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Phospholipases play multiple cellular roles including growth, stress tolerance, sexual development, and virulence in fungi. Microbiol Res 2018; 209:55-69. [DOI: 10.1016/j.micres.2017.12.012] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2017] [Revised: 12/21/2017] [Accepted: 12/31/2017] [Indexed: 12/16/2022]
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2
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Osipov AV, Utkin YN. Antiproliferative Effects of Snake Venom Phospholipases A2 and Their Perspectives for Cancer Treatment. TOXINS AND DRUG DISCOVERY 2017. [DOI: 10.1007/978-94-007-6452-1_13] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
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3
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Chronic inhibition of brain phospholipase A2 in adult rats impairs the survival of newborn mature neurons in the hippocampus. J Neural Transm (Vienna) 2014; 122:619-28. [PMID: 25160937 DOI: 10.1007/s00702-014-1305-0] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2014] [Accepted: 08/22/2014] [Indexed: 01/03/2023]
Abstract
Adult neurogenesis occurs in the hippocampal dentate gyrus (DG) and lateral ventricles, and includes cell proliferation and neuronal differentiation, maturation and survival. In vitro studies suggest a role for phospholipase A2 (PLA2) in neuronal differentiation/maturation and survival. This study aimed to investigate the effect of in vivo chronic inhibition of brain PLA2 in adult rats on the number of newborn mature neurons in the DG. Male Wistar rats were injected with BrdU (cell proliferation marker) and 2 weeks later (beginning of neuronal maturation) sham-operated or infused intracerebroventricularly with either vehicle (DMSO in saline) or PLA2 inhibitor (MAFP dissolved in the vehicle) for 14 days via osmotic minipump. The animals were euthanised 28 days post-BrdU and their brains immunostained for BrdU and BrdU plus NeuN (mature neuronal marker) for analysis of surviving cells. MAFP reduced the number of BrdU(+) cells in the ventral DG (p < 0.05 vs. sham; p < 0.01 vs. DMSO) and the number of BrdU(+)NeuN(+) cells in the ventral (p < 0.01 vs. sham and DMSO) and whole DG (p < 0.02 vs. sham and DMSO). There was no effect of MAFP in the dorsal DG. These findings show that chronic PLA2 inhibition in adult rat hippocampus decreases the number of newborn mature neurons in the ventral DG (reflecting in the whole DG), perhaps by impairing neuronal maturation and survival, and suggest that PLA2 inhibition reported in the hippocampus of Alzheimer disease subjects might partly contribute to the neurogenic abnormalities found in the DG in this disease.
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Bacha AB. Anti-bactericidal properties of stingray Dasyatis pastinaca groups V, IIA, and IB phospholipases A2: a comparative study. Appl Biochem Biotechnol 2014; 174:1520-1534. [PMID: 25119545 DOI: 10.1007/s12010-014-1069-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2013] [Accepted: 07/21/2014] [Indexed: 11/25/2022]
Abstract
Group IIA secreted phospholipase A2 (group IIA sPLA2) is known to display potent Gram-positive bactericidal activity in vitro and in vivo. We have analyzed the bactericidal activity of the full set of native stingray and dromedary groups V, IIA, and IB sPLA2s on several Gram-positive and Gram-negative strains. The rank order potency among both marine and mammal sPLA2s against Gram-positive bacteria is group IIA > V > IB, whereas Gram-negative bacteria exhibited a much higher resistance. There is a synergic action of the sPLA2 with lysozyme when added to the bacteria culture prior to sPLA2.The bactericidal efficiency of groups V and IIA sPLA2s was shown to be dependent upon the presence of calcium ions and to a less extent Mg(2+) ions and then a correlation could be made to its hydrolytic activity of membrane phospholipids. Importantly, we showed that stingray and dromedary groups V, IIA, and IB sPLA2s present no cytotoxicity after their incubation with MDA-MB-231cells. stingray groups V and IIA sPLA2s, like mammal ones, may be considered as future therapeutic agents against bacterial infections.
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Affiliation(s)
- Abir Ben Bacha
- Biochemistry Department, Science College, King Saud University, P.O Box 22452, Riyadh, 11495, Saudi Arabia. .,Laboratory of Plant Biotechnology Applied to Crop Improvement, Faculty of Science of Sfax, University of Sfax, Sfax, 3038, Tunisia.
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Mabashi Y, Kikuma T, Maruyama JI, Arioka M, Kitamoto K. Development of a Versatile Expression Plasmid Construction System forAspergillus oryzaeand Its Application to Visualization of Mitochondria. Biosci Biotechnol Biochem 2014; 70:1882-9. [PMID: 16880596 DOI: 10.1271/bbb.60052] [Citation(s) in RCA: 60] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
We report here a development of the MultiSite Gateway(TM)-based versatile plasmid construction system applicable for the rapid and efficient preparation of Aspergillus oryzae expression plasmids. This system allows the simultaneous connection of the three DNA fragments inserted in entry clones along with a destination vector in a defined order and orientation. We prepared a variety of entry clones and destination vectors containing promoters, genes encoding carrier-proteins and fusion tags, and selectable markers, which makes it possible to generate 80 expression plasmids for each target protein. Using this system, plasmids for expression of the EGFP fused with the mitochondrial-targeting signal of citrate synthase (AoCit1) were generated. Tubular structures of mitochondria were visualized in the transformants expressing the AoCit1-EGFP fusion protein. This plasmid construction system allows us to prepare a large number of expression plasmids without laborious DNA manipulations, which would facilitate molecular biological studies on A. oryzae.
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Affiliation(s)
- Yuka Mabashi
- Department of Biotechnology, The University of Tokyo, Japan
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Ee SM, Lo YL, Shui G, Wenk MR, Shin EJ, Kim HC, Ong WY. Distribution of secretory phospholipase A2 XIIA in the brain and its role in lipid metabolism and cognition. Mol Neurobiol 2014; 50:60-75. [PMID: 24464264 DOI: 10.1007/s12035-014-8635-7] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2013] [Accepted: 01/02/2014] [Indexed: 01/03/2023]
Abstract
Phospholipases A(2) (PLA(2)) catalyze the hydrolysis of membrane phospholipids to produce free fatty acids and lysophospholipids, which have important functions in cell signaling. The present study elucidated differential expression of PLA(2) isoforms in the rat cortex by quantitative reverse transcription PCR and demonstrated that sPLA(2)-XIIA had greater messenger RNA expression than iPLA(2)-VI or cPLA(2)-IVA in different brain regions, or compared to other sPLA(2) isoforms in the prefrontal cortex (PFC) and hippocampus. Western blots identified a 24-kDa band in different regions of the adult brain, and high levels of sPLA(2)-XIIA protein expression were detected in the PFC, striatum, and thalamus. Electron microscopy showed that sPLA(2)-XIIA is present in axon terminals and dendrites. Injection of antisense oligonucleotide to sPLA(2)-XIIA in the PFC and lipidomic analysis showed increase in phospholipid but decrease in lysophospholipid species consistent with decreased catalytic activity of the enzyme, changes in arachidonic acid release, and alterations in sphingolipids. sPLA(2)-XIIA knockdown also resulted in shorter latency timings in the passive avoidance test, and higher number of errors in the attention set-shifting task, indicating deficits in working memory and attention. Together, the results show an important role of sPLA(2)-XIIA in lipid metabolism, prefrontal cortical function, and cognition.
