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Li FY, Zhang ZF, Voss S, Wu YW, Zhao YF, Li YM, Chen YX. Inhibition of K-Ras4B-plasma membrane association with a membrane microdomain-targeting peptide. Chem Sci 2019; 11:826-832. [PMID: 34123058 PMCID: PMC8145430 DOI: 10.1039/c9sc04726c] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
The association of K-Ras4B protein with plasma membrane (PM) is required for its signaling activity. Thus, direct inhibition of K-Ras4B–PM interaction could be a potential anti-Ras therapeutic strategy. However, it remains challenging to modulate such protein–PM interaction. Based on Ras isoform-specific PM microdomain localization patterns, we have developed a potent and isoform-selective peptide inhibitor, Memrasin, for detachment of K-Ras4B from the PM. Memrasin is one of the first direct inhibitors of K-Ras4B–PM interaction, and consists of a membrane ld region-binding sequence derived from the C-terminal region of K-Ras4B and an endosome-escape enhancing motif that can aggregate on membrane. It forms peptide-enriched domains in the ld region, abrogates the tethering of K-Ras4B to the PM and accordingly impairs Ras signaling activity, thereby efficiently decreasing the viability of several human lung cancer cells in a dose-responsive and K-Ras dependent manner. Memrasin provides a useful tool for exploring the biological function of K-Ras4B on or off the PM and a potential starting point for further development into anti-Ras therapeutics. A membrane ld microdomain-targeting hybrid peptide displays potent inhibition effect toward K-Ras4B-plasma membrane interaction and impairs Ras signaling output.![]()
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Affiliation(s)
- Fang-Yi Li
- Key Laboratory of Bioorganic Phosphorus Chemistry and Chemical Biology (Ministry of Education), Department of Chemistry, Tsinghua University Beijing 100084 China
| | - Zhen-Feng Zhang
- State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences No. 1 West Beichen Road, Chaoyang District Beijing 100101 China
| | - Stephanie Voss
- Chemical Genomics Centre of the Max Planck Society Otto-Hahn-Str. 15 44227 Dortmund Germany.,Max-Planck-Institute of Molecular Physiology Otto-Hahn-Str. 11 44227 Dortmund Germany
| | - Yao-Wen Wu
- Chemical Genomics Centre of the Max Planck Society Otto-Hahn-Str. 15 44227 Dortmund Germany.,Max-Planck-Institute of Molecular Physiology Otto-Hahn-Str. 11 44227 Dortmund Germany.,Department of Chemistry, Umeå University 90187 Umeå Sweden
| | - Yu-Fen Zhao
- Key Laboratory of Bioorganic Phosphorus Chemistry and Chemical Biology (Ministry of Education), Department of Chemistry, Tsinghua University Beijing 100084 China
| | - Yan-Mei Li
- Key Laboratory of Bioorganic Phosphorus Chemistry and Chemical Biology (Ministry of Education), Department of Chemistry, Tsinghua University Beijing 100084 China
| | - Yong-Xiang Chen
- Key Laboratory of Bioorganic Phosphorus Chemistry and Chemical Biology (Ministry of Education), Department of Chemistry, Tsinghua University Beijing 100084 China
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Summer A, Formaggioni P, Franceschi P, Di Frangia F, Righi F, Malacarne M. Cheese as Functional Food: The Example of Parmigiano Reggiano and Grana Padano. Food Technol Biotechnol 2017; 55:277-289. [PMID: 29089844 DOI: 10.17113/ftb.55.03.17.5233] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
Italian hard cooked types of cheese, like Parmigiano Reggiano and Grana Padano, are characterised by positive nutritional qualities. In fact, they contain substances that have particular biological activities, and therefore they can be fully considered, according to the definition given by the European Unit, as 'functional' foods. This short review concisely describes these components and the beneficial effects related to their activities. The description of the biologically active components has been organised in the following paragraphs: protein and peptides, fat and lipids, carbohydrates and prebiotics, probiotic bacteria, vitamins, mineral salts, and components of dairy products active in disease prevention. In particular, several known bioactive peptides were found in Parmigiano Reggiano cheese samples: for example, phosphopeptides, which are known for their mineral-binding capacity and vehiculation activity, peptides with immunomodulatory activity, and angiotensin-converting enzyme-inhibitory peptides with anti-hypertensive effects. Among lipids, the role of conjugated linoleic acid and other fatty acids present in these cheese types was taken into consideration. The presence of oligosaccharides with prebiotic properties and probiotic bacteria was also described. Finally, particular emphasis was given to highly available calcium and its impact on bone health.
