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Kaffe E, Tisi A, Magkrioti C, Aidinis V, Mehal WZ, Flavell RA, Maccarrone M. Bioactive signalling lipids as drivers of chronic liver diseases. J Hepatol 2024; 80:140-154. [PMID: 37741346 DOI: 10.1016/j.jhep.2023.08.029] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/15/2023] [Revised: 08/23/2023] [Accepted: 08/28/2023] [Indexed: 09/25/2023]
Abstract
Lipids are important in multiple cellular functions, with most having structural or energy storage roles. However, a small fraction of lipids exert bioactive roles through binding to G protein-coupled receptors and induce a plethora of processes including cell proliferation, differentiation, growth, migration, apoptosis, senescence and survival. Bioactive signalling lipids are potent modulators of metabolism and energy homeostasis, inflammation, tissue repair and malignant transformation. All these events are involved in the initiation and progression of chronic liver diseases. In this review, we focus specifically on the roles of bioactive lipids derived from phospholipids (lyso-phospholipids) and poly-unsaturated fatty acids (eicosanoids, pro-resolving lipid mediators and endocannabinoids) in prevalent chronic liver diseases (alcohol-associated liver disease, non-alcoholic fatty liver disease, viral hepatitis and hepatocellular carcinoma). We discuss the balance between pathogenic and beneficial bioactive lipids as well as potential therapeutic targets related to the agonism or antagonism of their receptors.
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Affiliation(s)
- Eleanna Kaffe
- Department of Immunobiology, Yale University School of Medicine, 06511, New Haven, CT, USA.
| | - Annamaria Tisi
- Department of Biotechnological and Applied Clinical Sciences, University of L'Aquila, 67100, L'Aquila, Italy
| | | | - Vassilis Aidinis
- Biomedical Sciences Research Center Alexander Fleming, 16672, Athens, Greece
| | - Wajahat Z Mehal
- Department of Internal Medicine, Section of Digestive Diseases, Yale University, New Haven, CT, 06520, USA; Veterans Affairs Medical Center, West Haven, CT, 06516, USA
| | - Richard A Flavell
- Department of Immunobiology, Yale University School of Medicine, 06511, New Haven, CT, USA; Howard Hughes Medical Institute, Yale School of Medicine, New Haven, CT, 06519, USA
| | - Mauro Maccarrone
- Department of Biotechnological and Applied Clinical Sciences, University of L'Aquila, 67100, L'Aquila, Italy; Laboratory of Lipid Neurochemistry, European Center for Brain Research (CERC), Santa Lucia Foundation IRCCS, 00143 Rome, Italy.
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2
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Forde B, Yao L, Shaha R, Murphy S, Lunjani N, O'Mahony L. Immunomodulation by foods and microbes: Unravelling the molecular tango. Allergy 2022; 77:3513-3526. [PMID: 35892227 PMCID: PMC10087875 DOI: 10.1111/all.15455] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2022] [Revised: 07/15/2022] [Accepted: 07/23/2022] [Indexed: 01/28/2023]
Abstract
Metabolic health and immune function are intimately connected via diet and the microbiota. Nearly 90% of all immune cells in the body are associated with the gastrointestinal tract and these immune cells are continuously exposed to a wide range of microbes and microbial-derived compounds, with important systemic ramifications. Microbial dysbiosis has consistently been observed in patients with atopic dermatitis, food allergy and asthma and the molecular mechanisms linking changes in microbial populations with disease risk and disease endotypes are being intensively investigated. The discovery of novel bacterial metabolites that impact immune function is at the forefront of host-microbe research. Co-evolution of microbial communities within their hosts has resulted in intertwined metabolic pathways that affect physiological and pathological processes. However, recent dietary and lifestyle changes are thought to negatively influence interactions between microbes and their host. This review provides an overview of some of the critical metabolite-receptor interactions that have been recently described, which may underpin the immunomodulatory effects of the microbiota, and are of relevance for allergy, asthma and infectious diseases.
