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Ali O, Szabó A. Review of Eukaryote Cellular Membrane Lipid Composition, with Special Attention to the Fatty Acids. Int J Mol Sci 2023; 24:15693. [PMID: 37958678 PMCID: PMC10649022 DOI: 10.3390/ijms242115693] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2023] [Revised: 10/24/2023] [Accepted: 10/25/2023] [Indexed: 11/15/2023] Open
Abstract
Biological membranes, primarily composed of lipids, envelop each living cell. The intricate composition and organization of membrane lipids, including the variety of fatty acids they encompass, serve a dynamic role in sustaining cellular structural integrity and functionality. Typically, modifications in lipid composition coincide with consequential alterations in universally significant signaling pathways. Exploring the various fatty acids, which serve as the foundational building blocks of membrane lipids, provides crucial insights into the underlying mechanisms governing a myriad of cellular processes, such as membrane fluidity, protein trafficking, signal transduction, intercellular communication, and the etiology of certain metabolic disorders. Furthermore, comprehending how alterations in the lipid composition, especially concerning the fatty acid profile, either contribute to or prevent the onset of pathological conditions stands as a compelling area of research. Hence, this review aims to meticulously introduce the intricacies of membrane lipids and their constituent fatty acids in a healthy organism, thereby illuminating their remarkable diversity and profound influence on cellular function. Furthermore, this review aspires to highlight some potential therapeutic targets for various pathological conditions that may be ameliorated through dietary fatty acid supplements. The initial section of this review expounds on the eukaryotic biomembranes and their complex lipids. Subsequent sections provide insights into the synthesis, membrane incorporation, and distribution of fatty acids across various fractions of membrane lipids. The last section highlights the functional significance of membrane-associated fatty acids and their innate capacity to shape the various cellular physiological responses.
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Affiliation(s)
- Omeralfaroug Ali
- Agrobiotechnology and Precision Breeding for Food Security National Laboratory, Institute of Physiology and Animal Nutrition, Department of Animal Physiology and Health, Hungarian University of Agriculture and Life Sciences, Guba Sándor Str. 40, 7400 Kaposvár, Hungary;
| | - András Szabó
- Agrobiotechnology and Precision Breeding for Food Security National Laboratory, Institute of Physiology and Animal Nutrition, Department of Animal Physiology and Health, Hungarian University of Agriculture and Life Sciences, Guba Sándor Str. 40, 7400 Kaposvár, Hungary;
- HUN-REN-MATE Mycotoxins in the Food Chain Research Group, Hungarian University of Agriculture and Life Sciences, Guba Sándor Str. 40, 7400 Kaposvár, Hungary
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Identification of a Novel Angiogenesis Signalling circSCRG1/miR-1268b/NR4A1 Pathway in Atherosclerosis and the Regulatory Effects of TMP-PF In Vitro. Molecules 2023; 28:molecules28031271. [PMID: 36770940 PMCID: PMC9919304 DOI: 10.3390/molecules28031271] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2022] [Revised: 01/14/2023] [Accepted: 01/25/2023] [Indexed: 01/31/2023] Open
Abstract
Angiogenesis contributes to plaque instability in atherosclerosis and further increases cardio-cerebrovascular risk. Circular RNAs (circRNAs) are promising biomarkers and potential therapeutic targets for atherosclerosis. Previous studies have demonstrated that tetramethylpyrazine (TMP) and paeoniflorin (PF) combination treatment (TMP-PF) inhibited oxidized low-density lipoprotein (ox-LDL)-induced angiogenesis in vitro. However, whether circRNAs regulate angiogenesis in atherosclerosis and whether TMP-PF can regulate angiogenesis-related target circRNAs in atherosclerosis are unknown. In this study, human RNA sequencing (RNA-seq) data were analysed to identify differentially expressed (DE) circRNAs in atherosclerosis and to obtain angiogenesis-associated circRNA-microRNA (miRNA)-messenger RNA (mRNA) networks. Target circRNA-related mechanisms in angiogenesis in atherosclerosis and the regulatory effects of TMP-PF on target circRNA signalling were studied in ox-LDL-induced human umbilical vein endothelial cells (HUVECs) by cell proliferation, migration, tube formation, and luciferase reporter assays, real-time quantitative polymerase chain reaction (RT-qPCR) and Western blotting. A novel circRNA (circular stimulator of chondrogenesis 1, circSCRG1) was initially identified associated with angiogenesis in atherosclerosis, and circSCRG1 silencing up-regulated miR-1268b expression, increased nuclear receptor subfamily 4 group A member 1 (NR4A1) expression and then promoted ox-LDL-induced angiogenesis. TMP-PF (1 μmol/L TMP combined with 10 μmol/L PF) up-regulated circSCRG1 expression, mediated miR-1268b to suppress NR4A1 expression and then inhibited ox-LDL-induced angiogenesis. However, circSCRG1 silencing abolished the inhibitory effects of TMP-PF on ox-LDL-induced angiogenesis, which were rescued by the miR-1268b inhibitor. In conclusion, circSCRG1 might serve as a new target regulating angiogenesis in atherosclerosis via the circSCRG1/miR-1268b/NR4A1 axis and TMP-PF could regulate the circSCRG1/miR-1268b/NR4A1 axis to inhibit angiogenesis in atherosclerosis in vitro, indicating a novel angiogenesis signalling circSCRG1/miR-1268b/NR4A1 pathway in atherosclerosis and the regulatory effects of TMP-PF, which might provide a new pharmaceutical strategy to combat atherosclerotic plaque instability.
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Application of molecular docking approach in a novel eco-friendly impurity profiling HPLC-UV method for the simultaneous estimation of ternary hypoglycemic pharmaceutical mixture. Microchem J 2022. [DOI: 10.1016/j.microc.2022.107856] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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Ripon MAR, Bhowmik DR, Amin MT, Hossain MS. Role of arachidonic cascade in COVID-19 infection: A review. Prostaglandins Other Lipid Mediat 2021; 154:106539. [PMID: 33592322 PMCID: PMC7882227 DOI: 10.1016/j.prostaglandins.2021.106539] [Citation(s) in RCA: 27] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2020] [Revised: 02/01/2021] [Accepted: 02/08/2021] [Indexed: 02/06/2023]
Abstract
The World Health Organization has described the 2019 Coronavirus disease caused by an influenza-like virus called SARS-CoV-2 as a pandemic. Millions of people worldwide are already infected by this virus, and severe infection causes hyper inflammation, thus disrupting lung function, exacerbating breath difficulties, and death. Various inflammatory mediators bio-synthesized through the arachidonic acid pathway play roles in developing cytokine storms, injuring virus-infected cells. Since pro-inflammatory eicosanoids, including prostaglandins, and leukotrienes, are key brokers for physiological processes such as inflammation, fever, allergy, and pain but, their function in COVID-19 is not well defined. This study addresses eicosanoid's crucial role through the arachidonic pathway in inflammatory cascading and recommends using bioactive lipids, NSAIDs, steroids, cell phospholipase A2 (cPLA2) inhibitors, and specialized pro-resolving mediators (SPMs) to treat COVID-19 disease. The role of soluble epoxide hydrolase inhibitors (SEHIs) in promoting the activity of epoxyeicosatrienoic acids (EETs) and 17-hydroxide-docosahexaenoic acid (17-HDHA) is also discussed. Additional research that assesses the eicosanoid profile in COVID-19 patients or preclinical models generates novel insights into coronavirus-host interaction and inflammation regulation.
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Affiliation(s)
- Md Abdur Rahman Ripon
- Department of Pharmacy, Noakhali Science and Technology University, Noakhali 3814, Bangladesh
| | - Dipty Rani Bhowmik
- Department of Pharmacy, Noakhali Science and Technology University, Noakhali 3814, Bangladesh
| | - Mohammad Tohidul Amin
- Department of Pharmacy, Noakhali Science and Technology University, Noakhali 3814, Bangladesh
| | - Mohammad Salim Hossain
- Department of Pharmacy, Noakhali Science and Technology University, Noakhali 3814, Bangladesh.
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Turolo S, Edefonti A, Mazzocchi A, Syren ML, Morello W, Agostoni C, Montini G. Role of Arachidonic Acid and Its Metabolites in the Biological and Clinical Manifestations of Idiopathic Nephrotic Syndrome. Int J Mol Sci 2021; 22:5452. [PMID: 34064238 PMCID: PMC8196840 DOI: 10.3390/ijms22115452] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2021] [Revised: 05/17/2021] [Accepted: 05/18/2021] [Indexed: 11/17/2022] Open
Abstract
Studies concerning the role of arachidonic acid (AA) and its metabolites in kidney disease are scarce, and this applies in particular to idiopathic nephrotic syndrome (INS). INS is one of the most frequent glomerular diseases in childhood; it is characterized by T-lymphocyte dysfunction, alterations of pro- and anti-coagulant factor levels, and increased platelet count and aggregation, leading to thrombophilia. AA and its metabolites are involved in several biological processes. Herein, we describe the main fields where they may play a significant role, particularly as it pertains to their effects on the kidney and the mechanisms underlying INS. AA and its metabolites influence cell membrane fluidity and permeability, modulate platelet activity and coagulation, regulate lymphocyte activity and inflammation, preserve the permeability of the glomerular barrier, influence podocyte physiology, and play a role in renal fibrosis. We also provide suggestions regarding dietary measures that are able to prevent an imbalance between arachidonic acid and its parental compound linoleic acid, in order to counteract the inflammatory state which characterizes numerous kidney diseases. On this basis, studies of AA in kidney disease appear as an important field to explore, with possible relevant results at the biological, dietary, and pharmacological level, in the final perspective for AA to modulate INS clinical manifestations.
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Affiliation(s)
- Stefano Turolo
- Fondazione IRCCS Ca’ Granda-Ospedale Maggiore Policlinico, Pediatric Nephrology, Dialysis and Transplant Unit, Via della Commenda 9, 20122 Milan, Italy; (A.E.); (W.M.); (G.M.)
| | - Alberto Edefonti
- Fondazione IRCCS Ca’ Granda-Ospedale Maggiore Policlinico, Pediatric Nephrology, Dialysis and Transplant Unit, Via della Commenda 9, 20122 Milan, Italy; (A.E.); (W.M.); (G.M.)
| | - Alessandra Mazzocchi
- Department of Clinical Sciences and Community Health, University of Milan, 20122 Milan, Italy; (A.M.); (M.L.S.); (C.A.)
| | - Marie Louise Syren
- Department of Clinical Sciences and Community Health, University of Milan, 20122 Milan, Italy; (A.M.); (M.L.S.); (C.A.)
| | - William Morello
- Fondazione IRCCS Ca’ Granda-Ospedale Maggiore Policlinico, Pediatric Nephrology, Dialysis and Transplant Unit, Via della Commenda 9, 20122 Milan, Italy; (A.E.); (W.M.); (G.M.)
| | - Carlo Agostoni
- Department of Clinical Sciences and Community Health, University of Milan, 20122 Milan, Italy; (A.M.); (M.L.S.); (C.A.)