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Affiliation(s)
- Andrea Summer
- Department of Veterinary Science, University of Parma, Strada del Taglio 10, IT-43126 Parma, Italy.,MILC Center, University of Parma, Parco Area delle Scienze 59/A, IT-43124 Parma, Italy
| | - Paolo Formaggioni
- Department of Veterinary Science, University of Parma, Strada del Taglio 10, IT-43126 Parma, Italy
| | - Piero Franceschi
- Department of Veterinary Science, University of Parma, Strada del Taglio 10, IT-43126 Parma, Italy
| | - Federica Di Frangia
- Department of Veterinary Science, University of Parma, Strada del Taglio 10, IT-43126 Parma, Italy
| | - Federico Righi
- Department of Veterinary Science, University of Parma, Strada del Taglio 10, IT-43126 Parma, Italy
| | - Massimo Malacarne
- Department of Veterinary Science, University of Parma, Strada del Taglio 10, IT-43126 Parma, Italy.,MILC Center, University of Parma, Parco Area delle Scienze 59/A, IT-43124 Parma, Italy
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3
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Kokotos G, Martin V, Constantinou-Kokotou V, Gibbons WA. Synthesis of medicinally useful lipidicα-amino acids, 2-amino alcohols and diamines. Amino Acids 2013; 11:329-43. [PMID: 24178720 DOI: 10.1007/bf00807940] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/1996] [Accepted: 04/28/1996] [Indexed: 11/27/2022]
Abstract
The lipidicα-amino acids (LAAs) are non-naturalα-amino acids with saturated or unsaturated long aliphatic side chains. LAAs and their derivatives (lipid mimetics) together with the lipidic peptides represent a class of compounds which combine structural features of lipids with those of amino acids and peptides. Racemic LAAs may be prepared by classical methods and resolved by chemical or enzymatic methods. LAA amides and esters with saturated or unsaturated long chain amines and alcohols respectively, as well as lipidic dipeptide derivatives inhibit both pancreatic and human platelet phospholipase A2. Lipophilic peptide derivatives are inhibitors of human neutrophil elastase. LAAs and their oligomers have been used as drug delivery system. A Lipid-Core-Peptide system has been designed and used as a combined adjuvant-carrier-vaccine system. A variety of lipid mimetics such as lipidic 2-amino alcohols, lipidic 1,2- and 1,3-diamines have been prepared based upon LAAs. Some of them are potent inhibitors of phospholipase A2. A general approach to enantioselective synthesis of LAAs and lipid mimetics is based on the oxidative cleavage of 3-amino-1,2-diols obtained by the regioselective opening of enantiomerically enriched long chain 2,3-epoxy alcohols.
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Affiliation(s)
- G Kokotos
- Laboratory of Organic Chemistry, Department of Chemistry, University of Athens, Panepistimiopolis, GR-15771, Athens, Greece
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4
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The effect of long-chain bases on polysialic acid-mediated membrane interactions. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2011; 1808:2322-6. [DOI: 10.1016/j.bbamem.2011.05.008] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/27/2011] [Revised: 05/04/2011] [Accepted: 05/10/2011] [Indexed: 11/20/2022]
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5
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Georgieva R, Koumanov K, Momchilova A, Tessier C, Staneva G. Effect of sphingosine on domain morphology in giant vesicles. J Colloid Interface Sci 2010; 350:502-10. [DOI: 10.1016/j.jcis.2010.07.022] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2010] [Revised: 07/09/2010] [Accepted: 07/10/2010] [Indexed: 02/04/2023]
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6
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Goñi FM, Alonso A. Biophysics of sphingolipids I. Membrane properties of sphingosine, ceramides and other simple sphingolipids. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2006; 1758:1902-21. [PMID: 17070498 DOI: 10.1016/j.bbamem.2006.09.011] [Citation(s) in RCA: 206] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Received: 06/09/2006] [Revised: 09/15/2006] [Accepted: 09/18/2006] [Indexed: 12/16/2022]
Abstract
Some of the simplest sphingolipids, namely sphingosine, ceramide, some closely related molecules (eicosasphingosine, phytosphingosine), and their phosphorylated compounds (sphingosine-1-phosphate, ceramide-1-phosphate), are potent metabolic regulators. Each of these lipids modifies in marked and specific ways the physical properties of the cell membranes, in what can be the basis for some of their physiological actions. This paper reviews the mechanisms by which these sphingolipid signals, sphingosine and ceramide in particular, are able to modify the properties of cell membranes.
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Affiliation(s)
- Félix M Goñi
- Unidad de Biofísica (Centro Mixto CSIC-UPV/EHU), Departamento de Bioquímica, Universidad del País Vasco, Aptdo. 644, 48080 Bilbao, Spain.
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7
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Meyer SGE, Karow W, de Groot H. 2n-fatty acids from phosphatidylcholine label sphingolipids—A novel role of phospholipase A2? Biochim Biophys Acta Mol Cell Biol Lipids 2005; 1735:68-78. [PMID: 15950537 DOI: 10.1016/j.bbalip.2005.04.008] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2005] [Revised: 04/26/2005] [Accepted: 04/26/2005] [Indexed: 10/25/2022]
Abstract
In order to find out whether there is a phospholipase A2 (PLA2)-mediated link between glycerophospholipids and sphingolipids, L929 cells were labeled with 1n-palmitoyl-2n-[1-14C]palmitoyl phosphatidylcholine for 16-18 h or 90 min. After labeling for 16-18 h, 14C-sphingomyelin (SM), 14C-ceramide and 14C-sphingosine were demonstrated on autoradiograms of thin layer chromatograms of untreated or mildly hydrolyzed lipid extracts in different chromatographic systems. Strong hydrolysis of labeled SM proved that both possible moieties of SM, sphingosine and acyl moiety, had been labeled. The identity of SM and its enzymatic degradation product, ceramide, was verified by mass spectrometry. The label in SM-derived ceramide was demonstrated on an autoradiogram after thin layer chromatography. The inhibitor of (dihydro)ceramide synthase fumonisin B1 suppressed the label in sphingolipids significantly during 16-18 h (ceramide and SM), as well as during 90-min labeling (SM). The presence of inhibitors of PLA2 (bromoenol lactone, aristolochic acid and quinacrine dihydrochloride) diminished the label in SM significantly during the 90-min labeling. These results demonstrate a close metabolic relationship between glycerophospholipids and sphingolipids and give evidence for a novel role of PLA2.
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Affiliation(s)
- Sybille G E Meyer
- Institut für Physiologische Chemie, Universitätsklinikum Essen, Hufelandstr. 55, D-45147 Essen, Germany.
