1
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Modulations of urinary lipid mediators in acute bladder cystitis. Prostaglandins Other Lipid Mediat 2023; 164:106690. [PMID: 36332874 DOI: 10.1016/j.prostaglandins.2022.106690] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2022] [Revised: 10/25/2022] [Accepted: 10/31/2022] [Indexed: 11/05/2022]
Abstract
Bioactive lipids, such as lysophospholipids, ceramides, and eicosanoids and related mediators, have been demonstrated to be involved in inflammation. We aimed to investigate the possible orchestral modulations of these bioactive lipids in human inflammation. We simultaneously measured the urinary levels of lysophospholipids, ceramides, and eicosanoids and related mediators by a liquid chromatography-mass spectrometry method in patients with cystitis and control subjects. The urinary levels of lysophosphatidylcholine, lysophosphatidylethanolamine, sphingosine 1-phosphate, ceramides, prostaglandin (PG)E2 and its metabolites represented by tetranor-PGEM, several oxylipins, DHA, and lysoPAF were higher in patients with cystitis. Urinary levels of some species of glycerolysophospholipids were highly positively correlated with those of other species of the same glycerolysophospholipids. Cluster analyses revealed that lysophosphatidylcholine was close to a PGE2 metabolite, lysophosphatidylethanolamine was close to DHA, and sphingosine 1-phosphate and ceramides were close to lysoPAF. The orchestral dynamism of the lipid mediators was observed in the urine of cystitis, suggesting the necessity for simultaneous investigation of lipid mediators for translational research.
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Faria Braga E, Monteiro de Rezende Ayroza DM, de Macedo Silva MC, Santiago Nascimento T, Gomes Sanches E, Ferreira do Carmo C, Faria Pereira LP, Mazzei Albert AL, Romão Batista W, Lopes RS, Lopes CC. Synthesis of Lysoglycerophosphocholines from Crude Soybean Lecithins as Sustainable and Non-toxic Antifouling Agents against the Golden Mussel Limnoperna fortunei. ACS OMEGA 2022; 7:45197-45207. [PMID: 36530239 PMCID: PMC9753535 DOI: 10.1021/acsomega.2c05645] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/31/2022] [Accepted: 11/15/2022] [Indexed: 06/17/2023]
Abstract
This research aimed to produce, on a multigram scale, a new class of non-toxic, halogen- and metal-free antifouling agents from the abundant lecithin byproducts of industrial soybean oil extraction. Three glycerophospholipid analogues were prepared by a facile methanolysis of crude soybean lecithins and a subsequent solvent-free O-alkylation: lysoglycerophosphocholines (LGPCs) and its ether derivatives O-alkyl lysoglycerophosphocholines (ALPCs). As efficient antiproliferative agents, LGPCs and ALPCs are an eco-friendly alternative to current commercial antifoulants which possess significant toxicity to aquatic life. In situ immersion tests of coated stainless-steel nets with previously incorporated automotive paint products, LGPCs and ALPCs (1-O-octadecyl-2-O-acyl-sn-glycero-3-phosphocholine, ALPC18, and 1-O-hexadecyl-2-O-acyl-sn-glycero-3-phosphocholine, ALPC16), in an aquaculture reservoir in SP-Brazil revealed significant growth inhibition against macrofouling species, especially the epibiotic golden mussel (Limnoperna fortunei), when compared with the control. These results promise a more sustainable and ecologically innocuous approach to combating the biofouling phenomenon and the deeply concerning dissemination of the golden mussel which has provoked an economic crisis in the energy and aquaculture sectors.
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Affiliation(s)
- Esther Faria Braga
- Laboratório
de Síntese e Análise de Produtos Estratégicos, Universidade Federal do Rio de Janeiro (UFRJ), Av. Athos da Silveira Ramos, 149,
Bloco A, s.508, Cidade Universitária, Rio de Janeiro, Rio de Janeiro21941-909, Brazil
| | - Daercy Maria Monteiro de Rezende Ayroza
- Instituto
de Pesca, Agência Paulista de Tecnologia
dos Agronegócios, Av Francisco Matarazzo, 455, Parque da Água Branca, São Paulo05001-900, São Paulo, Brazil
| | - Maria Clara de Macedo Silva
- Laboratório
de Síntese e Análise de Produtos Estratégicos, Universidade Federal do Rio de Janeiro (UFRJ), Av. Athos da Silveira Ramos, 149,
Bloco A, s.508, Cidade Universitária, Rio de Janeiro, Rio de Janeiro21941-909, Brazil
| | - Thiana Santiago Nascimento
- Laboratório
de Síntese e Análise de Produtos Estratégicos, Universidade Federal do Rio de Janeiro (UFRJ), Av. Athos da Silveira Ramos, 149,
Bloco A, s.508, Cidade Universitária, Rio de Janeiro, Rio de Janeiro21941-909, Brazil
| | - Eduardo Gomes Sanches
- Instituto
de Pesca, Agência Paulista de Tecnologia
dos Agronegócios, Av Francisco Matarazzo, 455, Parque da Água Branca, São Paulo05001-900, São Paulo, Brazil
| | - Clovis Ferreira do Carmo
- Instituto
de Pesca, Agência Paulista de Tecnologia
dos Agronegócios, Av Francisco Matarazzo, 455, Parque da Água Branca, São Paulo05001-900, São Paulo, Brazil
| | - Lilian Paula Faria Pereira
- Instituto
de Pesca, Agência Paulista de Tecnologia
dos Agronegócios, Av Francisco Matarazzo, 455, Parque da Água Branca, São Paulo05001-900, São Paulo, Brazil
| | - André Luís Mazzei Albert
- Laboratório
de Síntese e Análise de Produtos Estratégicos, Universidade Federal do Rio de Janeiro (UFRJ), Av. Athos da Silveira Ramos, 149,
Bloco A, s.508, Cidade Universitária, Rio de Janeiro, Rio de Janeiro21941-909, Brazil
| | - William Romão Batista
- Laboratório
de Síntese e Análise de Produtos Estratégicos, Universidade Federal do Rio de Janeiro (UFRJ), Av. Athos da Silveira Ramos, 149,
Bloco A, s.508, Cidade Universitária, Rio de Janeiro, Rio de Janeiro21941-909, Brazil
| | - Rosangela Sabbatini
Capella Lopes
- Laboratório
de Síntese e Análise de Produtos Estratégicos, Universidade Federal do Rio de Janeiro (UFRJ), Av. Athos da Silveira Ramos, 149,
Bloco A, s.508, Cidade Universitária, Rio de Janeiro, Rio de Janeiro21941-909, Brazil
| | - Claudio Cerqueira Lopes
- Laboratório
de Síntese e Análise de Produtos Estratégicos, Universidade Federal do Rio de Janeiro (UFRJ), Av. Athos da Silveira Ramos, 149,
Bloco A, s.508, Cidade Universitária, Rio de Janeiro, Rio de Janeiro21941-909, Brazil
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Zhang K, Xu Y, Yang Y, Guo M, Zhang T, Zong B, Huang S, Suo L, Ma B, Wang X, Wu Y, Brugger D, Chen Y. Gut microbiota-derived metabolites contribute negatively to hindgut barrier function development at the early weaning goat model. ANIMAL NUTRITION 2022; 10:111-123. [PMID: 35663372 PMCID: PMC9136126 DOI: 10.1016/j.aninu.2022.04.004] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/24/2021] [Revised: 12/27/2021] [Accepted: 04/11/2022] [Indexed: 11/24/2022]
Abstract
Early weaning induces intestinal injury, leading to a series of long-term symptoms such as inflammation, malabsorption and diarrhea. In this study, we hypothesized that microbes and their metabolites modulate the host's inflammatory response to early weaning stress in a goat model. A total of 18 female Tibetan goat kids (n = 9) were weaned from their mothers at 28 d (D28) and 60 d (D60) postpartum. D60 and D28 groups were fed the same solid diet ad libitum from weaning to 75 d of age. The colonic epithelium was subject to RNA-sequencing, the caecal digesta metabolomics were assessed by liquid chromatography–tandem mass spectrometry (LC-MS/MS), and the caecal microbiota composition was analysed by 16S ribosomal RNA gene sequencing. We found that early weaning substantially increased the colonic pro-apoptotic gene expression of B-cell lymphoma associated X (Bax), caspase-9, and caspase-3, and decreased the expression of zonula occludens-1 (ZO-1) and claudin-1 (P < 0.01). In addition, a significant Bacteroides acidifaciens enrichment was observed in the hindgut of early-weaned goats (P < 0.01), which negatively correlated with lysophosphatidylcholine products. Similarly, the chemokine signaling, IL-17 signaling, and peroxisome proliferators-activated receptor (PPAR) signaling pathways were upregulated in the colonic mucosa of the early-weaned goats. By applying caecal microbiota transplantation from goats to defaunated C57/6J mice, we confirmed that caecal microbiota of D28 goat kids increased the relative abundance of B. acidifaciens and significantly up-regulated the genes of Bax, G protein–coupled receptor (GPR) 109A, GPR 43, fatty acid binding protein 6, nuclear receptor subfamily 1 group H member 3, angiotensin converting enzyme 2, and IL-6 expression (P < 0.05), and decreased ZO-1, and claudin-1 protein expression in the mice jejunum and colon (P < 0.001). These results proposed that the hindgut microbiota and metabolites mediate the barrier function weakening during early weaning, and the relative abundance of B. acidifaciens was negatively correlated with the hindgut barrier gene expression. This study demonstrates how weaning stress can affect key host–microbe interaction regulators in the hindgut, in a lysophosphatidylcholine dependent and independent manner. Furthermore, based on our mice data, these results are transferable to other mammal species.
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Knuplez E, Sturm EM, Marsche G. Emerging Role of Phospholipase-Derived Cleavage Products in Regulating Eosinophil Activity: Focus on Lysophospholipids, Polyunsaturated Fatty Acids and Eicosanoids. Int J Mol Sci 2021; 22:4356. [PMID: 33919453 PMCID: PMC8122506 DOI: 10.3390/ijms22094356] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2021] [Revised: 04/16/2021] [Accepted: 04/19/2021] [Indexed: 12/19/2022] Open
Abstract
Eosinophils are important effector cells involved in allergic inflammation. When stimulated, eosinophils release a variety of mediators initiating, propagating, and maintaining local inflammation. Both, the activity and concentration of secreted and cytosolic phospholipases (PLAs) are increased in allergic inflammation, promoting the cleavage of phospholipids and thus the production of reactive lipid mediators. Eosinophils express high levels of secreted phospholipase A2 compared to other leukocytes, indicating their direct involvement in the production of lipid mediators during allergic inflammation. On the other side, eosinophils have also been recognized as crucial mediators with regulatory and homeostatic roles in local immunity and repair. Thus, targeting the complex network of lipid mediators offer a unique opportunity to target the over-activation and 'pro-inflammatory' phenotype of eosinophils without compromising the survival and functions of tissue-resident and homeostatic eosinophils. Here we provide a comprehensive overview of the critical role of phospholipase-derived lipid mediators in modulating eosinophil activity in health and disease. We focus on lysophospholipids, polyunsaturated fatty acids, and eicosanoids with exciting new perspectives for future drug development.
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Affiliation(s)
| | | | - Gunther Marsche
- Otto Loewi Research Center, Division of Pharmacology, Medical University of Graz, 8010 Graz, Austria; (E.K.); (E.M.S.)
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Dorninger F, Forss-Petter S, Wimmer I, Berger J. Plasmalogens, platelet-activating factor and beyond - Ether lipids in signaling and neurodegeneration. Neurobiol Dis 2020; 145:105061. [PMID: 32861763 PMCID: PMC7116601 DOI: 10.1016/j.nbd.2020.105061] [Citation(s) in RCA: 41] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2020] [Revised: 08/20/2020] [Accepted: 08/22/2020] [Indexed: 12/12/2022] Open
Abstract
Glycerol-based ether lipids including ether phospholipids form a specialized branch of lipids that in mammals require peroxisomes for their biosynthesis. They are major components of biological membranes and one particular subgroup, the plasmalogens, is widely regarded as a cellular antioxidant. Their vast potential to influence signal transduction pathways is less well known. Here, we summarize the literature showing associations with essential signaling cascades for a wide variety of ether lipids, including platelet-activating factor, alkylglycerols, ether-linked lysophosphatidic acid and plasmalogen-derived polyunsaturated fatty acids. The available experimental evidence demonstrates links to several common players like protein kinase C, peroxisome proliferator-activated receptors or mitogen-activated protein kinases. Furthermore, ether lipid levels have repeatedly been connected to some of the most abundant neurological diseases, particularly Alzheimer’s disease and more recently also neurodevelopmental disorders like autism. Thus, we critically discuss the potential role of these compounds in the etiology and pathophysiology of these diseases with an emphasis on signaling processes. Finally, we review the emerging interest in plasmalogens as treatment target in neurological diseases, assessing available data and highlighting future perspectives. Although many aspects of ether lipid involvement in cellular signaling identified in vitro still have to be confirmed in vivo, the compiled data show many intriguing properties and contributions of these lipids to health and disease that will trigger further research.