- Fondazione IRCCS Ca’ Granda Ospedale Maggiore Policlinico, Pediatric Intermediate Care Unit, 20122 Milan, Italy
| | - Giovanni Montini
- Fondazione IRCCS Ca’ Granda-Ospedale Maggiore Policlinico, Pediatric Nephrology, Dialysis and Transplant Unit, Via della Commenda 9, 20122 Milan, Italy; (A.E.); (W.M.); (G.M.)
- Department of Clinical Sciences and Community Health, University of Milan, 20122 Milan, Italy; (A.M.); (M.L.S.); (C.A.)
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Bihari S, Bannard-Smith J, Bellomo R. Albumin as a drug: its biological effects beyond volume expansion. CRIT CARE RESUSC 2020; 22:257-265. [PMID: 32900333 PMCID: PMC10692529 DOI: 10.1016/s1441-2772(23)00394-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/06/2023]
Abstract
Albumin is the most abundant and perhaps most important protein in human blood. Research has identified many of albumin's possible roles in modulating acid-base balance, modifying inflammation, maintaining vascular endothelial integrity, and binding endogenous and exogenous compounds. Albumin plays a key role in the homeostasis of vascular endothelium, offering protection from inflammation and damage to the glycocalyx. Albumin binds a diverse range of compounds. It transports, delivers and clears drugs, plus it helps with uptake, storage and disposal of potentially harmful biological products. The biological effects of albumin in critical illness are incompletely understood, but may enhance its clinical role beyond use as an intravenous fluid. In this article, we summarise the evidence surrounding albumin's biological and physiological effects beyond its use for plasma volume expansion, and explore potential mechanistic effects of albumin as a disease modifier in patients with critical illness.
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Affiliation(s)
- Shailesh Bihari
- Intensive and Critical Care Unit, Flinders Medical Centre, Adelaide, SA, Australia. ,
| | - Jonathan Bannard-Smith
- Department of Critical Care, Manchester Royal Infirmary, Manchester University NHS Foundation Trust, Manchester, UK
| | - Rinaldo Bellomo
- Centre for Integrated Critical Care, University of Melbourne, Melbourne, VIC, Australia
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Rosenfeld CS, Cooke PS. Endocrine disruption through membrane estrogen receptors and novel pathways leading to rapid toxicological and epigenetic effects. J Steroid Biochem Mol Biol 2019; 187:106-117. [PMID: 30465854 PMCID: PMC6370520 DOI: 10.1016/j.jsbmb.2018.11.007] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/31/2018] [Revised: 10/31/2018] [Accepted: 11/18/2018] [Indexed: 01/08/2023]
Abstract
Estrogen binding to estrogen receptors (ESR) triggers signaling cascades within cells. Historically, a major emphasis has been characterizing estrogen-induced genomic actions resulting from binding to nuclear estrogen receptor 1 (nESR1). However, recent evidence indicates the first receptors estrogens encounter as they enter a cell, membrane ESR1 (mESR1), also play crucial roles. Membrane and nuclear ESR are derived from the same transcripts but the former are directed to the membrane via palmitoylation. Binding and activation of mESR1 leads to rapid fluctuations in cAMP and Ca+2 and stimulation of protein kinase pathways. Endocrine disrupting chemicals (EDC) that mimic 17β-estradiol can signal through mESR1 and elicit non-genomic effects. Most current EDC studies have focused on genomic actions via nESR1. However, increasing number of studies have begun to examine potential EDC effects mediated through mESR1, and some EDC might have higher potency for signaling through mESR1 than nESR1. The notion that such chemicals might also affect mESR1 signaling via palmitoylation and depalmitoylation pathways has also begun to gain currency. Recent development of transgenic mice that lack either mESR1 or nESR1, while retaining functional ESR1 in the other compartment, will allow more precise in vivo approaches to determine EDC effects through nESR1 and/or mESR1. It is increasingly becoming apparent in this quickly evolving field that EDC directly affect mESR and estrogen signaling, but such chemicals can also affect proportion of ESR reaching the membrane. Future EDC studies should be designed to consider the full range of effects through mESR alone and in combination with nESR.
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Affiliation(s)
- Cheryl S Rosenfeld
- Bond Life Sciences Center, University of Missouri, Columbia, MO, 65211, USA; Biomedical Sciences, University of Missouri, Columbia, MO, 65211, USA; Thompson Center for Autism and Neurobehavioral Disorders, Columbia, MO, 65211, USA.
| | - Paul S Cooke
- Department of Physiological Sciences, University of Florida, Gainesville, FL, 32610, USA.
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Yamaguchi J, Kinoshita K, Ihara S, Furukawa M, Sakurai A. The Clinical Significance of Low Serum Arachidonic Acid in Sepsis Patients with Hypoalbuminemia. Intern Med 2018; 57:1833-1840. [PMID: 29491308 PMCID: PMC6064683 DOI: 10.2169/internalmedicine.9124-17] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
Objectives Fatty acids (FAs) have various roles in pro-inflammatory and anti-inflammatory functions. Hypoalbuminemia is often observed in sepsis patients. An imbalance among these compounds formed from FAs caused by hypoalbuminemia may be related to increased mortality in sepsis patients. The purpose of this study was to investigate the correlations between serum albumin and FAs in sepsis and the outcome. Methods This study was an observational investigation. The clinical and laboratory data of sepsis patients were recorded and the Sequential Organ Failure Assessment (SOFA) score was calculated at admission. The serum arachidonic acid (AA), eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA) and dihomo-gamma-linolenic acid (DHLA) levels were also measured as FAs. The body mass index (BMI) was used to determine the general nutrition status. Results Two hundred sepsis patients were enrolled during the study period. No significant correlations were observed between the BMI and the SOFA score or the serum albumin level at admission. The FA levels of the non-survivors were significantly lower, but there were no significant differences in the EPA/AA levels of the survivors and non-survivors. A low serum albumin level was closely related to low AA (p<0.0001), EPA (p<0.0001), DHA (p=0.0003), and DHLA levels (p<0.0001). A multiple logistic-regression analysis revealed that a high SOFA score [adjusted odds ratio, 1.19; 95% confidence interval (CI), 1.02-1.39, p=0.026] and low AA (adjusted odds ratio, 0.98; 95% CI, 0.978-0.994, p=0.041) were associated with a poor outcome. Conclusion A lower AA level was an important determinant of the outcome of patients with sepsis. These findings are consistent with the findings of previous studies, which reported that hypoalbuminemia might alter the AA metabolism in sepsis patients.
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Affiliation(s)
- Junko Yamaguchi
- Division of Emergency and Critical Care Medicine, Department of Acute Medicine, Nihon University School of Medicine, Japan
| | - Kosaku Kinoshita
- Division of Emergency and Critical Care Medicine, Department of Acute Medicine, Nihon University School of Medicine, Japan
| | - Shingo Ihara
- Division of Emergency and Critical Care Medicine, Department of Acute Medicine, Nihon University School of Medicine, Japan
| | - Makoto Furukawa
- Division of Emergency and Critical Care Medicine, Department of Acute Medicine, Nihon University School of Medicine, Japan
| | - Atsushi Sakurai
- Division of Emergency and Critical Care Medicine, Department of Acute Medicine, Nihon University School of Medicine, Japan
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Aliwarga T, Evangelista EA, Sotoodehnia N, Lemaitre RN, Totah RA. Regulation of CYP2J2 and EET Levels in Cardiac Disease and Diabetes. Int J Mol Sci 2018; 19:E1916. [PMID: 29966295 PMCID: PMC6073148 DOI: 10.3390/ijms19071916] [Citation(s) in RCA: 36] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2018] [Revised: 06/24/2018] [Accepted: 06/25/2018] [Indexed: 12/13/2022] Open
Abstract
Cytochrome P450 2J2 (CYP2J2) is a known arachidonic acid (AA) epoxygenase that mediates the formation of four bioactive regioisomers of cis-epoxyeicosatrienoic acids (EETs). Although its expression in the liver is low, CYP2J2 is mainly observed in extrahepatic tissues, including the small intestine, pancreas, lung, and heart. Changes in CYP2J2 levels or activity by xenobiotics, disease states, or polymorphisms are proposed to lead to various organ dysfunctions. Several studies have investigated the regulation of CYP2J2 and EET formation in various cell lines and have demonstrated that such regulation is tissue-dependent. In addition, studies linking CYP2J2 polymorphisms to the risk of developing cardiovascular disease (CVD) yielded contradictory results. This review will focus on the mechanisms of regulation of CYP2J2 by inducers, inhibitors, and oxidative stress modeling certain disease states in various cell lines and tissues. The implication of CYP2J2 expression, polymorphisms, activity and, as a result, EET levels in the pathophysiology of diabetes and CVD will also be discussed.
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Affiliation(s)
- Theresa Aliwarga
- Department of Medicinal Chemistry, University of Washington, Seattle, WA 98101, USA.
| | - Eric A Evangelista
- Department of Medicinal Chemistry, University of Washington, Seattle, WA 98101, USA.
| | - Nona Sotoodehnia
- Cardiovascular Health Research Unit, University of Washington, Seattle, WA 98195, USA.
- Department of Medicine, University of Washington, Seattle, WA 98195, USA.
- Division of Cardiology, University of Washington, Seattle, WA 98195, USA.
| | - Rozenn N Lemaitre
- Cardiovascular Health Research Unit, University of Washington, Seattle, WA 98195, USA.
| | - Rheem A Totah
- Department of Medicinal Chemistry, University of Washington, Seattle, WA 98101, USA.
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Wilkenfeld SR, Lin C, Frigo DE. Communication between genomic and non-genomic signaling events coordinate steroid hormone actions. Steroids 2018; 133:2-7. [PMID: 29155216 PMCID: PMC5864526 DOI: 10.1016/j.steroids.2017.11.005] [Citation(s) in RCA: 68] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/02/2017] [Revised: 11/07/2017] [Accepted: 11/10/2017] [Indexed: 01/30/2023]
Abstract
Steroid hormones are lipophilic molecules produced in one cell that can travel great distances within the body to elicit biological effects in another cell. In the canonical pathway, steroid hormone binding to a nuclear receptor (NR), often in the cytoplasm, causes the receptor to undergo a conformational change and translocate to the nucleus, where it interacts with specific sequences of DNA to regulate transcription. In addition to the classical genomic mechanism of action, alternate mechanisms of steroid activity have emerged that involve rapid, non-genomic signaling. The distinction between these two major mechanisms of action lies in the subcellular location of the initiating steroid hormone action. Importantly, the mechanisms of action are not exclusive, in that each can affect the activity of the other. Here, we describe the different types of genomic and non-genomic steroid hormone signaling mechanisms and how they can influence one another to ultimately regulate biology. Further, we discuss the approaches being used to study the non-genomic signaling events and address important caveats to be considered when designing new experiments. Thus, this minireview can serve as an introduction to the diverse signaling mechanisms of steroid hormones and offers initial, experimental guidance to those entering the field.
