1
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Hausmann M, Seuwen K, de Vallière C, Busch M, Ruiz PA, Rogler G. Role of pH-sensing receptors in colitis. Pflugers Arch 2024; 476:611-622. [PMID: 38514581 PMCID: PMC11006753 DOI: 10.1007/s00424-024-02943-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2023] [Revised: 03/06/2024] [Accepted: 03/06/2024] [Indexed: 03/23/2024]
Abstract
Low pH in the gut is associated with severe inflammation, fibrosis, and colorectal cancer (CRC) and is a hallmark of active inflammatory bowel disease (IBD). Subsequently, pH-sensing mechanisms are of interest for the understanding of IBD pathophysiology. Tissue hypoxia and acidosis-two contributing factors to disease pathophysiology-are linked to IBD, and understanding their interplay is highly relevant for the development of new therapeutic options. One member of the proton-sensing G protein-coupled receptor (GPCR) family, GPR65 (T-cell death-associated gene 8, TDAG8), was identified as a susceptibility gene for IBD in a large genome-wide association study. In response to acidic extracellular pH, GPR65 induces an anti-inflammatory response, whereas the two other proton-sensing receptors, GPR4 and GPR68 (ovarian cancer G protein-coupled receptor 1, OGR1), mediate pro-inflammatory responses. Here, we review the current knowledge on the role of these proton-sensing receptors in IBD and IBD-associated fibrosis and cancer, as well as colitis-associated cancer (CAC). We also describe emerging small molecule modulators of these receptors as therapeutic opportunities for the treatment of IBD.
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Affiliation(s)
- Martin Hausmann
- Department of Gastroenterology and Hepatology, University Hospital Zurich, University of Zurich, 8091, Zurich, CH, Switzerland.
| | - Klaus Seuwen
- Department of Gastroenterology and Hepatology, University Hospital Zurich, University of Zurich, 8091, Zurich, CH, Switzerland
| | - Cheryl de Vallière
- Department of Gastroenterology and Hepatology, University Hospital Zurich, University of Zurich, 8091, Zurich, CH, Switzerland
| | - Moana Busch
- Department of Gastroenterology and Hepatology, University Hospital Zurich, University of Zurich, 8091, Zurich, CH, Switzerland
| | - Pedro A Ruiz
- Department of Gastroenterology and Hepatology, University Hospital Zurich, University of Zurich, 8091, Zurich, CH, Switzerland
| | - Gerhard Rogler
- Department of Gastroenterology and Hepatology, University Hospital Zurich, University of Zurich, 8091, Zurich, CH, Switzerland
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2
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Wang H, Xia H, Wang D, Guo Y, Wang X, Yu Y, Zhang C, Liu, Z. Serum lipoprotein phospholipase A2 level has diagnostic value for cognitive impairment in type II diabetes patients with white matter hyperintensity. ALL LIFE 2022. [DOI: 10.1080/26895293.2022.2101550] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022] Open
Affiliation(s)
- Haipeng Wang
- Department of Neurology, the First Affiliated Hospital of Qiqihar Medical University, 26 Xiangyang Street, Qiqihar 161041, People’s Republic of China
| | - Haimiao Xia
- Department of Neurology, the First Affiliated Hospital of Qiqihar Medical University, 26 Xiangyang Street, Qiqihar 161041, People’s Republic of China
| | - Dongxia Wang
- Department of Neurology, the First Affiliated Hospital of Qiqihar Medical University, 26 Xiangyang Street, Qiqihar 161041, People’s Republic of China
| | - Yu Guo
- Department of Neurology, the First Affiliated Hospital of Qiqihar Medical University, 26 Xiangyang Street, Qiqihar 161041, People’s Republic of China
| | - Xiaoyu Wang
- Department of Neurology, the First Affiliated Hospital of Qiqihar Medical University, 26 Xiangyang Street, Qiqihar 161041, People’s Republic of China
| | - Yue Yu
- Department of Neurology, the First Affiliated Hospital of Qiqihar Medical University, 26 Xiangyang Street, Qiqihar 161041, People’s Republic of China
| | - Chengshi Zhang
- Department of Neurology, the First Affiliated Hospital of Qiqihar Medical University, 26 Xiangyang Street, Qiqihar 161041, People’s Republic of China
| | - Zhongjin Liu,
- Department of Neurology, the First Affiliated Hospital of Qiqihar Medical University, 26 Xiangyang Street, Qiqihar 161041, People’s Republic of China
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3
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Richard VR, Gaither C, Popp R, Chaplygina D, Brzhozovskiy A, Kononikhin A, Mohammed Y, Zahedi RP, Nikolaev EN, Borchers CH. Early Prediction of COVID-19 Patient Survival by Targeted Plasma Multi-Omics and Machine Learning. Mol Cell Proteomics 2022; 21:100277. [PMID: 35931319 PMCID: PMC9345792 DOI: 10.1016/j.mcpro.2022.100277] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2021] [Revised: 07/05/2022] [Accepted: 07/27/2022] [Indexed: 01/18/2023] Open
Abstract
The recent surge of coronavirus disease 2019 (COVID-19) hospitalizations severely challenges healthcare systems around the globe and has increased the demand for reliable tests predictive of disease severity and mortality. Using multiplexed targeted mass spectrometry assays on a robust triple quadrupole MS setup which is available in many clinical laboratories, we determined the precise concentrations of hundreds of proteins and metabolites in plasma from hospitalized COVID-19 patients. We observed a clear distinction between COVID-19 patients and controls and, strikingly, a significant difference between survivors and nonsurvivors. With increasing length of hospitalization, the survivors' samples showed a trend toward normal concentrations, indicating a potential sensitive readout of treatment success. Building a machine learning multi-omic model that considers the concentrations of 10 proteins and five metabolites, we could predict patient survival with 92% accuracy (area under the receiver operating characteristic curve: 0.97) on the day of hospitalization. Hence, our standardized assays represent a unique opportunity for the early stratification of hospitalized COVID-19 patients.
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Key Words
- acd, acid citrate dextrose
- acn, acetonitrile
- auc, area under the receiver operating characteristic curve
- bqc19, biobanque quebecoise de la covid-19
- bsa, bovine serum albumin covid-19
- cptac, clinical proteomic tumor analysis consortium
- dtt, dithiothreitol
- fa, formic acid
- fdr, false discovery rate
- icu, intensive care unit
- lc/mrm-ms, liquid chromatography/multiple reaction monitoring mass spectrometry
- lc-ms, liquid chromatography-mass spectrometry
- lloq, lower limit of quantitation
- lysopc, lysophosphatidylcholine
- maldi, matrix-assisted laser desorption ionization
- meoh, methanol
- ms, mass spectrometry
- pbs, phosphatase buffered saline
- pcr, polymerase chain reaction
- pitc, phenylisothiocyanate
- qc, quality control
- rp-uhplc, reversed phase ultrahigh performance liquid chromatography
- sis, stable-isotope-labeled internal standard
- spe, solid-phase extraction
- svm, support vector machine
- trishcl, tris (hydroxymethyl) aminomethane hydrochloride
- uniprot, the universal protein resource
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Affiliation(s)
- Vincent R. Richard
- Segal Cancer Proteomics Centre, Lady Davis Institute for Medical Research, McGill University, Montreal, Quebec, Canada
| | | | | | - Daria Chaplygina
- Center for Molecular and Cellular Biology, Skolkovo Institute of Science and Technology, Moscow, Russia
| | - Alexander Brzhozovskiy
- Center for Molecular and Cellular Biology, Skolkovo Institute of Science and Technology, Moscow, Russia
| | - Alexey Kononikhin
- Center for Molecular and Cellular Biology, Skolkovo Institute of Science and Technology, Moscow, Russia
| | - Yassene Mohammed
- Center for Proteomics and Metabolomics, Leiden University Medical Center, Leiden, the Netherlands,Genome BC Proteomics Centre, University of Victoria, Victoria, Canada
| | - René P. Zahedi
- Segal Cancer Proteomics Centre, Lady Davis Institute for Medical Research, McGill University, Montreal, Quebec, Canada,Manitoba Centre for Proteomics & Systems Biology, John Buhler Research Centre, University of Manitoba, Winnipeg, Canada,Department of Internal Medicine, University of Manitoba, Winnipeg, Canada
| | - Evgeny N. Nikolaev
- Center for Molecular and Cellular Biology, Skolkovo Institute of Science and Technology, Moscow, Russia
| | - Christoph H. Borchers
- Segal Cancer Proteomics Centre, Lady Davis Institute for Medical Research, McGill University, Montreal, Quebec, Canada,Gerald Bronfman Department of Oncology, Division of Experimental Medicine, Lady Davis Institute for Medical Research, McGill University, Montreal, Canada,Department of Pathology, McGill University, Montreal, Canada,For correspondence: Christoph H. Borchers
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4
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Zhang Q, Zhang W, Liu J, Yang H, Hu Y, Zhang M, Bai T, Chang F. Lysophosphatidylcholine promotes intercellular adhesion molecule-1 and vascular cell adhesion molecule-1 expression in human umbilical vein endothelial cells via an orphan G protein receptor 2-mediated signaling pathway. Bioengineered 2021; 12:4520-4535. [PMID: 34346841 PMCID: PMC8806654 DOI: 10.1080/21655979.2021.1956671] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
The oxLDL-based bioactive lipid lysophosphatidylcholine (LPC) is a key regulator of physiological processes including endothelial cell adhesion marker expression. This study explored the relationship between LPC and the human umbilical vein endothelial cell expression of intercellular adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule-1 (VCAM-1) with a particular focus on the regulation of the LPC-G2A-ICAM-1/VCAM-1 pathway in this context. We explored the LPC-inducible role of orphan G protein receptor 2 (G2A) in associated regulatory processes by using human kidney epithelial (HEK293) cells that had been transfected with pET-G2A, human umbilical vein endothelial cells (HUVECs) in which an shRNA was used to knock down G2A, and western blotting and qPCR assays that were used to confirm changes in gene expression. For in vivo studies, a rabbit model of atherosclerosis was established, with serum biochemistry and histological staining approaches being used to assess pathological outcomes in these animals. The treatment of both HEK293 cells and HUVECs with LPC promoted ICAM-1 and VCAM-1 upregulation, while incubation at a pH of 6.8 suppressed such LPC-induced adhesion marker expression. Knocking down G2A by shRNA and inhibiting NF-κB activity yielded opposite outcomes. The application of a Gi protein inhibitor had no impact on LPC-induced ICAM-1/VCAM-1 expression. Atherosclerotic model exhibited high circulating LDL and LPC levels as well as high aortic wall ICAM-1/VCAM-1 expression. Overall, these results suggested that the LPC-G2A-ICAM-1/VCAM-1 pathway may contribute to the atherogenic activity of oxLDL, with NF-κB antagonists representing potentially viable therapeutic tools for the treatment of cardiovascular disease.
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Affiliation(s)
- Qian Zhang
- The Center for New Drug Safety Evaluation and Research, Inner Mongolia Medical University, Hohhot, China.,The Center for New Drug Screening Engineering and Research of Inner Mongolia Autonomous Region, Inner Mongolia Medical University, Hohhot, China.,College of Pharmacy, Inner Mongolia Medical University, Hohhot, China
| | - Wei Zhang
- The Center for New Drug Safety Evaluation and Research, Inner Mongolia Medical University, Hohhot, China.,The Center for New Drug Screening Engineering and Research of Inner Mongolia Autonomous Region, Inner Mongolia Medical University, Hohhot, China.,College of Pharmacy, Inner Mongolia Medical University, Hohhot, China
| | - Jing Liu
- The Center for New Drug Safety Evaluation and Research, Inner Mongolia Medical University, Hohhot, China.,The Center for New Drug Screening Engineering and Research of Inner Mongolia Autonomous Region, Inner Mongolia Medical University, Hohhot, China.,College of Pharmacy, Inner Mongolia Medical University, Hohhot, China
| | - Haisen Yang
- First Clinical Medical College, Inner Mongolia Medical University, Hohhot, China
| | - Yuxia Hu
- The Center for New Drug Safety Evaluation and Research, Inner Mongolia Medical University, Hohhot, China.,The Center for New Drug Screening Engineering and Research of Inner Mongolia Autonomous Region, Inner Mongolia Medical University, Hohhot, China.,College of Pharmacy, Inner Mongolia Medical University, Hohhot, China
| | - Mengdi Zhang
- College of Pharmacy, Inner Mongolia Medical University, Hohhot, China
| | - Tuya Bai
- College of Pharmacy, Inner Mongolia Medical University, Hohhot, China
| | - Fuhou Chang
- The Center for New Drug Safety Evaluation and Research, Inner Mongolia Medical University, Hohhot, China.,The Center for New Drug Screening Engineering and Research of Inner Mongolia Autonomous Region, Inner Mongolia Medical University, Hohhot, China.,College of Pharmacy, Inner Mongolia Medical University, Hohhot, China
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5
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Connection between the Altered HDL Antioxidant and Anti-Inflammatory Properties and the Risk to Develop Alzheimer's Disease: A Narrative Review. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2021; 2021:6695796. [PMID: 33505588 PMCID: PMC7811424 DOI: 10.1155/2021/6695796] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/23/2020] [Revised: 12/21/2020] [Accepted: 12/26/2020] [Indexed: 02/06/2023]
Abstract
The protein composition of high-density lipoprotein (HDL) is extremely fluid. The quantity and quality of protein constituents drive the multiple biological functions of these lipoproteins, which include the ability to contrast atherogenesis, sustained inflammation, and toxic effects of reactive species. Several diseases where inflammation and oxidative stress participate in the pathogenetic process are characterized by perturbation in the HDL proteome. This change inevitably affects the functionality of the lipoprotein. An enlightening example in this frame comes from the literature on Alzheimer's disease (AD). Growing lines of epidemiological evidence suggest that loss of HDL-associated proteins, such as lipoprotein phospholipase A2 (Lp-PLA2), glutathione peroxidase-3 (GPx-3), and paraoxonase-1 and paraoxonase-3 (PON1, PON3), may be a feature of AD, even at the early stage. Moreover, the decrease in these enzymes with antioxidant/defensive action appears to be accompanied by a parallel increase of prooxidant and proinflammatory mediators, in particular myeloperoxidase (MPO) and serum amyloid A (SAA). This type of derangement of balance between two opposite forces makes HDL dysfunctional, i.e., unable to exert its “natural” vasculoprotective property. In this review, we summarized and critically analyzed the most significant findings linking HDL accessory proteins and AD. We also discuss the most convincing hypothesis explaining the mechanism by which an observed systemic occurrence may have repercussions in the brain.