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Affiliation(s)
- Fabian Dorninger
- Department of Pathobiology of the Nervous System, Center for Brain Research, Medical University of Vienna, Spitalgasse 4, Vienna 1090, Austria.
| | - Sonja Forss-Petter
- Department of Pathobiology of the Nervous System, Center for Brain Research, Medical University of Vienna, Spitalgasse 4, Vienna 1090, Austria
| | - Isabella Wimmer
- Department of Neurology, Medical University of Vienna, Währinger Gürtel 18-20, Vienna 1090, Austria
| | - Johannes Berger
- Department of Pathobiology of the Nervous System, Center for Brain Research, Medical University of Vienna, Spitalgasse 4, Vienna 1090, Austria.
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6
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Effect of acyl and alkyl analogs of platelet-activating factor on inflammatory signaling. Prostaglandins Other Lipid Mediat 2020; 151:106478. [PMID: 32711129 DOI: 10.1016/j.prostaglandins.2020.106478] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2020] [Revised: 07/20/2020] [Accepted: 07/20/2020] [Indexed: 01/11/2023]
Abstract
Platelet-activating factor (PAF), a bioactive ether phospholipid with significant pro-inflammatory properties, was identified almost half a century ago. Despite extensive study of this autocoid, therapeutic strategies for targeting its signaling components have not been successful, including the recent clinical trials with darapladib, a drug that targets plasma PAF-acetylhydrolase (PAF-AH). We recently provided experimental evidence that the previously unrecognized acyl analog of PAF, which is concomitantly produced along with PAF during biosynthesis, dampens PAF signaling by acting both as a sacrificial substrate for PAF-AH and probably as an endogenous PAF-receptor antagonist/partial agonist. If this is the scenario in vivo, PAF-AH needs to catalyze the selective hydrolysis of alkyl-PAF and not acyl-PAF. Accordingly, different approaches are needed for treating inflammatory diseases in which PAF signaling is implicated. The interplay between acyl-PAF, alkyl-PAF, PAF-AH, and PAF-R is complex, and the outcome of this interplay has not been previously appreciated. In this review, we discuss this interaction based on our recent findings. It is very likely that the relative abundance of acyl and alkyl-PAF and their interactions with PAF-R in the presence of their hydrolyzing enzyme PAF-AH may exert a modulatory effect on PAF signaling during inflammation.
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Knuplez E, Marsche G. An Updated Review of Pro- and Anti-Inflammatory Properties of Plasma Lysophosphatidylcholines in the Vascular System. Int J Mol Sci 2020; 21:ijms21124501. [PMID: 32599910 PMCID: PMC7350010 DOI: 10.3390/ijms21124501] [Citation(s) in RCA: 85] [Impact Index Per Article: 21.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2020] [Revised: 06/19/2020] [Accepted: 06/23/2020] [Indexed: 12/14/2022] Open
Abstract
Lysophosphatidylcholines are a group of bioactive lipids heavily investigated in the context of inflammation and atherosclerosis development. While present in plasma during physiological conditions, their concentration can drastically increase in certain inflammatory states. Lysophosphatidylcholines are widely regarded as potent pro-inflammatory and deleterious mediators, but an increasing number of more recent studies show multiple beneficial properties under various pathological conditions. Many of the discrepancies in the published studies are due to the investigation of different species or mixtures of lysophatidylcholines and the use of supra-physiological concentrations in the absence of serum or other carrier proteins. Furthermore, interpretation of the results is complicated by the rapid metabolism of lysophosphatidylcholine (LPC) in cells and tissues to pro-inflammatory lysophosphatidic acid. Interestingly, most of the recent studies, in contrast to older studies, found lower LPC plasma levels associated with unfavorable disease outcomes. Being the most abundant lysophospholipid in plasma, it is of utmost importance to understand its physiological functions and shed light on the discordant literature connected to its research. LPCs should be recognized as important homeostatic mediators involved in all stages of vascular inflammation. In this review, we want to point out potential pro- and anti-inflammatory activities of lysophospholipids in the vascular system and highlight recent discoveries about the effect of lysophosphatidylcholines on immune cells at the endothelial vascular interface. We will also look at their potential clinical application as biomarkers.
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Affiliation(s)
- Eva Knuplez
- Division of Pharmacology, Otto Loewi Research Center, Medical University of Graz, 8010 Graz, Austria
- Correspondence: (E.K.); (G.M.); Tel.: +43-385-74115 (E.K.); +43-316-385-74128 (G.M.)
| | - Gunther Marsche
- Division of Pharmacology, Otto Loewi Research Center, Medical University of Graz, 8010 Graz, Austria
- BioTechMed-Graz, 8010 Graz, Austria
- Correspondence: (E.K.); (G.M.); Tel.: +43-385-74115 (E.K.); +43-316-385-74128 (G.M.)
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Law SH, Chan ML, Marathe GK, Parveen F, Chen CH, Ke LY. An Updated Review of Lysophosphatidylcholine Metabolism in Human Diseases. Int J Mol Sci 2019; 20:ijms20051149. [PMID: 30845751 PMCID: PMC6429061 DOI: 10.3390/ijms20051149] [Citation(s) in RCA: 385] [Impact Index Per Article: 77.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2019] [Revised: 02/27/2019] [Accepted: 02/28/2019] [Indexed: 12/12/2022] Open
Abstract
Lysophosphatidylcholine (LPC) is increasingly recognized as a key marker/factor positively associated with cardiovascular and neurodegenerative diseases. However, findings from recent clinical lipidomic studies of LPC have been controversial. A key issue is the complexity of the enzymatic cascade involved in LPC metabolism. Here, we address the coordination of these enzymes and the derangement that may disrupt LPC homeostasis, leading to metabolic disorders. LPC is mainly derived from the turnover of phosphatidylcholine (PC) in the circulation by phospholipase A2 (PLA2). In the presence of Acyl-CoA, lysophosphatidylcholine acyltransferase (LPCAT) converts LPC to PC, which rapidly gets recycled by the Lands cycle. However, overexpression or enhanced activity of PLA2 increases the LPC content in modified low-density lipoprotein (LDL) and oxidized LDL, which play significant roles in the development of atherosclerotic plaques and endothelial dysfunction. The intracellular enzyme LPCAT cannot directly remove LPC from circulation. Hydrolysis of LPC by autotaxin, an enzyme with lysophospholipase D activity, generates lysophosphatidic acid, which is highly associated with cancers. Although enzymes with lysophospholipase A1 activity could theoretically degrade LPC into harmless metabolites, they have not been found in the circulation. In conclusion, understanding enzyme kinetics and LPC metabolism may help identify novel therapeutic targets in LPC-associated diseases.
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Affiliation(s)
- Shi-Hui Law
- Department of Medical Laboratory Science and Biotechnology, College of Health Sciences, Kaohsiung Medical University, Kaohsiung 80708, Taiwan.
| | - Mei-Lin Chan
- Center for Lipid Biosciences, Kaohsiung Medical University Hospital, Kaohsiung 80708, Taiwan.
- Division of Thoracic Surgery, Department of Surgery, MacKay Memorial Hospital, MacKay Medical College, Taipei 10449, Taiwan.
| | - Gopal K Marathe
- Department of Studies in Biochemistry, Manasagangothri, University of Mysore, Mysore-570006, India.
| | - Farzana Parveen
- Department of Medical Laboratory Science and Biotechnology, College of Health Sciences, Kaohsiung Medical University, Kaohsiung 80708, Taiwan.
| | - Chu-Huang Chen
- Center for Lipid Biosciences, Kaohsiung Medical University Hospital, Kaohsiung 80708, Taiwan.
- Lipid Science and Aging Research Center, Kaohsiung Medical University, Kaohsiung 80708, Taiwan.
- Graduate Institute of Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung 80708, Taiwan.
- Vascular and Medicinal Research, Texas Heart Institute, Houston, TX 77030, USA.
| | - Liang-Yin Ke
- Department of Medical Laboratory Science and Biotechnology, College of Health Sciences, Kaohsiung Medical University, Kaohsiung 80708, Taiwan.
- Center for Lipid Biosciences, Kaohsiung Medical University Hospital, Kaohsiung 80708, Taiwan.
- Lipid Science and Aging Research Center, Kaohsiung Medical University, Kaohsiung 80708, Taiwan.
- Graduate Institute of Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung 80708, Taiwan.
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Chaithra VH, Jacob SP, Lakshmikanth CL, Sumanth MS, Abhilasha KV, Chen CH, Thyagarajan A, Sahu RP, Travers JB, McIntyre TM, Kemparaju K, Marathe GK. Modulation of inflammatory platelet-activating factor (PAF) receptor by the acyl analogue of PAF. J Lipid Res 2018; 59:2063-2074. [PMID: 30139761 DOI: 10.1194/jlr.m085704] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2018] [Revised: 08/20/2018] [Indexed: 11/20/2022] Open
Abstract
Platelet-activating factor (PAF) is a potent inflammatory mediator that exerts its actions via the single PAF receptor (PAF-R). Cells that biosynthesize alkyl-PAF also make abundant amounts of the less potent PAF analogue acyl-PAF, which competes for PAF-R. Both PAF species are degraded by the plasma form of PAF acetylhydrolase (PAF-AH). We examined whether cogenerated acyl-PAF protects alkyl-PAF from systemic degradation by acting as a sacrificial substrate to enhance inflammatory stimulation or as an inhibitor to dampen PAF-R signaling. In ex vivo experiments both PAF species are prothrombotic in isolation, but acyl-PAF reduced the alkyl-PAF-induced stimulation of human platelets that express canonical PAF-R. In Swiss albino mice, alkyl-PAF causes sudden death, but this effect can also be suppressed by simultaneously administering boluses of acyl-PAF. When PAF-AH levels were incrementally elevated, the protective effect of acyl-PAF on alkyl-PAF-induced death was serially decreased. We conclude that, although acyl-PAF in isolation is mildly proinflammatory, in a pathophysiological setting abundant acyl-PAF suppresses the action of alkyl-PAF. These studies provide evidence for a previously unrecognized role for acyl-PAF as an inflammatory set-point modulator that regulates both PAF-R signaling and hydrolysis.
