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Putta P, Chaudhuri P, Guardia-Wolff R, Rosenbaum MA, Graham LM. iPLA2 inhibition blocks LysoPC-induced TRPC6 externalization and promotes Re-endothelialization of carotid injuries in hypercholesterolemic mice. Cell Calcium 2023; 112:102734. [PMID: 37030190 PMCID: PMC10234282 DOI: 10.1016/j.ceca.2023.102734] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2023] [Revised: 03/13/2023] [Accepted: 03/30/2023] [Indexed: 04/10/2023]
Abstract
Lipid oxidation products, including lysophosphatidylcholine (lysoPC), accumulate at the site of arterial injury after vascular interventions and hinder re-endothelization. LysoPC activates calcium-permeable channels, specifically canonical transient receptor potential 6 (TRPC6) channels that induce a sustained increase in intracellular calcium ion concentration [Ca2+]i and contribute to dysregulation of the endothelial cell (EC) cytoskeleton. Activation of TRPC6 leads to inhibition of EC migration in vitro and delayed re-endothelization of arterial injuries in vivo. Previously, we demonstrated the role of phospholipase A2 (PLA2), specifically calcium-independent PLA2 (iPLA2), in lysoPC-induced TRPC6 externalization and inhibition of EC migration in vitro. The ability of FKGK11, an iPLA2-specific pharmacological inhibitor, to block TRPC6 externalization and preserve EC migration was assessed in vitro and in a mouse model of carotid injury. Our data suggest that FKGK11 prevents lysoPC-induced PLA2 activity, blocks TRPC6 externalization, attenuates calcium influx, and partially preserves EC migration in vitro. Furthermore, FKGK11 promotes re-endothelization of an electrocautery carotid injury in hypercholesterolemic mice. FKGK11 has similar arterial healing effects in male and female mice on a high-fat diet. This study suggests that iPLA2 is a potential therapeutic target to attenuate calcium influx through TRPC6 channels and promote EC healing in cardiovascular patients undergoing angioplasty.
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Affiliation(s)
- Priya Putta
- Department of Biomedical Engineering, Cleveland Clinic, Cleveland, OH, 44195, United States.
| | - Pinaki Chaudhuri
- Research Service, Louis Stokes Cleveland Veterans Affairs Medical Center, Cleveland, OH, 44106, United States
| | - Rocio Guardia-Wolff
- Department of Biomedical Engineering, Cleveland Clinic, Cleveland, OH, 44195, United States
| | - Michael A Rosenbaum
- Surgical Service, Louis Stokes Cleveland Veterans Affairs Medical Center, Cleveland, OH, 44106, United States
| | - Linda M Graham
- Department of Biomedical Engineering, Cleveland Clinic, Cleveland, OH, 44195, United States; Department of Vascular Surgery, Cleveland Clinic, Cleveland, OH, 44195, United States
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2
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A metabolic associated fatty liver disease risk variant in MBOAT7 regulates toll like receptor induced outcomes. Nat Commun 2022; 13:7430. [PMID: 36473860 PMCID: PMC9726889 DOI: 10.1038/s41467-022-35158-9] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2021] [Accepted: 11/21/2022] [Indexed: 12/12/2022] Open
Abstract
The breakdown of toll-like receptor (TLR) tolerance results in tissue damage, and hyperactivation of the TLRs and subsequent inflammatory consequences have been implicated as risk factors for more severe forms of disease and poor outcomes from various diseases including COVID-19 and metabolic (dysfunction) associated fatty liver disease (MAFLD). Here we provide evidence that membrane bound O-acyltransferase domain containing 7 (MBOAT7) is a negative regulator of TLR signalling. MBOAT7 deficiency in macrophages as observed in patients with MAFLD and in COVID-19, alters membrane phospholipid composition. We demonstrate that this is associated with a redistribution of arachidonic acid toward proinflammatory eicosanoids, induction of endoplasmic reticulum stress, mitochondrial dysfunction, and remodelling of the accessible inflammatory-related chromatin landscape culminating in macrophage inflammatory responses to TLRs. Activation of MBOAT7 reverses these effects. These outcomes are further modulated by the MBOAT7 rs8736 (T) MAFLD risk variant. Our findings suggest that MBOAT7 can potentially be explored as a therapeutic target for diseases associated with dysregulation of the TLR signalling cascade.
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3
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Chen YF, Feng DD, Wu SH, Lu HY, Banu Pasha A, Permall DL, Chen JH, Sun ZY, Li BJ, Zhou H, Yang Y, Zhang XJ, Chen XQ. Promotion of Bronchopulmonary Dysplasia Progression Using Circular RNA circabcc4 via Facilitating PLA2G6 Expression by Sequestering miR-663a. Front Cell Dev Biol 2020; 8:585541. [PMID: 33195232 PMCID: PMC7654334 DOI: 10.3389/fcell.2020.585541] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2020] [Accepted: 10/08/2020] [Indexed: 12/04/2022] Open
Abstract
Circular RNA (circRNA) has been increasingly proven as a new type of promising therapeutic RNA molecule in a variety of human diseases. However, the role of circRNA in bronchopulmonary dysplasia (BPD) has not yet been elucidated. Here, a new circRNA circABCC4 was identified from the Agilent circRNA chip as a differentially expressed circRNA in BPD. The relationship between circABCC4 level and BPD clinicopathological characteristics was analyzed. The function of circABCC4 was evaluated by performing CCK-8 and apoptosis analysis in vitro and BPD model analysis in vivo. RNA immunoprecipitation (RIP), luciferase reporter and rescue experiments were used to elucidate the interaction between circABCC4 and miR-663a. Luciferase reporter assay and rescue experiments were used to elucidate the interaction between PLA2G6 and miR-663a. CircABCC4 and PLA2G6 levels were increased, while miR-663a levels were decreased in the BPD group, compared to the control group. MiR-663a inhibited apoptosis by repressing PLA2G6 expression, while circABCC4 enhanced the apoptosis and inhibited the proliferation of A549 cells by sponging miR-663a and increasing PLA2G6 expression. In conclusion, circABCC4 promotes the evolving of BPD by spongening miR-663a and up-regulating PLA2G6 expression, which makes circABCC4 an ideal molecular target for early diagnosis and intervention of BPD.