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8
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Nakamura H, Hirabayashi T, Someya A, Shimizu M, Murayama T. Inhibition of arachidonic acid release and cytosolic phospholipase A2 alpha activity by D-erythro-sphingosine. Eur J Pharmacol 2004; 484:9-17. [PMID: 14729377 DOI: 10.1016/j.ejphar.2003.10.053] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Sphingolipid metabolites such as sphingosine 1-phosphate (S1P) and ceramide can mediate many cellular events including apoptosis, stress responses and growth arrest. Although ceramide stimulates arachidonic acid metabolism in several cells, the effects of sphingosine and its endogenous analogs have not been established. We investigated the effects of D-erythro-sphingosine and its metabolites on arachidonic acid release in the two cells and on the activity of cytosolic phospholipase A2alpha. C2-Ceramide (N-acetyl-D-erythro-sphingosine, 100 microM) alone stimulated [3H]arachidonic acid release and enhanced the ionomycin-induced release from the prelabeled PC12 cells and L929 cells. In contrast, exogenous addition of D-erythro-sphingosine inhibited the responses in a concentration-dependent manner in the two cell lines. D-erythro-sphingosine, D-erythro-N,N-dimethylsphingosine (D-erythro-DMS) and D-erythro-dihydrosphingosine (D-erythro-DHS) significantly inhibited mastoparan-, but not Na3VO4-, stimulated arachidonic acid release in PC12 cells. D-erythro-S1P and DL-threo-DHS showed no effect on the responses. Production of prostaglandin F2alpha was also enhanced by C2-ceramide (20 microM) and suppressed by D-erythro-sphingosine (10 microM) in PC12 cells. An in vitro study revealed that D-erythro-sphingosine, D-erythro-DMS and D-erythro-DHS directly inhibited cytosolic phospholipase A2alpha activity. These findings suggest that ceramide and D-erythro-analogs of sphingosine have opposite effects on phospholipase A2 activity and thus regulate arachidonic acid release from cells.
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Affiliation(s)
- Hiroyuki Nakamura
- Laboratory of Chemical Pharmacology, Graduate School of Pharmaceutical Sciences, Chiba University, 263-8522, Chiba, Japan
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9
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Boyan BD, Sylvia VL, Dean DD, Del Toro F, Schwartz Z. Differential regulation of growth plate chondrocytes by 1alpha,25-(OH)2D3 and 24R,25-(OH)2D3 involves cell-maturation-specific membrane-receptor-activated phospholipid metabolism. CRITICAL REVIEWS IN ORAL BIOLOGY AND MEDICINE : AN OFFICIAL PUBLICATION OF THE AMERICAN ASSOCIATION OF ORAL BIOLOGISTS 2003; 13:143-54. [PMID: 12097357 DOI: 10.1177/154411130201300205] [Citation(s) in RCA: 61] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
This review discusses the regulation of growth plate chondrocytes by vitamin D(3). Over the past ten years, our understanding of how two vitamin D metabolites, 1alpha,25-(OH)(2)D(3) and 24R,25-(OH)(2)D(3), exert their effects on endochondral ossification has undergone considerable advances through the use of cell biology and signal transduction methodologies. These studies have shown that each metabolite affects a primary target cell within the endochondral developmental lineage. 1alpha,25-(OH)(2)D(3) affects primarily growth zone cells, and 24R,25-(OH)(2)D(3) affects primarily resting zone cells. In addition, 24R,25-(OH)(2)D(3) initiates a differentiation cascade that results in down-regulation of responsiveness to 24R,25-(OH)(2)D(3) and up-regulation of responsiveness to 1alpha,25-(OH)(2)D(3). 1alpha,25-(OH)(2)D(3) regulates growth zone chondrocytes both through the nuclear vitamin D receptor, and through a membrane-associated receptor that mediates its effects via a protein kinase C (PKC) signal transduction pathway. PKCalpha is increased via a phosphatidylinositol-specific phospholipase C (PLC)-dependent mechanism, as well as through the stimulation of phospholipase A(2) (PLA(2)) activity. Arachidonic acid and its downstream metabolite prostaglandin E(2) (PGE(2)) also modulate cell response to 1alpha,25-(OH)(2)D(3). In contrast, 24R,25-(OH)(2)D(3) exerts its effects on resting zone cells through a separate, membrane-associated receptor that also involves PKC pathways. PKCalpha is increased via a phospholipase D (PLD)-mediated mechanism, as well as through inhibition of the PLA(2) pathway. The target-cell-specific effects of each metabolite are also seen in the regulation of matrix vesicles by vitamin D(3). However, the PKC isoform involved is PKCzeta, and its activity is inhibited, providing a mechanism for differential autocrine regulation of the cell and events in the matrix by these two vitamin D(3) metabolites.
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Affiliation(s)
- B D Boyan
- Departments of Orthopaedics, Periodontics, Biochemistry, and Orthodontics, The University of Texas Health Science Center at San Antonio, 7703 Floyd Curl Drive, MS-7774, San Antonio, TX 78229-3900, USA.
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10
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Oshida K, Shimizu T, Takase M, Tamura Y, Shimizu T, Yamashiro Y. Effects of dietary sphingomyelin on central nervous system myelination in developing rats. Pediatr Res 2003; 53:589-93. [PMID: 12612207 DOI: 10.1203/01.pdr.0000054654.73826.ac] [Citation(s) in RCA: 122] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Human milk contains sphingomyelin (SM) as a major component of the phospholipid fraction. Galactosylceramide (cerebroside), a metabolite of sphingolipids, increases along with CNS myelination, and is generally considered a universal marker of myelination in all vertebrates. l-Cycloserine (LCS) is an inhibitor of serine palmitoyltransferase (SPT), a rate-limiting enzyme for sphingolipid biosynthesis that is reported to show increased activity with development of the rat CNS. The present study examined the effects of dietary SM on CNS myelination during development in LCS-treated rats. From 8 d after birth, Wistar rat pups received a daily s.c. injection (100 mg/kg) of LCS. From 17 d after birth, the animals were fed an 810 mg/100g of bovine SM-supplemented diet (SM-LCS group) or a nonsupplemented diet (LCS group). At 28 d after birth, the animals were killed and subjected to biochemical and morphometric analyses. The myelin dry weight, myelin total lipid content, and cerebroside content were significantly lower in the SM-LCS and LCS groups than in a group not treated with LCS (the non-LCS group). However, these levels were significantly higher in the SM-LCS group than in the LCS group. Morphometric analysis of the optic nerve revealed that the axon diameter, nerve fiber diameter, myelin thickness, and g value (used to compare the relative thickness of myelin sheaths around fibers of different diameter) were significantly lower in the LCS group than in the other groups, but were similar in the SM-LCS and non-LCS groups. These findings suggest that dietary SM contributes to CNS myelination in developing rats with experimental inhibition of SPT activity corrected].