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Affiliation(s)
| | - Shancy Petsel Jacob
- Department of Studies in Biochemistry University of Mysore, Manasagangothri, Mysuru 570006, India
| | | | - Mosale Seetharam Sumanth
- Department of Studies in Biochemistry University of Mysore, Manasagangothri, Mysuru 570006, India
| | | | - Chu-Huang Chen
- Vascular and Medicinal Research, Texas Heart Institute, Houston, TX 77030
| | - Anita Thyagarajan
- Department of Pharmacology and Toxicology, Boonshoft School of Medicine, Wright State University, Dayton, OH 45435
| | - Ravi P Sahu
- Department of Pharmacology and Toxicology, Boonshoft School of Medicine, Wright State University, Dayton, OH 45435
| | - Jeffery Bryant Travers
- Department of Pharmacology and Toxicology, Boonshoft School of Medicine, Wright State University, Dayton, OH 45435
| | - Thomas M McIntyre
- Department of Cellular and Molecular Medicine, Cleveland Clinic Lerner Research Institute, Cleveland, OH
| | - Kempaiah Kemparaju
- Department of Studies in Biochemistry University of Mysore, Manasagangothri, Mysuru 570006, India
| | - Gopal Kedihithlu Marathe
- Department of Studies in Biochemistry University of Mysore, Manasagangothri, Mysuru 570006, India .,and Department of Studies in Molecular Biology, University of Mysore, Manasagangothri, Mysuru 570006, India
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10
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McVey MJ, Kim M, Tabuchi A, Srbely V, Japtok L, Arenz C, Rotstein O, Kleuser B, Semple JW, Kuebler WM. Acid sphingomyelinase mediates murine acute lung injury following transfusion of aged platelets. Am J Physiol Lung Cell Mol Physiol 2017; 312:L625-L637. [DOI: 10.1152/ajplung.00317.2016] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2016] [Revised: 03/06/2017] [Accepted: 03/06/2017] [Indexed: 11/22/2022] Open
Abstract
Pulmonary complications from stored blood products are the leading cause of mortality related to transfusion. Transfusion-related acute lung injury is mediated by antibodies or bioactive mediators, yet underlying mechanisms are incompletely understood. Sphingolipids such as ceramide regulate lung injury, and their composition changes as a function of time in stored blood. Here, we tested the hypothesis that aged platelets may induce lung injury via a sphingolipid-mediated mechanism. To assess this hypothesis, a two-hit mouse model was devised. Recipient mice were treated with 2 mg/kg intraperitoneal lipopolysaccharide (priming) 2 h before transfusion of 10 ml/kg stored (1–5 days) platelets treated with or without addition of acid sphingomyelinase inhibitor ARC39 or platelets from acid sphingomyelinase-deficient mice, which both reduce ceramide formation. Transfused mice were examined for signs of pulmonary neutrophil accumulation, endothelial barrier dysfunction, and histological evidence of lung injury. Sphingolipid profiles in stored platelets were analyzed by mass spectrophotometry. Transfusion of aged platelets into primed mice induced characteristic features of lung injury, which increased in severity as a function of storage time. Ceramide accumulated in platelets during storage, but this was attenuated by ARC39 or in acid sphingomyelinase-deficient platelets. Compared with wild-type platelets, transfusion of ARC39-treated or acid sphingomyelinase-deficient aged platelets alleviated lung injury. Aged platelets elicit lung injury in primed recipient mice, which can be alleviated by pharmacological inhibition or genetic deletion of acid sphingomyelinase. Interventions targeting sphingolipid formation represent a promising strategy to increase the safety and longevity of stored blood products.
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Affiliation(s)
- Mark J. McVey
- Keenan Research Centre for Biomedical Science, St. Michael’s Hospital, Toronto, Ontario, Canada
- Departments of Anesthesia and Physiology, University of Toronto, and Department of Anesthesia and Pain Medicine Sickkids Hospital, Toronto, Ontario, Canada
| | - Michael Kim
- Keenan Research Centre for Biomedical Science, St. Michael’s Hospital, Toronto, Ontario, Canada
| | - Arata Tabuchi
- Keenan Research Centre for Biomedical Science, St. Michael’s Hospital, Toronto, Ontario, Canada
| | - Victoria Srbely
- Keenan Research Centre for Biomedical Science, St. Michael’s Hospital, Toronto, Ontario, Canada
| | - Lukasz Japtok
- Institute of Nutritional Science, University of Potsdam, Potsdam, Germany
| | - Christoph Arenz
- Institute for Chemistry, Humboldt University, Berlin, Germany
| | - Ori Rotstein
- Keenan Research Centre for Biomedical Science, St. Michael’s Hospital, Toronto, Ontario, Canada
- Department of Surgery University of Toronto, Toronto, Ontario, Canada
| | - Burkhard Kleuser
- Institute of Nutritional Science, University of Potsdam, Potsdam, Germany
| | - John W. Semple
- Keenan Research Centre for Biomedical Science, St. Michael’s Hospital, Toronto, Ontario, Canada
- Departments of Pharmacology, Medicine, and Laboratory Medicine and Pathobiology, University of Toronto, Toronto, Ontario, Canada
| | - Wolfgang M. Kuebler
- Keenan Research Centre for Biomedical Science, St. Michael’s Hospital, Toronto, Ontario, Canada
- Department of Surgery University of Toronto, Toronto, Ontario, Canada
- Department of Physiology University of Toronto, Toronto, Ontario, Canada
- Institute of Physiology, Charité-Univcersitätsmedizin Berlin, Germany; and
- German Heart Institute, Berlin, Germany
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11
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Fu J, Cuppen BVJ, Welsing PMJ, van Wietmarschen H, Harms AC, Berger R, Koval S, Fritsch-Stork RDE, Bijlsma JWJ, Hankemeier T, van der Greef J, Lafeber FPJG. Differences between serum polar lipid profiles of male and female rheumatoid arthritis patients in response to glucocorticoid treatment. Inflammopharmacology 2016; 24:397-402. [PMID: 27682325 PMCID: PMC5119840 DOI: 10.1007/s10787-016-0284-1] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2016] [Accepted: 09/21/2016] [Indexed: 01/18/2023]
Abstract
Objective As there are pharmacological differences between males and females, and glucocorticoid (GC) treatment is associated with increased cardiovascular mortality rate in rheumatoid arthritis (RA) patients, it is important to study serum polar lipid profiles of male and female patients in response to GC therapy. Gender differences may require an adjustment to the treatment strategy for a selection of patients. Methods Serum samples from 281 RA patients were analysed using a targeted lipidomics platform. The differences in GC use and gender on polar lipid profiles were cross sectionally examined by multiple linear regressions, while correcting for confounding factors. Results Differences in polar lipids between GC users and non-GC users in females and males were merely restricted to lysophospholipids (lysophosphatidylcholines and lysophosphatidylethanolamines). Lysophospholipids in female patients treated with GCs were significantly higher than female patients not treated with GCs (p = 6.0 E−6), whereas no significant difference was observed in male GC users versus non-users (p = 0.397). Conclusion The lysophospholipid profiles in response to GCs were significantly different between male and female RA patients, which may have implications for the cardiovascular risk of GC treatment. Electronic supplementary material The online version of this article (doi:10.1007/s10787-016-0284-1) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Junzeng Fu
- Leiden Academic Center for Drug Research, Leiden University, Einsteinweg 55, 2333 CC, Leiden, The Netherlands. .,Sino-Dutch Center for Preventive and Personalized Medicine, P.O. Box 360, 3700 AJ, Zeist, The Netherlands.
| | - Bart V J Cuppen
- Rheumatology and Clinical Immunology, University Medical Center Utrecht, F02.127, Heidelberglaan 100, 3584 CX, Utrecht, The Netherlands
| | - Paco M J Welsing
- Rheumatology and Clinical Immunology, University Medical Center Utrecht, F02.127, Heidelberglaan 100, 3584 CX, Utrecht, The Netherlands
| | - Herman van Wietmarschen
- Sino-Dutch Center for Preventive and Personalized Medicine, P.O. Box 360, 3700 AJ, Zeist, The Netherlands
| | - Amy C Harms
- Leiden Academic Center for Drug Research, Leiden University, Einsteinweg 55, 2333 CC, Leiden, The Netherlands.,Netherlands Metabolomics Center, Einsteinweg 55, 2333 CC, Leiden, The Netherlands
| | - Ruud Berger
- Leiden Academic Center for Drug Research, Leiden University, Einsteinweg 55, 2333 CC, Leiden, The Netherlands.,Netherlands Metabolomics Center, Einsteinweg 55, 2333 CC, Leiden, The Netherlands
| | - Slavik Koval
- Leiden Academic Center for Drug Research, Leiden University, Einsteinweg 55, 2333 CC, Leiden, The Netherlands.,Netherlands Metabolomics Center, Einsteinweg 55, 2333 CC, Leiden, The Netherlands
| | - Ruth D E Fritsch-Stork
- Rheumatology and Clinical Immunology, University Medical Center Utrecht, F02.127, Heidelberglaan 100, 3584 CX, Utrecht, The Netherlands.,1st Medical Department and Ludwig Boltzmann Institute of Osteology at the Hanusch Hospital of WGKK and AUVA Trauma Centre Meidling, Hanusch Hospital, Heinrich-Collin-Straße 30, 1140, Vienna, Austria.,Sigmund Freud University, Freudplatz 1, 1020, Vienna, Austria
| | - Johannes W J Bijlsma
- Rheumatology and Clinical Immunology, University Medical Center Utrecht, F02.127, Heidelberglaan 100, 3584 CX, Utrecht, The Netherlands
| | - Thomas Hankemeier
- Leiden Academic Center for Drug Research, Leiden University, Einsteinweg 55, 2333 CC, Leiden, The Netherlands.,Netherlands Metabolomics Center, Einsteinweg 55, 2333 CC, Leiden, The Netherlands
| | - Jan van der Greef
- Leiden Academic Center for Drug Research, Leiden University, Einsteinweg 55, 2333 CC, Leiden, The Netherlands.,Sino-Dutch Center for Preventive and Personalized Medicine, P.O. Box 360, 3700 AJ, Zeist, The Netherlands.,TNO, Netherlands Organization for Applied Scientific Research, Microbiology and Systems Biology, Zeist, The Netherlands.,Netherlands Metabolomics Center, Einsteinweg 55, 2333 CC, Leiden, The Netherlands
| | - Floris P J G Lafeber
- Rheumatology and Clinical Immunology, University Medical Center Utrecht, F02.127, Heidelberglaan 100, 3584 CX, Utrecht, The Netherlands
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12
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Eleftheriou K, Sideratou Z, Thanassoulas A, Papakyriakou A, Tsiourvas D. Comparative Experimental and Computational Study of Monoalkyl Chain Phosphatidylcholine-Containing Thermoresponsive Liposomes. J Phys Chem B 2016; 120:5417-28. [PMID: 27280363 DOI: 10.1021/acs.jpcb.6b02783] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Liposomes containing lysophospholipids are intensively studied as drug delivery systems that are stable at normal body temperature but exhibit fast release of their drug load at slightly elevated temperatures. In this study, the stability and release properties of dipalmitoylglycerophosphocholine (DPPC)-based liposomes incorporating the commonly used lysophosphatidylocholine (lyso-PC), and a series of monoalkyl chain ether-linked phosphatidylcholine, i.e., the biologically relevant monoalkyl chain platelet activating factor (PAF) and its derivatives lyso-PAF and methyl-PAF, were investigated. To this end a series of PEGylated small unilamellar liposomes with DPPC:monoalkyl lipid compositions of 5% and 10% molar ratio were prepared and compared with regard to stability (37 °C) and release properties at elevated temperatures (38-43 °C). All systems were characterized with respect to size distribution, ζ-potential, and phase transition characteristics. The presence of ether-lipids endows liposomes with superior (∼10% increase) release properties at 5% incorporation compared to lyso-PC, while at 10% molar ratio the formulations do not differ significantly, the release being close to 90%. The findings are supported by atomistic molecular dynamics simulations that suggest a correlation between the enhanced permeability and increased penetration of water molecules within the bilayers with density fluctuations resulting from the increased area-per-lipid and the disorder of the lysolipids alkyl chains.
