title: Skin Barrier Defects Caused by Keratinocyte-Specific Deletion of ADAM17 or EGFR Are Based on Highly Similar Proteome and Degradome Alterations.
abstract: Keratinocyte-specific deletion of ADAM17 in mice impairs terminal differentiation of keratinocytes leading to severe epidermal barrier defects. Mice deficient for ADAM17 in keratinocytes phenocopy mice with a keratinocyte-specific deletion of epidermal growth factor receptor (EGFR), which highlights the role of ADAM17 as a "ligand sheddase" of EGFR ligands. In this study, we aim for the first proteomic/degradomic approach to characterize the disruption of the ADAM17-EGFR signaling axis and its consequences for epidermal barrier formation. Proteomic profiling of the epidermal proteome of mice deficient for either ADAM17 or EGFR in keratinocytes at postnatal days 3 and 10 revealed highly similar protein alterations for ADAM17 and EGFR deficiency. These include massive proteome alterations of structural and regulatory components important for barrier formation such as transglutaminases, involucrin, filaggrin, and filaggrin-2. Cleavage site analysis using terminal amine isotopic labeling of substrates revealed increased proteolytic processing of S100 fused-type proteins including filaggrin-2. Alterations in proteolytic processing are supported by altered abundance of numerous proteases upon keratinocyte-specific Adam17 or Egfr deletion, among them kallikreins, cathepsins, and their inhibitors. This study highlights the essential role of proteolytic processing for maintenance of a functional epidermal barrier. Furthermore, it suggests that most defects in formation of the postnatal epidermal barrier upon keratinocyte-specific ADAM17 deletion are mediated via EGFR.
authors.affiliation: Institute of Molecular Medicine and Cell Research, University of Freiburg , 79104 Freiburg, Germany.
authors.forename: Stefan
authors.initials: S
authors.lastname: Tholen
authors.affiliation: Department of Dermatology, University Medical Center Freiburg , 79104 Freiburg, Germany.
authors.forename: Cristina
authors.initials: C
authors.lastname: Wolf
authors.affiliation: Institute of Molecular Medicine and Cell Research, University of Freiburg , 79104 Freiburg, Germany.
authors.forename: Bettina
authors.initials: B
authors.lastname: Mayer
authors.affiliation: Institute of Molecular Medicine and Cell Research, University of Freiburg , 79104 Freiburg, Germany.
authors.forename: Julia D
authors.initials: JD
authors.lastname: Knopf
authors.affiliation: Department of Dermatology, University Medical Center Freiburg , 79104 Freiburg, Germany.
authors.forename: Stefanie
authors.initials: S
authors.lastname: Löffek
authors.affiliation: Department of Dermatology, University Medical Center Freiburg , 79104 Freiburg, Germany.
authors.forename: Yawen
authors.initials: Y
authors.lastname: Qian
authors.affiliation: Department of Pathology and Laboratory Medicine and Department of Chemistry, Centre for Blood Research, University of British Columbia , Vancouver, British Columbia V6T 1Z3, Canada.
authors.forename: Jayachandran N
authors.initials: JN
authors.lastname: Kizhakkedathu
authors.affiliation: Institute of Molecular Medicine and Cell Research, University of Freiburg , 79104 Freiburg, Germany.
authors.forename: Martin L
authors.initials: ML
authors.lastname: Biniossek
authors.affiliation: Department of Dermatology, University Medical Center Freiburg , 79104 Freiburg, Germany.
authors.forename: Claus-Werner
authors.initials: CW
authors.lastname: Franzke
authors.affiliation: Institute of Molecular Medicine and Cell Research, University of Freiburg , 79104 Freiburg, Germany.|BIOSS Centre for Biological Signaling Studies, University of Freiburg , D-79104 Freiburg, Germany.|German Cancer Consortium (DKTK) and German Cancer Research Center (DKFZ), 69121 Heidelberg, Germany.
authors.forename: Oliver
authors.initials: O
authors.lastname: Schilling
mesh_terms: D000072198:ADAM17 Protein / Q000172:deficiency* / Q000235:genetics; D000818:Animals; D004817:Epidermis / Q000473:pathology; D066246:ErbB Receptors / Q000172:deficiency* / Q000235:genetics; D017353:Gene Deletion; D015603:Keratinocytes; D051379:Mice; D059748:Proteolysis; D020543:Proteome / Q000032:analysis / Q000378:metabolism*
chemical_list: D020543:Proteome; C541485:EGFR protein, mouse; D066246:ErbB Receptors; D000072198:ADAM17 Protein
keywords: ADAM17; EGFR; TAILS; degradomics; ectodomain shedding; epidermal barrier formation; epidermis; filaggrin-2; proteases; proteomics