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Affiliation(s)
- Sandi R Wilkenfeld
- Department of Cancer Systems Imaging, The University of Texas MD Anderson Cancer Center, Houston, TX, USA; The University of Texas MD Anderson Cancer Center UTHealth Graduate School of Biomedical Sciences, Houston, TX, USA
| | - Chenchu Lin
- Center for Nuclear Receptors and Cell Signaling, University of Houston, Houston, TX, USA; Department of Biology and Biochemistry, University of Houston, Houston, TX, USA
| | - Daniel E Frigo
- Department of Cancer Systems Imaging, The University of Texas MD Anderson Cancer Center, Houston, TX, USA; Center for Nuclear Receptors and Cell Signaling, University of Houston, Houston, TX, USA; Department of Biology and Biochemistry, University of Houston, Houston, TX, USA; Department of Genitourinary Medical Oncology, The University of Texas MD Anderson Cancer Center, Houston, TX, USA; Molecular Medicine Program, The Houston Methodist Research Institute, Houston, TX, USA.
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Kumar D, Behal S, Bhattacharyya R, Banerjee D. Pseudoesterase activity of albumin: A probable determinant of cholesterol biosynthesis. Med Hypotheses 2018; 115:42-45. [PMID: 29685194 DOI: 10.1016/j.mehy.2018.03.018] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2017] [Revised: 03/27/2018] [Accepted: 03/29/2018] [Indexed: 11/28/2022]
Abstract
The association between hypoalbuminemia and coronary artery disease is known from some time. However, the reason as to how such phenomenon is correlated remains unknown. We have observed from published scientific literature that HSA has the potential to control cholesterol biosynthesis due to its pseudoesterase activity. In-silico observations have supported our view since acetyl coA, the precursor molecule of cholesterol biosynthesis is shown to bind with Tyr 411 of HSA. Incidentally, Tyr411 is a critical moiety for pseudoesterase activity of albumin. With this frame of reference in mind we hypothesize that pseudoesterase activity of HSA is an important determinant of lipid metabolism including cholesterol biosynthesis. Therefore, albumin has the potential to influence the atherosclerotic state important for pathogenesis of coronary artery diseases.
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Affiliation(s)
- Deepak Kumar
- Department of Experimental Medicine and Biotechnology, Postgraduate Institute of Medical Education and Research, Chandigarh 160012, India
| | - Sakshi Behal
- Department of Medical Microbiology, Postgraduate Institute of Medical Education and Research, Chandigarh 160012, India
| | - Rajasri Bhattacharyya
- Department of Experimental Medicine and Biotechnology, Postgraduate Institute of Medical Education and Research, Chandigarh 160012, India
| | - Dibyajyoti Banerjee
- Department of Experimental Medicine and Biotechnology, Postgraduate Institute of Medical Education and Research, Chandigarh 160012, India.
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Role of the cell membrane interface in modulating production and uptake of Alzheimer's beta amyloid protein. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2018; 1860:1639-1651. [PMID: 29572033 DOI: 10.1016/j.bbamem.2018.03.015] [Citation(s) in RCA: 41] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/04/2018] [Revised: 03/13/2018] [Accepted: 03/14/2018] [Indexed: 12/22/2022]
Abstract
The beta amyloid protein (Aβ) plays a central role in Alzheimer's disease (AD) pathogenesis and its interaction with cell membranes in known to promote mutually disruptive structural perturbations that contribute to amyloid deposition and neurodegeneration in the brain. In addition to protein aggregation at the membrane interface and disruption of membrane integrity, growing reports demonstrate an important role for the membrane in modulating Aβ production and uptake into cells. The aim of this review is to highlight and summarize recent literature that have contributed insight into the implications of altered membrane composition on amyloid precursor protein (APP) proteolysis, production of Aβ, its internalization in to cells via permeabilization and receptor mediated uptake. Here, we also review the various membrane model systems and experimental tools used for probing Aβ-membrane interactions to investigate the key mechanistic aspects underlying the accumulation and toxicity of Aβ in AD.
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Torres-Vergara P, Penny J. Pro-inflammatory and anti-inflammatory compounds exert similar effects on P-glycoprotein in blood–brain barrier endothelial cells. J Pharm Pharmacol 2018; 70:713-722. [DOI: 10.1111/jphp.12893] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2017] [Accepted: 01/12/2018] [Indexed: 12/13/2022]
Abstract
Abstract
Objectives
The effects of anti-inflammatory glucocorticoids dexamethasone (DX) and hydrocortisone (HC), pro-inflammatory cytokine interleukin-1β (IL-1β) and dietary long-chain polyunsaturated fatty acids (PUFAs) on expression and activity of the ATP-binding cassette transporter P-glycoprotein (P-GP) were studied in porcine brain endothelial cells (PBECs).
Methods
Primary PBECs were treated for 24 h with glucocorticoids, IL-1β and long-chain PUFAs. P-GP activity was determined by measuring intracellular calcein accumulation and P-GP expression by Western blotting. The effect of PUFAs on membrane fluidity was assessed by fluorescence recovery after photobleaching (FRAP).
Key findings
Dexamethasone, HC and IL-1β significantly increased P-GP expression and activity. The effect of IL-1β was attenuated by the IL-1 receptor antagonist (IL-1RA). This is the first report of the combined actions of IL-1β and IL-1RA on P-GP expression and the first evidence of glucocorticoid-mediated P-GP up-regulation in PBECs. Arachidonic acid (AA), docosahexaenoic acid (DHA) and eicosapentenoic acid (EPA) significantly decreased P-GP activity without affecting expression or membrane fluidity. AA, DHA and EPA counteracted IL-1β-mediated increases in P-GP activity, while AA and EPA, but not DHA, counteracted glucocorticoid-mediated increase in P-GP activity.
Conclusions
While glucocorticoids and IL-1β possess opposing actions in inflammation, they demonstrate functional consistency by increasing P-GP expression and activity in PBECs.
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Affiliation(s)
- Pablo Torres-Vergara
- Division of Pharmacy and Optometry, School of Health Sciences, Faculty of Medicine, Biology and Health, University of Manchester, Manchester, UK
- Department of Pharmacy, Faculty of Pharmacy, University of Concepción, Concepción, Chile
| | - Jeffrey Penny
- Division of Pharmacy and Optometry, School of Health Sciences, Faculty of Medicine, Biology and Health, University of Manchester, Manchester, UK
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Arachidonic acid: Physiological roles and potential health benefits - A review. J Adv Res 2017; 11:33-41. [PMID: 30034874 PMCID: PMC6052655 DOI: 10.1016/j.jare.2017.11.004] [Citation(s) in RCA: 323] [Impact Index Per Article: 46.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2017] [Revised: 11/16/2017] [Accepted: 11/17/2017] [Indexed: 12/17/2022] Open
Abstract
It is time to shift the arachidonic acid (ARA) paradigm from a harm-generating molecule to its status of polyunsaturated fatty acid essential for normal health. ARA is an integral constituent of biological cell membrane, conferring it with fluidity and flexibility, so necessary for the function of all cells, especially in nervous system, skeletal muscle, and immune system. Arachidonic acid is obtained from food or by desaturation and chain elongation of the plant-rich essential fatty acid, linoleic acid. Free ARA modulates the function of ion channels, several receptors and enzymes, via activation as well as inhibition. That explains its fundamental role in the proper function of the brain and muscles and its protective potential against Schistosoma mansoni and S. haematobium infection and tumor initiation, development, and metastasis. Arachidonic acid in cell membranes undergoes reacylation/deacylation cycles, which keep the concentration of free ARA in cells at a very low level and limit ARA availability to oxidation. Metabolites derived from ARA oxidation do not initiate but contribute to inflammation and most importantly lead to the generation of mediators responsible for resolving inflammation and wound healing. Endocannabinoids are oxidation-independent ARA derivatives, critically important for brain reward signaling, motivational processes, emotion, stress responses, pain, and energy balance. Free ARA and metabolites promote and modulate type 2 immune responses, which are critically important in resistance to parasites and allergens insult, directly via action on eosinophils, basophils, and mast cells and indirectly by binding to specific receptors on innate lymphoid cells. In conclusion, the present review advocates the innumerable ARA roles and considerable importance for normal health.
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Gantz SC, Bean BP. Cell-Autonomous Excitation of Midbrain Dopamine Neurons by Endocannabinoid-Dependent Lipid Signaling. Neuron 2017; 93:1375-1387.e2. [PMID: 28262417 DOI: 10.1016/j.neuron.2017.02.025] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2016] [Revised: 11/28/2016] [Accepted: 02/09/2017] [Indexed: 01/13/2023]
Abstract
The major endocannabinoid in the mammalian brain is the bioactive lipid 2-arachidonoylglycerol (2-AG). The best-known effects of 2-AG are mediated by G-protein-coupled cannabinoid receptors. In principle, 2-AG could modify neuronal excitability by acting directly on ion channels, but such mechanisms are poorly understood. Using a preparation of dissociated mouse midbrain dopamine neurons to isolate effects on intrinsic excitability, we found that 100 nM 2-AG accelerated pacemaking and steepened the frequency-current relationship for burst-like firing. In voltage-clamp experiments, 2-AG reduced A-type potassium current (IA) through a cannabinoid receptor-independent mechanism mimicked by arachidonic acid, which has no activity on cannabinoid receptors. Activation of orexin, neurotensin, and metabotropic glutamate Gq/11-linked receptors mimicked the effects of exogenous 2-AG and their actions were prevented by inhibiting the 2-AG-synthesizing enzyme diacylglycerol lipase α. The results show that 2-AG and related lipid signaling molecules can directly tune neuronal excitability in a cell-autonomous manner by modulating IA.
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Affiliation(s)
- Stephanie C Gantz
- Department of Neurobiology, Harvard Medical School, Boston, MA 02115, USA.
| | - Bruce P Bean
- Department of Neurobiology, Harvard Medical School, Boston, MA 02115, USA.
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16
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Pompeani N, Rybalka E, Latchman H, Murphy RM, Croft K, Hayes A. Skeletal muscle atrophy in sedentary Zucker obese rats is not caused by calpain-mediated muscle damage or lipid peroxidation induced by oxidative stress. J Negat Results Biomed 2014; 13:19. [PMID: 25547587 PMCID: PMC4296544 DOI: 10.1186/s12952-014-0019-z] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2014] [Accepted: 12/12/2014] [Indexed: 11/10/2022] Open
Abstract
Background Skeletal muscle undergoes significant atrophy in Type 2 diabetic patients and animal models. We aimed to determine if atrophy of Zucker rat skeletal muscle was due to the activation of intracellular damage pathways induced by excess reactive oxygen species production (specifically those associated with the peroxidation of lipid membranes) and calpain activity. 14 week old obese Zucker rats and littermate lean controls were injected with 1% Evan’s Blue Dye. Animals were anaesthetised and extensor digitorum longus and soleus muscles were dissected, snap frozen and analysed for ROS-mediated F2-isoprostane production and calpain activation/autolysis. Contralateral muscles were histologically analysed for markers of muscle membrane permeability and atrophy. Results Muscle mass was lower in extensor digitorum longus and soleus of obese compared with lean animals, concomitant with reduced fibre area. Muscles from obese rats had a higher proportional area of Evan’s Blue Dye fluorescence, albeit this was localised to the interstitium/external sarcolemma. There were no differences in F2-isoprostane production when expressed relative to arachidonic acid content, which was lower in the obese EDL and soleus muscles. There were no differences in the activation of either μ-calpain or calpain-3. Conclusions This study highlights that atrophy of Zucker rat skeletal muscle is not related to sarcolemmal damage, sustained hyperactivation of the calpain proteases or excessive lipid peroxidation. As such, establishing the correct pathways involved in atrophy is highly important so as to develop more specific treatment options that target the underlying cause. This study has eliminated two of the potential pathways theorised to be responsible.
