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Shi Z, Liu X, Wu S, Song N, Tang Q, Li H, Luo S, Chan ASC, Cai X, Liu H, Jiang X. Discovery of Novel Peptide Antagonists Targeting GPR55 for Liver Inflammation and Fibrosis. J Med Chem 2024; 67:12085-12098. [PMID: 38991128 DOI: 10.1021/acs.jmedchem.4c00834] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/13/2024]
Abstract
Liver fibrosis is a condition characterized by aberrant proliferation of connective tissue in the liver resulting from diverse etiological factors. G protein-coupled receptor GPR55 has recently been identified as a regulator of liver diseases. Herein, we report the discovery of a cyclic peptide P1-1 that antagonizes GPR55 and suppresses collagen secretion in hepatic stellate cells. The alanine scanning and docking study was carried out to predict the binding mode and allowed for further structural optimization of peptide antagonists for GPR55. The subsequent in vivo study demonstrated that P1-1 ameliorates CCl4-induce and MCD-diet-induce acute liver inflammation and fibrosis. Further study indicates that P1-1 reduces reactive oxygen species (ROS) production, attenuates ER stress, and inhibits mitochondria-associated hepatocyte apoptosis. In this work, we provided the first successful example of antagonizing GPR55 for liver inflammation and fibrosis, which validates GPR55 as a promising target for the treatment of liver fibrosis and affords a high-potent GPR55 antagonist P1-1 as a potential therapeutic candidate.
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Affiliation(s)
- Zihan Shi
- State Key Laboratory of Anti-Infective Drug Discovery and Development, School of Pharmaceutical Sciences, Sun Yat-sen University, Guangzhou 510006, China
| | - Xianyan Liu
- State Key Laboratory of Anti-Infective Drug Discovery and Development, School of Pharmaceutical Sciences, Sun Yat-sen University, Guangzhou 510006, China
| | - Shuohan Wu
- State Key Laboratory of Anti-Infective Drug Discovery and Development, School of Pharmaceutical Sciences, Sun Yat-sen University, Guangzhou 510006, China
| | - Nazi Song
- State Key Laboratory of Anti-Infective Drug Discovery and Development, School of Pharmaceutical Sciences, Sun Yat-sen University, Guangzhou 510006, China
| | - Qinglin Tang
- State Key Laboratory of Anti-Infective Drug Discovery and Development, School of Pharmaceutical Sciences, Sun Yat-sen University, Guangzhou 510006, China
- Shenzhen Turier Biotech. Co. Ltd, Shenzhen 518000, China
| | - Haonan Li
- State Key Laboratory of Anti-Infective Drug Discovery and Development, School of Pharmaceutical Sciences, Sun Yat-sen University, Guangzhou 510006, China
| | - Suijia Luo
- Shenzhen Turier Biotech. Co. Ltd, Shenzhen 518000, China
| | - Albert S C Chan
- State Key Laboratory of Anti-Infective Drug Discovery and Development, School of Pharmaceutical Sciences, Sun Yat-sen University, Guangzhou 510006, China
| | - Xiaoqing Cai
- State Key Laboratory of Anti-Infective Drug Discovery and Development, School of Pharmaceutical Sciences, Sun Yat-sen University, Guangzhou 510006, China
| | - Han Liu
- State Key Laboratory of Anti-Infective Drug Discovery and Development, School of Pharmaceutical Sciences, Sun Yat-sen University, Guangzhou 510006, China
| | - Xianxing Jiang
- State Key Laboratory of Anti-Infective Drug Discovery and Development, School of Pharmaceutical Sciences, Sun Yat-sen University, Guangzhou 510006, China
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Apweiler M, Saliba SW, Sun L, Streyczek J, Normann C, Hellwig S, Bräse S, Fiebich BL. Modulation of neuroinflammation and oxidative stress by targeting GPR55 - new approaches in the treatment of psychiatric disorders. Mol Psychiatry 2024:10.1038/s41380-024-02614-5. [PMID: 38796643 DOI: 10.1038/s41380-024-02614-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/15/2023] [Revised: 05/10/2024] [Accepted: 05/15/2024] [Indexed: 05/28/2024]
Abstract
Pharmacological treatment of psychiatric disorders remains challenging in clinical, pharmacological, and scientific practice. Even if many different substances are established for treating different psychiatric conditions, subgroups of patients show only small or no response to the treatment. The neuroinflammatory hypothesis of the genesis of psychiatric disorders might explain underlying mechanisms in these non-responders. For that reason, recent research focus on neuroinflammatory processes and oxidative stress as possible causes of psychiatric disorders. G-protein coupled receptors (GPCRs) form the biggest superfamily of membrane-bound receptors and are already well known as pharmacological targets in various diseases. The G-protein coupled receptor 55 (GPR55), a receptor considered part of the endocannabinoid system, reveals promising modulation of neuroinflammatory and oxidative processes. Different agonists and antagonists reduce pro-inflammatory cytokine release, enhance the synthesis of anti-inflammatory mediators, and protect cells from oxidative damage. For this reason, GPR55 ligands might be promising compounds in treating subgroups of patients suffering from psychiatric disorders related to neuroinflammation or oxidative stress. New approaches in drug design might lead to new compounds targeting different pathomechanisms of those disorders in just one molecule.
