title: Spontaneous skin erosions and reduced skin and corneal wound healing characterize CLIC4(NULL) mice.
abstract: Cutaneous wound healing is a complex process involving blood clotting, inflammation, migration of keratinocytes, angiogenesis, and, ultimately, tissue remodeling and wound closure. Many of these processes involve transforming growth factor-β (TGF-β) signaling, and mice lacking components of the TGF-β signaling pathway are defective in wound healing. We show herein that CLIC4, an integral component of the TGF-β pathway, is highly up-regulated in skin wounds. We genetically deleted murine CLIC4 and generated a colony on a C57Bl/6 background. CLIC4(NULL) mice were viable and fertile but had smaller litters than did wild-type mice. After 6 months of age, up to 40% of null mice developed spontaneous skin erosions. Reepithelialization of induced full-thickness skin wounds and superficial corneal wounds was delayed in CLIC4(NULL) mice, resolution of inflammation was delayed, and expression of β4 integrin and p21 was reduced in lysates of constitutive and wounded CLIC4(NULL) skin. The induced level of phosphorylated Smad2 in response to TGF-β was reduced in cultured CLIC4(NULL) keratinocytes relative to in wild-type cells, and CLIC4(NULL) keratinocytes migrated slower than did wild-type keratinocytes and did not increase migration in response to TGF-β. CLIC4(NULL) keratinocytes were also less adherent on plates coated with matrix secreted by wild-type keratinocytes. These results indicate that CLIC4 participates in skin healing and corneal wound reepithelialization through enhancement of epithelial migration by a mechanism that may involve a compromised TGF-β pathway.
authors.affiliation: Laboratory of Cancer Biology and Genetics, National Cancer Institute, Bethesda, MD 20892, USA.
authors.forename: V C
authors.initials: VC
authors.lastname: Padmakumar
authors.forename: Kelsey
authors.initials: K
authors.lastname: Speer
authors.forename: Sonali
authors.initials: S
authors.lastname: Pal-Ghosh
authors.forename: Katelyn E
authors.initials: KE
authors.lastname: Masiuk
authors.forename: Andrew
authors.initials: A
authors.lastname: Ryscavage
authors.forename: Samuel L
authors.initials: SL
authors.lastname: Dengler
authors.forename: Shelly
authors.initials: S
authors.lastname: Hwang
authors.forename: John C
authors.initials: JC
authors.lastname: Edwards
authors.forename: Vincenzo
authors.initials: V
authors.lastname: Coppola
authors.forename: Lino
authors.initials: L
authors.lastname: Tessarollo
authors.forename: Mary Ann
authors.initials: MA
authors.lastname: Stepp
authors.forename: Stuart H
authors.initials: SH
authors.lastname: Yuspa
mesh_terms: D000818:Animals; D002448:Cell Adhesion / Q000502:physiology; D002465:Cell Movement / Q000502:physiology; D002478:Cells, Cultured; D018118:Chloride Channels / Q000172:deficiency / Q000502:physiology*; D003315:Cornea / Q000473:pathology / Q000502:physiology; D065306:Corneal Injuries; D004305:Dose-Response Relationship, Drug; D015603:Keratinocytes / Q000187:drug effects / Q000378:metabolism / Q000502:physiology; D051379:Mice; D018345:Mice, Knockout; D018613:Microscopy, Confocal; D024101:Mitochondrial Proteins / Q000172:deficiency / Q000502:physiology*; D011506:Proteins / Q000378:metabolism; D015398:Signal Transduction / Q000502:physiology; D012867:Skin / Q000293:injuries* / Q000378:metabolism / Q000473:pathology; D012883:Skin Ulcer / Q000473:pathology / Q000503:physiopathology*; D013997:Time Factors; D016212:Transforming Growth Factor beta / Q000008:administration & dosage / Q000494:pharmacology; D014945:Wound Healing / Q000502:physiology*
chemical_list: C479423:CLIC protein, mouse; D018118:Chloride Channels; D024101:Mitochondrial Proteins; D011506:Proteins; D016212:Transforming Growth Factor beta