title: Keratinocyte-/fibroblast-targeted rescue of Col7a1-disrupted mice and generation of an exact dystrophic epidermolysis bullosa model using a human COL7A1 mutation.
abstract: Recessive dystrophic epidermolysis bullosa (RDEB) is a severe hereditary bullous disease caused by mutations in COL7A1, which encodes type VII collagen (COL7). Col7a1 knockout mice (COL7(m-/-)) exhibit a severe RDEB phenotype and die within a few days after birth. Toward developing novel approaches for treating patients with RDEB, we attempted to rescue COL7(m-/-) mice by introducing human COL7A1 cDNA. We first generated transgenic mice that express human COL7A1 cDNA specifically in either epidermal keratinocytes or dermal fibroblasts. We then performed transgenic rescue experiments by crossing these transgenic mice with COL7(m+/-) heterozygous mice. Surprisingly, human COL7 expressed by keratinocytes or by fibroblasts was able to rescue all of the abnormal phenotypic manifestations of the COL7(m-/-) mice, indicating that fibroblasts as well as keratinocytes are potential targets for RDEB gene therapy. Furthermore, we generated transgenic mice with a premature termination codon expressing truncated COL7 protein and performed the same rescue experiments. Notably, the COL7(m-/-) mice rescued with the human COL7A1 allele were able to survive despite demonstrating clinical manifestations very similar to those of human RDEB, indicating that we were able to generate surviving animal models of RDEB with a mutated human COL7A1 gene. This model has great potential for future research into the pathomechanisms of dystrophic epidermolysis bullosa and the development of gene therapies for patients with dystrophic epidermolysis bullosa.
authors.affiliation: Department of Dermatology, Hokkaido University Graduate School of Medicine, Kita-ku, Sapporo, Japan.
authors.forename: Kei
authors.initials: K
authors.lastname: Ito
authors.forename: Daisuke
authors.initials: D
authors.lastname: Sawamura
authors.forename: Maki
authors.initials: M
authors.lastname: Goto
authors.forename: Hideki
authors.initials: H
authors.lastname: Nakamura
authors.forename: Wataru
authors.initials: W
authors.lastname: Nishie
authors.forename: Kaori
authors.initials: K
authors.lastname: Sakai
authors.forename: Ken
authors.initials: K
authors.lastname: Natsuga
authors.forename: Satoru
authors.initials: S
authors.lastname: Shinkuma
authors.forename: Akihiko
authors.initials: A
authors.lastname: Shibaki
authors.forename: Jouni
authors.initials: J
authors.lastname: Uitto
authors.forename: Christopher P
authors.initials: CP
authors.lastname: Denton
authors.forename: Osamu
authors.initials: O
authors.lastname: Nakajima
authors.forename: Masashi
authors.initials: M
authors.lastname: Akiyama
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Shimizu
mesh_terms: D000818:Animals; D015153:Blotting, Western; D024143:Collagen Type VII / Q000235:genetics*; D018076:DNA, Complementary / Q000235:genetics; D004195:Disease Models, Animal; D016108:Epidermolysis Bullosa Dystrophica / Q000235:genetics*; D005347:Fibroblasts / Q000502:physiology*; D005455:Fluorescent Antibody Technique; D005818:Genetic Engineering / Q000379:methods; D006801:Humans; D007150:Immunohistochemistry; D015603:Keratinocytes / Q000502:physiology*; D051379:Mice; D008822:Mice, Transgenic; D016253:Microscopy, Immunoelectron; D009154:Mutation; D020133:Reverse Transcriptase Polymerase Chain Reaction
chemical_list: D024143:Collagen Type VII; D018076:DNA, Complementary