title: Lipid body formation during maturation of human mast cells.
abstract: Lipid droplets, also called lipid bodies (LB) in inflammatory cells, are important cytoplasmic organelles. However, little is known about the molecular characteristics and functions of LBs in human mast cells (MC). Here, we have analyzed the genesis and components of LBs during differentiation of human peripheral blood-derived CD34(+) progenitors into connective tissue-type MCs. In our serum-free culture system, the maturing MCs, derived from 18 different donors, invariably developed triacylglycerol (TG)-rich LBs. Not known heretofore, the MCs transcribe the genes for perilipins (PLIN)1-4, but not PLIN5, and PLIN2 and PLIN3 display different degrees of LB association. Upon MC activation and ensuing degranulation, the LBs were not cosecreted with the cytoplasmic secretory granules. Exogenous arachidonic acid (AA) enhanced LB genesis in Triacsin C-sensitive fashion, and it was found to be preferentially incorporated into the TGs of LBs. The large TG-associated pool of AA in LBs likely is a major precursor for eicosanoid production by MCs. In summary, we demonstrate that cultured human MCs derived from CD34(+) progenitors in peripheral blood provide a new tool to study regulatory mechanisms involving LB functions, with particular emphasis on AA metabolism, eicosanoid biosynthesis, and subsequent release of proinflammatory lipid mediators from these cells.
authors.affiliation: Wihuri Research Institute, 00140 Helsinki, Finland.
authors.forename: Andrea
authors.initials: A
authors.lastname: Dichlberger
authors.affiliation: Wihuri Research Institute, 00140 Helsinki, Finland.
authors.forename: Stefanie
authors.initials: S
authors.lastname: Schlager
authors.affiliation: Wihuri Research Institute, 00140 Helsinki, Finland.
authors.forename: Jani
authors.initials: J
authors.lastname: Lappalainen
authors.affiliation: Department of Biosciences, FIN-00014 University of Helsinki, Finland and.
authors.forename: Reijo
authors.initials: R
authors.lastname: Käkelä
authors.affiliation: Institute of Biotechnology, FIN-00014 University of Helsinki, Finland; and.
authors.forename: Katarina
authors.initials: K
authors.lastname: Hattula
authors.affiliation: Institute of Biotechnology, FIN-00014 University of Helsinki, Finland; and.
authors.forename: Sarah J
authors.initials: SJ
authors.lastname: Butcher
authors.affiliation: Department of Medical Biochemistry, Medical University Vienna, 1030 Vienna, Austria. Electronic address: wolfgang.schneider@meduniwien.ac.at.
authors.forename: Wolfgang J
authors.initials: WJ
authors.lastname: Schneider
authors.affiliation: Wihuri Research Institute, 00140 Helsinki, Finland. Electronic address: petri.kovanen@wri.fi.
authors.forename: Petri T
authors.initials: PT
authors.lastname: Kovanen
mesh_terms: D018952:Antigens, CD34 / Q000378:metabolism; D001095:Arachidonic Acids / Q000494:pharmacology; D015550:Cell Degranulation / Q000187:drug effects; D002454:Cell Differentiation / Q000187:drug effects; D003593:Cytoplasm / Q000187:drug effects / Q000378:metabolism; D005786:Gene Expression Regulation / Q000187:drug effects; D006801:Humans; D050356:Lipid Metabolism / Q000187:drug effects; D008055:Lipids / Q000737:chemistry*; D008407:Mast Cells / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D008565:Membrane Proteins / Q000235:genetics; D000070780:Perilipin-2; D000070796:Perilipin-3; D013234:Stem Cells / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D014280:Triglycerides / Q000378:metabolism; D033921:Vesicular Transport Proteins / Q000235:genetics
chemical_list: D018952:Antigens, CD34; D001095:Arachidonic Acids; D008055:Lipids; D008565:Membrane Proteins; C000602982:PLIN2 protein, human; C038196:PLIN3 protein, human; D000070780:Perilipin-2; D000070796:Perilipin-3; D014280:Triglycerides; D033921:Vesicular Transport Proteins