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6
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Welcome MO, Mastorakis NE. Stress-induced blood brain barrier disruption: Molecular mechanisms and signaling pathways. Pharmacol Res 2020; 157:104769. [PMID: 32275963 DOI: 10.1016/j.phrs.2020.104769] [Citation(s) in RCA: 53] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/28/2019] [Revised: 03/09/2020] [Accepted: 03/19/2020] [Indexed: 02/07/2023]
Abstract
Stress is a nonspecific response to a threat or noxious stimuli with resultant damaging consequences. Stress is believed to be an underlying process that can trigger central nervous system disorders such as depression, anxiety, and post-traumatic stress disorder. Though the pathophysiological basis is not completely understood, data have consistently shown a pivotal role of inflammatory mediators and hypothalamo-pituitary-adrenal (HPA) axis activation in stress induced disorders. Indeed emerging experimental evidences indicate a concurrent activation of inflammatory signaling pathways and not only the HPA axis, but also, peripheral and central renin-angiotensin system (RAS). Furthermore, recent experimental data indicate that the HPA and RAS are coupled to the signaling of a range of central neuro-transmitter, -mediator and -peptide molecules that are also regulated, at least in part, by inflammatory signaling cascades and vice versa. More recently, experimental evidences suggest a critical role of stress in disruption of the blood brain barrier (BBB), a neurovascular unit that regulates the movement of substances and blood-borne immune cells into the brain parenchyma, and prevents peripheral injury to the brain substance. However, the mechanisms underlying stress-induced BBB disruption are not exactly known. In this review, we summarize studies conducted on the effects of stress on the BBB and integrate recent data that suggest possible molecular mechanisms and signaling pathways underlying stress-induced BBB disruption. Key molecular targets and pharmacological candidates for treatment of stress and related illnesses are also summarized.
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Affiliation(s)
- Menizibeya O Welcome
- Department of Physiology, Faculty of Basic Medical Sciences, College of Health Sciences, Nile University of Nigeria, Abuja, Nigeria.
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7
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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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8
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Tsai TY, Leong IL, Cheng KS, Shiao LR, Su TH, Wong KL, Chan P, Leung YM. Lysophosphatidylcholine-induced cytotoxicity and protection by heparin in mouse brain bEND.3 endothelial cells. Fundam Clin Pharmacol 2018; 33:52-62. [PMID: 29974515 DOI: 10.1111/fcp.12399] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2017] [Revised: 06/28/2018] [Accepted: 07/03/2018] [Indexed: 11/29/2022]
Affiliation(s)
- Tien-Yao Tsai
- Cardiovascular Division; Fu Jen Catholic University Hospital; New Taipei City Taiwan
- School of Medicine; College of Medicine; Fu Jen Catholic University; New Taipei City Taiwan
| | - Iat-Lon Leong
- Division of Cardiology; Department of Internal Medicine; Kiang Wu Hospital; Macau China
| | - Ka-Shun Cheng
- Department of Anesthesiology; China Medical University Hospital; Taichung Taiwan
- Department of Anesthesiology; The Qingdao University Yuhuangding Hospital; Yantai Shandong China
| | - Lian-Ru Shiao
- Department of Physiology; China Medical University; Taichung Taiwan
| | - Tzu-Hui Su
- Department of Anesthesiology; China Medical University Hospital; Taichung Taiwan
| | - Kar-Lok Wong
- Department of Anesthesiology; China Medical University Hospital; Taichung Taiwan
| | - Paul Chan
- Division of Cardiology; Department of Medicine; Taipei Medical University Wan Fang Hospital; Taipei Taiwan
| | - Yuk-Man Leung
- Department of Physiology; China Medical University; Taichung Taiwan
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9
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Li H, Cai J, Chen R, Zhao Z, Ying Z, Wang L, Chen J, Hao K, Kinney PL, Chen H, Kan H. Particulate Matter Exposure and Stress Hormone Levels. Circulation 2017; 136:618-627. [DOI: 10.1161/circulationaha.116.026796] [Citation(s) in RCA: 271] [Impact Index Per Article: 38.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/07/2016] [Accepted: 05/26/2017] [Indexed: 11/16/2022]
Abstract
Background:
Exposure to ambient particulate matter (PM) is associated with a number of adverse health outcomes, but potential mechanisms are largely unknown. Metabolomics represents a powerful approach to study global metabolic changes in response to environmental exposures. We therefore conducted this study to investigate changes in serum metabolites in response to the reduction of PM exposure among healthy college students.
Methods:
We conducted a randomized, double-blind crossover trial in 55 healthy college students in Shanghai, China. Real and sham air purifiers were placed in participants’ dormitories in random order for 9 days with a 12-day washout period. Serum metabolites were quantified by using gas chromatography-mass spectrometry and ultrahigh performance liquid chromatography-mass spectrometry. Between-treatment differences in metabolites were examined using orthogonal partial least square-discriminant analysis and mixed-effect models. Secondary outcomes include blood pressure, corticotropin-releasing hormone, adrenocorticotropic hormone, insulin resistance, and biomarkers of oxidative stress and inflammation.
Results:
The average personal exposure to PMs with aerodynamic diameters ≤2.5 μm was 24.3 μg/m
3
during the real purification and 53.1 μg/m
3
during the sham purification. Metabolomics analysis showed that higher exposure to PMs with aerodynamic diameters ≤2.5 μm led to significant increases in cortisol, cortisone, epinephrine, and norepinephrine. Between-treatment differences were also observed for glucose, amino acids, fatty acids, and lipids. We found significantly higher blood pressure, hormones, insulin resistance, and biomarkers of oxidative stress and inflammation among individuals exposed to higher PMs with aerodynamic diameters ≤2.5 μm.
Conclusions:
This study suggests that higher PM may induce metabolic alterations that are consistent with activations of the hypothalamus-pituitary-adrenal and sympathetic-adrenal-medullary axes, adding potential mechanistic insights into the adverse health outcomes associated with PM. Furthermore, our study demonstrated short-term reductions in stress hormone following indoor air purification.
Clinical Trial Registration:
URL:
http://www.clinicaltrials.gov
. Unique identifier: NCT02712333.
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Affiliation(s)
- Huichu Li
- From School of Public Health, Key Lab of Public Health Safety of the Ministry of Education and Key Lab of Health Technology Assessment of the Ministry of Health, Fudan University, Shanghai, China (H.L., J.C., R.C., Z.Z., Z.Y., H.K.); Shanghai Key Laboratory of Atmospheric Particle Pollution and Prevention (LAP3), Fudan University, China (J.C., R.C., Z.Y., L.W., J.C.); Department of Genetics and Genomics Sciences, Icahn School of Medicine at Mount Sinai, New York, NY (K.H.); The Icahn Institute for
| | - Jing Cai
- From School of Public Health, Key Lab of Public Health Safety of the Ministry of Education and Key Lab of Health Technology Assessment of the Ministry of Health, Fudan University, Shanghai, China (H.L., J.C., R.C., Z.Z., Z.Y., H.K.); Shanghai Key Laboratory of Atmospheric Particle Pollution and Prevention (LAP3), Fudan University, China (J.C., R.C., Z.Y., L.W., J.C.); Department of Genetics and Genomics Sciences, Icahn School of Medicine at Mount Sinai, New York, NY (K.H.); The Icahn Institute for
| | - Renjie Chen
- From School of Public Health, Key Lab of Public Health Safety of the Ministry of Education and Key Lab of Health Technology Assessment of the Ministry of Health, Fudan University, Shanghai, China (H.L., J.C., R.C., Z.Z., Z.Y., H.K.); Shanghai Key Laboratory of Atmospheric Particle Pollution and Prevention (LAP3), Fudan University, China (J.C., R.C., Z.Y., L.W., J.C.); Department of Genetics and Genomics Sciences, Icahn School of Medicine at Mount Sinai, New York, NY (K.H.); The Icahn Institute for
| | - Zhuohui Zhao
- From School of Public Health, Key Lab of Public Health Safety of the Ministry of Education and Key Lab of Health Technology Assessment of the Ministry of Health, Fudan University, Shanghai, China (H.L., J.C., R.C., Z.Z., Z.Y., H.K.); Shanghai Key Laboratory of Atmospheric Particle Pollution and Prevention (LAP3), Fudan University, China (J.C., R.C., Z.Y., L.W., J.C.); Department of Genetics and Genomics Sciences, Icahn School of Medicine at Mount Sinai, New York, NY (K.H.); The Icahn Institute for
| | - Zhekang Ying
- From School of Public Health, Key Lab of Public Health Safety of the Ministry of Education and Key Lab of Health Technology Assessment of the Ministry of Health, Fudan University, Shanghai, China (H.L., J.C., R.C., Z.Z., Z.Y., H.K.); Shanghai Key Laboratory of Atmospheric Particle Pollution and Prevention (LAP3), Fudan University, China (J.C., R.C., Z.Y., L.W., J.C.); Department of Genetics and Genomics Sciences, Icahn School of Medicine at Mount Sinai, New York, NY (K.H.); The Icahn Institute for
| | - Lin Wang
- From School of Public Health, Key Lab of Public Health Safety of the Ministry of Education and Key Lab of Health Technology Assessment of the Ministry of Health, Fudan University, Shanghai, China (H.L., J.C., R.C., Z.Z., Z.Y., H.K.); Shanghai Key Laboratory of Atmospheric Particle Pollution and Prevention (LAP3), Fudan University, China (J.C., R.C., Z.Y., L.W., J.C.); Department of Genetics and Genomics Sciences, Icahn School of Medicine at Mount Sinai, New York, NY (K.H.); The Icahn Institute for
| | - Jianmin Chen
- From School of Public Health, Key Lab of Public Health Safety of the Ministry of Education and Key Lab of Health Technology Assessment of the Ministry of Health, Fudan University, Shanghai, China (H.L., J.C., R.C., Z.Z., Z.Y., H.K.); Shanghai Key Laboratory of Atmospheric Particle Pollution and Prevention (LAP3), Fudan University, China (J.C., R.C., Z.Y., L.W., J.C.); Department of Genetics and Genomics Sciences, Icahn School of Medicine at Mount Sinai, New York, NY (K.H.); The Icahn Institute for
| | - Ke Hao
- From School of Public Health, Key Lab of Public Health Safety of the Ministry of Education and Key Lab of Health Technology Assessment of the Ministry of Health, Fudan University, Shanghai, China (H.L., J.C., R.C., Z.Z., Z.Y., H.K.); Shanghai Key Laboratory of Atmospheric Particle Pollution and Prevention (LAP3), Fudan University, China (J.C., R.C., Z.Y., L.W., J.C.); Department of Genetics and Genomics Sciences, Icahn School of Medicine at Mount Sinai, New York, NY (K.H.); The Icahn Institute for
| | - Patrick L. Kinney
- From School of Public Health, Key Lab of Public Health Safety of the Ministry of Education and Key Lab of Health Technology Assessment of the Ministry of Health, Fudan University, Shanghai, China (H.L., J.C., R.C., Z.Z., Z.Y., H.K.); Shanghai Key Laboratory of Atmospheric Particle Pollution and Prevention (LAP3), Fudan University, China (J.C., R.C., Z.Y., L.W., J.C.); Department of Genetics and Genomics Sciences, Icahn School of Medicine at Mount Sinai, New York, NY (K.H.); The Icahn Institute for
| | - Honglei Chen
- From School of Public Health, Key Lab of Public Health Safety of the Ministry of Education and Key Lab of Health Technology Assessment of the Ministry of Health, Fudan University, Shanghai, China (H.L., J.C., R.C., Z.Z., Z.Y., H.K.); Shanghai Key Laboratory of Atmospheric Particle Pollution and Prevention (LAP3), Fudan University, China (J.C., R.C., Z.Y., L.W., J.C.); Department of Genetics and Genomics Sciences, Icahn School of Medicine at Mount Sinai, New York, NY (K.H.); The Icahn Institute for
| | - Haidong Kan
- From School of Public Health, Key Lab of Public Health Safety of the Ministry of Education and Key Lab of Health Technology Assessment of the Ministry of Health, Fudan University, Shanghai, China (H.L., J.C., R.C., Z.Z., Z.Y., H.K.); Shanghai Key Laboratory of Atmospheric Particle Pollution and Prevention (LAP3), Fudan University, China (J.C., R.C., Z.Y., L.W., J.C.); Department of Genetics and Genomics Sciences, Icahn School of Medicine at Mount Sinai, New York, NY (K.H.); The Icahn Institute for
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Rajkumar P, Pluznick JL. Unsung renal receptors: orphan G-protein-coupled receptors play essential roles in renal development and homeostasis. Acta Physiol (Oxf) 2017; 220:189-200. [PMID: 27699982 DOI: 10.1111/apha.12813] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2016] [Revised: 09/23/2016] [Accepted: 09/29/2016] [Indexed: 12/31/2022]
Abstract
Recent studies have shown that orphan GPCRs of the GPR family are utilized as specialized chemosensors in various tissues to detect metabolites, and in turn to activate downstream pathways which regulate systemic homeostasis. These studies often find that such metabolites are generated by well-known metabolic pathways, implying that known metabolites and chemicals may perform novel functions. In this review, we summarize recent findings highlighting the role of deorphanized GPRs in renal development and function. Understanding the role of these receptors is critical in gaining insights into mechanisms that regulate renal function both in health and in disease.