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Affiliation(s)
- Kleopatra Eleftheriou
- Institute of Nanoscience and Nanotechology, NCSR ''Demokritos" , 15310 Aghia Paraskevi, Attiki, Greece
| | - Zili Sideratou
- Institute of Nanoscience and Nanotechology, NCSR ''Demokritos" , 15310 Aghia Paraskevi, Attiki, Greece
| | - Angelos Thanassoulas
- Institute of Nuclear & Radiological Sciences and Technology, Energy & Safety, NCSR ''Demokritos" , 15310 Aghia Paraskevi, Attiki, Greece
| | - Athanasios Papakyriakou
- Institute of Nanoscience and Nanotechology, NCSR ''Demokritos" , 15310 Aghia Paraskevi, Attiki, Greece
| | - Dimitris Tsiourvas
- Institute of Nanoscience and Nanotechology, NCSR ''Demokritos" , 15310 Aghia Paraskevi, Attiki, Greece
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Ikhlef S, Berrougui H, Kamtchueng Simo O, Khalil A. Paraoxonase 1-treated oxLDL promotes cholesterol efflux from macrophages by stimulating the PPARγ-LXRα-ABCA1 pathway. FEBS Lett 2016; 590:1614-29. [DOI: 10.1002/1873-3468.12198] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2015] [Revised: 03/17/2016] [Accepted: 04/04/2016] [Indexed: 02/03/2023]
Affiliation(s)
- Souade Ikhlef
- Research Centre on Aging; CSSS-IUGS; Sherbrooke Canada
| | - Hicham Berrougui
- Research Centre on Aging; CSSS-IUGS; Sherbrooke Canada
- Department of Biology; University Sultan My Slimane; Beni Mellal Morocco
| | | | - Abdelouahed Khalil
- Research Centre on Aging; CSSS-IUGS; Sherbrooke Canada
- Department of Medicine; Geriatrics Service; Faculty of Medicine and Biological Sciences; University of Sherbrooke; Canada
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14
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Sato A, Yokoyama I, Ebina K. Biotinylated heptapeptides substituted with a D-amino acid as platelet-activating factor inhibitors. Eur J Pharmacol 2015; 764:202-207. [PMID: 26142829 DOI: 10.1016/j.ejphar.2015.06.062] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2015] [Revised: 06/22/2015] [Accepted: 06/30/2015] [Indexed: 10/23/2022]
Abstract
Platelet-activating factor (PAF), a potent lipid mediator, is implicated in many inflammatory diseases, and therefore may serve as a direct target for anti-inflammatory drugs. We previously reported that synthetic biotinylated peptides having a Tyr-Lys-Asp-Gly sequence markedly inhibit PAF-induced inflammation by direct binding, and that two synthetic fluorescence-labelled heptapeptides (Lys-Trp-Tyr-Lys-Asp-Gly-Asp and D-Lys-Trp-Tyr-Lys-Asp-Gly-Asp) with high stability in plasma specifically bind to PAF-like lipids (oxidized- and lyso-phosphatidylchoine). In this study, synthetic heptapeptides (Lys-Trp-Tyr-Lys-Asp-Gly-Asp) coupled to a biotin molecule through the N-terminal amino group and ε-amino group of N-terminus Lys, (Btn)KP6 and K(Btn)P6, respectively, and their biotinylated peptides substituted with D-Lys at the N-terminus, (Btn)dKP6 and dK(Btn)P6, respectively, were investigated for their effects on PAF-induced inflammation. In the experiments using a rat model of hind paw oedema, (Btn)KP6, K(Btn)P6, (Btn)dKP6, and dK(Btn)P6 significantly inhibited PAF-induced paw oedema, with the highest inhibitory effect exhibited by dK(Btn)P6. The inhibitory effect of D-Tyr-D-Lys-D-Asp-Gly tetrapeptide on PAF-induced paw oedema was much lower than that of Tyr-Lys-Asp-Gly tetrapeptide. In the experiments using tryptophan fluorescence spectroscopy, (Btn)KP6, K(Btn)P6, (Btn)dKP6, and dK(Btn)P6 bound to PAF dose-dependently, with dK(Btn)P6 showing the strongest binding affinity, indicating that its affinity appears to be closely correlated with its inhibitory effect on PAF-induced inflammation. These results suggest that direct binding of (Btn)KP6, K(Btn)P6, (Btn)dKP6, and dK(Btn)P6 to PAF can lead to marked inhibition of PAF-induced inflammation, and these agents, particularly dK(Btn)P6, may be useful as anti-inflammatory drugs targeting PAF with high stability in plasma.
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Affiliation(s)
- Akira Sato
- Faculty of Pharmacy, Iwaki Meisei University, 5-5-1, Chuodai-Iino, Iwaki, Fukushima 970-8551, Japan.
| | - Izumi Yokoyama
- Faculty of Pharmacy, Iwaki Meisei University, 5-5-1, Chuodai-Iino, Iwaki, Fukushima 970-8551, Japan
| | - Keiichi Ebina
- Faculty of Pharmacy, Iwaki Meisei University, 5-5-1, Chuodai-Iino, Iwaki, Fukushima 970-8551, Japan
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15
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C-reactive protein specifically enhances platelet-activating factor-induced inflammatory activity in vivo. Eur J Pharmacol 2014; 745:46-51. [DOI: 10.1016/j.ejphar.2014.10.020] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2014] [Revised: 09/16/2014] [Accepted: 10/06/2014] [Indexed: 11/19/2022]
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Affiliation(s)
- Diana M Stafforini
- Department of Internal Medicine University of Utah, Salt Lake City, UT 84112 Huntsman Cancer Institute, University of Utah, Salt Lake City, UT 84112
| | - Guy A Zimmerman
- Department of Internal Medicine University of Utah, Salt Lake City, UT 84112
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Sato A, Kumagai T, Ebina K. A synthetic biotinylated peptide, BP21, inhibits the induction of mRNA expression of inflammatory substances by oxidized- and lyso-phosphatidylcholine. Drug Dev Res 2014; 75:246-56. [PMID: 24890951 DOI: 10.1002/ddr.21178] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2014] [Accepted: 05/07/2014] [Indexed: 11/10/2022]
Abstract
Preclinical Research Oxidized low-density lipoprotein (ox-LDL) is implicated in many inflammatory diseases, e.g., type 2 diabetes, obesity, atherosclerosis, and metabolic syndrome. We previously reported that a synthetic biotinylated peptide, BP21, inhibits the bioactivity of ox-LDL via direct binding to ox-LDL. Here, we investigated the effect of BP21 on the mRNA expression of proinflammatory mediators induced by two major components of ox-LDL, oxidized- and lyso-phosphatidylcholine (ox-PC and LPC), in monocytes/macrophages (THP-1 cells) and adipocytes (3T3-L1 cells). In THP-1 cells, BP21 markedly reduced the mRNA expression of interleukin (IL)-6, adipocyte fatty acid-binding protein (aP2), tumor necrosis factor-α, and mitogen-activated protein kinase phosphatase-1, which are induced by one of the major bioactive components of ox-PC, 1-palmitoyl-2-(5'-oxo-valeroyl)-sn-glycero-3-phosphocholine (POVPC), and reduced the mRNA expression of IL-6, the ox-LDL-specific scavenger receptor CD36, and aP2 induced by LPC. In adipocytes, the mRNA expression of IL-1β as an adipokine and aP2 is highly induced by ox-PC and LPC, and BP21 markedly reduced the mRNA expression of IL-1β and aP2 induced by POVPC and LPC. Furthermore, BP21 specifically bound to LPC and POVPC in a dose-dependent manner. These results suggest that BP21 may be useful lead for the potential treatment and prevention of inflammatory diseases caused by ox-PC and LPC.
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Affiliation(s)
- Akira Sato
- Faculty of Pharmacy, Iwaki Meisei University, Iwaki, Fukushima, 970-8551, Japan
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18
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Marathe GK, Pandit C, Lakshmikanth CL, Chaithra VH, Jacob SP, D'Souza CJM. To hydrolyze or not to hydrolyze: the dilemma of platelet-activating factor acetylhydrolase. J Lipid Res 2014; 55:1847-54. [PMID: 24859738 DOI: 10.1194/jlr.r045492] [Citation(s) in RCA: 62] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Mounting ambiguity persists around the functional role of the plasma form of platelet-activating factor acetylhydrolase (PAF-AH). Because PAF-AH hydrolyzes PAF and related oxidized phospholipids, it is widely accepted as an anti-inflammatory enzyme. On the other hand, its actions can also generate lysophosphatidylcholine (lysoPC), a component of bioactive atherogenic oxidized LDL, thus allowing the enzyme to have proinflammatory capabilities. Presence of a canonical lysoPC receptor has been seriously questioned for a multitude of reasons. Animal models of inflammation show that elevating PAF-AH levels is beneficial and not deleterious and overexpression of PAF receptor (PAF-R) also augments inflammatory responses. Further, many Asian populations have a catalytically inert PAF-AH that appears to be a severity factor in a range of inflammatory disorders. Correlation found with elevated levels of PAF-AH and CVDs has led to the design of a specific PAF-AH inhibitor, darapladib. However, in a recently concluded phase III STABILITY clinical trial, use of darapladib did not yield promising results. Presence of structurally related multiple ligands for PAF-R with varied potency, existence of multi-molecular forms of PAF-AH, broad substrate specificity of the enzyme and continuous PAF production by the so called bi-cycle of PAF makes PAF more enigmatic. This review seeks to address the above concerns.
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Affiliation(s)
- Gopal Kedihitlu Marathe
- Department of Studies in Biochemistry, University of Mysore, Manasagangothri, Mysore 570006, India
| | - Chaitanya Pandit
- Department of Studies in Biochemistry, University of Mysore, Manasagangothri, Mysore 570006, India
| | | | | | - Shancy Petsel Jacob
- Department of Studies in Biochemistry, University of Mysore, Manasagangothri, Mysore 570006, India
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Common mechanism in endothelin-3 and PAF receptor function for anti-inflammatory responses. Eur J Pharmacol 2013; 718:30-3. [DOI: 10.1016/j.ejphar.2013.09.025] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2013] [Revised: 08/20/2013] [Accepted: 09/08/2013] [Indexed: 11/17/2022]
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20
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Nasopoulou C, Gogaki V, Panagopoulou E, Demopoulos C, Zabetakis I. Hen egg yolk lipid fractions with antiatherogenic properties. Anim Sci J 2012; 84:264-71. [PMID: 23480708 DOI: 10.1111/j.1740-0929.2012.01067.x] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2012] [Accepted: 06/26/2012] [Indexed: 11/29/2022]
Abstract
Three different types of hen egg yolk, cage-free, organic and daily fresh, were tested for their antiatherogenic properties. Total lipids (TL) of all hen egg yolk samples were extracted by the method of Bligh and Dyer and further separated into total polar lipids (TPL) and total neutral lipids (TNL) by counter current distribution chromatography. TPL and TNL were further separated by preparative thin-layer chromatography (TLC). TL, TPL, TNL and the obtained polar and neutral lipid fractions after TLC separation were tested to determine whether they induce platelet activation or inhibit platelet activating factor (PAF)-induced platelet activation. All three hen egg yolk TL samples possessed strong inhibitory activity against PAF-induced platelet activation that was mainly attributed to TPL, especially to PL fraction 4. Cage-free hen egg yolk exhibited the most potent anti-PAF activity in all lipid classes (TL, TPL and TNL). Thus hen egg yolk contains PAF inhibitors that reinforce their nutritional value in terms of protection against cardiovascular diseases, since PAF is a crucial inflammatory phospholipid mediator that is implicated in the mechanism of atherogenesis.
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Affiliation(s)
- Constantina Nasopoulou
- Laboratory of Food Chemistry, Department of Chemistry, National and Kapodistrian University of Athens, Athens, Greece
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21
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Sato A, Kumagai T, Aoki J, Ebina K. Synthetic biotinylated peptide compounds derived from Asp-hemolysin: novel potent inhibitors of platelet-activating factor. Eur J Pharmacol 2012; 685:205-12. [PMID: 22542654 DOI: 10.1016/j.ejphar.2012.04.025] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2011] [Revised: 03/22/2012] [Accepted: 04/05/2012] [Indexed: 11/29/2022]
Abstract
Platelet-activating factor (PAF: 1-O-alkyl-2-acetyl-sn-glycero-3-phosphocholine), a potent inflammatory mediator, is implicated in many inflammatory diseases and may possibly serve as a direct target for anti-inflammatory drugs. We have previously reported that Asp-hemolysin-related synthetic peptides (P4-P29) inhibit the bioactivities of oxidized low-density lipoprotein (ox-LDL) containing PAF-like lipids by direct binding to ox-LDL, which plays a key role in the atherosclerotic inflammatory process. In this study, we investigated whether these peptides inhibit the bioactivities of PAF by binding to PAF and its metabolite/precursor lyso-PAF. In in vitro experiments, P21, one of the peptides, bound to both PAF and lyso-PAF in a dose-dependent manner and markedly inhibited PAF-induced apoptosis in human umbilical vein endothelial cells. Moreover, in in vivo experiments, P4 and P21, particularly their N-terminally biotinylated peptide compounds (BP4 and BP21), inhibited PAF-induced rat paw oedema dose dependently and markedly, and showed sufficient inhibition of the oedema even at doses 150-300 times less than the doses of PAF antagonists. These results provide evidence that direct binding of N-terminally biotinylated peptide compounds derived from Asp-hemolysin to PAF and lyso-PAF leads to a dramatic inhibition of the bioactivities of PAF, both in vitro and in vivo, and strongly suggesting that these compounds may be useful as a novel type of anti-inflammatory drug for the treatment of several inflammatory diseases caused by PAF.