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Affiliation(s)
- Brian Forde
- APC Microbiome Ireland, UCC, Cork, Ireland.,School of Microbiology, UCC, Cork, Ireland
| | - Lu Yao
- APC Microbiome Ireland, UCC, Cork, Ireland.,School of Microbiology, UCC, Cork, Ireland
| | - Rupin Shaha
- APC Microbiome Ireland, UCC, Cork, Ireland.,School of Microbiology, UCC, Cork, Ireland
| | | | - Nonhlanhla Lunjani
- APC Microbiome Ireland, UCC, Cork, Ireland.,University of Cape Town, Cape Town, South Africa
| | - Liam O'Mahony
- APC Microbiome Ireland, UCC, Cork, Ireland.,School of Microbiology, UCC, Cork, Ireland.,Department of Medicine, UCC, Cork, Ireland
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3
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Wei X, Yin F, Wu M, Xie Q, Zhao X, Zhu C, Xie R, Chen C, Liu M, Wang X, Ren R, Kang G, Zhu C, Cong J, Wang H, Wang X. G protein-coupled receptor 35 attenuates nonalcoholic steatohepatitis by reprogramming cholesterol homeostasis in hepatocytes. Acta Pharm Sin B 2022; 13:1128-1144. [PMID: 36970193 PMCID: PMC10031266 DOI: 10.1016/j.apsb.2022.10.011] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2022] [Revised: 08/08/2022] [Accepted: 08/18/2022] [Indexed: 11/15/2022] Open
Abstract
Nonalcoholic fatty liver disease (NAFLD) is the most common chronic liver disease worldwide. Fat accumulation "sensitizes" the liver to insult and leads to nonalcoholic steatohepatitis (NASH). G protein-coupled receptor 35 (GPR35) is involved in metabolic stresses, but its role in NAFLD is unknown. We report that hepatocyte GPR35 mitigates NASH by regulating hepatic cholesterol homeostasis. Specifically, we found that GPR35 overexpression in hepatocytes protected against high-fat/cholesterol/fructose (HFCF) diet-induced steatohepatitis, whereas loss of GPR35 had the opposite effect. Administration of the GPR35 agonist kynurenic acid (Kyna) suppressed HFCF diet-induced steatohepatitis in mice. Kyna/GPR35 induced expression of StAR-related lipid transfer protein 4 (STARD4) through the ERK1/2 signaling pathway, ultimately resulting in hepatic cholesterol esterification and bile acid synthesis (BAS). The overexpression of STARD4 increased the expression of the BAS rate-limiting enzymes cytochrome P450 family 7 subfamily A member 1 (CYP7A1) and CYP8B1, promoting the conversion of cholesterol to bile acid. The protective effect induced by GPR35 overexpression in hepatocytes disappeared in hepatocyte STARD4-knockdown mice. STARD4 overexpression in hepatocytes reversed the aggravation of HFCF diet-induced steatohepatitis caused by the loss of GPR35 expression in hepatocytes in mice. Our findings indicate that the GPR35-STARD4 axis is a promising therapeutic target for NAFLD.
