title: Effects of arachidonic acid analogs on FcepsilonRI-mediated activation of mast cells.
abstract: Polyunsaturated fatty acids (PUFAs) such as arachidonic acid (AA) have been shown to modulate a number of inflammatory disorders. Mast cells play a critical role in the initiation and maintenance of inflammatory responses. However, the effects of PUFAs on mast cell functions have not been fully addressed. We here-in examined the effects of PUFAs on the high affinity IgE receptor (FcepsilonRI)-mediated mast cell activation using RBL-2H3 cells, a rat mast cell line, that were cultured in the medium containing palmitic acid (PA), AA, or the AA analogs mead acid (MA) and eicosapentaenoic acid (EPA). In AA-supplemented cells, the FcepsilonRI-mediated beta-hexosamidase and TNF-alpha release, calcium (Ca(2+)) influx, and some protein tyrosine phosphorylations including Syk and linker for activation of T cells (LAT) were enhanced, whereas, in MA- or PA-supplemented cells, they were not changed when compared with cells cultured in control medium. In EPA-supplemented cells, the enhancements of beta-hexosamidase release and protein tyrosine phosphorylations were observed. Furthermore, in AA- or EPA-supplemented cells, FcepsilonRI-mediated intracellular production of reactive oxygen species (ROS) that is required for the tyrosine phosphorylation of LAT and Ca(2+) influx were enhanced when compared with the other cells. Thus, preincubation of AA or EPA augmented FcepsilonRI-mediated degranulation in mast cells by affecting early events of FcepsilonRI signal transduction, which might be associated with the change of fatty acid composition of the cell membrane and enhanced production of ROS. The results suggest that some PUFAs can modulate FcepsilonRI-mediated mast cell activation and might affect FcepsilonRI/mast cell-mediated inflammation, such as allergic reaction.
authors.affiliation: Atopy (Allergy) Research Center, Juntendo University School of Medicine, 2-1-1, Hongo, Bunkyo-ku, Tokyo 113-8421, Japan. nbnakano@med.juntendo.ac.jp
authors.forename: Nobuhiro
authors.initials: N
authors.lastname: Nakano
authors.forename: Atsuhito
authors.initials: A
authors.lastname: Nakao
authors.forename: Takafumi
authors.initials: T
authors.lastname: Uchida
authors.forename: Norifumi
authors.initials: N
authors.lastname: Shirasaka
authors.forename: Hajime
authors.initials: H
authors.lastname: Yoshizumi
authors.forename: Ko
authors.initials: K
authors.lastname: Okumura
authors.forename: Ryoji
authors.initials: R
authors.lastname: Tsuboi
authors.forename: Hideoki
authors.initials: H
authors.lastname: Ogawa
mesh_terms: D015126:8,11,14-Eicosatrienoic Acid / Q000031:analogs & derivatives / Q000494:pharmacology; D048868:Adaptor Proteins, Signal Transducing / Q000378:metabolism; D000818:Animals; D016718:Arachidonic Acid / Q000494:pharmacology*; D002118:Calcium / Q000378:metabolism; D015550:Cell Degranulation / Q000187:drug effects; D002462:Cell Membrane / Q000187:drug effects / Q000378:metabolism; D002478:Cells, Cultured; D016207:Cytokines / Q000378:metabolism; D015118:Eicosapentaenoic Acid / Q000494:pharmacology; D005231:Fatty Acids, Unsaturated / Q000378:metabolism*; D047908:Intracellular Signaling Peptides and Proteins / Q000378:metabolism; D008407:Mast Cells / Q000187:drug effects* / Q000502:physiology*; D008565:Membrane Proteins / Q000378:metabolism; D019308:Palmitic Acid / Q000494:pharmacology; D010750:Phosphoproteins / Q000378:metabolism; D010766:Phosphorylation; D011505:Protein-Tyrosine Kinases / Q000378:metabolism; D051381:Rats; D017382:Reactive Oxygen Species / Q000378:metabolism; D017455:Receptors, IgE / Q000187:drug effects / Q000378:metabolism*; D015398:Signal Transduction; D000072377:Syk Kinase; D014443:Tyrosine / Q000378:metabolism
chemical_list: D048868:Adaptor Proteins, Signal Transducing; D016207:Cytokines; D005231:Fatty Acids, Unsaturated; D047908:Intracellular Signaling Peptides and Proteins; C491733:Lat protein, rat; D008565:Membrane Proteins; D010750:Phosphoproteins; D017382:Reactive Oxygen Species; D017455:Receptors, IgE; D016718:Arachidonic Acid; D019308:Palmitic Acid; D014443:Tyrosine; D015118:Eicosapentaenoic Acid; D011505:Protein-Tyrosine Kinases; D000072377:Syk Kinase; C000606898:Syk protein, rat; D015126:8,11,14-Eicosatrienoic Acid; C010944:mead acid; D002118:Calcium