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Khan NS, Song CY, Thirunavukkarasu S, Fang XR, Bonventre JV, Malik KU. Cytosolic Phospholipase A2α Is Essential for Renal Dysfunction and End-Organ Damage Associated With Angiotensin II-Induced Hypertension. Am J Hypertens 2016; 29:258-65. [PMID: 26045535 DOI: 10.1093/ajh/hpv083] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2015] [Accepted: 05/13/2015] [Indexed: 01/11/2023] Open
Abstract
BACKGROUND The kidney plays an important role in regulating blood pressure (BP). cPLA2α in the kidney is activated by various agents including angiotensin II (Ang II) and selectively releases arachidonic acid (AA) from tissue lipids, generating pro- and antihypertensive eicosanoids. Since activation of cPLA2α is the rate-limiting step in AA release, this study was conducted to determine its contribution to renal dysfunction and end-organ damage associated with Ang II-induced hypertension. METHODS cPLA2α(+/+) and cPLA2α(-/-) mice were infused with Ang II (700 ng/ kg/min) or its vehicle for 13 days. Mice were placed in metabolic cages to monitor their food and water intake, and urine was collected and its volume was measured. Doppler imaging was performed to assess renal hemodynamics. On the 13th day of Ang II infusion, mice were sacrificed and their tissues and blood collected for further analysis. RESULTS Ang II increased renal vascular resistance, water intake, and urine output and Na(+) excretion, decreased urine osmolality, and produced proteinuria in cPLA2α(+/+) mice. Ang II also caused accumulation of F4/80(+) macrophages and CD3(+) T cells and renal fibrosis, and increased oxidative stress in the kidneys of cPLA2α(+/+) mice. All these effects of Ang II were minimized in cPLA2α(-/-) mice. CONCLUSION cPLA2α contributes to renal dysfunction, inflammation, and end-organ damage, most likely via the action of pro-hypertensive eicosanoids and increased oxidative stress associated with Ang II-induced hypertension. Thus, cPLA2α could serve as a potential therapeutic target for treating renal dysfunction and end-organ damage in hypertension.
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Affiliation(s)
- Nayaab S Khan
- Department of Pharmacology, College of Medicine, The University of Tennessee Health Science Center, Memphis, Tennessee, USA
| | - Chi Young Song
- Department of Pharmacology, College of Medicine, The University of Tennessee Health Science Center, Memphis, Tennessee, USA
| | - Shyamala Thirunavukkarasu
- Department of Pharmacology, College of Medicine, The University of Tennessee Health Science Center, Memphis, Tennessee, USA
| | - Xiao R Fang
- Department of Pharmacology, College of Medicine, The University of Tennessee Health Science Center, Memphis, Tennessee, USA
| | - Joseph V Bonventre
- Renal Division, Department of Medicine, Brigham and Women's Hospital Boston, Harvard Medical School, Harvard Institute of Medicine, Boston, Massachusetts, USA
| | - Kafait U Malik
- Department of Pharmacology, College of Medicine, The University of Tennessee Health Science Center, Memphis, Tennessee, USA;
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Ntranos A, Hall O, Robinson DP, Grishkan IV, Schott JT, Tosi DM, Klein SL, Calabresi PA, Gocke AR. FTY720 impairs CD8 T-cell function independently of the sphingosine-1-phosphate pathway. J Neuroimmunol 2014; 270:13-21. [PMID: 24680062 DOI: 10.1016/j.jneuroim.2014.03.007] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2013] [Revised: 01/24/2014] [Accepted: 03/03/2014] [Indexed: 12/29/2022]
Abstract
Fingolimod (FTY720) is a multiple sclerosis (MS) therapeutic that upon phosphorylation causes the internalization of sphingosine-1-phosphate receptors (S1PR) and traps CCR7+ T-cells in lymph nodes but relatively spares CCR7-effector T-cells. Nonetheless, FTY720-treated patients are more susceptible to viral infections, indicating a CD8 T-cell defect. Thus, the effects of FTY720 on CD8 T-cells were investigated. To this end, we utilized experimental autoimmune encephalomyelitis (EAE) and a murine influenza model. CD8 T-cell trafficking, IFNγ and Granzyme B (GrB) production were assessed by flow cytometry. CD8 T-cell cytotoxic function was assessed in vitro by an LDH release assay. FTY720 not only ameliorated EAE by sequestering T-cells, but also reduced IFNγ and Granzyme B (GrB) in splenic CD8 T-cells. Murine influenza infection was exacerbated and mortality was increased, as FTY720 inhibited CD8 T-cell GrB production and lung infiltration. Remarkably, only the unphosphorylated compound was able to reduce IFNγ and GrB levels in CD8 T-cells and inhibits their cytotoxic function in vitro. The phosphorylated moiety had no effect in vitro, indicating that CD8 T-cell suppression by FTY720 is independent of S1PR modulation. The addition of arachidonic acid rescued CD8 T-cell function, suggesting that this effect may be mediated via inhibition of cytosolic phospholipase A2. Herein, we demonstrate that FTY720 suppresses CD8 T-cells independently of its trafficking effects and S1PR modulation. This provides a novel explanation not only for the increased rate of viral infections in FTY720-treated patients, but also for its efficacy in MS, as CD8 T-cells have emerged as crucial mediators of MS pathogenesis.
