1
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Lescop C, Brotschi C, Williams JT, Sager CP, Birker M, Morrison K, Froidevaux S, Delahaye S, Nayler O, Bolli MH. Discovery of a Novel Orally Active, Selective LPA Receptor Type 1 Antagonist, 4-(4-(2-Isopropylphenyl)-4-((2-methoxy-4-methylphenyl)carbamoyl)piperidin-1-yl)-4-oxobutanoic Acid, with a Distinct Molecular Scaffold. J Med Chem 2024; 67:2379-2396. [PMID: 38349223 DOI: 10.1021/acs.jmedchem.3c01826] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/23/2024]
Abstract
Lysophosphatidic acid receptor 1 (LPAR1) antagonists show promise as potentially novel antifibrotic treatments. In a human LPAR1 β-arrestin recruitment-based high-throughput screening campaign, we identified urea 19 as a hit with a LPAR1 IC50 value of 5.0 μM. Hit-to-lead activities revealed that one of the urea nitrogen atoms can be replaced by carbon and establish the corresponding phenylacetic amide as a lead structure for further optimization. Medicinal chemistry efforts led to the discovery of piperidine 18 as a potent and selective LPAR1 antagonist with oral activity in a mouse model of LPA-induced skin vascular leakage. The molecular scaffold of 18 shares no obvious structural similarity with any other LPAR1 antagonist disclosed so far.
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Affiliation(s)
- Cyrille Lescop
- DD Chemistry, Idorsia Pharmaceuticals, Ltd, Hegenheimermattweg 91, CH-4123 Allschwil, Switzerland
| | - Christine Brotschi
- DD Chemistry, Idorsia Pharmaceuticals, Ltd, Hegenheimermattweg 91, CH-4123 Allschwil, Switzerland
| | - Jodi T Williams
- DD Chemistry, Idorsia Pharmaceuticals, Ltd, Hegenheimermattweg 91, CH-4123 Allschwil, Switzerland
| | - Christoph P Sager
- DD Chemistry, Idorsia Pharmaceuticals, Ltd, Hegenheimermattweg 91, CH-4123 Allschwil, Switzerland
| | - Magdalena Birker
- DD Biology, Idorsia Pharmaceuticals, Ltd, Hegenheimermattweg 91, CH-4123 Allschwil, Switzerland
| | - Keith Morrison
- DD Pharmacology, Idorsia Pharmaceuticals, Ltd, Hegenheimermattweg 91, CH-4123 Allschwil, Switzerland
| | - Sylvie Froidevaux
- DD Pharmacology, Idorsia Pharmaceuticals, Ltd, Hegenheimermattweg 91, CH-4123 Allschwil, Switzerland
| | - Stéphane Delahaye
- Preclinical DMPK, Idorsia Pharmaceuticals, Ltd, Hegenheimermattweg 91, CH-4123 Allschwil, Switzerland
| | - Oliver Nayler
- DD Biology, Idorsia Pharmaceuticals, Ltd, Hegenheimermattweg 91, CH-4123 Allschwil, Switzerland
| | - Martin H Bolli
- DD Chemistry, Idorsia Pharmaceuticals, Ltd, Hegenheimermattweg 91, CH-4123 Allschwil, Switzerland
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Lescop C, Birker M, Brotschi C, Bürki C, Morrison K, Froidevaux S, Delahaye S, Nayler O, Bolli MH. Discovery of the Novel, Orally Active, and Selective LPA1 Receptor Antagonist ACT-1016-0707 as a Preclinical Candidate for the Treatment of Fibrotic Diseases. J Med Chem 2024; 67:2397-2424. [PMID: 38349250 DOI: 10.1021/acs.jmedchem.3c01827] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/23/2024]
Abstract
Piperidine 3 is a potent and selective lysophosphatidic acid receptor subtype 1 receptor (LPAR1) antagonist that has shown efficacy in a skin vascular leakage target engagement model in mice. However, compound 3 has very high human plasma protein binding and high clearance in rats, which could significantly hamper its clinical development. Continued lead optimization led to the potent, less protein bound, metabolically stable, and orally active azetidine 17. Rat pharmacokinetics (PK) studies revealed that 17 accumulated in the liver. In vitro studies indicated that 17 is an organic anion co-transporting polypeptide 1B1 (OATP1B1) substrate. Although analogue 24 was no longer a substrate of OATP1B1, PK studies suggested that the compound undergoes enterohepatic recirculation. Replacing the carboxylic acidic side chain by a non-acidic sulfamide moiety and further fine-tuning of the scaffold yielded the potent, orally active LPAR1 antagonist 49, which was selected for preclinical development for the treatment of fibrotic diseases.
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Affiliation(s)
- Cyrille Lescop
- DD Chemistry, Idorsia Pharmaceuticals, Ltd, Hegenheimermattweg 91, CH-4123 Allschwil, Switzerland
| | - Magdalena Birker
- DD Biology, Idorsia Pharmaceuticals, Ltd, Hegenheimermattweg 91, CH-4123 Allschwil, Switzerland
| | - Christine Brotschi
- DD Chemistry, Idorsia Pharmaceuticals, Ltd, Hegenheimermattweg 91, CH-4123 Allschwil, Switzerland
| | - Cédric Bürki
- Chemistry Process R&D, Idorsia Pharmaceuticals, Ltd, Hegenheimermattweg 91, CH-4123 Allschwil, Switzerland
| | - Keith Morrison
- DD Pharmacology, Idorsia Pharmaceuticals, Ltd, Hegenheimermattweg 91, CH-4123 Allschwil, Switzerland
| | - Sylvie Froidevaux
- DD Pharmacology, Idorsia Pharmaceuticals, Ltd, Hegenheimermattweg 91, CH-4123 Allschwil, Switzerland
| | - Stéphane Delahaye
- Preclinical DMPK, Idorsia Pharmaceuticals, Ltd, Hegenheimermattweg 91, CH-4123 Allschwil, Switzerland
| | - Oliver Nayler
- DD Biology, Idorsia Pharmaceuticals, Ltd, Hegenheimermattweg 91, CH-4123 Allschwil, Switzerland
| | - Martin H Bolli
- DD Chemistry, Idorsia Pharmaceuticals, Ltd, Hegenheimermattweg 91, CH-4123 Allschwil, Switzerland
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3
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Hong JM, Lee JW, Seen DS, Jeong JY, Huh WK. LPA1-mediated inhibition of CXCR4 attenuates CXCL12-induced signaling and cell migration. Cell Commun Signal 2023; 21:257. [PMID: 37749552 PMCID: PMC10518940 DOI: 10.1186/s12964-023-01261-7] [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: 02/13/2023] [Accepted: 08/09/2023] [Indexed: 09/27/2023] Open
Abstract
BACKGROUND G protein-coupled receptor heteromerization is believed to exert dynamic regulatory impact on signal transduction. CXC chemokine receptor 4 (CXCR4) and its ligand CXCL12, both of which are overexpressed in many cancers, play a pivotal role in metastasis. Likewise, lysophosphatidic acid receptor 1 (LPA1) is implicated in cancer cell proliferation and migration. In our preliminary study, we identified LPA1 as a prospective CXCR4 interactor. In the present study, we investigated in detail the formation of the CXCR4-LPA1 heteromer and characterized the unique molecular features and function of this heteromer. METHODS We employed bimolecular fluorescence complementation, bioluminescence resonance energy transfer, and proximity ligation assays to demonstrate heteromerization between CXCR4 and LPA1. To elucidate the distinctive molecular characteristics and functional implications of the CXCR4-LPA1 heteromer, we performed various assays, including cAMP, BRET for G protein activation, β-arrestin recruitment, ligand binding, and transwell migration assays. RESULTS We observed that CXCR4 forms heteromers with LPA1 in recombinant HEK293A cells and the human breast cancer cell line MDA-MB-231. Coexpression of LPA1 with CXCR4 reduced CXCL12-mediated cAMP inhibition, ERK activation, Gαi/o activation, and β-arrestin recruitment, while CXCL12 binding to CXCR4 remained unaffected. In contrast, CXCR4 had no impact on LPA1-mediated signaling. The addition of lysophosphatidic acid (LPA) further hindered CXCL12-induced Gαi/o recruitment to CXCR4. LPA or alkyl-OMPT inhibited CXCL12-induced migration in various cancer cells that endogenously express both CXCR4 and LPA1. Conversely, CXCL12-induced calcium signaling and migration were increased in LPAR1 knockout cells, and LPA1-selective antagonists enhanced CXCL12-induced Gαi/o signaling and cell migration in the parental MDA-MB-231 cells but not in LPA1-deficient cells. Ultimately, complete inhibition of cell migration toward CXCL12 and alkyl-OMPT was only achieved in the presence of both CXCR4 and LPA1 antagonists. CONCLUSIONS The presence and impact of CXCR4-LPA1 heteromers on CXCL12-induced signaling and cell migration have been evidenced across various cell lines. This discovery provides crucial insights into a valuable regulatory mechanism of CXCR4 through heteromerization. Moreover, our findings propose a therapeutic potential in combined CXCR4 and LPA1 inhibitors for cancer and inflammatory diseases associated with these receptors, simultaneously raising concerns about the use of LPA1 antagonists alone for such conditions. Video Abstract.
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Affiliation(s)
- Jong Min Hong
- School of Biological Sciences, Seoul National University, Seoul, 08826, Republic of Korea
| | - Jin-Woo Lee
- School of Biological Sciences, Seoul National University, Seoul, 08826, Republic of Korea
| | - Dong-Seung Seen
- GPCR Therapeutics Inc, Gwanak-Gu, Seoul, 08790, Republic of Korea
| | - Jae-Yeon Jeong
- GPCR Therapeutics Inc, Gwanak-Gu, Seoul, 08790, Republic of Korea.
| | - Won-Ki Huh
- School of Biological Sciences, Seoul National University, Seoul, 08826, Republic of Korea.
- Institute of Microbiology, Seoul National University, Seoul, 08826, Republic of Korea.
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4
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Rivera R, Williams NA, Kennedy GG, Sánchez-Pavón P, Chun J. Generation of an Lpar1-EGFP Fusion Knock-in Transgenic Mouse Line. Cell Biochem Biophys 2021; 79:619-627. [PMID: 34652685 PMCID: PMC8551097 DOI: 10.1007/s12013-021-01033-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/27/2021] [Indexed: 10/25/2022]
Abstract
Lysophosphatidic acid (LPA) is a lysophospholipid that acts as an extracellular signal through the activation of cognate G protein-coupled receptors (GPCRs). There are six known LPA receptors (LPA1-6). The first such receptor, LPA1, was identified in the embryonic brain and has been studied extensively for gene expression throughout the body, including through studies of receptor-null mice. However, identifying receptor protein expression in situ and in vivo within living cells and tissues has been difficult because of biologically low receptor expression and variable antibody specificity. To visualize native LPA1 receptor expression in situ, we generated a knock-in mouse produced by homologous recombination in murine embryonic stem (ES) cells to replace a wildtype Lpar1 allele with a mutant allele created by in-frame fusion of EGFP to the 4th exon of Lpar1 (Lpar1-EGFP knock-in allele). Homozygous knock-in mice appeared normal and the expected mendelian ratios of knock-in allele transmission were present in females and males. Histological assessments of the fetal and adult central nervous system (CNS) demonstrated expression patterns that were consistent with prior in situ hybridization studies. This new mouse line will be useful for studies of LPA1 in the developing and adult CNS, as well as other tissues, and for receptor assessments in living tissues and disease models.
