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Scott SA, Mathews TP, Ivanova PT, Lindsley CW, Brown HA. Chemical modulation of glycerolipid signaling and metabolic pathways. Biochim Biophys Acta Mol Cell Biol Lipids 2014; 1841:1060-84. [PMID: 24440821 DOI: 10.1016/j.bbalip.2014.01.009] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2013] [Revised: 01/06/2014] [Accepted: 01/07/2014] [Indexed: 01/04/2023]
Abstract
Thirty years ago, glycerolipids captured the attention of biochemical researchers as novel cellular signaling entities. We now recognize that these biomolecules occupy signaling nodes critical to a number of physiological and pathological processes. Thus, glycerolipid-metabolizing enzymes present attractive targets for new therapies. A number of fields-ranging from neuroscience and cancer to diabetes and obesity-have elucidated the signaling properties of glycerolipids. The biochemical literature teems with newly emerging small molecule inhibitors capable of manipulating glycerolipid metabolism and signaling. This ever-expanding pool of chemical modulators appears daunting to those interested in exploiting glycerolipid-signaling pathways in their model system of choice. This review distills the current body of literature surrounding glycerolipid metabolism into a more approachable format, facilitating the application of small molecule inhibitors to novel systems. This article is part of a Special Issue entitled Tools to study lipid functions.
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Affiliation(s)
- Sarah A Scott
- Department of Pharmacology, Vanderbilt University Medical Center, Nashville, TN 37232, USA
| | - Thomas P Mathews
- Department of Pharmacology, Vanderbilt University Medical Center, Nashville, TN 37232, USA; Vanderbilt Center for Neuroscience Drug Discovery, Vanderbilt University Medical Center, Nashville, TN 37232, USA
| | - Pavlina T Ivanova
- Department of Pharmacology, Vanderbilt University Medical Center, Nashville, TN 37232, USA
| | - Craig W Lindsley
- Department of Pharmacology, Vanderbilt University Medical Center, Nashville, TN 37232, USA; Vanderbilt Center for Neuroscience Drug Discovery, Vanderbilt University Medical Center, Nashville, TN 37232, USA; Department of Chemistry, Vanderbilt University, Nashville, TN 37235, USA; Vanderbilt Institute of Chemical Biology, Vanderbilt University, Nashville, TN 37235, USA
| | - H Alex Brown
- Department of Pharmacology, Vanderbilt University Medical Center, Nashville, TN 37232, USA; Department of Biochemistry, Vanderbilt University Medical Center, Nashville, TN 37232, USA; Vanderbilt Institute of Chemical Biology, Vanderbilt University, Nashville, TN 37235, USA.
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52
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Kohn BL, Rovis T. Cobaltate anion couples terminal dienes with trifluoroacetic anhydride: a direct fluoroacylation of 1,3-dienes. Chem Sci 2014. [DOI: 10.1039/c4sc00743c] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Perfluoroketones are useful products and intermediates in medicinal and materials chemistry.
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Affiliation(s)
- Benjamin L. Kohn
- Department of Chemistry
- Colorado State University
- Fort Collins, USA
| | - Tomislav Rovis
- Department of Chemistry
- Colorado State University
- Fort Collins, USA
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53
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Gil-de-Gómez L, Astudillo AM, Guijas C, Magrioti V, Kokotos G, Balboa MA, Balsinde J. Cytosolic group IVA and calcium-independent group VIA phospholipase A2s act on distinct phospholipid pools in zymosan-stimulated mouse peritoneal macrophages. THE JOURNAL OF IMMUNOLOGY 2013; 192:752-62. [PMID: 24337743 DOI: 10.4049/jimmunol.1302267] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
Phospholipase A2s generate lipid mediators that constitute an important component of the integrated response of macrophages to stimuli of the innate immune response. Because these cells contain multiple phospholipase A2 forms, the challenge is to elucidate the roles that each of these forms plays in regulating normal cellular processes and in disease pathogenesis. A major issue is to precisely determine the phospholipid substrates that these enzymes use for generating lipid mediators. There is compelling evidence that group IVA cytosolic phospholipase A2 (cPLA2α) targets arachidonic acid-containing phospholipids but the role of the other cytosolic enzyme present in macrophages, the Ca(2+)-independent group VIA phospholipase A2 (iPLA2β) has not been clearly defined. We applied mass spectrometry-based lipid profiling to study the substrate specificities of these two enzymes during inflammatory activation of macrophages with zymosan. Using selective inhibitors, we find that, contrary to cPLA2α, iPLA2β spares arachidonate-containing phospholipids and hydrolyzes only those that do not contain arachidonate. Analyses of the lysophospholipids generated during activation reveal that one of the major species produced, palmitoyl-glycerophosphocholine, is generated by iPLA2β, with minimal or no involvement of cPLA2α. The other major species produced, stearoyl-glycerophosphocholine, is generated primarily by cPLA2α. Collectively, these findings suggest that cPLA2α and iPLA2β act on different phospholipids during zymosan stimulation of macrophages and that iPLA2β shows a hitherto unrecognized preference for choline phospholipids containing palmitic acid at the sn-1 position that could be exploited for the design of selective inhibitors of this enzyme with therapeutic potential.