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Affiliation(s)
- Achilles Ntranos
- Department of Neurology, Johns Hopkins University School of Medicine, 600 N. Wolfe St., Baltimore, MD 21287, USA
| | - Olivia Hall
- W. Harry Feinstone Department of Molecular Microbiology and Immunology, The Johns Hopkins Bloomberg School of Public Health, 615 N. Wolfe St., Baltimore, MD 21205, USA
| | - Dionne P Robinson
- W. Harry Feinstone Department of Molecular Microbiology and Immunology, The Johns Hopkins Bloomberg School of Public Health, 615 N. Wolfe St., Baltimore, MD 21205, USA
| | - Inna V Grishkan
- Department of Neurology, Johns Hopkins University School of Medicine, 600 N. Wolfe St., Baltimore, MD 21287, USA
| | - Jason T Schott
- Department of Neurology, Johns Hopkins University School of Medicine, 600 N. Wolfe St., Baltimore, MD 21287, USA
| | - Dominique M Tosi
- Department of Neurology, Johns Hopkins University School of Medicine, 600 N. Wolfe St., Baltimore, MD 21287, USA
| | - Sabra L Klein
- W. Harry Feinstone Department of Molecular Microbiology and Immunology, The Johns Hopkins Bloomberg School of Public Health, 615 N. Wolfe St., Baltimore, MD 21205, USA
| | - Peter A Calabresi
- Department of Neurology, Johns Hopkins University School of Medicine, 600 N. Wolfe St., Baltimore, MD 21287, USA.
| | - Anne R Gocke
- Department of Neurology, Johns Hopkins University School of Medicine, 600 N. Wolfe St., Baltimore, MD 21287, USA.
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Nicolaou A, Mauro C, Urquhart P, Marelli-Berg F. Polyunsaturated Fatty Acid-derived lipid mediators and T cell function. Front Immunol 2014; 5:75. [PMID: 24611066 PMCID: PMC3933826 DOI: 10.3389/fimmu.2014.00075] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2013] [Accepted: 02/11/2014] [Indexed: 01/10/2023] Open
Abstract
Fatty acids are involved in T cell biology both as nutrients important for energy production as well as signaling molecules. In particular, polyunsaturated fatty acids are known to exhibit a range of immunomodulatory properties that progress through T cell mediated events, although the molecular mechanisms of these actions have not yet been fully elucidated. Some of these immune activities are linked to polyunsaturated fatty acid-induced alteration of the composition of cellular membranes and the consequent changes in signaling pathways linked to membrane raft-associated proteins. However, significant aspects of the polyunsaturated fatty acid bioactivities are mediated through their transformation to specific lipid mediators, products of cyclooxygenase, lipoxygenase, or cytochrome P450 enzymatic reactions. Resulting bioactive metabolites including prostaglandins, leukotrienes, and endocannabinoids are produced by and/or act upon T leukocytes through cell surface receptors and have been shown to alter T cell activation and differentiation, proliferation, cytokine production, motility, and homing events. Detailed appreciation of the mode of action of these lipids presents opportunities for the design and development of therapeutic strategies aimed at regulating T cell function.
