title: Overexpression of the Flii gene increases dermal-epidermal blistering in an autoimmune ColVII mouse model of epidermolysis bullosa acquisita.
abstract: Epidermolysis bullosa (EB) is a severe genetic skin fragility syndrome characterized by blister formation. The molecular basis of EB is still largely unknown and wound healing in patients suffering from EB remains a major challenge to their survival. Our previous studies have identified the actin remodelling protein Flightless I (Flii) as an important mediator of wound repair. Here we identify Flii as a novel target involved in skin blistering. Flii expression was significantly elevated in 30 patients with EB, most prominently in patients with recessive dystrophic EB (RDEB) who have defects in production of type VII collagen (ColVII). Using an autoimmune ColVII murine model of EB acquisita (EBA) and an immunocompetent-ColVII-hypomorphic genetic mouse model of RDEB together with murine Flii alleles, we investigated the contribution of Flii to EB. Overexpression of Flii produced severe blistering post-induction of EBA, while decreased Flii reduced blister severity, elevated integrin expression, and improved ColVII production. Flii(+/-) blistered skin showed reduced α-SMA, TGF-β1, and Smad 2/3 expression, suggesting that decreasing Flii may affect fibrosis. In support of this, Flii-deficient fibroblasts from EBA mice were less able to contract collagen gels in vitro; however, addition of TGF-β1 restored collagen contraction, suggesting an interplay between Flii and TGF-β1. Elevated Flii gene and protein expression was further observed in the blisters of ColVII hypomorphic mice, a murine model of RDEB, suggesting that reducing Flii in blistered skin could be a potential new approach for treating patients with EB.
authors: Women's and Children's Health Research Institute, 72 King William Road, North Adelaide, SA, Australia.
authors: Zlatko
authors: Z
authors: Kopecki
authors: Ruth M
authors: RM
authors: Arkell
authors: Xanthe L
authors: XL
authors: Strudwick
authors: Misa
authors: M
authors: Hirose
authors: Ralf J
authors: RJ
authors: Ludwig
authors: Johannes S
authors: JS
authors: Kern
authors: Leena
authors: L
authors: Bruckner-Tuderman
authors: Detlef
authors: D
authors: Zillikens
authors: Dedee F
authors: DF
authors: Murrell
authors: Allison J
authors: AJ
authors: Cowin
mesh_terms: D000818:Animals; D001327:Autoimmune Diseases / Q000235:genetics / Q000378:metabolism* / Q000473:pathology; D002352:Carrier Proteins; D002448:Cell Adhesion / Q000502:physiology; D002454:Cell Differentiation / Q000502:physiology; D049109:Cell Proliferation; D002478:Cells, Cultured; D024143:Collagen Type VII / Q000096:biosynthesis; D003598:Cytoskeletal Proteins / Q000096:biosynthesis* / Q000235:genetics; D004195:Disease Models, Animal; D016107:Epidermolysis Bullosa Acquisita / Q000235:genetics / Q000378:metabolism* / Q000473:pathology; D005347:Fibroblasts / Q000473:pathology / Q000502:physiology; D005786:Gene Expression Regulation; D006801:Humans; D016023:Integrins / Q000378:metabolism; D051379:Mice; D008807:Mice, Inbred BALB C; D008822:Mice, Transgenic; D008840:Microfilament Proteins / Q000096:biosynthesis / Q000235:genetics; D018160:Receptors, Cytoplasmic and Nuclear / Q000096:biosynthesis / Q000235:genetics; D015398:Signal Transduction / Q000502:physiology; D012867:Skin / Q000378:metabolism; D051785:Smad Proteins / Q000502:physiology; D015534:Trans-Activators; D053773:Transforming Growth Factor beta1 / Q000502:physiology; D014945:Wound Healing / Q000502:physiology
chemical_list: D002352:Carrier Proteins; D024143:Collagen Type VII; D003598:Cytoskeletal Proteins; C098179:FLII protein, human; C000609263:FlII protein, mouse; D016023:Integrins; D008840:Microfilament Proteins; D018160:Receptors, Cytoplasmic and Nuclear; D051785:Smad Proteins; D015534:Trans-Activators; D053773:Transforming Growth Factor beta1