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Affiliation(s)
- Kyoichi Oshida
- Nutritional Science Laboratory, Morinaga Milk Industry Co., Ltd., Zama, Kanagawa, Japan.
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Borioli GA, Fanani ML, Caputto BL, Maggio B. c-Fos is a surface pressure-dependent diverter of phospholipase activity. Biochem Biophys Res Commun 2002; 295:964-9. [PMID: 12127989 DOI: 10.1016/s0006-291x(02)00798-2] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
c-Fos, a transcription factor, associates to endoplasmic reticulum and modulates phospholipid biosynthesis. Its surface thermodynamic properties allow it to differentially interact with phospholipid monolayers with a selective dependence on the lipid polar head group and the lateral surface pressure. We explored the c-Fos ability to modulate phospholipid degradation by phospholipases (ppPLA2, Bacillus cereus PLC, and sphingomyelinase) using the monolayer technique. Experiments conducted under constant packing conditions show that c-Fos modulates phospholipase activity in a finely tuned way, depending on the membrane intermolecular packing. Surface lateral pressures above 12-16 mN/m induce c-Fos to activate phospholipase A2 and sphingomyelinase, and abolish phospholipase C activity. The effects of c-Fos on other steps of the catalytic process, lag-time and extent, are synergic with those on activity. We show for the first time that c-Fos participates in modulating phospholipid degradation and that it can affect the formation of lipid second messenger products by PLA2, PLC, and sphingomyelinase.
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Affiliation(s)
- Graciela A Borioli
- Departamento de Química Biológica, Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, Pabellón Argentina, Ciudad Universitaria, Córdoba, Argentina.
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12
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Schwartz Z, Sylvia VL, Luna MH, DeVeau P, Whetstone R, Dean DD, Boyan BD. The effect of 24R,25-(OH)(2)D(3) on protein kinase C activity in chondrocytes is mediated by phospholipase D whereas the effect of 1alpha,25-(OH)(2)D(3) is mediated by phospholipase C. Steroids 2001; 66:683-94. [PMID: 11546556 DOI: 10.1016/s0039-128x(01)00100-3] [Citation(s) in RCA: 43] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
1alpha,25-(OH)(2)D(3) regulates protein kinase C (PKC) activity in growth zone chondrocytes by stimulating increased phosphatidylinositol-specific phospholipase C (PI-PLC) activity and subsequent production of diacylglycerol (DAG). In contrast, 24R,25-(OH)(2)D(3) regulates PKC activity in resting zone (RC) cells, but PLC does not appear to be involved, suggesting that phospholipase D (PLD) may play a role in DAG production. In the present study, we examined the role of PLD in the physiological response of RC cells to 24R,25-(OH)(2)D(3) and determined the role of phospholipases D, C, and A(2) as well as G-proteins in mediating the effects of vitamin D(3) metabolites on PKC activity in RC and GC cells. Inhibition of PLD with wortmannin or EDS caused a dose-dependent inhibition of basal [3H]-thymidine incorporation by RC cells and further increased the inhibitory effect of 24R,25-(OH)(2)D(3). Wortmannin also inhibited basal alkaline phosphatase activity and [35]-sulfate incorporation and decreased the stimulatory effect of 24R,25-(OH)(2)D(3). This inhibitory effect of wortmannin was not seen in cultures treated with the PI-3-kinase inhibitor LY294002, verifying that wortmannin affected PLD. Wortmannin also inhibited basal PKC activity and partially blocked the stimulatory effect of 24R,25-(OH)(2)D(3) on this enzyme activity. Neither inhibition of PI-PLC with U73122, nor PC-PLC with D609, modulated PKC activity. Wortmannin had no effect on basal PLD in GC cells, nor on 1alpha,25-(OH)(2)D(3)-dependent PKC. Inhibition of PI-PLC blocked the 1alpha,25-(OH)(2)D(3)-dependent increase in PKC activity but inhibition of PC-PLC had no effect. Activation of PLA(2) with melittin inhibited basal and 24R,25-(OH)(2)D(3)-stimulated PKC in RC cells and stimulated basal and 1alpha,25-(OH)(2)D(3)-stimulated PKC in GC cells, but wortmannin had no effect on the melittin-induced changes in either cell type. Pertussis toxin modestly increased the effect of 24R,25-(OH)(2)D(3) on PKC, whereas GDPbetaS had no effect, suggesting that PLD2 is the isoform responsible. This indicates that 1alpha,25-(OH)(2)D(3) regulates PKC in GC cells via PI-PLC and PLA(2), but not PC-PLC or PLD, whereas 24R,25-(OH)(2)D(3) regulates PKC in RC cells via PLD2.