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Affiliation(s)
- Akira Sato
- Faculty of Pharmacy, Iwaki Meisei University, 5-5-1 Chuodai-Iino, Iwaki, Fukushima, 970-8551 Japan.
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Chen CH, Lu J, Chen SH, Huang RY, Yilmaz HR, Dong J, Elayda MA, Dixon RAF, Yang CY. Effects of electronegative VLDL on endothelium damage in metabolic syndrome. Diabetes Care 2012; 35:648-53. [PMID: 22279032 PMCID: PMC3322679 DOI: 10.2337/dc11-1623] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/23/2011] [Accepted: 11/18/2011] [Indexed: 02/03/2023]
Abstract
OBJECTIVE Biochemical heterogeneity governs functional disparities among lipoproteins. We examined charge-defined VLDL subfractions in metabolic syndrome (MetS) to determine whether their increased electronegativity is associated with increased cytotoxicity and whether high concentrations of highly electronegative subfractions render VLDL harmful to the vascular endothelium. RESEARCH DESIGN AND METHODS Plasma VLDL of normal individuals (control subjects) (n = 13) and of those with MetS (n = 13) was resolved into subfractions with increasing negative charge (V1-V5) by anion-exchange chromatography. Human aortic endothelial cells were treated with V1-V5 or unfractionated VLDL. RESULTS Compared with the control subjects, individuals with MetS had a significantly higher percentage of V5 VLDL (V5/VLDL%) (34 ± 20 vs. 39 ± 11%, respectively; P < 0.05) and plasma V5 concentration ([V5]) (5.5 ± 4.4 vs. 15.2 ± 8.5 mg/dL, respectively; P < 0.001). Apolipoprotein (apo)B100 levels decreased and apoC levels increased from V1 to V5, indicating that V5 is apoC-rich VLDL. Regression analyses of all 26 individuals showed that [V5] was positively correlated with total cholesterol (P = 0.016), triglyceride (P < 0.000001), and V5/VLDL% (P = 0.002). Fasting plasma glucose, but not waist circumference, exhibited a positive trend (P = 0.058); plasma HDL cholesterol exhibited a weak inverse trend (P = 0.138). V5 (10 μg/mL) induced apoptosis in ~50% of endothelial cells in 24 h. V5 was the most rapidly (<15 min) internalized subfraction and induced the production of reactive oxygen species (ROS) in endothelial cells after 20 min. Unfractionated MetS VLDL, but not control VLDL, also induced ROS production and endothelial cell apoptosis. CONCLUSIONS In populations with increased risk of diabetes, the vascular endothelium is constantly exposed to VLDL that contains a high proportion of V5. The potential impact of V5-rich VLDL warrants further investigation.
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Hung ND, Sok DE, Kim MR. Prevention of 1-palmitoyl lysophosphatidylcholine-induced inflammation by polyunsaturated acyl lysophosphatidylcholine. Inflamm Res 2012; 61:473-83. [PMID: 22252240 DOI: 10.1007/s00011-012-0434-x] [Citation(s) in RCA: 78] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2011] [Revised: 12/29/2011] [Accepted: 12/30/2011] [Indexed: 12/31/2022] Open
Abstract
OBJECTIVE The aim of this study was to examine the inflammation induced by saturated acyl lysophosphatidylcholine (LPC) in vivo and to investigate whether it could be attenuated by the action of polyunsaturated acyl lysophosphatidylcholines (LPCs), which are known as anti-inflammatory lipid mediators. METHODS First, saturated acyl LPC was administered intraperitoneally (i.p.) to mice and the inflammatory profile was extensively characterized. Subsequently, the preventive effect of polyunsaturated acyl LPCs, i.p. administered 30 min after saturated acyl LPC, was evaluated by measuring indices of inflammation such as leukocyte migration, plasma leakage, and eicosanoid or cytokine formation by light microscopy, Evans blue dye as indicator, and enzyme-linked immunosorbent assay, respectively. RESULTS Saturated acyl LPCs as LPC16:0 (100 mg/kg, i.p.) proved to be an effective inflammation inducer which causes a significant increase in plasma leakage, leukocyte migration into peritoneum and elevation of pro-inflammatory mediators. Interestingly, LPC20:4 and LPC22:6 (50 and 150 μg/kg) significantly nullified LPC16:0-induced inflammation. The anti-inflammatory effects of LPC20:4 and LPC22:6 were related to down-regulation of leukocyte extravasation, plasma leakage, and formation of pro-inflammatory mediators (IL-5, IL-6, NO, 12-HETE and PGE(2)) stimulated by LPC16:0, and up-regulation of anti-inflammatory mediators (IL-4 and IL-10). CONCLUSION These results indicated that the pro-inflammatory activity of saturated acyl LPCs could be antagonized by the actions of polyunsaturated acyl LPCs, anti-inflammatory lipid mediators.
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Affiliation(s)
- Nguyen Dang Hung
- College of Pharmacy, Chungnam National University, Yuseong-Gu, Gungdong, Daejeon, Korea.
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Itabashi Y. Development and application of chromatographic methods for glycerolipid analysis. CHROMATOGRAPHY 2011. [DOI: 10.15583/jpchrom.2011.005] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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Lysophosphatidylcholines activate G2A inducing G(αi)₋₁-/G(αq/)₁₁- Ca²(+) flux, G(βγ)-Hck activation and clathrin/β-arrestin-1/GRK6 recruitment in PMNs. Biochem J 2010; 432:35-45. [PMID: 20799926 DOI: 10.1042/bj20091087] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Lyso-PCs (lysophosphatidylcholines) are a mixture of lipids that accumulate during storage of cellular blood components, have been implicated in TRALI (transfusion-related acute lung injury) and directly affect the physiology of neutrophils [PMNs (polymorphonuclear leucocytes)]. Because the G2A receptor, expressed on PMNs, has been reported to recognize lyso-PCs, we hypothesize that lyso-PC activation of G2A causes the increases in cytosolic Ca²(+) via release of G(α) and G(βγ) subunits, kinase activation, and the recruitment of clathrin, β-arrestin-1 and GRK6 (G-protein receptor kinase 6) to G2A for signal transduction. PMNs were isolated by standard techniques, primed with lyso-PCs for 5-180 s, and lysed for Western blot analysis, immunoprecipitation or subcellular fractionation, or fixed and smeared on to slides for digital microscopy. The results demonstrated that lyso-PCs cause rapid activation of the G2A receptor through S-phosphorylation and internalization resulting in G(αi)₋₁ and G(αq/)₁₁ release leading to increases in cytosolic Ca²(+), which was inhibited by an antibody to G2A or intracellular neutralization of these subunits. Lyso-PCs also caused the release of the G(βγ) subunit which demonstrated a physical interaction (FRET+) with activated Hck (haemopoietic cell kinase; Tyr⁴¹¹). Moreover, G2A recruited clathrin, β-arrestin-1 and GRK6: clathrin is important for signal transduction, GRK6 for receptor de-sensitization, and β-arrestin-1 both propagates and terminates signals. We conclude that lyso-PC activation of G2A caused release of G(αi)₋₁, G(αq/)₁₁ and G(βγ), resulting in cytosolic Ca²(+) flux, Hck activation, and recruitment of clathrin, β-arrestin-1 and GRK6.
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Riederer M, Ojala PJ, Hrzenjak A, Graier WF, Malli R, Tritscher M, Hermansson M, Watzer B, Schweer H, Desoye G, Heinemann A, Frank S. Acyl chain-dependent effect of lysophosphatidylcholine on endothelial prostacyclin production. J Lipid Res 2010; 51:2957-66. [PMID: 20610733 DOI: 10.1194/jlr.m006536] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Previously we identified palmitoyl-lysophosphatidylcholine (16:0 LPC), linoleoyl-LPC (18:2 LPC), arachidonoyl-LPC (20:4 LPC), and oleoyl-LPC (18:1 LPC) as the most prominent LPC species generated by the action of endothelial lipase (EL) on high-density lipoprotein. In the present study, the impact of those LPC on prostacyclin (PGI(2)) production was examined in vitro in primary human aortic endothelial cells (HAEC) and in vivo in mice. Although 18:2 LPC was inactive, 16:0, 18:1, and 20:4 LPC induced PGI(2) production in HAEC by 1.4-, 3-, and 8.3-fold, respectively. LPC-elicited 6-keto PGF1α formation depended on both cyclooxygenase (COX)-1 and COX-2 and on the activity of cytosolic phospholipase type IVA (cPLA2). The LPC-induced, cPLA2-dependent (14)C-arachidonic acid (AA) release was increased 4.5-fold with 16:0, 2-fold with 18:1, and 2.7-fold with 20:4 LPC, respectively, and related to the ability of LPC to increase cytosolic Ca(2+) concentration. In vivo, LPC increased 6-keto PGF(1α) concentration in mouse plasma with a similar order of potency as found in HAEC. Our results indicate that the tested LPC species are capable of eliciting production of PGI(2), whereby the efficacy and the relative contribution of underlying mechanisms are strongly related to acyl-chain length and degree of saturation.
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Affiliation(s)
- Monika Riederer
- Institute of Molecular Biology and Biochemistry, University of Helsinki, Helsinki, Finland
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The role of lipoprotein-associated phospholipase A2 in atherosclerosis may depend on its lipoprotein carrier in plasma. Biochim Biophys Acta Mol Cell Biol Lipids 2009; 1791:327-38. [PMID: 19272461 DOI: 10.1016/j.bbalip.2009.02.015] [Citation(s) in RCA: 117] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2008] [Revised: 02/06/2009] [Accepted: 02/19/2009] [Indexed: 01/28/2023]
Abstract
Platelet-activating factor (PAF) acetylhydrolase exhibits a Ca(2+)-independent phospholipase A2 activity and degrades PAFas well as oxidized phospholipids (oxPL). Such phospholipids are accumulated in the artery wall and may play key roles in vascular inflammation and atherosclerosis. PAF-acetylhydrolase in plasma is complexed to lipoproteins; thus it is also referred to as lipoprotein-associated phospholipase A2 (Lp-PLA2). Lp-PLA2 is primarily associated with low-density lipoprotein (LDL), whereas a small proportion of circulating enzyme activity is also associated with high-density lipoprotein (HDL). The majority of the LDL-associated Lp-PLA2 (LDL-Lp-PLA2) activity is bound to atherogenic small-dense LDL particles and it is a potential marker of these particles in plasma. The distribution of Lp-PLA2 between LDL and HDL is altered in various types of dyslipidemias. It can be also influenced by the presence of lipoprotein (a) [Lp(a)] when plasma levels of this lipoprotein exceed 30 mg/dl. Several lines of evidence suggest that the role of plasma Lp-PLA2 in atherosclerosis may depend on the type of lipoprotein particle with which this enzyme is associated. In this regard, data from large Caucasian population studies have shown an independent association between the plasma Lp-PLA2 levels (which are mainly influenced by the levels of LDL-Lp-PLA2) and the risk of future cardiovascular events. On the contrary, several lines of evidence suggest that HDL-associated Lp-PLA2 may substantially contribute to the HDL antiatherogenic activities. Recent studies have provided evidence that oxPL are preferentially sequestered on Lp(a) thus subjected to degradation by the Lp(a)-associated Lp-PLA2. These data suggest that Lp(a) may be a potential scavenger of oxPL and provide new insights into the functional role of Lp(a) and the Lp(a)-associated Lp-PLA2 in normal physiology as well as in inflammation and atherosclerosis. The present review is focused on recent advances concerning the Lp-PLA2 structural characteristics, the molecular basis of the enzyme association with distinct lipoprotein subspecies, as well as the potential role of Lp-PLA2 associated with different lipoprotein classes in atherosclerosis and cardiovascular disease.