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Affiliation(s)
- P. Rajkumar
- Department of Physiology; Johns Hopkins School of Medicine; Baltimore; MD USA
| | - J. L. Pluznick
- Department of Physiology; Johns Hopkins School of Medicine; Baltimore; MD USA
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11
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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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Ross T, Jakubzig B, Grundmann M, Massing U, Kostenis E, Schlesinger M, Bendas G. The molecular mechanism by which saturated lysophosphatidylcholine attenuates the metastatic capacity of melanoma cells. FEBS Open Bio 2016; 6:1297-1309. [PMID: 28255537 PMCID: PMC5324772 DOI: 10.1002/2211-5463.12152] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2016] [Revised: 10/13/2016] [Accepted: 10/25/2016] [Indexed: 12/11/2022] Open
Abstract
Lysophophatidylcholine (LysoPC) is an abundant constituent in human plasma. Patients with malignant cancer diseases have attenuated LysoPC plasma levels, and thus LysoPC has been examined as a metabolic biomarker for cancer prediction. Preclinical studies have shown that solid tumor cells drastically degrade LysoPCs by incorporating their free fatty acids into cell membrane phospholipids. In this way, LysoPC C18:0 reduced the metastatic spread of murine melanoma B16.F10 cells in mice. Although membrane rigidification may have a key role in the attenuation of metastasis, evidence for this has yet to be shown. Therefore, the present study aimed to determine how LysoPC reduces the metastatic capacity of B16.F10 cells. Following cellular preincubation with LysoPC C18:0 at increasing concentrations and lengths of time, cell migration was most significantly attenuated with 450 μm LysoPC C18:0 at 72 h. Biosensor measurements suggest that, despite their abundance in B16.F10 cells, LysoPC‐sensitive G protein‐coupled receptors do not appear to contribute to this effect. Instead, the attenuated migration appears to result from changes in cell membrane properties and their effect on underlying signaling pathways, most likely the formation of focal adhesion complexes. Treatment with 450 μm LysoPC C18:0 activates protein kinase C (PKC)δ to phosphorylate syndecan‐4, accompanied by deactivation of PKCα. Subsequently, focal adhesion complex formation was attenuated, as confirmed by the reduced activity of focal adhesion kinase (FAK). Interestingly, 450 μm LysoPC C18:1 did not affect FAK activity, explaining its lower propensity to affect migration and metastasis. Therefore, membrane rigidification by LysoPC C18:0 appears to prevent the formation of focal adhesion complexes, thus affecting integrin activity as a key for metastatic melanoma spread.
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Affiliation(s)
- Thomas Ross
- Department of Pharmaceutical Chemistry II University of Bonn Germany
| | - Bastian Jakubzig
- Department of Pharmaceutical Chemistry II University of Bonn Germany
| | | | - Ulrich Massing
- Andreas Hettich GmbH & Co. KGF&E Lifescience Applications Freiburg Germany; Faculty of Chemistry & Pharmacy University of Freiburg Germany
| | - Evi Kostenis
- Department of Pharmaceutical Biology University of Bonn Germany
| | | | - Gerd Bendas
- Department of Pharmaceutical Chemistry II University of Bonn Germany
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Maher-Edwards G, De'Ath J, Barnett C, Lavrov A, Lockhart A. A 24-week study to evaluate the effect of rilapladib on cognition and cerebrospinal fluid biomarkers of Alzheimer's disease. ALZHEIMERS & DEMENTIA-TRANSLATIONAL RESEARCH & CLINICAL INTERVENTIONS 2015; 1:131-140. [PMID: 29854933 PMCID: PMC5975052 DOI: 10.1016/j.trci.2015.06.003] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Background The lipoprotein-associated phospholipase A2 inhibitor (Lp-PLA2), rilapladib (SB659032), is being evaluated as a potential treatment to slow the progression of Alzheimer's disease (AD). Methods One hundred twenty-four subjects with possible mild AD and with neuroimaging evidence of cerebrovascular disease were randomized to placebo or 250-mg rilapladib once daily, for 24 weeks, in addition to stable background acetylcholinesterase inhibitor and/or memantine. The study assessed the safety and tolerability of rilapladib and its effects on cognition, mechanistic, and disease-related biomarkers. Although the overall intent behind the study was to take a broad exploratory view of the data, two primary end points of interest (cerebrospinal fluid [CSF] amyloid beta peptide 1–42 [Aβ1–42] and CogState executive function/working memory [EF/WM] composite score at week 24) were prespecified in the analysis plan for inferential statistical analysis. Results Rilapladib was well tolerated with no significant safety concerns. A significant difference from placebo was observed for rilapladib on change from baseline in EF/WM (effect size, 0.45; P = .026). There was no significant difference between groups on the change from baseline in CSF Aβ1–42 (P = .133). Preliminary evidence of effects was detected on other mechanistic (albumin quotient) and disease-related biomarkers (tau/P-tau and neurofilament light chain). Conclusion These data provide initial evidence supporting Lp-PLA2 inhibition as a novel treatment for dementia. Clinical Trial Registration Clinicaltrials.gov identifier: NCT01428453.
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Affiliation(s)
| | - Jeni De'Ath
- Neurosciences, GlaxoSmithKline, Uxbridge, Middlesex, UK
| | - Carly Barnett
- Neurosciences, GlaxoSmithKline, Uxbridge, Middlesex, UK
| | | | - Andrew Lockhart
- Neurosciences, GlaxoSmithKline, Clinical Unit Cambridge, Addenbrooke's Hospital, Cambridge, UK
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de Vallière C, Wang Y, Eloranta JJ, Vidal S, Clay I, Spalinger MR, Tcymbarevich I, Terhalle A, Ludwig MG, Suply T, Fried M, Kullak-Ublick GA, Frey-Wagner I, Scharl M, Seuwen K, Wagner CA, Rogler G. G Protein-coupled pH-sensing Receptor OGR1 Is a Regulator of Intestinal Inflammation. Inflamm Bowel Dis 2015; 21:1269-81. [PMID: 25856770 PMCID: PMC4450952 DOI: 10.1097/mib.0000000000000375] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/25/2014] [Accepted: 01/27/2015] [Indexed: 12/12/2022]
Abstract
BACKGROUND A novel family of proton-sensing G protein-coupled receptors, including OGR1, GPR4, and TDAG8, was identified to be important for physiological pH homeostasis and inflammation. Thus, we determined the function of proton-sensing OGR1 in the intestinal mucosa. MTEHODS OGR1 expression in colonic tissues was investigated in controls and patients with IBD. Expression of OGR1 upon cell activation was studied in the Mono Mac 6 (MM6) cell line and primary human and murine monocytes by real-time PCR. Ogr1 knockout mice were crossbred with Il-10 deficient mice and studied for more than 200 days. Microarray profiling was performed using Ogr1 and Ogr1 (WT) residential peritoneal macrophages. RESULTS Patients with IBD expressed higher levels of OGR1 in the mucosa than non-IBD controls. Treatment of MM6 cells with TNF, led to significant upregulation of OGR1 expression, which could be reversed by the presence of NF-κB inhibitors. Kaplan-Meier survival analysis showed a significantly delayed onset and progression of rectal prolapse in female Ogr1/Il-10 mice. These mice displayed significantly less rectal prolapses. Upregulation of gene expression, mediated by OGR1, in response to extracellular acidification in mouse macrophages was enriched for inflammation and immune response, actin cytoskeleton, and cell-adhesion gene pathways. CONCLUSIONS OGR1 expression is induced in cells of human macrophage lineage and primary human monocytes by TNF. NF-κB inhibition reverses the induction of OGR1 expression by TNF. OGR1 deficiency protects from spontaneous inflammation in the Il-10 knockout model. Our data indicate a pathophysiological role for pH-sensing receptor OGR1 during the pathogenesis of mucosal inflammation.
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Affiliation(s)
- Cheryl de Vallière
- Division of Gastroenterology and Hepatology, University Hospital Zürich, Zürich, Switzerland
| | - Yu Wang
- Division of Gastroenterology and Hepatology, University Hospital Zürich, Zürich, Switzerland
- Institute of Physiology, University of Zürich, Zürich, Switzerland
| | - Jyrki J. Eloranta
- Department of Clinical Pharmacology and Toxicology, University Hospital Zürich, Zürich, Switzerland; and
| | - Solange Vidal
- Novartis Institutes for Biomedical Research, Basel, Switzerland
| | - Ieuan Clay
- Novartis Institutes for Biomedical Research, Basel, Switzerland
| | - Marianne R. Spalinger
- Division of Gastroenterology and Hepatology, University Hospital Zürich, Zürich, Switzerland
| | - Irina Tcymbarevich
- Division of Gastroenterology and Hepatology, University Hospital Zürich, Zürich, Switzerland
| | - Anne Terhalle
- Division of Gastroenterology and Hepatology, University Hospital Zürich, Zürich, Switzerland
| | | | - Thomas Suply
- Novartis Institutes for Biomedical Research, Basel, Switzerland
| | - Michael Fried
- Division of Gastroenterology and Hepatology, University Hospital Zürich, Zürich, Switzerland
| | - Gerd A. Kullak-Ublick
- Department of Clinical Pharmacology and Toxicology, University Hospital Zürich, Zürich, Switzerland; and
| | - Isabelle Frey-Wagner
- Division of Gastroenterology and Hepatology, University Hospital Zürich, Zürich, Switzerland
| | - Michael Scharl
- Division of Gastroenterology and Hepatology, University Hospital Zürich, Zürich, Switzerland
| | - Klaus Seuwen
- Novartis Institutes for Biomedical Research, Basel, Switzerland
| | | | - Gerhard Rogler
- Division of Gastroenterology and Hepatology, University Hospital Zürich, Zürich, Switzerland
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15
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Gazos-Lopes F, Oliveira MM, Hoelz LVB, Vieira DP, Marques AF, Nakayasu ES, Gomes MT, Salloum NG, Pascutti PG, Souto-Padrón T, Monteiro RQ, Lopes AH, Almeida IC. Structural and functional analysis of a platelet-activating lysophosphatidylcholine of Trypanosoma cruzi. PLoS Negl Trop Dis 2014; 8:e3077. [PMID: 25101628 PMCID: PMC4125143 DOI: 10.1371/journal.pntd.0003077] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2013] [Accepted: 06/13/2014] [Indexed: 12/15/2022] Open
Abstract
Background Trypanosoma cruzi is the causative agent of the life-threatening Chagas disease, in which increased platelet aggregation related to myocarditis is observed. Platelet-activating factor (PAF) is a potent intercellular lipid mediator and second messenger that exerts its activity through a PAF-specific receptor (PAFR). Previous data from our group suggested that T. cruzi synthesizes a phospholipid with PAF-like activity. The structure of T. cruzi PAF-like molecule, however, remains elusive. Methodology/Principal findings Here, we have purified and structurally characterized the putative T. cruzi PAF-like molecule by electrospray ionization-tandem mass spectrometry (ESI-MS/MS). Our ESI-MS/MS data demonstrated that the T. cruzi PAF-like molecule is actually a lysophosphatidylcholine (LPC), namely sn-1 C18:1(delta 9)-LPC. Similar to PAF, the platelet-aggregating activity of C18:1-LPC was abrogated by the PAFR antagonist, WEB 2086. Other major LPC species, i.e., C16:0-, C18:0-, and C18:2-LPC, were also characterized in all T. cruzi stages. These LPC species, however, failed to induce platelet aggregation. Quantification of T. cruzi LPC species by ESI-MS revealed that intracellular amastigote and trypomastigote forms have much higher levels of C18:1-LPC than epimastigote and metacyclic trypomastigote forms. C18:1-LPC was also found to be secreted by the parasite in extracellular vesicles (EV) and an EV-free fraction. A three-dimensional model of PAFR was constructed and a molecular docking study was performed to predict the interactions between the PAFR model and PAF, and each LPC species. Molecular docking data suggested that, contrary to other LPC species analyzed, C18:1-LPC is predicted to interact with the PAFR model in a fashion similar to PAF. Conclusions/Significance Taken together, our data indicate that T. cruzi synthesizes a bioactive C18:1-LPC, which aggregates platelets via PAFR. We propose that C18:1-LPC might be an important lipid mediator in the progression of Chagas disease and its biosynthesis could eventually be exploited as a potential target for new therapeutic interventions. Chagas disease, caused by the parasite Trypanosoma cruzi, was exclusively confined to Latin America but it has recently spread to other regions of the world. Chagas disease affects 8–10 million people and kills thousands of them every year. Lysophosphatidylcholine (LPC) is a major bioactive phospholipid of human plasma low-density lipoproteins (LDL). Platelet-activating factor (PAF) is a phospholipid similar to LPC and a potent intercellular mediator. Both PAF and LPC have been reported to act on mammalian cells through PAF receptor (PAFR). Previous data from our group suggested that T. cruzi produces a phospholipid with PAF activity. Here, we describe the structural and functional analysis of different species of LPC from T. cruzi, including a LPC with a fatty acid chain of 18 carbon atoms and one double bond (C18:1-LPC). We also show that C18:1-LPC is able to induce rabbit platelet aggregation, which is abrogated by a PAFR antagonist. In addition, a three-dimensional model of human PAFR was constructed. Contrary to other T. cruzi LPC molecules, C18:1-LPC is predicted to interact with the PAFR model in a fashion similar to PAF. Further studies are needed to validate the biosynthesis of T. cruzi C18:1-LPC as a potential drug target in Chagas disease.
