title: E-FABP induces differentiation in normal human keratinocytes and modulates the differentiation process in psoriatic keratinocytes in vitro.
abstract: Epidermal fatty acid-binding protein (E-FABP) is a lipid carrier, originally discovered in human epidermis. We show that E-FABP is almost exclusively expressed in postmitotic (PM) keratinocytes, corresponding to its localization in the highest suprabasal layers, while it is barely expressed in keratinocyte stem cells (KSC) and transit amplifying (TA) keratinocytes. Transfection of normal human keratinocytes with recombinant (r) E-FABP induces overexpression of K10 and involucrin. On the other hand, E-FABP inhibition by siRNA downregulates K10 and involucrin expression in normal keratinocytes through NF-κB and JNK signalling pathways. E-FABP is highly expressed in psoriatic epidermis, and it is mainly localized in stratum spinosum. Psoriatic PM keratinocytes overexpress E-FABP as compared to the same population in normal epidermis. E-FABP inhibition in psoriatic keratinocytes markedly reduces differentiation, while it upregulates psoriatic markers such as survivin and K16. However, under high-calcium conditions, E-FABP silencing downregulates K10 and involucrin, while survivin and K16 expression is completely abolished. These data strongly indicate that E-FABP plays an important role in keratinocyte differentiation. Moreover, E-FABP modulates differentiation in psoriatic keratinocytes.
authors.affiliation: Institute of Dermatology, School of Medicine, University of Modena and Reggio Emilia, Modena, Italy.
authors.forename: Katiuscia
authors.initials: K
authors.lastname: Dallaglio
authors.forename: Alessandra
authors.initials: A
authors.lastname: Marconi
authors.forename: Francesca
authors.initials: F
authors.lastname: Truzzi
authors.forename: Roberta
authors.initials: R
authors.lastname: Lotti
authors.forename: Elisabetta
authors.initials: E
authors.lastname: Palazzo
authors.forename: Tiziana
authors.initials: T
authors.lastname: Petrachi
authors.forename: Annalisa
authors.initials: A
authors.lastname: Saltari
authors.forename: Maurizio
authors.initials: M
authors.lastname: Coppini
authors.forename: Carlo
authors.initials: C
authors.lastname: Pincelli
mesh_terms: D002454:Cell Differentiation / Q000502:physiology; D002478:Cells, Cultured; D050556:Fatty Acid-Binding Proteins / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism*; D006801:Humans; D053550:Keratin-10 / Q000378:metabolism; D015603:Keratinocytes / Q000166:cytology* / Q000473:pathology / Q000502:physiology*; D011498:Protein Precursors / Q000378:metabolism; D011565:Psoriasis / Q000378:metabolism* / Q000473:pathology*; D034741:RNA, Small Interfering / Q000235:genetics; D011994:Recombinant Proteins / Q000235:genetics / Q000378:metabolism
chemical_list: C493412:FABP5 protein, human; D050556:Fatty Acid-Binding Proteins; C507493:KRT10 protein, human; D011498:Protein Precursors; D034741:RNA, Small Interfering; D011994:Recombinant Proteins; D053550:Keratin-10; C032253:involucrin