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Affiliation(s)
- Richard Rivera
- Translational Neuroscience Initiative, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA, USA
| | - Nyssa A Williams
- Translational Neuroscience Initiative, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA, USA
| | - Grace G Kennedy
- Translational Neuroscience Initiative, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA, USA
| | - Paloma Sánchez-Pavón
- Translational Neuroscience Initiative, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA, USA
| | - Jerold Chun
- Translational Neuroscience Initiative, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA, USA.
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5
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Terao R, Kaneko H. Lipid Signaling in Ocular Neovascularization. Int J Mol Sci 2020; 21:ijms21134758. [PMID: 32635437 PMCID: PMC7369954 DOI: 10.3390/ijms21134758] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2020] [Revised: 07/02/2020] [Accepted: 07/02/2020] [Indexed: 12/13/2022] Open
Abstract
Vasculogenesis and angiogenesis play a crucial role in embryonic development. Pathological neovascularization in ocular tissues can lead to vision-threatening vascular diseases, including proliferative diabetic retinopathy, retinal vein occlusion, retinopathy of prematurity, choroidal neovascularization, and corneal neovascularization. Neovascularization involves various cellular processes and signaling pathways and is regulated by angiogenic factors such as vascular endothelial growth factor (VEGF) and hypoxia-inducible factor (HIF). Modulating these circuits may represent a promising strategy to treat ocular neovascular diseases. Lipid mediators derived from membrane lipids are abundantly present in most tissues and exert a wide range of biological functions by regulating various signaling pathways. In particular, glycerophospholipids, sphingolipids, and polyunsaturated fatty acids exert potent pro-angiogenic or anti-angiogenic effects, according to the findings of numerous preclinical and clinical studies. In this review, we summarize the current knowledge regarding the regulation of ocular neovascularization by lipid mediators and their metabolites. A better understanding of the effects of lipid signaling in neovascularization may provide novel therapeutic strategies to treat ocular neovascular diseases and other human disorders.
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Affiliation(s)
- Ryo Terao
- Department of Ophthalmology, Graduate School of Medicine, The University of Tokyo, Tokyo 113-0033, Japan
- Correspondence: ; Tel.: +81-3-3815-5411
| | - Hiroki Kaneko
- Department of Ophthalmology, Nagoya University Graduate School of Medicine, Nagoya 466-8550, Japan;
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6
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Piscitelli F, Silvestri C. Role of the Endocannabinoidome in Human and Mouse Atherosclerosis. Curr Pharm Des 2020; 25:3147-3164. [PMID: 31448709 DOI: 10.2174/1381612825666190826162735] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2019] [Accepted: 08/21/2019] [Indexed: 12/20/2022]
Abstract
The Endocannabinoid (eCB) system and its role in many physiological and pathological conditions is well described and accepted, and includes cardiovascular disorders. However, the eCB system has been expanded to an "-ome"; the endocannabinoidome (eCBome) that includes endocannabinoid-related mediators, their protein targets and metabolic enzymes, many of which significantly impact upon cardiometabolic health. These recent discoveries are here summarized with a special focus on their potential involvement in atherosclerosis. We described the role of classical components of the eCB system (eCBs, CB1 and CB2 receptors) and eCB-related lipids, their regulatory enzymes and molecular targets in atherosclerosis. Furthermore, since increasing evidence points to significant cross-talk between the eCBome and the gut microbiome and the gut microbiome and atherosclerosis, we explore the possibility that a gut microbiome - eCBome axis has potential implications in atherosclerosis.
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Affiliation(s)
- Fabiana Piscitelli
- Institute of Biomolecular Chemistry, National Council of Research, Pozzuoli (NA), Italy
| | - Cristoforo Silvestri
- Institut universitaire de cardiologie et de pneumologie de Québec (IUCPQ), 2725 Chemin Sainte-Foy, Québec, QC, G1V 4G5, Canada.,Department of Medicine, Faculty of Medicine, Laval University, Quebec City, QC, Canada
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7
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Jung JH, Han S, Ju M, Jung ST, Yu YG. Isolation of Single Chain Antibodies Specific to Lysophosphatidic Acid Receptor 1 (LPA
1
) from a M13 Phage Display Library Using Purified LPA
1
Stabilized in Nanodiscs. B KOREAN CHEM SOC 2019. [DOI: 10.1002/bkcs.11751] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Affiliation(s)
- Ji Hae Jung
- Department of Applied ChemistryKookmin University Seoul 02707 South Korea
| | - Seong‐Gu Han
- Department of Applied ChemistryKookmin University Seoul 02707 South Korea
| | - Man‐Seok Ju
- Department of Applied ChemistryKookmin University Seoul 02707 South Korea
| | - Sang Taek Jung
- Graduate School of MedicineKorea University Seoul 02841 South Korea
| | - Yeon Gyu Yu
- Department of Applied ChemistryKookmin University Seoul 02707 South Korea
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8
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Suckau O, Gross I, Schrötter S, Yang F, Luo J, Wree A, Chun J, Baska D, Baumgart J, Kano K, Aoki J, Bräuer AU. LPA 1 , LPA 2 , LPA 4 , and LPA 6 receptor expression during mouse brain development. Dev Dyn 2019; 248:375-395. [PMID: 30847983 PMCID: PMC6593976 DOI: 10.1002/dvdy.23] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2018] [Revised: 02/27/2019] [Accepted: 03/02/2019] [Indexed: 12/17/2022] Open
Abstract
Background LPA is a small bioactive phospholipid that acts as an extracellular signaling molecule and is involved in cellular processes, including cell proliferation, migration, and differentiation. LPA acts by binding and activating at least six known G protein–coupled receptors: LPA1–6. In recent years, LPA has been suggested to play an important role both in normal neuronal development and under pathological conditions in the nervous system. Results We show the expression pattern of LPA receptors during mouse brain development by using qRT‐PCR, in situ hybridization, and immunocytochemistry. Only LPA1, LPA2,LPA4, and LPA6 mRNA transcripts were detected throughout development stages from embryonic day 16 until postnatal day 30 of hippocampus, neocortex, cerebellum, and bulbus olfactorius in our experiments, while expression of LPA3 and LPA5 genes was below detection level. In addition to our qRT‐PCR results, we also analyzed the cellular protein expression of endogenous LPA receptors, with focus on LPA1 and LPA2 within postnatal brain slices and primary neuron differentiation with and without cytoskeleton stabilization and destabilization. Conclusions The expression of LPA receptors changes depends on the developmental stage in mouse brain and in cultured hippocampal primary neurons. Interestingly, we found that commercially available antibodies for LPA receptors are largely unspecific. LPA1, ‐2, ‐4, and ‐6 genes are dynamically expressed during postnatal brain development. LPA1, ‐2, ‐4, and ‐6 genes are differently expressed in the hippocampus, neocortex, cerebellum, and bulbus olfactorius. LPA1 and ‐2 gene expression alters during neuronal differentiation. LPA1, ‐2, ‐3, ‐4, and ‐6 genes are expressed in glia cells, but differed in gene expression levels.
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Affiliation(s)
- Olga Suckau
- Institute of Cell Biology and Neurobiology, Center for Anatomy, Charité-Universitätsmedizin Berlin, Berlin, Germany
| | - Isabel Gross
- Institute of Anatomy, Universitätsmedizin Rostock, Rostock, Germany.,Research Group Anatomy, School of Medicine and Health Sciences, Carl von Ossietzky University Oldenburg, Oldenburg, Germany
| | - Sandra Schrötter
- Institute of Cell Biology and Neurobiology, Center for Anatomy, Charité-Universitätsmedizin Berlin, Berlin, Germany
| | - Fan Yang
- Albrecht Kossel Institute for Neuroregeneration, Rostock University Medical Center, Rostock, Germany
| | - Jiankai Luo
- Albrecht Kossel Institute for Neuroregeneration, Rostock University Medical Center, Rostock, Germany
| | - Andreas Wree
- Institute of Anatomy, Universitätsmedizin Rostock, Rostock, Germany
| | - Jerold Chun
- Department of Molecular and Cellular Neuroscience, The Scripps Research Institute, La Jolla, California
| | - David Baska
- Translational Animal Research Center, University Medical Center of the Johannes Gutenberg-University Mainz, Mainz, Germany
| | - Jan Baumgart
- Translational Animal Research Center, University Medical Center of the Johannes Gutenberg-University Mainz, Mainz, Germany
| | - Kuniyuki Kano
- Graduate School of Pharmaceutical Science, University of Tokyo, Tokyo, Japan
| | - Junken Aoki
- Graduate School of Pharmaceutical Science, University of Tokyo, Tokyo, Japan
| | - Anja U Bräuer
- Institute of Cell Biology and Neurobiology, Center for Anatomy, Charité-Universitätsmedizin Berlin, Berlin, Germany.,Institute of Anatomy, Universitätsmedizin Rostock, Rostock, Germany.,Research Group Anatomy, School of Medicine and Health Sciences, Carl von Ossietzky University Oldenburg, Oldenburg, Germany.,Research Center for Neurosensory Science, Carl von Ossietzky University Oldenburg, Oldenburg, Germany
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9
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Thompson KE, Ray RM, Alli S, Ge W, Boler A, Shannon McCool W, Meena AS, Shukla PK, Rao R, Johnson LR, Miller MA, Tigyi GJ. Prevention and treatment of secretory diarrhea by the lysophosphatidic acid analog Rx100. Exp Biol Med (Maywood) 2018; 243:1056-1065. [PMID: 30253666 DOI: 10.1177/1535370218803349] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
IMPACT STATEMENT A critical barrier in treating diarrheal disease is easy-to-use effective treatments. Rx100 is a first in class, novel small molecule that has shown efficacy after both subcutaneous and oral administration in a mouse cholera-toxin- and Citrobacter rodentium infection-induced diarrhea models. Our findings indicate that Rx100 a metabolically stable analog of the lipid mediator lysophosphatidic acid blocks activation of CFTR-mediated secretion responsible for fluid discharge in secretory diarrhea. Rx100 represents a new treatment modality which does not directly block CFTR but attenuates its activation by bacterial toxins. Our results provide proof-of-principle that Rx100 can be developed for use as an effective oral or injectable easy-to-use drug for secretory diarrhea which could significantly improve care by eliminating the need for severely ill patients to regularly consume large quantities of oral rehydration therapies and offering options for pediatric patients.
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Affiliation(s)
- Karin E Thompson
- 1 RxBio, Inc., Johnson City, TN 37604, USA.,*These authors contributed equally to this paper
| | - Ramesh M Ray
- 1 RxBio, Inc., Johnson City, TN 37604, USA.,*These authors contributed equally to this paper
| | | | - Wenbo Ge
- 1 RxBio, Inc., Johnson City, TN 37604, USA
| | | | | | - Avtar S Meena
- 2 Department of Physiology, The University of Tennessee Health Science Center, Memphis, TN 38163, USA
| | - Pradeep K Shukla
- 2 Department of Physiology, The University of Tennessee Health Science Center, Memphis, TN 38163, USA
| | - Radakrishna Rao
- 2 Department of Physiology, The University of Tennessee Health Science Center, Memphis, TN 38163, USA
| | - Leonard R Johnson
- 1 RxBio, Inc., Johnson City, TN 37604, USA.,2 Department of Physiology, The University of Tennessee Health Science Center, Memphis, TN 38163, USA
| | - Mark A Miller
- 3 Microbiology Immunology and Biochemistry, The University of Tennessee Health Science Center, Memphis, TN 38163, USA
| | - Gabor J Tigyi
- 1 RxBio, Inc., Johnson City, TN 37604, USA.,2 Department of Physiology, The University of Tennessee Health Science Center, Memphis, TN 38163, USA
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10
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Kritikou E, van Puijvelde GHM, van der Heijden T, van Santbrink PJ, Swart M, Schaftenaar FH, Kröner MJ, Kuiper J, Bot I. Inhibition of lysophosphatidic acid receptors 1 and 3 attenuates atherosclerosis development in LDL-receptor deficient mice. Sci Rep 2016; 6:37585. [PMID: 27883026 PMCID: PMC5121611 DOI: 10.1038/srep37585] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2016] [Accepted: 10/31/2016] [Indexed: 02/08/2023] Open
Abstract
Lysophosphatidic acid (LPA) is a natural lysophospholipid present at high concentrations within lipid-rich atherosclerotic plaques. Upon local accumulation in the damaged vessels, LPA can act as a potent activator for various types of immune cells through its specific membrane receptors LPA1/3. LPA elicits chemotactic, pro-inflammatory and apoptotic effects that lead to atherosclerotic plaque progression. In this study we aimed to inhibit LPA signaling by means of LPA1/3 antagonism using the small molecule Ki16425. We show that LPA1/3 inhibition significantly impaired atherosclerosis progression. Treatment with Ki16425 also resulted in reduced CCL2 production and secretion, which led to less monocyte and neutrophil infiltration. Furthermore, we provide evidence that LPA1/3 blockade enhanced the percentage of non-inflammatory, Ly6Clow monocytes and CD4+ CD25+ FoxP3+ T-regulatory cells. Finally, we demonstrate that LPA1/3 antagonism mildly reduced plasma LDL cholesterol levels. Therefore, pharmacological inhibition of LPA1/3 receptors may prove a promising approach to diminish atherosclerosis development.