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Affiliation(s)
- Yu-Fei Chen
- Department of Pediatrics, The First Affliated Hospital of Nanjing Medical University, Nanjing, China
| | - Dan-Dan Feng
- Department of Pediatrics, The First Affliated Hospital of Nanjing Medical University, Nanjing, China
| | - Sheng-Hua Wu
- Department of Pediatrics, The First Affliated Hospital of Nanjing Medical University, Nanjing, China
| | - Hong-Yan Lu
- Department of Pediatrics, The Affiliated Hospital of Jiangsu University, Zhenjiang, China
| | - Asfia Banu Pasha
- Department of Pediatrics, The First Affliated Hospital of Nanjing Medical University, Nanjing, China
| | - Dhivya Lakshmi Permall
- Department of Pediatrics, The First Affliated Hospital of Nanjing Medical University, Nanjing, China
| | - Jia-He Chen
- Department of Pediatrics, The First Affliated Hospital of Nanjing Medical University, Nanjing, China
| | - Zhong-Yi Sun
- Department of Pediatrics, The First Affliated Hospital of Nanjing Medical University, Nanjing, China
| | - Bing-Jie Li
- Department of Pediatrics, The First Affliated Hospital of Nanjing Medical University, Nanjing, China
| | - Huan Zhou
- Department of Pediatrics, The First Affliated Hospital of Nanjing Medical University, Nanjing, China
| | - Yang Yang
- Department of Neonatology, Nanjing Children's Hospital of Nanjing Medical University, Nanjing, China
| | - Xiao-Jie Zhang
- Department of Pediatrics, The First Affliated Hospital of Nanjing Medical University, Nanjing, China
| | - Xiao-Qing Chen
- Department of Pediatrics, The First Affliated Hospital of Nanjing Medical University, Nanjing, China
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4
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Santiago-Fernandez C, Martin-Reyes F, Bautista R, Tome M, Gómez-Maldonado J, Gutierrez-Repiso C, Tinahones FJ, Garcia-Fuentes E, Garrido-Sánchez L. miRNA/Target Gene Profile of Endothelial Cells Treated with Human Triglyceride-Rich Lipoproteins Obtained after a High-Fat Meal with Extra-Virgin Olive Oil or Sunflower Oil. Mol Nutr Food Res 2020; 64:e2000221. [PMID: 32663360 DOI: 10.1002/mnfr.202000221] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2020] [Revised: 06/16/2020] [Indexed: 02/06/2023]
Abstract
SCOPE The effects of triglyceride-rich lipoproteins (TRLs) on the miRNA expression of endothelial cells, which are very involved in atherosclerosis, according to the type of diet are not known. METHODS AND RESULTS The differences between the effects of TRLs isolated from blood of subjects after a high-fat meal with extra-virgin olive oil (EVOO) and sunflower oil (SO) on the microRNA-Seq profile related to atherosclerosis in human umbilical vein endothelial cells are analyzed. 28 upregulated microRNAs with EVOO-derived TRLs, which can regulate 22 genes related to atherosclerosis, are found. 21 upregulated microRNAs with SO-derived TRLs, which can regulate 20 genes related to atherosclerosis, are found. These microRNAs are mainly involved in angiogenesis, with a predominance of an anti-angiogenic effect with EVOO-derived TRLs. Other microRNAs upregulated with SO-derived TRLs are involved in cardiovascular diseases. Pathways for the target genes obtained from the upregulated microRNA with EVOO-derived TRLs are involved in lipid metabolism and inflammatory and defense response, while those with SO-derived TRLs are involved in lipid metabolic process. CONCLUSION EVOO-derived TRLs seem to produce a more atheroprotective profile than SO-derived TRLs. This study provides alternative mechanisms on the protective role of EVOO against the atherogenic process through microRNA regulation in endothelial cells.
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Affiliation(s)
- Concepción Santiago-Fernandez
- Instituto de Investigación Biomédica de Málaga-IBIMA, 29010, Málaga, Spain.,Unidad de Gestión Clínica de Aparato Digestivo, Hospital Universitario Virgen de la Victoria, 29010, Málaga, Spain.,Facultad de Medicina, Universidad de Málaga, 29010, Málaga, Spain
| | - Flores Martin-Reyes
- Instituto de Investigación Biomédica de Málaga-IBIMA, 29010, Málaga, Spain.,Unidad de Gestión Clínica de Aparato Digestivo, Hospital Universitario Virgen de la Victoria, 29010, Málaga, Spain.,Facultad de Medicina, Universidad de Málaga, 29010, Málaga, Spain
| | - Rocío Bautista
- Plataforma Andaluza de Bioinformática-SCBI, Universidad de Málaga, 29590, Málaga, Spain
| | - Mónica Tome
- Unidad de Gestión Clínica de Endocrinología y Nutrición, Hospital Regional Universitario, 29010, Málaga, Spain
| | - Josefa Gómez-Maldonado
- Unidad de Genómica y Ultrasecuenciación-SCBI, Universidad de Málaga, 29590, Málaga, Spain
| | - Carolina Gutierrez-Repiso
- Instituto de Investigación Biomédica de Málaga-IBIMA, 29010, Málaga, Spain.,Unidad de Gestión Clínica de Endocrinología y Nutrición, Hospital Universitario Virgen de la Victoria, 29010, Málaga, Spain.,CIBER Fisiopatología de la Obesidad y Nutrición-CIBEROBN, Instituto de Salud Carlos III, 29010, Málaga, Spain
| | - Francisco J Tinahones
- Instituto de Investigación Biomédica de Málaga-IBIMA, 29010, Málaga, Spain.,Facultad de Medicina, Universidad de Málaga, 29010, Málaga, Spain.,Unidad de Gestión Clínica de Endocrinología y Nutrición, Hospital Universitario Virgen de la Victoria, 29010, Málaga, Spain.,CIBER Fisiopatología de la Obesidad y Nutrición-CIBEROBN, Instituto de Salud Carlos III, 29010, Málaga, Spain
| | - Eduardo Garcia-Fuentes
- Instituto de Investigación Biomédica de Málaga-IBIMA, 29010, Málaga, Spain.,Unidad de Gestión Clínica de Aparato Digestivo, Hospital Universitario Virgen de la Victoria, 29010, Málaga, Spain
| | - Lourdes Garrido-Sánchez
- Instituto de Investigación Biomédica de Málaga-IBIMA, 29010, Málaga, Spain.,Unidad de Gestión Clínica de Endocrinología y Nutrición, Hospital Universitario Virgen de la Victoria, 29010, Málaga, Spain.,CIBER Fisiopatología de la Obesidad y Nutrición-CIBEROBN, Instituto de Salud Carlos III, 29010, Málaga, Spain
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5
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Sur S, Nakanishi H, Flaveny C, Ippolito JE, McHowat J, Ford DA, Ray RB. Inhibition of the key metabolic pathways, glycolysis and lipogenesis, of oral cancer by bitter melon extract. Cell Commun Signal 2019; 17:131. [PMID: 31638999 PMCID: PMC6802351 DOI: 10.1186/s12964-019-0447-y] [Citation(s) in RCA: 39] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2019] [Accepted: 09/27/2019] [Indexed: 12/18/2022] Open
Abstract
BACKGROUND Metabolic reprogramming is one of the hallmarks of cancer which favours rapid energy production, biosynthetic capabilities and therapy resistance. In our previous study, we showed bitter melon extract (BME) prevents carcinogen induced mouse oral cancer. RNA sequence analysis from mouse tongue revealed a significant modulation in "Metabolic Process" by altering glycolysis and lipid metabolic pathways in BME fed group as compared to cancer group. In present study, we evaluated the effect of BME on glycolysis and lipid metabolism pathways in human oral cancer cells. METHODS Cal27 and JHU022 cells were treated with BME. RNA and protein expression were analysed for modulation of glycolytic and lipogenesis genes by quantitative real-time PCR, western blot analyses and immunofluorescence. Lactate and pyruvate level was determined by GC/MS. Extracellular acidification and glycolytic rate were measured using the Seahorse XF analyser. Shotgun lipidomics in Cal27 and JHU022 cell lines following BME treatment was performed by ESI/ MS. ROS was measured by FACS. RESULTS Treatment with BME on oral cancer cell lines significantly reduced mRNA and protein expression levels of key glycolytic genes SLC2A1 (GLUT-1), PFKP, LDHA, PKM and PDK3. Pyruvate and lactate levels and glycolysis rate were reduced in oral cancer cells following BME treatment. In lipogenesis pathway, we observed a significant reduction of genes involves in fatty acid biogenesis, ACLY, ACC1 and FASN, at the mRNA and protein levels following BME treatment. Further, BME treatment significantly reduced phosphatidylcholine, phosphatidylethanolamine, and plasmenylethanolamine, and reduced iPLA2 activity. Additionally, BME treatment inhibited lipid raft marker flotillin expression and altered its subcellular localization. ER-stress associated CHOP expression and generation of mitochondrial reactive oxygen species were induced by BME, which facilitated apoptosis. CONCLUSION Our study revealed that bitter melon extract inhibits glycolysis and lipid metabolism and induces ER and oxidative stress-mediated cell death in oral cancer. Thus, BME-mediated metabolic reprogramming of oral cancer cells will have important preventive and therapeutic implications along with conventional therapies.