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Affiliation(s)
- Sze-Min Ee
- Department of Anatomy, National University of Singapore, Singapore, 119260, Singapore
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7
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Nardicchi V, Ferrini M, Pilolli F, Angeli EB, Persichetti E, Beccari T, Mannucci R, Arcuri C, Donato R, Dorman RV, Goracci G. NGF Induces the Expression of Group IIA Secretory Phospholipase A2 in PC12 Cells: The Newly Synthesized Enzyme Is Addressed to Growing Neurites. Mol Neurobiol 2014; 50:15-25. [DOI: 10.1007/s12035-013-8621-5] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2013] [Accepted: 12/15/2013] [Indexed: 12/31/2022]
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Wuhanqimuge, Itakura A, Matsuki Y, Tanaka M, Arioka M. Lysophosphatidylcholine enhances NGF-induced MAPK and Akt signals through the extracellular domain of TrkA in PC12 cells. FEBS Open Bio 2013; 3:243-51. [PMID: 23772401 PMCID: PMC3678299 DOI: 10.1016/j.fob.2013.05.003] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2013] [Revised: 05/16/2013] [Accepted: 05/22/2013] [Indexed: 12/20/2022] Open
Abstract
Lysophosphatidylcholine (LPC) is one of the major lysophospholipids mainly generated by phospholipase A2 (PLA2)-mediated hydrolysis of phosphatidylcholine (PC). We previously found that LPC displays neurotrophin-like activity in the rat pheochromocytoma PC12 cells and in cerebellar granule neurons, but the molecular mechanism remains unclear. We report here that LPC specifically enhances nerve growth factor (NGF)-induced signals in PC12 cells. When PC12 cells were treated with NGF, MAPK was phosphorylated, but this phosphorylation was significantly elevated when LPC was added together. In accordance, NGF-induced expression of immediate early genes, c-fos and NGF-IA, was upregulated by LPC. Phosphorylation of the upstream components, MEK and NGF receptor TrkA, was also promoted by LPC, which was in line with increased phosphorylation of Akt. In contrast, LPC did not enhance epidermal growth factor (EGF)-, basic fibroblast growth factor-, or insulin-like growth factor-1-induced signals. Studies using TrkA/EGF receptor chimeras demonstrated that the extracellular domain, but not the transmembrane or intracellular domains, of TrkA is responsible for the effect of LPC. Exogenously-added secretory PLA2 (sPLA2) enhanced NGF-induced MAPK phosphorylation at a comparable level to LPC, suggesting that LPC generated in situ by sPLA2-mediated hydrolysis of membrane PC stimulated NGF-TrkA signal. Taken together, these results indicate a specific role and function of LPC on NGF-TrkA signaling pathway. LPC potentiates NGF-induced MAPK and Akt phosphorylation in PC12 cells. LPC enhances NGF-induced MEK and TrkA phosphorylation. LPC does not affect the signals of EGF, FGF, and IGF-1. The effect of LPC requires the extracellular domain of TrkA. sPLA2 also potentiates NGF-induced MAPK phosphorylation.
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Key Words
- Akt
- BDNF, brain-derived neurotrophic factor
- CGNs, cerebellar granule neurons
- DMEM, Dulbecco’s modified Eagle’s medium
- EGF, epidermal growth factor
- EGFP, enhanced green fluorescent protein
- EGFR, EGF receptor
- GPCR, G protein-coupled receptors
- IGF-1, insulin-like growth factor-1
- LPA, lysophosphatidic acid
- LPC, lysophosphatidylcholine
- LPE, lysophosphatidylethanolamine
- LPS, lysophosphatidylserine
- Lysophosphatidylcholine
- MAPK, mitogen-activated protein kinase
- MEK, mitogen-activated protein kinase kinase
- Mitogen-activated protein kinase (MAPK)
- NGF, nerve growth factor
- Nerve growth factor
- PC, phosphatidylcholine
- PI3K, phosphatidylinositol 3-kinase
- PLA2, phospholipase A2
- RT-PCR, reverse transcription-polymerase chain reaction
- SDS, sodium dodecyl sulfate
- TTBS, Tris-buffered saline containing 0.01% Tween 20
- TrkA
- bFGF, basic fibroblast growth factor
- sPLA2, secretory PLA2
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Affiliation(s)
- Wuhanqimuge
- Department of Biotechnology, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan
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Nevalainen TJ, Morgado I, Cardoso JCR. Identification of novel phospholipase A2 group IX members in metazoans. Biochimie 2013; 95:1534-43. [PMID: 23603114 DOI: 10.1016/j.biochi.2013.04.003] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2012] [Accepted: 04/08/2013] [Indexed: 01/19/2023]
Abstract
Sequence homologues of the bacterium Streptomyces violaceoruber and sea anemone Nematostella vectensis PLA2 pfam09056 members were identified in several bacteria, fungi and metazoans illustrating the evolution of this PLA2 sub-family. Comparison of their molecular structures revealed that bacteria and fungi members are part of the GXIV of PLA2s while metazoan representatives are similar with GIX PLA2 of the marine snail Conus magus. Members of GXIV and GIX PLA2s show modest overall sequence similarity (21-35%) but considerable motif conservation within the putative Ca(2+)-binding, catalytic sites and cysteine residue positions which are essential for enzyme function. GXIV PLA2s of bacteria and fungi typically contain four cysteine residues composing two intramolecular disulphide bonds. GIX PLA2 homologues were identified in cnidarians and molluscs and in a single tunicate but appear to be absent from other metazoan genomes. The mature GIX PLA2 deduced peptides contain up to ten cysteine residues capable of forming five putative disulphide bonds. Three disulphide bonds were identified in GIX PLA2s, two of which correspond to those localized in GXIV PLA2s. Phylogenetic analysis demonstrates that metazoan GIX PLA2s cluster separate from the bacterial and fungal GXIV PLA2s and both pfam09056 members form a group separate from the prokaryote and eukaryote GXIIA PLA2 pfam06951. Duplicate PLA2 pfam09056 genes were identified in the genomes of sea anemone N. vectensis and oyster Crassostrea gigas suggest that members of this family evolved via species-specific duplication events. These observations indicate that the newly identified metazoan pfam09056 members may be classified as GIX PLA2s and support the idea of the common evolutionary origin of GXIV and GIX PLA2 pfam09056 members, which emerged early in bacteria and were maintained in the genomes of fungi and selected extant metazoan taxa.
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Affiliation(s)
- Timo J Nevalainen
- Department of Pathology, University of Turku, Kiinamyllynkatu 10, Turku, Finland.
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Cavazzini D, Meschi F, Corsini R, Bolchi A, Rossi GL, Einsle O, Ottonello S. Autoproteolytic Activation of a Symbiosis-regulated Truffle Phospholipase A2. J Biol Chem 2012. [PMID: 23192346 DOI: 10.1074/jbc.m112.384156] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Fungal phospholipases are members of the fungal/bacterial group XIV secreted phospholipases A(2) (sPLA(2)s). TbSP1, the sPLA(2) primarily addressed in this study, is up-regulated by nutrient deprivation and is preferentially expressed in the symbiotic stage of the ectomycorrhizal fungus Tuber borchii. A peculiar feature of this phospholipase and of its ortholog from the black truffle Tuber melanosporum is the presence of a 54-amino acid sequence of unknown functional significance, interposed between the signal peptide and the start of the conserved catalytic core of the enzyme. X-ray diffraction analysis of a recombinant TbSP1 form corresponding to the secreted protein previously identified in T. borchii mycelia revealed a structure comprising the five α-helices that form the phospholipase catalytic module but lacking the N-terminal 54 amino acids. This finding led to a series of functional studies that showed that TbSP1, as well as its T. melanosporum ortholog, is a self-processing pro-phospholipase A(2), whose phospholipase activity increases up to 80-fold following autoproteolytic removal of the N-terminal peptide. Proteolytic cleavage occurs within a serine-rich, intrinsically flexible region of TbSP1, does not involve the phospholipase active site, and proceeds via an intermolecular mechanism. Autoproteolytic activation, which also takes place at the surface of nutrient-starved, sPLA(2) overexpressing hyphae, may strengthen and further control the effects of phospholipase up-regulation in response to nutrient deprivation, also in the context of symbiosis establishment and mycorrhiza formation.