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Affiliation(s)
- Felipe Gazos-Lopes
- The Border Biomedical Research Center, Department of Biological Sciences, University of Texas at El Paso (UTEP), El Paso, Texas, United States of America
| | - Mauricio M. Oliveira
- Instituto de Microbiologia Paulo de Góes, Universidade Federal do Rio de Janeiro, Cidade Universitária, Centro de Ciências da Saúde, Bloco I, Ilha do Fundão, Rio de Janeiro, Rio de Janeiro, Brazil
| | - Lucas V. B. Hoelz
- Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Cidade Universitária, Centro de Ciências da Saúde, Bloco G, Ilha do Fundão, Rio de Janeiro, Rio de Janeiro, Brazil
| | - Danielle P. Vieira
- Instituto de Microbiologia Paulo de Góes, Universidade Federal do Rio de Janeiro, Cidade Universitária, Centro de Ciências da Saúde, Bloco I, Ilha do Fundão, Rio de Janeiro, Rio de Janeiro, Brazil
| | - Alexandre F. Marques
- The Border Biomedical Research Center, Department of Biological Sciences, University of Texas at El Paso (UTEP), El Paso, Texas, United States of America
- Universidade Federal de Minas Gerais, Instituto de Ciências Biológicas, Departamento de Parasitologia, Pampulha, Belo Horizonte, Minas Gerais, Brazil
| | - Ernesto S. Nakayasu
- The Border Biomedical Research Center, Department of Biological Sciences, University of Texas at El Paso (UTEP), El Paso, Texas, United States of America
| | - Marta T. Gomes
- Instituto de Microbiologia Paulo de Góes, Universidade Federal do Rio de Janeiro, Cidade Universitária, Centro de Ciências da Saúde, Bloco I, Ilha do Fundão, Rio de Janeiro, Rio de Janeiro, Brazil
- Instituto de Bioquímica Médica, Universidade Federal do Rio de Janeiro, Cidade Universitária, Centro de Ciências da Saúde, Bloco H, Ilha do Fundão, Rio de Janeiro, Rio de Janeiro, Brazil
| | - Nasim G. Salloum
- The Border Biomedical Research Center, Department of Biological Sciences, University of Texas at El Paso (UTEP), El Paso, Texas, United States of America
| | - Pedro G. Pascutti
- Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Cidade Universitária, Centro de Ciências da Saúde, Bloco G, Ilha do Fundão, Rio de Janeiro, Rio de Janeiro, Brazil
| | - Thaïs Souto-Padrón
- Instituto de Microbiologia Paulo de Góes, Universidade Federal do Rio de Janeiro, Cidade Universitária, Centro de Ciências da Saúde, Bloco I, Ilha do Fundão, Rio de Janeiro, Rio de Janeiro, Brazil
| | - Robson Q. Monteiro
- Instituto de Bioquímica Médica, Universidade Federal do Rio de Janeiro, Cidade Universitária, Centro de Ciências da Saúde, Bloco H, Ilha do Fundão, Rio de Janeiro, Rio de Janeiro, Brazil
| | - Angela H. Lopes
- Instituto de Microbiologia Paulo de Góes, Universidade Federal do Rio de Janeiro, Cidade Universitária, Centro de Ciências da Saúde, Bloco I, Ilha do Fundão, Rio de Janeiro, Rio de Janeiro, Brazil
- * E-mail: (AHL); (ICA)
| | - Igor C. Almeida
- The Border Biomedical Research Center, Department of Biological Sciences, University of Texas at El Paso (UTEP), El Paso, Texas, United States of America
- * E-mail: (AHL); (ICA)
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Dong L, Li Z, Leffler NR, Asch AS, Chi JT, Yang LV. Acidosis activation of the proton-sensing GPR4 receptor stimulates vascular endothelial cell inflammatory responses revealed by transcriptome analysis. PLoS One 2013; 8:e61991. [PMID: 23613998 PMCID: PMC3628782 DOI: 10.1371/journal.pone.0061991] [Citation(s) in RCA: 112] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2012] [Accepted: 03/18/2013] [Indexed: 12/13/2022] Open
Abstract
Acidic tissue microenvironment commonly exists in inflammatory diseases, tumors, ischemic organs, sickle cell disease, and many other pathological conditions due to hypoxia, glycolytic cell metabolism and deficient blood perfusion. However, the molecular mechanisms by which cells sense and respond to the acidic microenvironment are not well understood. GPR4 is a proton-sensing receptor expressed in endothelial cells and other cell types. The receptor is fully activated by acidic extracellular pH but exhibits lesser activity at the physiological pH 7.4 and minimal activity at more alkaline pH. To delineate the function and signaling pathways of GPR4 activation by acidosis in endothelial cells, we compared the global gene expression of the acidosis response in primary human umbilical vein endothelial cells (HUVEC) with varying level of GPR4. The results demonstrated that acidosis activation of GPR4 in HUVEC substantially increased the expression of a number of inflammatory genes such as chemokines, cytokines, adhesion molecules, NF-κB pathway genes, and prostaglandin-endoperoxidase synthase 2 (PTGS2 or COX-2) and stress response genes such as ATF3 and DDIT3 (CHOP). Similar GPR4-mediated acidosis induction of the inflammatory genes was also noted in other types of endothelial cells including human lung microvascular endothelial cells and pulmonary artery endothelial cells. Further analyses indicated that the NF-κB pathway was important for the acidosis/GPR4-induced inflammatory gene expression. Moreover, acidosis activation of GPR4 increased the adhesion of HUVEC to U937 monocytic cells under a flow condition. Importantly, treatment with a recently identified GPR4 antagonist significantly reduced the acidosis/GPR4-mediated endothelial cell inflammatory response. Taken together, these results show that activation of GPR4 by acidosis stimulates the expression of a wide range of inflammatory genes in endothelial cells. Such inflammatory response can be suppressed by GPR4 small molecule inhibitors and hold potential therapeutic value.
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Affiliation(s)
- Lixue Dong
- Department of Oncology, Brody School of Medicine, East Carolina University, Greenville, North Carolina, United States of America
- Department of Internal Medicine, Brody School of Medicine, East Carolina University, Greenville, North Carolina, United States of America
| | - Zhigang Li
- Department of Oncology, Brody School of Medicine, East Carolina University, Greenville, North Carolina, United States of America
- Department of Internal Medicine, Brody School of Medicine, East Carolina University, Greenville, North Carolina, United States of America
| | - Nancy R. Leffler
- Department of Oncology, Brody School of Medicine, East Carolina University, Greenville, North Carolina, United States of America
- Department of Internal Medicine, Brody School of Medicine, East Carolina University, Greenville, North Carolina, United States of America
| | - Adam S. Asch
- Department of Oncology, Brody School of Medicine, East Carolina University, Greenville, North Carolina, United States of America
- Department of Internal Medicine, Brody School of Medicine, East Carolina University, Greenville, North Carolina, United States of America
- UNC Lineberger Comprehensive Cancer Center, Chapel Hill, North Carolina, United States of America
| | - Jen-Tsan Chi
- Institute for Genome Sciences and Policy, Duke University, Durham, North Carolina, United States of America
- Department of Molecular Genetics and Microbiology, Duke University, Durham, North Carolina, United States of America
| | - Li V. Yang
- Department of Oncology, Brody School of Medicine, East Carolina University, Greenville, North Carolina, United States of America
- Department of Internal Medicine, Brody School of Medicine, East Carolina University, Greenville, North Carolina, United States of America
- Department of Anatomy and Cell Biology, Brody School of Medicine, East Carolina University, Greenville, North Carolina, United States of America
- UNC Lineberger Comprehensive Cancer Center, Chapel Hill, North Carolina, United States of America
- * E-mail:
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Grzelczyk A, Gendaszewska-Darmach E. Novel bioactive glycerol-based lysophospholipids: new data -- new insight into their function. Biochimie 2012; 95:667-79. [PMID: 23089136 DOI: 10.1016/j.biochi.2012.10.009] [Citation(s) in RCA: 115] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2012] [Accepted: 10/11/2012] [Indexed: 11/28/2022]
Abstract
Based on the results of research conducted over last two decades, lysophospholipids (LPLs) were observed to be not only structural components of cellular membranes but also biologically active molecules influencing a broad variety of processes such as carcinogenesis, neurogenesis, immunity, vascular development or regulation of metabolic diseases. With a growing interest in the involvement of extracellular lysophospholipids in both normal physiology and pathology, it has become evident that those small molecules may have therapeutic potential. While lysophosphatidic acid (LPA) and sphingosine-1-phosphate (S1P) have been studied in detail, other LPLs such as lysophosphatidylglycerol (LPG), lysophosphatidylserine (LPS), lysophosphatidylinositol (LPI), lysophosphatidylethanolamine (LPE) or even lysophosphatidylcholine (LPC) have not been elucidated to such a high degree. Although information concerning the latter LPLs is sparse as compared to LPA and S1P, within the last couple of years much progress has been made. Recently published data suggest that these compounds may regulate fundamental cellular activities by modulating multiple molecular targets, e.g. by binding to specific receptors and/or altering the structure and fluidity of lipid rafts. Therefore, the present review is devoted to novel bioactive glycerol-based lysophospholipids and recent findings concerning their functions and possible signaling pathways regulating physiological and pathological processes.
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Affiliation(s)
- Anna Grzelczyk
- Institute of Technical Biochemistry, Faculty of Biotechnology and Food Sciences, Lodz University of Technology, Stefanowskiego 4/10, 90-924 Lodz, Poland
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Zhou L, Ding L, Yin P, Lu X, Wang X, Niu J, Gao P, Xu G. Serum metabolic profiling study of hepatocellular carcinoma infected with hepatitis B or hepatitis C virus by using liquid chromatography-mass spectrometry. J Proteome Res 2012; 11:5433-42. [PMID: 22946841 DOI: 10.1021/pr300683a] [Citation(s) in RCA: 66] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
The objective of the present study was to explore the common and specific metabolic alterations of hepatocellular carcinoma (HCC) infected with hepatitis B virus (HBV) or hepatitis C virus (HCV). Serum profiling data revealed that the two HCC groups shared a mainly similar metabolic profile, providing a basis for investigating their common tumor pathogenesis mechanism and early diagnosis biomarkers. Arachidonic acid as a pro-inflammatory precursor increased significantly in the HCC group compared to the cirrhosis and healthy control. And the lysophosphatidylcholines (lysoPCs) with polyunsaturated fatty acid acyl chain with potent anti-inflammatory activity significantly decreased in the HCC and cirrhosis groups compared to those in the healthy control group, which may partly contribute to maintaining chronic inflammation and benefit the initiation and progression of the malignant hepatic tumor. The decreased ratios of polyunsaturated lysoPCs to saturated lysoPCs in HCC groups compared to chronic liver diseases infected with HBV or HCV and healthy control further demonstrated that a malignant liver tumor exerts profound influences independent of virus infection. Especially, serum endocannabinoids anandamide (AEA) and palmitylethanolamide (PEA) were found significantly elevated in HCC groups compared to healthy control, and in HCC with HCV compared to corresponding chronic liver diseases. AEA, PEA, or their combination showed better sensitivity, specificity, and the area under the curve for distinguishing HCC from chronic liver diseases, showing they are potential biomarkers to distinguish the HCC from cirrhosis infected with HCV.