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Affiliation(s)
- Nancy Pompeani
- Centre for Chronic Disease, College of Health and Biomedicine, Victoria University, Melbourne, Australia.
| | - Emma Rybalka
- Centre for Chronic Disease, College of Health and Biomedicine, Victoria University, Melbourne, Australia. .,Institute of Sport, Exercise and Active Living (ISEAL), Victoria University, Melbourne, Australia.
| | - Heidy Latchman
- Department of Zoology, La Trobe University, Melbourne, Australia.
| | - Robyn M Murphy
- Department of Zoology, La Trobe University, Melbourne, Australia.
| | - Kevin Croft
- School of Medicine and Pharmacology, University of Western Australia, Perth, Australia.
| | - Alan Hayes
- Centre for Chronic Disease, College of Health and Biomedicine, Victoria University, Melbourne, Australia. .,Institute of Sport, Exercise and Active Living (ISEAL), Victoria University, Melbourne, Australia.
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Das UN. Nutritional factors in the prevention and management of coronary artery disease and heart failure. Nutrition 2014; 31:283-91. [PMID: 25592005 DOI: 10.1016/j.nut.2014.08.011] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2014] [Revised: 08/18/2014] [Accepted: 08/18/2014] [Indexed: 11/26/2022]
Abstract
Nutritional factors such as magnesium, folic acid, vitamins B12 and B6, L-arginine, and polyunsaturated fatty acids (PUFAs) appear to be significantly beneficial for patients with coronary artery disease (CAD), and in the prevention and arresting the progression of HF and cardiac arrhythmias. Additionally, ingestion of adequate amounts of protein and maintaining normal concentrations of plasma albumin seem to be essential for these patients. These nutrients closely interact with the metabolism of L-arginine-nitric oxide (NO) system, essential fatty acids, and eicosanoids such that beneficial products such as NO, prostaglandin E1, prostacyclin, prostaglandin I3, lipoxins, resolvins, and protectins are generated and synthesis of proinflammatory cytokines is suppressed that results in platelet anti-aggregation, vasodilation, angiogenesis, and prevention of CAD, cardiac arrhythmias, and stabilization of HF. This implies that individuals at high risk for CAD, cardiac arrhythmias, and HF and those who have these diseases need to be screened for plasma levels of magnesium, folic acid, vitamins B12 and B6, L-arginine, NO, various PUFAs, lipoxin A4, resolvins, protectins, asymmetrical dimethylarginine (an endogenous inhibitor of NO), albumin, and various eicosanoids and cytokines and correct their abnormalities to restore normal physiology.
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Affiliation(s)
- Undurti N Das
- UND Life Sciences, Federal Way, WA, USA and Department of Medicine and BioScience Research Centre, Gayatri Vidya Parishad Hospital, Campus of GVP College of Engineering, Visakhapatnam, India.
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Hypercholesterolemia Increases Plasma Saturated and n-6 Fatty Acids Altering Prostaglandin Homeostasis and Promotes Endothelial Dysfunction in Rabbits. Lipids 2014; 49:685-93. [DOI: 10.1007/s11745-014-3915-6] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2014] [Accepted: 05/13/2014] [Indexed: 11/26/2022]
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19
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Cellular membrane fluidity in amyloid precursor protein processing. Mol Neurobiol 2014; 50:119-29. [PMID: 24553856 DOI: 10.1007/s12035-014-8652-6] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2013] [Accepted: 01/23/2014] [Indexed: 12/20/2022]
Abstract
The senile plaque is a pathologic hallmark of Alzheimer's disease (AD). Amyloid-β peptide (Aβ), the main constituent of senile plaques, is neurotoxic especially in its oligomeric form. Aβ is derived from the sequential cleavage of amyloid precursor protein (APP) by β- and γ-secretases in the amyloidogenic pathway. Alternatively, APP can be cleaved by α-secretases within the Aβ domain to produce neurotrophic and neuroprotective α-secretase-cleaved soluble APP (sAPPα) in the nonamyloidogenic pathway. Since APP and α-, β-, and γ-secretases are membrane proteins, APP processing should be highly dependent on the membrane composition and the biophysical properties of cellular membrane. In this review, we discuss the role of the biophysical properties of cellular membrane in APP processing, especially the effects of phospholipases A(2) (PLA(2)s), fatty acids, cholesterol, and Aβ on membrane fluidity in relation to their effects on APP processing.
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20
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Zhang C, Zheng Y, Chen L, Chen M, Liang S, Lin M, Luo D. Regulation of basal lateral membrane mobility and permeability to divalent cations by membrane associated-protein kinase C. PLoS One 2013; 8:e80291. [PMID: 24260363 PMCID: PMC3832666 DOI: 10.1371/journal.pone.0080291] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2013] [Accepted: 10/01/2013] [Indexed: 11/19/2022] Open
Abstract
Biological membrane stabilization is essential for maintenance of cellular homeostasis, functionality and appropriate response to various stimuli. Previous studies have showed that accumulation of PKCs in the cell membrane significantly downregulates the membrane fluidity and Ca2+ influxes through the membranes in activated cells. In addition, membrane-inserted form of PKCs has been found in a variety of resting mammalian cells and tissues. This study is aimed to investigate possible role of the endogenous membrane-associated PKCs in the modulation of basal membrane fluidity. Here, we showed that interfering PKC expression by chronic activation of PKC with phorbol myristate acetate (PMA) or shRNA targeting at PKCα lowered the levels of PKCα in cytosol, peripheral membrane and integral membrane pools, while short-term activation of PKC with PMA induced accumulation of PKCα in the membrane pool accompanied by a dramatic decrease in the cytosol fraction. The lateral membrane mobility increased or decreased in accordance with the abundance alterations in the membrane-associated PKCα by these treatments. In addition, membrane permeability to divalent cations including Ca2+, Mn2+ and Ba2+ were also potentiated or abrogated along with the changes in PKC expression on the plasma membrane. Membrane stabilizer ursodeoxycholate abolished both of the enhanced lateral membrane mobility and permeability to divalent cations due to PKCα deficiency, whereas Gö6983, a PKC antagonist, or Gd3+ and 2-aminoethyoxydipheyl borne, two Ca2+ channels blockers, showed no effect, suggesting that this PKC-related regulation is independent of PKC activation or a modulation of specific divalent cation channel. Thus, these data demonstrate that the native membrane-associated PKCα is involved in the maintenance of basal membrane stabilization in resting cells.
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Affiliation(s)
- Chao Zhang
- Department of Pharmacology, School of Chemical Biology & Pharmaceutical Sciences, Capital Medical University, Beijing, P.R. China
| | - Yuanyuan Zheng
- Department of Pharmacology, School of Chemical Biology & Pharmaceutical Sciences, Capital Medical University, Beijing, P.R. China
| | - Lihong Chen
- Department of Pharmacology, School of Chemical Biology & Pharmaceutical Sciences, Capital Medical University, Beijing, P.R. China
| | - Min Chen
- Department of Pharmacology, School of Chemical Biology & Pharmaceutical Sciences, Capital Medical University, Beijing, P.R. China
| | - Shenxuan Liang
- Department of Pharmacology, School of Chemical Biology & Pharmaceutical Sciences, Capital Medical University, Beijing, P.R. China
| | - Mosi Lin
- Department of Pharmacology, School of Chemical Biology & Pharmaceutical Sciences, Capital Medical University, Beijing, P.R. China
| | - Dali Luo
- Department of Pharmacology, School of Chemical Biology & Pharmaceutical Sciences, Capital Medical University, Beijing, P.R. China
- * E-mail:
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21
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Said T, Tremblay-Mercier J, Berrougui H, Rat P, Khalil A. Effects of vegetable oils on biochemical and biophysical properties of membrane retinal pigment epithelium cells. Can J Physiol Pharmacol 2013; 91:812-7. [PMID: 24144052 DOI: 10.1139/cjpp-2013-0036] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The aim of this study was to investigate the effect of vegetable oil enrichment of retinal pigment epithelial (RPE) cells on their biochemical and biophysical properties. For this, RPE cells were incubated with 4 different vegetables oils (olive oil, corn oil, argan oil, and camelina oil). The cytotoxicity of these vegetable oils was assessed in vivo on 8-week-old mice and in vitro by using the neutral red and YO-PRO-1 tests. Membrane fluidity was evaluated by fluorescence anisotropy using the fluorescent probe diphenylhexatriene, and membrane fatty acid composition was assessed by gas chromatography. None of the oils tested displayed cytotoxic effects. In vitro, omega-3 rich oils improved membrane fluidity by 47% compared with the control cells. The omega-3 PUFA content within membranes decreased by 38% to 55% when cells were incubated separately with olive oil, corn oil, or argan oil, and increased when cells were incubated with a mixture of those oils, or with camelina oil alone (50% and 103% increase, respectively). Our results show that the fatty acids in vegetable oil incorporate into retinal cells and increase the plasma membrane fluidity.
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Affiliation(s)
- Toihiri Said
- a Research Center on Aging, Fleurimont Site, 3001, 12ème Avenue Nord, Sherbrooke, QC J1H 4N4, Canada
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22
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Marandykina A, Palacios-Prado N, Rimkutė L, Skeberdis VA, Bukauskas FF. Regulation of connexin36 gap junction channels by n-alkanols and arachidonic acid. J Physiol 2013; 591:2087-101. [PMID: 23420660 PMCID: PMC3634521 DOI: 10.1113/jphysiol.2013.250910] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2013] [Accepted: 02/13/2013] [Indexed: 12/18/2022] Open
Abstract
We examined junctional conductance (gj) and its dependence on transjunctional voltage in gap junction (GJ) channels formed of wild-type connexin36 (Cx36) or its fusion form with green fluorescent protein (Cx36-EGFP) transfected in HeLa cells or endogenously expressed in primary culture of pancreatic β-cells. Only a very small fraction (∼0.8%) of Cx36-EGFP channels assembled into junctional plaques of GJs were open under control conditions. We found that short carbon chain n-alkanols (SCCAs) increased gj, while long carbon chain n-alkanols resulted in full uncoupling; cutoff is between heptanol and octanol. The fraction of functional channels and gj increased several fold under an exposure to SCCAs, or during reduction of endogenous levels of arachidonic acid (AA) by exposure to fatty acid-free BSA or cytosolic phospholipase A2 inhibitors. Moreover, uncoupling caused by exogenously applied AA can be rescued by BSA, which binds AA and other polyunsaturated fatty acids (PUFAs), but not by BSA modified with 1,2-cyclohexanedione, which does not bind AA and other PUFAs. We propose that under control conditions, Cx36 GJ channels in HeLa transfectants and β-cells are inhibited by endogenous AA, which stabilizes a closed conformational state of the channel that leads to extremely low fraction of functional channels. In addition, SCCAs increase gj by interfering with endogenous AA-dependent inhibition, increasing open probability and the fraction of functional channels.