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Affiliation(s)
- Luis Gil-de-Gómez
- Instituto de Biología y Genética Molecular, Consejo Superior de Investigaciones Científicas, Universidad de Valladolid, 47003 Valladolid, Spain
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54
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Limnios D, Kokotos CG. 2,2,2-Trifluoroacetophenone as an organocatalyst for the oxidation of tertiary amines and azines to N-oxides. Chemistry 2013; 20:559-63. [PMID: 24302616 DOI: 10.1002/chem.201303360] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2013] [Indexed: 11/12/2022]
Abstract
A cheap, mild and environmentally friendly oxidation of tertiary amines and azines to the corresponding N-oxides is reported by using polyfluoroalkyl ketones as efficient organocatalysts. 2,2,2-Trifluoroacetophenone was identified as the optimum catalyst for the oxidation of aliphatic tertiary amines and azines. This oxidation is chemoselective and proceeds in high-to-quantitative yields utilizing 10 mol % of the catalyst and H2 O2 as the oxidant.
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Affiliation(s)
- Dimitris Limnios
- Laboratory of Organic Chemistry, Department of Chemistry, University of Athens, Panepistimiopolis 15771, Athens (Greece), Fax: (+30) 2107274761
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55
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Affiliation(s)
- Dimitris Limnios
- Laboratory of Organic Chemistry,
Department of Chemistry, University of Athens, Panepistimiopolis 15771, Athens, Greece
| | - Christoforos G. Kokotos
- Laboratory of Organic Chemistry,
Department of Chemistry, University of Athens, Panepistimiopolis 15771, Athens, Greece
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56
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Ali T, Kokotos G, Magrioti V, Bone RN, Mobley JA, Hancock W, Ramanadham S. Characterization of FKGK18 as inhibitor of group VIA Ca2+-independent phospholipase A2 (iPLA2β): candidate drug for preventing beta-cell apoptosis and diabetes. PLoS One 2013; 8:e71748. [PMID: 23977134 PMCID: PMC3748103 DOI: 10.1371/journal.pone.0071748] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2013] [Accepted: 06/30/2013] [Indexed: 01/27/2023] Open
Abstract
Ongoing studies suggest an important role for iPLA2β in a multitude of biological processes and it has been implicated in neurodegenerative, skeletal and vascular smooth muscle disorders, bone formation, and cardiac arrhythmias. Thus, identifying an iPLA2βinhibitor that can be reliably and safely used in vivo is warranted. Currently, the mechanism-based inhibitor bromoenol lactone (BEL) is the most widely used to discern the role of iPLA2β in biological processes. While BEL is recognized as a more potent inhibitor of iPLA2 than of cPLA2 or sPLA2, leading to its designation as a "specific" inhibitor of iPLA2, it has been shown to also inhibit non-PLA2 enzymes. A potential complication of its use is that while the S and R enantiomers of BEL exhibit preference for cytosol-associated iPLA2β and membrane-associated iPLA2γ, respectively, the selectivity is only 10-fold for both. In addition, BEL is unstable in solution, promotes irreversible inhibition, and may be cytotoxic, making BEL not amenable for in vivo use. Recently, a fluoroketone (FK)-based compound (FKGK18) was described as a potent inhibitor of iPLA2β. Here we characterized its inhibitory profile in beta-cells and find that FKGK18: (a) inhibits iPLA2β with a greater potency (100-fold) than iPLA2γ, (b) inhibition of iPLA2β is reversible, (c) is an ineffective inhibitor of α-chymotrypsin, and (d) inhibits previously described outcomes of iPLA2β activation including (i) glucose-stimulated insulin secretion, (ii) arachidonic acid hydrolysis; as reflected by PGE2 release from human islets, (iii) ER stress-induced neutral sphingomyelinase 2 expression, and (iv) ER stress-induced beta-cell apoptosis. These findings suggest that FKGK18 is similar to BEL in its ability to inhibit iPLA2β. Because, in contrast to BEL, it is reversible and not a non-specific inhibitor of proteases, it is suggested that FKGK18 is more ideal for ex vivo and in vivo assessments of iPLA2β role in biological functions.