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Affiliation(s)
- Anna Nicolaou
- Manchester Pharmacy School, Faculty of Medical and Human Sciences, The University of Manchester , Manchester , UK
| | - Claudio Mauro
- Centre for Biochemical Pharmacology, William Harvey Research Institute, Queen Mary University of London , London , UK
| | - Paula Urquhart
- Manchester Pharmacy School, Faculty of Medical and Human Sciences, The University of Manchester , Manchester , UK
| | - Federica Marelli-Berg
- Centre for Biochemical Pharmacology, William Harvey Research Institute, Queen Mary University of London , London , UK
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Lone AM, Taskén K. Proinflammatory and immunoregulatory roles of eicosanoids in T cells. Front Immunol 2013; 4:130. [PMID: 23760108 PMCID: PMC3671288 DOI: 10.3389/fimmu.2013.00130] [Citation(s) in RCA: 87] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2013] [Accepted: 05/17/2013] [Indexed: 01/08/2023] Open
Abstract
Eicosanoids are inflammatory mediators primarily generated by hydrolysis of membrane phospholipids by phospholipase A2 to ω-3 and ω-6 C20 fatty acids that next are converted to leukotrienes (LTs), prostaglandins (PGs), prostacyclins (PCs), and thromboxanes (TXAs). The rate-limiting and tightly regulated lipoxygenases control synthesis of LTs while the equally well-controlled cyclooxygenases 1 and 2 generate prostanoids, including PGs, PCs, and TXAs. While many of the classical signs of inflammation such as redness, swelling, pain, and heat are caused by eicosanoid species with vasoactive, pyretic, and pain-inducing effects locally, some eicosanoids also regulate T cell functions. Here, we will review eicosanoid production in T cell subsets and the inflammatory and immunoregulatory functions of LTs, PGs, PCs, and TXAs in T cells.
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Affiliation(s)
- Anna Mari Lone
- Centre for Molecular Medicine Norway, Nordic EMBL Partnership, University of Oslo and Oslo University Hospital , Oslo , Norway ; Biotechnology Centre, University of Oslo , Oslo , Norway ; K.G. Jebsen Inflammation Research Centre, University of Oslo , Oslo , Norway
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Belibasakis GN, Reddi D, Bostanci N. Porphyromonas gingivalis Induces RANKL in T-cells. Inflammation 2010; 34:133-8. [DOI: 10.1007/s10753-010-9216-1] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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Tang F, Chen Z, Ciszewski C, Setty M, Solus J, Tretiakova M, Ebert E, Han J, Lin A, Guandalini S, Groh V, Spies T, Green P, Jabri B. Cytosolic PLA2 is required for CTL-mediated immunopathology of celiac disease via NKG2D and IL-15. ACTA ACUST UNITED AC 2009; 206:707-19. [PMID: 19237603 PMCID: PMC2699120 DOI: 10.1084/jem.20071887] [Citation(s) in RCA: 73] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
IL-15 and NKG2D promote autoimmunity and celiac disease by arming cytotoxic T lymphocytes (CTLs) to cause tissue destruction. However, the downstream signaling events underlying these functional properties remain unclear. Here, we identify cytosolic phospholipase A2 (cPLA2) as a central molecule in NKG2D-mediated cytolysis in CTLs. Furthermore, we report that NKG2D induces, upon recognition of MIC+ target cells, the release of arachidonic acid (AA) by CTLs to promote tissue inflammation in association with target killing. Interestingly, IL-15, which licenses NKG2D-mediated lymphokine killer activity in CTLs, cooperates with NKG2D to induce cPLA2 activation and AA release. Finally, cPLA2 activation in intraepithelial CTLs of celiac patients provides an in vivo pathophysiological dimension to cPLA2 activation in CTLs. These results reveal an unrecognized link between NKG2D and tissue inflammation, which may underlie the emerging role of NKG2D in various immunopathological conditions and define new therapeutic targets.
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Affiliation(s)
- Fangming Tang
- Department of Pathology, University of Chicago, Chicago, IL 60637, USA
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Harizi H, Corcuff JB, Gualde N. Arachidonic-acid-derived eicosanoids: roles in biology and immunopathology. Trends Mol Med 2008; 14:461-9. [PMID: 18774339 DOI: 10.1016/j.molmed.2008.08.005] [Citation(s) in RCA: 409] [Impact Index Per Article: 25.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2008] [Revised: 08/01/2008] [Accepted: 08/01/2008] [Indexed: 12/12/2022]
Abstract
Arachidonic acid (AA)-derived eicosanoids belong to a complex family of lipid mediators that regulate a wide variety of physiological responses and pathological processes. They are produced by various cell types through distinct enzymatic pathways and act on target cells via specific G-protein-coupled receptors. Although originally recognized for their capacity to elicit biological responses such as vascular homeostasis, protection of the gastric mucosa and platelet aggregation, eicosanoids are now understood to regulate immunopathological processes ranging from inflammatory responses to chronic tissue remodelling, cancer, asthma, rheumatoid arthritis and autoimmune disorders. Here, we review the major properties of eicosanoids and their expanding roles in biology and medicine.
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Affiliation(s)
- Hedi Harizi
- Centre National de la Recherche Scientifique, Unité Mixte de Recherche 5540, Immunomodulation par les Médiateurs de l'Inflammation, University of Bordeaux, 33076, France.
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