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Affiliation(s)
- Alina Marandykina
- Dominick P. Purpura Department of Neuroscience, Albert Einstein College of Medicine, Bronx, NY 10461, USA
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Abstract
PURPOSE The most recent published evidence on the use of colloids versus crystalloids in critical care is reviewed, with a focus on population-dependent differences in safety and efficacy. SUMMARY Colloids offer a number of theoretical advantages over crystalloids for fluid resuscitation, but some colloids (e.g., hydroxyethyl starch solutions, dextrans) can have serious adverse effects, and albumin products entail higher costs. The results of the influential Saline Versus Albumin Fluid Evaluation (SAFE) trial and a subsequent SAFE subgroup analysis indicated that colloid therapy should not be used in patients with traumatic brain injury and other forms of trauma due to an increased mortality risk relative to crystalloid therapy. With regard to patients with severe sepsis, two meta-analyses published in 2011, which collectively evaluated 82 trials involving nearly 10,000 patients, indicated comparable outcomes with the use of either crystalloids or albumins. For patients requiring extracorporeal cardiopulmonary bypass (CPB) during heart surgery, the available evidence supports the use of a colloid, particularly albumin, for CPB circuit priming and postoperative volume expansion. In select patients with burn injury, the published evidence supports the use of supplemental colloids if adequate urine output cannot be maintained with a crystalloid-only rescue strategy. CONCLUSION The results of the SAFE trial and a subgroup analysis of SAFE data suggest that colloids should be avoided in patients with trauma and traumatic brain injury. There are minimal differences in outcome between crystalloids and hypo-oncotic or iso-oncotic albumin for fluid resuscitation in severe sepsis; in select populations, such as patients undergoing cardiac surgery, the use of iso-oncotic albumin may confer a survival advantage and should be considered a first-line alternative.
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Affiliation(s)
- Rachel M Kruer
- Surgical Intensive Care, The Johns Hopkins Hospital, Baltimore, MD 21287-6180, USA.
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24
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Qu BX, Gong Y, Sinclair D, Fu M, Perl D, Diaz-Arrastia R. cPLA2α knockout mice exhibit abnormalities in the architecture and synapses of cortical neurons. Brain Res 2012; 1497:101-5. [PMID: 23266724 DOI: 10.1016/j.brainres.2012.12.018] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2012] [Revised: 12/11/2012] [Accepted: 12/13/2012] [Indexed: 10/27/2022]
Abstract
Cytosolic phospholipase A2α (cPLA2α) affects membrane fluidity and permeability by catalyzing the hydrolysis of membrane phospholipids. We hypothesize that cPLA2α deficiency induces rigidity and architectural changes in cell membranes, especially in large cortical neurons. These membrane changes are discernible using light and electron microscopy. Through careful comparison with wild-type counterparts, we observed significant morphological changes in cortical neurons of cPLA2α knockout mice. These changes included the following: (1) increased numbers of nucleoli and enlarged nuclei, (2) narrower spaces between the inner and outer nuclear membranes, (3) reduced numbers of nuclear pores and altered nuclear pore structure, and (4) morphological changes in synaptic clefts. These results further suggest that cPLA2α and its cleaved arachidonic acids play important roles in cortical neuronal maturation and in normal neurochemical processes.
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Affiliation(s)
- Bao-Xi Qu
- Department of Neurology, Center for Neuroscience and Regenerative Medicine, Uniformed Services University of Health Sciences, Rockville, MD 20852, USA.
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25
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Extra-virgin olive oil consumption improves the capacity of HDL to mediate cholesterol efflux and increases ABCA1 and ABCG1 expression in human macrophages. Br J Nutr 2012; 109:1844-55. [DOI: 10.1017/s0007114512003856] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
The present study was aimed to investigate the effect of 12 weeks of extra-virgin olive oil (EVOO) consumption on the capacity of HDL to promote cholesterol efflux (CE) and to determine which CE pathways are modulated by EVOO consumption. Whole HDL and HDL2/HDL3 subclasses were isolated from the plasma of twenty-six healthy volunteers before and after 12 weeks of EVOO consumption (25 ml/d). EVOO consumption increased the capacity of serum and HDL to mediate CE from THP-1, J774 macrophages and Fu5AH cells by 9·8–24·57 %, depending on the cell type. The increase in CE was independent of both HDL concentration and subclass distribution. The three HDL-mediated CE pathways (ATP-binding cassette (ABC) A1, ABCG1 and scavenger receptor class B type I (SR-BI)) were modulated by EVOO consumption. The fluidity of the phospholipidic layer of HDL increased by 13 % (P< 0·001) following EVOO consumption compared with baseline. EVOO consumption also increased the release of excess cholesterol from human monocyte-derived macrophages (HMDM) by 44 % (P< 0·001), and ABCA1 and ABCG1 mRNA transcription by 16·08 % (P< 0·001) and 35·79 % (P< 0·01), respectively. The protein expression of these two cholesterol transporters also increased after EVOO consumption. In contrast, SR-BI mRNA and protein expression in HMDM were significantly lower after 12 weeks of EVOO consumption. Incubating J774 macrophages with EVOO polyphenol extracts induced a concentration-dependent up-regulation of ABCA1 and ABCG1 expression in macrophages. After 12 weeks of EVOO consumption, the capacity of HDL to mediate CE was improved and the ability of HMDM to release excess cholesterol was enhanced by increasing the expression of ABCA1 and ABCG1 transporters.
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Shearer KE, Rickert EL, Peterson AC, Weatherman RV. Dissecting rapid estrogen signaling with conjugates. Steroids 2012; 77:968-73. [PMID: 22417626 PMCID: PMC3382051 DOI: 10.1016/j.steroids.2012.02.021] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/04/2011] [Revised: 02/18/2012] [Accepted: 02/24/2012] [Indexed: 10/28/2022]
Abstract
Hypothesizing that rapid estrogen signaling could be modulated from different estrogen receptors with unique localization patterns, a number of groups have attempted to design drug conjugates that target or restrict compounds to specific subcellular compartments. This article will briefly discuss the history of using conjugates to dissect rapid estrogen signaling and different strategies to attempt to target estrogens and antiestrogens to different locations. It will also detail some of the potential issues that can arise with different types of conjugates, using examples drawn from the authors' own work.
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Affiliation(s)
- Kati E. Shearer
- Department of Chemistry and Biochemistry, Rose-Hulman Institute of Technology, Terre Haute, IN. USA
| | - Emily L. Rickert
- Department of Medicinal Chemistry and Molecular Pharmacology, Purdue University, West Lafayette, IN. USA
| | - Anton C. Peterson
- Department of Medicinal Chemistry and Molecular Pharmacology, Purdue University, West Lafayette, IN. USA
| | - Ross V. Weatherman
- Department of Chemistry and Biochemistry, Rose-Hulman Institute of Technology, Terre Haute, IN. USA
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27
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Chen L, Meng Q, Yu X, Li C, Zhang C, Cui C, Luo D. Possible mechanisms underlying the biphasic regulatory effects of arachidonic acid on Ca2+ signaling in HEK293 cells. Cell Signal 2012; 24:1565-72. [PMID: 22484156 DOI: 10.1016/j.cellsig.2012.03.016] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/29/2012] [Revised: 03/21/2012] [Accepted: 03/21/2012] [Indexed: 12/01/2022]
Abstract
Arachidonic acid (AA), an endogenous lipid signal molecule released from membrane upon cell activation, modulates intracellular Ca(2+) ([Ca(2+)](i)) signaling positively and negatively. However, the mechanisms underlying the biphasic effects of AA are rather obscure. Using probes for measurements of [Ca(2+)](i) and fluidity of plasma membrane (PM)/endoplasmic reticulum (ER), immunostaining, immunoblotting and shRNA interference approaches, we found that AA at low concentration, 3 μM, reduced the PM fluidity by activating PKCα and PKCβII translocation to PM and also the ER fluidity directly. In accordance, 3 μM AA did not impact the basal [Ca(2+)](i) but significantly suppressed the thapsigargin-induced Ca(2+) release and Ca(2+) influx. Inhibition of PKC with Gö6983 or knockdown of PKCα or PKCβ using shRNA significantly attenuated the inhibitory effects of 3 μM AA on PM fluidity and agonist-induced Ca(2+) signal. However, AA at high concentration, 30 μM, caused robust release and entry of Ca(2+) accompanied by a facilitated PM fluidity but decreased ER fluidity and dramatic PKCβI and PKCβII redistribution in the ER. Compared with ursodeoxycholate acid, a membrane stabilizing agent that only inhibited the 30 μM AA-induced Ca(2+) influx by 45%, Gd(3+) at concentration of 10 μM could completely abolish both release and entry of Ca(2+) induced by AA, suggesting that the potentiated PM fluidity is not the only reason for AA eliciting Ca(2+) signal. Therefore, the study herein demonstrates that a lowered PM fluidity by PKC activation and a direct ER stabilization contribute significantly for AA downregulation of [Ca(2+)](i) response, while Gd(3+)-sensitive 'pores' in PM/ER play an important role in AA-induced Ca(2+) signal in HEK293 cells.
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Affiliation(s)
- Lihong Chen
- Department of Pharmacology, School of Chemical Biology & Pharmaceutical Sciences, Capital Medical University, Beijing, PR China
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Åhs M, Prasad A, Aminov Z, Carpenter DO. Mechanisms of cell death of thymocytes induced by polyunsaturated, monounsaturated and trans-fatty acids. J Cell Biochem 2011; 112:3863-71. [DOI: 10.1002/jcb.23319] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
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Cribbs SK, Martin GS. Fluid balance and colloid osmotic pressure in acute respiratory failure: optimizing therapy. Expert Rev Respir Med 2011; 3:651-62. [PMID: 20477354 DOI: 10.1586/ers.09.49] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Acute lung injury and acute respiratory distress syndrome continue to be major causes of morbidity and mortality in the intensive care unit due to a lack of specific effective therapy. Affecting nearly 200,000 people every year in the USA alone, patients with this syndrome often require extensive intensive care unit and hospital care, leading to enormous utilization of healthcare resources and significant expenditures, and ultimately leaving survivors with a reduced quality of life. A disease of altered capillary permeability, acute lung injury (ALI)/acute respiratory distress syndrome (ARDS) is characterized by significant fluid imbalances and oncotic pressure changes. Although investigations directed at these abnormalities may improve patient-centered outcomes, fluid management in ALI/ARDS continues to be a source of great controversy. In this review, we discuss fluid balance and the colloid osmotic pressure gradients in ALI/ARDS, followed by a review of the prognostic implications of increasing extravascular lung water, and conclude with contemporary approaches to optimizing therapy in this condition, including the role of albumin and diuretic therapy.