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Affiliation(s)
- Xiaoli Wei
- Department of Oncology, the First Affiliated Hospital of Anhui Medical University, Hefei 230036, China
| | - Fan Yin
- Department of Pharmacy, Huainan First People's Hospital, the First Affiliated Hospital of Anhui University of Science and Technology, Huainan 232001, China
- School of Pharmacy, Anhui Medical University, Hefei 230032, China
| | - Miaomiao Wu
- Department of Oncology, the First Affiliated Hospital of Anhui Medical University, Hefei 230036, China
- School of Pharmacy, Anhui Medical University, Hefei 230032, China
| | - Qianqian Xie
- School of Pharmacy, Anhui Medical University, Hefei 230032, China
- Inflammation and Immune Mediated Diseases Laboratory of Anhui Province, Anhui Medical University, Hefei 230032, China
| | - Xueqin Zhao
- School of Pharmacy, Anhui Medical University, Hefei 230032, China
- Inflammation and Immune Mediated Diseases Laboratory of Anhui Province, Anhui Medical University, Hefei 230032, China
| | - Cheng Zhu
- Department of Oncology, the First Affiliated Hospital of Anhui Medical University, Hefei 230036, China
| | - Ruiqian Xie
- School of Pharmacy, Anhui Medical University, Hefei 230032, China
- Inflammation and Immune Mediated Diseases Laboratory of Anhui Province, Anhui Medical University, Hefei 230032, China
| | - Chongqing Chen
- School of Pharmacy, Anhui Medical University, Hefei 230032, China
- Inflammation and Immune Mediated Diseases Laboratory of Anhui Province, Anhui Medical University, Hefei 230032, China
| | - Menghua Liu
- School of Pharmacy, Anhui Medical University, Hefei 230032, China
- Inflammation and Immune Mediated Diseases Laboratory of Anhui Province, Anhui Medical University, Hefei 230032, China
| | - Xueying Wang
- Department of Oncology, the First Affiliated Hospital of Anhui Medical University, Hefei 230036, China
| | - Ruixue Ren
- Department of Oncology, the First Affiliated Hospital of Anhui Medical University, Hefei 230036, China
| | - Guijie Kang
- School of Pharmacy, Anhui Medical University, Hefei 230032, China
- Inflammation and Immune Mediated Diseases Laboratory of Anhui Province, Anhui Medical University, Hefei 230032, China
| | - Chenwen Zhu
- Department of Oncology, the First Affiliated Hospital of Anhui Medical University, Hefei 230036, China
| | - Jingjing Cong
- School of Pharmacy, Anhui Medical University, Hefei 230032, China
- Inflammation and Immune Mediated Diseases Laboratory of Anhui Province, Anhui Medical University, Hefei 230032, China
| | - Hua Wang
- Department of Oncology, the First Affiliated Hospital of Anhui Medical University, Hefei 230036, China
- Inflammation and Immune Mediated Diseases Laboratory of Anhui Province, Anhui Medical University, Hefei 230032, China
- Corresponding authors.
| | - Xuefu Wang
- School of Pharmacy, Anhui Medical University, Hefei 230032, China
- Inflammation and Immune Mediated Diseases Laboratory of Anhui Province, Anhui Medical University, Hefei 230032, China
- Corresponding authors.
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4
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Foresight regarding drug candidates acting on the succinate-GPR91 signalling pathway for non-alcoholic steatohepatitis (NASH) treatment. Biomed Pharmacother 2021; 144:112298. [PMID: 34649219 DOI: 10.1016/j.biopha.2021.112298] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2021] [Revised: 09/29/2021] [Accepted: 10/05/2021] [Indexed: 11/24/2022] Open
Abstract
Non-alcoholic fatty liver disease (NAFLD) is the most common chronic liver disease, and it is a liver manifestation of metabolic syndrome, with a histological spectrum from simple steatosis to non-alcoholic steatohepatitis (NASH). NASH can evolve into progressive liver fibrosis and eventually lead to liver cirrhosis. The pathological mechanism of NASH is multifactorial, involving a series of metabolic disorders and changes that trigger low-level inflammation in the liver and other organs. In the pathogenesis of NASH, the signal transduction pathway involving succinate and the succinate receptor (G-protein-coupled receptor 91, GPR91) regulates inflammatory cell activation and liver fibrosis. This review describes the mechanism of the succinate-GPR91 signalling pathway in NASH and summarizes the drugs that act on this pathway, with the aim of providing a new approach to NASH treatment.