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Affiliation(s)
- Subhayan Sur
- 0000 0004 1936 9342grid.262962.bDepartment of Pathology, Saint Louis University, 1100 South Grand Boulevard, St. Louis, MO 63104 USA
| | - Hiroshi Nakanishi
- 0000 0004 1936 9342grid.262962.bDepartment of Pathology, Saint Louis University, 1100 South Grand Boulevard, St. Louis, MO 63104 USA
| | - Colin Flaveny
- 0000 0004 1936 9342grid.262962.bDepartment of Pharmacology and Physiology, Saint Louis University School of Medicine, St. Louis, MO USA
| | - Joseph E. Ippolito
- 0000 0001 2355 7002grid.4367.6Mallinckrodt Institute of Radiology, Washington University in Saint Louis School of Medicine, Saint Louis, MO USA
| | - Jane McHowat
- 0000 0004 1936 9342grid.262962.bDepartment of Pathology, Saint Louis University, 1100 South Grand Boulevard, St. Louis, MO 63104 USA
| | - David A. Ford
- 0000 0004 1936 9342grid.262962.bBiochemistry and Molecular Biology, Saint Louis University, Saint Louis, MO USA
| | - Ratna B. Ray
- 0000 0004 1936 9342grid.262962.bDepartment of Pathology, Saint Louis University, 1100 South Grand Boulevard, St. Louis, MO 63104 USA
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6
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Marentette JO, Wang M, Michel CR, Powell R, Zhang X, Reisdorph N, Fritz KS, Ju C. Multi-omics Analysis of Liver Infiltrating Macrophages Following Ethanol Consumption. Sci Rep 2019; 9:7776. [PMID: 31123328 PMCID: PMC6533323 DOI: 10.1038/s41598-019-43240-4] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2018] [Accepted: 11/28/2018] [Indexed: 02/07/2023] Open
Abstract
Alcoholic liver disease (ALD) is a significant health hazard and economic burden affecting approximately 10 million people in the United States. ALD stems from the production of toxic-reactive metabolites, oxidative stress and fat accumulation in hepatocytes which ultimately results in hepatocyte death promoting hepatitis and fibrosis deposition. Monocyte-derived infiltrating Ly6Chi and Ly6Clow macrophages are instrumental in perpetuating and resolving the hepatitis and fibrosis associated with ALD pathogenesis. In the present study we isolated liver infiltrating macrophages from mice on an ethanol diet and subjected them to metabolomic and proteomic analysis to provide a broad assessment of the cellular metabolite and protein differences between infiltrating macrophage phenotypes. We identified numerous differentially regulated metabolites and proteins between Ly6Chi and Ly6Clow macrophages. Bioinformatic analysis for pathway enrichment of the differentially regulated metabolites showed a significant number of metabolites involved in the processes of glycerophospholipid metabolism, arachidonic acid metabolism and phospholipid biosynthesis. From analysis of the infiltrating macrophage proteome, we observed a significant enrichment in the biological processes of antigen presentation, actin polymerization and organization, phagocytosis and apoptotic regulation. The data presented herein could yield exciting new research avenues for the analysis of signaling pathways regulating macrophage polarization in ALD.
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Affiliation(s)
- John O Marentette
- Skaggs School of Pharmacy and Pharmaceutical Sciences, University of Colorado Anschutz Medical Campus, Aurora, CO, 80045, USA
| | - Meng Wang
- Skaggs School of Pharmacy and Pharmaceutical Sciences, University of Colorado Anschutz Medical Campus, Aurora, CO, 80045, USA
| | - Cole R Michel
- Skaggs School of Pharmacy and Pharmaceutical Sciences, University of Colorado Anschutz Medical Campus, Aurora, CO, 80045, USA
| | - Roger Powell
- Skaggs School of Pharmacy and Pharmaceutical Sciences, University of Colorado Anschutz Medical Campus, Aurora, CO, 80045, USA
| | - Xing Zhang
- Skaggs School of Pharmacy and Pharmaceutical Sciences, University of Colorado Anschutz Medical Campus, Aurora, CO, 80045, USA
| | - Nichole Reisdorph
- Skaggs School of Pharmacy and Pharmaceutical Sciences, University of Colorado Anschutz Medical Campus, Aurora, CO, 80045, USA
| | - Kristofer S Fritz
- Skaggs School of Pharmacy and Pharmaceutical Sciences, University of Colorado Anschutz Medical Campus, Aurora, CO, 80045, USA.
| | - Cynthia Ju
- Skaggs School of Pharmacy and Pharmaceutical Sciences, University of Colorado Anschutz Medical Campus, Aurora, CO, 80045, USA.
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7
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Kispert S, Marentette J, McHowat J. Cigarette smoking promotes bladder cancer via increased platelet-activating factor. Physiol Rep 2019; 7:e13981. [PMID: 30756528 PMCID: PMC6372534 DOI: 10.14814/phy2.13981] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2018] [Revised: 12/18/2018] [Accepted: 12/20/2018] [Indexed: 02/06/2023] Open
Abstract
Cigarette smoking is the number one risk factor for bladder cancer development and epidemiological data suggest that nearly half of all bladder cancer patients have a history of smoking. In addition to stimulating the growth of a primary tumor, it has been shown that there is a correlation between smoking and tumor metastasis. Platelet activating factor (PAF) is expressed on the cell surface of the activated endothelium and, through binding with the PAF-receptor (PAF-R), facilitates transendothelial migration of cells in the circulation (McHowat et al. Biochemistry 40:14921-14931; 2001). In this study, we show that the exposure of bladder cancer cells to cigarette smoke extract (CSE) results in increased PAF accumulation and increased expression of the PAF-R. Furthermore, treatment with CSE increases adherence of bladder cancer cells to bladder endothelial cells and could be abrogated by pretreatment with ginkgolide B. Immunohistochemical analysis of tumor biopsy samples from bladder cancer patients who smoked revealed increased PAF and the PAF-R in tumor regions when compared to normal tissue. These data highlight a pathway in bladder cancer that is influenced by CSE which could facilitate primary tumor growth and increase metastatic potential. Targeting of the PAF-PAFR interaction could serve as a beneficial therapeutic target for managing further growth of a developing tumor.