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Affiliation(s)
- Davide Cavazzini
- Laboratory of Functional Genomics and Protein Engineering, Biochemistry and Molecular Biology Unit, Department of Biosciences, University of Parma, Parco Area delle Scienze 23/A, I-43124 Parma, Italy
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11
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Köstel AS, Bora-Tatar G, Erdem-Yurter H. Spinal muscular atrophy: An oxidative stress response counteracted with curcumin. ACTA ACUST UNITED AC 2012. [DOI: 10.1016/j.biomag.2012.03.007] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
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Ferrini M, Nardicchi V, Mannucci R, Arcuri C, Nicoletti I, Donato R, Goracci G. Effect of NGF on the subcellular localization of group IIA secretory phospholipase A(2) (GIIA) in PC12 cells: role in neuritogenesis. Neurochem Res 2010; 35:2168-74. [PMID: 21125328 DOI: 10.1007/s11064-010-0345-6] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/08/2010] [Indexed: 01/01/2023]
Abstract
Phospholipases A(2) (PLA(2)s) are involved in neuritogenesis but the identity of the isoforms(s) contributing to this process is still not defined. Several reports have focused on secretory PLA(2)s (sPLA(2)) as the administration of exogenous sPLA(2)s to PC12 neuronal cells stimulates neurite outgrowth. The present study demonstrates that the endogenous group IIA sPLA(2) (GIIA), constitutively expressed in mammalian neural cells, changes its subcellular localization when PC12 cells are induced to differentiate by NGF treatment. Indeed, confocal analysis showed a time-dependent accumulation of GIIA in growth cones and neurite tips. Under identical conditions the subcellular distribution of another isoform (GV) was unaffected by NGF. Contrary to GX, another sPLA(2) isoform expressed by PC12 cells, the contribution of GIIA to neuritogenesis does not require its release in the extracellular medium.
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Affiliation(s)
- M Ferrini
- Departments of Experimental Medicine and Biochemical Sciences, University of Perugia, Via del Giochetto, 06126 Perugia, Italy
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Kouchesfahani HM, Nabiuni M, Parivar K, Ebrahimi S. Effect of honey bee venom on differentiation of cholinergic neurons. JOURNAL OF VENOM RESEARCH 2010; 1:29-36. [PMID: 21544179 PMCID: PMC3086194] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/26/2010] [Revised: 08/31/2010] [Accepted: 09/02/2010] [Indexed: 11/09/2022]
Abstract
Mouse P19 embryonic carcinoma (EC) cells are pluripotent and can differentiate into a population consisting largely of neurons and glia cells using a concentration of 5x10(-7)M of retinoic acid (RA). Thus, P19 EC cells are a good model system to study events occurring during the critical phases of neuronal differentiation, in vitro. Honey bee venom (BV) consists of mellitin, phospholipase A2, apamin and several other bioactive substances. Previous studies have shown that mellitin and phospholipase A2 - two major components of BV - play an important role in the differentiation of neurons. The purpose of this study was to examine effects of BV and RA on the differentiation of cholinergic neuron in P19 cell line. Preliminary results obtained from morphological examination showed that six days after treatment with 5x10(-7)M RA, P19 cells produced processes, and gradually obtained neuronal phenotype at approximately day-10. All cells then died at day-11. P19 cells treated with 1.3μg/ml BV produced processes on day-6 and neurons appeared in the next four days. They then proceeded to total size until day-10 and produced elongated processes; however, all cells died on day-11. Using BV and RA together had the same effect but more pronounced differentiating results. It can be concluded that applying BV with RA has an additive effect on cell differentiation and proliferation. The presence of acetylcholinesterase (AChE), frequently used as a marker for neuronal differentiation, was also determined and found using DTNB.
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Affiliation(s)
- Homa Mohseni Kouchesfahani
- Department of Biology, Divison of Cell and Developmental Biology, Faculty of Sciences, University of Tarbiat Moalem, Tehran, Iran
| | - Mohammad Nabiuni
- Department of Biology, Divison of Cell and Developmental Biology, Faculty of Sciences, University of Tarbiat Moalem, Tehran, Iran,Correspondence to: Mohammad Nabiuni, , Tel: +98 9126609337, Fax: +98 261451005
| | - Kazem Parivar
- Department of Biology, Divison of Cell and Developmental Biology, Faculty of Sciences, University of Tarbiat Moalem, Tehran, Iran
| | - Somayeh Ebrahimi
- Department of Biology, Divison of Cell and Developmental Biology, Faculty of Sciences, University of Tarbiat Moalem, Tehran, Iran
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Shridas P, Bailey WM, Boyanovsky BB, Oslund RC, Gelb MH, Webb NR. Group X secretory phospholipase A2 regulates the expression of steroidogenic acute regulatory protein (StAR) in mouse adrenal glands. J Biol Chem 2010; 285:20031-9. [PMID: 20421306 DOI: 10.1074/jbc.m109.090423] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
We developed C57BL/6 mice with targeted deletion of group X secretory phospholipase A(2) (GX KO). These mice have approximately 80% higher plasma corticosterone concentrations compared with wild-type (WT) mice under both basal and adrenocorticotropic hormone (ACTH)-induced stress conditions. This increased corticosterone level was not associated with increased circulating ACTH or a defect in the hypothalamic-pituitary axis as evidenced by a normal response to dexamethasone challenge. Primary cultures of adrenal cells from GX KO mice exhibited significantly increased corticosteroid secretion compared with WT cells. Conversely, overexpression of GX secretory phospholipase A(2) (sPLA(2)), but not a catalytically inactive mutant form of GX sPLA(2), significantly reduced steroid production 30-40% in Y1 mouse adrenal cell line. This effect was reversed by the sPLA(2) inhibitor, indoxam. Silencing of endogenous M-type receptor expression did not restore steroid production in GX sPLA(2)-overexpressing Y1 cells, ruling out a role for this sPLA(2) receptor in this regulatory process. Expression of steroidogenic acute regulatory protein (StAR), the rate-limiting protein in corticosteroid production, was approximately 2-fold higher in adrenal glands of GX KO mice compared with WT mice, whereas StAR expression was suppressed in Y1 cells overexpressing GX sPLA(2). Results from StAR-promoter luciferase reporter gene assays indicated that GX sPLA(2) antagonizes StAR promoter activity and liver X receptor-mediated StAR promoter activation. In summary, GX sPLA(2) is expressed in mouse adrenal glands and functions to negatively regulate corticosteroid synthesis, most likely by negatively regulating StAR expression.