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Affiliation(s)
- Eva Kritikou
- Division of Biopharmaceutics, LACDR, Leiden University, The Netherlands
| | | | | | | | - Maarten Swart
- Division of Biopharmaceutics, LACDR, Leiden University, The Netherlands
| | | | - Mara J Kröner
- Division of Biopharmaceutics, LACDR, Leiden University, The Netherlands
| | - Johan Kuiper
- Division of Biopharmaceutics, LACDR, Leiden University, The Netherlands
| | - Ilze Bot
- Division of Biopharmaceutics, LACDR, Leiden University, The Netherlands
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11
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YU ZILI, LI DIANQI, HUANG XIANGYU, XING XIN, YU RUQING, LI ZHI, LI ZUBING. Lysophosphatidic acid upregulates connective tissue growth factor expression in osteoblasts through the GPCR/PKC and PKA pathways. Int J Mol Med 2016; 37:468-74. [DOI: 10.3892/ijmm.2016.2450] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2015] [Accepted: 12/29/2015] [Indexed: 11/05/2022] Open
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12
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Burkhalter RJ, Westfall SD, Liu Y, Stack MS. Lysophosphatidic Acid Initiates Epithelial to Mesenchymal Transition and Induces β-Catenin-mediated Transcription in Epithelial Ovarian Carcinoma. J Biol Chem 2015; 290:22143-54. [PMID: 26175151 DOI: 10.1074/jbc.m115.641092] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2015] [Indexed: 11/06/2022] Open
Abstract
During tumor progression, epithelial ovarian cancer (EOC) cells undergo epithelial-to-mesenchymal transition (EMT), which influences metastatic success. Mutation-dependent activation of Wnt/β-catenin signaling has been implicated in gain of mesenchymal phenotype and loss of differentiation in several solid tumors; however, similar mutations are rare in most EOC histotypes. Nevertheless, evidence for activated Wnt/β-catenin signaling in EOC has been reported, and immunohistochemical analysis of human EOC tumors demonstrates nuclear staining in all histotypes. This study addresses the hypothesis that the bioactive lipid lysophosphatidic acid (LPA), prevalent in the EOC microenvironment, functions to regulate EMT in EOC. Our results demonstrate that LPA induces loss of junctional β-catenin, stimulates clustering of β1 integrins, and enhances the conformationally active population of surface β1 integrins. Furthermore, LPA treatment initiates nuclear translocation of β-catenin and transcriptional activation of Wnt/β-catenin target genes resulting in gain of mesenchymal marker expression. Together these data suggest that LPA initiates EMT in ovarian tumors through β1-integrin-dependent activation of Wnt/β-catenin signaling, providing a novel mechanism for mutation-independent activation of this pathway in EOC progression.
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Affiliation(s)
- Rebecca J Burkhalter
- From the Departments of Medical Pharmacology and Physiology and the Harper Cancer Research Institute
| | - Suzanne D Westfall
- Pathology and Anatomical Sciences, University of Missouri, Columbia, Missouri 65212 and
| | - Yueying Liu
- the Harper Cancer Research Institute, Department of Chemistry and Biochemistry, University of Notre Dame, South Bend, Indiana 46617
| | - M Sharon Stack
- the Harper Cancer Research Institute, Department of Chemistry and Biochemistry, University of Notre Dame, South Bend, Indiana 46617
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13
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Poole DP, Lee M, Tso P, Bunnett NW, Yo SJ, Lieu T, Shiu A, Wang JC, Nomura DK, Aponte GW. Feeding-dependent activation of enteric cells and sensory neurons by lymphatic fluid: evidence for a neurolymphocrine system. Am J Physiol Gastrointest Liver Physiol 2014; 306:G686-98. [PMID: 24578341 PMCID: PMC3989702 DOI: 10.1152/ajpgi.00433.2013] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Lymphatic fluid is a plasma filtrate that can be viewed as having biological activity through the passive accumulation of molecules from the interstitial fluid. The possibility that lymphatic fluid is part of an active self-contained signaling process that parallels the endocrine system, through the activation of G-protein coupled receptors (GPCR), has remained unexplored. We show that the GPCR lysophosphatidic acid 5 (LPA5) is found in sensory nerve fibers expressing calcitonin gene-related peptide (CGRP) that innervate the lumen of lymphatic lacteals and enteric nerves. Using LPA5 as a model for nutrient-responsive GPCRs present on sensory nerves, we demonstrate that dietary protein hydrolysate (peptone) can induce c-Fos expression in enterocytes and nerves that express LPA5. Mesenteric lymphatic fluid (MLF) mobilizes intracellular calcium in cell models expressing LPA5 upon feeding in a time- and dose-dependent manner. Primary cultured neurons of the dorsal root ganglia expressing CGRP are activated by MLF, which is enhanced upon LPA5 overexpression. Activation is independent of the known LPA5 agonists, lysophosphatidic acid and farnesyl pyrophosphate. These data bring forth a pathway for the direct stimulation of sensory nerves by luminal contents and interstitial fluid. Thus, by activating LPA5 on sensory nerves, MLF provides a means for known and yet to be identified constituents of the interstitial fluid to act as signals to comprise a "neurolymphocrine" system.
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Affiliation(s)
- Daniel P. Poole
- 1Monash Institute of Pharmaceutical Sciences, Parkville, Victoria, Australia; ,2Department of Anatomy and Neuroscience, The University of Melbourne, Parkville, Victoria, Australia;
| | - Mike Lee
- 4Department of Pathology, Stanford University, Palo Alto, California;
| | - Patrick Tso
- 6Department of Pathobiology and Molecular Medicine, University of Cincinnati, Reading, Ohio
| | - Nigel W. Bunnett
- 1Monash Institute of Pharmaceutical Sciences, Parkville, Victoria, Australia; ,3Department of Pharmacology, The University of Melbourne, Parkville, Victoria, Australia;
| | - Sek Jin Yo
- 5Department of Nutritional Sciences and Toxicology, University of California at Berkeley, Berkeley, California;
| | - TinaMarie Lieu
- 1Monash Institute of Pharmaceutical Sciences, Parkville, Victoria, Australia;
| | - Amy Shiu
- 5Department of Nutritional Sciences and Toxicology, University of California at Berkeley, Berkeley, California;
| | - Jen-Chywan Wang
- 5Department of Nutritional Sciences and Toxicology, University of California at Berkeley, Berkeley, California;
| | - Daniel K. Nomura
- 5Department of Nutritional Sciences and Toxicology, University of California at Berkeley, Berkeley, California;
| | - Gregory W. Aponte
- 5Department of Nutritional Sciences and Toxicology, University of California at Berkeley, Berkeley, California;
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Lysophosphatidic acid increases the electrophysiological instability of adult rabbit ventricular myocardium by augmenting L-type calcium current. PLoS One 2012; 7:e45862. [PMID: 23029283 PMCID: PMC3448719 DOI: 10.1371/journal.pone.0045862] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2012] [Accepted: 08/22/2012] [Indexed: 01/17/2023] Open
Abstract
Lysophosphatidic acid (LPA) has diverse actions on the cardiovascular system and is widely reported to modulate multiple ion currents in some cell types. However, little is known about its electrophysiological effects on cardiac myocytes. This study investigated whether LPA has electrophysiological effects on isolated rabbit myocardial preparations. The results indicate that LPA prolongs action potential duration at 90% repolarization (APD90) in a concentration- and frequency-dependent manner in isolated rabbit ventricular myocytes. The application of extracellular LPA significantly increases the coefficient of APD90 variability. LPA increased L-type calcium current (ICa,L) density without altering its activation or deactivation properties. In contrast, LPA has no effect on two other ventricular repolarizing currents, the transient outward potassium current (Ito) and the delayed rectifier potassium current (IK). In arterially perfused rabbit left ventricular wedge preparations, the monophasic action potential duration, QT interval, and Tpeak-end are prolonged by LPA. LPA treatment also significantly increases the incidence of ventricular tachycardia induced by S1S2 stimulation. Notably, the effects of LPA on action potentials and ICa,L are PTX-sensitive, suggesting LPA action requires a Gi-type G protein. In conclusion, LPA prolongs APD and increases electrophysiological instability in isolated rabbit myocardial preparations by increasing ICa,L in a Gi protein-dependent manner.
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15
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Cyclic regulation of LPA3 in human endometrium. Arch Gynecol Obstet 2012; 287:131-8. [DOI: 10.1007/s00404-012-2479-z] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2012] [Accepted: 07/12/2012] [Indexed: 10/28/2022]
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16
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Castilla-Ortega E, Pedraza C, Chun J, Fonseca FRD, Estivill-Torrús G, Santín LJ. Hippocampal c-Fos activation in normal and LPA1-null mice after two object recognition tasks with different memory demands. Behav Brain Res 2012; 232:400-5. [DOI: 10.1016/j.bbr.2012.04.018] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2012] [Revised: 04/03/2012] [Accepted: 04/10/2012] [Indexed: 12/13/2022]
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17
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Emo J, Meednu N, Chapman TJ, Rezaee F, Balys M, Randall T, Rangasamy T, Georas SN. Lpa2 is a negative regulator of both dendritic cell activation and murine models of allergic lung inflammation. THE JOURNAL OF IMMUNOLOGY 2012; 188:3784-90. [PMID: 22427635 DOI: 10.4049/jimmunol.1102956] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Negative regulation of innate immune responses is essential to prevent excess inflammation and tissue injury and promote homeostasis. Lysophosphatidic acid (LPA) is a pleiotropic lipid that regulates cell growth, migration, and activation and is constitutively produced at low levels in tissues and in serum. Extracellular LPA binds to specific G protein-coupled receptors, whose function in regulating innate or adaptive immune responses remains poorly understood. Of the classical LPA receptors belonging to the Edg family, lpa2 (edg4) is expressed by dendritic cells (DC) and other innate immune cells. In this article, we show that DC from lpa2(-/-) mice are hyperactive compared with their wild-type counterparts and are less susceptible to inhibition by different LPA species. In transient-transfection assays, we found that lpa2 overexpression inhibits NF-κB-driven gene transcription. Using an adoptive-transfer approach, we found that allergen-pulsed lpa2(-/-) DC induced substantially more lung inflammation than did wild-type DC after inhaled allergen challenge. Finally, lpa2(-/-) mice develop greater allergen-driven lung inflammation than do their wild-type counterparts in models of allergic asthma involving both systemic and mucosal sensitization. Taken together, these findings identify LPA acting via lpa2 as a novel negative regulatory pathway that inhibits DC activation and allergic airway inflammation.