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Affiliation(s)
- Tomader Ali
- Department of Cell, Developmental, and Integrative Biology, University of Alabama at Birmingham, Birmingham, Alabama, United States of America
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57
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Bucher D, Hsu YH, Mouchlis VD, Dennis EA, McCammon JA. Insertion of the Ca²⁺-independent phospholipase A₂ into a phospholipid bilayer via coarse-grained and atomistic molecular dynamics simulations. PLoS Comput Biol 2013; 9:e1003156. [PMID: 23935474 PMCID: PMC3723492 DOI: 10.1371/journal.pcbi.1003156] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2013] [Accepted: 06/11/2013] [Indexed: 01/19/2023] Open
Abstract
Group VI Ca²⁺-independent phospholipase A₂ (iPLA₂) is a water-soluble enzyme that is active when associated with phospholipid membranes. Despite its clear pharmaceutical relevance, no X-ray or NMR structural information is currently available for the iPLA₂ or its membrane complex. In this paper, we combine homology modeling with coarse-grained (CG) and all-atom (AA) molecular dynamics (MD) simulations to build structural models of iPLA₂ in association with a phospholipid bilayer. CG-MD simulations of the membrane insertion process were employed to provide a starting point for an atomistic description. Six AA-MD simulations were then conducted for 60 ns, starting from different initial CG structures, to refine the membrane complex. The resulting structures are shown to be consistent with each other and with deuterium exchange mass spectrometry (DXMS) experiments, suggesting that our approach is suitable for the modeling of iPLA₂ at the membrane surface. The models show that an anchoring region (residues 710-724) forms an amphipathic helix that is stabilized by the membrane. In future studies, the proposed iPLA₂ models should provide a structural basis for understanding the mechanisms of lipid extraction and drug-inhibition. In addition, the dual-resolution approach discussed here should provide the means for the future exploration of the impact of lipid diversity and sequence mutations on the activity of iPLA₂ and related enzymes.
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Affiliation(s)
- Denis Bucher
- Department of Chemistry and Biochemistry, University of California, San Diego, La Jolla, California, United States of America.
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58
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Magrioti V, Nikolaou A, Smyrniotou A, Shah I, Constantinou-Kokotou V, Dennis EA, Kokotos G. New potent and selective polyfluoroalkyl ketone inhibitors of GVIA calcium-independent phospholipase A2. Bioorg Med Chem 2013; 21:5823-9. [PMID: 23916152 DOI: 10.1016/j.bmc.2013.07.010] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2013] [Accepted: 07/06/2013] [Indexed: 10/26/2022]
Abstract
Group VIA calcium-independent phospholipase A2 (GVIA iPLA2) has recently emerged as an important pharmaceutical target. Selective and potent GVIA iPLA2 inhibitors can be used to study its role in various neurological disorders. In the current work, we explore the significance of the introduction of a substituent in previously reported potent GVIA iPLA2 inhibitors. 1,1,1,2,2-Pentafluoro-7-(4-methoxyphenyl)heptan-3-one (GK187) is the most potent and selective GVIA iPLA2 inhibitor ever reported with a XI(50) value of 0.0001, and with no significant inhibition against GIVA cPLA2 or GV sPLA2. We also compare the inhibition of two difluoromethyl ketones on GVIA iPLA2, GIVA cPLA2, and GV sPLA2.
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Affiliation(s)
- Victoria Magrioti
- Laboratory of Organic Chemistry, Department of Chemistry, University of Athens, Panepistimiopolis, Greece
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59
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Yang D, Zhou Y, Xue N, Qu J. Synthesis of trifluoromethyl ketones via tandem Claisen condensation and retro-Claisen C-C bond-cleavage reaction. J Org Chem 2013; 78:4171-6. [PMID: 23517488 DOI: 10.1021/jo400280p] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
A highly efficient, operationally simple approach to trifluoromethyl ketones has been developed that builds on the use of a tandem process involving Claisen condensation and retro-Claisen C-C bond cleavage reaction. Enolizable alkyl phenyl ketones were found to react readily with ethyl trifuoroacetate under the promotion of NaH to afford trifluoroacetic ester/ketone exchange products, trifluoromethyl ketones, which were quite different from the general Claisen condensation products, β-diketones. This procedure uses readily available starting materials and can be extended to the preparation of perfluoroalkyl ketones in excellent yield.