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Affiliation(s)
- Preetha Shridas
- Graduate Center for Nutritional Sciences, the Cardiovascular Research Center, University of Kentucky Medical Center, Lexington, Kentucky 40536, USA
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Nakahama T, Nakanishi Y, Viscomi AR, Takaya K, Kitamoto K, Ottonello S, Arioka M. Distinct enzymatic and cellular characteristics of two secretory phospholipases A2 in the filamentous fungus Aspergillus oryzae. Fungal Genet Biol 2010; 47:318-31. [PMID: 20045482 DOI: 10.1016/j.fgb.2009.12.011] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2009] [Revised: 12/08/2009] [Accepted: 12/28/2009] [Indexed: 11/17/2022]
Abstract
Microbial secretory phospholipases A(2) (sPLA(2)s) are among the last discovered and least known members of this functionally diverse family of enzymes. We analyzed here two sPLA(2)s, named sPlaA and sPlaB, of the filamentous ascomycete Aspergillus oryzae. sPlaA and sPlaB consist of 222 and 160 amino acids, respectively, and share the conserved Cys and catalytic His-Asp residues typical of microbial sPLA(2)s. Two sPLA(2)s differ in pH optimum, Ca(2+) requirement and expression profile. The splaA mRNA was strongly upregulated in response to carbon starvation, oxidative stress and during conidiation, while splaB was constitutively expressed at low levels and was weakly upregulated by heat shock. Experiments with sPLA(2) overexpressing strains demonstrated that two enzymes produce subtly different phospholipid composition variations and also differ in their subcellular localization: sPlaA is most abundant in hyphal tips and secreted to the medium, whereas sPlaB predominantly localizes to the ER-like intracellular compartment. Both sPLA(2) overexpressing strains were defective in conidiation, which was more pronounced for sPlaB overexpressors. Although no major morphological abnormality was detected in either DeltasplaA or DeltasplaB mutants, hyphal growth of DeltasplaB, but not that of DeltasplaA, displayed increased sensitivity to H(2)O(2) treatment. These data indicate that two A. oryzae sPLA(2) enzymes display distinct, presumably non-redundant, physiological functions.
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Affiliation(s)
- Tomoyuki Nakahama
- Department of Biotechnology, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan
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Martins RD, Alves RS, Martins AMC, Barbosa PSF, Evangelista JSAM, Evangelista JJF, Ximenes RM, Toyama MH, Toyama DO, Souza AJF, Orts DJB, Marangoni S, de Menezes DB, Fonteles MC, Monteiro HSA. Purification and characterization of the biological effects of phospholipase A(2) from sea anemone Bunodosoma caissarum. Toxicon 2009; 54:413-20. [PMID: 19463845 DOI: 10.1016/j.toxicon.2009.05.005] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2009] [Revised: 04/25/2009] [Accepted: 05/11/2009] [Indexed: 10/20/2022]
Abstract
Sea anemones contain a variety of biologically active substances. Bunodosoma caissarum is a sea anemone from the Cnidaria phylum, found only in Brazilian coastal waters. The aim of the present work was to study the biological effects of PLA(2) isolated from the sea anemone B. caissarum on the isolated perfused kidney, the arteriolar mesenteric bed and on insulin secretion. Specimens of B. caissarum were collected from the São Vicente Channel on the southern coast of the State of São Paulo, Brazil. Reverse phase HPLC analysis of the crude extract of B. caissarum detected three PLA(2) proteins (named BcPLA(2)1, BcPLA(2)2 and BcPLA(2)3) found to be active in B. caissarum extracts. MALDI-TOF mass spectrometry of BcPLA(2)1 showed one main peak at 14.7 kDa. The N-terminal amino acid sequence of BcPLA(2)1 showed high amino acid sequence identity with PLA(2) group III protein isolated from the Mexican lizard (PA23 HELSU, HELSU, PA22 HELSU) and with the honey bee Apis mellifera (PLA(2) and 1POC_A). In addition, BcPLA(2)1 also showed significant overall homology to bee PLA(2). The enzymatic activity induced by native BcPLA(2)1 (20 microg/well) was reduced by chemical treatment with p-bromophenacyl bromide (p-BPB) and with morin. BcPLA(2)1 strongly induced insulin secretion in presence of high glucose concentration. In isolated kidney, the PLA(2) from B. caissarum increased the perfusion pressure, renal vascular resistance, urinary flow, glomerular filtration rate, and sodium, potassium and chloride levels of excretion. BcPLA(2)1, however, did not increase the perfusion pressure on the mesenteric vascular bed. In conclusion, PLA(2), a group III phospholipase isolated from the sea anemone B. caissarum, exerted effects on renal function and induced insulin secretion in conditions of high glucose concentration.
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Affiliation(s)
- René D Martins
- Department of Physiology and Pharmacology - Institute of Biomedicine and Clinical Research Unit - Federal University of Ceará, Fortaleza, CEP-60.420-970, Ceará, Brazil
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Ikeno Y, Cheon SH, Konno N, Nakamura A, Kitamoto K, Arioka M. Lysophosphatidylcholine protects cerebellar granule neurons from apoptotic cell death. J Neurosci Res 2009; 87:190-9. [DOI: 10.1002/jnr.21821] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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18
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Wu PF, Chang LS, Kao YL, Wang KT. Beta-Bungarotoxin induction of neurite outgrowth in NB41A3 cells. Toxicon 2008; 52:354-60. [PMID: 18619988 DOI: 10.1016/j.toxicon.2008.06.009] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2008] [Revised: 05/20/2008] [Accepted: 06/05/2008] [Indexed: 01/05/2023]
Abstract
In this study, different concentrations of beta-Bgt were used to treat cultured NB41A3 cells. Inverted phase contrast microscopy was then used 24h after treatment to observe the outgrowth of neurite. We found a clear outgrowth of neurite at beta-Bgt concentrations of 357 nM. However, using a cytotoxicity assay to study apoptosis, we found no significant difference in the rate of cell death in cell cultures treated with either 357 nM or 714 nM. Western blotting showed that after treatment with beta-Bgt, there was a notable decrease in small G protein Cdc42 and a marked increase in RhoA protein. Flow cytometry revealed that beta-Bgt did not alter the calcium influx in NB41A3 cells. The neurite outgrowth induced by beta-Bgt was not affected by extracellular EGTA, suggesting that the internalization of beta-Bgt from extracellular was independent of phospholipase. Taken together, our results suggest the beta-Bgt-induced outgrowth of neurite from NB41A3 cells may be mediated by small G proteins.
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Affiliation(s)
- Pei-Fung Wu
- Department of Kinesiology, Health and Leisure Studies, National Kaohsiung University, Kaohsiung, Taiwan.
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19
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Masuda S, Yamamoto K, Hirabayashi T, Ishikawa Y, Ishii T, Kudo I, Murakami M. Human group III secreted phospholipase A2 promotes neuronal outgrowth and survival. Biochem J 2008; 409:429-38. [PMID: 17868035 DOI: 10.1042/bj20070844] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Human sPLA2-III [group III secreted PLA2 (phospholipase A2)] is an atypical sPLA2 isoenzyme that consists of a central group III sPLA2 domain flanked by unique N- and C-terminal domains. In the present study, we found that sPLA2-III is expressed in neuronal cells, such as peripheral neuronal fibres, spinal DRG (dorsal root ganglia) neurons and cerebellar Purkinje cells. Adenoviral expression of sPLA2-III in PC12 cells (pheochromocytoma cells) or DRG explants facilitated neurite outgrowth, whereas expression of a catalytically inactive sPLA2-III mutant or use of sPLA2-III-directed siRNA (small interfering RNA) reduced NGF (nerve growth factor)-induced neuritogenesis. sPLA2-III also suppressed neuronal death induced by NGF deprivation. Lipid MS revealed that sPLA2-III overexpression increased the cellular level of lysophosphatidylcholine, a PLA2 reaction product with neuritogenic and neurotropic activities, whereas siRNA knockdown reduced the level of lysophosphatidylcholine. These observations suggest the potential contribution of sPLA2-III to neuronal differentiation and its function under certain conditions.