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Affiliation(s)
- Jason Emo
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, University of Rochester Medical Center, Rochester, NY 14610, USA
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18
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Abstract
Wnt signalling pathways have been shown to play key roles in both normal development and tumorigenesis. Progression of many human cancers is associated with defined mutations in Wnt pathway components that result in dysregulated β-catenin-mediated gene transcription. Although Wnt pathway mutations are rare in epithelial ovarian cancer (with the exception of the endometrioid histotype), accumulating evidence supports a role for Wnt signalling in ovarian tumorigenesis in the absence of genetic mutations. The present review summarizes evidence in support of activated Wnt signalling in ovarian tumours and discusses alternative mechanisms for Wnt pathway activation in the ovarian tumour microenvironment.
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19
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Zhao J, Chen Q, Li H, Myerburg M, Spannhake EW, Natarajan V, Zhao Y. Lysophosphatidic acid increases soluble ST2 expression in mouse lung and human bronchial epithelial cells. Cell Signal 2011; 24:77-85. [PMID: 21871564 DOI: 10.1016/j.cellsig.2011.08.004] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2011] [Revised: 08/08/2011] [Accepted: 08/09/2011] [Indexed: 12/18/2022]
Abstract
Lysophosphatidic acid (LPA), a naturally occurring bioactive lysophospholipid increases the expression of both pro-inflammatory and anti-inflammatory mediators in airway epithelial cells. Soluble ST2 (sST2), an anti-inflammatory mediator, has been known to function as a decoy receptor of interleukin (IL)-33 and attenuates endotoxin-induced inflammatory responses. Here, we show that LPA increased sST2 mRNA expression and protein release in a dose and time dependent manner in human bronchial epithelial cells (HBEpCs). LPA receptors antagonist and Gαi inhibitor, pertussis toxin, attenuated LPA-induced sST2 release. Inhibition of NF-κB or JNK pathway reduced LPA-induced sST2 release. LPA treatment decreased histone deacetylase 3 (HDAC3) expression and enhanced acetylation of histone H3 at lysine 9 that binds to the sST2 promoter region. Furthermore, limitation of intracellular LPA generation by the down-regulation of acetyl glycerol kinase attenuated exogenous LPA-induced histone H3 acetylation on sST2 promoter region, as well as sST2 gene expression. Treatment of HBEpCs with recombinant sST2 protein or sST2-rich cell culture media attenuated endotoxin-induced phosphorylation of PKC and airway epithelial barrier disruption. These results unravel a novel sST2 mediated signaling pathway that has physiological relevance to airway inflammation and remodeling.
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Affiliation(s)
- Jing Zhao
- Department of Medicine, University of Pittsburgh School of Medicine, Pittsburgh, PA 15213, USA
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20
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Sun Y, Kim NH, Yang H, Kim SH, Huh SO. Lysophosphatidic acid induces neurite retraction in differentiated neuroblastoma cells via GSK-3β activation. Mol Cells 2011; 31:483-9. [PMID: 21499833 PMCID: PMC3887612 DOI: 10.1007/s10059-011-1036-0] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2011] [Accepted: 03/10/2011] [Indexed: 11/27/2022] Open
Abstract
Lysophosphatidic acid (LPA) is a lipid growth factor that exerts diverse biological effects, including rapid neurite retraction and cell migration. Alterations in cell morphology, including neurite retraction, in neurodegenerative disorders such as Alzheimer's disease involve hyperphosphorylation of the cytoskeletal protein tau. Since LPA has been shown to induce neurite retraction in various cultured neural cells and the detailed underlying molecular mechanisms have not yet been elucidated, we investigated whether LPA induced neurite retraction through taumediated signaling pathways in differentiated neuroblastoma cells. When Neuro2a cells differentiated with retinoic acid (RA) were exposed to LPA, cells exhibited neurite retraction in a time-dependent manner. The retraction of neurites was accompanied by the phosphorylation of tau. The LPA-induced neurite retraction and tau phosphorylation in differentiated Neuro2a cells were significantly abolished by the glycogen synthase kinase-3β (GSK-3β) inhibitor lithium chloride. Interestingly, the LPA-stimulated tau phosphorylation and neurite retraction were markedly prevented by the administration of H89, an inhibitor of both cyclic-AMP dependent protein kinase (PKA) and cyclic-AMP response element-binding protein (CREB). Transfection of the dominant-negative CREBs, K-CREB and A-CREB, failed to prevent LPA-induced tau phosphorylation and neurite retraction in differentiated Neuro2a cells. Taken together, these results suggest that GSK-3β and PKA, rather than CREB, play important roles in tau phosphorylation and neurite retraction in LPA-stimulated differentiated Neuro2a cells.
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Affiliation(s)
- Yuanjie Sun
- Department of Pharmacology, College of Medicine, Institute of Natural Medicine, Hallym University, Chunchon 200-702, Korea
- Present address: Chinese Academy of Sciences, Institute of Biophysics, Beijing, 100101, People’s Republic of China
| | - Nam-Ho Kim
- Department of Pharmacology, College of Medicine, Institute of Natural Medicine, Hallym University, Chunchon 200-702, Korea
| | - Haijie Yang
- Department of Pharmacology, College of Medicine, Institute of Natural Medicine, Hallym University, Chunchon 200-702, Korea
| | - Seung-Hyuk Kim
- Department of Pharmacology, College of Medicine, Institute of Natural Medicine, Hallym University, Chunchon 200-702, Korea
| | - Sung-Oh Huh
- Department of Pharmacology, College of Medicine, Institute of Natural Medicine, Hallym University, Chunchon 200-702, Korea
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21
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Pan HL, Zhang YQ, Zhao ZQ. Involvement of lysophosphatidic acid in bone cancer pain by potentiation of TRPV1 via PKCε pathway in dorsal root ganglion neurons. Mol Pain 2010; 6:85. [PMID: 21118579 PMCID: PMC3004845 DOI: 10.1186/1744-8069-6-85] [Citation(s) in RCA: 64] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2010] [Accepted: 12/01/2010] [Indexed: 12/24/2022] Open
Abstract
Background It has been demonstrated that lysophosphatidic acid (LPA) released from injury tissue and transient receptor potential vanilloid 1 (TRPV1) receptor are implicated in the induction of chronic pain. In the present study we examined whether an interaction between LPA receptor LPA1 and TRPV1 in dorsal root ganglion (DRG) neurons contributes to the development of bone cancer pain. Results Bone cancer was established by injection of mammary gland carcinoma cells into the rat tibia. Following the development of bone cancer pain, the TRPV1 expression and capsaicin-evoked currents were up-regulated in rat DRG neurons at L4-6 segments. Immunohistochemistry staining revealed a high co-localization of LPA1 with TRPV1 in DRG neurons. In isolated DRG neurons, whole-cell patch recording showed that capsaicin-induced currents were potentiated by LPA in a dose-dependent manner. The potentiation was blocked by either LPA1 antagonist, protein kinase C (PKC) inhibitor or PKCϵ inhibitor, but not by protein kinase A (PKA) inhibitor or Rho inhibitor. In the behavioral tests, both mechanical allodynia and thermal hyperalgesia in bone cancer rats were attenuated by LPA1 antagonist. Conclusion LPA potentiates TRPV1 current via a PKCϵ-dependent pathway in DRG neurons of rats with bone cancer, which may be a novel peripheral mechanism underlying the induction of bone cancer pain.
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Affiliation(s)
- Hai-Li Pan
- Institute of Neurobiology, Institutes of Brain Science and State Key Laboratory of Medical Neurobiology, Fudan University, Shanghai 200032, China
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22
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Lysophosphatidic Acid Upregulates Laminin-332 Expression during A431 Cell Colony Dispersal. JOURNAL OF ONCOLOGY 2010; 2010. [PMID: 20862207 PMCID: PMC2938436 DOI: 10.1155/2010/107075] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/16/2010] [Revised: 06/11/2010] [Accepted: 07/02/2010] [Indexed: 01/01/2023]
Abstract
Lysophosphatidic acid (LPA) is a bioactive phospholipid that affects various biological functions, such as cell proliferation, migration, survival, wound healing, and tumor invasion through LPA receptors. Previously, we reported that LPA induces A431 colony dispersal, accompanied by disruption of cell-cell contacts and cell migration. However, it remains unclear how LPA affects cell migration and gene expression during A431 colony dispersal. In this paper, we performed cDNA microarray analysis to investigate this question by comparing gene expression between untreated and LPA-treated A431 cells. Interestingly, these results revealed that LPA treatment upregulates several TGF-β1 target genes, including laminin-332 (Ln-332) components (α3, β3, and γ2 chains). Western blot analysis also showed that LPA increased phosphorylation of Smad2, an event that is carried out by TGF-β1 interactions. Among the genes upregulated, we further addressed the role of Ln-332. Real-time PCR analysis confirmed the transcriptional upregulation of all α3, β3, and γ2 chains of Ln-332 by LPA, corresponding to the protein level increases revealed by western blot. Further, the addition of anti-Ln-332 antibody prevented LPA-treated A431 colonies from dispersing. Taken together, our results suggest that LPA-induced Ln-332 plays a significant role in migration of individual cells from A431 colonies.
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23
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Kumar SA, Hu X, Brown M, Kuschak B, Hernandez TA, Johnston JB, Gibson SB. Lysophosphatidic acid receptor expression in chronic lymphocytic leukemia leads to cell survival mediated though vascular endothelial growth factor expression. Leuk Lymphoma 2010; 50:2038-48. [PMID: 19860625 DOI: 10.3109/10428190903275586] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Lysophosphatidic acid (LPA) protects chronic lymphocytic leukemia (CLL) cells from apoptosis. Vascular endothelial growth factor (VEGF) also protects CLL cells against apoptosis. The mechanism for LPA protection against apoptosis in CLL cells is unknown. Herein, we show CLL cells express LPA receptors LPA(1-5) but in normal B cells, LPA(1) was rarely expressed and LPA(3,) LPA(4,) and LPA(6) were undetectable whereas the other LPA receptors were expressed. LPA plasma levels are similar in patients with CLL compared to healthy controls. In contrast, plasma levels of VEGF are elevated in patients with CLL compared to healthy controls and LPA treatment induced VEGF secretion in CLL cells. CLL cells also express VEGF receptors and LPA protection against Flu induced apoptosis is blocked by inhibition of VEGF receptor activation. These results indicate that LPA protects CLL cells from apoptosis through higher expression of LPA receptors and autocrine production of VEGF.