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Affiliation(s)
- Lina Zhou
- CAS Key Laboratory of Separation Science for Analytical Chemistry, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian, 116023, China
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Jancic CC, Cabrini M, Gabelloni ML, Rodríguez Rodrigues C, Salamone G, Trevani AS, Geffner J. Low extracellular pH stimulates the production of IL-1β by human monocytes. Cytokine 2011; 57:258-68. [PMID: 22154780 DOI: 10.1016/j.cyto.2011.11.013] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2011] [Revised: 10/06/2011] [Accepted: 11/17/2011] [Indexed: 10/14/2022]
Abstract
The development of acidic environments is a hallmark of inflammatory processes of different etiology. We have previously shown that transient exposure to acidic conditions, similar to those encountered in vivo, induces the activation of neutrophils and the phenotypic maturation of dendritic cells. We here report that extracellular acidosis (pH 6.5) selectively stimulates the production and the secretion of IL-1β by human monocytes without affecting the production of TNF-α, IL-6 and the expression of CD40, CD80, CD86, and HLA-DR. Stimulation of IL-1β production by pH 6.5-treated monocytes was shown to be dependent on caspase-1 activity, and it was also observed using peripheral blood mononuclear cells instead of isolated monocytes. Contrasting with the results in monocytes, we found that pH 6.5 did not stimulate any production of IL-1β by macrophages. Changes in intracellular pH seem to be involved in the stimulation of IL-1β production. In fact, monocytes cultured at pH 6.5 undergo a fall in the values of intracellular pH while the inhibitor of the Na+/H+ exchanger, 5-(N-ethyl-N-isopropyl)amiloride induced both, a decrease in the values of intracellular pH and the stimulation of IL-1β production. Real time quantitative PCR assays indicated that monocytes cultured either at pH 6.5 or in the presence of 5-(N-ethyl-N-isopropyl)amiloride expressed higher levels of pro-IL-1β mRNA suggesting that low values of intracellular pH enhance the production of IL-1β, at least in part, by stimulating the synthesis of its precursor.
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Affiliation(s)
- Carolina Cristina Jancic
- Instituto de Investigaciones Hematológicas (IIHEMA), Academia Nacional de Medicina, Buenos Aires, Argentina.
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20
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Chen A, Dong L, Leffler NR, Asch AS, Witte ON, Yang LV. Activation of GPR4 by acidosis increases endothelial cell adhesion through the cAMP/Epac pathway. PLoS One 2011; 6:e27586. [PMID: 22110680 PMCID: PMC3217975 DOI: 10.1371/journal.pone.0027586] [Citation(s) in RCA: 100] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2011] [Accepted: 10/20/2011] [Indexed: 01/11/2023] Open
Abstract
Endothelium-leukocyte interaction is critical for inflammatory responses. Whereas the tissue microenvironments are often acidic at inflammatory sites, the mechanisms by which cells respond to acidosis are not well understood. Using molecular, cellular and biochemical approaches, we demonstrate that activation of GPR4, a proton-sensing G protein-coupled receptor, by isocapnic acidosis increases the adhesiveness of human umbilical vein endothelial cells (HUVECs) that express GPR4 endogenously. Acidosis in combination with GPR4 overexpression further augments HUVEC adhesion with U937 monocytes. In contrast, overexpression of a G protein signaling-defective DRY motif mutant (R115A) of GPR4 does not elicit any increase of HUVEC adhesion, indicating the requirement of G protein signaling. Downregulation of GPR4 expression by RNA interference reduces the acidosis-induced HUVEC adhesion. To delineate downstream pathways, we show that inhibition of adenylate cyclase by inhibitors, 2',5'-dideoxyadenosine (DDA) or SQ 22536, attenuates acidosis/GPR4-induced HUVEC adhesion. Consistently, treatment with a cAMP analog or a G(i) signaling inhibitor increases HUVEC adhesiveness, suggesting a role of the G(s)/cAMP signaling in this process. We further show that the cAMP downstream effector Epac is important for acidosis/GPR4-induced cell adhesion. Moreover, activation of GPR4 by acidosis increases the expression of vascular adhesion molecules E-selectin, VCAM-1 and ICAM-1, which are functionally involved in acidosis/GPR4-mediated HUVEC adhesion. Similarly, hypercapnic acidosis can also activate GPR4 to stimulate HUVEC adhesion molecule expression and adhesiveness. These results suggest that acidosis/GPR4 signaling regulates endothelial cell adhesion mainly through the G(s)/cAMP/Epac pathway and may play a role in the inflammatory response of vascular endothelial cells.
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Affiliation(s)
- Aishe Chen
- Department of Internal Medicine, Brody School of Medicine, East Carolina University, Greenville, North Carolina, United States of America
| | - Lixue Dong
- Department of Internal Medicine, Brody School of Medicine, East Carolina University, Greenville, North Carolina, United States of America
| | - Nancy R. Leffler
- Department of Internal Medicine, Brody School of Medicine, East Carolina University, Greenville, North Carolina, United States of America
| | - Adam S. Asch
- Department of Internal Medicine, Brody School of Medicine, East Carolina University, Greenville, North Carolina, United States of America
- UNC Lineberger Comprehensive Cancer Center, Chapel Hill, North Carolina, United States of America
| | - Owen N. Witte
- Howard Hughes Medical Institute, University of California Los Angeles, Los Angeles, California, United States of America
| | - Li V. Yang
- Department of Internal Medicine, Brody School of Medicine, East Carolina University, Greenville, North Carolina, United States of America
- Department of Anatomy and Cell Biology, Brody School of Medicine, East Carolina University, Greenville, North Carolina, United States of America
- UNC Lineberger Comprehensive Cancer Center, Chapel Hill, North Carolina, United States of America
- * E-mail:
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21
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Reduced pathological angiogenesis and tumor growth in mice lacking GPR4, a proton sensing receptor. Angiogenesis 2011; 14:533-44. [PMID: 22045552 DOI: 10.1007/s10456-011-9238-9] [Citation(s) in RCA: 58] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2011] [Accepted: 10/11/2011] [Indexed: 10/16/2022]
Abstract
The G protein-coupled receptor GPR4 is activated by acidic pH and recent evidence indicates that it is expressed in endothelial cells. In agreement with these reports, we observe a high correlation of GPR4 mRNA expression with endothelial marker genes, and we confirm expression and acidic pH dependent function of GPR4 in primary human vascular endothelial cells. GPR4-deficient mice were generated; these are viable and fertile and show no gross abnormalities. However, these animals show a significantly reduced angiogenic response to VEGF (vascular endothelial growth factor), but not to bFGF (basic fibroblast growth factor), in a growth factor implant model. Accordingly, in two different orthotopic models, tumor growth is strongly reduced in mice lacking GPR4. Histological analysis of tumors indicates reduced tumor cell proliferation as well as altered vessel morphology, length and density. Moreover, GPR4 deficiency results in reduced VEGFR2 (VEGF Receptor 2) levels in endothelial cells, accounting, at least in part, for the observed phenotype. Our data suggest that endothelial cells sense local tissue acidosis via GPR4 and that this signal is required to generate a full angiogenic response to VEGF.
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22
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Rao G, Ding HG, Huang W, Le D, Maxhimer JB, Oosterhof A, van Kuppevelt T, Lum H, Lewis EJ, Reddy V, Prinz RA, Xu X. Reactive oxygen species mediate high glucose-induced heparanase-1 production and heparan sulphate proteoglycan degradation in human and rat endothelial cells: a potential role in the pathogenesis of atherosclerosis. Diabetologia 2011; 54:1527-38. [PMID: 21424539 DOI: 10.1007/s00125-011-2110-z] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/22/2010] [Accepted: 02/01/2011] [Indexed: 01/10/2023]
Abstract
AIMS/HYPOTHESIS The content of heparan sulphate is reduced in the endothelium under hyperglycaemic conditions and may contribute to the pathogenesis of atherosclerosis. Heparanase-1 (HPR1) specifically degrades heparan sulphate proteoglycans. We therefore sought to determine whether: (1) heparan sulphate reduction in endothelial cells is due to increased HPR1 production through increased reactive oxygen species (ROS) production; and (2) HPR1 production is increased in vivo in endothelial cells under hyperglycaemic and/or atherosclerotic conditions. METHODS HPR1 mRNA and protein levels in endothelial cells were analysed by RT-PCR and Western blot or HPR1 enzymatic activity assay, respectively. Cell surface heparan sulphate levels were analysed by FACS. HPR1 in the artery from control rats and a rat model of diabetes, and from patients under hyperglycaemic and/or atherosclerotic conditions was immunohistochemically examined. RESULTS High-glucose-induced HPR1 production and heparan sulphate degradation in three human endothelial cell lines, both of which were blocked by ROS scavengers, glutathione and N-acetylcysteine. Exogenous H(2)O(2) induced HPR1 production, subsequently leading to decreased cell surface heparan sulphate levels. HPR1 content was significantly increased in endothelial cells in the arterial walls of a rat model of diabetes. Clinical studies revealed that HPR1 production was increased in endothelial cells under hyperglycaemic conditions, and in endothelial cells and macrophages in atherosclerotic lesions. CONCLUSIONS/INTERPRETATION Hyperglycaemia induces HPR1 production and heparan sulphate degradation in endothelial cells through ROS. HPR1 production is increased in endothelial cells from a rat model of diabetes, and in macrophages in the atherosclerotic lesions of diabetic and non-diabetic patients. Increased HPR1 production may contribute to the pathogenesis and progression of atherosclerosis.
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Affiliation(s)
- G Rao
- Department of General Surgery, Rush University Medical Center, 1653 W Congress Parkway, Chicago, IL 60612, USA
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23
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Tomura H, Mogi C, Sato K, Okajima F. [Proton-sensing G-protein-coupled receptors and their physiological roles]. Nihon Yakurigaku Zasshi 2010; 135:240-4. [PMID: 20543514 DOI: 10.1254/fpj.135.240] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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24
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Riederer M, Ojala PJ, Hrzenjak A, Graier WF, Malli R, Tritscher M, Hermansson M, Watzer B, Schweer H, Desoye G, Heinemann A, Frank S. Acyl chain-dependent effect of lysophosphatidylcholine on endothelial prostacyclin production. J Lipid Res 2010; 51:2957-66. [PMID: 20610733 DOI: 10.1194/jlr.m006536] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Previously we identified palmitoyl-lysophosphatidylcholine (16:0 LPC), linoleoyl-LPC (18:2 LPC), arachidonoyl-LPC (20:4 LPC), and oleoyl-LPC (18:1 LPC) as the most prominent LPC species generated by the action of endothelial lipase (EL) on high-density lipoprotein. In the present study, the impact of those LPC on prostacyclin (PGI(2)) production was examined in vitro in primary human aortic endothelial cells (HAEC) and in vivo in mice. Although 18:2 LPC was inactive, 16:0, 18:1, and 20:4 LPC induced PGI(2) production in HAEC by 1.4-, 3-, and 8.3-fold, respectively. LPC-elicited 6-keto PGF1α formation depended on both cyclooxygenase (COX)-1 and COX-2 and on the activity of cytosolic phospholipase type IVA (cPLA2). The LPC-induced, cPLA2-dependent (14)C-arachidonic acid (AA) release was increased 4.5-fold with 16:0, 2-fold with 18:1, and 2.7-fold with 20:4 LPC, respectively, and related to the ability of LPC to increase cytosolic Ca(2+) concentration. In vivo, LPC increased 6-keto PGF(1α) concentration in mouse plasma with a similar order of potency as found in HAEC. Our results indicate that the tested LPC species are capable of eliciting production of PGI(2), whereby the efficacy and the relative contribution of underlying mechanisms are strongly related to acyl-chain length and degree of saturation.