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Affiliation(s)
- Seiko Masuda
- Tokyo Metropolitan Institute of Medical Science, 3-18-22 Honkomagome, Bunkyo-ku, Tokyo 113-8613, Japan
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20
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Konno N, Nakamura A, Ikeno Y, Cheon SH, Kitamoto K, Arioka M. Novel neurotrophic effects of sphingosylphosphorylcholine in cerebellar granule neurons and in PC12 cells. Biochem Biophys Res Commun 2007; 364:163-8. [PMID: 17935698 DOI: 10.1016/j.bbrc.2007.09.121] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2007] [Accepted: 09/13/2007] [Indexed: 11/16/2022]
Abstract
Sphingosylphosphorylcholine (SPC) is a choline-containing naturally occurring derivative of sphingolipid involved in various biological processes. Here we show that SPC displays neurotrophic effects in cerebellar granule neurons (CGNs) and in PC12 cells. When CGNs were cultured under non-depolarizing condition, they exhibited condensed and fragmented nuclei typical of apoptotic phenotype. SPC added to the culture medium rescued cells from undergoing apoptosis. The anti-apoptotic effect of SPC was dependent on the presence of extracellular Ca2+, suggesting that Ca2+ influx occurs upon SPC treatment. In PC12 cells, SPC displayed nerve growth factor-like neuritogenic effect which was sensitive to the presence of Ca2+ channel blocker and Ca2+ withdrawal from the medium. These results suggest that SPC plays novel neurotrophic effects in the nervous system.
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Affiliation(s)
- Naoko Konno
- Department of Biotechnology, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan
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21
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Farooqui AA, Ong WY, Horrocks LA. Inhibitors of brain phospholipase A2 activity: their neuropharmacological effects and therapeutic importance for the treatment of neurologic disorders. Pharmacol Rev 2006; 58:591-620. [PMID: 16968951 DOI: 10.1124/pr.58.3.7] [Citation(s) in RCA: 236] [Impact Index Per Article: 13.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023] Open
Abstract
The phospholipase A(2) family includes secretory phospholipase A(2), cytosolic phospholipase A(2), plasmalogen-selective phospholipase A(2), and calcium-independent phospholipase A(2). It is generally thought that the release of arachidonic acid by cytosolic phospholipase A(2) is the rate-limiting step in the generation of eicosanoids and platelet activating factor. These lipid mediators play critical roles in the initiation and modulation of inflammation and oxidative stress. Neurological disorders, such as ischemia, spinal cord injury, Alzheimer's disease, multiple sclerosis, prion diseases, and epilepsy are characterized by inflammatory reactions, oxidative stress, altered phospholipid metabolism, accumulation of lipid peroxides, and increased phospholipase A(2) activity. Increased activities of phospholipases A(2) and generation of lipid mediators may be involved in oxidative stress and neuroinflammation associated with the above neurological disorders. Several phospholipase A(2) inhibitors have been recently discovered and used for the treatment of ischemia and other neurological diseases in cell culture and animal models. At this time very little is known about in vivo neurochemical effects, mechanism of action, or toxicity of phospholipase A(2) inhibitors in human or animal models of neurological disorders. In kainic acid-mediated neurotoxicity, the activities of phospholipase A(2) isoforms and their immunoreactivities are markedly increased and phospholipase A(2) inhibitors, quinacrine and chloroquine, arachidonyl trifluoromethyl ketone, bromoenol lactone, cytidine 5-diphosphoamines, and vitamin E, not only inhibit phospholipase A(2) activity and immunoreactivity but also prevent neurodegeneration, suggesting that phospholipase A(2) is involved in the neurodegenerative process. This also suggests that phospholipase A(2) inhibitors can be used as neuroprotectants and anti-inflammatory agents against neurodegenerative processes in neurodegenerative diseases.
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Affiliation(s)
- Akhlaq A Farooqui
- Department of Molecular and Cellular Biochemistry, The Ohio State University, 1645 Neil Avenue, Columbus, OH 43210-1218, USA
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22
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Köhler GA, Brenot A, Haas-Stapleton E, Agabian N, Deva R, Nigam S. Phospholipase A2 and phospholipase B activities in fungi. BIOCHIMICA ET BIOPHYSICA ACTA 2006; 1761:1391-9. [PMID: 17081801 PMCID: PMC2077850 DOI: 10.1016/j.bbalip.2006.09.011] [Citation(s) in RCA: 56] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/27/2006] [Revised: 09/20/2006] [Accepted: 09/25/2006] [Indexed: 10/24/2022]
Abstract
As saprophytes or disease causing microorganisms, fungi acquire nutrients from dead organic material or living host organisms. Lipids as structural components of cell membranes and storage compartments play an important role as energy-rich food source. In recent years, it also has become clear that lipids have a wide range of bioactive properties including signal transduction and cell to cell communication. Thus, it is not surprising that fungi possess a broad range of hydrolytic enzymes that attack neutral lipids and phospholipids. Especially during infection of a mammalian host, phospholipase A(2) (PLA(2)) enzymes released by fungi could play important roles not only for nutrient acquisition and tissue invasion, but for intricate modulation of the host's immune response. Sequencing of fungal genomes has revealed a wide range of genes encoding PLA(2) activities in fungi. We are just beginning to become aware of the significance these enzymes could have for the fungal cells and their interaction with the host.
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Affiliation(s)
- Gerwald A. Köhler
- Department of Cell and Tissue Biology, University of California, San Francisco, U.S.A
| | - Audrey Brenot
- Department of Cell and Tissue Biology, University of California, San Francisco, U.S.A
| | - Eric Haas-Stapleton
- Department of Cell and Tissue Biology, University of California, San Francisco, U.S.A
| | - Nina Agabian
- Department of Cell and Tissue Biology, University of California, San Francisco, U.S.A
| | - Rupal Deva
- Eicosanoid Research Division and Center for Experimental Gynecology & Breast Research, Charité - Univ.-Klinikum Benjamin Franklin, D-12200 Berlin, Germany
| | - Santosh Nigam
- Eicosanoid Research Division and Center for Experimental Gynecology & Breast Research, Charité - Univ.-Klinikum Benjamin Franklin, D-12200 Berlin, Germany
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23
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Putz T, Ramoner R, Gander H, Rahm A, Bartsch G, Thurnher M. Antitumor action and immune activation through cooperation of bee venom secretory phospholipase A2 and phosphatidylinositol-(3,4)-bisphosphate. Cancer Immunol Immunother 2006; 55:1374-83. [PMID: 16485125 PMCID: PMC11030777 DOI: 10.1007/s00262-006-0143-9] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2005] [Accepted: 01/27/2006] [Indexed: 10/25/2022]
Abstract
We evaluated tumor cell growth modulation by bee venom secretory phospholipase A2 (bv-sPLA2) and phosphatidylinositol-(3,4)-bisphosphate as well as potential cooperative effects. In addition, the immunomodulatory impact of tumor cell treatment was examined by monitoring changes in phenotype and function of monocyte-derived dendritic cells (moDCs) cocultured with pretreated tumor cells. Bv-sPLA2 or phosphatidylinositol-(3,4)-bisphosphate alone displayed moderate effects on the proliferation of A498 renal cell carcinoma cells, T-47D breast cancer cells, DU145 prostate cancer cells and BEAS-2B transformed lung cells. However, when bv-sPLA2 was coadministered with phosphatidylinositol-(3,4)-bisphosphate a potent inhibition of [3H] thymidine incorporation into all tested cell lines occurred. This inhibition was due to massive cell lysis that reduced the number of cells with proliferative capacity. Importantly, tumor cell lysates generated with bv-sPLA2 plus phosphatidylinositol-(3,4)-bisphosphate induced maturation of human moDCs demonstrated by enhanced expression of CD83 and improved stimulation in allogeneic mixed leukocyte reactions. Our data demonstrate that bv-sPLA2 and phosphatidylinositol-(3,4)-bisphosphate synergistically generate tumor lysates which enhance the maturation of immunostimulatory human monocyte-derived dendritic cells. Such tumor lysates which represent complex mixtures of tumor antigens and simultaneously display potent adjuvant properties meet all requirements of a tumor vaccine.
