title: TMEM45A Is Dispensable for Epidermal Morphogenesis, Keratinization and Barrier Formation.
abstract: TMEM45A gene encodes an initially uncharacterized predicted transmembrane protein. We previously showed that this gene is highly expressed in keratinocytes where its expression correlates with keratinization, suggesting a role in normal epidermal physiology. To test this hypothesis, we generated TMEM45A knockout mice and found that these mice develop without any evident phenotype. The morphology of the epidermis assessed by histology and by labelling differentiation markers in immunofluorescence was not altered. Toluidine blue permeability assay showed that the epidermal barrier develops normally during embryonic development. We also showed that depletion of TMEM45A in human keratinocytes does not alter their potential to form in vitro 3D-reconstructed epidermis. Indeed, epidermis with normal morphogenesis were generated from TMEM45A-silenced keratinocytes. Their expression of differentiation markers quantified by RT-qPCR and evidenced by immunofluorescence labelling as well as their barrier function estimated by Lucifer yellow permeability were similar to the control epidermis. In summary, TMEM45A gene expression is dispensable for epidermal morphogenesis, keratinization and barrier formation. If this protein plays a role in the epidermis, its experimental depletion can possibly be compensated by other proteins in the two experimental models analyzed in this study.
authors.affiliation: URPhyM-NARILIS, University of Namur, Namur, Belgium.
authors.forename: Aurélie
authors.initials: A
authors.lastname: Hayez
authors.affiliation: URBC-NARILIS, University of Namur, Namur, Belgium.
authors.forename: Edith
authors.initials: E
authors.lastname: Roegiers
authors.affiliation: URPhyM-NARILIS, University of Namur, Namur, Belgium.
authors.forename: Jérémy
authors.initials: J
authors.lastname: Malaisse
authors.affiliation: URPhyM-NARILIS, University of Namur, Namur, Belgium.
authors.forename: Benoit
authors.initials: B
authors.lastname: Balau
authors.affiliation: URPhyM-NARILIS, University of Namur, Namur, Belgium.
authors.forename: Christiane
authors.initials: C
authors.lastname: Sterpin
authors.affiliation: Université Catholique de Louvain, de Duve Institute, Brussels, Belgium.
authors.forename: Younes
authors.initials: Y
authors.lastname: Achouri
authors.affiliation: URPhyM-NARILIS, University of Namur, Namur, Belgium.
authors.forename: Catherine Lambert
authors.initials: CL
authors.lastname: De Rouvroit
authors.affiliation: URPhyM-NARILIS, University of Namur, Namur, Belgium.
authors.forename: Yves
authors.initials: Y
authors.lastname: Poumay
authors.affiliation: URBC-NARILIS, University of Namur, Namur, Belgium.
authors.forename: Carine
authors.initials: C
authors.lastname: Michiels
authors.affiliation: URPhyM-NARILIS, University of Namur, Namur, Belgium.
authors.forename: Olivier
authors.initials: O
authors.lastname: De Backer
mesh_terms: D000818:Animals; D015153:Blotting, Western; D002454:Cell Differentiation; D002463:Cell Membrane Permeability; D049109:Cell Proliferation; D002478:Cells, Cultured; D000078404:Epidermal Cells; D004817:Epidermis / Q000378:metabolism; D005260:Female; D006801:Humans; D015603:Keratinocytes / Q000166:cytology* / Q000378:metabolism; D008297:Male; D008565:Membrane Proteins / Q000502:physiology*; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D009024:Morphogenesis / Q000502:physiology*; D038081:Organogenesis / Q000502:physiology; D012333:RNA, Messenger / Q000235:genetics; D060888:Real-Time Polymerase Chain Reaction; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012879:Skin Physiological Phenomena
chemical_list: D008565:Membrane Proteins; D012333:RNA, Messenger; C581204:TMEM45A protein, human