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Affiliation(s)
- Sushma K Cribbs
- Emory University School of Medicine, 1648 Pierce Drive, Atlanta, GA 30322, USA.
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30
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Askarova S, Yang X, Lee JCM. Impacts of membrane biophysics in Alzheimer's disease: from amyloid precursor protein processing to aβ Peptide-induced membrane changes. Int J Alzheimers Dis 2011; 2011:134971. [PMID: 21547213 PMCID: PMC3087431 DOI: 10.4061/2011/134971] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2010] [Revised: 12/30/2010] [Accepted: 01/21/2011] [Indexed: 12/11/2022] Open
Abstract
An increasing amount of evidence supports the notion that cytotoxic effects of amyloid-β peptide (Aβ), the main constituent of senile plaques in Alzheimer's disease (AD), are strongly associated with its ability to interact with membranes of neurons and other cerebral cells. Aβ is derived from amyloidogenic cleavage of amyloid precursor protein (AβPP) by β- and γ-secretase. In the nonamyloidogenic pathway, AβPP is cleaved by α-secretases. These two pathways compete with each other, and enhancing the non-amyloidogenic pathway has been suggested as a potential pharmacological approach for the treatment of AD. Since AβPP, α-, β-, and γ-secretases are membrane-associated proteins, AβPP processing and Aβ production can be affected by the membrane composition and properties. There is evidence that membrane composition and properties, in turn, play a critical role in Aβ cytotoxicity associated with its conformational changes and aggregation into oligomers and fibrils. Understanding the mechanisms leading to changes in a membrane's biophysical properties and how they affect AβPP processing and Aβ toxicity should prove to provide new therapeutic strategies for prevention and treatment of AD.
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Affiliation(s)
- Sholpan Askarova
- Department of Biological Engineering, University of Missouri, Columbia, MO 65211, USA
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31
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Pavan B, Paganetto G, Dalpiaz A, Biondi C, Lunghi L. Estrogen metabolites in the release of inflammatory mediators from human amnion-derived cells. Life Sci 2011; 88:551-8. [DOI: 10.1016/j.lfs.2011.01.018] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2010] [Revised: 12/07/2010] [Accepted: 01/06/2011] [Indexed: 01/10/2023]
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Effects of fatty acid unsaturation numbers on membrane fluidity and α-secretase-dependent amyloid precursor protein processing. Neurochem Int 2010; 58:321-9. [PMID: 21184792 DOI: 10.1016/j.neuint.2010.12.004] [Citation(s) in RCA: 134] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2010] [Revised: 10/17/2010] [Accepted: 12/07/2010] [Indexed: 12/19/2022]
Abstract
Fatty acids may integrate into cell membranes to change physical properties of cell membranes, and subsequently alter cell functions in an unsaturation number-dependent manner. To address the roles of fatty acid unsaturation numbers in cellular pathways of Alzheimer's disease (AD), we systematically investigated the effects of fatty acids on cell membrane fluidity and α-secretase-cleaved soluble amyloid precursor protein (sAPP(α)) secretion in relation to unsaturation numbers using stearic acid (SA, 18:0), oleic acid (OA, 18:1), linoleic acid (LA, 18:2), α-linolenic acid (ALA, 18:3), arachidonic acid (AA, 20:4), eicosapentaenoic acid (EPA, 20:5), and docosahexaenoic acid (DHA, 22:6). Treatments of differentiated human neuroblastoma (SH-SY5Y cells) with AA, EPA and DHA for 24h increased sAPP(α) secretion and membrane fluidity, whereas those treatments with SA, OA, LA and ALA did not. Treatments with AA and DHA did not alter the total expressions of amyloid precursor protein (APP) and α-secretases in SH-SY5Y cells. These results suggested that not all unsaturated fatty acids but only those with 4 or more double bonds, such as AA, EPA and DHA, are able to increase membrane fluidity and lead to increase in sAPP(α) secretion. This study provides insights into dietary strategies for the prevention of AD.
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A role for protein kinase C in the regulation of membrane fluidity and Ca²(+) flux at the endoplasmic reticulum and plasma membranes of HEK293 and Jurkat cells. Cell Signal 2010; 23:497-505. [PMID: 21062642 DOI: 10.1016/j.cellsig.2010.11.005] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2010] [Revised: 10/19/2010] [Accepted: 11/02/2010] [Indexed: 10/18/2022]
Abstract
Protein kinase C (PKC) plays a prominent role in the regulation of a variety of cellular functions, including Ca²(+) signalling. In HEK293 and Jurkat cells, the Ca²(+) release and Ca²(+) uptake stimulated by several different activators were attenuated by activation of PKC with phorbol myristate acetate (PMA) or 1-oleoyl-2-acetyl-sn-glycerol (OAG) and potentiated by PKC inhibition with Gö6983 or knockdown of PKCα or PKCβ using shRNA. Immunostaining and Western blotting analyses revealed that PKCα and PKCβII accumulated at the plasma membrane (PM) and that these isoforms, along with PKCβI, also translocated to the endoplasmic reticulum (ER) upon activation with PMA. Measurements of membrane fluidity showed that, like the cell membrane stabilizers bovine serum albumin (BSA) and ursodeoxycholate (UDCA), PMA and OAG significantly reduced the fluidity of both the PM and ER membranes; these effects were blocked in PKC-knockdown cells. Interestingly, both BSA and UDCA inhibited the Ca²(+) responses to agonists to the same extent as PMA, whereas Tween 20, which increases membrane fluidity, raised the internal Ca²(+) concentration. Thus, activation of PKC induces both translocation of PKC to the PM and ER membranes and downregulation of membrane fluidity, thereby negatively modulating Ca²(+) flux.
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Moskalenko AV, Yarova PL, Gordeev SN, Smirnov SV. Single protein molecule mapping with magnetic atomic force microscopy. Biophys J 2010; 98:478-87. [PMID: 20141762 PMCID: PMC2814202 DOI: 10.1016/j.bpj.2009.10.021] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2009] [Revised: 10/06/2009] [Accepted: 10/15/2009] [Indexed: 02/04/2023] Open
Abstract
Understanding the structural organization and distribution of proteins in biological cells is of fundamental importance in biomedical research. The use of conventional fluorescent microscopy for this purpose is limited due to its relatively low spatial resolution compared to the size of a single protein molecule. Atomic force microscopy (AFM), on the other hand, allows one to achieve single-protein resolution by scanning the cell surface using a specialized ligand-coated AFM tip. However, because this method relies on short-range interactions, it is limited to the detection of binding sites that are directly accessible to the AFM tip. We developed a method based on magnetic (long-range) interactions and applied it to investigate the structural organization and distribution of endothelin receptors on the surface of smooth muscle cells. Endothelin receptors were labeled with 50-nm superparamagnetic microbeads and then imaged with magnetic AFM. Considering its high spatial resolution and ability to "see" magnetically labeled proteins at a distance of up to 150 nm, this approach may become an important tool for investigating the dynamics of individual proteins both on the cell membrane and in the submembrane space.
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Affiliation(s)
| | - Polina L. Yarova
- Department of Pharmacy and Pharmacology, University of Bath, Bath, United Kingdom
| | | | - Sergey V. Smirnov
- Department of Pharmacy and Pharmacology, University of Bath, Bath, United Kingdom
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Yang X, Sheng W, He Y, Cui J, Haidekker MA, Sun GY, Lee JCM. Secretory phospholipase A2 type III enhances alpha-secretase-dependent amyloid precursor protein processing through alterations in membrane fluidity. J Lipid Res 2009; 51:957-66. [PMID: 19805624 DOI: 10.1194/jlr.m002287] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
Abstract
In the non-amyloidogenic pathway, amyloid precursor protein (APP) is cleaved by alpha-secretases to produce alpha-secretase-cleaved soluble APP (sAPP(alpha)) with neuroprotective and neurotrophic properties; therefore, enhancing the non-amyloidogenic pathway has been suggested as a potential pharmacological approach for the treatment of Alzheimer's disease. Here, we demonstrate the effects of type III secretory phospholipase A(2) (sPLA(2)-III) on sAPP(alpha) secretion. Exposing differentiated neuronal cells (SH-SY5Y cells and primary rat neurons) to sPLA(2)-III for 24 h increased sAPP(alpha) secretion and decreased levels of Abeta(1-42) in SH-SY5Y cells, and these changes were accompanied by increased membrane fluidity. We further tested whether sPLA(2)-III-enhanced sAPP(alpha) release is due in part to the production of its hydrolyzed products, including arachidonic acid (AA), palmitic acid (PA), and lysophosphatidylcholine (LPC). Addition of AA but neither PA nor LPC mimicked sPLA(2)-III-induced increases in sAPP(alpha) secretion and membrane fluidity. Treatment with sPLA(2)-III and AA increased accumulation of APP at the cell surface but did not alter total expressions of APP, alpha-secretases, and beta-site APP cleaving enzyme. Taken together, these results support the hypothesis that sPLA(2)-III enhances sAPP(alpha) secretion through its action to increase membrane fluidity and recruitment of APP at the cell surface.
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Affiliation(s)
- Xiaoguang Yang
- Department of Biological Engineering, University of Missouri, Columbia, MO 65211, USA
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36
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Alterations of concentrations of calcium and arachidonic acid and agglutinations of microfilaments in host cells during Toxoplasma gondii invasion. Vet Parasitol 2008; 157:21-33. [DOI: 10.1016/j.vetpar.2008.07.007] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2008] [Revised: 07/04/2008] [Accepted: 07/07/2008] [Indexed: 11/19/2022]
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Liu SJ. Inhibition of L-type Ca2+channel current and negative inotropy induced by arachidonic acid in adult rat ventricular myocytes. Am J Physiol Cell Physiol 2007; 293:C1594-604. [PMID: 17804608 DOI: 10.1152/ajpcell.00284.2007] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
We have previously shown an increase in arachidonic acid (AA) release in response to proinflammatory cytokines in adult rat ventricular myocytes (ARVM). AA is known to alter channel activities; however, its effects on cardiac L-type Ca2+channel current ( ICa,L) and excitation-contraction coupling remain unclear. The present study examined effects of AA on ICa,L, using the whole cell patch-clamp technique, and on cell shortening (CS) and the Ca2+transient of ARVM. ICa,Lwas monitored in myocytes held at −70 mV and internally equilibrated and externally perfused with Na+- and K+-free solutions. Exposure to AA caused a voltage-dependent block of ICa,Lconcentration dependently (IC508.5 μM). The AA-induced inhibition of ICa,Lis consistent with its hyperpolarizing shift in the voltage-dependent properties and reduction in maximum slope conductance. In the presence of AA, BSA completely blocked the AA-induced suppression of ICa,Land CS. Intracellular load with AA had no effect on the current density but caused a small depolarizing shift in the ICa,Lactivation curve, suggesting a site-specific action of AA. Moreover, intracellular AA had no effect on the extracellular AA-induced decrease in ICa,L. Pretreatment with indomethacin, an inhibitor of cyclooxygenase, or addition of nordihydroguaiaretic acid, an inhibitor of lipoxygenase, had no effect on AA-induced changes in ICa,L. Furthermore, AA suppressed CS and Ca2+transients of intact ARVM with no significant effect on SR function and myofilament Ca2+sensitivity. Therefore, these results suggest that AA inhibits contractile function of ARVM, primarily due to its direct inhibition of ICa,Lat an extracellular site.