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Affiliation(s)
- Monika Riederer
- Institute of Molecular Biology and Biochemistry, University of Helsinki, Helsinki, Finland
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25
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Fu P, Birukov KG. Oxidized phospholipids in control of inflammation and endothelial barrier. Transl Res 2009; 153:166-76. [PMID: 19304275 PMCID: PMC3677584 DOI: 10.1016/j.trsl.2008.12.005] [Citation(s) in RCA: 60] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/03/2008] [Revised: 12/15/2008] [Accepted: 12/16/2008] [Indexed: 11/17/2022]
Abstract
The levels of circulating oxidized phospholipids (OxPLs) become increased in chronic and acute pathologic conditions such as hyperlipidemia, atherosclerosis, increased intimamedia thickness in the patients with systemic Lupus erythematosus, vascular balloon injury, acute lung injury (ALI), and acute respiratory distress syndrome (ARDS). These pathologies are associated with inflammation and activation of endothelial cells. Depending on the biological context and the specific group of phospholipid oxidation products, OxPL may exhibit both proinflammatory and anti-inflammatory effects. This review will summarize the data showing a dual role of OxPL in modulation of chronic and acute inflammation as well as OxPL effects on pulmonary endothelial permeability. Recent reports show protective effects of OxPL in the models of endotoxin and ventilator-induced ALI and suggest a potential for using OxPL-derived cyclopenthenone-containing compounds with barrier-protective properties for drug design. These compounds may represent a new group of therapeutic agents for the treatment of lung syndromes associated with acute inflammation and lung vascular leak.
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Key Words
- ali, acute lung injury
- camp, cyclic adenosine monophosphate
- cox-2, cyclooxygenase-2
- cs1, connecting segment 1
- ec, endothelial cell
- enos, endothelial nitric oxide synthase
- erk1/2, extracellular signaling kinase 1/2
- egr-1, early growth response factor-1
- fak, focal adhesion kinase
- gas, gamma-interferon activation sequence
- gpcr, g-protein-coupled receptor
- gpi, glycosylphosphatidylinositol
- gtp, guanosine triphosphate
- ho-1, heme oxygenase-1
- icam-1, intercellular adhesion molecule-1, il-8, interleukin-8
- kodia-pc, 5-keto-6-octendioic acid ester of 2-lyso-phosphocholine
- lbp, lps binding protein
- ldl, low-density lipoprotein
- l-name, n-nitro-l-arginine-methyl ester
- lps, lipopolysaccharide
- mcp1, monocyte chemotactic protein 1
- mlc, myosin light chain
- mm-ldl, minimally modified ldl
- mrna, messenger rna
- nfκb, nuclear factor κb
- oxldl, oxidated ldl
- oxpapc, oxidized 1-palmitoyl-2-arachidonoyl-sn-glycero-3-phosphorylcholine
- oxpl, oxidized phospholipids
- paf, platelet activation factor
- papc, 1-palmitoyl-2-arachidonoyl-sn-glycero-3-phosphorylcholine
- pape, 1-palmitoyl-2-arachidonoyl-sn-glycero-3-phosphatidylethanolamine
- paps, 1-palmitoyl-2-arachidonoyl-sn-glycero-3-phosphatidylserine
- pecpc, 1-palmitoyl-2-(5,6-epoxycyclopentenone)-sn-glycero-3-phsphocholine
- peipc, 1-palmitoyl-2-(5,6-epoxyisoprostane e2)-sn-glycero-3-phsphocholine
- pge2, prostaglandin e2
- pgpc, 1-palmitoyl-2-glutaroyl-sn-glycero-phosphocholine
- pka, protein kinase a
- pkc, protein kinase c
- pla2, phospholipase a2
- povpc, 1-palmitoyl-2-(5-oxovaleroyl)-sn-glycero-phosphocholine
- ppar, peroxisome proliferator-activated receptor
- ros, reactive oxygen species
- sirna, small interfering rna
- srebp, sterol response element binding protein
- tf, tissue factor
- tlr, toll-like receptor
- tnf-α, tumor necrosis factor-α
- upr, unfolded protein response
- vcam-1, vascular cell adhesion molecule-1
- vegf, vascular endothelial growth factor
- vili, ventilator-induced lung injury
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Affiliation(s)
- Panfeng Fu
- Section of Pulmonary and Critical Care Medicine, Department of Medicine, University of Chicago, Chicago, Ill 60637, USA
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Chen C, Shah YM, Morimura K, Krausz KW, Miyazaki M, Richardson TA, Morgan ET, Ntambi JM, Idle JR, Gonzalez FJ. Metabolomics reveals that hepatic stearoyl-CoA desaturase 1 downregulation exacerbates inflammation and acute colitis. Cell Metab 2008; 7:135-47. [PMID: 18249173 PMCID: PMC2276699 DOI: 10.1016/j.cmet.2007.12.003] [Citation(s) in RCA: 126] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/04/2007] [Revised: 10/23/2007] [Accepted: 12/14/2007] [Indexed: 02/08/2023]
Abstract
To investigate the pathogenic mechanism of ulcerative colitis, a dextran sulfate sodium (DSS)-induced acute colitis model was examined by serum metabolomic analysis. Higher levels of stearoyl lysophosphatidylcholine and lower levels of oleoyl lysophosphatidylcholine in DSS-treated mice compared to controls led to the identification of DSS-elicited inhibition of stearoyl-CoA desaturase 1 (SCD1) expression in liver. This decrease occurred prior to the symptoms of acute colitis and was well correlated with elevated expression of proinflammatory cytokines. Furthermore, Citrobacter rodentium-induced colitis and lipopolysaccharide treatment also suppressed SCD1 expression in liver. Scd1 null mice were more susceptible to DSS treatment than wild-type mice, while oleic acid feeding and in vivo SCD1 rescue with SCD1 adenovirus alleviated the DSS-induced phenotype. This study reveals that inhibition of SCD1-mediated oleic acid biogenesis exacerbates proinflammatory responses to exogenous challenges, suggesting that SCD1 and its related lipid species may serve as potential targets for intervention or treatment of inflammatory diseases.
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Affiliation(s)
- Chi Chen
- Laboratory of Metabolism, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA
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Zou Y, Kim CH, Chung JH, Kim JY, Chung SW, Kim MK, Im DS, Lee J, Yu BP, Chung HY. Upregulation of endothelial adhesion molecules by lysophosphatidylcholine. Involvement of G protein-coupled receptor GPR4. FEBS J 2007; 274:2573-84. [PMID: 17437524 DOI: 10.1111/j.1742-4658.2007.05792.x] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Lysophosphatidylcholine induces expression of adhesion molecules; however, the underlying molecular mechanisms of this are not well elucidated. In this study, the intracellular signaling by which lysophosphatidylcholine upregulates vascular cell adhesion molecule-1 and P-selectin was delineated using YPEN-1 and HEK293T cells. The results showed that lysophosphatidylcholine dose-dependently induced expression of vascular cell adhesion molecule-1 and P-selectin, accompanied by the activation of transcription factor nuclear factor kappaB. However, the nuclear factor kappaB inhibitor caffeic acid phenethyl ester (CAPE) and the antioxidant N-acetylcysteine only partially blocked lysophosphatidylcholine-induced adhesion molecules. Subsequently, we found that the lysophosphatidylcholine receptor G protein-coupled receptor 4 (GPK4) was expressed in YPEN-1 cells and triggered the cAMP/protein kinase A/cAMP response element-binding protein pathway, resulting in upregulation of adhesion molecules. Further evidence showed that overexpression of human GPK4 enhanced lysophosphatidylcholine-induced expression of adhesion molecules in YPEN-1 cells, and enabled HEK293T cells to express adhesion molecules in response to lysophosphatidylcholine. In conclusion, the current study suggested two pathways by which lysophosphatidylcholine regulates the expression of adhesion molecules, the lysophosphatidylcholine/nuclear factor-kappaB/adhesion molecule and lysophosphatidylcholine/GPK4/cAMP/protein kinase A/cAMP response element-binding protein/adhesion molecule pathways, emphasizing the importance of the lysophosphatidylcholine receptor in regulating endothelial cell function.
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Affiliation(s)
- Yani Zou
- College of Pharmacy, Pusan National University, Gumjung-gu, Busan, Korea
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Seuwen K, Ludwig MG, Wolf RM. Receptors for protons or lipid messengers or both? J Recept Signal Transduct Res 2007; 26:599-610. [PMID: 17118800 DOI: 10.1080/10799890600932220] [Citation(s) in RCA: 101] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
The subfamily of G protein-coupled receptors comprising GPR4, OGR1, TDAG8, and G2A was originally characterized as a group of proteins mediating biological responses to the lipid messengers sphingosylphosphorylcholine (SPC), lysophosphatidylcholine (LPC), and psychosine. We challenged this view by reporting that OGR1 and GPR4 sense acidic pH and that this process is not affected by concentrations of SPC or LPC previously reported as agonistic. The original publications describing GPR4, OGR1, and G2A as receptors for LPC or SPC have now been retracted, and the first studies exploring receptors of this family as pH sensors in physiology have appeared. Here we review the status of this field and we confirm that GPR4, OGR1, and TDAG8 should be considered as proton-sensing receptors. Negative regulation of these receptors by high micromolar concentrations of lipids appears not specific in our experiments.
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Affiliation(s)
- Klaus Seuwen
- Novartis Institutes for Biomedical Research, Basel, Switzerland.
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29
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Yang LV, Radu CG, Roy M, Lee S, McLaughlin J, Teitell MA, Iruela-Arispe ML, Witte ON. Vascular abnormalities in mice deficient for the G protein-coupled receptor GPR4 that functions as a pH sensor. Mol Cell Biol 2006; 27:1334-47. [PMID: 17145776 PMCID: PMC1800706 DOI: 10.1128/mcb.01909-06] [Citation(s) in RCA: 99] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
GPR4 is a G protein-coupled receptor expressed in the vasculature, lung, kidney, and other tissues. In vitro ectopic overexpression studies implicated GPR4 in sensing extracellular pH changes leading to cyclic AMP (cAMP) production. To investigate its biological roles in vivo, we generated GPR4-deficient mice by homologous recombination. Whereas GPR4-null adult mice appeared phenotypically normal, neonates showed a higher frequency of perinatal mortality. The average litter size from GPR4(-/-) intercrosses was approximately 30% smaller than that from GPR4(+/+) intercrosses on N3 and N5 C57BL/6 genetic backgrounds. A fraction of knockout embryos and neonates had spontaneous hemorrhages, dilated and tortuous subcutaneous blood vessels, and defective vascular smooth muscle cell coverage. Mesangial cells in kidney glomeruli were also significantly reduced in GPR4-null neonates. Some neonates exhibited respiratory distress with airway lining cell metaplasia. To examine whether GPR4 is functionally involved in vascular pH sensing, an ex vivo aortic ring assay was used under defined pH conditions. Compared to wild-type aortas, microvessel outgrowth from GPR4-null aortas was less inhibited by acidic extracellular pH. Treatment with an analog of cAMP, a downstream effector of GPR4, abolished microvessel outgrowth bypassing the GPR4-knockout phenotype. These results suggest that GPR4 deficiency leads to partially penetrant vascular abnormalities during development and that this receptor functions in blood vessel pH sensing.
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MESH Headings
- Animals
- Animals, Newborn
- Aorta/abnormalities
- Blood Vessels/abnormalities
- Blood Vessels/embryology
- Cells, Cultured
- Crosses, Genetic
- Embryo, Mammalian/abnormalities
- Embryo, Mammalian/blood supply
- Embryo, Mammalian/pathology
- Female
- Gene Targeting
- Genotype
- Hemorrhage/congenital
- Humans
- Hydrogen-Ion Concentration
- Litter Size
- Lung/abnormalities
- Lung/embryology
- Lung/pathology
- Male
- Mesangial Cells/pathology
- Mice
- Mice, Inbred C57BL
- Mice, Knockout
- Penetrance
- Receptors, G-Protein-Coupled/deficiency
- Receptors, G-Protein-Coupled/metabolism
- Respiratory Tract Diseases/congenital
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Affiliation(s)
- Li V Yang
- Howard Hughes Medical Institute, University of California-Los Angeles, 675 Charles E. Young Drive South, Los Angeles, CA 90095-1662, USA
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30
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Matsumoto T, Kobayashi T, Kamata K. Mechanisms underlying lysophosphatidylcholine-induced potentiation of vascular contractions in the Otsuka Long-Evans Tokushima Fatty (OLETF) rat aorta. Br J Pharmacol 2006; 149:931-41. [PMID: 17031383 PMCID: PMC2014696 DOI: 10.1038/sj.bjp.0706937] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
BACKGROUND AND PURPOSE The effect of lysophosphatidylcholine (LPC) on aortic contractions in Otsuka Long-Evans Tokushima Fatty (OLETF) rats, a type 2 diabetic model, was studied. EXPERIMENTAL APPROACH Using OLETF rats and control (Long Evans Tokushima Otsuka (LETO)) rats, the effects of LPC on the contractions induced by high-K(+) (10-40 mM), UK14,304 (10 approximately 100 nM; a selective alpha(2)-adrenoceptor agonist) and sodium orthovanadate (SOV; 10 microM approximately 3 mM) in endothelium-denuded aortae were compared. Aortic ERK activity and the mRNA expression for GPR4 (a putative LPC receptor) were also measured. KEY RESULTS OLETF rats exhibited (vs. age-matched LETO rats): (1) greater potentiation of high-K(+)-induced contraction by 10 microM LPC - a potentiation attenuated by 10 microM genistein, protein tyrosine kinase (PTK) inhibitor, (2) greater potentiation of UK14,304 (10 approximately 100 nM)-induced contractions by LPC (1 microM approximately 10 microM) - a potentiation attenuated by 10 microM genistein, 50 microM tyrphostin A23 (PTK inhibitor) or 10 microM PD98059 (MEK 1/2 inhibitor), (3) greater basal and LPC (1 microM)-induced ERK activities, (4) greater basal and 100 nM UK14,304-stimulated ERK2 activities in both the absence and presence of 10 microM LPC, (5) greater SOV (10 microM approximately 3 mM)-induced contractions, (6) greater potentiation of SOV-induced contractions by 10 microM LPC - a potentiation suppressed by 10 microM PD98059 or 10 microM genistein, (7) upregulation of GPR4 mRNA. CONCLUSIONS AND IMPLICATIONS These results suggest that the LPC-induced potentiation of contractions in the OLETF rat aorta may be attributable to increased PTKs or ERK activity and/or to receptor upregulation.