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5
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Cui X, Xing R, Tian Y, Wang M, Sun Y, Xu Y, Yang Y, Zhao Y, Xie L, Xiao Y, Li D, Zheng B, Liu M, Chen H. The G2A Receptor Deficiency Aggravates Atherosclerosis in Rats by Regulating Macrophages and Lipid Metabolism. Front Physiol 2021; 12:659211. [PMID: 34381373 PMCID: PMC8351205 DOI: 10.3389/fphys.2021.659211] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2021] [Accepted: 04/13/2021] [Indexed: 11/16/2022] Open
Abstract
The orphan G protein-coupled receptor G2A has been linked to atherosclerosis development. However, available data from mouse models are controversial. Rat G2A receptor bears more similarities with its human homolog. We proposed that the atherosclerosis model established from Ldlr–/– rat, which has been reported to share more similar phenotypes with the human disease, may help to further understand this lipid receptor. G2A deletion was found markedly aggravated in the lipid disorder in the rat model, which has not been reported in mouse studies. Examination of aortas revealed exacerbated atherosclerotic plaques in G2A deficient rats, together with increased oxidative stress and macrophage accumulation. In addition, consistently promoted migration and apoptosis were noticed in G2A deficient macrophages, even in macrophages from G2A single knockout rats. Further analysis found significantly declined phosphorylation of PI3 kinase (PI3K) and AKT, together with reduced downstream genes Bcl2 and Bcl-xl, suggesting possible involvement of PI3K/AKT pathway in G2A regulation to macrophage apoptosis. These data indicate that G2A modulates atherosclerosis by regulating lipid metabolism and macrophage migration and apoptosis. Our study provides a new understanding of the role of G2A in atherosclerosis, supporting it as a potential therapeutic target.
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Affiliation(s)
- Xueqin Cui
- Shanghai Key Laboratory of Regulatory Biology, School of Life Sciences, Institute of Biomedical Sciences, East China Normal University, Shanghai, China
| | - Roumei Xing
- Shanghai Key Laboratory of Regulatory Biology, School of Life Sciences, Institute of Biomedical Sciences, East China Normal University, Shanghai, China
| | - Yue Tian
- Shanghai Key Laboratory of Regulatory Biology, School of Life Sciences, Institute of Biomedical Sciences, East China Normal University, Shanghai, China
| | - Man Wang
- Shanghai Key Laboratory of Regulatory Biology, School of Life Sciences, Institute of Biomedical Sciences, East China Normal University, Shanghai, China
| | - Yue Sun
- Shanghai Key Laboratory of Regulatory Biology, School of Life Sciences, Institute of Biomedical Sciences, East China Normal University, Shanghai, China
| | - Yongqian Xu
- Shanghai Key Laboratory of Regulatory Biology, School of Life Sciences, Institute of Biomedical Sciences, East China Normal University, Shanghai, China
| | - Yiqing Yang
- Shanghai Key Laboratory of Regulatory Biology, School of Life Sciences, Institute of Biomedical Sciences, East China Normal University, Shanghai, China
| | - Yongliang Zhao
- Shanghai Key Laboratory of Regulatory Biology, School of Life Sciences, Institute of Biomedical Sciences, East China Normal University, Shanghai, China
| | - Ling Xie
- Shanghai Key Laboratory of Regulatory Biology, School of Life Sciences, Institute of Biomedical Sciences, East China Normal University, Shanghai, China
| | - Yufang Xiao
- Shanghai Key Laboratory of Regulatory Biology, School of Life Sciences, Institute of Biomedical Sciences, East China Normal University, Shanghai, China
| | - Dali Li
- Shanghai Key Laboratory of Regulatory Biology, School of Life Sciences, Institute of Biomedical Sciences, East China Normal University, Shanghai, China
| | - Biao Zheng
- Shanghai Key Laboratory of Regulatory Biology, School of Life Sciences, Institute of Biomedical Sciences, East China Normal University, Shanghai, China.,Department of Pathology & Immunology, Baylor College of Medicine, Houston, TX, United States
| | - Mingyao Liu
- Shanghai Key Laboratory of Regulatory Biology, School of Life Sciences, Institute of Biomedical Sciences, East China Normal University, Shanghai, China
| | - Huaqing Chen
- Shanghai Key Laboratory of Regulatory Biology, School of Life Sciences, Institute of Biomedical Sciences, East China Normal University, Shanghai, China
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6