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Affiliation(s)
- Matthias Apweiler
- Neuroimmunology and Neurochemistry Research Group, Department of Psychiatry and Psychotherapy, Medical Center - University of Freiburg, Faculty of Medicine, University of Freiburg, D-79104, Freiburg, Germany
- Department of Cardiology and Angiology, Medical Center - University of Freiburg, Faculty of Medicine, University of Freiburg, D-79106 Freiburg, Germany
| | - Soraya Wilke Saliba
- Neuroimmunology and Neurochemistry Research Group, Department of Psychiatry and Psychotherapy, Medical Center - University of Freiburg, Faculty of Medicine, University of Freiburg, D-79104, Freiburg, Germany
| | - Lu Sun
- Neuroimmunology and Neurochemistry Research Group, Department of Psychiatry and Psychotherapy, Medical Center - University of Freiburg, Faculty of Medicine, University of Freiburg, D-79104, Freiburg, Germany
| | - Jana Streyczek
- Neuroimmunology and Neurochemistry Research Group, Department of Psychiatry and Psychotherapy, Medical Center - University of Freiburg, Faculty of Medicine, University of Freiburg, D-79104, Freiburg, Germany
| | - Claus Normann
- Department of Psychiatry and Psychotherapy, Medical Center - University of Freiburg, Faculty of Medicine, University of Freiburg, D-79104, Freiburg, Germany
| | - Sabine Hellwig
- Department of Psychiatry and Psychotherapy, Medical Center - University of Freiburg, Faculty of Medicine, University of Freiburg, D-79104, Freiburg, Germany
| | - Stefan Bräse
- Institute of Organic Chemistry, Karlsruhe Institute of Technology (KIT), Kaiserstrasse 12, D-76131, Karlsruhe, Germany
- Institute of Biological and Chemical Systems-Functional Molecular Systems (IBCS-FMS), Karlsruhe Institute of Technology (KIT), Kaiserstrasse 12, D-76131, Karlsruhe, Germany
| | - Bernd L Fiebich
- Neuroimmunology and Neurochemistry Research Group, Department of Psychiatry and Psychotherapy, Medical Center - University of Freiburg, Faculty of Medicine, University of Freiburg, D-79104, Freiburg, Germany.
