title: Development of transgenic cloned pig models of skin inflammation by DNA transposon-directed ectopic expression of human β1 and α2 integrin.
abstract: Integrins constitute a superfamily of transmembrane signaling receptors that play pivotal roles in cutaneous homeostasis by modulating cell growth and differentiation as well as inflammatory responses in the skin. Subrabasal expression of integrins α2 and/or β1 entails hyperproliferation and aberrant differentiation of keratinocytes and leads to dermal and epidermal influx of activated T-cells. The anatomical and physiological similarities between porcine and human skin make the pig a suitable model for human skin diseases. In efforts to generate a porcine model of cutaneous inflammation, we employed the Sleeping Beauty DNA transposon system for production of transgenic cloned Göttingen minipigs expressing human β1 or α2 integrin under the control of a promoter specific for subrabasal keratinocytes. Using pools of transgenic donor fibroblasts, cloning by somatic cell nuclear transfer was utilized to produce reconstructed embryos that were subsequently transferred to surrogate sows. The resulting pigs were all transgenic and harbored from one to six transgene integrants. Molecular analyses on skin biopsies and cultured keratinocytes showed ectopic expression of the human integrins and localization within the keratinocyte plasma membrane. Markers of perturbed skin homeostasis, including activation of the MAPK pathway, increased expression of the pro-inflammatory cytokine IL-1α, and enhanced expression of the transcription factor c-Fos, were identified in keratinocytes from β1 and α2 integrin-transgenic minipigs, suggesting the induction of a chronic inflammatory phenotype in the skin. Notably, cellular dysregulation obtained by overexpression of either β1 or α2 integrin occurred through different cellular signaling pathways. Our findings mark the creation of the first cloned pig models with molecular markers of skin inflammation. Despite the absence of an overt psoriatic phenotype, these animals may possess increased susceptibility to severe skin damage-induced inflammation and should be of great potential in studies aiming at the development and refinement of topical therapies for cutaneous inflammation including psoriasis.
authors.affiliation: Department of Biomedicine, Aarhus University, Aarhus, Denmark.
authors.forename: Nicklas Heine
authors.initials: NH
authors.lastname: Staunstrup
authors.forename: Johannes
authors.initials: J
authors.lastname: Madsen
authors.forename: Maria Nascimento
authors.initials: MN
authors.lastname: Primo
authors.forename: Juan
authors.initials: J
authors.lastname: Li
authors.forename: Ying
authors.initials: Y
authors.lastname: Liu
authors.forename: Peter M
authors.initials: PM
authors.lastname: Kragh
authors.forename: Rong
authors.initials: R
authors.lastname: Li
authors.forename: Mette
authors.initials: M
authors.lastname: Schmidt
authors.forename: Stig
authors.initials: S
authors.lastname: Purup
authors.forename: Frederik
authors.initials: F
authors.lastname: Dagnæs-Hansen
authors.forename: Lars
authors.initials: L
authors.lastname: Svensson
authors.forename: Thomas K
authors.initials: TK
authors.lastname: Petersen
authors.forename: Henrik
authors.initials: H
authors.lastname: Callesen
authors.forename: Lars
authors.initials: L
authors.lastname: Bolund
authors.forename: Jacob Giehm
authors.initials: JG
authors.lastname: Mikkelsen
mesh_terms: D000818:Animals; D030801:Animals, Genetically Modified / Q000235:genetics / Q000378:metabolism*; D015415:Biomarkers / Q000378:metabolism; D019976:Cloning, Organism; D004251:DNA Transposable Elements; D003872:Dermatitis / Q000235:genetics / Q000378:metabolism* / Q000473:pathology / Q000628:therapy; D004195:Disease Models, Animal; D005786:Gene Expression Regulation; D006801:Humans; D039421:Integrin alpha2 / Q000096:biosynthesis* / Q000235:genetics; D019012:Integrin beta1 / Q000096:biosynthesis* / Q000235:genetics; D015603:Keratinocytes / Q000378:metabolism / Q000473:pathology; D011565:Psoriasis / Q000235:genetics / Q000378:metabolism* / Q000473:pathology / Q000628:therapy; D013552:Swine; D013556:Swine, Miniature / Q000235:genetics / Q000378:metabolism*
chemical_list: D015415:Biomarkers; D004251:DNA Transposable Elements; D039421:Integrin alpha2; D019012:Integrin beta1