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Yang M, Zhang CY. G protein-coupled receptors as potential targets for nonalcoholic fatty liver disease treatment. World J Gastroenterol 2021; 27:677-691. [PMID: 33716447 PMCID: PMC7934005 DOI: 10.3748/wjg.v27.i8.677] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/11/2020] [Revised: 12/24/2020] [Accepted: 01/21/2021] [Indexed: 02/06/2023] Open
Abstract
Nonalcoholic fatty liver disease (NAFLD) is a broad-spectrum disease, ranging from simple hepatic steatosis to nonalcoholic steatohepatitis, which can progress to cirrhosis and liver cancer. Abnormal hepatic lipid accumulation is the major manifestation of this disease, and lipotoxicity promotes NAFLD progression. In addition, intermediate metabolites such as succinate can stimulate the activation of hepatic stellate cells to produce extracellular matrix proteins, resulting in progression of NAFLD to fibrosis and even cirrhosis. G protein-coupled receptors (GPCRs) have been shown to play essential roles in metabolic disorders, such as NAFLD and obesity, through their function as receptors for bile acids and free fatty acids. In addition, GPCRs link gut microbiota-mediated connections in a variety of diseases, such as intestinal diseases, hepatic steatosis, diabetes, and cardiovascular diseases. The latest findings show that gut microbiota-derived acetate contributes to liver lipogenesis by converting dietary fructose into hepatic acetyl-CoA and fatty acids. GPCR agonists, including peptides and natural products like docosahexaenoic acid, have been applied to investigate their role in liver diseases. Therapies such as probiotics and GPCR agonists may be applied to modulate GPCR function to ameliorate liver metabolism syndrome. This review summarizes the current findings regarding the role of GPCRs in the development and progression of NAFLD and describes some preclinical and clinical studies of GPCR-mediated treatment. Overall, understanding GPCR-mediated signaling in liver disease may provide new therapeutic options for NAFLD.
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Affiliation(s)
- Ming Yang
- Department of Surgery, University of Missouri, Columbia, MO 65212, United States
| | - Chun-Ye Zhang
- Department of Veterinary Pathobiology, University of Missouri, Columbia, MO 65212, United States
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7
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Xu G, Li Y, Jiang X, Chen H. CAV1 Prevents Gallbladder Cholesterol Crystallization by Regulating Biosynthesis and Transport of Bile Salts. J Cell Biochem 2016; 117:2118-27. [PMID: 26875794 DOI: 10.1002/jcb.25518] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2015] [Accepted: 02/11/2016] [Indexed: 12/25/2022]
Affiliation(s)
- Guoqiang Xu
- Department of Gastroenterology; Zhejiang University School of Medicine; The First Affiliated Hospital; Hangzhou Zhejiang 310003 China
| | - Yiqiao Li
- Department of Nephrology; Zhejiang Province People's Hospital; Hangzhou Zhejiang 310014 China
| | - Xin Jiang
- Department of Pathology and Pathophysiology; Zhejiang University School of Medicine; Hangzhou Zhejiang 310058 China
| | - Hongtan Chen
- Department of Gastroenterology; Zhejiang University School of Medicine; The First Affiliated Hospital; Hangzhou Zhejiang 310003 China
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8
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Im DS. Intercellular Lipid Mediators and GPCR Drug Discovery. Biomol Ther (Seoul) 2014; 21:411-22. [PMID: 24404331 PMCID: PMC3879912 DOI: 10.4062/biomolther.2013.080] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2013] [Revised: 10/30/2013] [Accepted: 11/04/2013] [Indexed: 01/08/2023] Open
Abstract
G-protein-coupled receptors (GPCR) are the largest superfamily of receptors responsible for signaling between cells and tissues, and because they play important physiological roles in homeostasis, they are major drug targets. New technologies have been developed for the identification of new ligands, new GPCR functions, and for drug discovery purposes. In particular, intercellular lipid mediators, such as, lysophosphatidic acid and sphingosine 1-phosphate have attracted much attention for drug discovery and this has resulted in the development of fingolimod (FTY-720) and AM095. The discovery of new intercellular lipid mediators and their GPCRs are discussed from the perspective of drug development. Lipid GPCRs for lysophospholipids, including lysophosphatidylserine, lysophosphatidylinositol, lysophosphatidylcholine, free fatty acids, fatty acid derivatives, and other lipid mediators are reviewed.