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Trimbuch T, Beed P, Vogt J, Schuchmann S, Maier N, Kintscher M, Breustedt J, Schuelke M, Streu N, Kieselmann O, Brunk I, Laube G, Strauss U, Battefeld A, Wende H, Birchmeier C, Wiese S, Sendtner M, Kawabe H, Kishimoto-Suga M, Brose N, Baumgart J, Geist B, Aoki J, Savaskan NE, Bräuer AU, Chun J, Ninnemann O, Schmitz D, Nitsch R. Synaptic PRG-1 modulates excitatory transmission via lipid phosphate-mediated signaling. Cell 2009; 138:1222-35. [PMID: 19766573 DOI: 10.1016/j.cell.2009.06.050] [Citation(s) in RCA: 107] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2008] [Revised: 04/30/2009] [Accepted: 06/19/2009] [Indexed: 11/27/2022]
Abstract
Plasticity related gene-1 (PRG-1) is a brain-specific membrane protein related to lipid phosphate phosphatases, which acts in the hippocampus specifically at the excitatory synapse terminating on glutamatergic neurons. Deletion of prg-1 in mice leads to epileptic seizures and augmentation of EPSCs, but not IPSCs. In utero electroporation of PRG-1 into deficient animals revealed that PRG-1 modulates excitation at the synaptic junction. Mutation of the extracellular domain of PRG-1 crucial for its interaction with lysophosphatidic acid (LPA) abolished the ability to prevent hyperexcitability. As LPA application in vitro induced hyperexcitability in wild-type but not in LPA(2) receptor-deficient animals, and uptake of phospholipids is reduced in PRG-1-deficient neurons, we assessed PRG-1/LPA(2) receptor-deficient animals, and found that the pathophysiology observed in the PRG-1-deficient mice was fully reverted. Thus, we propose PRG-1 as an important player in the modulatory control of hippocampal excitability dependent on presynaptic LPA(2) receptor signaling.
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Affiliation(s)
- Thorsten Trimbuch
- Institute of Cell Biology and Neurobiology and NeuroCure, Charité, Universitätsmedizin Berlin, Berlin, Germany
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Kwon YJ, Sun Y, Kim NH, Huh SO. Phosphorylation of CREB, a cyclic AMP responsive element binding protein, contributes partially to lysophosphatidic acid-induced fibroblast cell proliferation. Biochem Biophys Res Commun 2009; 380:655-9. [PMID: 19285017 DOI: 10.1016/j.bbrc.2009.01.159] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2008] [Accepted: 01/26/2009] [Indexed: 10/21/2022]
Abstract
Lysophospholipids regulate a wide array of biological processes including cell survival and proliferation. In our previous studies, we found that in addition to SRE, CRE is required for maximal c-fos promoter activation triggered by lysophosphatidic acid (LPA). c-fos is an early indicator of various cells into the cell cycle after mitogenic stimulation. However, role of CREB activation in LPA-stimulated proliferation has not been elucidated yet. Here, we investigate how LPA induces proliferation in Rat-2 fibroblast cell via CREB activation. We found that total cell number and BrdU-positive cells were increased by LPA. Moreover, levels of c-fos mRNA and cyclin D1 protein were increased via LPA-induced CREB phosphorylation. Furthermore, LPA-induced Rat-2 cell proliferation was decreased markedly by ERK inhibitor (U0126) and partially by MSK inhibitor (H89). Taken together, these results suggest that CREB activation could partially up-regulate accumulation of cyclin D1 protein level and proliferation of LPA-stimulated Rat-2 fibroblast cells.
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Affiliation(s)
- Yong-Jun Kwon
- Department of Pharmacology, College of Medicine, Institute of Natural Medicine, Hallym University, Chunchon, Gangwon-do 200-702, South Korea
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26
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Zhao Y, Natarajan V. Lysophosphatidic acid signaling in airway epithelium: role in airway inflammation and remodeling. Cell Signal 2009; 21:367-77. [PMID: 18996473 PMCID: PMC2660380 DOI: 10.1016/j.cellsig.2008.10.010] [Citation(s) in RCA: 61] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2008] [Revised: 09/27/2008] [Accepted: 10/21/2008] [Indexed: 02/07/2023]
Abstract
Lysophosphatidic acid (LPA), a potent bioactive phospholipid, induces diverse cellular responses, including cell proliferation, migration, and cytokine release. LPA can be generated intracellularly and extracellularly through multiple synthetic pathways by action of various enzymes, such as phospholipase A(1/2) (PLA(1/2)), phospholipase D (PLD), acylglycerol kinase (AGK), and lysophospholipase D (lysoPLD). Metabolism of LPA is regulated by a family of lipid phosphate phosphatases (LPPs). Significant amounts of LPA have been detected in various biological fluids, including serum, saliva, and bronchoalveolar lavage fluid (BALF). The most significant effects of LPA appear to be through activation of the G-protein-coupled receptors (GPCRs), termed LPA(1-6). LPA regulates gene expression through activation of several transcriptional factors, such as nuclear factor-kappaB (NF-kappaB), AP-1, and C/EBPbeta. In addition to GPCRs, cross-talk between LPA receptors and receptor tyrosine kinases (RTKs) partly regulates LPA-induced intracellular signaling and cellular responses. Airway epithelial cells participate in innate immunity through the release of cytokines, chemokines, lipid mediators, other inflammatory mediators and an increase in barrier function in response to a variety of inhaled stimuli. Expression of LPA receptors has been demonstrated in airway epithelial cells. This review summarizes our recent observations of the role of LPA/LPA-Rs in regulation of airway epithelium, especially in relation to the secretion of pro- and anti-inflammatory mediators and regulation of airway barrier function.
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Affiliation(s)
- Yutong Zhao
- Department of Medicine, University of Chicago, Chicago, IL 60637, USA.
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27
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Abstract
Lysophosphatidic acid (LPA) can affect the growth, migration, and activation of many different cell types. Research in this field has recently accelerated due to the molecular cloning of LPA receptors as well as advances in our understanding of LPA metabolism. A major pathway for LPA generation is the hydrolysis of lysophosphatidylcholine by the enzyme autotaxin (ATX). Although most research to-date has been conducted in other disciplines (e.g., neurobiology and cardiovascular diseases), emerging data point to an important role for LPA and ATX in regulating immune responses. Here we review current understanding of LPA and ATX in immunity with an emphasis on migration and activation of lymphocytes and dendritic cells. New gene-targeted and transgenic mice, receptor-specific antibodies, and pathway antagonists should rapidly enhance our understanding of this versatile lysolipid in immune responses in the near future.
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Affiliation(s)
- Steve N Georas
- Division of Pulmonary and Critical Care Medicine, University of Rochester Medical Center, NY 14610, USA.
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Fujiwara Y. Cyclic phosphatidic acid - a unique bioactive phospholipid. BIOCHIMICA ET BIOPHYSICA ACTA 2008; 1781:519-24. [PMID: 18554524 PMCID: PMC2572151 DOI: 10.1016/j.bbalip.2008.05.002] [Citation(s) in RCA: 56] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/29/2008] [Revised: 05/06/2008] [Accepted: 05/12/2008] [Indexed: 02/05/2023]
Abstract
Cyclic phosphatidic acid (CPA) is a naturally occurring analog of the growth factor-like phospholipid mediator, lysophosphatidic acid (LPA). The sn-2 hydroxy group of CPA forms a 5-membered ring with the sn-3 phosphate. CPA affects numerous cellular functions, including anti-mitogenic regulation of the cell cycle, induction of stress fiber formation, inhibition of tumor cell invasion and metastasis, and regulation of differentiation and survival of neuronal cells. Interestingly, many of these cellular responses caused by CPA oppose those of LPA despite the activation of apparently overlapping receptor populations. Since the early 1990s, studies on CPA actions gradually developed, and we are now beginning to understand the importance of this lipid. In this review, we focus on the current knowledge about CPA, including enzymatic formation of CPA, unique biological activities and biological targets of CPA, and we also explore metabolically stabilized CPA analogs.
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Affiliation(s)
- Yuko Fujiwara
- Department of Physiology, The University of Tennessee Health Sciences Center, 894 Union Avenue, Memphis, TN 38163, USA.
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29
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Chen J, Chen Y, Zhu W, Han Y, Han B, Xu R, Deng L, Cai Y, Cong X, Yang Y, Hu S, Chen X. Specific LPA receptor subtype mediation of LPA-induced hypertrophy of cardiac myocytes and involvement of Akt and NFkappaB signal pathways. J Cell Biochem 2008; 103:1718-31. [PMID: 17891781 DOI: 10.1002/jcb.21564] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Lysophosphatidic acid (LPA) is a bioactive phospholipid with diverse functions mediated via G-protein-coupled receptors (GPCRs). In view of the elevated levels of LPA in acute myocardial infarction (MI) patients we have conducted studies aimed at identifying specific LPA receptor subtypes and signaling events that may mediate its actions in hypertrophic remodeling. Experiments were carried out in cultured neonatal rat cardiomyocytes (NRCMs) exposed to LPA and in a rat MI model. In NRCMs, LPA-induced hypertrophic growth was completely abrogated by DGPP, an LPA1/LPA3 antagonist. The LPA3 agonist OMPT, but not the LPA2 agonist dodecylphosphate, promoted hypertrophy as examined by 3[H]-Leucine incorporation, ANF-luciferase expression and cell area. In in vivo experiments, LPA1, LPA2 and LPA3 mRNA levels as well as LPA1 and LPA3 protein levels increased together with left ventricular remodeling (LVRM) after MI. In addition, LPA stimulated the phosphorylation of Akt and p65 protein and activated NF-kappaB-luciferase expression. Inhibitors of PI3K (wortmannin), mTOR (rapamycin), and NF-kappaB (PDTC or SN50) effectively prevented LPA-induced 3[H]-Leucine incorporation and ANF-luciferase expression. Furthermore, ERK inhibitors (U0126 and PD98059) suppressed LPA-stimulated activation of NF-kappaB and p65 phosphorylation whereas wortmannin showed no effect on NF-kappaB activation. Our findings indicate that LPA3 and/or LPA1 mediate LPA-induced hypertrophy of NRCMs and that LPA1 and LPA3 may be involved in LVRM of MI rats. Moreover, Akt and NF-kappaB signaling pathways independently implicate in LPA-stimulated myocardial hypertrophic growth.
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Affiliation(s)
- Jinghai Chen
- Research Center for Cardiovascular Regenerative Medicine, the Ministry of Health, Cardiovascular Institute and Fuwai Hospital, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, China
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Rhim JH, Jang IS, Song KY, Ha MK, Cho SC, Yeo EJ, Park SC. Lysophosphatidic Acid and Adenylyl Cyclase Inhibitor Increase Proliferation of Senescent Human Diploid Fibroblasts by Inhibiting Adenosine Monophosphate-Activated Protein Kinase. Rejuvenation Res 2008; 11:781-92. [DOI: 10.1089/rej.2008.0709] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Affiliation(s)
- Ji-Heon Rhim
- Department of Biochemistry and Molecular Biology, Aging and Apoptosis Research Center, Seoul National University College of Medicine, Seoul, South Korea
| | - Ik-Soon Jang
- Korea Basic Science Institute Gwangju Center, Gwangju, South Korea
| | - Kye-Yong Song
- Department of Pathology, Chung-Ang University College of Medicine, Seoul, South Korea
| | - Moon-Kyung Ha
- Department of Biochemistry and Molecular Biology, Aging and Apoptosis Research Center, Seoul National University College of Medicine, Seoul, South Korea
| | - Sung-Chun Cho
- Department of Biochemistry and Molecular Biology, Aging and Apoptosis Research Center, Seoul National University College of Medicine, Seoul, South Korea
| | - Eui-Ju Yeo
- Department of Biochemistry, Gachon University of Medicine and Science, Incheon, South Korea
| | - Sang Chul Park
- Department of Biochemistry and Molecular Biology, Aging and Apoptosis Research Center, Seoul National University College of Medicine, Seoul, South Korea
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Fujita R, Ma Y, Ueda H. Lysophosphatidic acid-induced membrane ruffling and brain-derived neurotrophic factor gene expression are mediated by ATP release in primary microglia. J Neurochem 2008; 107:152-60. [PMID: 18680554 DOI: 10.1111/j.1471-4159.2008.05599.x] [Citation(s) in RCA: 59] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
We examined the effects of lysophosphatidic acid (LPA) on microglia, which may play an important role in the development and maintenance of neuropathic pain. LPA caused membrane ruffling as detected by scanning electron microscopy, and increased the expression of brain-derived neurotrophic factor (BDNF) in a primary culture of rat microglia, which express LPA(3), but not LPA(1) or LPA(2) receptors. These actions were inhibited by a Galpha(q/11)-antisense oligodeoxynucleotide (AS-ODN), U73122, an inhibitor of phospholipase C (PLC), and apyrase, which specifically degrades ATP and ADP. When ATP release was measured using a luciferin-luciferase bioluminescence assay, LPA was shown to increase it in an LPA(3) and PLC inhibitor-reversible manner. However, LPA-induced ATP release was also blocked by the Galpha(q/11) AS-ODN, but not by pertussis toxin. These results suggest that LPA induces the release of ATP from rat primary cultured microglia via the LPA(3) receptor, Galpha(q/11) and PLC, and that the released ATP or ectopically converted ADP may in turn cause membrane ruffling via P2Y(12) receptors and Galpha(i/o) activation, and BDNF expression via activation of P2X(4) receptors.
