title: Knockdown of filaggrin in a three-dimensional reconstructed human epidermis impairs keratinocyte differentiation.
abstract: Atopic dermatitis is a chronic inflammatory skin disorder characterized by defects in the epidermal barrier and keratinocyte differentiation. The expression of filaggrin, a protein thought to have a major role in the function of the epidermis, is downregulated. However, the impact of this deficiency on keratinocytes is not really known. This was investigated using lentivirus-mediated small-hairpin RNA interference in a three-dimensional reconstructed human epidermis (RHE) model, in the absence of other cell types than keratinocytes. Similar to what is known for atopic skin, the experimental filaggrin downregulation resulted in hypogranulosis, a disturbed corneocyte intracellular matrix, reduced amounts of natural moisturizing factor components, increased permeability and UV-B sensitivity of the RHE, and impaired keratinocyte differentiation at the messenger RNA and protein levels. In particular, the amounts of two filaggrin-related proteins and one protease involved in the degradation of filaggrin, bleomycin hydrolase, were lower. In addition, caspase-14 activation was reduced. These results demonstrate the importance of filaggrin for the stratum corneum properties/functions. They indicate that filaggrin downregulation in the epidermis of atopic patients, either acquired or innate, may be directly responsible for some of the disease-related alterations in the epidermal differentiation program and epidermal barrier function.
authors.affiliation: UMR5165 CNRS, Toulouse, France; U1056 INSERM, Toulouse, France; UDEAR, University of Toulouse, Toulouse, France.
authors.forename: Valérie
authors.initials: V
authors.lastname: Pendaries
authors.affiliation: Cell and Tissue Laboratory, URPHYM-NARILIS, University of Namur, Namur, Belgium.
authors.forename: Jeremy
authors.initials: J
authors.lastname: Malaisse
authors.affiliation: UMR5165 CNRS, Toulouse, France; U1056 INSERM, Toulouse, France; UDEAR, University of Toulouse, Toulouse, France.
authors.forename: Laurence
authors.initials: L
authors.lastname: Pellerin
authors.affiliation: UMR5165 CNRS, Toulouse, France; U1056 INSERM, Toulouse, France; UDEAR, University of Toulouse, Toulouse, France.
authors.forename: Marina
authors.initials: M
authors.lastname: Le Lamer
authors.affiliation: UMR5165 CNRS, Toulouse, France; U1056 INSERM, Toulouse, France; UDEAR, University of Toulouse, Toulouse, France.
authors.forename: Rachida
authors.initials: R
authors.lastname: Nachat
authors.affiliation: Academic Medical Center, Coronel Institute of Occupational Health, Amsterdam, The Netherlands.
authors.forename: Sanja
authors.initials: S
authors.lastname: Kezic
authors.affiliation: Pierre Fabre Dermo-Cosmétique, Toulouse, France.
authors.forename: Anne-Marie
authors.initials: AM
authors.lastname: Schmitt
authors.affiliation: UMR5165 CNRS, Toulouse, France; U1056 INSERM, Toulouse, France; UDEAR, University of Toulouse, Toulouse, France; University Hospital, Toulouse, France.
authors.forename: Carle
authors.initials: C
authors.lastname: Paul
authors.affiliation: Cell and Tissue Laboratory, URPHYM-NARILIS, University of Namur, Namur, Belgium.
authors.forename: Yves
authors.initials: Y
authors.lastname: Poumay
authors.affiliation: UMR5165 CNRS, Toulouse, France; U1056 INSERM, Toulouse, France; UDEAR, University of Toulouse, Toulouse, France.
authors.forename: Guy
authors.initials: G
authors.lastname: Serre
authors.affiliation: UMR5165 CNRS, Toulouse, France; U1056 INSERM, Toulouse, France; UDEAR, University of Toulouse, Toulouse, France. Electronic address: michel.simon@udear.cnrs.fr.
authors.forename: Michel
authors.initials: M
authors.lastname: Simon
mesh_terms: D000293:Adolescent; D000328:Adult; D016022:Case-Control Studies; D053456:Caspase 14 / Q000378:metabolism; D002454:Cell Differentiation / Q000187:drug effects* / Q000502:physiology*; D002463:Cell Membrane Permeability / Q000187:drug effects / Q000502:physiology; D002478:Cells, Cultured; D003876:Dermatitis, Atopic / Q000378:metabolism / Q000473:pathology / Q000503:physiopathology; D015536:Down-Regulation / Q000187:drug effects*; D004817:Epidermis / Q000187:drug effects / Q000473:pathology*; D005260:Female; D000091344:Filaggrin Proteins; D055785:Gene Knockdown Techniques; D006801:Humans; D007381:Intermediate Filament Proteins / Q000172:deficiency* / Q000235:genetics / Q000502:physiology; D015603:Keratinocytes / Q000187:drug effects / Q000473:pathology*; D008297:Male; D008875:Middle Aged; D034741:RNA, Small Interfering / Q000494:pharmacology*; D011836:Radiation Tolerance / Q000187:drug effects / Q000528:radiation effects; D012867:Skin / Q000378:metabolism / Q000473:pathology; D014466:Ultraviolet Rays / Q000009:adverse effects; D055815:Young Adult
chemical_list: C000717249:FLG protein, human; D000091344:Filaggrin Proteins; D007381:Intermediate Filament Proteins; D034741:RNA, Small Interfering; D053456:Caspase 14