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Affiliation(s)
- Shi J Liu
- Dept. of Pharmaceutical Sciences and Dept. of Pharmacology & Toxicology, Univ. of Arkansas for Medical Sciences, 4301 West Markham St. MS 522-3, Little Rock, AR 72205, USA.
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Jensen LDE, Hansen AJ, Lundbaek JA. Regulation of endothelial cell migration by amphiphiles—are changes in cell membrane physical properties involved? Angiogenesis 2007; 10:13-22. [PMID: 17265099 DOI: 10.1007/s10456-006-9060-y] [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: 04/08/2006] [Accepted: 12/11/2006] [Indexed: 12/24/2022]
Abstract
Endothelial cell (EC) migration is an integral part of angiogenesis and a prerequisite for malignant tumor growth. Recent studies suggest that amphiphilic compounds can regulate migration of bovine aortic ECs by altering the physical properties of the cell membrane lipid bilayers. A number of structurally different amphiphiles thus regulate the migration in quantitative correlation with their effects on the plasma membrane microviscosity. Many amphiphiles that affect EC migration and angiogenesis alter the physical properties of lipid bilayers, suggesting that such a regulatory mechanism may be of general importance. To investigate this notion, we studied the effects of lysophospholipids that inhibit migration of bovine aortic ECs and decrease cell membrane microviscosity, and of other amphiphiles that decrease membrane microviscosity (Triton X-100, octyl-beta-glucoside, arachidonic acid, docosahexaenoic acid, ETYA, capsaicin) on the migration of porcine aortic ECs. We further studied whether the enzyme secretory phospholipase A(2) (sPLA(2)) would affect migration in accordance with the changes in membrane microviscosity induced by its hydrolysis products lysophospholipids and polyunsaturated fatty acids. Arachidonic acid, at low concentrations, promoted cell migration by a mechanism involving metabolic products of this compound. Apart from this effect, all the amphiphiles, as well as sPLA(2), inhibited cell migration. A semi-quantitative analysis found a similar correlation between the effects on migration and on lipid bilayer stiffness measured using gramicidin channels as molecular force transducers. These results suggest that changes in cell membrane physical properties may generally contribute to the effects of amphiphiles on EC migration.
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Affiliation(s)
- Lasse D E Jensen
- Department of Cancer and Immunobiology, Novo Nordisk A/S, Novo Nordisk Park, Måløv, Denmark
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Berrougui H, Isabelle M, Cherki M, Khalil A. Marrubium vulgare extract inhibits human-LDL oxidation and enhances HDL-mediated cholesterol efflux in THP-1 macrophage. Life Sci 2006; 80:105-12. [PMID: 17045616 DOI: 10.1016/j.lfs.2006.08.040] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2006] [Revised: 08/18/2006] [Accepted: 08/21/2006] [Indexed: 12/20/2022]
Abstract
The objective of the present study was to elucidate the beneficial properties of aqueous extracts of Marrubium vulgare (AEM) towards cardiovascular disease by protecting human-LDL against lipid peroxidation and promoting HDL-mediated cholesterol efflux. Human-LDL were oxidised by incubation with CuSO(4) in the presence of increased concentrations of AEM (0-100 microg/ml). LDL lipid peroxidation was evaluated by conjugated diene formation, vitamin E disappearance as well as LDL-electrophoretic mobility. HDL-mediated cholesterol efflux assay was carried out in human THP-1 macrophages. Incubation of LDL with AEM significantly prolonged the lag phase (P=0.014), lowered the progression rate of lipid peroxidation (P=0.004), reduced the disappearance of vitamin E and the electrophoretic mobility in a dose-dependent manner. Also, incubation of HDL with AEM significantly increased HDL-mediated cholesterol efflux from THP-1 macrophages implicating an independent ATP binding cassette A1 (ABCA1) pathways. Our findings suggest that M. vulgare provides a source of natural antioxidants, which inhibit LDL oxidation and enhance reverse cholesterol transport and thus can prevent cardiovascular diseases development. These antioxidant properties increase the anti-atherogenic potential of HDL.
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Berrougui H, Cloutier M, Isabelle M, Khalil A. Phenolic-extract from argan oil (Argania spinosa L.) inhibits human low-density lipoprotein (LDL) oxidation and enhances cholesterol efflux from human THP-1 macrophages. Atherosclerosis 2006; 184:389-96. [PMID: 16019008 DOI: 10.1016/j.atherosclerosis.2005.05.018] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/16/2004] [Revised: 05/12/2005] [Accepted: 05/17/2005] [Indexed: 12/27/2022]
Abstract
Argan oil is rich in unsaturated fatty acids, tocopherol and phenolic compounds. These protective molecules make further study of its cardiovascular diseases (CVDs) action interesting. Furthermore, no previous study has explored the antioxidant activity of argan oil in comparison with olive oil. The present study was conducted to evaluate the beneficial properties of Virgin argan oil phenolic extracts (VAO-PE) towards CVD by: (A) protecting human (low-density lipoprotein, LDL) against lipid peroxidation and (B) promoting high-density lipoprotein (HDL)-mediated cholesterol efflux. Human LDLs were oxidized by incubation with CuSO(4) in the presence of different concentrations of VAO-PE (0-320mug/ml). LDL lipid peroxidation was evaluated by conjugated diene and MDA formation as well as Vitamin E disappearance. Incubation of LDL with VAO-PE significantly prolonged the lag-phase and lowered the progression rate of lipid peroxidation (P<0.01) and reduced the disappearance of Vitamin E in a concentration-dependent manner. Incubation of HDL with VAO-PE significantly increased the fluidity of the HDL phospholipidic bilayer (P=0.0004) and HDL-mediated cholesterol efflux from THP-1 macrophages. These results suggest that Virgin argan oil provides a source of dietary phenolic antioxidants, which prevent cardiovascular diseases by inhibiting LDL-oxidation and enhancing reverse cholesterol transport. These properties increase the anti-atherogenic potential of HDL.
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Affiliation(s)
- Hicham Berrougui
- Research Centre on Aging, Sherbrooke Geriatric University Institute, University of Sherbrooke, Sherbrooke, Que., Canada J1H 4C4
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41
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Luo D, Sun H, Lan X, Xiao R, Han Q. Direct coupling between arachidonic acid-induced Ca2+ release and Ca2+ entry in HEK293 cells. Prostaglandins Other Lipid Mediat 2005; 75:141-51. [PMID: 15789621 DOI: 10.1016/j.prostaglandins.2004.11.004] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Arachidonic acid (AA) modulates intracellular Ca2+ signaling via Ca2+ release or/and Ca2+ entry. However, the mechanism underlies either process is unknown; nor is it clear as to whether the two processes are mechanistically linked. By using Fura2/AM, we found that AA induced mobilization of internal Ca2+ store and an increment in Ca2+, Mn2+ and Ba2+ influx in HEK293 cells. The AA-mediated Ca2+ signaling was not due to AA metabolites, and insensitive to capacitative Ca2+ entry inhibitors. Interestingly, isotetrandrine and Gd3+ inhibited both AA-induced Ca2+ release and Ca2+ entry in a concentration-dependent manner without affecting Ca2+ discharge caused by carbachol, caffeine, or thapsigargin. Additionally, similar pattern of inhibition was observed with tetracaine treatment. More importantly, the three compounds exhibited almost equal potent inhibition of AA-initiated Ca2+ release as well as Ca2+ influx. Therefore, this study, for the first time, provides evidence for a direct coupling between AA-mediated Ca2+ release and Ca2+ entry.
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Affiliation(s)
- Dali Luo
- Institute of Cardiovascular Science at Health Science Center, Peking University, Beijing 100083, PR China.
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43
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Suarez JI, Shannon L, Zaidat OO, Suri MF, Singh G, Lynch G, Selman WR. Effect of human albumin administration on clinical outcome and hospital cost in patients with subarachnoid hemorrhage. J Neurosurg 2004; 100:585-90. [PMID: 15070109 DOI: 10.3171/jns.2004.100.4.0585] [Citation(s) in RCA: 53] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
OBJECT Human albumin is used to induce hypervolemia (central venous pressure [CVP] > 8 mm Hg) after subarachnoid hemorrhage (SAH). Unfortunately, human albumin may increase the mortality rate in critically ill patients; because of this, its use became restricted in the authors' hospital in May 1999. The goal of this study was to determine the effect of human albumin on outcome and cost in patients with SAH before and after this restriction was put into place. METHODS All patients with aneurysmal SAH who were admitted to the authors' institution between May 1998 and May 2000 were studied. Basic demographic information, dosage of human albumin given, length of stay, and the incidence of in-hospital deaths and complications were collected. The authors obtained Glasgow Outcome Scale (GOS) scores at 3 months after SAH (good outcome, GOS > or = 4). Data were analyzed using t-test and chi-square analysis. Logistic regression was used to identify independent associations between use of human albumin and outcome. The authors studied 140 patients: 63 who were admitted between May 1998 and May 1999 (Group 1) and 77 treated between June 1999 and May 2000 (Group 2). Two subgroups of patients were further analyzed. Group 1 patients who received human albumin (albumin subgroup, 37 patients) and Group 2 patients who would have received albumin under the old protocol (that is, those who failed to achieve CVP > 8 mm Hg after normal saline administration; nonalbumin subgroup, 47 patients). Patients in the nonalbumin subgroup were more likely to be male (38% compared with 16%), to experience hypertension (55% compared with 30%), to suffer from hypomagnesemia (49% compared with 5.4%), and to have hydrocephalus (47% compared with 27%). There was a trend for these patients to have more vasospasm (28% compared with 19%, p = 0.2). Patients in the albumin subgroup were more likely to have a good outcome at 3 months. CONCLUSIONS Administration of human albumin after SAH may improve clinical outcome and reduce hospital cost.
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Affiliation(s)
- Jose I Suarez
- Neurosciences Critical Care, University Hospitals of Cleveland, Case Western Reserve University, Cleveland, Ohio 44106, USA.