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Affiliation(s)
- Ryousuke Fujita
- Division of Molecular Pharmacology and Neuroscience, Nagasaki University Graduate School of Biomedical Sciences, Bunkyo-machi, Nagasaki, Japan
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32
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Jo SH, Kim SD, Kim JM, Lee HY, Lee SY, Shim JW, Yun J, Im DS, Bae YS. Lysophosphatidylglycerol stimulates chemotactic migration in human natural killer cells. Biochem Biophys Res Commun 2008; 372:147-51. [DOI: 10.1016/j.bbrc.2008.05.004] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2008] [Accepted: 05/01/2008] [Indexed: 01/19/2023]
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33
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Ovarian cancer immuno-reactive antigen domain containing 1 (OCIAD1), a key player in ovarian cancer cell adhesion. Gynecol Oncol 2008; 109:226-33. [DOI: 10.1016/j.ygyno.2007.12.024] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2007] [Revised: 12/12/2007] [Accepted: 12/18/2007] [Indexed: 11/22/2022]
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34
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Fells JI, Tsukahara R, Fujiwara Y, Liu J, Perygin DH, Osborne DA, Tigyi G, Parrill AL. Identification of non-lipid LPA3 antagonists by virtual screening. Bioorg Med Chem 2008; 16:6207-17. [PMID: 18467108 DOI: 10.1016/j.bmc.2008.04.035] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2008] [Revised: 04/15/2008] [Accepted: 04/16/2008] [Indexed: 10/22/2022]
Abstract
In the present study, we utilized virtual screening to identify LPA(3) antagonists. We have developed a three-point structure-based pharmacophore model based on known LPA(3) antagonists. This model was used to mine the NCI database. Docking, pharmacophore development, and database mining produced new, non-lipid leads. Experimental testing of seven computationally selected pharmacophore hits produced one potentiator and three antagonists, one of which displays both LPA(3) selectivity and nanomolar potency. Similarity searching in the ChemBridge database using the most promising lead as the search target produced four additional LPA(3) antagonists and a potent dual LPA(1&2) antagonist.
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Affiliation(s)
- James I Fells
- Department of Chemistry and Computational Research on Materials Institute, The University of Memphis, Memphis, TN 38152, USA
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35
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Endogenous RGS proteins attenuate Galpha(i)-mediated lysophosphatidic acid signaling pathways in ovarian cancer cells. Cell Signal 2007; 20:381-9. [PMID: 18083345 DOI: 10.1016/j.cellsig.2007.10.026] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2007] [Accepted: 10/30/2007] [Indexed: 01/06/2023]
Abstract
Lysophosphatidic acid is a bioactive phospholipid that is produced by and stimulates ovarian cancer cells, promoting proliferation, migration, invasion, and survival. Effects of LPA are mediated by cell surface G-protein coupled receptors (GPCRs) that activate multiple heterotrimeric G-proteins. G-proteins are deactivated by Regulator of G-protein Signaling (RGS) proteins. This led us to hypothesize that RGS proteins may regulate G-protein signaling pathways initiated by LPA in ovarian cancer cells. To determine the effect of endogenous RGS proteins on LPA signaling in ovarian cancer cells, we compared LPA activity in SKOV-3 ovarian cancer cells expressing G(i) subunit constructs that are either insensitive to RGS protein regulation (RGSi) or their RGS wild-type (RGSwt) counterparts. Both forms of the G-protein contained a point mutation rendering them insensitive to inhibition with pertussis toxin, and cells were treated with pertussis toxin prior to experiments to eliminate endogenous G(i/o) signaling. The potency and efficacy of LPA-mediated inhibition of forskolin-stimulated adenylyl cyclase activity was enhanced in cells expressing RGSi G(i) proteins as compared to RGSwt G(i). We further showed that LPA signaling that is subject to RGS regulation terminates much faster than signaling thru RGS insensitive G-proteins. Finally, LPA-stimulated SKOV-3 cell migration, as measured in a wound-induced migration assay, was enhanced in cells expressing Galpha(i2) RGSi as compared to cells expressing Galpha(i2) RGSwt, suggesting that endogenous RGS proteins in ovarian cancer cells normally attenuate this LPA effect. These data establish RGS proteins as novel regulators of LPA signaling in ovarian cancer cells.
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36
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Lee SY, Lee HY, Kim SD, Shim JW, Bae YS. Lysophosphatidylglycerol stimulates chemotactic migration and tube formation in human umbilical vein endothelial cells. Biochem Biophys Res Commun 2007; 363:490-4. [PMID: 17888875 DOI: 10.1016/j.bbrc.2007.08.194] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2007] [Accepted: 08/25/2007] [Indexed: 11/16/2022]
Abstract
In this study, we observed that lysophosphatidylglycerol (LPG) stimulates extracellular signal-regulated kinase (ERK) in human umbilical vein endothelial cells (HUVECs). LPG-stimulated ERK activity was not inhibited by pertussis toxin (PTX), indicating PTX-sensitive G-proteins-independent manner. In terms of functional aspect, LPG induced chemotactic migration of HUVECs in a PTX-insensitive manner. Preincubation of HUVECs with an ERK inhibitor (PD98059) completely inhibited LPG-induced chemotactic migration, suggesting the crucial role of ERK in the process. LPG-induced ERK activation and chemotactic migration in HUVECs were not affected by an lysophosphatidic acid receptor-selective antagonist (Ki16425), indicating lysophosphatidic acid receptors-independency. We also found that LPG stimulated tube formation in HUVECs. Taken together we suggest that LPG stimulates HUVECs and result in chemotactic migration and tube formation, suggesting a new aspect of LPG as a modulator of endothelial cell functioning.
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Affiliation(s)
- Sun Young Lee
- Department of Biochemistry, College of Medicine, Dong-A University, Busan 602-714, Republic of Korea
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37
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Georas SN, Berdyshev E, Hubbard W, Gorshkova IA, Usatyuk PV, Saatian B, Myers AC, Williams MA, Xiao HQ, Liu M, Natarajan V. Lysophosphatidic acid is detectable in human bronchoalveolar lavage fluids at baseline and increased after segmental allergen challenge. Clin Exp Allergy 2007; 37:311-22. [PMID: 17359381 DOI: 10.1111/j.1365-2222.2006.02626.x] [Citation(s) in RCA: 81] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
BACKGROUND Lysophosphatidic acid (LPA) is a biologically active lysophospholipid and a component of normal plasma. LPA binds to receptors expressed on circulating and structural lung cells and affects cell growth and activation. Whether LPA is present in the lung has not been previously reported. OBJECTIVE To develop an assay to measure LPA in bronchoalveolar lavage (BAL) fluids, and to study the association between LPA and allergic airway inflammation. METHODS Seventeen allergic subjects underwent bronchoscopy and segmental allergen challenge, followed 18 h later by BAL. Supernatants were analysed for LPA content using liquid chromatography and mass spectroscopy. Expression of LPA receptors on primary bronchial epithelial cells was analysed by immunolabelling, and the effects of LPA on epithelial cell barrier function was investigated by measuring transepithelial resistance. RESULTS LPA was detectable in BAL from control lung segments, and significantly increased 18 h after allergen challenge. Polyunsaturated species of LPA were especially increased following segmental allergen challenge. LPA levels did not strongly correlate with the number or percentages of eosinophils, neutrophils of lymphocytes, whereas MIP-3alpha (CCL20) levels correlated significantly with the allergen-driven influx of lymphocytes. The levels of LPA from control sites correlated inversely with BAL protein content, suggesting that LPA promoted epithelial barrier integrity at baseline. Experiments using primary human bronchial epithelial cells confirmed that LPA tightened the epithelial cell barrier. CONCLUSION Lysophosphatidic acid is detectable in human BAL fluids at baseline and its expression increases during allergic inflammation. LPA does not appear to be a dominant chemoattractant for eosinophils or lymphocytes during allergic airway inflammation. In the absence of ongoing inflammation, LPA may promote epithelial barrier integrity.
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Affiliation(s)
- S N Georas
- Division of Pulmonary & Critical Care Medicine, The Johns Hopkins Asthma & Allergy Center, Baltimore, MD, USA.
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38
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D'Aquilio F, Procaccini M, Izzi V, Chiurchiu' V, Giambra V, Carotenuto F, Di Nardo P, Baldini PM. Activatory Properties of Lysophosphatidic Acid on Human THP-1 Cells. Inflammation 2007; 30:167-77. [PMID: 17594136 DOI: 10.1007/s10753-007-9034-2] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
Excessive leukocyte proliferation and proinflammatory mediators release represent common phenomena in several chronic inflammatory diseases. Multiple evidences identify lysophosphatidic acid (LPA), a small lipid endowed with pleiotropic activities, as an important modulator of both proliferation and activation of different cell types involved in several inflammation-associated pathologies. However, its possible role on monocyte proinflammatory activation is not fully understood yet. Aim of the present study was to investigate LPA effects on THP-1 cells in terms of proliferation, reactive oxygen intermediates (ROI) production and release of arachidonic acid-derived inflammatory mediators. Actually, LPA significantly increased both DNA synthesis and ROI production as well as prostaglandin E(2) release and the upregulation of LPA(3) receptor expression. These findings identified LPA as both a growth factor and a triggering mediator of proinflammatory response in THP-1 cells.
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Affiliation(s)
- F D'Aquilio
- Department of Biology, University of Rome Tor Vergata, Via della Ricerca Scientifica, 00133, Rome, Italy
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39
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Salcedo M, Cuevas C, Alonso JL, Otero G, Faircloth G, Fernandez-Sousa JM, Avila J, Wandosell F. The marine sphingolipid-derived compound ES 285 triggers an atypical cell death pathway. Apoptosis 2007; 12:395-409. [PMID: 17191124 DOI: 10.1007/s10495-006-0573-z] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
The isolation of new molecules from marine sources opens the door to their possible therapeutic use against tumors and other pathological conditions. Indeed, we recently defined the cytotoxicity of ES 285, obtained from the clam Mactromeris polynima, and its affects on the cells microfilament but not the microtubule network. Considering the analogy between ES 285 and sphingosine-related lipids, we wondered whether ES 285 might affect the activity of PKC at the intracellular level. While we anticipated that ES 285 might inhibit PKC, it turns out that in contrast it serves to activate PKC at the cellular level. Indeed, like other sphingosine-related lipids, ES 285 induces the phosphorylation of MARCKS. Additionally, we further examined the cytotoxicity of ES 285 to elucidate the molecular mechanisms through which this compound triggers apoptosis. When the influence of ES 285 on "cell death markers" was assessed, it became clear that ES285 activates caspase 3 and 12, and that it modified the phosphorylation of p53. In contrast, ES 285 does not affect other pathways widely implicated in regulating cell survival/apoptosis, such as JNK, Erks or Akt. Thus, these data suggest that ES 285-triggers an atypical cell death program when compared to other sphingosine-dependent apoptosis pathways.