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Affiliation(s)
- Dong-Soon Im
- Molecular Inflammation Research Center for Aging Intervention (MRCA) and College of Pharmacy, Pusan National University, Busan 609-735, Republic of Korea
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Vangaveti V, Shashidhar V, Jarrod G, Baune BT, Kennedy RL. Free fatty acid receptors: emerging targets for treatment of diabetes and its complications. Ther Adv Endocrinol Metab 2010; 1:165-75. [PMID: 23148161 PMCID: PMC3474614 DOI: 10.1177/2042018810381066] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
Fatty acids (FAs) are important as metabolic substrates and as structural components of biological membranes. However, they also function as signalling molecules. Recently, a series of G protein-coupled receptors (GPRs) for FAs has been described and characterized. These receptors have differing specificities for FAs of differing chain length and degree of saturation, for FA derivatives such as oleoylethanolamide, and for oxidized FAs. They are a critical component of the body's nutrient sensing apparatus, and small molecule agonists and antagonists of these receptors show considerable promise in the management of diabetes and its complications. Agonists of the long-chain free fatty acid receptors FFAR1 and GPR119 act as insulin secretagogues, both directly and by increasing incretins. Although, drugs acting at short-chain FFA receptors (FFAR2 and FFAR3) have not yet been developed, they are attractive targets as they regulate nutrient balance through effects in the intestine and adipose tissue. These include regulation of the secretion of cholecystokinin, peptide YY and leptin. Finally, GPR132 is a receptor for oxidized FAs, which may be a sensor of lipid overload and oxidative stress, and which is involved in atherosclerosis. Regulation of its signalling pathways with drugs may decrease the macrovascular risk experienced by diabetic patients. In summary, FA receptors are emerging drug targets that are involved in the regulation of nutrient status and carbohydrate tolerance, and modulators of these receptors may well figure prominently in the next generation of antidiabetic drugs.
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Affiliation(s)
- Venkat Vangaveti
- Venkat Vangaveti, MSc Ghassan Jarrod, MBChB, FRACP Department of Pathology, School of Medicine and Dentistry, James Cook University, Townsville, Queensland 4811, Australia
| | - Venkatesh Shashidhar
- Venkatesh Shashidhar, BSc, MBBS, MD Department of Medicine, School of Medicine and Dentistry, James Cook University, Townsville, Queensland 4811 Australia
| | - Ghassan Jarrod
- Venkat Vangaveti, MSc Ghassan Jarrod, MBChB, FRACP Department of Pathology, School of Medicine and Dentistry, James Cook University, Townsville, Queensland 4811, Australia
| | - Bernhard T. Baune
- Bernhard T. Baune, MD, PhD Department of Psychiatry and Psychiatric Neuroscience, School of Medicine and Dentistry, James Cook University, Townsville, Queensland 4811 Australia
| | - R. Lee Kennedy
- Correspondence to: R. Lee Kennedy, MD, PhD, FRCP, FRACP Department of Medicine, School of Medicine and Dentistry, James Cook University, Townsville, Queensland 4811, Australia
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10
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Abstract