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Francisco V, Ait Eldjoudi D, González-Rodríguez M, Ruiz-Fernández C, Cordero-Barreal A, Marques P, Sanz MJ, Real JT, Lago F, Pino J, Farrag Y, Gualillo O. Metabolomic signature and molecular profile of normal and degenerated human intervertebral disc cells. Spine J 2023; 23:1549-1562. [PMID: 37339697 DOI: 10.1016/j.spinee.2023.06.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/20/2022] [Revised: 05/02/2023] [Accepted: 06/03/2023] [Indexed: 06/22/2023]
Abstract
BACKGROUND CONTEXT Intervertebral disc degeneration (IVDD) is an incurable, specific treatment-orphan disease with an increasing burden worldwide. Although great efforts have been made to develop new regenerative therapies, their clinical success is limited. PURPOSE Characterize the metabolomic and gene expression changes underpinning human disc degeneration. This study also aimed to disclose new molecular targets for developing and optimizing novel biological approaches for IVDD. STUDY DESIGN Intervertebral disc cells were obtained from IVDD patients undergoing circumferential arthrodesis surgery or from healthy subjects. Mimicking the harmful microenvironment of degenerated discs, cells isolated from the nucleus pulposus (NP) and annulus fibrosus (AF) were exposed to the proinflammatory cytokine IL-1β and the adipokine leptin. The metabolomic signature and molecular profile of human disc cells were unraveled for the first time. METHODS The metabolomic and lipidomic profiles of IVDD and healthy disc cells were analyzed by high-performance liquid chromatography-mass spectrometry (UHPLC-MS). Gene expression was investigated by SYBR green-based quantitative real-time RT-PCR. Altered metabolites and gene expression were documented. RESULTS Lipidomic analysis revealed decreased levels of triacylglycerols (TG), diacylglycerol (DG), fatty acids (FA), phosphatidylcholine (PC), lysophosphatidylinositols (LPI) and sphingomyelin (SM), and increased levels of bile acids (BA) and ceramides, likely promoting disc cell metabolism changing from glycolysis to fatty acid oxidation and following cell death. The gene expression profile of disc cells suggests LCN2 and LEAP2/GHRL as promising molecular therapeutic targets for disc degeneration and demonstrates the expression of genes related to inflammation (NOS2, COX2, IL-6, IL-8, IL-1β, and TNF-α) or encoding adipokines (PGRN, NAMPT, NUCB2, SERPINE2, and RARRES2), matrix metalloproteinases (MMP9 and MMP13), and vascular adhesion molecules (VCAM1). CONCLUSIONS Altogether, the presented results disclose the NP and AF cell biology changes from healthy to degenerated discs, allowing the identification of promising molecular therapeutic targets for intervertebral disc degeneration. CLINICAL SIGNIFICANCE Our results are relevant to improving current biological-based strategies aiming to repair IVD by restoring cellular lipid metabolites as well as adipokines homeostasis. Ultimately, our results will be valuable for successful, long-lasting relief of painful IVDD.
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Affiliation(s)
- Vera Francisco
- Institute of Health Research INCLIVA and Endocrinology and Nutrition Service, University Clinic Hospital of Valencia, Calle Menéndez y Pelayo nº4, 46010 Valencia, Spain; SERGAS (Servizo Galego de Saude) and IDIS (Instituto de Investigación Sanitaria de Santiago), NEIRID Lab (Neuroendocrine Interactions in Rheumatology and Inflammatory Diseases), Research Laboratory 9, Santiago University Clinical Hospital, Tr.ª da Choupana s/n, 15706 Santiago de Compostela, Spain
| | - Djedjiga Ait Eldjoudi
- SERGAS (Servizo Galego de Saude) and IDIS (Instituto de Investigación Sanitaria de Santiago), NEIRID Lab (Neuroendocrine Interactions in Rheumatology and Inflammatory Diseases), Research Laboratory 9, Santiago University Clinical Hospital, Tr.ª da Choupana s/n, 15706 Santiago de Compostela, Spain
| | - María González-Rodríguez
- SERGAS (Servizo Galego de Saude) and IDIS (Instituto de Investigación Sanitaria de Santiago), NEIRID Lab (Neuroendocrine Interactions in Rheumatology and Inflammatory Diseases), Research Laboratory 9, Santiago University Clinical Hospital, Tr.ª da Choupana s/n, 15706 Santiago de Compostela, Spain
| | - Clara Ruiz-Fernández
- SERGAS (Servizo Galego de Saude) and IDIS (Instituto de Investigación Sanitaria de Santiago), NEIRID Lab (Neuroendocrine Interactions in Rheumatology and Inflammatory Diseases), Research Laboratory 9, Santiago University Clinical Hospital, Tr.ª da Choupana s/n, 15706 Santiago de Compostela, Spain
| | - Alfonso Cordero-Barreal
- SERGAS (Servizo Galego de Saude) and IDIS (Instituto de Investigación Sanitaria de Santiago), NEIRID Lab (Neuroendocrine Interactions in Rheumatology and Inflammatory Diseases), Research Laboratory 9, Santiago University Clinical Hospital, Tr.ª da Choupana s/n, 15706 Santiago de Compostela, Spain