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Schmitz G, Ruebsaamen K. Metabolism and atherogenic disease association of lysophosphatidylcholine. Atherosclerosis 2009; 208:10-8. [PMID: 19570538 DOI: 10.1016/j.atherosclerosis.2009.05.029] [Citation(s) in RCA: 247] [Impact Index Per Article: 16.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/06/2008] [Revised: 04/27/2009] [Accepted: 05/25/2009] [Indexed: 10/20/2022]
Abstract
Lysophosphatidylcholine (LPC) is a major plasma lipid that has been recognized as an important cell signalling molecule produced under physiological conditions by the action of phospholipase A(2) on phosphatidylcholine. LPC transports glycerophospholipid components such as fatty acids, phosphatidylglycerol and choline between tissues. LPC is a ligand for specific G protein-coupled signalling receptors and activates several second messengers. LPC is also a major phospholipid component of oxidized low-density lipoproteins (Ox-LDL) and is implicated as a critical factor in the atherogenic activity of Ox-LDL. Hence, LPC plays an important role in atherosclerosis and acute and chronic inflammation. In this review we focus in some detail on LPC function, biochemical pathways, sources and signal-transduction system. Moreover, we outline the detection of LPC by mass spectrometry which is currently the best method for accurate and simultaneous analysis of each individual LPC species and reveal the pathophysiological implication of LPC which makes it an interesting target for biomarker and drug development regarding atherosclerosis and cardiovascular disorders.
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Affiliation(s)
- Gerd Schmitz
- Institute for Clinical Chemistry and Laboratory Medicine, University of Regensburg, Regensburg, Germany.
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PAF-acetylhydrolase expressed during megakaryocyte differentiation inactivates PAF-like lipids. Blood 2009; 113:6699-706. [PMID: 19395675 DOI: 10.1182/blood-2008-11-186312] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Platelet activating factor (PAF) and PAF-like lipids induce inflammatory responses in target cells. These lipid mediators are inactivated by PAF-acetylhydrolase (PAF-AH). The PAF signaling system affects the growth of hematopoietic CD34(+) cells, but roles for PAF-AH in this process are unknown. Here, we investigated PAF-AH function during megakaryopoiesis and found that human CD34(+) cells accumulate this enzymatic activity as they differentiate toward megakaryocytes, consistent with the expression of mRNA and protein for the plasma PAF-AH isoform. Inhibition of endogenous PAF-AH activity in differentiated megakaryocytes increased formation of lipid mediators that signaled the PAF receptor (PAFR) in fully differentiated human cells such as neutrophils, as well as megakaryocytes themselves. PAF-AH also controlled megakaryocyte alpha(IIb)beta(3)-dependent adhesion, cell spreading, and mobility that relied on signaling through the PAFR. Together these data suggest that megakaryocytes generate PAF-AH to modulate the accumulation of intracellular phospholipid mediators that may detrimentally affect megakaryocyte development and function.
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Linkous A, Geng L, Lyshchik A, Hallahan DE, Yazlovitskaya EM. Cytosolic phospholipase A2: targeting cancer through the tumor vasculature. Clin Cancer Res 2009; 15:1635-44. [PMID: 19240173 DOI: 10.1158/1078-0432.ccr-08-1905] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
PURPOSE In vascular endothelial cells, low doses of ionizing radiation trigger the immediate activation of cytosolic phospholipase A2 (cPLA2). This event initiates prosurvival signaling that could be responsible for radioresistance of tumor vasculature. Thus, the development of radiosensitizers targeting these survival pathways may enhance tumor response to radiation therapy. Arachidonyltrifluoromethyl Ketone (AACOCF3), a specific cPLA2 inhibitor, was studied as a potential radiosensitizer. EXPERIMENTAL DESIGN Vascular endothelial cells (3B11 and MPMEC) and lung tumor cells (LLC and H460) were treated with 1 micromol/L AACOCF3 for 30 minutes prior to irradiation. Treatment response was evaluated by clonogenic survival, activation of extracellular signal-regulated kinase 1/2 (ERK1/2), tubule formation, and migration assays. For in vivo experiments, mice with LLC or H460 tumors in the hind limbs were treated for 5 consecutive days with 10 mg/kg AACOCF3 administered daily 30 minutes prior to irradiation. Treatment response was assessed by tumor growth delay, Power Doppler Sonography, and immunohistochemistry. RESULTS In cell culture experiments, inhibition of cPLA2 with AACOCF3 prevented radiation-induced activation of ERK1/2 and decreased clonogenic survival of irradiated vascular endothelial cells but not the lung tumor cells. Treatment with AACOCF3 also attenuated tubule formation and migration in irradiated vascular endothelial cells. In both tumor mouse models, treatment with AACOCF3 prior to irradiation significantly suppressed tumor growth and decreased overall tumor blood flow and vascularity. Increased apoptosis in both tumor cells and tumor vascular endothelium was determined as a possible mechanism of the observed effect. CONCLUSION These findings identify cPLA2 as a novel molecular target for tumor sensitization to radiation therapy through the tumor vasculature.
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Affiliation(s)
- Amanda Linkous
- Department of Radiation Oncology, Vanderbilt-Ingram Cancer Center, Vanderbilt University School of Medicine, Nashville, Tennessee 37232-5671, USA
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Welch EJ, Naikawadi RP, Li Z, Lin P, Ishii S, Shimizu T, Tiruppathi C, Du X, Subbaiah PV, Ye RD. Opposing effects of platelet-activating factor and lyso-platelet-activating factor on neutrophil and platelet activation. Mol Pharmacol 2008; 75:227-34. [PMID: 18931035 DOI: 10.1124/mol.108.051003] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Platelet-activating factor (PAF) is a potent, bioactive phospholipid that acts on multiple cells and tissues through its G protein-coupled receptor (GPCR). PAF is not stored but is rapidly generated via enzymatic acetylation of the precursor 1-O-hexadecyl-2-hydroxy-sn-glycero-3-phosphocholine (lysoPAF). The bioactivity of PAF is effectively and tightly regulated by PAF acetylhydrolases, which convert PAF back to lysoPAF. Previous studies report that lysoPAF is an inactive precursor and metabolite of PAF. However, lysoPAF has not been carefully studied in its own context. Here we report that lysoPAF has an opposing effect of PAF in the activation of neutrophils and platelets. Whereas PAF potentiates neutrophil NADPH oxidase activation, lysoPAF dose-dependently inhibits this function. Inhibition by lysoPAF is not affected by the use of a PAF receptor antagonist or genetic deletion of the PAF receptor gene. The mechanism of lysoPAF-mediated inhibition of neutrophils involves an elevation in the intracellular cAMP level, and pharmacological blockade of adenylyl cyclase completely reverses the inhibitory effect of lysoPAF. In addition, lysoPAF increases intracellular cAMP levels in platelets and inhibits thrombin-induced platelet aggregation, which can be reversed by inhibition of protein kinase A. These findings identify lysoPAF as a bioactive lipid with opposing functions of PAF and suggest a novel and intrinsic regulatory mechanism for balance of the potent activity of PAF.
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Affiliation(s)
- Emily J Welch
- Department of Pharmacology, University of Illinois College of Medicine, Chicago, IL 60612, USA
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Olofsson KE, Andersson L, Nilsson J, Björkbacka H. Nanomolar concentrations of lysophosphatidylcholine recruit monocytes and induce pro-inflammatory cytokine production in macrophages. Biochem Biophys Res Commun 2008; 370:348-52. [PMID: 18371300 DOI: 10.1016/j.bbrc.2008.03.087] [Citation(s) in RCA: 71] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2008] [Accepted: 03/19/2008] [Indexed: 01/01/2023]
Abstract
Lysophosphatidylcholine (LPC) has been attributed a pro-inflammatory role in atherosclerosis. Cell culture studies have identified stimulation of cytokine expression and chemotaxis by micromolar (muM) concentrations of LPC. In the present study we have investigated if LPC, in similarity with many other lipid mediators, has pro-inflammatory effects also at nanomolar (nM) concentrations. Cultured mouse bone marrow derived and RAW264.7 macrophages exposed to LPC demonstrated two peaks of increased MIP-2 release and mRNA expression; one at 0.1-10nM and another at muM concentrations. Both concentration ranges of LPC were also found to stimulate THP-1 monocyte chemotaxis. However, stimulation of the cells with muM concentrations of LPC may cause cell injury as increased release of lactate dehydrogenase was observed. Our findings demonstrate two peaks of LPC-induced pro-inflammatory activity, one in the nM and one in the muM range, and indicate that the latter may involve a stress response to lipid cytotoxicity.
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Affiliation(s)
- Katarina E Olofsson
- Department of Clinical Sciences, Experimental Cardiovascular Research, CRC Lund University, Building 91:12, Malmö University Hospital, Entrance 72, SE-205 02 Malmö, Sweden
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Takenouchi T, Sato M, Kitani H. Lysophosphatidylcholine potentiates Ca2+ influx, pore formation and p44/42 MAP kinase phosphorylation mediated by P2X7 receptor activation in mouse microglial cells. J Neurochem 2007; 102:1518-1532. [PMID: 17437542 DOI: 10.1111/j.1471-4159.2007.04570.x] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
The P2X7 receptor (P2X7R) is an ATP-gated ion channel highly expressed in microglia. P2X7R plays important roles in inflammatory responses in the brain. However, little is known about the mechanisms regulating its functions in microglia. Lysophosphatidylcholine (LPC), an inflammatory phospholipid that promotes microglial activation, may have some relevance to P2X7R signaling in terms of microglial function. In this study, we examined its effects on P2X7R signaling in a mouse microglial cell line (MG6) and primary microglia. LPC facilitated the sustained increase in the intracellular Ca(2+) concentration ([Ca(2+)](i)) through P2X7R channels activated by ATP or BzATP. The potentiated increase in [Ca(2+)](i) was actually inhibited by P2X7R antagonists, brilliant blue G and oxidized ATP. The potentiating effect of LPC was not observed with P2Y receptor systems, which are also expressed in MG6 cells. G2A, a receptor for LPC, was expressed in MG6 cells, but not involved in the facilitating effect of LPC on the P2X7R-mediated change in [Ca(2+)](i). Furthermore, LPC enhanced the P2X7R-associated formation of membrane pores and the activation of p44/42 mitogen-activated protein kinase. These results suggest that LPC may regulate microglial functions in the brain by enhancing the sensitivity of P2X7R.
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Affiliation(s)
- Takato Takenouchi
- Transgenic Animal Research Center, National Institute of Agrobiological Sciences, Ohwashi, Tsukuba, Ibaraki, Japan
| | - Mitsuru Sato
- Transgenic Animal Research Center, National Institute of Agrobiological Sciences, Ohwashi, Tsukuba, Ibaraki, Japan
| | - Hiroshi Kitani
- Transgenic Animal Research Center, National Institute of Agrobiological Sciences, Ohwashi, Tsukuba, Ibaraki, Japan
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Vasques E, Almeida ALF, Noya V, D'Alegria B, Marathe G, McIntyre TM, Tibiriçá E, Bozza PT, Silva AR, Castro-Faria-Neto HC. Impairment of endothelium-dependent aorta relaxation by phospholipid components of oxidized low-density lipoprotein. ACTA ACUST UNITED AC 2006; 13:1-8. [PMID: 16885061 DOI: 10.1080/10623320600659948] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Abstract
Oxidized low-density lipoprotein (LDL) is a major component in the pathophysiology of atherosclerosis and plays a role in the changes of vascular reactivity observed in this disease. Herein the authors investigate the potential involvement of platelet-activating factor (PAF)-like phospholipid components of oxidized LDL in rabbit aorta reactivity. Aortic rings were precontracted with noradrenaline (0.5 microM) and relaxation was induced by subsequent stimulation with sequential additions of acetylcholine (1 nM to 3 microM). High-performance liquid chromatography (HPLC) fractions (6- and 7-min) obtained from phospholipids extracted from oxidized LDL inhibited relaxation evoked by acetylcholine, but not the relaxation induced by sodium nitroprusside. This effect was not antagonized either by incubation of the fractions with PAF acetylhydrolase or by incubation of the aortic rings with a PAF receptor antagonist. Authentic PAF or C4-PAF, a PAF mimetic previously found in fractions 6 and 7 did not inhibit acetylcholine-induced relaxation. In contrast, lyso-PAF inhibited acetylcholine, but not sodium nitroprusside-induced relaxation. The authors conclude that phospholipids of oxidized LDL impair vascular reactivity to endothelium-dependent agonists. This effect is not due to oxidatively generated proinflammatory PAF mimetics, but rather to a metabolite of these phospholipids, lysoPAF.