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Affiliation(s)
- Shannon Kispert
- Department of BiologyUniversity of North GeorgiaOakwoodGeorgia
| | - John Marentette
- Skaggs School of Pharmacy and Pharmaceutical SciencesUniversity of Colorado Anschutz Medical CampusAuroraColorado
| | - Jane McHowat
- Department of PathologySaint Louis University School of MedicineSt. LouisMissouri
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8
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Selectivity of phospholipid hydrolysis by phospholipase A 2 enzymes in activated cells leading to polyunsaturated fatty acid mobilization. Biochim Biophys Acta Mol Cell Biol Lipids 2018; 1864:772-783. [PMID: 30010011 DOI: 10.1016/j.bbalip.2018.07.002] [Citation(s) in RCA: 73] [Impact Index Per Article: 12.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2018] [Revised: 07/08/2018] [Accepted: 07/10/2018] [Indexed: 12/14/2022]
Abstract
Phospholipase A2s are enzymes that hydrolyze the fatty acid at the sn-2 position of the glycerol backbone of membrane glycerophospholipids. Given the asymmetric distribution of fatty acids within phospholipids, where saturated fatty acids tend to be present at the sn-1 position, and polyunsaturated fatty acids such as those of the omega-3 and omega-6 series overwhelmingly localize in the sn-2 position, the phospholipase A2 reaction is of utmost importance as a regulatory checkpoint for the mobilization of these fatty acids and the subsequent synthesis of proinflammatory omega-6-derived eicosanoids on one hand, and omega-3-derived specialized pro-resolving mediators on the other. The great variety of phospholipase A2s, their differential substrate selectivity under a variety of pathophysiological conditions, as well as the different compartmentalization of each enzyme and accessibility to substrate, render this class of enzymes also key to membrane phospholipid remodeling reactions, and the generation of specific lipid mediators not related with canonical metabolites of omega-6 or omega-3 fatty acids. This review highlights novel findings regarding the selective hydrolysis of phospholipids by phospholipase A2s and the influence this may have on the ability of these enzymes to generate distinct lipid mediators with essential functions in biological processes. This brings a new understanding of the cellular roles of these enzymes depending upon activation conditions.
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9
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Shu S, Xu Y, Xie L, Ouyang Y. The role of C/EBPβ phosphorylation in modulating membrane phospholipids repairing in LPS-induced human lung/bronchial epithelial cells. Gene 2017; 629:76-85. [PMID: 28760550 PMCID: PMC7125708 DOI: 10.1016/j.gene.2017.07.076] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2016] [Revised: 06/22/2017] [Accepted: 07/27/2017] [Indexed: 11/19/2022]
Abstract
Acute lung injury/acute respiratory distress syndrome (ALI/ARDS) is a common critical emergency with high mortality in clinical practice. The key mechanism of ALI/ARDS is that the excessive inflammatory response damages the integrity of alveolar and bronchial cell membrane and thus affects their basic function. Phospholipids are the main component of cell membranes. Phospholipase A2 (PLA2), which catalyzes the cleavage of membrane phospholipids, is the most important inflammatory mediator of ALI. However, clara cell secretory protein 1 (CCSP1), an endogenous PLA2 inhibitor can increase the self-defense of membrane phospholipids. Thus, CCSP1 up-regulation and PLA2 inhibition constitutes an effective method for ensuring the stability of membrane phospholipids and for the treatment of ALI/ARDS. In the present study, we developed an in vitro model of ALI via lipopolysaccharide (LPS) stimulation of a human bronchial epithelial cell line, BEAS-2B, and assessed the mRNA and protein levels of CCSP1 and PLA2 in the model cells. The results demonstrated LPS induction inhibited the transcription and protein expression of CCSP1, but only the protein level of membrane associated PLA2 was increased, suggesting that in the in vitro ALI model, abnormally regulated CCSP1 transcription plays a crucial role in the damage of cell membrane. To find out the reason that CCSP1 expression was decreased in the ALI model, we predicted, by means of bioinformatics, putative transcription factors which would bind to CCSP1 promoter, examined their background and expression, and found that a transcription factor, CCAAT/enhancer binding protein β (C/EBP β), was correlated with the transcription of CCSP1 in the in vitro ALI model, and its phosphorylation in the model was decreased. CHIP-PCR and luciferase reporter assay revealed that C/EBP β bound to CCSP1 promoter and facilitated its transcription. Therefore, we conclude that there is a C/EBP β/CCSP1/PLA2 pathway in the in vitro ALI model. The study of underlying mechanism show that the activity of C/EBP β depends on its phosphorylation:LPS stimulation reduced C/EBP β phosphorylation and suppressed the transcription of CCSP1 in BEAS-2B cells, which resulted in enhanced PLA2 and the consequent membrane damage. And further study shows that overexpression of CDK2(Cyclindependent kinase 2), promoted the phosphorylation of C/EBP β and inhibited PLA2 through the C/EBP β/CCSP1/PLA2 pathway, so as to attenuate membrane damage. The significance of this study lies in that artificial C/EBP β phosphorylation regulation may ease the membrane damage in ALI and improve membrane repair. CDK2 over-expression promotes C/EBPβ phosphorylation and improves membrane repair through C/EBPβ/CCSP/PLA2 pathway in ALI.
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Affiliation(s)
- Shiyu Shu
- Anesthesiology Department, Children's Hospital of FudanUniversity,Shanghai,201102, China.