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Affiliation(s)
- Z Schwartz
- Department of Orthopaedics, The University of Texas Health Science Center at San Antonio, 78284, USA
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Touyz RM, Schiffrin EL. Increased generation of superoxide by angiotensin II in smooth muscle cells from resistance arteries of hypertensive patients: role of phospholipase D-dependent NAD(P)H oxidase-sensitive pathways. J Hypertens 2001; 19:1245-54. [PMID: 11446714 DOI: 10.1097/00004872-200107000-00009] [Citation(s) in RCA: 211] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
OBJECTIVE We tested the hypothesis that increased responsiveness of phospholipase D (PLD) to angiotensin II (Ang II) is associated with increased oxidative stress and exaggerated growth responses in vascular smooth muscle cells (VSMC) from untreated essential hypertensive patients. DESIGN VSMCs from peripheral resistance arteries of normotensive and hypertensive subjects were studied. Production of reactive oxygen species (ROS) was measured with the fluoroprobe 5-(and 6)-chloromethyl-2',7'-dichlorodihydrofluorescein diacetate (CM-H2DCFDA). PLD and reduced nicotinamide adenine dinucleotide (phosphate) (NAD(P)H) oxidase were assessed with the inhibitors, dihydro-D-erythro-sphingosine (sphinganine) and diphenylene iodinium (DPI), respectively, and protein kinase C (PKC) effects were determined using chelerythrine chloride and calphostin C. PLD activity was measured by the transphosphatidylation assay. RESULTS Ang II increased the CM-H2DCFDA fluorescence signal, derived predominantly from H2O2. Ang II-induced generation of DPI-inhibitable ROS was significantly enhanced in cells from hypertensives compared with normotensives (Emax = 72 +/- 2 versus 56.9 +/- 1.8 fluorescence units, P< 0.01). PLD inhibition attenuated Ang II-induced ROS generation, with greater effects in the hypertensive group than the normotensive group (delta = 42 +/- 3.3 versus 21 +/- 2 units). PKC inhibition partially decreased Ang II-elicited signals. Ang II-stimulated PLD activity and DNA and protein synthesis were significantly greater in cells from hypertensives than normotensives. These effects were normalized by DPI and sphinganine. CONCLUSIONS Our results suggest that in essential hypertension enhanced oxidative stress and augmented growth-promoting actions of Ang II are associated with increased activation of PLD-dependent pathways. These processes may contribute to vascular remodeling in hypertension.
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Affiliation(s)
- R M Touyz
- Clinical Research Institute of Montreal, University of Montreal, Canada.
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14
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Sylvia VL, Schwartz Z, Del Toro F, DeVeau P, Whetstone R, Hardin RR, Dean DD, Boyan BD. Regulation of phospholipase D (PLD) in growth plate chondrocytes by 24R,25-(OH)2D3 is dependent on cell maturation state (resting zone cells) and is specific to the PLD2 isoform. BIOCHIMICA ET BIOPHYSICA ACTA 2001; 1499:209-21. [PMID: 11341968 DOI: 10.1016/s0167-4889(00)00120-8] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
Many of the effects of 1alpha,25-(OH)2D3 and 24R,25-(OH)2D3 on costochondral chondrocytes are mediated by the protein kinase C (PKC) signal transduction pathway. 1alpha,25-(OH)2D3 activates PKC in costochondral growth zone chondrocytes through a specific membrane receptor (1alpha,25-mVDR), involving rapid increases in diacylglycerol via a phospholipase C (PLC)-dependent mechanism. 24R,25-(OH)2D3 activates PKC in resting zone chondrocytes. Although diacylglycerol is increased by 24R,25-(OH)2D3, PLC is not involved, suggesting a phospholipase D (PLD)-dependent mechanism. Here, we show that resting zone and growth zone cells express mRNAs for PLD1a, PLD1b, and PLD2. Both cell types have PLD activity, but levels are higher in resting zone cells. 24R,25-(OH)2D3, but not 24S,25-(OH)2D3 or 1alpha,25-(OH)2D3, stimulates PLD activity in resting zone cells within 3 min via nongenomic mechanisms. Neither 1alpha,25-(OH)2D3 nor 24R,25-(OH)2D3 affected PLD in growth zone cells. Basal and 24R,25-(OH)2D3-stimulated PLD were inhibited by the PLD inhibitors wortmannin and EDS. Inhibition of phosphatidylinositol 3-kinase (PI 3-kinase), PKC, phosphatidylinositol-specific PLC (PI-PLC), and phosphatidylcholine-specific PLC (PC-PLC) had no effect on PLD activity. Thus, 24R,25-(OH)2D3 stimulates PLD, and PI 3-kinase, PI-PLC and PKC are not involved, whereas PLD is required for stimulation of PKC by 24R,25-(OH)2D3. Pertussis toxin, GDPbetaS, and GTPgammaS had no effect on 24R,25-(OH)2D3-dependent PLD when added to cell cultures, indicating that G-proteins are not involved. These data show that PKC activation in resting zone cells is mediated by PLD and suggest that a functional 24R,25-(OH)2D3-mVDR is required. The results also support the conclusion that the 24R,25-(OH)2D3-responsive PLD is PLD2, since this PLD isoform is G-protein-independent.