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Affiliation(s)
- M Salcedo
- Centro de Biología Molecular Severo Ochoa, Facultad de Ciencias, Universidad Autónoma de Madrid, 28049, Madrid, Spain
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40
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Chen R, Roman J, Guo J, West E, McDyer J, Williams MA, Georas SN. Lysophosphatidic acid modulates the activation of human monocyte-derived dendritic cells. Stem Cells Dev 2007; 15:797-804. [PMID: 17253943 DOI: 10.1089/scd.2006.15.797] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Lysophosphatidic acid (LPA) is a biologically active lysophospholipid that can regulate immune activation. LPA can activate T cells and dendritic cells (DCs), but the effects of LPA on the ability of DCs to influence T cell polarization are not well understood. Human monocyte-derived DCs were differentiated in vitro in the presence of interleukin-4 (IL-4) and granulocyte-macrophage colonystimulating factor (GM-CSF), and matured with LPA and lipopolysaccharide (LPS) alone or in combination. DC activation was monitored by analyzing cell-surface expression of co-stimulatory receptors and cytokine production. The ability of DCs to influence T cell activation was determined using two models of DC:T cell co-culture. Maturation with LPS induced dose-dependent DC activation characterized by enhanced expression of co-stimulatory molecules (e.g., CD86) and production of cytokines including IL-6 and IL-10. Co-incubation with LPA attenuated the LPS-induced production of IL-6, without significantly affecting IL-10 secretion or the ability of DC to promote T cell proliferation. DCs matured in the presence of both LPA and LPS enhanced the production of interferon-gamma (IFN-gamma) when co-cultured with allogeneic T cells, compared with DC matured by LPS alone. Similar results were found using a model of allogeneic naïve T cell differentiation, where LPA- plus LPS-matured DC enhanced IFN-gamma as well as IL-4 secretion after restimulation. Lysophosphatidic acid fine-tunes the effects of LPS on human myeloid DC maturation, but does not exert a dominant effect on the ability of DC to influence Th cell polarization.
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Affiliation(s)
- Rongbing Chen
- Division of Pulmonary & Critical Care Medicine, Johns Hopkins Asthma and Allergy Center, Baltimore, MD 21212, USA
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41
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Pyne NJ, Waters CM, Long JS, Moughal NA, Tigyi G, Pyne S. Receptor tyrosine kinase-G-protein coupled receptor complex signaling in mammalian cells. ACTA ACUST UNITED AC 2007; 47:271-80. [PMID: 17337042 PMCID: PMC3446785 DOI: 10.1016/j.advenzreg.2006.12.011] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Nigel J. Pyne
- Department of Physiology and Pharmacology, Strathclyde Institute for Biomedical Sciences, University of Strathclyde, 27 Taylor St, Glasgow G4 0NR, UK
- Corresponding author. (N.J. Pyne)
| | - Catherine M. Waters
- Department of Physiology and Pharmacology, Strathclyde Institute for Biomedical Sciences, University of Strathclyde, 27 Taylor St, Glasgow G4 0NR, UK
| | - Jaclyn S. Long
- Department of Physiology and Pharmacology, Strathclyde Institute for Biomedical Sciences, University of Strathclyde, 27 Taylor St, Glasgow G4 0NR, UK
| | | | - Gabor Tigyi
- Department of Physiology, University of Tennessee Health Science Center Memphis, 894 Union Avenue, Memphis, USA
| | - Susan Pyne
- Department of Physiology and Pharmacology, Strathclyde Institute for Biomedical Sciences, University of Strathclyde, 27 Taylor St, Glasgow G4 0NR, UK
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42
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Zhao Y, He D, Zhao J, Wang L, Leff AR, Spannhake EW, Georas S, Natarajan V. Lysophosphatidic acid induces interleukin-13 (IL-13) receptor alpha2 expression and inhibits IL-13 signaling in primary human bronchial epithelial cells. J Biol Chem 2007; 282:10172-9. [PMID: 17287216 PMCID: PMC2659592 DOI: 10.1074/jbc.m611210200] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Interleukin-13 (IL-13), a Th2 cytokine, plays a pivotal role in pathogenesis of bronchial asthma via IL-13 receptor alpha1 (IL-13Ralpha1) and IL-4 receptor alpha (IL-4Ralpha). Recent studies show that a decoy receptor for IL-13, namely IL-13Ralpha2, mitigates IL-13 signaling and function. This study provides evidence for regulation of IL-13Ralpha2 production and release and IL-13-dependent signaling by lysophosphatidic acid (LPA) in primary cultures of human bronchial epithelial cells (HBEpCs). LPA treatment of HBEpCs in at imedependent fashion increased IL-13Ralpha2 gene expression without altering the mRNA levels of IL-13Ralpha1 and IL-4Ralpha. Pretreatment with pertussis toxin (100 ng/ml, 4 h) or transfection of c-Jun small interference RNA or an inhibitor of JNK attenuated LPA-induced IL-13Ralpha2 gene expression and secretion of soluble IL-13Ralpha2. Overexpression of catalytically inactive mutants of phospholipase D (PLD) 1 or 2 attenuated LPA-induced IL-13Ralpha2 gene expression and protein secretion as well as phosphorylation of JNK. Pretreatment of HBEpCs with 1 microM LPA for 6 h attenuated IL-13-but not IL-4-induced phosphorylation of STAT6. Transfection of HBEpCs with IL-13Ralpha2 small interference RNA blocked the effect of LPA on IL-13-induced phosphorylation of STAT6. Furthermore, pretreatment with LPA (1 microM, 6 h) attenuated IL-13-induced eotaxin-1 and SOCS-1 gene expression. These results demonstrate that LPA induces IL-13Ralpha2 expression and release via PLD and JNK/AP-1 signal transduction and that pretreatment with LPA down-regulates IL-13 signaling in HBEpCs. Our data suggest a novel mechanism of regulation of IL-13Ralpha2 and IL-13 signaling that may be of physiological relevance to airway inflammation and remodeling.
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Affiliation(s)
- Yutong Zhao
- Section of Pulmonary and Critical Care, Department of Medicine, University of Chicago, Chicago, Illinois 60637, USA.
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43
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Rhim JH, Jang IS, Yeo EJ, Song KY, Park SC. Role of protein kinase C-dependent A-kinase anchoring proteins in lysophosphatidic acid-induced cAMP signaling in human diploid fibroblasts. Aging Cell 2006; 5:451-61. [PMID: 17081159 DOI: 10.1111/j.1474-9726.2006.00239.x] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
Abstract
Previously, we reported that lysophosphatidic acid (LPA)-induced adenosine 3',5'-cyclic monophosphate (cAMP) production by human diploid fibroblasts depends on the age of the fibroblasts. In this study, we examined the role of A-kinase anchoring proteins (AKAP) in the regulation of LPA-stimulated cAMP production in senescent fibroblasts. We found that levels of protein kinase C (PKC)-dependent AKAPs, such as Gravin and AKAP79, were elevated in senescent cells. Co-immunoprecipitation experiments revealed that Gravin and AKAP79 do not associate with adenylyl cyclase type 2 (AC2) but bind to AC4/6, which interacts with calcium-dependent PKCs alpha/beta both in young and senescent fibroblasts. When the expression of Gravin and AKAP79 was blocked by small interference RNA transfection, the basal level of cAMP was greatly reduced and the cAMP status after LPA treatment was also reversed. Protein kinase A showed a similar pattern in terms of its basal activity and LPA-dependent modulation. These data suggest that Gravin and to a lesser extent, AKAP79, may play important roles in maintaining the basal AC activity and in coupling the AC systems to inhibitory signals such as Gialpha in young cells, and to stimulatory signals such as PKCs in senescent cells. This study also demonstrates that Gravin is especially important for the long-term activation of PKC by LPA in senescent cells. We conclude that LPA-dependent increased level of cAMP in senescent human diploid fibroblasts is associated with increases in Gravin levels resulting in its increased binding with and activation of calcium-dependent PKC alpha/beta and AC4/6.
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Affiliation(s)
- Ji-Heon Rhim
- Department of Biochemistry and Molecular Biology, Aging and Apoptosis Research Center, Seoul National University College of Medicine, Seoul 110-799, South Korea
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44
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D'Aquilio F, Procaccini M, Izzi V, Chiurchiu' V, Giambra V, Carotenuto F, Di Nardo P, Baldini PM. Activatory properties of lysophosphatidic acid on human THP-1 cells. Inflammation 2006; 29:129-40. [PMID: 17089191 DOI: 10.1007/s10753-006-9008-9] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2006] [Accepted: 07/27/2006] [Indexed: 02/07/2023]
Abstract
Excessive leukocyte proliferation and proinflammatory mediators release represent common phenomena in several chronic inflammatory diseases. Multiple evidences identify lysophosphatidic acid (LPA), a small lipid endowed with pleiotropic activities, as an important modulator of both proliferation and activation of different cell types involved in several inflammation-associated pathologies. However, its possible role on monocyte proinflammatory activation is not fully understood yet. Aim of the present study was to investigate LPA effects on THP-1 cells in terms of proliferation, reactive oxygen intermediates (ROI) production and release of arachidonic acid-derived inflammatory mediators. Actually, LPA significantly increased both DNA synthesis and ROI production as well as prostaglandin E(2) release and the upregulation of LPA(3) receptor expression. These findings identified LPA as both a growth factor and a triggering mediator of proinflammatory response in THP-1 cells.
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Affiliation(s)
- F D'Aquilio
- Department of Biology, University of Rome Tor Vergata, Via della Ricerca Scientifica, 00133 Rome, Italy
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45
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Moughal NA, Waters CM, Valentine WJ, Connell M, Richardson JC, Tigyi G, Pyne S, Pyne NJ. Protean agonism of the lysophosphatidic acid receptor-1 with Ki16425 reduces nerve growth factor-induced neurite outgrowth in pheochromocytoma 12 cells. J Neurochem 2006; 98:1920-9. [PMID: 16945108 DOI: 10.1111/j.1471-4159.2006.04009.x] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
We report here a novel role for the constitutively active lysophosphatidic acid receptor-1 (LPA(1)) receptor in providing Gbetagamma subunits for use by the Trk A receptor. This enhances the ability of nerve growth factor (NGF) to promote signalling and cell response. These conclusions were based on three lines of evidence. Firstly, the LPA(1) receptor was co-immunoprecipitated with the Trk A receptor from lysates, suggesting that these proteins form a complex. Secondly, Ki16425, a selective protean agonist of the LPA(1) receptor, decreased constitutive basal and LPA-induced LPA(1) receptor-stimulated GTPgammaS binding. Ki16425 reduced the LPA-induced activation of p42/p44 mitogen activated protein kinase (MAPK), while acting as a weak stimulator of p42/p44 MAPK on its own, properties typical of a protean agonist. Significantly, Ki16425 also reduced the NGF-induced stimulation of p42/p44 MAPK and inhibited NGF-stimulated neurite outgrowth. Thirdly, the over-expression of the C-terminal GRK-2 peptide, which sequesters Gbetagamma subunits, reduced the NGF-induced activation of p42/p44 MAPK. In contrast, the stimulation of PC12 cells with LPA leads to a predominant G(i)alpha2-mediated Trk A-independent activation of p42/p44 MAPK, where Gbetagamma subunits play a diminished role. These findings suggest a novel role for the constitutively active LPA(1) receptor in regulating NGF-induced neuronal differentiation.