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MESH Headings
- Animals
- Aorta, Thoracic/drug effects
- Brimonidine Tartrate
- Diabetes Mellitus, Type 2/physiopathology
- Disease Models, Animal
- Dose-Response Relationship, Drug
- Lysophosphatidylcholines/pharmacology
- MAP Kinase Signaling System/drug effects
- Male
- Muscle, Smooth, Vascular/chemistry
- Muscle, Smooth, Vascular/drug effects
- Muscle, Smooth, Vascular/physiopathology
- Potassium/pharmacology
- Protein Kinase Inhibitors/pharmacology
- Protein Tyrosine Phosphatases/antagonists & inhibitors
- Quinoxalines/pharmacology
- RNA, Messenger/analysis
- Rats
- Rats, Inbred OLETF
- Rats, Long-Evans
- Receptors, G-Protein-Coupled/analysis
- Up-Regulation
- Vanadates
- Vasoconstriction/drug effects
- Vasoconstrictor Agents/pharmacology
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Affiliation(s)
- T Matsumoto
- Department of Physiology and Morphology, Institute of Medicinal Chemistry, Hoshi University Shinagawa-ku, Tokyo, Japan
| | - T Kobayashi
- Department of Physiology and Morphology, Institute of Medicinal Chemistry, Hoshi University Shinagawa-ku, Tokyo, Japan
| | - K Kamata
- Department of Physiology and Morphology, Institute of Medicinal Chemistry, Hoshi University Shinagawa-ku, Tokyo, Japan
- Author for correspondence:
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Parks BW, Lusis AJ, Kabarowski JHS. Loss of the lysophosphatidylcholine effector, G2A, ameliorates aortic atherosclerosis in low-density lipoprotein receptor knockout mice. Arterioscler Thromb Vasc Biol 2006; 26:2703-9. [PMID: 16990555 DOI: 10.1161/01.atv.0000246774.02426.71] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
OBJECTIVE Lysophosphatidylcholine is a major product of low-density lipoprotein (LDL) oxidation and secretory phospholipase A2-mediated lipid hydrolysis within atherosclerotic lesions. The G2A receptor mediates chemotaxis of cultured macrophages and T cells to lysophosphatidylcholine, supporting a pro-atherogenic role for this receptor in vivo. We investigated the ability of G2A to modulate atherosclerosis in mice. METHODS AND RESULTS We measured atherosclerosis in G2A+/+ and G2A-/- LDL receptor knockout (LDLR-/-) mice. Consistent with a previous study, early lesion size at the aortic sinus was unaffected by G2A deficiency. However, G2A deficiency attenuated lesion progression at this site (42% to 44% reduction in average lesion area) and led to robust suppression of atherosclerosis throughout the aorta after short and extended periods of diet intervention (reduction in aortic lesion coverage: 62% to 73% at 9 weeks, 75% to 84% at 20 weeks). In G2A-/- LDLR-/- mice, intimal macrophage accumulation at lesion-prone sites of the aorta was significantly reduced in the absence of any detectable effect on T cell recruitment. Examination of lipoprotein profiles revealed elevated levels of circulating high-density lipoprotein (HDL) cholesterol in G2A-/- LDLR-/- mice compared with their G2A+/+ LDLR-/- counterparts after extended periods of diet intervention (54% increase in mean HDL cholesterol concentration). CONCLUSIONS G2A provides a pro-atherogenic stimulus in vivo consistent with its chemotactic action but to which a pleiotropy of effects, including modulation of lipoprotein metabolism, may also contribute.
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Affiliation(s)
- Brian W Parks
- Department of Microbiology, University of Alabama at Birmingham, 19th St S, Birmingham, AL 35294-2170, USA
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Qiao J, Huang F, Naikawadi RP, Kim KS, Said T, Lum H. Lysophosphatidylcholine impairs endothelial barrier function through the G protein-coupled receptor GPR4. Am J Physiol Lung Cell Mol Physiol 2006; 291:L91-101. [PMID: 16461426 DOI: 10.1152/ajplung.00508.2005] [Citation(s) in RCA: 85] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
Abundant evidence indicates that lysophosphatidylcholine (LPC) is proinflammatory and atherogenic. In the vascular endothelium, LPC increases permeability and expression of proinflammatory molecules such as adhesion molecules and cytokines. Yet, mechanisms by which LPC mediates these activities remain unclear and controversial. Recent evidence implicates involvement of a novel subfamily of G protein-coupled receptors (GPR4, G2A, OGR1, and TDAG8) that are sensitive to lysolipids and protons. We previously reported that one of these receptors, GPR4, is selectively expressed by a variety of endothelial cells and therefore hypothesize that the LPC-stimulated endothelial barrier dysfunction is mediated through GPR4. We developed a peptide Ab against GPR4 that detected GPR4 expression in transfected COS 7 cells and endogenous GPR4 expression in endothelial cells by Western blot. Endothelial cells infected with a retrovirus containing small interference RNA (siRNA) to GPR4 resulted in 40–50% decreased GPR4 expression, which corresponded with partial prevention of the LPC-induced 1) decrease in transendothelial resistance, 2) stress fiber formation, and 3) activation of RhoA. Furthermore, coexpression of the siRNA-GPR4 with a siRNA-resistant mutant GPR4 fully restored the LPC-induced resistance decrease. However, extracellular pH of <7.4 did not alter baseline or LPC-stimulated resistances. The results provide strong evidence that the LPC-mediated endothelial barrier dysfunction is regulated by endogenous GPR4 in endothelial cells and suggest that GPR4 may play a critical role in the inflammatory responses activated by LPC.
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Affiliation(s)
- Jing Qiao
- Rush Univ. Medical Center, Dept. of Pharmacology, 1735 W. Harrison St., Chicago, IL 60612, USA
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Watanabe N, Zmijewski JW, Takabe W, Umezu-Goto M, Le Goffe C, Sekine A, Landar A, Watanabe A, Aoki J, Arai H, Kodama T, Murphy MP, Kalyanaraman R, Darley-Usmar VM, Noguchi N. Activation of mitogen-activated protein kinases by lysophosphatidylcholine-induced mitochondrial reactive oxygen species generation in endothelial cells. THE AMERICAN JOURNAL OF PATHOLOGY 2006; 168:1737-48. [PMID: 16651638 PMCID: PMC1606607 DOI: 10.2353/ajpath.2006.050648] [Citation(s) in RCA: 81] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 01/30/2006] [Indexed: 01/09/2023]
Abstract
Lysophosphatidylcholine (lysoPC) evokes diverse biological responses in vascular cells including Ca(2+) mobilization, production of reactive oxygen species, and activation of the mitogen-activated protein kinases, but the mechanisms linking these events remain unclear. Here, we provide evidence that the response of mitochondria to the lysoPC-dependent increase in cytosolic Ca(2+) leads to activation of the extracellular signal-regulated kinase (ERK) mitogen-activated protein kinase through a redox signaling mechanism in human umbilical vein endothelial cells. ERK activation was attenuated by inhibitors of the electron transport chain proton pumps (rotenone and antimycin A) and an uncoupler (carbonyl cyanide p-trifluoromethoxyphenylhydrazone), suggesting that mitochondrial inner membrane potential plays a key role in the signaling pathway. ERK activation was also selectively attenuated by chain-breaking antioxidants and by vitamin E targeted to mitochondria, suggesting that transduction of the mitochondrial hydrogen peroxide signal is mediated by a lipid peroxidation product. Inhibition of ERK activation with MEK inhibitors (PD98059 or U0126) diminished induction of the antioxidant enzyme heme oxygenase-1. Taken together, these data suggest a role for mitochondrially generated reactive oxygen species and Ca(2+) in the redox cell signaling path-ways, leading to ERK activation and adaptation of the pathological stress mediated by oxidized lipids such as lysoPC.
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Affiliation(s)
- Nobuo Watanabe
- Research Center for Advanced Science and Technology, University of Tokyo, 4-6-1 Komaba, Meguro, Tokyo 153-8904
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Tomura H, Mogi C, Sato K, Okajima F. Proton-sensing and lysolipid-sensitive G-protein-coupled receptors: A novel type of multi-functional receptors. Cell Signal 2005; 17:1466-76. [PMID: 16014326 DOI: 10.1016/j.cellsig.2005.06.002] [Citation(s) in RCA: 132] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2005] [Accepted: 06/03/2005] [Indexed: 11/16/2022]
Abstract
OGR1, GPR4, G2A, and TDAG8 share 40% to 50% homology with each other and seem to form a family of GPCRs. They have been described as receptors for lipid molecules such as sphingosylphosphorylcholine, lysophosphatidylcholine, and psychosine. Recent studies, however, have revealed that these receptors also sense extracellular protons or pH through histidine residues of receptors and stimulate a variety of intracellular signaling pathways through several species of hetero-trimeric G-proteins, including G(s), G(i), G(q), and G(12/13). Thus, this family of GPCR seems to recognize both lipid molecules and protons as ligands. Although our knowledge of proton-sensing and lysolipid-sensitive GPCRs is preliminary, the receptor levels and ligand levels especially protons are both sensitively modulated in response to a variety of microenvironmental changes. These results suggest a multiple role of proton-sensing GPCRs in a variety of physiological and pathophysiological states.
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Affiliation(s)
- Hideaki Tomura
- Laboratory of Signal Transduction, Institute for Molecular and Cellular Regulation, Gunma University, 3-39-15 Showa-machi, Maebashi 371-8512, Japan
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Abstract
Recently, two different chemicals have been matched as ligands with the same G-protein-coupled receptor (GPCR). Double-pairing of OGR1 family GPCRs with proton and lysolipid raises several questions. First, whether both are the real ligands for the GPCRs. Second, whether modulation of a GPCR by two chemicals could be possible. Third, one of the chemicals is proton. Proton-sensing not only is a new action mode of GPCR activation, but also it could be generalized in other GPCRs. In this review, I would like to summarize the issue and discuss questions with pharmacological criteria.
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Affiliation(s)
- Dong-Soon Im
- Laboratory of Pharmacology and Research Institute of Drug Development, College of Pharmacy, Pusan National University, Busan 609-735, Republic of Korea.
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Pexa A, Deussen A. Modulation of ecto-5'-nucleotidase by phospholipids in human umbilical vein endothelial cells (HUVEC). Naunyn Schmiedebergs Arch Pharmacol 2005; 372:131-8. [PMID: 16200394 DOI: 10.1007/s00210-005-0002-9] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2005] [Accepted: 08/11/2005] [Indexed: 10/25/2022]
Abstract
Ecto-5'-nucleotidase, the major enzyme controlling extracellular adenosine production, can be activated by phospholipids, e.g. lysophosphatidylcholine (LPC). This study examined the structural requirements of phospholipids to evoke this enzyme activation and figured out two new activators of ecto-5'-nucleotidase: platelet activating factor (PAF) and sphingosylphosphorylcholine (SPC). Potential signal transduction pathways including an involvement of protein kinase C and PAF-receptor were evaluated on the model of human umbilical vein endothelial cells (HUVEC). Cells were pre-incubated with 10 microM of various phospholipids including lysophosphatidylcholine, beta-arachidonyl-gamma-palmityl-alpha-phosphatidylcholine, beta,gamma-dipalmityl-alpha-phosphatidyl-choline, beta,gamma-dipalmityl-alpha-phosphatidylethanolamine, beta,gamma-dipalmityl-alpha-phosphatidylserine, gamma-acyl-beta-lyso-alpha-phosphatidylethanolamine, beta-acetyl-gamma-O-hexadecyl-alpha-phosphatidylcholine (platelet activating factor), lysophosphatidylic acid, sphingosine-1-phosphate and sphingosylphosphorylcholine. In the cell supernatant the extracellular dephosphorylation rate of the fluorescent AMP-analogue 1,N6-etheno-5'AMP to 1,N6-etheno-adenosine was measured by HPLC. Out of these ten structurally related phospholipids only lysophosphatidylcholine, sphingosylphosphatidylcholine and platelet activating factor dose-dependently increased the activity of ecto-5'-nucleotidase. Pharmacological blocking experiments revealed that neither the activation of PAF-receptor nor of protein kinase C were important for mediating the activation of ecto-5'-nucleotidase. Thus, using information on the known molecular structures of tested phospholipids, a phosphatidylcholine residue in alpha-position and a short chain length fatty acid esterified in beta-position seem essential for activation of ecto-5'-nucleotidase by glycerophospholipids. Since all tested phospholipids have similar fatty acid chain lengths and residues in alpha-position, they should act similarly on membrane fluidity. It is concluded that the observed effects are not based on changes in membrane fluidity by the added phospholipids, but rather involve a yet to be determined phospholipid-receptor.