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Affiliation(s)
- V L Sylvia
- Department of Orthopaedics, University of Texas Health Science Center at San Antonio, TX 78229-3900, USA
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15
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Touyz RM, Schiffrin EL. Ang II-stimulated superoxide production is mediated via phospholipase D in human vascular smooth muscle cells. Hypertension 1999; 34:976-82. [PMID: 10523394 DOI: 10.1161/01.hyp.34.4.976] [Citation(s) in RCA: 137] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Intracellular signaling events that mediate the long-term effects of Ang II in vascular smooth muscle cells are unclear, but oxidative stress may play an important role. This study examined the ability of Ang II to generate reactive oxygen species and investigated the putative role of phospholipase D (PLD)-dependent signaling pathways for its production in human vascular smooth muscle cells. In addition, we assessed whether redox-sensitive pathways influence Ang II-stimulated cell growth. Primary and low-passage cells (passages 1 to 4) derived from resistance arteries of subcutaneous gluteal biopsies from healthy subjects were studied. Oxidative stress was measured with the fluorescent probe 5-(and 6)-chloromethyl-2', 7'-dichlorodihydrofluorescein diacetate (CM-H(2)DCFDA) (8 micromol/L), and the role of PLD was assessed with the PLD inhibitor D-erythro-sphingosine, dihydro (sphinganine) (10 micromol/L). To determine whether NADH/NADPH oxidase contributes to production of reactive oxygen species, Ang II-stimulated cells were pretreated with the specific flavoprotein inhibitor diphenylene iodinium (DPI) (10 micromol/L). DNA and protein synthesis were determined by [(3)H]thymidine and [(3)H]leucine incorporation, respectively. Ang II increased CM-H(2)DCFDA fluorescence, and this was inhibited by catalase (350 U/mL), indicating that the fluorescence signal was derived predominantly from H(2)O(2). Ang II dose-dependently increased H(2)O(2) production (E(max)=57.6+/-1.7 nmol/L, pD(2)=7.7+/-0.06) and PLD activation (E(max)=207+/-3.3% of control, pD(2)=7.7+/-0.5). H(2)O(2) effects were evident within 1 hour, and maximal PLD activation occurred within 40 minutes after stimulation. DPI inhibited (P<0.01) Ang II-stimulated responses. PLD inhibition significantly attenuated (P<0.05) Ang II-elicited H(2)O(2) production (E(max)=29+/-5 nmol/L). DPI and sphinganine inhibited Ang II-induced DNA and protein synthesis. These data indicate that in vascular smooth muscle cells from human peripheral resistance arteries, Ang II increases H(2)O(2) generation via PLD-dependent, NADH/NADPH oxidase-sensitive pathways. These cascades may function as second messengers in long-term Ang II-mediated growth-signaling events.
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Affiliation(s)
- R M Touyz
- Experimental Hypertension Laboratory, MRC Multidisciplinary Research Group on Hypertension, Clinical Research Institute of Montreal and Université de Montréal, Montreal, Quebec, Canada H2W 1R7.
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16
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Constantinou-Kokotou V, Kokotos G. Synthesis of optically active lipidic alpha-amino acids and lipidic 2-amino alcohols. Amino Acids 1999; 16:273-85. [PMID: 10399016 DOI: 10.1007/bf01388172] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Lipidic alpha-amino acids (LAAs) are a class of compounds combining structural features of amino acids with those of fatty acids. They are non-natural alpha-amino acids with saturated or unsaturated long aliphatic side chains. Synthetic approaches to optically active LAAs and lipidic 2-amino alcohols (LAALs) are summarized in this review. A general approach to enantioselective synthesis of saturated LAAs is based on the oxidative cleavage of 3-amino-1,2-diols obtained by the regioselective opening of enantiomerically enriched long chain 2,3-epoxy alcohols. Unsaturated LAAs are prepared in their enantiomeric forms by Wittig reaction via methyl (S)-2-di-tert-butoxycarbonylamino-5-oxo-pentanoate. This key intermediate aldehyde is obtained by selective reduction of dimethyl N,N-di-Boc glutamate with DIBAL. (R) or (S) LAALs may be prepared starting from D-mannitol or L-serine. LAAs are converted into LAALs by chemoselective reduction of their fluorides using sodium borohydride with retention of optical purity. Replacement of the hydroxyl group of LAALs by the azido group, followed by selective reduction leads to unsaturated optically active lipidic 1,2-diamines.
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17
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Ghidoni R, Sala G, Giuliani A. Use of sphingolipid analogs: benefits and risks. BIOCHIMICA ET BIOPHYSICA ACTA 1999; 1439:17-39. [PMID: 10395962 DOI: 10.1016/s1388-1981(99)00074-8] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Affiliation(s)
- R Ghidoni
- INSERM U410, Neuroendocrinologie et Biologie Cellulaire Digestives, Faculté de Médecine Xavier Bichat, Paris, France.
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18
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Maggio B. Modulation of phospholipase A2 by electrostatic fields and dipole potential of glycosphingolipids in monolayers. J Lipid Res 1999. [DOI: 10.1016/s0022-2275(20)32128-3] [Citation(s) in RCA: 44] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
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19
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Padrón JM, Martin VS, Hadjipavlou-Litina D, Noula C, Constantinou-Kokotou V, Peters GJ, Kokotos G. Synthesis, in vitro cytotoxicity and in vivo anti-inflammatory activity of long chain 3-amino-1,2-diols. Bioorg Med Chem Lett 1999; 9:821-6. [PMID: 10206543 DOI: 10.1016/s0960-894x(99)00084-0] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
The synthesis of long chain 3-amino-1,2-diols was carried out based on Sharpless asymmetric epoxidation of long chain allylic alcohols and regioselective nucleophilic ring opening by azido group. The in vitro cytotoxicity of the compounds prepared was evaluated against six solid tumor cell lines (A2780, H322, LL, WiDr, C26-10, UMSCC-22B). Free 3-amino-1,2-diols exhibited IC50 values between 1.45 microM and 32 microM. These compounds also presented interesting inhibition of carrageenin-induced paw edema in rats (85.3% - 79.6% at a concentration of 0.15 mmol/kg).