| | - Yan Xu
- Children's Hospital of Chongqing Medical University, Ministry of Education Key Laboratory of Child Development and Disorders, Chongqing, 400014,China
| | - Ling Xie
- Children's Hospital of Chongqing Medical University, Ministry of Education Key Laboratory of Child Development and Disorders, Chongqing, 400014,China
| | - Yufang Ouyang
- Children's Hospital of Chongqing Medical University, Ministry of Education Key Laboratory of Child Development and Disorders, Chongqing, 400014,China
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10
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Buland JR, Wasserloos KJ, Tyurin VA, Tyurina YY, Amoscato AA, Mallampalli RK, Chen BB, Zhao J, Zhao Y, Ofori-Acquah S, Kagan VE, Pitt BR. Biosynthesis of oxidized lipid mediators via lipoprotein-associated phospholipase A2 hydrolysis of extracellular cardiolipin induces endothelial toxicity. Am J Physiol Lung Cell Mol Physiol 2016; 311:L303-16. [PMID: 27233995 PMCID: PMC5142456 DOI: 10.1152/ajplung.00038.2016] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2016] [Accepted: 05/24/2016] [Indexed: 01/16/2023] Open
Abstract
We (66) have previously described an NSAID-insensitive intramitochondrial biosynthetic pathway involving oxidation of the polyunsaturated mitochondrial phospholipid, cardiolipin (CL), followed by hydrolysis [by calcium-independent mitochondrial calcium-independent phospholipase A2-γ (iPLA2γ)] of oxidized CL (CLox), leading to the formation of lysoCL and oxygenated octadecadienoic metabolites. We now describe a model system utilizing oxidative lipidomics/mass spectrometry and bioassays on cultured bovine pulmonary artery endothelial cells (BPAECs) to assess the impact of CLox that we show, in vivo, can be released to the extracellular space and may be hydrolyzed by lipoprotein-associated PLA2 (Lp-PLA2). Chemically oxidized liposomes containing bovine heart CL produced multiple oxygenated species. Addition of Lp-PLA2 hydrolyzed CLox and produced (oxygenated) monolysoCL and dilysoCL and oxidized octadecadienoic metabolites including 9- and 13-hydroxyoctadecadienoic (HODE) acids. CLox caused BPAEC necrosis that was exacerbated by Lp-PLA2 Lower doses of nonlethal CLox increased permeability of BPAEC monolayers. This effect was exacerbated by Lp-PLA2 and partially mimicked by authentic monolysoCL or 9- or 13-HODE. Control mice plasma contained virtually no detectable CLox; in contrast, 4 h after Pseudomonas aeruginosa (P. aeruginosa) infection, 34 ± 8 mol% (n = 6; P < 0.02) of circulating CL was oxidized. In addition, molar percentage of monolysoCL increased twofold after P. aeruginosa in a subgroup analyzed for these changes. Collectively, these studies suggest an important role for 1) oxidation of CL in proinflammatory environments and 2) possible hydrolysis of CLox in extracellular spaces producing lysoCL and oxidized octadecadienoic acid metabolites that may lead to impairment of pulmonary endothelial barrier function and necrosis.
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Affiliation(s)
- Justin R Buland
- Children's Hospital of Pittsburgh, Pittsburgh, Pennsylvania; University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania; Vascular Medicine Institute, Pittsburgh, Pennsylvania
| | - Karla J Wasserloos
- University of Pittsburgh Graduate School of Public Health, Pittsburgh, Pennsylvania
| | - Vladimir A Tyurin
- University of Pittsburgh Graduate School of Public Health, Pittsburgh, Pennsylvania
| | - Yulia Y Tyurina
- University of Pittsburgh Graduate School of Public Health, Pittsburgh, Pennsylvania
| | - Andrew A Amoscato
- University of Pittsburgh Graduate School of Public Health, Pittsburgh, Pennsylvania
| | - Rama K Mallampalli
- Division of Pulmonary, Allergy and Critical Care Medicine, Department of Medicine, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania; Acute Lung Injury Center of Excellence, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania; VA Pittsburgh Health Care System, Pittsburgh, Pennsylvania; Department of Cell Biology and Physiology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania
| | - Bill B Chen
- Division of Pulmonary, Allergy and Critical Care Medicine, Department of Medicine, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania; Acute Lung Injury Center of Excellence, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania
| | - Jing Zhao
- Vascular Medicine Institute, Pittsburgh, Pennsylvania; Division of Pulmonary, Allergy and Critical Care Medicine, Department of Medicine, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania; Acute Lung Injury Center of Excellence, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania
| | - Yutong Zhao
- University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania; Vascular Medicine Institute, Pittsburgh, Pennsylvania; Division of Pulmonary, Allergy and Critical Care Medicine, Department of Medicine, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania; Acute Lung Injury Center of Excellence, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania
| | - Solomon Ofori-Acquah
- University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania; Vascular Medicine Institute, Pittsburgh, Pennsylvania
| | - Valerian E Kagan
- University of Pittsburgh Graduate School of Public Health, Pittsburgh, Pennsylvania
| | - Bruce R Pitt
- University of Pittsburgh Graduate School of Public Health, Pittsburgh, Pennsylvania;
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Villar J, Cabrera-Benítez NE, Valladares F, García-Hernández S, Ramos-Nuez Á, Martín-Barrasa JL, Muros M, Kacmarek RM, Slutsky AS. Tryptase is involved in the development of early ventilator-induced pulmonary fibrosis in sepsis-induced lung injury. CRITICAL CARE : THE OFFICIAL JOURNAL OF THE CRITICAL CARE FORUM 2015; 19:138. [PMID: 25871971 PMCID: PMC4391146 DOI: 10.1186/s13054-015-0878-9] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/02/2014] [Accepted: 03/12/2015] [Indexed: 12/30/2022]
Abstract
Introduction Most patients with sepsis and acute lung injury require mechanical ventilation to improve oxygenation and facilitate organ repair. Mast cells are important in response to infection and resolution of tissue injury. Since tryptase secreted from mast cells has been associated with tissue fibrosis, we hypothesized that tryptase would be involved in the early development of ventilator-induced pulmonary fibrosis in a clinically relevant model of sepsis-induced lung injury. Methods Prospective, randomized, controlled animal study using Sprague-Dawley rats. Sepsis was induced by cecal ligation and perforation. Animals were randomized to spontaneous breathing or two ventilatory strategies for 4 h: protective ventilation with tidal volume (VT) = 6 ml/kg plus 10 cmH2O positive end-expiratory pressure (PEEP) or injurious ventilation with VT = 20 ml/kg plus 2 cmH2O PEEP. Healthy, non-ventilated animals served as non-septic controls. We studied the following end points: histology, serum cytokine levels, hydroxyproline content, tryptase and proteinase-activated receptor-2 (PAR-2) protein level in lung homogenates, and tryptase and PAR-2 immunohistochemical localization in the lungs. Results All septic animals developed acute lung injury. Animals ventilated with high VT had a significant increase of pulmonary fibrosis, hydroxyproline content, tryptase and PAR-2 protein levels compared to septic controls (P <0.0001). However, protective ventilation attenuated sepsis-induced lung injury and decreased lung tryptase and PAR-2 protein levels. Immunohistochemical staining confirmed the presence of tryptase and PAR-2 in the lungs. Conclusions Mechanical ventilation modified tryptase and PAR-2 in injured lungs. Increased levels of these proteins were associated with development of sepsis and ventilator-induced pulmonary fibrosis early in the course of sepsis-induced lung injury.