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Affiliation(s)
- Eunice Vasques
- Laboratório de Imunofarmacologia Neurocardiovascular, Departamento de Fisiologia e Farmacodinâmica, IOC, Fundação Oswaldo Cruz, Rio de Janeiro, RJ, Brazil
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Unno N, Sakaguchi T, Nakamura T, Yamamoto N, Sugatani J, Miwa M, Konno H. A single nucleotide polymorphism in the plasma PAF acetylhydrolase gene and risk of atherosclerosis in Japanese patients with peripheral artery occlusive disease. J Surg Res 2006; 134:36-43. [PMID: 16650870 DOI: 10.1016/j.jss.2006.02.058] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2006] [Revised: 02/20/2006] [Accepted: 02/27/2006] [Indexed: 11/20/2022]
Abstract
BACKGROUND Plasma PAF-acetylhydrolase (PAF-AH) gene polymorphisms (G994 --> T in exon 9) and the resulting deficiency of enzyme activity were identified in the Japanese population. The objective of this study was to assess the joint effect of the polymorphism and hypercholesterolemia on risk of atherosclerosis. METHODS AND RESULTS We performed a case-control study including 150 patients who underwent operation for peripheral arterial occlusive disease (PAOD) and 158 controls matched for age and sex. Genomic DNA was analyzed for the mutant allele by a specific polymerase-chain reaction. Plasma PAF-AH activity was measured in both groups. The patients with multiple atherosclerotic diseases showed higher levels of PAF-AH activities than the patients with only peripheral artery occlusive disease among normal genotypes. PAOD patients were assessed either with or without polymorphism or hypercholesterolemia in regard to accompanying coronary artery disease or stroke. The prevalence of the polymorphism was significantly more frequent in the patients with PAOD. The plasma PAF-AH activity was correlated with total cholesterol and LDL level, and inversely related with HDL in normal genotype (GG) PAOD patients. However, neither the correlation nor the inverse relation was found in patients with the polymorphism. Patients with both hypercholesterolemia and the polymorphisms revealed a relative risk for other atherosclerotic disease of 11.5 (6.0-40.3) compared with normal genotype and normal lipid level. CONCLUSION The plasma PAF-AH gene polymorphism and hypercholesterolemia may interact and increase the risk of atherosclerosis.
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Affiliation(s)
- Naoki Unno
- Second Department of Surgery, Hamamatsu University School of Medicine, Hamamatsu, Japan.
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Marathe GK, Johnson C, Billings SD, Southall MD, Pei Y, Spandau D, Murphy RC, Zimmerman GA, McIntyre TM, Travers JB. Ultraviolet B Radiation Generates Platelet-activating Factor-like Phospholipids underlying Cutaneous Damage. J Biol Chem 2005; 280:35448-57. [PMID: 16115894 DOI: 10.1074/jbc.m503811200] [Citation(s) in RCA: 80] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Ultraviolet B light (UVB) causes cutaneous inflammation and cell death, but the agents responsible are not defined. These studies examined the role of the platelet-activating factor (PAF) signaling system in UVB-mediated effects. Expression of the PAF receptor in the PAF receptor-negative epidermoid cell line KB augmented apoptosis in response to UVB irradiation. Overexpression of the PAF receptor in primary human keratinocytes also enhanced UVB-mediated apoptosis in vitro, and it enhanced apoptosis in an in vivo model of human keratinocytes grafted onto severe combined immune-deficient (SCID) mice. To define the mechanism by which UVB activates the PAF receptor, we used mass spectrometry to demonstrate significant amounts of the C4 PAF analogs 1-alkyl-2-(butanoyl and butenoyl)-sn-glycero-3-phosphocholine, as well as native PAF in an epidermal cell line after UVB irradiation. Supplementing the cells with the precursor phospholipid 1-hexadecyl-2-arachidonoyl-sn-glycero-3-phosphocholine (HAPC) increased the amount of C4 PAF analogs recovered after UVB exposure. We irradiated HAPC directly and found, even in the absence of a photosensitizer, fragmentation to C4-PAF receptor ligands. We conclude UVB photo-oxidizes cellular phospholipids, creating PAF analogs that stimulate the PAF receptor to induce further PAF synthesis and apoptosis. PAF signaling may participate in the cutaneous inflammation that occurs during photo-aggravated dermatoses.
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Affiliation(s)
- Gopal K Marathe
- Human Molecular Biology and Genetics Program, University of Utah, Salt Lake City 84112-5330, USA.
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Lin P, Welch EJ, Gao XP, Malik AB, Ye RD. Lysophosphatidylcholine modulates neutrophil oxidant production through elevation of cyclic AMP. THE JOURNAL OF IMMUNOLOGY 2005; 174:2981-9. [PMID: 15728511 DOI: 10.4049/jimmunol.174.5.2981] [Citation(s) in RCA: 70] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Lysophosphatidylcholine (LPC) is an oxidized phospholipid present in micromolar concentrations in blood and inflamed tissues. The effects of LPC on neutrophil functions remain incompletely understood, because conflicting reports exist for its stimulatory and inhibitory roles. We report in this study that LPC inhibits superoxide generation in fMLP- and PMA-stimulated neutrophils without affecting fMLP-induced Ca(2+) mobilization and cell viability. This effect was observed with LPC dissolved in ethanol, but not with LPC stock solutions prepared in water or in BSA-containing aqueous solution with sonication. Under the same experimental conditions, platelet-activating factor primed neutrophils for superoxide generation. The inhibitory effect of LPC was observed within 30 s after its application and was maximal at LPC concentrations between 0.1 and 1 muM. Inhibition of superoxide generation was accompanied by a 2.5-fold increase in the intracellular cAMP concentration. In addition, LPC reduced fMLP-stimulated phosphorylation of ERK and Akt and membrane translocation of p67(phox) and p47(phox). The protein kinase A inhibitors H-89 and adenosine 3'5'-cyclic monophosphorothioate Rp-isomer (Rp-cAMP) partially restored superoxide production in LPC-treated neutrophils, indicating involvement of protein kinase A in LPC-mediated inhibition. Using an ex vivo mouse lung perfusion model that measures lung weight change and capillary filtration coefficient, we found that LPC prevented lung vascular injury mediated by fMLP-activated neutrophils. Taken together, these results suggest that LPC-induced elevation of intracellular cAMP is partially responsible for its inhibition of neutrophil NADPH oxidase activation. A similar mechanism of inhibition may be used for the control of neutrophil-mediated tissue injury.
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Affiliation(s)
- Phoebe Lin
- Department of Pharmacology, University of Illinois College of Medicine, Chicago, IL 60612, USA
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Abstract
PURPOSE OF REVIEW This review provides a brief update on the involvement of major phospholipid mediators, with the emphasis on platelet-activating factor and its analogues generated upon the oxidation of lipoproteins in vascular pathology, including atherogenesis. RECENT FINDINGS Phospholipid mediators are produced during inflammation by various enzymes, mostly from pre-existing membrane phospholipids, and trigger cellular signaling via G-coupled receptors. A short description of lysophosphatidic acid, lysophosphocholine and sphingosine-1 phosphate receptors and their actions is given, but attention is focused mainly on platelet-activating factor and its analogues. The majority of these mediators participate in leukocyte adhesiveness to the endothelium, leukocyte transmigration into the vessel wall and the subsequent formation of various chemokines leading to foam cell formation and smooth muscle cell proliferation and dedifferentiation. Platelet-activating factor and platelet-activating factor-like phospholipids are degraded in plasma by the lipoprotein-bound enzyme of myeloid origin, PAF-acetylhydrolase, also known as LDL-PLA2. Although the overexpression of PAF-acetylhydrolase shows marked anti-atherogenic properties in animal models, epidemiological data in the Caucasian population have demonstrated that its level might be a risk factor for cardiovascular disease. Recent genetic studies have shown, however, that the A379V polymorphism of this gene, responsible for slightly higher enzymatic activity, exerts a protective effect, probably by modifying the enzyme function towards a less atherogenic form. SUMMARY Phospholipid-borne mediators are certainly key players in inflammation and thus in atherosclerosis. The generation of such biologically active molecules is possibly dependent on nutritional habits and the availability of antioxidants, including enzymes protective against oxidative damage, including PAF-acetylhydrolase.
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Affiliation(s)
- Ewa Ninio
- INSERM U525, IFR14 Coeur Muscle Vaisseaux and Université P.M. Curie, Faculté de Médecine, Paris, France.
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Rosseto R, Bibak N, Hajdu J. A new approach to the synthesis of lysophospholipids: preparation of lysophosphatidic acid and lysophosphatidylcholine from p-nitrophenyl glycerate. Tetrahedron Lett 2004. [DOI: 10.1016/j.tetlet.2004.07.161] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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40
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Stafforini DM, McIntyre TM, Zimmerman GA, Prescott SM. Platelet-activating factor, a pleiotrophic mediator of physiological and pathological processes. Crit Rev Clin Lab Sci 2004; 40:643-72. [PMID: 14708958 DOI: 10.1080/714037693] [Citation(s) in RCA: 155] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Platelet-activating factor (PAF) is a potent proinflammatory phospholipid with diverse pathological and physiological effects. This bioactive phospholipid mediates processes as diverse as wound healing, physiological inflammation, apoptosis, angiogenesis, reproduction and long-term potentiation. Recent progress has demonstrated the participation of MAP kinase signaling pathways as modulators of the two critical enzymes, phospholipase A2 and acetyltransferase, involved in the remodeling pathway of PAF biosynthesis. The unregulated production of structural analogs of PAF by non-specific oxidative reactions has expanded this superfamily of signaling molecules to include "PAF-like" lipids whose mode of action is identical to that of authentic PAF. The action of members of this family is mediated by the PAF receptor, a G protein-coupled membrane-spanning molecule that can engage multiple signaling pathways in various cell types. Inappropriate activation of this signaling pathway is associated with many diseases in which inflammation is thought to be one of the underlying features. Inactivation of all members of the PAF superfamily occurs by a unique class of enzymes, the PAF acetylhydrolases, that have been characterized at the molecular level and that terminate signals initiated by both regulated and unregulated PAF production.
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Affiliation(s)
- Diana M Stafforini
- Huntsman Cancer Institute, University of Utah, Salt Lake City, Utah 84112-5550, USA.
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Abstract
PURPOSE OF REVIEW Although findings obtained from various studies are inconclusive in determining whether plasma platelet-activating factor acetylhydrolase, or lipoprotein-associated phospholipase A2, plays a proatherogenic or antiatherogenic role in atherosclerosis, many recent reviews appear to favor it as a risk factor for coronary artery disease. To provide a contrasting view, this review focuses on the enzyme's antiatherogenic and antiinflammatory properties. RECENT FINDINGS A recent report demonstrates that plasma platelet-activating factor acetylhydrolase activity increases in men and women with stable angina or acute coronary syndromes, supporting previously published data that plasma levels of the protein are independently and positively associated with the risk of coronary artery disease. In contrast, at least four lines of evidence indicate that the enzyme has strong antiatherogenic properties: (1) it inhibits the effects of LDL oxidation, (2) genetic deficiency of plasma levels constitutes a risk factor for vascular diseases including atherosclerosis, (3) adenoviral transfer of the protein reduces atherosclerosis in apolipoprotein E-deficient mice, and (4) pretreatment of an electronegative LDL subfraction isolated from hypercholesterolemic human plasma with a recombinant platelet-activating factor acetylhydrolase completely abolishes the proapoptotic effects of the electronegative LDL on vascular endothelial cells. Additionally, treatment with the recombinant product reduced mortality from severe sepsis in a phase IIb clinical trial. In an animal study, transfection of tumor cells with platelet-activating factor acetylhydrolase inhibited tumor growth at the site of implantation. SUMMARY Plasma platelet-activating factor acetylhydrolase becomes progressively activated as atherosclerosis progresses, but lines of evidence indicate that the enzyme possesses potent antiatherogenic and antiinflammatory properties. This raises the question of whether increased activity is a cause or a result of atherosclerosis and, consequently, whether inhibiting the enzyme's activities may decelerate or accelerate the progress of the disease.
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Affiliation(s)
- Chu-Huang Chen
- Department of Medicine, Section of Atherosclerosis and Lipoprotein Research, Baylor College of Medicine, 6565 Fannin, Mail Station A-601, Houston, TX 77030, USA.