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Affiliation(s)
- J M Padrón
- Instituto Universitario de Bio-Orgánica Antonio González, Universidad de La Laguna, Tenerife, Spain
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20
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Koumanov KS, Quinn PJ, Béréziat G, Wolf C. Cholesterol relieves the inhibitory effect of sphingomyelin on type II secretory phospholipase A2. Biochem J 1998; 336 ( Pt 3):625-30. [PMID: 9841874 PMCID: PMC1219913 DOI: 10.1042/bj3360625] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Secretory type II phospholipase A2 (sPLA2) is inhibited by sphingomyelin (SPH); cholesterol either mixed with the model glycerophospholipid substrate or added to the assay medium as separated liposomes counteracts this inhibition efficiently. The inhibition of fatty acid release assayed by quantitative gas chromatography-MS is observed when SPH is added to erythrocyte membranes as the substrate instead of a readily hydrolysable phosphatidylethanolamine/phosphatidylserine model mixture. Hydrolysis of SPH by Staphylococcus aureus sphingomyelinase suppresses its inhibitory potency. The addition of cholesterol to SPH liposomes with a 1:1 stoichiometry relieves completely the inhibition of sPLA2 exerted by SPH. The mechanism of inhibition suggested by the binding assay is that sPLA2 binds with affinity to the SPH interface, after either phase segregation at the assay temperature or on the pure SPH liposomes added to the incubation medium. Cholesterol is shown to suppress the binding affinity of the enzyme for the SPH interface. A model for inhibition is suggested in which binding of the sphingosine moiety is competitive for sPLA2 (inhibition) or for cholesterol (release of the enzyme).
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Affiliation(s)
- K S Koumanov
- Laboratoire de Biochimie, URA CNRS 1283, Faculté de Médecine Saint Antoine, Université Pierre et Marie Curie, 27 rue Chaligny, 75571 Paris Cedex 12, France
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21
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Fanani ML, Maggio B. Surface pressure-dependent cross-modulation of sphingomyelinase and phospholipase A2 in monolayers. Lipids 1998; 33:1079-87. [PMID: 9870902 DOI: 10.1007/s11745-998-0308-5] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
We investigated the ways in which phospholipase A2 and sphingomyelinase are mutually modulated at lipid interfaces. The activity of one enzyme is affected by its own reaction products and by substrates and products of the other enzyme; all this depends differently on the lateral surface pressure. Ceramide inhibits both the sphingomyelinase activity rate and the extent of degradation, and decreases the lag time at all surface pressures. Dilauroyl- and dipalmitoylphosphatidylcholine, the substrates of phospholipase A2 (PLA2), do not affect sphingomyelinase activity. The products of PLA2, palmitic acid and lysopalmitoylphosphatidylcholine, strongly enhance and shift to high surface pressures the activity optimum and the cutoff point of sphingomyelinase. Palmitic acid also shifts to high surface pressures the cut-off point of PLA2 activity. Sphingomyelin strongly inhibits PLA2 at surface pressures above 5 mN/m, while ceramide shifts the cut-off point and the activity optimum to high surface pressures. The sphingolipids increase the lag time of PLA2 at low surface pressures. Both phosphohydrolytic pathways involve different levels of control on precatalytic steps and on the rate of activity that appear independent on specific alterations of molecular packing and surface potential. The mutual lipid-mediated interfacial modulation between both phosphohydrolytic pathways indicates that phospholipid degradation may be self-amplified or dampened depending on subtle changes of surface pressure and composition.
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Affiliation(s)
- M L Fanani
- Departamento de Química Biológica - CIQUIBIC, Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, Argentina
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22
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McDonough PM, Yasui K, Betto R, Salviati G, Glembotski CC, Palade PT, Sabbadini RA. Control of cardiac Ca2+ levels. Inhibitory actions of sphingosine on Ca2+ transients and L-type Ca2+ channel conductance. Circ Res 1994; 75:981-9. [PMID: 7955152 DOI: 10.1161/01.res.75.6.981] [Citation(s) in RCA: 65] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
The naturally occurring second messenger sphingosine (SPH) was examined for its ability to influence cardiac myocyte Ca2+ regulation. SPH inhibited intracellular Ca2+ transients in adult and neonatal rat ventricular myocytes. The inhibition was steeply dose dependent, with complete blockage of the Ca2+ transients occurring in the 20- to 25-mumol/L range. Whole-cell patch clamping revealed substantial inhibition of the L-type Ca2+ channel current (ICa) by SPH. The ability of SPH to block both the Ca2+ transients and ICa was not dependent on protein kinases, since the general protein kinase inhibitor H7 failed to prevent the actions of SPH. The specificity of the effect of SPH was determined in experiments showing that SPH analogues did not produce comparable effects. Neither the naturally occurring ceramide, N-stearoyl SPH, nor the cell-permeant ceramide, N-acetyl SPH, had SPH-like actions on the Ca2+ transients or L-type channel conductances. Caffeine-induced Ca2+ transients were also inhibited by the actions of SPH on cardiac sarcoplamic reticulum Ca2+ release, and the threshold for caffeine-induced Ca2+ release was raised. We conclude that SPH inhibits excitation-contraction coupling in cardiac myocytes by reducing the amount of entering "trigger Ca2+" for Ca(2+)-induced Ca2+ release and by simultaneously raising the threshold of the ryanodine receptor for Ca(2+)-induced Ca2+ release. Consequently, we propose that sphingolipids produced by the sphingomyelin signal transduction pathway could be physiologically relevant regulators of cardiac [Ca2+]i and therefore cardiac contractility.