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Kispert S, Marentette J, McHowat J. Cigarette smoke induces cell motility via platelet-activating factor accumulation in breast cancer cells: a potential mechanism for metastatic disease. Physiol Rep 2015; 3:3/3/e12318. [PMID: 25802360 PMCID: PMC4393154 DOI: 10.14814/phy2.12318] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Most cancer deaths are a result of metastasis rather than the primary tumor. Although cigarette smoking has been determined as a risk factor for several cancers, its role in metastasis has not been studied in detail. We propose that cigarette smoking contributes to metastatic disease via inhibition of breast cancer cell platelet-activating factor acetylhydrolase (PAF-AH), resulting in PAF accumulation and a subsequent increase in cell motility. We studied several breast cell lines, including immortalized mammary epithelial cells (MCF-10A), luminal A hormone positive MCF-7, basal-like triple negative MDA-MB-468, and claudin-low triple-negative highly metastatic MDA-MB-231 breast tumor cells. We exposed cells to cigarette smoke extract (CSE) for up to 48 h. CSE inhibited PAF-AH activity, increased PAF accumulation, and increased cell motility in MDA-MB-231 metastatic triple negative breast cancer cells. The calcium-independent phospholipase A2 (iPLA2) inhibitor, (S) bromoenol lactone ((S)-BEL) was used to prevent the accumulation of PAF and further prevented the increase in cell motility seen previously when cells were exposed to CSE. Thus, iPLA2 or PAF may represent a therapeutic target to manage metastatic disease, particularly in triple-negative breast cancer patients who smoke.
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Affiliation(s)
- Shannon Kispert
- Department of Pathology, Saint Louis University School of Medicine, St. Louis, Missouri
| | - John Marentette
- Department of Pathology, Saint Louis University School of Medicine, St. Louis, Missouri
| | - Jane McHowat
- Department of Pathology, Saint Louis University School of Medicine, St. Louis, Missouri
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Ayilavarapu S, Kantarci A, Hasturk H, Van Dyke TE. IPLA2 mRNA expression by human neutrophils in type 2 diabetes and chronic periodontitis. JOURNAL OF THE INTERNATIONAL ACADEMY OF PERIODONTOLOGY 2014; 16:121-126. [PMID: 25654966 PMCID: PMC4793369] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Type 2 diabetes mellitus (T2D) is becoming increasingly prevalent worldwide and complications of T2D cause significant systemic and dental morbidity in the susceptible individual. Although T2D has been linked as a significant risk factor for chronic periodontitis (CP), molecular mechanisms explaining the pathogenesis and inflammatory impact of CP in T2D are lacking. iPLA2 is the calcium-independent form of phospholipase A2. In previous studies, we demonstrated that iPLA2 enzyme activity is altered in T2D. The purpose of this study was to elucidate the level of the iPLA2 abnormality in T2D by measuring messenger RNA levels in T2D-associated CP. A total of 53 healthy and T2D subjects with CP were recruited for this study. The clinical periodontal exam included probing pocket depth, clinical attachment levels and bleeding on probing. Peripheral venous blood was collected and neutrophils were isolated. Real time polymerase chain reaction was used to quantify iPLA2 mRNA in neutrophils from healthy controls and people with diabetes. Results revealed that the prevalence of moderate to severe CP was increased in people with T2D. The iPLA, mRNA levels in diabetics with different severity of CP were not significantly different compared to healthy controls; 1.07 vs 0.97 (mild CP), 1.07 vs 0.85 (moderate CP) and 1.07 vs 1.05 (severe CP). Collectively, the data suggest that levels of iPLA2 mRNA in T2D are not different than in health and are not directly influenced by periodontal disease status. The impact of inflammation on iPLA2 regulation is at the level of activation of the enzyme rather than expression at the mRNA level.
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Affiliation(s)
- Srinivas Ayilavarapu
- Department of General Dentistry, Boston University Henry M. Goldman School of Dental Medicine, Boston, MA 02118
| | - Alpdogan Kantarci
- Department of Applied Oral Sciences, Forsyth Institute, Cambridge, MA 02142
| | - Hatice Hasturk
- Department of Applied Oral Sciences, Forsyth Institute, Cambridge, MA 02142
| | - Thomas E. Van Dyke
- Department of Applied Oral Sciences, Forsyth Institute, Cambridge, MA 02142
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14
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Kispert SE, Marentette JO, McHowat J. Enhanced breast cancer cell adherence to the lung endothelium via PAF acetylhydrolase inhibition: a potential mechanism for enhanced metastasis in smokers. Am J Physiol Cell Physiol 2014; 307:C951-6. [PMID: 25186013 DOI: 10.1152/ajpcell.00218.2014] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Cancer deaths are primarily caused by distant metastases, rather than by primary tumor growth; however, the role of smoking in metastasis remains unclear. We demonstrated previously that endothelial cell platelet-activating factor (PAF) production results in enhanced inflammatory cell recruitment to the lung. We propose that endothelial cell PAF accumulation plays a role in cancer cell migration to distal locations. We used cigarette smoke extract (CSE) to inhibit the activity of endothelial cell PAF acetylhydrolase (PAF-AH), which hydrolyzes and inactivates PAF, and determined whether this results in increased endothelial cell PAF accumulation and breast cancer adherence. Incubation of human lung microvascular endothelial cells (HMVEC-L) with CSE resulted in a significant inhibition of PAF-AH activity that was accompanied by increased PAF production and adherence of highly invasive MDA-MB-231 breast cancer cells. Pretreatment of HMVEC-L with (S)-bromoenol lactone to inhibit calcium-independent phospholipase A2β (iPLA2β, which initiates endothelial cell PAF production) prior to CSE exposure resulted in complete inhibition of MDA-MB-231 cell adherence. Similarly, pretreatment of MDA-MB-231 cells with the PAF receptor antagonist Ginkgo biloba resulted in inhibition of adherence to the endothelium. Immunoblot analysis indicated an increase in MDA-MB-231 cell PAF receptor expression with CSE exposure. Taken together, our data indicate that CSE exposure increases endothelial cell PAF production, resulting in enhanced adherence of tumor cells to the endothelium. Our in vitro data indicate that increased tumor cell adherence would lead to enhanced metastasis formation in smokers. Potential therapeutic targets include endothelial cell iPLA2β or the tumor cell PAF receptor.
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Affiliation(s)
- Shannon E Kispert
- Department of Pathology, Saint Louis University School of Medicine, St. Louis, Missouri
| | - John O Marentette
- Department of Pathology, Saint Louis University School of Medicine, St. Louis, Missouri
| | - Jane McHowat
- Department of Pathology, Saint Louis University School of Medicine, St. Louis, Missouri
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Zhang K, Wang P, Huang S, Wang X, Li T, Jin Y, Hehir M, Xu C. Different mechanism of LPS-induced calcium increase in human lung epithelial cell and microvascular endothelial cell: a cell culture study in a model for ARDS. Mol Biol Rep 2014; 41:4253-9. [PMID: 24584519 DOI: 10.1007/s11033-014-3296-1] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2013] [Accepted: 02/13/2014] [Indexed: 01/11/2023]
Abstract
Acute respiratory distress syndrome (ARDS) is a contemporary term incorporating the historic 'acute lung injury' and the colloquial term 'shock lung'. ARDS remains a serious and enigmatic human disease, causing significant mortality. The mechanisms involved at the alveolar cell/capillary endothelial interface have been explored but to date we lack clarity on the role of intracellular calcium ([Ca(2+)]i) fluxes across this interface. To explore the mechanisms of Ca(2+) induced inflammatory reaction in epithelial cells and pulmonary microvascular endothelial cells (HMVEC) located at the two sides of blood-air barrier, lung epithelial A549 and HMVEC cells were treated with LPS. Our results demonstrated that LPS evoked the increase of [Ca(2+)]i, TNF-α and IL-8 in both cells types. The [Ca(2+)]i increases involved intracellular but not extracellular Ca(2+) sources in A549, but both intracellular and extracellular Ca(2+) sources in HMVEC cells. The effects of LPS on both cells types were completely inhibited by the combination of LPS and CaSR-targeted siRNA. Furthermore, LPS-inhibited cell proliferations were significantly reversed by the combined treatment. Therefore, LPS induced different mechanisms of [Ca(2+)]i increase during the activation of CaSR in A549 and HMVEC cells, which translates into functional outputs related to ARDS.