A large number of new therapies are in development for chronic hepatitis C including direct-acting antiviral drugs (DAA), which target specific hepatitis C virus enzymes. Two of these compounds have already advanced into phase 3 development in the USA and EU, and many more are in phase 2 trials and likely to advance. In this review, the results of recent studies on ribavirin analogues, nonstructural (NS) 3/4 serine protease inhibitors, NS5B polymerase inhibitors, cyclophilin inhibitors, silimarin components, and thiazolides have been updated. Each compound includes a brief summary of its proposed mechanism of action, results of early clinical trials, and more advanced trial data where available. These compounds are likely to be the first approved in the USA and EU and will initially be used in combination with the current standard of care. It is possible that future treatment paradigms with these agents will offer the potential of interferon-free regimens. It is most likely that patients for these new therapies will be selected carefully by identifying and treating first those who have excellent sustained virologic response rates with 24 weeks of pegylated interferon and ribavirin, the current standard of care. It is also likely that there will be a need to identify those patients who are not likely to have a sustained virologic response with the addition of a protease inhibitor to the current standard of care and delaying their therapy until combination viral suppression therapy becomes an option. The cost and side effects of the DAA will be important considerations for treating physicians. This review is current through 2009; however, data are rapidly changing.
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Affiliation(s)
- Paul J. Pockros
- Head, Division of Gastroenterology/Hepatology,
Scripps Clinic, 10666 N Torrey Pines Road, La Jolla, CA 92037, USA
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11
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Li H, Wang D, Singh LS, Berk M, Tan H, Zhao Z, Steinmetz R, Kirmani K, Wei G, Xu Y. Abnormalities in osteoclastogenesis and decreased tumorigenesis in mice deficient for ovarian cancer G protein-coupled receptor 1. PLoS One 2009; 4:e5705. [PMID: 19479052 PMCID: PMC2684630 DOI: 10.1371/journal.pone.0005705] [Citation(s) in RCA: 67] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2009] [Accepted: 05/05/2009] [Indexed: 12/13/2022] Open
Abstract
Ovarian cancer G protein-coupled receptor 1 (OGR1) has been shown to be a proton sensing receptor in vitro. We have shown that OGR1 functions as a tumor metastasis suppressor gene when it is over-expressed in human prostate cancer cells in vivo. To examine the physiological functions of OGR1, we generated conditional OGR1 deficient mice by homologous recombination. OGR1 deficient mice were viable and upon gross-inspection appeared normal. Consistent with in vitro studies showing that OGR1 is involved in osteoclastogenesis, reduced osteoclasts were detected in OGR1 deficient mice. A pH-dependent osteoclasts survival effect was also observed. However, overall abnormality in the bones of these animals was not observed. In addition, melanoma cell tumorigenesis was significantly inhibited in OGR1 deficient mice. OGR1 deficient mice in the mixed background produced significantly less peritoneal macrophages when stimulated with thioglycolate. These macrophages also showed altered extracellular signal-regulated kinases (ERK) activation and nitric oxide (NO) production in response to lipopolysaccharide. OGR1-dependent pH responses assessed by cAMP production and cell survival in macrophages or brown fat cells were not observed, presumably due to the presence of other proton sensing receptors in these cells. Our results indicate that OGR1's role in osteoclastogenesis is not strong enough to affect overall bone development and its role in tumorigenesis warrants further investigation. The mice generated can be potentially used for several disease models, including cancers or osteoclast-related diseases.