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Chang MY, Tsoi C, Wight TN, Chait A. Lysophosphatidylcholine regulates synthesis of biglycan and the proteoglycan form of macrophage colony stimulating factor. Arterioscler Thromb Vasc Biol 2003; 23:809-15. [PMID: 12663372 DOI: 10.1161/01.atv.0000069208.20268.d0] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
OBJECTIVE We have shown that copper-oxidized LDL (Ox-LDL) regulates proteoglycan synthesis by arterial smooth muscle cells. Ox-LDL specifically upregulates biglycan expression while causing elongation of glycosaminoglycan chains on all of the major secreted proteoglycans (biglycan, decorin, and versican), resulting in enhanced lipoprotein-binding interactions. It is not known which component of Ox-LDL is responsible for these effects. This study investigated the ability of several bioactive components of Ox-LDL to regulate proteoglycan synthesis. METHODS AND RESULTS Those tested included 2 oxysterols (7-ketocholesterol and 7beta-hydroxycholesterol) and 2 lysolipids (lysophosphatidylcholine and lysophosphatidic acid) formed during LDL oxidation. 7-ketocholesterol, lysophosphatidylcholine, and lysophosphatidic acid all increased proteoglycan MWapp, which is correlated with chain elongation and enhanced lipoprotein-binding properties in vitro. Lysophosphatidylcholine mimics the ability of Ox-LDL to stimulate biglycan expression and also causes a marked induction of the core protein for the proteoglycan form of macrophage colony stimulating factor. CONCLUSIONS Multiple oxidized lipid molecules can modulate proteoglycan synthesis and may have important consequences to atherogenesis via processes that involve enhanced lipoprotein retention as well as the promotion of macrophage survival and differentiation.
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Affiliation(s)
- Mary Y Chang
- Department of Medicine, University of Washington, Seattle, Wash 98195-6426, USA.
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Chen CH, Jiang T, Yang JH, Jiang W, Lu J, Marathe GK, Pownall HJ, Ballantyne CM, McIntyre TM, Henry PD, Yang CY. Low-density lipoprotein in hypercholesterolemic human plasma induces vascular endothelial cell apoptosis by inhibiting fibroblast growth factor 2 transcription. Circulation 2003; 107:2102-8. [PMID: 12695302 DOI: 10.1161/01.cir.0000065220.70220.f7] [Citation(s) in RCA: 126] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
BACKGROUND Apoptosis of vascular endothelial cells (ECs) can be induced in vitro by experimentally modified LDL. Description of proapoptotic circulating lipoproteins may significantly enhance understanding of atherothrombosis pathophysiology. METHODS AND RESULTS Fast protein liquid chromatography of LDL samples from 7 asymptomatic, hypercholesterolemic patients yielded subfractions L1-L5 in increasing electronegativity. L4 and L5 were not detectable or collectible in normolipidemic samples. In bovine aortic EC cultures, L5 induced marked apoptosis and L4 had a mild effect, whereas hypercholesterolemic or normolipidemic L1-L3 had negligible effects. Compared with copper-oxidized LDL, L5 was only mildly oxidized, although its propensity to form conjugated dienes in response to copper exceeded that of other subfractions. L5-induced apoptosis was associated with suppressed fibroblast growth factor 2 (FGF-2) transcription, as assessed by nuclear run-on analysis. Degrading platelet-activating factor (PAF)-like lipids in L5 by a recombinant PAF acetylhydrolase prevented both FGF-2 downregulation and apoptosis. Furthermore, the ability of L5 lipid extract to induce calcium influx into neutrophils was lost after pretreatment of the extract with PAF acetylhydrolase. FGF-2 supplementation, PAF receptor (PAFR) blockade with WEB-2086, and inactivation of PAFR-coupled Gi protein with pertussis toxin all effectively attenuated L5-induced apoptosis. CONCLUSIONS Our findings indicate that a highly electronegative, mildly oxidized LDL subfraction present in human hypercholesterolemic but not normolipidemic plasma can induce apoptosis in cultured ECs. The evidence that a freshly isolated LDL species modulates transcription of FGF-2 may provide a physiological insight into the mechanism of vascular EC apoptosis in hypercholesterolemia.
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Affiliation(s)
- Chu-Huang Chen
- MS A-601, Department of Medicine, Baylor College of Medicine, 6565 Fannin St, Houston, Texas 77030, USA.
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Marathe GK, Zimmerman GA, McIntyre TM. Platelet-activating factor acetylhydrolase, and not paraoxonase-1, is the oxidized phospholipid hydrolase of high density lipoprotein particles. J Biol Chem 2003; 278:3937-47. [PMID: 12466264 DOI: 10.1074/jbc.m211126200] [Citation(s) in RCA: 143] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Paraoxonase-1 (PON1), an high density lipoprotein (HDL)-associated organophosphate triesterase, suppresses atherosclerosis in an unknown way. Purified PON1 protects lipoprotein particles from oxidative modification and hydrolyzes pro-atherogenic oxidized phospholipids and the inflammatory mediator platelet-activating factor (PAF). We find human PON1 acted as a phospholipase A(2) but not as a phospholipase C or D through cleavage of phosphodiester bonds as expected. PON1 requires divalent cations, but EDTA did not block the phospholipase A(2) activity of PON1. In contrast, a serine esterase inhibitor abolished phospholipase activity even though PON1 has no active-site serine residues. PAF acetylhydrolase, an oxidized phospholipid phospholipase A(2), is a serine esterase associated with specific HDL particles. Western blotting did not reveal detectable amounts of PAF acetylhydrolase in PON1 preparations, although very low amounts of PAF acetylhydrolase might still account for PON1 phospholipase A(2) activity. We revised the standard PON1 purification by first depleting HDL of PAF acetylhydrolase to find PON1 purified in this way no longer hydrolyzed oxidized phospholipids or PAF. Serum from a donor with an inactivating mutation in the PAF acetylhydrolase gene did not hydrolyze oxidized phospholipids or PAF, yet displayed full paraoxonase activity. We conclude that PAF acetylhydrolase is the sole phospholipase A(2) of HDL and that PON1 has no phospholipase activity toward PAF or pro-atherogenic oxidized phospholipids.
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Affiliation(s)
- Gopal K Marathe
- Human Molecular Biology and Genetics, University of Utah, Salt Lake City 84112-5330, USA
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Chaudhuri P, Colles SM, Damron DS, Graham LM. Lysophosphatidylcholine inhibits endothelial cell migration by increasing intracellular calcium and activating calpain. Arterioscler Thromb Vasc Biol 2003; 23:218-23. [PMID: 12588762 DOI: 10.1161/01.atv.0000052673.77316.01] [Citation(s) in RCA: 55] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
OBJECTIVE Endothelial cell (EC) migration, essential for reestablishing arterial integrity after vascular injury, is inhibited by oxidized LDL (oxLDL) and lysophosphatidylcholine (lysoPC) that are present in the arterial wall. We tested the hypothesis that a mechanism responsible for lysoPC-induced inhibition is increased intracellular free calcium concentration ([Ca(2+)](i)). METHODS AND RESULTS LysoPC, at concentrations that inhibit in vitro EC migration to 35% of control, increased [Ca(2+)](i) levels 3-fold. These effects of lysoPC were concentration dependent and reversible. LysoPC induced Ca(2+) influx within 10 minutes, and [Ca(2+)](i) remained elevated for 2 hours. The calcium ionophore A23187 also increased [Ca(2+)](i) and inhibited EC migration. Chelators of intracellular Ca(2+) (BAPTA/AM and EGTA/AM) and nonvoltage-sensitive channel blockers (lanthanum chloride and gadolinium chloride) blunted the lysoPC-induced [Ca(2+)](i) rise and partially preserved EC migration. After lysoPC treatment, calpain, a calcium-dependent cysteine protease, was activated, and cytoskeletal changes occurred. Calpain inhibitors (calpastatin, MDL28170, and calpeptin) added before lysoPC prevented cytoskeletal protein cleavage and preserved EC migration at 60% of control levels. CONCLUSIONS LysoPC increases [Ca(2+)](i). In turn, activating calpains that can alter the cytoskeleton are activated and EC migration is inhibited.
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Affiliation(s)
- Pinaki Chaudhuri
- Department of Biomedical Engineering, Lerner Research Institute, Cleveland Clinic Foundation, Cleveland, Ohio 44195, USA
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Pontsler AV, St Hilaire A, Marathe GK, Zimmerman GA, McIntyre TM. Cyclooxygenase-2 is induced in monocytes by peroxisome proliferator activated receptor gamma and oxidized alkyl phospholipids from oxidized low density lipoprotein. J Biol Chem 2002; 277:13029-36. [PMID: 11809750 DOI: 10.1074/jbc.m109546200] [Citation(s) in RCA: 84] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
Low density lipoprotein (LDL) oxidation and monocyte infiltration of the vessel wall underlie atherogenesis. These cells express cyclooxygenase-2, but the way oxidized LDL stimulates cyclooxygenase-2 transcription is unknown. Oxidized LDL, oxidatively fragmented phospholipids isolated from oxidized LDL, a synthetic oxidized alkylphospholipid (azPC) that is a potent peroxisome proliferator activated receptor (PPAR) gamma agonist, or the PPARgamma agonist rosiglitazone all induced cyclooxygenase-2 expression and enhanced prostaglandin E(2) (PGE(2)) secretion in primary human monocytes. The cyclooxygenase-2 inhibitor NS398 blocked PPARgamma-induced PGE(2) secretion. Phospholipase A(1) and A(2) digestion shows that oxidized alkylphospholipids, and not oxidized fatty acids, were the relevant agonists. The upstream PPAR-responsive element (PPRE) of cyclooxygenase-2 was required for induction of a luciferase reporter by oxidized phospholipids, azPC, and rosiglitazone, and a (COX-2 PPRE)(3)-luciferase reporter was responsive to these PPARgamma agonists. Circulating human monocytes do not contain PPARgamma, but PPARgamma was induced rapidly (<4 h) in monocytes upon ligation of surface ICAM-3, but not P-selectin glycoprotein-1 even though both interactions prime cytokine secretion. Cyclooxygenase-2 induction by oxidized phospholipids only occurred in monocytes containing PPARgamma. Thus PPARgamma was induced rapidly in primary monocytes by appropriate outside-in signaling, sensitizing them to previously undetectable agonists in oxidized LDL. Cyclooxygenase-2 and PGE(2) secretion are induced, not inhibited, by selective PPARgamma agonists that include oxidatively fragmented phospholipids in oxidized LDL.
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Affiliation(s)
- Aaron V Pontsler
- Department of Pathology, University of Utah, Salt Lake City, UT 84112, USA
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Marathe GK, Zimmerman GA, Prescott SM, McIntyre TM. Activation of vascular cells by PAF-like lipids in oxidized LDL. Vascul Pharmacol 2002; 38:193-200. [PMID: 12449015 DOI: 10.1016/s1537-1891(02)00169-6] [Citation(s) in RCA: 55] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
The components of inflammation, including macrophages, cytokines and lipid inflammatory mediators, have a role in atherosclerosis. A key lipid mediator in regulated, physiologic inflammation is platelet-activating factor (PAF). PAF activates cells, including monocytes, through a single molecularly characterized receptor, the PAF receptor (PAFR), at exceedingly low concentrations. The PAFR recognizes the short residue, an acetate residue, at the 2-position of the phospholipid, and this sharp specificity precludes receptor activation by other related phosphatidylcholines. Oxidation of low-density lipoproteins (LDLs) is an early and causal step in atherosclerosis that generates inflammatory compounds leading to foam cell formation. One class of oxidatively generated inflammatory compounds are phospholipids that structurally mimic PAF, the PAF-like lipids. Oxidation of LDLs fragments and derivatizes the fatty acid residues at the 2-position of the phosphatidylcholines that comprise the shell of LDLs, an event that allows certain oxidized phospholipids to interact with and activate the PAFR. We know that these products activate polymorphonuclear leukocytes, but because the function of the PAFR differs among cells, we do not know if monocytes or platelets themselves respond to PAF-like lipids. Here, we show that PAF-like lipids from oxidized LDLs are potent and serve as specific agonists for all cells that express the PAFR.
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Affiliation(s)
- Gopal K Marathe
- Department of Internal Medicine, Human Molecular Biology and Genetics Program, University of Utah, Salt Lake City, UT 84112, USA
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