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Affiliation(s)
- Thomas Putz
- Department of Urology, University of Innsbruck, Anichstrasse 35, 6020 Innsbruck, Austria
| | - Reinhold Ramoner
- Department of Urology, University of Innsbruck, Anichstrasse 35, 6020 Innsbruck, Austria
| | - Hubert Gander
- Department of Urology, University of Innsbruck, Anichstrasse 35, 6020 Innsbruck, Austria
| | - Andrea Rahm
- Department of Urology, University of Innsbruck, Anichstrasse 35, 6020 Innsbruck, Austria
| | - Georg Bartsch
- Department of Urology, University of Innsbruck, Anichstrasse 35, 6020 Innsbruck, Austria
| | - Martin Thurnher
- Department of Urology, University of Innsbruck, Anichstrasse 35, 6020 Innsbruck, Austria
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24
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Scott GA, Arioka M, Jacobs SE. Lysophosphatidylcholine mediates melanocyte dendricity through PKCzeta activation. J Invest Dermatol 2006; 127:668-75. [PMID: 17024099 DOI: 10.1038/sj.jid.5700567] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Melanocytes photoprotect the skin through transfer of melanin-containing melanosomes to keratinocytes. Factors that increase melanocyte dendricity increase melanosome transfer, and are important for prevention of skin cancer. Secretory phospholipase-A2 type X (sPLA2-X) is released by epidermal keratinocytes and we have shown that lysophosphatidylcholine (LPC), the main lysophospholipid released in response to sPLA2-X activity, stimulates melanocyte dendricity. LPC activates protein kinase C (PKC) and increases cAMP in other cells. Treatment of melanocytes with sPLA2-X or LPC induced phosphorylation of the zeta isoform of PKC, and inhibition of protein kinase C zeta (PKCzeta) activity abrogated LPC-dependent dendricity. We have shown previously that the guanosine triphosphate-binding proteins Rac and Rho link hormone signaling and dendricity in melanocytes. Treatment of melanocytes with LPC induced rapid activation of Rac that peaked at 30 minutes; Rho was also activated, but peaked earlier and declined faster. Through the use of constitutively active mutants of Rac, we show that PKCzeta activation is downstream of Rac. We conclude that the primary signaling pathway for LPC-dependent dendrite formation in human melanocytes involves the activation of PKCzeta and that PKCzeta phosphorylation is Rac dependent. Downstream mediators of LPC-dependent dendricity include Rac and Rho.
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Affiliation(s)
- Glynis A Scott
- Department of Dermatology, University of Rochester School of Medicine, Rochester, New York 14642, USA.
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25
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Balestrieri B, Arm JP. Group V sPLA2: classical and novel functions. Biochim Biophys Acta Mol Cell Biol Lipids 2006; 1761:1280-8. [PMID: 16945583 DOI: 10.1016/j.bbalip.2006.07.008] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2006] [Revised: 07/20/2006] [Accepted: 07/25/2006] [Indexed: 10/24/2022]
Abstract
Group V sPLA(2) is unique among the family of secretory sPLA(2) enzymes in being able to bind to cell membranes through both interfacial-binding and through binding to proteoglycan. The function of group V sPLA(2) as an enzyme and its cross-talk with cPLA(2)alpha in initiating eicosanoid generation is well documented. Evidence, though, is emerging on the ability of this molecule to act as a regulator of several intracellular and extracellular pathways independently of its ability to provide arachidonic acid for eicosanoid generation, acting within the cell or as a secreted enzyme. In this article we will provide an overview of the properties of the enzyme and how they relate to our current understanding of its function.
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Affiliation(s)
- Barbara Balestrieri
- Department of Medicine, Harvard Medical School, Brigham and Women's Hospital, Boston, MA 02115, USA
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26
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Makarova YV, Osipov AV, Tsetlin VI, Utkin YN. Influence of phospholipases A2 from snake venoms on survival and neurite outgrowth in pheochromocytoma cell line PC12. BIOCHEMISTRY (MOSCOW) 2006; 71:678-84. [PMID: 16827660 DOI: 10.1134/s0006297906060125] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
To determine whether the ability to induce neurite outgrowth in rat pheochromocytoma cell line PC12 is characteristic of phospholipases of different types, we have studied the influence of phospholipase A(2) (PLA2) from cobra Naja kaouthia venom and two PLA2s from viper Vipera nikolskii venom on PC12 cells. Phospholipases from the viper venom are heterodimers in which only one of the subunits is enzymatically active, while PLA2 from the cobra venom is a monomer. It was found that all three PLA2s induce neurite outgrowth in PC12. The PLA2 from cobra venom exhibits this effect at higher concentrations as compared to the viper enzymes. We have not observed such an activity for isolated subunits of viper PLA2s, since the enzymatically active subunits have very high cytotoxicity, while the other subunits are not active at all. However, co-incubation of active and inactive subunits before addition to the cells leads to a marked decrease in cytotoxicity and to restoration of the neurite-inducing activity. It has also been shown that all enzymatically active PLA2s are cytotoxic, the PLA2 from cobra venom being the least active. Thus, for the first time we have shown that PLA2s from snake venoms can induce neurite outgrowth in PC12 cells.
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Affiliation(s)
- Ya V Makarova
- Shemyakin and Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Moscow, 117997, Russia
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27
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Scott GA, Jacobs SE, Pentland AP. sPLA2-X stimulates cutaneous melanocyte dendricity and pigmentation through a lysophosphatidylcholine-dependent mechanism. J Invest Dermatol 2006; 126:855-61. [PMID: 16456529 DOI: 10.1038/sj.jid.5700180] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Photoprotection of the skin is provided by melanocytes, neural crest derived cells that synthesize melanin in specialized organelles that are transferred to keratinocytes. Secretory phospholipases comprise a large family of Ca2+-dependent enzymes that liberate arachidonic acid (AA), a precursor of prostaglandins, as well as lysophospholipids. The predominant secretory phospholipase expressed by keratinocytes is group X secretory phospholipase A2 (sPLA2), which liberates large amounts of AA and the lysophospholipid lysophosphatidylcholine (LPC), from membrane preparations. Recent work by our laboratory has shown that melanocytes express receptors for prostaglandins that upon activation stimulate melanocyte dendricity and activity of tyrosinase, a key enzyme in melanin biosynthesis. In the present study, we have treated human melanocytes with recombinant sPLA2-X and show that low levels of sPLA2-X stimulate both tyrosinase activity and melanocyte dendricity. We found that the effects of sPLA2-X are mediated predominantly by LPC, not AA, and we have demonstrated expression of the phospholipase A2 receptor and two G-protein-coupled receptors for LPC (G2A and GPR119) in human melanocytes. Because secretory phospholipases are released during inflammation and are regulated by UV irradiation, our data suggest an important role for sPLA2-X in cutaneous pigmentation through the release of LPC.