| | - Patrice Marques
- University Clinic Hospital of Valencia and Department of Pharmacology, Faculty of Medicine and Odontology, Institute of Health Research INCLIVA, University of Valencia, Calle Menéndez y Pelayo, nº4, 46010 Valencia, Spain
| | - Maria Jesus Sanz
- University Clinic Hospital of Valencia and Department of Pharmacology, Faculty of Medicine and Odontology, Institute of Health Research INCLIVA, University of Valencia, Calle Menéndez y Pelayo, nº4, 46010 Valencia, Spain; CIBERDEM-Spanish Biomedical Research Centre in Diabetes and Associated Metabolic Disorders, ISCIII, Av. Monforte de Lemos, 3-5, 28029 Madrid, Spain
| | - José T Real
- Institute of Health Research INCLIVA and Endocrinology and Nutrition Service, University Clinic Hospital of Valencia, Calle Menéndez y Pelayo nº4, 46010 Valencia, Spain; CIBERDEM-Spanish Biomedical Research Centre in Diabetes and Associated Metabolic Disorders, ISCIII, Av. Monforte de Lemos, 3-5, 28029 Madrid, Spain; Department of Medicine, Faculty of Medicine and Odontology, University of Valencia, Av. de Blasco Ibáñez nº15, 46010 Valencia, Spain
| | - Francisca Lago
- SERGAS (Servizo Galego de Saude) and IDIS (Instituto de Investigación Sanitaria de Santiago), Molecular and Cellular Cardiology Lab, Research Laboratory 7, Santiago University Clinical Hospital, Tr.ª da Choupana s/n, 15706 Santiago de Compostela, Spain
| | - Jesus Pino
- SERGAS (Servizo Galego de Saude) and IDIS (Instituto de Investigación Sanitaria de Santiago), NEIRID Lab (Neuroendocrine Interactions in Rheumatology and Inflammatory Diseases), Research Laboratory 9, Santiago University Clinical Hospital, Tr.ª da Choupana s/n, 15706 Santiago de Compostela, Spain.
| | - Yousof Farrag
- SERGAS (Servizo Galego de Saude) and IDIS (Instituto de Investigación Sanitaria de Santiago), NEIRID Lab (Neuroendocrine Interactions in Rheumatology and Inflammatory Diseases), Research Laboratory 9, Santiago University Clinical Hospital, Tr.ª da Choupana s/n, 15706 Santiago de Compostela, Spain
| | - Oreste Gualillo
- SERGAS (Servizo Galego de Saude) and IDIS (Instituto de Investigación Sanitaria de Santiago), NEIRID Lab (Neuroendocrine Interactions in Rheumatology and Inflammatory Diseases), Research Laboratory 9, Santiago University Clinical Hospital, Tr.ª da Choupana s/n, 15706 Santiago de Compostela, Spain
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Kavouris JA, McCall LI, Giardini MA, De Muylder G, Thomas D, Garcia-Pérez A, Cantizani J, Cotillo I, Fiandor JM, McKerrow JH, De Oliveira CI, Siqueira-Neto JL, González S, Brown LE, Schaus SE. Discovery of pyrazolopyrrolidinones as potent, broad-spectrum inhibitors of Leishmania infection. FRONTIERS IN TROPICAL DISEASES 2023; 3:1011124. [PMID: 36818551 PMCID: PMC9937549 DOI: 10.3389/fitd.2022.1011124] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
Abstract
Introduction Leishmaniasis is a parasitic disease that affects more than 1 million people worldwide annually, predominantly in resource-limited settings. The challenge in compound development is to exhibit potent activity against the intracellular stage of the parasite (the stage present in the mammalian host) without harming the infected host cells. We have identified a compound series (pyrazolopyrrolidinones) active against the intracellular parasites of Leishmania donovani and L. major; the causative agents of visceral and cutaneous leishmaniasis in the Old World, respectively. Methods In this study, we performed medicinal chemistry on a newly discovered antileishmanial chemotype, with over 100 analogs tested. Studies included assessments of antileishmanial potency, toxicity towards host cells, and in vitro ADME screening of key drug properties. Results and discussion Members of the series showed high potency against the deadliest form, visceral leishmaniasis (approximate EC50 ≥ 0.01 μM without harming the host macrophage up to 10.0 μM). In comparison, the most efficient monotherapy treatment for visceral leishmaniasis is amphotericin B, which presents similar activity in the same assay (EC50 = 0.2 μM) while being cytotoxic to the host cell at 5.0 μM. Continued development of this compound series with the Discovery Partnership with Academia (DPAc) program at the GlaxoSmithKline Diseases of the Developing World (GSK DDW) laboratories found that the compounds passed all of GSK's criteria to be defined as a potential lead drug series for leishmaniasis. Conclusion Here, we describe preliminary structure-activity relationships for antileishmanial pyrazolopyrrolidinones, and our progress towards the identification of candidates for future in vivo assays in models of visceral and cutaneous leishmaniasis.