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Affiliation(s)
- Hui Li
- Department of Obstetrics and Gynecology, Indiana University Cancer Center, Indiana University School of Medicine, Indianapolis, Indiana, United States of America
- Department of Cancer Biology, Lerner Research Institute, Cleveland Clinic, Cleveland, Ohio, United States of America
| | - Dongmei Wang
- Department of Obstetrics and Gynecology, Indiana University Cancer Center, Indiana University School of Medicine, Indianapolis, Indiana, United States of America
| | - Lisam Shanjukumar Singh
- Department of Obstetrics and Gynecology, Indiana University Cancer Center, Indiana University School of Medicine, Indianapolis, Indiana, United States of America
- Department of Cancer Biology, Lerner Research Institute, Cleveland Clinic, Cleveland, Ohio, United States of America
- Department of Biotechnology, Manipur University, Canchipur, Manipur, India
| | - Michael Berk
- Department of Cancer Biology, Lerner Research Institute, Cleveland Clinic, Cleveland, Ohio, United States of America
| | - Haiyan Tan
- Department of Cancer Biology, Lerner Research Institute, Cleveland Clinic, Cleveland, Ohio, United States of America
| | - Zhenwen Zhao
- Department of Obstetrics and Gynecology, Indiana University Cancer Center, Indiana University School of Medicine, Indianapolis, Indiana, United States of America
- Department of Cancer Biology, Lerner Research Institute, Cleveland Clinic, Cleveland, Ohio, United States of America
| | - Rosemary Steinmetz
- Department of Obstetrics and Gynecology, Indiana University Cancer Center, Indiana University School of Medicine, Indianapolis, Indiana, United States of America
| | - Kashif Kirmani
- Department of Obstetrics and Gynecology, Indiana University Cancer Center, Indiana University School of Medicine, Indianapolis, Indiana, United States of America
| | - Gang Wei
- Department of Obstetrics and Gynecology, Indiana University Cancer Center, Indiana University School of Medicine, Indianapolis, Indiana, United States of America
| | - Yan Xu
- Department of Obstetrics and Gynecology, Indiana University Cancer Center, Indiana University School of Medicine, Indianapolis, Indiana, United States of America
- * E-mail:
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12
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Bolick DT, Skaflen MD, Johnson LE, Kwon SC, Howatt D, Daugherty A, Ravichandran KS, Hedrick CC. G2A deficiency in mice promotes macrophage activation and atherosclerosis. Circ Res 2008; 104:318-27. [PMID: 19106413 DOI: 10.1161/circresaha.108.181131] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
G2A is a stress-inducible G protein-coupled receptor that is expressed on several cell types within atherosclerotic lesions. We demonstrated previously that G2A deficiency in mice increased aortic monocyte recruitment and increased monocyte:endothelial interactions. To investigate the impact of G2A deficiency in macrophages, we isolated peritoneal macrophages from G2A(+/+)ApoE(-/-) and G2A(-/-)ApoE(-/-) mice. G2A(-/-)ApoE(-/-) macrophages had significantly lower apoptosis than control macrophages. The prosurvival genes BCL-2, BCL-xL, and cFLIP were increased in G2A(-/-)ApoE(-/-) macrophages. Macrophages from G2A(-/-)ApoE(-/-) mice also had increased proinflammatory status that was indicative of a M1 macrophage phenotype. This was indicated by significantly increased nuclear translocation of nuclear factor kappaB, as well as production of interleukin-12p40, tumor necrosis factor alpha, and interleukin-6, and reduced expression of arginase-I. Moreover, G2A(-/-)ApoE(-/-) macrophages had reduced ability to engulf apoptotic cells in vitro. We examined atherosclerosis in mice fed a Western diet for 10 weeks and found that G2A deficiency increased lesion size in the aortic root by 50%. Plasma lipid levels were not changed in G2A(-/-)ApoE(-/-) mice. However, we found that absence of G2A increased the number of aortic macrophages and attenuated apoptosis in this cell type. Moreover, bone marrow transplantation studies indicated that deficiency of G2A in marrow-derived cells significantly contributed to atherosclerosis development. In the absence of G2A, increased macrophage activation and decreased apoptosis is associated with accumulation of macrophages in the aorta and increased atherosclerosis.
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Affiliation(s)
- David T Bolick
- Cardiovascular Research Center, University of Charlottesville, Charlottesville, Virginia 22908, USA
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