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Affiliation(s)
- Kejing Zhang
- Ningbo Medical Center, LiHuiLi Hospital, Medical School, Ningbo University, Ningbo, 315041, China
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Group VIB Ca(2+)-independent phospholipase A(2γ) is associated with acute lung injury following trauma and hemorrhagic shock. J Trauma Acute Care Surg 2014; 75:767-74. [PMID: 24158193 DOI: 10.1097/ta.0b013e3182a924f2] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
BACKGROUND Gut-derived mediators are carried via mesenteric lymph duct into systemic circulation after trauma/hemorrhagic shock (T/HS), thus leading to acute lung injury (ALI)/multiple-organ dysfunction syndrome. Phospholipase A2 (PLA(2)) is a key enzyme for the production of lipid mediators in posthemorrhagic shock mesenteric lymph (PHSML). However, the precise functions of PLA(2) subtype, such as cytosolic PLA(2), secretory PLA(2), and Ca-independent PLA(2), in the acute phase of inflammation have remained unclear. Our previous study has suggested that the activation of Group VIB Ca-independent PLA(2γ) (PLA(2γ)) may be associated with increased lyso-phosphatidylcholines (LPCs) in the PHSML. Therefore, our purpose was to verify the role of iPLA(2γ) on the production of 2-polyunsaturated LPC species and the pathogenesis of T/HS-induced ALI using an iPLA(2γ)-specific inhibitor, R-(E)-6-(bromoethylene)-3-(1-naphthalenyl)-2H-tetrahydropyran-2-one (R-BEL). METHODS Male Sprague-Dawley rats were anesthetized and cannulated in blood vessels and mesenteric lymph duct. Animals in the T/HS group underwent a midline laparotomy plus hemorrhagic shock (mean arterial pressure, 35 mm Hg, 30 minutes) and 2-hour resuscitation with shed blood and 2× normal saline. Trauma/sham shock rats were performed the identical procedure without hemorrhage. R-BEL or DMSO was administered 30 minutes before T/HS or trauma/sham shock. Polyunsaturated LPCs and arachidonic acid in the PHSML were analyzed with a liquid chromatography/electrospray ionization-mass spectrometry. Furthermore, ALI was assessed by lung vascular permeability, myeloperoxidase activity, and histology. RESULTS T/HS increased 2-polyunsaturated LPCs and arachidonic acid in the PHSML. The R-BEL pretreatment significantly decreased these lipids and also inhibited ALI. CONCLUSION The iPLA(2γ) enzyme is possibly involved in the pathogenesis of ALI following T/HS through the mesenteric lymph pathway.
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Abstract
BACKGROUND After trauma and hemorrhagic shock (T/HS), a variety of inflammatory mediators enter the systemic circulation through mesenteric lymph ducts, leading to acute lung injury and multiple-organ dysfunction syndrome. Recent studies have demonstrated that post-HS mesenteric lymph (PHSML) activates polymorphonuclear leukocytes (PMNs) and causes vascular endothelial cell and red blood cell dysfunction. Furthermore, PHSML contains proinflammatory mediators, such as biologically active lipids. The purpose of this study was to identify the lipid mediators in PHSML and plasma by liquid chromatography/electrospray ionization mass spectrometry and then estimate the biologic activities of the identified lipids on PMNs. METHODS PHSML was collected from male Sprague-Dawley rats undergoing trauma (laparotomy) plus HS (40 mm Hg, 30 minutes) or sham shock (SS). The lipids in PHSML and plasma were extracted using the methods of Bligh and Dyer, and liquid chromatography/electrospray ionization mass spectrometry was performed. The biologic activities (superoxide production and elastase release) of identified lipids on human PMNs were tested. RESULTS Phosphatidylcholine, lysophosphatidylcholine (LPC), phosphatidylethanolamine, lysophosphatidylethanolamine (LPE), and sphingomyelin were detected in the PHSML. Furthermore, linoleoyl, arachidonoyl, and docosahexaenoyl LPCs and LPEs significantly increased in the PHSML of the T/HS group as compared with those of the T/SS group. In the plasma, arachidonoyl and docosahexaenoyl LPCs of the T/HS group also significantly increased in comparison with that of the T/SS group. Linoleoyl and arachidonoyl LPCs and LPEs showed the priming activity on N-formyl-methionyl-leucyl-phenylalanine-activated PMNs. The elastase release was also induced by linoleoyl and arachidonoyl LPCs. CONCLUSION Mesenteric lymph after T/HS contains biologically active lipids, such as LPCs and LPEs with polyunsaturated fatty acids, which may be involved in the pathogenesis of acute lung injury/multiple-organ dysfunction syndrome.
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Sharma J, Young DM, Marentette JO, Rastogi P, Turk J, McHowat J. Lung endothelial cell platelet-activating factor production and inflammatory cell adherence are increased in response to cigarette smoke component exposure. Am J Physiol Lung Cell Mol Physiol 2012; 302:L47-55. [PMID: 21984569 PMCID: PMC3349370 DOI: 10.1152/ajplung.00179.2011] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2011] [Accepted: 10/03/2011] [Indexed: 12/30/2022] Open
Abstract
An early event in the pathogenesis of emphysema is the development of inflammation associated with accumulation of polymorphonuclear leukocytes (PMN) in small airways, and inflammatory cell recruitment from the circulation involves migration across endothelial and epithelial cell barriers. Platelet-activating factor (PAF) promotes transendothelial migration in several vascular beds, and we postulated that increased PAF production in the airways of smokers might enhance inflammatory cell recruitment and exacerbate inflammation. To examine this possibility, we incubated human lung microvascular endothelial cells (HMVEC-L) with cigarette smoke extract (CSE) and found that CSE inhibits PAF-acetylhydrolase (PAF-AH) activity. This enhances HMVEC-L PAF production and PMN adherence, and adherence is blocked by PAF receptor antagonists (CV3988 or ginkgolide B). CSE also inhibited PAF-AH activity of lung endothelial cells isolated from wild-type (WT) and iPLA(2)β knockout mice, and with WT cells, CSE enhanced PAF production and RAW 264.7 cell adherence. In contrast, CSE did not affect PAF production or RAW 264.7 cell adherence to iPLA(2)β-null cells, suggesting that iPLA(2)β plays an important role in PAF production by lung endothelial cells. These findings suggest that inhibition of PAF-AH by components of cigarette smoke may initiate or exacerbate inflammatory lung disease by enhancing PAF production and promoting accumulation of inflammatory cells in small airways. In addition, iPLA(2)β is identified as a potential target for therapeutic interventions to reduce airway inflammation and the progression of chronic lung disease.