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Affiliation(s)
- Dongmei Yang
- State Key Laboratory of Fine Chemicals, School of Pharmaceutical Science and Technology, Dalian University of Technology, Dalian 116024, P.R. China
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60
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Hsu YH, Dumlao DS, Cao J, Dennis EA. Assessing phospholipase A2 activity toward cardiolipin by mass spectrometry. PLoS One 2013; 8:e59267. [PMID: 23533611 PMCID: PMC3606342 DOI: 10.1371/journal.pone.0059267] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2012] [Accepted: 02/13/2013] [Indexed: 11/28/2022] Open
Abstract
Cardiolipin, a major component of mitochondria, is critical for mitochondrial functioning including the regulation of cytochrome c release during apoptosis and proper electron transport. Mitochondrial cardiolipin with its unique bulky amphipathic structure is a potential substrate for phospholipase A2 (PLA2) in vivo. We have developed mass spectrometric methodology for analyzing PLA2 activity toward various cardiolipin forms and demonstrate that cardiolipin is a substrate for sPLA2, cPLA2 and iPLA2, but not for Lp-PLA2. Our results also show that none of these PLA2s have significant PLA1 activities toward dilyso-cardiolipin. To understand the mechanism of cardiolipin hydrolysis by PLA2, we also quantified the release of monolyso-cardiolipin and dilyso-cardiolipin in the PLA2 assays. The sPLA2s caused an accumulation of dilyso-cardiolipin, in contrast to iPLA2 which caused an accumulation of monolyso-cardiolipin. Moreover, cardiolipin inhibits iPLA2 and cPLA2, and activates sPLA2 at low mol fractions in mixed micelles of Triton X-100 with the substrate 1-palmitoyl-2-arachidonyl-sn-phosphtidylcholine. Thus, cardiolipin functions as both a substrate and a regulator of PLA2 activity and the ability to assay the various forms of PLA2 is important in understanding its function.
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Affiliation(s)
- Yuan-Hao Hsu
- Department of Chemistry, Tunghai University, Taichung, Taiwan
- Department of Pharmacology, University of California San Diego, La Jolla, California, United States of America
- Department of Chemistry and Biochemistry, University of California San Diego, La Jolla, California, United States of America
- * E-mail: (EAD); (YHH)
| | - Darren S. Dumlao
- Department of Pharmacology, University of California San Diego, La Jolla, California, United States of America
- Department of Chemistry and Biochemistry, University of California San Diego, La Jolla, California, United States of America
| | - Jian Cao
- Department of Pharmacology, University of California San Diego, La Jolla, California, United States of America
- Department of Chemistry and Biochemistry, University of California San Diego, La Jolla, California, United States of America
| | - Edward A. Dennis
- Department of Pharmacology, University of California San Diego, La Jolla, California, United States of America
- Department of Chemistry and Biochemistry, University of California San Diego, La Jolla, California, United States of America
- * E-mail: (EAD); (YHH)
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61
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Hsu YH, Bucher D, Cao J, Li S, Yang SW, Kokotos G, Woods VL, McCammon JA, Dennis EA. Fluoroketone inhibition of Ca(2+)-independent phospholipase A2 through binding pocket association defined by hydrogen/deuterium exchange and molecular dynamics. J Am Chem Soc 2013; 135:1330-7. [PMID: 23256506 PMCID: PMC3561773 DOI: 10.1021/ja306490g] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
![]()
The mechanism of inhibition of group VIA Ca2+-independent
phospholipase A2 (iPLA2) by fluoroketone (FK)
ligands is examined by a combination of deuterium exchange mass spectrometry
(DXMS) and molecular dynamics (MD). Models for iPLA2 were
built by homology with the known structure of patatin and equilibrated
by extensive MD simulations. Empty pockets were identified during
the simulations and studied for their ability to accommodate FK inhibitors.