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Larbi A, Douziech N, Khalil A, Dupuis G, Gheraïri S, Guérard KP, Fülöp T. Effects of methyl-β-cyclodextrin on T lymphocytes lipid rafts with aging. Exp Gerontol 2004; 39:551-8. [PMID: 15050290 DOI: 10.1016/j.exger.2003.10.031] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2003] [Revised: 09/07/2003] [Accepted: 10/09/2003] [Indexed: 02/06/2023]
Abstract
Aging is associated with a decline in immune functions. Among them, T-cell activation is altered at several points of the signaling cascade following TCR engagement. Recent findings suggest that lipid rafts act as a platform in the initiation of T-cell activation. We have previously demonstrated that cholesterol content in T-cells increased with aging, especially in lipid rafts. Cholesterol, which is a major component of lipid rafts, serves to stabilize their structure. We hypothesized that restoring T-cell cholesterol content and membrane fluidity would restore, at least in part, T-cell function via lipid rafts. We measured the lipid rafts coalescence, the p56(Lck) and linker of activated T-cell (LAT) signaling molecules recruitment and activation, the cholesterol content and fluidity in T-cell membrane after different methyl-beta-cyclodextrin (MBCD) treatments. Our results show that high concentration of MBCD (10 mM) completely disorganized the lipid rafts in T-cell membranes of young and elderly donors, however, T-cells from elderly donors were less sensitive than T-cells of young donors to low concentration of MBCD (0.5 mM). p56(Lck) and LAT recruitment and activation were affected in T-cells of both aged groups. MBCD treatment did not affect the cholesterol content and fluidity of T-cell membranes of young donors, while the cholesterol content was decreased and fluidity increased in lipid rafts of elderly donors. These results suggested that cholesterol extraction by MBCD increased the fluidity and disrupted lipid rafts organization. The increase in cholesterol content in lipid rafts with aging and its decrease by biochemical extraction were able to affect early signaling molecules activation. Restoring cholesterol content and fluidity may have beneficial effects, however, MBCD disorganized the membrane and this might not completely restore the T-cell activation via lipid rafts with aging. Altogether these results suggest that defects in cholesterol cellular homeostasis may be part of T-cell immunosenescence via lipid rafts dysfunction.
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Affiliation(s)
- Anis Larbi
- Research Center on Aging, Sherbrooke Geriatric University Institute, University of Sherbrooke, Sherbrooke, Que., Canada J1H 5N4
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Larbi A, Douziech N, Dupuis G, Khalil A, Pelletier H, Guerard KP, Fülöp T. Age-associated alterations in the recruitment of signal-transduction proteins to lipid rafts in human T lymphocytes. J Leukoc Biol 2003; 75:373-81. [PMID: 14657209 DOI: 10.1189/jlb.0703319] [Citation(s) in RCA: 111] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Aging is associated with a decline in T cell activation and proliferation, but the underlying mechanisms are not fully understood. Recent findings suggest that lipid rafts act as a platform in the initiation of T cell activation by selectively recruiting signaling proteins associated with formation of the initial complex of signal transduction. We tested the hypothesis that lipid raft properties are altered in T lymphocytes from elderly, healthy individuals in comparison with young subjects. Results showed that the cholesterol content of lipid rafts derived from these cells was consistently higher in the case of elderly donors and that membrane fluidity was decreased. In addition, lipid rafts coalescence to the site of T cell receptor engagement was impaired in T cells from elderly donors. The recruitment of p56(lck), linker of activated T cells, and their tyrosine-phosphorylated forms to lipid rafts was decreased in activated T cells from aged individuals. CD45 was not recruited to the lipid raft fractions in either group of subjects. Our data suggest that some properties of lipid rafts are altered in aging, and this finding may be part of the causes for the decline in T cell functions that are observed in elderly individuals.
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Affiliation(s)
- Anis Larbi
- Research Center on Aging, Geriatric Institute, Clinical Research Center, University of Sherbrooke, 1036 Belvedere St. South, Sherbrooke, QC, Canada J1H 4C4
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Sen S, Jalan R, Williams R. Liver failure: basis of benefit of therapy with the molecular adsorbents recirculating system. Int J Biochem Cell Biol 2003; 35:1306-11. [PMID: 12798344 DOI: 10.1016/s1357-2725(03)00045-1] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Accumulation of albumin-bound toxins is known to occur in liver failure, and to variable extents is responsible for the associated end-organ dysfunctions (kidney, circulation, brain). The toxin-binding and scavenging functions of albumin are exploited in albumin dialysis for removal of these toxins. The extracorporeal liver support device known as molecular adsorbents recirculating system (MARS) is based on dialysis across an albumin-impregnated membrane, using 20% albumin as dialysate. Charcoal and anion exchange resin columns in the circuit help cleanse and regenerate the dialysate. Clinical studies over the last few years have demonstrated proven reduction in hyperbilirubinaemia, along with an improvement in encephalopathy, systemic haemodynamics and renal function in liver failure patients, as well as apparent improvement in survival. The results of larger controlled clinical trials, as well as studies investigating the pathophysiological basis of its effect, are awaited.
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Affiliation(s)
- Sambit Sen
- Institute of Hepatology, University College London, 69-75 Chenies Mews, London, WC1E 6HX, UK
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Fiorini S, Ferretti ME, Biondi C, Pavan B, Lunghi L, Paganetto G, Abelli L. 17Beta-eEstradiol stimulates arachidonate release from human amnion-like WISH cells through a rapid mechanism involving a membrane receptor. Endocrinology 2003; 144:3359-67. [PMID: 12865314 DOI: 10.1210/en.2002-221106] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
17beta-Estradiol (17beta-E(2)) greatly and dose-dependently stimulates [(3)H]arachidonic acid (AA) release from the human amnion-like Wistar Institute Susan Hayflick (WISH) cells. This action is abolished by the phospholipase A(2) inhibitor AACOCF(3), significantly reduced by the estrogen receptor (ER) antagonist ICI 182,780, and uninfluenced by cycloheximide. The estradiol-BSA conjugate E(2)coBSA, which binds putative membrane ERs and is unable to enter the cell, also highly stimulates [(3)H]AA release from WISH cells, although to a lesser extent compared with 17beta-E(2). The fluorescent conjugate E(2)coBSA-FITC specifically binds to the surface of a subset of intact WISH cells, and labeling intensity appears dose and time dependent. Cell permeabilization results in a dense intracellular staining, mainly in the peripheral cytoplasm. H-150, an antibody against the N terminus of human ERbeta, also labels the plasma membrane of intact WISH cells and the cytoplasm of permeabilized cells. Almost no labeling is observed using ER-21, an antibody against the N terminus of human ERalpha. RT-PCR evidences the presence of mRNA for ERbeta, not for ERalpha. Our data suggest that 17beta-E(2) stimulates [(3)H]AA release from WISH cells through an apparently nongenomic pathway and interaction with membrane binding sites. These last are, at least in part, similar if not identical to ERbeta.
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Affiliation(s)
- Sara Fiorini
- Department of Biology, University of Ferrara, 44100-I Ferrara, Italy
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Alvarez-Guerra M, Hannaert P, Hider H, Chiavaroli C, Garay RP. Vascular permeabilization by intravenous arachidonate in the rat peritoneal cavity: antagonism by antioxidants. Eur J Pharmacol 2003; 466:199-205. [PMID: 12679157 DOI: 10.1016/s0014-2999(03)01544-9] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Arachidonic acid was investigated for its vascular permeabilizing potential in the rat peritoneal cavity and for its mechanism of action. The antagonistic potential of antioxidants (vitamin E, vitamin C and troxerutin) was also evaluated. Vascular permeability was equated to the rate of extravasation of Evans blue dye from plasma into the peritoneal cavity. Baseline permeability was linear up to 2 h, with a rate constant (k) of 0.0031+/-0.0007 h(-1). Intravenous arachidonate (from 30 microg/kg to 3 mg/kg) induced an immediate, dose-related and significant increase in permeability (ranging from 80% to 150%), which was comparable to the effect induced by similar doses of serotonin. Aspirin (10 mg/kg) reduced the arachidonate-induced permeability by 75%, but interestingly neither the stable thromboxane A(2) receptor agonist U46619 (prostaglandin H(2) endoperoxide epoxymethane) nor prostacyclin was able to increase peritoneal vascular permeability. In contrast, the permeabilizing action of arachidonic acid was very sensitive to antioxidant agents. Thus, vitamin C and the flavonoid compound troxerutin (100 mg/kg) fully abolished arachidonate-induced permeability, whereas vitamin E had only a partial effect (40-100% inhibition). In conclusion, intravenous administration of arachidonic acid strongly enhanced peritoneal vascular permeability in the rat, apparently via free radical generation. This rat peritoneal model can be used to evaluate the in vivo antinflammatory potential of antioxidant drugs.
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Affiliation(s)
- Miriam Alvarez-Guerra
- INSERM U400, Faculté de Médecine, 8 rue du Général Sarrail, 94010 Cédex, Créteil, France
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Evans TW. Review article: albumin as a drug--biological effects of albumin unrelated to oncotic pressure. Aliment Pharmacol Ther 2002; 16 Suppl 5:6-11. [PMID: 12423448 DOI: 10.1046/j.1365-2036.16.s5.2.x] [Citation(s) in RCA: 242] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Albumin is the main determinant of plasma oncotic pressure and it plays a pivotal role in modulating the distribution of fluids between compartments. Moreover, it has many other biological properties which may be important not only for its physiological actions but also for its therapeutic effects. Among the non-oncotic properties are its capacity of molecule transportation and free radical scavenging, its ability to modulate capillar permeability, neutrophil adhesion and activation and its haemostatic effects. The following article reviews these biological effects as well as its structure, synthesis, catabolism and distribution.
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Affiliation(s)
- T W Evans
- Department of Intensive Care Medicine, Imperial College of Science, Technology & Medicine, Clinical Director of ICU, Royal Brompton Hospital, London, UK.
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Sergeeva M, Strokin M, Wang H, Ubl JJ, Reiser G. Arachidonic acid and docosahexaenoic acid suppress thrombin-evoked Ca2+ response in rat astrocytes by endogenous arachidonic acid liberation. J Neurochem 2002; 82:1252-61. [PMID: 12358772 DOI: 10.1046/j.1471-4159.2002.01052.x] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Arachidonic (AA) and docosahexaenoic acid (DHA) are the major polyunsaturated fatty acids (PUFAs) in the brain. However, their influence on intracellular Ca2+ signalling is still widely unknown. In astrocytes, the amplitude of thrombin- induced Ca2+ response was time-dependently diminished by AA and DHA, or by the AA tetraynoic analogue ETYA, but not by eicosapentaenoic acid (EPA). Thrombin-elicited Ca2+ response was reduced (20-30%) by 1-min exposure to AA or DHA. Additionally, 1-min application of AA or DHA together with thrombin in Ca2+-free medium blocked Ca2+ influx, which followed after readdition of extracellular Ca2+. EPA and ETYA, however, were ineffective. Long-term treatment of astrocytes with AA and DHA, but not EPA reduced the amplitude of the thrombin-induced Ca2+ response by up to 80%. AA and DHA caused a comparable decrease in intracellular Ca2+ store content. Only DHA and AA, but not EPA or ETYA, caused liberation of endogenous AA by cytosolic phospholipase A2 (cPLA2). Therefore, we reasoned that the suppression of Ca2+ response to thrombin by AA and DHA could be due to release of endogenous AA. Possible participation of AA metabolites, however, was excluded by the finding that specific inhibitors of the different oxidative metabolic pathways of AA were not able to abrogate the inhibitory AA effect. In addition, thrombin evoked AA release via activation of cPLA2. From our data we propose a novel model of positive/negative-feed-back in which agonist-induced release of AA from membrane phospholipids promotes further AA release and then suppresses agonist-induced Ca2+ responses.
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Affiliation(s)
- Marina Sergeeva
- Institut für Neurobiochemie, Medizinische Fakultät der Otto-von-Guericke-Universität Magdeburg, Germany
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