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Affiliation(s)
- Annette Pexa
- Department of Physiology, Medical Faculty Carl Gustav Carus, Room A20.016, MTZ, TU Dresden, Fetscherstr. 74, 01307, Dresden, Germany.
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Parks BW, Gambill GP, Lusis AJ, Kabarowski JHS. Loss of G2A promotes macrophage accumulation in atherosclerotic lesions of low density lipoprotein receptor-deficient mice. J Lipid Res 2005; 46:1405-15. [PMID: 15834123 DOI: 10.1194/jlr.m500085-jlr200] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Abstract
Lysophosphatidylcholine (LPC) is considered a major proatherogenic component of oxidized low density lipoprotein based on its proinflammatory actions in vitro. LPC stimulates macrophage and T-cell chemotaxis via the G protein-coupled receptor G2A and may thus promote inflammatory cell infiltration during atherosclerotic lesion development. However, G2A also mediates proapoptotic effects of LPC and may therefore promote the death of inflammatory cells within developing lesions. To determine how these effects of LPC modify atherogenesis, we examined atherosclerotic lesion development in G2A-sufficient and G2A-deficient low density lipoprotein receptor knockout mice. Although LPC species capable of activating G2A-dependent responses were increased during lesion development, G2A-deficient mice developed lesions similar in size to those in their G2A-sufficient counterparts. Loss of G2A during atherosclerotic lesion development did not reduce macrophage and T-cell infiltration but instead resulted in increased lesional macrophage content associated with reduced numbers of terminal deoxynucleotidyl transferase-mediated dUTP nick end labeled cells and decreased collagen deposition. These data indicate that the ability of LPC to stimulate macrophage and T-cell chemotaxis via G2A is not manifested in vivo and that G2A-mediated proapoptotic rather than chemotactic action is most penetrant during atherogenesis and may modify the stability of atherosclerotic lesions by promoting macrophage death.
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Affiliation(s)
- Brian W Parks
- Department of Microbiology, University of Alabama, Birmingham, AL 35294-2170, USA
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Huang F, Subbaiah PV, Holian O, Zhang J, Johnson A, Gertzberg N, Lum H. Lysophosphatidylcholine increases endothelial permeability: role of PKCalpha and RhoA cross talk. Am J Physiol Lung Cell Mol Physiol 2005; 289:L176-85. [PMID: 15764646 DOI: 10.1152/ajplung.00003.2005] [Citation(s) in RCA: 82] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
Lysophosphatidylcholine (LPC) is a bioactive proinflammatory lipid that can be generated by pathological activities. We investigated the hypothesis that LPC signals increase in endothelial permeability. Stimulation of human dermal microvascular endothelial cells and bovine pulmonary microvascular endothelial cells with LPC (10-50 microM) induced decreases (within minutes) in transendothelial electrical resistance and increase of endothelial permeability. LPC activated (within 5 min) membrane-associated PKC phosphotransferase activity in the absence of translocation. Affinity-binding analysis indicated that LPC induced increases (also by 5 min) of GTP-bound RhoA, but not Rac1 or Cdc42. By 60 min, both signaling pathways decreased toward baseline. Inhibition of RhoA with C3 transferase inhibited approximately 50% of LPC-induced resistance decrease. Pretreatment with PKC inhibitor Gö-6983 (concentrations selective for classic PKC), PMA-induced depletion of PKCalpha, and transfection of antisense PKCalpha oligonucleotide each prevented 40-50% of the LPC-induced resistance decrease. Furthermore, these three PKC inhibition strategies inhibited 60-80% of the LPC-induced GTP-bound RhoA. These results show that LPC directly impairs the endothelial barrier function that was dependent, at least in part, on cross talk of PKCalpha and RhoA signals. The evidence indicates that elevated LPC levels can contribute to the activation of a proinflammatory endothelial phenotype.
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Affiliation(s)
- Fei Huang
- Department of Pharmacology, Rush Univ. Medical Center, 1735 W. Harrison St., Cohn Research Bldg., Rm. 416, Chicago, IL 60612, USA
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Kim KS, Ren J, Jiang Y, Ebrahem Q, Tipps R, Cristina K, Xiao YJ, Qiao J, Taylor KL, Lum H, Anand-Apte B, Xu Y. GPR4 plays a critical role in endothelial cell function and mediates the effects of sphingosylphosphorylcholine. FASEB J 2005; 19:819-21. [PMID: 15857892 DOI: 10.1096/fj.04-2988fje] [Citation(s) in RCA: 54] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Angiogenesis is critical for many physiological and pathological processes. We show here that the lipid sphingosylphosphorylcholine (SPC) induces angiogenesis in vivo and GPR4 is required for the biological effects of SPC on endothelial cells (EC). In human umbilical vein EC, down-regulation of GPR4 specifically inhibits SPC-, but not sphingosine-1-phosphate-, or vascular endothelial growth factor (VEGF)-induced tube formation. Re-introduction of GPR4 fully restores the activity of SPC. In microvascular EC, GPR4 plays a pivotal role in cell survival, growth, migration, and tube formation through both SPC-dependent and -independent pathways. The biological effects resulting from SPC/GPR4 interactions involve the activation of both phosphatidylinositol-3 kinase and Akt. Moreover, the effects of SPC on EC require SPC induced trans-phosphorylation and activation of the VEGF receptor 2. These results identify SPC and its receptor, GPR4, as critical regulators of the angiogenic potential of EC.
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Affiliation(s)
- Kwan-Sik Kim
- Department of Cancer Biology, Lerner Research Institute, The Cleveland Clinic Foundation, Cleveland, Ohio 44195, USA
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Gay I, Schwartz Z, Sylvia VL, Boyan BD. Lysophospholipid regulates release and activation of latent TGF-beta1 from chondrocyte extracellular matrix. Biochim Biophys Acta Mol Cell Biol Lipids 2004; 1684:18-28. [PMID: 15450206 DOI: 10.1016/j.bbalip.2004.04.006] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2003] [Revised: 04/20/2004] [Accepted: 04/26/2004] [Indexed: 10/26/2022]
Abstract
Transforming growth factor beta-1 (TGF-beta1) is released from the extracellular matrix of rat growth plate chondrocytes and activated by stromelysin-1 (matrix metalloproteinase 3, MMP-3), an enzyme that is stored in matrix vesicles. MMP-3 is released from these extracellular organelles by the direct action of 1alpha,25(OH)2D3 via activation of phospholipase A2 (PLA2), resulting in local production of lysophospholipids and matrix vesicle membrane destabilization. This effect of 1alpha,25(OH)2D3 is greater in matrix vesicles from growth zone chondrocyte cultures and PLA2 activity is higher in the growth zone in vivo, suggesting that it may depend on chondrocyte maturation state in the endochondral lineage. Previous studies have shown that latent TGF-beta1 can be activated by mild detergents in vitro, suggesting that lysophospholipids may act in vivo in a similar manner. To test this hypothesis, we determined if rat costochondral growth plate cartilage cells produce lysophosphatidylcholine (LPC) and lysophosphatidylethanolamine (LPE) in a maturation state-dependent manner and if LPC or LPE could release and activate latent TGF-beta1 from the extracellular matrix produced by these cells. Rat growth plate chondrocytes produced both lysophospholipids, with growth zone cells producing higher levels of LPE via PLA1, and resting zone cells producing higher levels of LPC via PLA2. LPC and LPE directly increased activation of recombinant human latent TGF-beta1 in a biphasic manner with a peak at 2 microg/ml. Phosphatidylcholine, phosphatidylethanolamine, and LPE plasmalogen (LPEP), but not choline, also activated TGF-beta1. Latent TGF-beta1 incubated with LPC or LPE, but neither lysophospholipid alone, stimulated [3H]-thymidine incorporation of resting zone cells, indicating the TGF-beta1 released was biologically active. LPC and LPE also released TGF-beta1 in a dose- and time-dependent manner when incubated with cell-free extracellular matrices produced by the cells. These results indicate that LPC and LPE have important roles as regulators of rat growth plate chondrocytes by directly and indirectly activating TGF-beta1 stored in the extracellular matrix.
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Affiliation(s)
- I Gay
- University of Texas Health Science Center at San Antonio, San Antonio, TX, USA
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Millanvoye-Van Brussel E, Topal G, Brunet A, Do Pham T, Deckert V, Rendu F, David-Dufilho M. Lysophosphatidylcholine and 7-oxocholesterol modulate Ca2+ signals and inhibit the phosphorylation of endothelial NO synthase and cytosolic phospholipase A2. Biochem J 2004; 380:533-9. [PMID: 14992685 PMCID: PMC1224183 DOI: 10.1042/bj20040069] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2004] [Revised: 02/16/2004] [Accepted: 03/01/2004] [Indexed: 11/17/2022]
Abstract
The oxidation of plasma LDLs (low-density lipoproteins) is a key event in the pathogenesis of atherosclerosis. LPC (lysophosphatidylcholine) and oxysterols are major lipid constitutents of oxidized LDLs. In particular, 7-oxocholesterol has been found in plasma from cardiac patients and atherosclerotic plaque. In the present study, we investigated the ability of 7-oxocholesterol and LPC to regulate the activation of eNOS (endothelial nitric oxide synthase) and cPLA2 (cytosolic phospholipase A2) that synthesize two essential factors for vascular wall integrity, NO (nitric oxide) and arachidonic acid. In endothelial cells from human umbilical vein cords, both 7-oxocholesterol (150 microM) and LPC (20 microM) decreased histamine-induced NO release, but not the release activated by thapsigargin. The two lipids decreased NO release through a PI3K (phosphoinositide 3-kinase)-dependent pathway, and decreased eNOS phosphorylation. Their mechanisms of action were, however, different. The NO release reduction was dependent on superoxide anions in LPC-treated cells and not in 7-oxocholesterol-treated ones. The Ca2+ signals induced by histamine were abolished by LPC, but not by 7-oxocholesterol. The oxysterol also inhibited (i) the histamine- and thapsigargin-induced arachidonic acid release, and (ii) the phosphorylation of both cPLA2 and ERK1/2 (extracellular-signal-regulated kinases 1/2). The results show that 7-oxocholesterol inhibits eNOS and cPLA2 activation by altering a Ca2+-independent upstream step of PI3K and ERK1/2 cascades, whereas LPC desensitizes eNOS by interfering with receptor-activated signalling pathways. This suggests that 7-oxocholesterol and LPC generate signals which cross-talk with heterologous receptors, effects which could appear at early stage of atherosclerosis.
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Yang LV, Radu CG, Wang L, Riedinger M, Witte ON. Gi-independent macrophage chemotaxis to lysophosphatidylcholine via the immunoregulatory GPCR G2A. Blood 2004; 105:1127-34. [PMID: 15383458 DOI: 10.1182/blood-2004-05-1916] [Citation(s) in RCA: 135] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
G2A is a G-protein-coupled receptor (GPCR) involved in immune regulation. Previous studies have shown that lysophosphatidylcholine (LPC), a bioactive lipid associated with atherosclerosis and autoimmunity, acts through G2A to induce diverse biologic effects. Production of LPC during cell apoptosis serves as a chemotactic signal for macrophage recruitment. Here we demonstrate that macrophage chemotaxis to LPC is dependent on G2A function. Wild-type but not G2A-deficient mouse peritoneal macrophages migrated toward LPC. RNAi-mediated knockdown of G2A in J774A.1 macrophages abolished LPC-induced chemotaxis, whereas overexpression of G2A significantly enhanced this process. Mutation of the conserved DRY motif of G2A resulted in loss of chemotaxis to LPC, suggesting a requirement for G-protein signaling. Unlike most GPCRs, including the chemokine receptors, coupling to G(i) is not required for LPC/G2A-mediated chemotaxis, but coupling to G(q/11) and G(12/13) is necessary as judged by inhibition with dominant negative forms of these alpha subunits or with regulators of G-protein signaling (RGS) constructs. Collectively, these data establish that pertussis toxin-insensitive G2A signaling regulates macrophage chemotaxis to LPC. Defects in this signaling pathway may be related to the pathogenesis of systemic autoimmune disease.
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Affiliation(s)
- Li V Yang
- Howard Hughes Medical Institute, Department of Microbiology, Immunology and Molecular Genetics, University of California Los Angeles, 675 Charles E. Young Dr South, 5-748 MRL, Los Angeles, CA 90095-1662, USA
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