title: Impairment of hypoxia-induced HIF-1α signaling in keratinocytes and fibroblasts by sulfur mustard is counteracted by a selective PHD-2 inhibitor.
abstract: Skin exposure to sulfur mustard (SM) provokes long-term complications in wound healing. Similar to chronic wounds, SM-induced skin lesions are associated with low levels of oxygen in the wound tissue. Normally, skin cells respond to hypoxia by stabilization of the transcription factor hypoxia-inducible factor 1 alpha (HIF-1α). HIF-1α modulates expression of genes including VEGFA, BNIP3, and MMP2 that control processes such as angiogenesis, growth, and extracellular proteolysis essential for proper wound healing. The results of our studies revealed that exposure of primary normal human epidermal keratinocytes (NHEK) and primary normal human dermal fibroblasts (NHDF) to SM significantly impaired hypoxia-induced HIF-1α stabilization and target gene expression in these cells. Addition of a selective inhibitor of the oxygen-sensitive prolyl hydroxylase domain-containing protein 2 (PHD-2), IOX2, fully recovered HIF-1α stability, nuclear translocation, and target gene expression in NHEK and NHDF. Moreover, functional studies using a scratch wound assay demonstrated that the application of IOX2 efficiently counteracted SM-mediated deficiencies in monolayer regeneration under hypoxic conditions in NHEK and NHDF. Our findings describe a pathomechanism by which SM negatively affects hypoxia-stimulated HIF-1α signaling in keratinocytes and fibroblasts and thus possibly contributes to delayed wound healing in SM-injured patients that could be treated with PHD-2 inhibitors.
authors.affiliation: Institute for Cardiovascular Prevention, Ludwig-Maximilians-University of Munich, Pettenkoferstraße 9b, 80336, Munich, Germany.
authors.forename: Janina
authors.initials: J
authors.lastname: Deppe
authors.affiliation: Institute for Cardiovascular Prevention, Ludwig-Maximilians-University of Munich, Pettenkoferstraße 9b, 80336, Munich, Germany.
authors.forename: Tanja
authors.initials: T
authors.lastname: Popp
authors.affiliation: Institute for Cardiovascular Prevention, Ludwig-Maximilians-University of Munich, Pettenkoferstraße 9b, 80336, Munich, Germany.
authors.forename: Virginia
authors.initials: V
authors.lastname: Egea
authors.affiliation: Bundeswehr Institute of Pharmacology and Toxicology, Munich, Germany.|Walther-Straub-Institute of Pharmacology and Toxicology, Ludwig-Maximilians-University, Munich, Germany.
authors.forename: Dirk
authors.initials: D
authors.lastname: Steinritz
authors.affiliation: Bundeswehr Institute of Pharmacology and Toxicology, Munich, Germany.|Molecular and Cellular Sport Medicine, German Sport University, Cologne, Germany.
authors.forename: Annette
authors.initials: A
authors.lastname: Schmidt
authors.affiliation: Bundeswehr Institute of Pharmacology and Toxicology, Munich, Germany.
authors.forename: Horst
authors.initials: H
authors.lastname: Thiermann
authors.affiliation: Institute for Cardiovascular Prevention, Ludwig-Maximilians-University of Munich, Pettenkoferstraße 9b, 80336, Munich, Germany.
authors.forename: Christian
authors.initials: C
authors.lastname: Weber
authors.affiliation: Institute for Cardiovascular Prevention, Ludwig-Maximilians-University of Munich, Pettenkoferstraße 9b, 80336, Munich, Germany. christian.ries@med.uni-muenchen.de.
authors.forename: Christian
authors.initials: C
authors.lastname: Ries
mesh_terms: D021581:Active Transport, Cell Nucleus; D000931:Antidotes / Q000494:pharmacology*; D015687:Cell Hypoxia; D049109:Cell Proliferation / Q000187:drug effects; D002478:Cells, Cultured; D002619:Chemical Warfare Agents / Q000633:toxicity*; D004791:Enzyme Inhibitors / Q000494:pharmacology*; D005347:Fibroblasts / Q000187:drug effects* / Q000201:enzymology / Q000473:pathology; D006801:Humans; D051795:Hypoxia-Inducible Factor 1, alpha Subunit / Q000378:metabolism*; D064799:Hypoxia-Inducible Factor-Proline Dioxygenases / Q000037:antagonists & inhibitors* / Q000378:metabolism; D015603:Keratinocytes / Q000187:drug effects* / Q000201:enzymology / Q000473:pathology; D009151:Mustard Gas / Q000633:toxicity*; D055550:Protein Stability; D015398:Signal Transduction / Q000187:drug effects*; D012867:Skin / Q000187:drug effects* / Q000201:enzymology / Q000473:pathology; D013997:Time Factors; D014945:Wound Healing / Q000187:drug effects
chemical_list: D000931:Antidotes; D002619:Chemical Warfare Agents; D004791:Enzyme Inhibitors; C497442:HIF1A protein, human; D051795:Hypoxia-Inducible Factor 1, alpha Subunit; C490190:EGLN1 protein, human; D064799:Hypoxia-Inducible Factor-Proline Dioxygenases; D009151:Mustard Gas
keywords: BNIP3; IOX2; MMP-2; Scratch assay; VEGF-A; Wound healing