Ligand docking techniques showed that the potent inhibitor 1,1,1,3-tetrafluoro-7-phenylheptan-2-one
(PHFK) forms favorable interactions inside an active-site pocket,
where it blocks the entrance of phospholipid substrates. The polar
fluoroketone headgroup is stabilized by hydrogen bonds with residues
Gly486, Gly487, and Ser519. The nonpolar aliphatic chain and aromatic
group are stabilized by hydrophobic contacts with Met544, Val548,
Phe549, Leu560, and Ala640. The binding mode is supported by DXMS
experiments showing an important decrease of deuteration in the contact
regions in the presence of the inhibitor. The discovery of the precise
binding mode of FK ligands to the iPLA2 should greatly
improve our ability to design new inhibitors with higher potency and
selectivity.
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Affiliation(s)
- Yuan-Hao Hsu
- Department of Pharmacology, University of California, San Diego, La Jolla, California 92093-0601, USA.
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62
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Magrioti V, Kokotos G. Phospholipase A2inhibitors for the treatment of inflammatory diseases: a patent review (2010 – present). Expert Opin Ther Pat 2013; 23:333-44. [DOI: 10.1517/13543776.2013.754425] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
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63
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Tyurin VA, Yanamala N, Tyurina YY, Klein-Seetharaman J, Macphee CH, Kagan VE. Specificity of lipoprotein-associated phospholipase A(2) toward oxidized phosphatidylserines: liquid chromatography-electrospray ionization mass spectrometry characterization of products and computer modeling of interactions. Biochemistry 2012; 51:9736-50. [PMID: 23148485 DOI: 10.1021/bi301024e] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
Ca(2+)-independent lipoprotein-associated phospholipase A(2) (Lp-PLA(2)) is a member of the phospholipase A(2) superfamily with a distinguishing characteristic of high specificity for oxidatively modified sn-2 fatty acid residues in phospholipids that has been especially well characterized for peroxidized species of phosphatidylcholines (PC). The ability of Lp-PLA(2) to hydrolyze peroxidized species of phosphatidylserine (PS), acting as a recognition signal for clearance of apoptotic cells by professional phagocytes, as well as the products of the reaction has not been investigated. We performed liquid chromatography-electrospray ionization mass spectrometry-based structural characterization of oxygenated, hydrolyzed molecular species of PS-containing linoleic acid in either the sn-2 position (C(18:0)/C(18:2)) or in both sn-1 and sn-2 positions (C(18:2)/C(18:2)), formed in the cytochrome c- and H(2)O(2)-driven enzymatic oxidation reaction. Cytochrome c has been chosen as a catalyst of peroxidation reactions because of its likely involvement in PS oxidation in apoptotic cells. We found that Lp-PLA(2) catalyzed the hydrolysis of both nontruncated and truncated (oxidatively fragmented) species of oxidized PS species, albeit with different efficiencies, and performed detailed characterization of the major reaction products: oxygenated derivatives of linoleic acid as well as nonoxygenated and oxygenated species of lyso-PS. Among linoleic acid products, derivatives oxygenated at the C(9) position, including 9-hydroxyoctadecadienoic acid (9-HODE), a potent ligand of G protein-coupled receptor G2A, were the most abundant. Computer modeling of interactions of Lp-PLA(2) with different PS-oxidized species indicated that they are able to bind in the proximity (<5 Å) of Ser273 and His351 of the catalytic triad. For 9-hydroxy and 9-hydroperoxy derivatives of oxidized PS, the sn-2 ester bond was positioned very close (<3 Å) to the Ser273 residue, a nucleophile directly attacking the sn-2 bond, thus favoring the hydrolysis reaction. We suggest that oxidatively modified free fatty acids and lyso-PS species generated by Lp-PLA(2) may represent important signals facilitating and regulating the execution of apoptotic and phagocytosis programs essential for the control of inflammation.
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Affiliation(s)
- Vladimir A Tyurin
- Center for Free Radical and Antioxidant Health, University of Pittsburgh, Pittsburgh, PA 15260, USA.