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Affiliation(s)
- Glynis A Scott
- Department of Dermatology, University or Rochester School of Medicine and Dentistry, Rochester, New York 14642, USA.
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28
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Cai Y, Wu P, Ozen M, Yu Y, Wang J, Ittmann M, Liu M. Gene expression profiling and analysis of signaling pathways involved in priming and differentiation of human neural stem cells. Neuroscience 2006; 138:133-48. [PMID: 16414199 DOI: 10.1016/j.neuroscience.2005.11.041] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2005] [Revised: 11/08/2005] [Accepted: 11/08/2005] [Indexed: 01/02/2023]
Abstract
Human neural stem cells have the ability to differentiate into all three major cell types in the CNS including neurons, astrocytes and oligodendrocytes. The multipotency of human neural stem cells shed a light on the possibility of using stem cells as a therapeutic tool for various neurological disorders including neurodegenerative diseases and neurotrauma that involve a loss of functional neurons. We have discovered previously a priming procedure to direct primarily cultured human neural stem cells to differentiate into almost pure neurons when grafted into adult CNS. However, the molecular mechanism underlying this phenomenon is still unknown. To unravel transcriptional changes of human neural stem cells upon priming, cDNA microarray was used to study temporal changes in human neural stem cell gene expression profile during priming and differentiation. As a result, transcriptional levels of 520 annotated genes were detected changed in at least at two time points during the priming process. In addition, transcription levels of more than 3000 hypothetical protein encoding genes and EST genes were modulated during the priming and differentiation processes of human neural stem cells. We further analyzed the named genes and grouped them into 14 functional categories. Of particular interest, key cell signal transduction pathways, including the G-protein-mediated signaling pathways (heterotrimeric and small monomeric GTPase pathways), the Wnt signaling pathway and the TGF-beta pathway, are modulated by the neural stem cell priming, suggesting important roles of these key signaling pathways in priming and differentiation of human neural stem cells.
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Affiliation(s)
- Y Cai
- Alkek Institute of Biosciences and Technology, Department of Medical Biochemistry and Genetics, Texas A&M University System Health Science Center, Houston, TX 77030, USA
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29
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Marszalek JR, Lodish HF. Docosahexaenoic acid, fatty acid-interacting proteins, and neuronal function: breastmilk and fish are good for you. Annu Rev Cell Dev Biol 2006; 21:633-57. [PMID: 16212510 DOI: 10.1146/annurev.cellbio.21.122303.120624] [Citation(s) in RCA: 180] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
In contrast to other tissues, the nervous system is enriched in the polyunsaturated fatty acids (PUFAs): arachidonic acid (AA, 20:4 n-6) and docosahexaenoic acid (DHA, 22:6 n-3). Despite their abundance in the nervous system, AA and DHA cannot be synthesized de novo by mammals; they, or their precursors, must be ingested from dietary sources and transported to the brain. During late gestation and the early postnatal period, neurodevelopment is exceptionally rapid, and substantial amounts of PUFAs, especially DHA, are critical to ensure neurite outgrowth as well as proper brain and retina development. Here, we review the various functions of DHA in the nervous system, the proteins involved in its internalization and metabolism into phospholipids, and its relationship to several neurological disorders, including Alzheimer's disease and depression.
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Affiliation(s)
- Joseph R Marszalek
- Whitehead Institute for Biomedical Research, Cambridge, Massachusetts 02142, USA.
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30
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Ikeno Y, Konno N, Cheon SH, Bolchi A, Ottonello S, Kitamoto K, Arioka M. Secretory Phospholipases A2 Induce Neurite Outgrowth in PC12 Cells through Lysophosphatidylcholine Generation and Activation of G2A Receptor. J Biol Chem 2005; 280:28044-52. [PMID: 15927955 DOI: 10.1074/jbc.m503343200] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
We previously demonstrated that secretory phospholipase A2 (sPLA2) and lysophosphatidylcholine (LPC) exhibit neurotrophin-like neuritogenic activity in the rat pheochromocytoma cell line PC12. In this study, we further analyzed the mechanism whereby sPLA2 displays neurite-inducing activity. Exogenously added mammalian group X sPLA2 (sPLA2-X), but not group IB and IIA sPLA2s, induced neuritogenesis, which correlated with the ability of sPLA2-X to liberate LPC into the culture media. In accordance, blocking the effect of LPC by supplementation of bovine serum albumin or phospholipase B attenuated neuritogenesis by sPLA2 or LPC. Overproduction or suppression of G2A, a G-protein-coupled receptor involved in LPC signaling, resulted in the enhancement or reduction of neuritogenesis induced by sPLA2 treatment. These results indicate that the neuritogenic effect of sPLA2 is mediated by generation of LPC and subsequent activation of G2A.
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Affiliation(s)
- Yutaka Ikeno
- Department of Biotechnology, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan
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31
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Masuda S, Murakami M, Takanezawa Y, Aoki J, Arai H, Ishikawa Y, Ishii T, Arioka M, Kudo I. Neuronal Expression and Neuritogenic Action of Group X Secreted Phospholipase A2. J Biol Chem 2005; 280:23203-14. [PMID: 15781456 DOI: 10.1074/jbc.m500985200] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Although individual mammalian secreted phospholipase A(2) (sPLA(2)) enzymes exhibit unique tissue and cellular distributions, the cell type-specific functions of each enzyme remain largely unknown. In this study, we found by immunohistochemistry that group X sPLA(2) (sPLA(2)-X) is uniquely located in the peripheral neuronal fibers, an observation that was supported by detection of its transcript and protein in the neuronal cell line PC12 and in primary dorsal root ganglia neurons. Adenoviral expression of sPLA(2)-X in PC12 cells facilitated neurite outgrowth, particularly when combined with a suboptimal concentration of nerve growth factor. In neuronally differentiated PC12 cells, sPLA(2)-X was preferentially localized in the Golgi apparatus and growth cones, and proteolytic conversion of the proenzyme to mature enzyme mainly occurred after the secretion process. The neurite-extending ability of sPLA(2)-X depended on the production of its catalytic product, lysophosphatidylcholine. Moreover, nerve growth factor-induced neurite extension of PC12 cells was modestly but significantly attenuated by an anti-sPLA(2)-X antibody or by a small interfering RNA for sPLA(2)-X. These observations suggest the potential contribution of sPLA(2)-X to neuronal differentiation, and possibly repair, under certain conditions.