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Affiliation(s)
- P M McDonough
- Department of Biology, San Diego State University, CA 92182
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23
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Katoh N. Induction by melittin of protein phosphorylation in bovine mammary gland and suppression of the phosphorylation by phosphatidylserine. Toxicology 1994; 94:119-29. [PMID: 7801316 DOI: 10.1016/0300-483x(94)90032-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
The protein kinase C (PKC) inhibitor sphingosine induces phosphorylation of an 18-kDa protein in Jurkat T cells and of a 19-kDa protein in bovine mammary gland, and suppresses phosphorylation of substrate proteins for PKC. Melittin, a toxic amphiphilic peptide from bee venom known to inhibit PKC activity, was examined to determine whether it, like sphingosine, induced phosphorylation of the 19-kDa protein. Melittin inhibited PKC activity in both cytosolic and total particulate fractions of bovine mammary gland, with IC50 values (concentrations causing 50% inhibition) of 5-7 microM. Melittin suppressed phosphorylation of such PKC substrate proteins as a 91-kDa protein in cytosol and a 36-kDa protein in the particulate fraction. Besides the suppression, melittin induced phosphorylation of cytosolic 105-kDa, 94-kDa, 27-kDa, 24-kDa and 19-kDa and particulate 110-kDa, 53-kDa and 43-kDa proteins, which were not clearly observed in the absence of melittin. The induction could be detected at a 10 microM concentration. Phosphorylation of these proteins was reversed by excess addition of the PKC cofactor phosphatidylserine, but not by other cofactors such as 1-oleoyl-2-acetyl-sn-glycerol or Ca2+. PKC inhibitors other than melittin [1-(5-isoquinolinylsulfonyl)-2-methyl-piperazine, gossypol, palmitoylcarnitine and adriamycin] had little effect on the induction, except at a high concentration (500 microM) of adriamycin. These results suggest that melittin, like sphingosine, has both suppressive and stimulatory effects on protein phosphorylation in bovine mammary gland.
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Affiliation(s)
- N Katoh
- National Institute of Animal Health, Hokkaido Branch Laboratory, Sapporo, Japan
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24
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Kondo T, Kakiuchi T, Senda M. Hydrolytic activity of phospholipase D from plants and Streptomyces spp. against phosphatidylcholine monolayers at the polarized oil/water interface. ACTA ACUST UNITED AC 1994. [DOI: 10.1016/0302-4598(94)80021-9] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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25
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Kõiv A, Kinnunen PK. Binding of DNA to liposomes containing different derivatives of sphingosine. Chem Phys Lipids 1994; 72:77-86. [PMID: 7923481 DOI: 10.1016/0009-3084(94)90018-3] [Citation(s) in RCA: 26] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Binding of DNA to dimyristoylphosphatidylcholine (DMPC) liposomes containing different sphingosine derivatives was investigated. DNA labelled with adriamycin was used as a fluorescence quencher and its membrane association was observed by resonance energy transfer from liposomes incorporating a pyrene-derivatized lipid bisPDPC as a donor and containing 19 mol% of sphingosine, dihydro-, phyto- or dimethylsphingosine. As revealed by differential scanning calorimetry, the thermal phase behaviour of multilamellar liposomes containing these sphingolipids was also significantly altered by DNA. Attachment of DNA to liposomes containing sphingosylphosphorylcholine was much weaker, and no binding of DNA to membranes containing N-acetylsphingosine, N-stearoylsphingosine or sphingomyelin was observed. The membrane binding of DNA was dependent on pH and could be reversed by the inclusion of phosphatidic acid (eggPA) into the liposomes. Analogously, the association of cytochrome c with eggPA could be reversed by the DNA-binding sphingosines. These findings lend support to our previous proposal that the DNA-sphingosine interaction is electrostatic and requires the presence of a positive charge in the latter. Accordingly, sphingosines carrying a protonated amino group attach DNA to membranes, while blocking of the amino group by N-acylation abolishes this interaction.
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Affiliation(s)
- A Kõiv
- Department of Medical Chemistry, University of Helsinki, Finland
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26
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Perillo MA, Guidotti A, Costa E, Yu RK, Maggio B. Modulation of phospholipases A2 and C activities against dilauroylphosphorylcholine in mixed monolayers with semisynthetic derivatives of ganglioside and sphingosine. Mol Membr Biol 1994; 11:119-26. [PMID: 7920864 DOI: 10.3109/09687689409162229] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Most of the semisynthetic ganglioside and sphingosine derivatives studied here decreased the rate as well as the extent of hydrolysis of monomolecular layers of dilauroylphosphorylcholine (dlPC) by both phospholipase A2 (PLA2) and C (PLC). For PLA2, the rate of enzymatic activity was inversely correlated (p < 0.001) with the duration of the latency period of the enzymatic reaction. The correlation between the rate of activity and the latency period was not statistically significant for PLC. The potency to inhibit PLA2 and PLC was not significantly correlated with the presence of specific chemical groups. Also, the inhibitory effect is not correlated to changes of the substrate intermolecular spacing or surface potential caused by the sphingolipids (SLs). Conversely, for PLA2 the variation of the kinetic parameters of the reaction with the molecular polarization vector of the SLs are statistically significant (p < 0.01). The rate of phospholipid degradation by PLA2 decreased, and the lag times tended to become longer, with increasing values of the SLs' polarization vector. The kinetic parameters of the reaction with PLC did not show statistically significant correlation with the polarization vector of the SLs. Our results suggest that the configuration of the electrostatic field across the interface is more important than are formal charges or specific chemical moieties in modulating the activity of PLA2. Inhibition of phospholipase activities of these types by specific SLs or their metabolites may be important as supramolecular regulatory steps at the membrane level of the amplification of lipid-mediated signaling pathways.
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Affiliation(s)
- M A Perillo
- Department of Biochemistry and Molecular Biophysics, Medical College of Virginia, Virginia Commonwealth University, Richmond 23298-0614
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27
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Cell-permeable ceramides inhibit the stimulation of DNA synthesis and phospholipase D activity by phosphatidate and lysophosphatidate in rat fibroblasts. J Biol Chem 1994. [DOI: 10.1016/s0021-9258(17)37058-8] [Citation(s) in RCA: 148] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
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