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Affiliation(s)
- Noreen A Moughal
- Department of Physiology and Pharmacology, Strathclyde Institute for Biomedical Sciences, University of Strathclyde, Glasgow, UK
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46
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Waters C, Saatian B, Moughal N, Zhao Y, Tigyi G, Natarajan V, Pyne S, Pyne N. Integrin signalling regulates the nuclear localization and function of the lysophosphatidic acid receptor-1 (LPA1) in mammalian cells. Biochem J 2006; 398:55-62. [PMID: 16716145 PMCID: PMC1525019 DOI: 10.1042/bj20060155] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2006] [Revised: 05/22/2006] [Accepted: 05/23/2006] [Indexed: 12/31/2022]
Abstract
We show that LPA1 (lysophosphatidic acid receptor-1) is constitutively localized in the nucleus of mammalian cells. LPA1 also traffics from cell membranes to the nucleus in response to LPA (lysophosphatidic acid). Several lines of evidence suggest an important role for cell-matrix interaction in regulating the constitutive nuclear localization of LPA1. First, the RGDS peptide, which blocks cell matrix-induced integrin clustering and cytoskeletal rearrangement, reduced the number of cells containing LPA1 in the nucleus. Secondly, a higher proportion of cells contained nuclear LPA1 when adhesion on fibronectin-coated glass was compared with adherence to polylysine-coated glass. Thirdly, pre-treatment of cells with the Rho kinase inhibitor (Y27632) or the myosin light chain kinase inhibitor (ML9) reduced the number of cells containing nuclear LPA1. The addition of LPA and/or Ki16425 (which binds to LPA1) to isolated nuclei containing LPA1 induced the phosphorylation of several proteins with molecular masses of 34, 32, 14 and 11 kDa. These findings demonstrate that trafficking of LPA1 to the nucleus is influenced by cell-matrix interactions and that nuclear LPA1 may be involved in regulating intranuclear protein phosphorylation and signalling.
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Key Words
- cell matrix
- integrin
- lysophosphatidic acid receptor-1 (lpa1)
- nuclear protein phosphorylation
- protean agonism
- begm, bronchial epithelium growth medium
- cho, chinese hamster ovary
- cox2, cyclo-oxgenase 2
- dapi, 4′,6-diamidino-2-phenylindole
- dmem, dulbecco's modified eagle's medium
- fcs, foetal calf serum
- gpcr, g-protein-coupled receptors
- hbec, human bronchial epithelial cell
- inos, inducible nitric oxide synthase
- lpa, lysophosphatidic acid
- lpa1, lysophosphatidic acid receptor-1
- mlck, myosin light chain kinase
- ngf, nerve growth factor
- p42/p44 mapk, p42/p44 mitogen-activated protein kinase
- pla2, phospholipase a2
- ptx, pertussis toxin
- sirna, small interfering rna
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Affiliation(s)
- Catherine M. Waters
- *Department of Physiology and Pharmacology, Strathclyde Institute for Biomedical Sciences, University of Strathclyde, 27 Taylor St, Glasgow, G4 0NR, U.K
| | - Bahman Saatian
- †Department of Medicine, University of Chicago, Center for Integrative Science Building, Room 408B, 929, E.57th Street, Chicago, IL 60637, U.S.A
| | - Noreen A. Moughal
- *Department of Physiology and Pharmacology, Strathclyde Institute for Biomedical Sciences, University of Strathclyde, 27 Taylor St, Glasgow, G4 0NR, U.K
| | - Yutong Zhao
- †Department of Medicine, University of Chicago, Center for Integrative Science Building, Room 408B, 929, E.57th Street, Chicago, IL 60637, U.S.A
| | - Gabor Tigyi
- ‡Department of Physiology, University of Tennessee Health Science Center Memphis, 894 Union Avenue, Memphis, TN, U.S.A
| | - Viswanathan Natarajan
- †Department of Medicine, University of Chicago, Center for Integrative Science Building, Room 408B, 929, E.57th Street, Chicago, IL 60637, U.S.A
| | - Susan Pyne
- *Department of Physiology and Pharmacology, Strathclyde Institute for Biomedical Sciences, University of Strathclyde, 27 Taylor St, Glasgow, G4 0NR, U.K
| | - Nigel J. Pyne
- *Department of Physiology and Pharmacology, Strathclyde Institute for Biomedical Sciences, University of Strathclyde, 27 Taylor St, Glasgow, G4 0NR, U.K
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47
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Zhao Y, He D, Saatian B, Watkins T, Spannhake EW, Pyne NJ, Natarajan V. Regulation of lysophosphatidic acid-induced epidermal growth factor receptor transactivation and interleukin-8 secretion in human bronchial epithelial cells by protein kinase Cdelta, Lyn kinase, and matrix metalloproteinases. J Biol Chem 2006; 281:19501-11. [PMID: 16687414 PMCID: PMC2760938 DOI: 10.1074/jbc.m511224200] [Citation(s) in RCA: 89] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
We have demonstrated earlier that lysophosphatidic acid (LPA)-induced interleukin-8 (IL-8) secretion is regulated by protein kinase Cdelta (PKCdelta)-dependent NF-kappaB activation in human bronchial epithelial cells (HBEpCs). Here we provide evidence for signaling pathways that regulate LPA-mediated transactivation of epidermal growth factor receptor (EGFR) and the role of cross-talk between G-protein-coupled receptors and receptor-tyrosine kinases in IL-8 secretion in HBEpCs. Treatment of HBEpCs with LPA stimulated tyrosine phosphorylation of EGFR, which was attenuated by matrix metalloproteinase (MMP) inhibitor (GM6001), heparin binding (HB)-EGF inhibitor (CRM 197), and HB-EGF neutralizing antibody. Overexpression of dominant negative PKCdelta or pretreatment with a PKCdelta inhibitor (rottlerin) or Src kinase family inhibitor (PP2) partially blocked LPA-induced MMP activation, proHB-EGF shedding, and EGFR tyrosine phosphorylation. Down-regulation of Lyn kinase, but not Src kinase, by specific small interfering RNA mitigated LPA-induced MMP activation, proHB-EGF shedding, and EGFR phosphorylation. In addition, overexpression of dominant negative PKCdelta blocked LPA-induced phosphorylation and translocation of Lyn kinase to the plasma membrane. Furthermore, down-regulation of EGFR by EGFR small interfering RNA or pretreatment of cells with EGFR inhibitors AG1478 and PD158780 almost completely blocked LPA-dependent EGFR phosphorylation and partially attenuated IL-8 secretion, respectively. These results demonstrate that LPA-induced IL-8 secretion is partly dependent on EGFR transactivation regulated by PKCdelta-dependent activation of Lyn kinase and MMPs and proHB-EGF shedding, suggesting a novel mechanism of cross-talk and interaction between G-protein-coupled receptors and receptor-tyrosine kinases in HBEpCs.
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Affiliation(s)
- Yutong Zhao
- Section of Pulmonary and Critical Care Medicine, Department of Medicine, University of Chicago, Chicago, Illinois 60637, USA
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48
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Barekzi E, Roman J, Hise K, Georas S, Steinke JW. Lysophosphatidic acid stimulates inflammatory cascade in airway epithelial cells. Prostaglandins Leukot Essent Fatty Acids 2006; 74:357-63. [PMID: 16725318 DOI: 10.1016/j.plefa.2006.03.004] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/18/2005] [Accepted: 03/12/2006] [Indexed: 11/24/2022]
Abstract
Nasal polyps are benign outgrowths originating from the anterior ethmoid and maxillary sinuses. The events leading to polyp formation are unknown but evidence points to damage of the mucousal epithelium. Lysophosphatidic acid (LPA) is a water-soluble phospholipid that has been implicated in the development of allergic inflammation. We hypothesized LPA may be an important mediator in the initiation and maintenance of the inflammatory milieu of the polyp. Data was compared from unstimulated lung epithelial and when possible nasal polyp-derived epithelial cells with LPA stimulated cells. LPA receptors 1 and 2 were constitutively expressed on lung and nasal polyp-derived epithelial cells and receptor mRNA expression was decreased upon stimulation with IL-13 and IFN-gamma. When cells were treated with LPA, cellular proliferation was stimulated 2.2 fold. Supernatants from LPA stimulated cells displayed decreases in the levels of VEGF, GM-CSF, and TNF-alpha at 24h which returned to normal or increased at 48h. Our results suggest epithelial cells undergo rapid proliferation in response to LPA resulting in a transient decrease in inflammatory cytokines followed by an upregulation of these cytokines that could lead to increased inflammation.
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Affiliation(s)
- Elizabeth Barekzi
- Asthma and Allergic Disease Center, Beirne Carter Center for Immunology, Department of Medicine, University of Virginia Health System, Charlottesville, VA, USA
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49
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Ahmad M, Long JS, Pyne NJ, Pyne S. The effect of hypoxia on lipid phosphate receptor and sphingosine kinase expression and mitogen-activated protein kinase signaling in human pulmonary smooth muscle cells. Prostaglandins Other Lipid Mediat 2006; 79:278-86. [PMID: 16647641 DOI: 10.1016/j.prostaglandins.2006.03.001] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2005] [Revised: 02/04/2006] [Accepted: 03/01/2006] [Indexed: 11/24/2022]
Abstract
Both acute and chronic hypoxia had no effect on S1P(1), S1P(3) or LPA(1) receptor transcript expression in human pulmonary smooth muscle cells. However, acute hypoxia increased sphingosine kinase SK1/2 and LPP1 mRNA transcript levels, while chronic hypoxia increased SK1 mRNA transcript alone. Acute hypoxia had no effect on S1P-, PDGF- or phorbol ester (PMA)-stimulated activation of ERK-1/2, but increased the ability of S1P to activate p38 MAPK. Chronic hypoxia increased the ability of S1P to stimulate the phosphorylation of ERK-1/2. Therefore, we have demonstrated for the first time that hypoxia can lead to marked changes in the expression of genes involved in S1P production and may modify post S1P receptor signal transduction pathways.
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Affiliation(s)
- Maqsood Ahmad
- Department of Physiology and Pharmacology, Strathclyde Institute for Biomedical Sciences, University of Strathclyde, 27 Taylor St, Glasgow, G4 0NR, UK
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50
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Jourquin J, Yang N, Kam Y, Guess C, Quaranta V. Dispersal of epithelial cancer cell colonies by lysophosphatidic acid (LPA). J Cell Physiol 2006; 206:337-46. [PMID: 16110477 DOI: 10.1002/jcp.20470] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
We describe a model system in which cancer cell colonies disperse into single, highly migratory cells in response to lysophosphatidic acid (LPA). Though LPA is known to stimulate chemotaxis and chemokinesis, a colony dispersal effect has not been reported, to our knowledge. Cancer colony dispersal by LPA is comprised of an ordered sequence of events: (1) stimulation of membrane ruffling and formation of lamellipodia, (2) dissolution of adherens junctions, (3) single cell migration in a mesenchymal-like morphology we term "ginkgo-leaf." The net result is dispersal of carcinoma cells from a compact colony. We analyzed these three steps using live-cell imaging and computer-assisted quantification and measured the following parameters: onset of lamellipodia formation, lamellipodia velocity, colony dispersal, trans-epithelial resistance, migrating cell number and speed. Because hepatocyte growth factor (HGF) was described as an epithelial scatter factor, we compared it to LPA in our system and found that HGF has no epithelial colony dispersal properties and that this effect is strictly related to LPA. Given its striking similarity to tumor cell budding observed in patients, we propose that LPA-colony dispersal may provide a cellular mechanism underlying cancer invasion and as such deserves further studies.
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Affiliation(s)
- Jérôme Jourquin
- Department of Cancer Biology, Vanderbilt University Medical Center, Nashville, Tennessee 37232-6840, USA
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