title: Protein kinase C isoforms have differential roles in the regulation of human sebocyte biology.
abstract: Protein kinase C (PKC) isoforms have crucial roles in cutaneous signaling. Interestingly, we lack information about their involvement in human sebaceous gland biology. Therefore, in this current study, we investigated the functions of the PKC system in human immortalized SZ95 sebocytes. Using molecular biological approaches, imaging, and functional assays, we report that SZ95 sebocytes express the conventional cPKCα; the novel nPKCδ, ɛ, and η; and the atypical aPKCζ. Activation of the PKC system by phorbol 12-myristate 13-acetate (PMA) stimulated lipid synthesis (a hallmark of differentiation) and resulted in translocation and then downregulation of cPKCα and nPKCδ. In good accord with these findings, the effect of PMA was effectively abrogated by inhibitors and short interfering RNA-mediated "silencing" of cPKCα and nPKCδ. Of further importance, molecular or pharmacological inhibition of nPKCδ also prevented the lipogenic and apoptosis-promoting action of arachidonic acid. Finally, we also found that "knockdown" of the endogenous aPKCζ activity markedly increased basal lipid synthesis and apoptosis, suggesting its constitutive activity in suppressing these processes. Collectively, our findings strongly argue for the fact that certain PKCs have pivotal, isoform-specific, differential, and antagonistic roles in the regulation of human sebaceous gland-derived sebocyte biology.
authors.affiliation: DE-MTA Lendület Cellular Physiology Research Group, Department of Physiology, Research Center for Molecular Medicine, University of Debrecen, Debrecen, Hungary.
authors.forename: Tamás
authors.initials: T
authors.lastname: Géczy
authors.forename: Attila
authors.initials: A
authors.lastname: Oláh
authors.forename: Balázs I
authors.initials: BI
authors.lastname: Tóth
authors.forename: Gabriella
authors.initials: G
authors.lastname: Czifra
authors.forename: Attila G
authors.initials: AG
authors.lastname: Szöllősi
authors.forename: Tamás
authors.initials: T
authors.lastname: Szabó
authors.forename: Christos C
authors.initials: CC
authors.lastname: Zouboulis
authors.forename: Ralf
authors.initials: R
authors.lastname: Paus
authors.forename: Tamás
authors.initials: T
authors.lastname: Bíró
mesh_terms: D017209:Apoptosis; D002454:Cell Differentiation; D015536:Down-Regulation; D015971:Gene Expression Regulation, Enzymologic; D020868:Gene Silencing; D006801:Humans; D008055:Lipids / Q000737:chemistry; D009336:Necrosis; D020033:Protein Isoforms; D011493:Protein Kinase C / Q000096:biosynthesis*; D051571:Protein Kinase C-alpha / Q000096:biosynthesis*; D051745:Protein Kinase C-delta / Q000096:biosynthesis*; D051744:Protein Kinase C-epsilon / Q000096:biosynthesis*; D034741:RNA, Small Interfering / Q000378:metabolism; D012627:Sebaceous Glands / Q000166:cytology*; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology; D000099221:Protein Kinase C zeta
chemical_list: D008055:Lipids; D020033:Protein Isoforms; D011493:Protein Kinase C; D051571:Protein Kinase C-alpha; D051745:Protein Kinase C-delta; D051744:Protein Kinase C-epsilon; D034741:RNA, Small Interfering; D013755:Tetradecanoylphorbol Acetate; D000099221:Protein Kinase C zeta; C089212:protein kinase D