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64
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Zhao YM, Cheung MS, Lin Z, Sun J. Enantioselective Synthesis of β,γ-Unsaturated α-Fluoroesters Catalyzed by N-Heterocyclic Carbenes. Angew Chem Int Ed Engl 2012. [DOI: 10.1002/ange.201204521] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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65
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Zhao YM, Cheung MS, Lin Z, Sun J. Enantioselective synthesis of β,γ-unsaturated α-fluoroesters catalyzed by N-heterocyclic carbenes. Angew Chem Int Ed Engl 2012; 51:10359-63. [PMID: 22965929 DOI: 10.1002/anie.201204521] [Citation(s) in RCA: 77] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2012] [Revised: 07/31/2012] [Indexed: 11/06/2022]
Affiliation(s)
- Yu-Ming Zhao
- Department of Chemistry, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong SAR, China
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66
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Prchalová E, Votruba I, Kotora M. Sphingosine and clavaminol H derivatives bearing fluorinated chains and their cytotoxic activity. J Fluor Chem 2012. [DOI: 10.1016/j.jfluchem.2012.06.005] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
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67
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68
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Kokotos CG. Construction of Tertiary Alcohols Bearing Perfluoroalkyl Chains Catalyzed by Prolinamide-Thioureas. J Org Chem 2012; 77:1131-5. [DOI: 10.1021/jo2020104] [Citation(s) in RCA: 67] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Christoforos G. Kokotos
- Laboratory
of Organic Chemistry, Department of Chemistry, University of Athens, Panepistimiopolis, Athens 15771,
Greece
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69
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Harkewicz R, Du H, Tong Z, Alkuraya H, Bedell M, Sun W, Wang X, Hsu YH, Esteve-Rudd J, Hughes G, Su Z, Zhang M, Lopes VS, Molday RS, Williams DS, Dennis EA, Zhang K. Essential role of ELOVL4 protein in very long chain fatty acid synthesis and retinal function. J Biol Chem 2011; 287:11469-80. [PMID: 22199362 DOI: 10.1074/jbc.m111.256073] [Citation(s) in RCA: 70] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Very long chain polyunsaturated fatty acid (VLC-PUFA)-containing glycerophospholipids are highly enriched in the retina; however, details regarding the specific synthesis and function of these highly unusual retinal glycerophospholipids are lacking. Elongation of very long chain fatty acids-4 (ELOVL4) has been identified as a fatty acid elongase protein involved in the synthesis of VLC-PUFAs. Mutations in ELOVL4 have also been implicated in an autosomal dominant form of Stargardt disease (STGD3), a type of juvenile macular degeneration. We have generated photoreceptor-specific conditional knock-out mice and used high performance liquid chromatography-mass spectrometry (HPLC-MS) to examine and analyze the fatty acid composition of retinal membrane glycerophosphatidylcholine and glycerophosphatidylethanolamine species. We also used immunofluorescent staining and histology coupled with electrophysiological data to assess retinal morphology and visual response. The conditional knock-out mice showed a significant decrease in retinal glycerophospholipids containing VLC-PUFAs, specifically contained in the sn-1 position of glycerophosphatidylcholine, implicating the role of Elovl4 in their synthesis. Conditional knock-out mice were also found to have abnormal accumulation of lipid droplets and lipofuscin-like granules while demonstrating photoreceptor-specific abnormalities in visual response, indicating the critical role of Elovl4 for proper rod or cone photoreceptor function. Altogether, this study demonstrates the essential role of ELOVL4 in VLC-PUFA synthesis and retinal function.
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Affiliation(s)
- Richard Harkewicz
- Department of Chemistry and Biochemistry, University of California, San Diego, La Jolla, California 92093, USA
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70
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Dennis EA, Cao J, Hsu YH, Magrioti V, Kokotos G. Phospholipase A2 enzymes: physical structure, biological function, disease implication, chemical inhibition, and therapeutic intervention. Chem Rev 2011; 111:6130-85. [PMID: 21910409 PMCID: PMC3196595 DOI: 10.1021/cr200085w] [Citation(s) in RCA: 820] [Impact Index Per Article: 63.1] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Affiliation(s)
- Edward A. Dennis
- Department of Chemistry and Biochemistry and Pharmacology, School of Medicine, University of California, San Diego, La Jolla, California 92093-0601
| | - Jian Cao
- Department of Chemistry and Biochemistry and Pharmacology, School of Medicine, University of California, San Diego, La Jolla, California 92093-0601
| | - Yuan-Hao Hsu
- Department of Chemistry and Biochemistry and Pharmacology, School of Medicine, University of California, San Diego, La Jolla, California 92093-0601
| | - Victoria Magrioti
- Laboratory of Organic Chemistry, Department of Chemistry, University of Athens, Panepistimiopolis, Athens 15771, Greece
| | - George Kokotos
- Laboratory of Organic Chemistry, Department of Chemistry, University of Athens, Panepistimiopolis, Athens 15771, Greece
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