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Affiliation(s)
- Janhavi Sharma
- Department of Pathology, Saint Louis University School of Medicine, St. Louis, Missouri 63104, USA
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PGE2 Release from Tryptase-Stimulated Rabbit Ventricular Myocytes is Mediated by Calcium-Independent Phospholipase A2γ. Lipids 2011; 46:391-7. [DOI: 10.1007/s11745-011-3554-0] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2011] [Accepted: 03/16/2011] [Indexed: 12/15/2022]
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McHowat J, Gullickson G, Hoover RG, Sharma J, Turk J, Kornbluth J. Platelet-activating factor and metastasis: calcium-independent phospholipase A2β deficiency protects against breast cancer metastasis to the lung. Am J Physiol Cell Physiol 2011; 300:C825-32. [PMID: 21228317 DOI: 10.1152/ajpcell.00502.2010] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
We determined the contribution of calcium-independent phospholipase A(2)β (iPLA(2)β) to lung metastasis development following breast cancer injection into wild-type (WT) and iPLA(2)β-knockout (iPLA(2)β-KO) mice. WT and iPLA(2)β-KO mice were injected in the mammary pad with 200,000 E0771 breast cancer cells. There was no difference in primary tumor size between WT and iPLA(2)β-KO mice at 27 days postinjection. However, we observed an 11-fold greater number of breast cancer cells in the lungs of WT mice compared with iPLA(2)β-KO animals (P < 0.05). Isolated WT lung endothelial cells demonstrated a significant increase in platelet-activating factor (PAF) production when stimulated with thrombin [1 IU/ml, 10 min, 4,330 ± 555 vs. 15,227 ± 1,043 disintegrations per minute (dpm), P < 0.01] or TNF-α (10 ng/ml, 2 h, 16,532 ± 538 dpm, P < 0.01). Adherence of E0771 cells to WT endothelial cells was increased by thrombin (4.8 ± 0.3% vs. 70.9 ± 6.3, P < 0.01) or TNF-α (60.5 ± 4.3, P < 0.01). These responses were blocked by pretreatment with the iPLA(2)β-selective inhibitor (S)-bromoenol lactone and absent in lung endothelial cells from iPLA(2)β-KO mice. These data indicate that endothelial cell iPLA(2)β is responsible for PAF production and adherence of E0771 cells and may play a role in cancer cell migration to distal locations.
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Affiliation(s)
- Jane McHowat
- Department of Pathology, Saint Louis University School of Medicine, Missouri 63104, USA.
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21
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Alberghina M. Phospholipase A2: New lessons from endothelial cells. Microvasc Res 2010; 80:280-5. [DOI: 10.1016/j.mvr.2010.03.013] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2010] [Revised: 03/24/2010] [Accepted: 03/24/2010] [Indexed: 01/05/2023]
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Sharma J, Turk J, McHowat J. Endothelial cell prostaglandin I(2) and platelet-activating factor production are markedly attenuated in the calcium-independent phospholipase A(2)beta knockout mouse. Biochemistry 2010; 49:5473-81. [PMID: 20521843 DOI: 10.1021/bi100752u] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
Damage and activation of lung endothelium can lead to interstitial edema, infiltration of inflammatory cells into the interstitium and airways, and production of inflammatory metabolites, all of which propagate airway inflammation in a variety of diseases. We have previously determined that stimulation of human microvascular endothelial cells from lung (HMVEC-L) results in activation of a calcium-independent phospholipase A(2) (iPLA(2)), and this leads to arachidonic acid release and production of prostaglandin I(2) (PGI(2)) and platelet-activating factor (PAF). We stimulated lung endothelial cells isolated from iPLA(2)beta-knockout (KO) and wild type (WT) mice with thrombin and tryptase to determine the role of iPLA(2)beta in endothelial cell membrane phospholipid hydrolysis. Thrombin or tryptase stimulation of WT lung endothelial cells resulted in increased arachidonic acid release and production of PGI(2) and PAF. Arachidonic acid release and PGI(2) production by stimulated iPLA(2)beta-KO endothelial cells were significantly reduced compared to WT. Measured PLA(2) activity and PGI(2) production by iPLA(2)beta-KO cells were suppressed by pretreatment with (R)-bromoenol lactone (R-BEL), which is a selective inhibitor of iPLA2gamma. In contrast to the increase in PAF production induced by stimulation of WT endothelial cells, none was observed for KO cells, and this suggests that endothelial PAF production is entirely dependent on iPLA(2)beta activity. Because inflammatory cell recruitment involves the interaction of endothelial cell PAF with PAF receptors on circulating cells, these data suggest that iPLA(2)beta may be a suitable therapeutic target for the treatment of inflammatory lung diseases.
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Affiliation(s)
- Janhavi Sharma
- Department of Pathology, Saint Louis University School of Medicine, St. Louis, Missouri 63104, USA
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Sun GY, Shelat PB, Jensen MB, He Y, Sun AY, Simonyi A. Phospholipases A2 and inflammatory responses in the central nervous system. Neuromolecular Med 2009; 12:133-48. [PMID: 19855947 DOI: 10.1007/s12017-009-8092-z] [Citation(s) in RCA: 131] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2009] [Accepted: 09/25/2009] [Indexed: 12/21/2022]
Abstract
Phospholipases A2 (PLA2s) belong to a superfamily of enzymes responsible for hydrolyzing the sn-2 fatty acids of membrane phospholipids. These enzymes are known to play multiple roles for maintenance of membrane phospholipid homeostasis and for production of a variety of lipid mediators. Over 20 different types of PLA2s are present in the mammalian cells, and in snake and bee venom. Despite their common function in hydrolyzing fatty acids of phospholipids, they are diversely encoded by a number of genes and express proteins that are regulated by different mechanisms. Recent studies have focused on the group IV calcium-dependent cytosolic cPLA2, the group VI calcium-independent iPLA2, and the group II small molecule secretory sPLA2. In the central nervous system (CNS), these PLA2s are distributed among neurons and glial cells. Although the physiological role of these PLA2s in regulating neural cell function has not yet been clearly elucidated, there is increasing evidence for their involvement in receptor signaling and transcriptional pathways that link oxidative events to inflammatory responses that underline many neurodegenerative diseases. Recent studies also reveal an important role of cPLA2 in modulating neuronal excitatory functions, sPLA2 in the inflammatory responses, and iPLA2 with childhood neurologic disorders associated with brain iron accumulation. The goal for this review is to better understand the structure and function of these PLA2s and to highlight specific types of PLA2s and their cross-talk mechanisms in these inflammatory responses under physiological and pathological conditions in the CNS.
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Affiliation(s)
- Grace Y Sun
- Department of Biochemistry, University of Missouri, 117 Schweitzer Hall, Columbia, MO 65211, USA.
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