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Affiliation(s)
- John A. Kavouris
- Department of Chemistry and Center for Molecular Discovery (BU-CMD), Boston University, Boston, Massachusetts, United States of America
| | - Laura-Isobel McCall
- Center for Discovery and Innovation in Parasitic Diseases, Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California San Diego, La Jolla, California, United States of America
| | - Miriam A. Giardini
- Center for Discovery and Innovation in Parasitic Diseases, Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California San Diego, La Jolla, California, United States of America
| | - Geraldine De Muylder
- Department of Pathology, Sandler Center for Drug Discovery, University of California San Francisco, San Francisco, California, United States of America
| | - Diane Thomas
- Center for Discovery and Innovation in Parasitic Diseases, Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California San Diego, La Jolla, California, United States of America
| | - Adolfo Garcia-Pérez
- Global Health Medicines R&D, GlaxoSmithKline, Severo Ochoa 2, 28760 Tres Cantos, Madrid, Spain
| | - Juan Cantizani
- Global Health Medicines R&D, GlaxoSmithKline, Severo Ochoa 2, 28760 Tres Cantos, Madrid, Spain
| | - Ignacio Cotillo
- Global Health Medicines R&D, GlaxoSmithKline, Severo Ochoa 2, 28760 Tres Cantos, Madrid, Spain
| | - Jose M. Fiandor
- Global Health Medicines R&D, GlaxoSmithKline, Severo Ochoa 2, 28760 Tres Cantos, Madrid, Spain
| | - James H. McKerrow
- Center for Discovery and Innovation in Parasitic Diseases, Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California San Diego, La Jolla, California, United States of America.,Department of Pathology, Sandler Center for Drug Discovery, University of California San Francisco, San Francisco, California, United States of America
| | - Camila I. De Oliveira
- HUPES, Instituto Nacional de Ciência e Tecnologia em Doenças Tropicais (INCT-DT) -Salvador, Brazil; Instituto de Investigação em Imunologia (iii-INCT), São Paulo, Brazil
| | - Jair L. Siqueira-Neto
- Center for Discovery and Innovation in Parasitic Diseases, Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California San Diego, La Jolla, California, United States of America.,Department of Pathology, Sandler Center for Drug Discovery, University of California San Francisco, San Francisco, California, United States of America
| | - Silvia González
- Global Health Medicines R&D, GlaxoSmithKline, Severo Ochoa 2, 28760 Tres Cantos, Madrid, Spain
| | - Lauren E. Brown
- Department of Chemistry and Center for Molecular Discovery (BU-CMD), Boston University, Boston, Massachusetts, United States of America
| | - Scott E. Schaus
- Department of Chemistry and Center for Molecular Discovery (BU-CMD), Boston University, Boston, Massachusetts, United States of America.,Correspondence: Scott E. Schaus,
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He CP, Chen C, Jiang XC, Li H, Zhu LX, Wang PX, Xiao T. The role of AGEs in pathogenesis of cartilage destruction in osteoarthritis. Bone Joint Res 2022; 11:292-300. [PMID: 35549515 PMCID: PMC9130677 DOI: 10.1302/2046-3758.115.bjr-2021-0334.r1] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
Abstract
Osteoarthritis (OA) is a degenerative disease resulting from progressive joint destruction caused by many factors. Its pathogenesis is complex and has not been elucidated to date. Advanced glycation end products (AGEs) are a series of irreversible and stable macromolecular complexes formed by reducing sugar with protein, lipid, and nucleic acid through a non-enzymatic glycosylation reaction (Maillard reaction). They are an important indicator of the degree of ageing. Currently, it is considered that AGEs accumulation in vivo is a molecular basis of age-induced OA, and AGEs production and accumulation in vivo is one of the important reasons for the induction and acceleration of the pathological changes of OA. In recent years, it has been found that AGEs are involved in a variety of pathological processes of OA, including extracellular matrix degradation, chondrocyte apoptosis, and autophagy. Clearly, AGEs play an important role in regulating the expression of OA-related genes and maintaining the chondrocyte phenotype and the stability of the intra-articular environment. This article reviews the latest research results of AGEs in a variety of pathological processes of OA, to provide a new direction for the study of OA pathogenesis and a new target for prevention and treatment. Cite this article: Bone Joint Res 2022;11(5):292–300.
