oswald JZ, Justus CR, Krewson EA, O'Rourke D, Yang LV. GPR4 deficiency alleviates intestinal inflammation in a mouse model of acute experimental colitis. Biochim Biophys Acta Mol Basis Dis 2016; 1863:569-584. [PMID: 27940273 DOI: 10.1016/j.bbadis.2016.12.005] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2016] [Revised: 11/13/2016] [Accepted: 12/06/2016] [Indexed: 02/07/2023]
Abstract
GPR4 is a proton-sensing G protein-coupled receptor that can be activated by extracellular acidosis. It has recently been demonstrated that activation of GPR4 by acidosis increases the expression of numerous inflammatory and stress response genes in vascular endothelial cells (ECs) and also augments EC-leukocyte adhesion. Inhibition of GPR4 by siRNA or small molecule inhibitors reduces endothelial cell inflammation. As acidotic tissue microenvironments exist in many types of inflammatory disorders, including inflammatory bowel disease (IBD), we examined the role of GPR4 in intestinal inflammation using a dextran sulfate sodium (DSS)-induced acute colitis mouse model. We observed that GPR4 mRNA expression was increased in mouse and human IBD tissues when compared to control intestinal tissues. To determine the function of GPR4 in intestinal inflammation, wild-type and GPR4-deficient mice were treated with 3% DSS for 7days to induce acute colitis. Our results showed that the severity of colitis was decreased in GPR4-deficient DSS-treated mice in comparison to wild-type DSS-treated mice. Clinical parameters, macroscopic disease indicators, and histopathological features were less severe in the DSS-treated GPR4-deficient mice than the DSS-treated wild-type mice. Endothelial adhesion molecule expression, leukocyte infiltration, and isolated lymphoid follicle (ILF) formation were reduced in intestinal tissues of DSS-treated GPR4-null mice. Collectively, our results suggest GPR4 provides a pro-inflammatory role in the inflamed gut as the absence of GPR4 ameliorates intestinal inflammation in the acute experimental colitis mouse model.
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Affiliation(s)
- Edward J Sanderlin
- Department of Internal Medicine, Brody School of Medicine, East Carolina University, USA
| | - Nancy R Leffler
- Department of Internal Medicine, Brody School of Medicine, East Carolina University, USA
| | - Kvin Lertpiriyapong
- Department of Comparative Medicine, Brody School of Medicine, East Carolina University, USA
| | - Qi Cai
- Department of Pathology, Brody School of Medicine, East Carolina University, USA
| | - Heng Hong
- Department of Pathology, Brody School of Medicine, East Carolina University, USA
| | | | - James G Fox
- Division of Comparative Medicine, Massachusetts Institute of Technology, USA
| | - Joani Zary Oswald
- Department of Anatomy and Cell Biology, Brody School of Medicine, East Carolina University, USA
| | - Calvin R Justus
- Department of Internal Medicine, Brody School of Medicine, East Carolina University, USA
| | - Elizabeth A Krewson
- Department of Anatomy and Cell Biology, Brody School of Medicine, East Carolina University, USA
| | - Dorcas O'Rourke
- Department of Comparative Medicine, Brody School of Medicine, East Carolina University, USA
| | - Li V Yang
- Department of Internal Medicine, Brody School of Medicine, East Carolina University, USA; Department of Anatomy and Cell Biology, Brody School of Medicine, East Carolina University, USA.
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40
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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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Naydenov NG, Feygin A, Wang D, Kuemmerle JF, Harris G, Conti MA, Adelstein RS, Ivanov AI. Nonmuscle Myosin IIA Regulates Intestinal Epithelial Barrier in vivo and Plays a Protective Role During Experimental Colitis. Sci Rep 2016; 6:24161. [PMID: 27063635 PMCID: PMC4827066 DOI: 10.1038/srep24161] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2015] [Accepted: 03/21/2016] [Indexed: 02/07/2023] Open
Abstract
The actin cytoskeleton is a critical regulator of intestinal mucosal barrier permeability, and the integrity of epithelial adherens junctions (AJ) and tight junctions (TJ). Non muscle myosin II (NM II) is a key cytoskeletal motor that controls actin filament architecture and dynamics. While NM II has been implicated in the regulation of epithelial junctions in vitro, little is known about its roles in the intestinal mucosa in vivo. In this study, we generated a mouse model with an intestinal epithelial-specific knockout of NM IIA heavy chain (NM IIA cKO) and examined the structure and function of normal gut barrier, and the development of experimental colitis in these animals. Unchallenged NM IIA cKO mice showed increased intestinal permeability and altered expression/localization of several AJ/TJ proteins. They did not develop spontaneous colitis, but demonstrated signs of a low-scale mucosal inflammation manifested by prolapses, lymphoid aggregates, increased cytokine expression, and neutrophil infiltration in the gut. NM IIA cKO animals were characterized by a more severe disruption of the gut barrier and exaggerated mucosal injury during experimentally-induced colitis. Our study provides the first evidence that NM IIA plays important roles in establishing normal intestinal barrier, and protection from mucosal inflammation in vivo.
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Affiliation(s)
- Nayden G Naydenov
- Department of Human and Molecular Genetics, Virginia Commonwealth University, Richmond, VA23298
| | - Alex Feygin
- Department of Human and Molecular Genetics, Virginia Commonwealth University, Richmond, VA23298
| | - Dongdong Wang
- Department of Human and Molecular Genetics, Virginia Commonwealth University, Richmond, VA23298
| | - John F Kuemmerle
- Department of Internal Medicine, Virginia Commonwealth University, Richmond, VA 23298
| | - Gianni Harris
- Department of Medicine, University of Rochester School of Medicine, Rochester, NY
| | - Mary Anne Conti
- Laboratory of Molecular Cardiology, NHLBI, National Institutes of Health, Bethesda, Maryland 20892
| | - Robert S Adelstein
- Laboratory of Molecular Cardiology, NHLBI, National Institutes of Health, Bethesda, Maryland 20892
| | - Andrei I Ivanov
- Department of Human and Molecular Genetics, Virginia Commonwealth University, Richmond, VA23298.,VCU Massey Cancer Center, Virginia Commonwealth University, Richmond, VA 23298.,Virginia Institute of Molecular Medicine, Richmond, VA 23298
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42
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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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