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Affiliation(s)
- Seiko Masuda
- Department of Health Chemistry, School of Pharmaceutical Sciences, Showa University, Shinagawa-ku, Tokyo, USA
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32
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Ramoner R, Putz T, Gander H, Rahm A, Bartsch G, Schaber C, Thurnher M. Dendritic-cell activation by secretory phospholipase A2. Blood 2005; 105:3583-7. [PMID: 15494434 DOI: 10.1182/blood-2004-08-3001] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
AbstractDendritic cells (DCs), also referred to as the sentinels of the immune system, induce and coordinate important functions of immune surveillance. DCs acquire immunity-initiating capacity only after a process of maturation usually induced by ligands that bind to members of the tumor necrosis factor (TNF) or toll-like receptor families. Secretory phospholipase A2 (sPLA2), which hydrolyzes the sn-2 ester bond of glycerophospholipids, regulates a variety of cellular functions including migration of endothelial cells and neurite outgrowth. In the present study we investigated the role of sPLA2 in DC biology. We report that human monocyte-derived DC cultures lack sPLA2 activity but respond to exogenous sPLA2. sPLA2 alone and in cooperation with TNF-α and interleukin 1 β (IL-1β) induced fatty acid release from DC membranes, which was accompanied by upregulation of surface markers and by an increase in the migratory and immunostimulatory capacity of the DCs. Our findings indicate that secreted enzymes such as sPLA2 can contribute to DC maturation and emphasize the role of lipid mediators in the regulation of immune responses. This observation may also have implications for DC-based vaccine development.
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Affiliation(s)
- Reinhold Ramoner
- Department of Urology and Kompetenzzentrum Medizin Tirol (KMT), Medical University of Innsbruck, Anichstrasse 35, 6020 Innsbruck, Austria
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33
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Arioka M, Cheon SH, Ikeno Y, Nakashima S, Kitamoto K. A novel neurotrophic role of secretory phospholipases A2for cerebellar granule neurons. FEBS Lett 2005; 579:2693-701. [PMID: 15862311 DOI: 10.1016/j.febslet.2005.03.092] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2005] [Revised: 03/24/2005] [Accepted: 03/25/2005] [Indexed: 10/25/2022]
Abstract
Cultured cerebellar granule neurons (CGNs) require membrane depolarization or neurotrophic factors for their survival in vitro and undergo apoptosis when deprived of these survival-promoting stimuli. Here, we show that secretory phospholipases A(2)s (sPLA(2)s) rescue CGNs from apoptosis after potassium deprivation. The neurotrophic effect required the enzymatic activity of sPLA(2)s, since catalytically inactive mutants of sPLA(2)s failed to protect CGNs from apoptosis. Consistently, the ability of sPLA(2)s to protect CGNs from apoptosis correlated with the extent of sPLA(2)-induced arachidonic acid release from live CGNs. The survival-promoting effect of sPLA(2) was inhibited by depletion of extracellular Ca(2+) or by the presence of L-type Ca(2+) channel blocker nicardipine, suggesting that Ca(2+) influx occurs upon sPLA(2) treatment. Among the mammalian sPLA(2)s tested, only group X sPLA(2), but not group IB nor IIA sPLA(2)s, displayed neurotrophic activity. These results suggest a novel, unexpected neurotrophin-like role of sPLA(2) in the nervous system.
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Affiliation(s)
- Manabu Arioka
- Department of Biotechnology, The University of Tokyo, Bunkyo-ku, Japan.
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Fuenzalida KM, Aguilera MC, Piderit DG, Ramos PC, Contador D, Quiñones V, Rigotti A, Bronfman FC, Bronfman M. Peroxisome Proliferator-activated Receptor γ Is a Novel Target of the Nerve Growth Factor Signaling Pathway in PC12 Cells. J Biol Chem 2005; 280:9604-9. [PMID: 15632188 DOI: 10.1074/jbc.m409447200] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Peroxisome proliferator-activated receptor gamma (PPARgamma), a member of the nuclear receptor superfamily, is subject to considerable interest because of its role in adipocyte differentiation, metabolic control, and anti-inflammatory action. PPARgamma research in brain cells is presently focused on glial PPARgamma because of its potential as a pharmacological target in the treatment of neurodegenerative diseases with an inflammatory component. In neurons PPARgamma function is far from clear, and PPARgamma agonist-dependent and -independent effects on cell survival or differentiation have been reported. We used PC12 cells, widely used to study neuronal signaling, such as nerve growth factor (NGF)-induced differentiation and survival or epidermal growth factor-dependent cell proliferation to dissect the possible involvement of PPARgamma in these pathways. We show that NGF but not epidermal growth factor increases the transcriptional activity of PPARgamma, and modulates the expression of this transcription factor. Because NGF signals through the tyrosine kinase (TrkA) NGF receptor and/or the p75NTR receptor, we used rescue experiments with a PC12 cell mutant lacking TrkA to show that NGF-induced PPARgamma activation is dependent on TrkA activation. Our results point out PPARgamma as a novel target of the TrkA-mediated neuronal cell survival and differentiating pathway and suggest a potential new inflammatory-independent therapeutic approach for pharmacological intervention in neurological disorders.
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Affiliation(s)
- Karen M Fuenzalida
- Centro de Regulación Celular y Patología and Millennium Institute for Fundamental and Applied Biology, Faculty of Biological Sciences, P. Universidad Católica de Chile, Casilla 114-D, Santiago, Chile
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35
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Park Y, Kim Y, Stanley D. The bacterium Xenorhabdus nematophila inhibits phospholipases A2 from insect, prokaryote, and vertebrate sources. Naturwissenschaften 2004; 91:371-3. [PMID: 15278222 DOI: 10.1007/s00114-004-0548-2] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2004] [Accepted: 06/19/2004] [Indexed: 10/26/2022]
Abstract
The bacterium, Xenorhabdus nematophila, is a virulent insect pathogen. Part of its pathogenicity is due to impairing cellular immunity by blocking biosynthesis of eicosanoids, the major recognized signal transduction system in insect cellular immunity. X. nematophila inhibits the first step in eicosanoid biosynthesis, phospholipase A(2) (PLA(2)). Here we report that the bacterium inhibits PLA(2) from two insect immune tissues, hemocytes and fat body, as well as PLA(2)s selected to represent a wide range of organisms, including prokaryotes, insects, reptiles, and mammals. Our finding on a bacterial inhibitor of PLA(2) activity contributes new insight into the chemical ecology of microbe-host interactions, which usually involve actions rather than inhibitors of PLA(2)s.
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Affiliation(s)
- Youngjin Park
- Insect Biochemical Physiology Laboratory, University of Nebraska, Lincoln, NE 68583-0816, USA
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Nakashima S, Kitamoto K, Arioka M. The catalytic activity, but not receptor binding, of sPLA2s plays a critical role for neurite outgrowth induction in PC12 cells. Brain Res 2004; 1015:207-11. [PMID: 15223389 DOI: 10.1016/j.brainres.2004.04.069] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/20/2004] [Indexed: 11/22/2022]
Abstract
We previously showed that fungal secretory phospholipase A2 (sPLA2) induces neurite formation in PC12 cells in an L-type Ca2+ channel activity-dependent manner. In this study we compared neurite-inducing activity of different sPLA2s, including bee venom sPLA2 (bvPLA2), and found that it correlated with the ability of each sPLA2 to release fatty acids from live PC12 cells. Consistently, using several mutants of bvPLA2, we found that the enzymatic activity rather than the binding activity to the putative N-type receptor for neurotoxic sPLA2s is the critical determinant for the neuritogenic response. These results imply that the neurite outgrowth is elicited by the messenger(s) produced upon degradation of membrane phospholipids.
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Affiliation(s)
- Satoru Nakashima
- Department of Biotechnology, The University of Tokyo, 1-1-1 Yayoi, Bunkyo, Tokyo 113-8657, Japan
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