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Affiliation(s)
- Chao-Peng He
- Department of Orthopedics, The Second Xiangya Hospital of Central South University, Changsha, China
| | - Cheng Chen
- Department of Orthopedics, Second Affiliated Hospital of Hunan Normal University, Changsha, China
| | - Xin-Chen Jiang
- The National & Local Joint Engineering Laboratory of Animal Peptide Drug Development, College of Life Sciences, Hunan Normal University, Changsha, China.,Hunan Provincial Key Laboratory of Neurorestoratology, Second Affiliated Hospital of Hunan Normal University, Changsha, China
| | - Hui Li
- Department of Orthopedics, The Second Xiangya Hospital of Central South University, Changsha, China
| | - Li-Xin Zhu
- Department of Orthopedics, Second Affiliated Hospital of Hunan Normal University, Changsha, China
| | - Ping-Xiao Wang
- Department of Orthopedics, The Second Xiangya Hospital of Central South University, Changsha, China
| | - Tao Xiao
- Department of Orthopedics, The Second Xiangya Hospital of Central South University, Changsha, China
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Effects of a Novel GPR55 Antagonist on the Arachidonic Acid Cascade in LPS-Activated Primary Microglial Cells. Int J Mol Sci 2021; 22:ijms22052503. [PMID: 33801492 PMCID: PMC7958845 DOI: 10.3390/ijms22052503] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2021] [Revised: 02/24/2021] [Accepted: 02/25/2021] [Indexed: 11/16/2022] Open
Abstract
Neuroinflammation is a crucial process to maintain homeostasis in the central nervous system (CNS). However, chronic neuroinflammation is detrimental, and it is described in the pathogenesis of CNS disorders, including Alzheimer’s disease (AD) and depression. This process is characterized by the activation of immune cells, mainly microglia. The role of the orphan G-protein-coupled receptor 55 (GPR55) in inflammation has been reported in different models. However, its role in neuroinflammation in respect to the arachidonic acid (AA) cascade in activated microglia is still lacking of comprehension. Therefore, we synthesized a novel GPR55 antagonist (KIT 10, 0.1–25 µM) and tested its effects on the AA cascade in lipopolysaccharide (LPS, 10 ng / mL)-treated primary rat microglia using Western blot and EIAs. We show here that KIT 10 potently prevented the release of prostaglandin E2 (PGE2), reduced microsomal PGE2 synthase (mPGES-1) and cyclooxygenase-2 (COX-2) synthesis, and inhibited the phosphorylation of Ikappa B-alpha (IκB-α), a crucial upstream step of the inflammation-related nuclear factor-kappaB (NF-κB) signaling pathway. However, no effects were observed on COX-1 and -2 activities and mitogen-activated kinases (MAPK). In summary, the novel GPR55 receptor antagonist KIT 10 reduces neuroinflammatory parameters in microglia by inhibiting the COX-2/PGE2 pathway. Further experiments are necessary to better elucidate its effects and mechanisms. Nevertheless, the modulation of inflammation by GPR55 might be a new therapeutic option to treat CNS disorders with a neuroinflammatory background such as AD or depression.
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