title: Foxn1 Transcription Factor Regulates Wound Healing of Skin through Promoting Epithelial-Mesenchymal Transition.
abstract: Transcription factors are key molecules that finely tune gene expression in response to injury. We focused on the role of a transcription factor, Foxn1, whose expression is limited to the skin and thymus epithelium. Our previous studies showed that Foxn1 inactivity in nude mice creates a pro-regenerative environment during skin wound healing. To explore the mechanistic role of Foxn1 in the skin wound healing process, we analyzed post-injured skin tissues from Foxn1::Egfp transgenic and C57BL/6 mice with Western Blotting, qRT-PCR, immunofluorescence and flow cytometric assays. Foxn1 expression in non-injured skin localized to the epidermis and hair follicles. Post-injured skin tissues showed an intense Foxn1-eGFP signal at the wound margin and in leading epithelial tongue, where it co-localized with keratin 16, a marker of activated keratinocytes. This data support the concept that suprabasal keratinocytes, expressing Foxn1, are key cells in the process of re-epithelialization. The occurrence of an epithelial-mesenchymal transition (EMT) was confirmed by high levels of Snail1 and Mmp-9 expression as well as through co-localization of vimentin/E-cadherin-positive cells in dermis tissue at four days post-wounding. Involvement of Foxn1 in the EMT process was verified by co-localization of Foxn1-eGFP cells with Snail1 in histological sections. Flow cytometric analysis showed the increase of double positive E-cadherin/N-cadherin cells within Foxn1-eGFP population of post-wounded skin cells isolates, which corroborated histological and gene expression analyses. Together, our findings indicate that Foxn1 acts as regulator of the skin wound healing process through engagement in re-epithelization and possible involvement in scar formation due to Foxn1 activity during the EMT process.
authors.affiliation: Institute of Animal Reproduction and Food Research of Polish Academy of Sciences, Olsztyn, Poland.
authors.forename: Barbara
authors.initials: B
authors.lastname: Gawronska-Kozak
authors.affiliation: Institute of Animal Reproduction and Food Research of Polish Academy of Sciences, Olsztyn, Poland.
authors.forename: Anna
authors.initials: A
authors.lastname: Grabowska
authors.affiliation: Institute of Animal Reproduction and Food Research of Polish Academy of Sciences, Olsztyn, Poland.
authors.forename: Anna
authors.initials: A
authors.lastname: Kur-Piotrowska
authors.affiliation: Institute of Animal Reproduction and Food Research of Polish Academy of Sciences, Olsztyn, Poland.
authors.forename: Marta
authors.initials: M
authors.lastname: Kopcewicz
mesh_terms: D000818:Animals; D015820:Cadherins / Q000235:genetics / Q000378:metabolism; D058750:Epithelial-Mesenchymal Transition / Q000235:genetics*; D005260:Female; D051858:Forkhead Transcription Factors / Q000235:genetics* / Q000378:metabolism; D005786:Gene Expression Regulation; D017930:Genes, Reporter; D049452:Green Fluorescent Proteins / Q000235:genetics / Q000378:metabolism; D053536:Keratin-16 / Q000235:genetics / Q000378:metabolism; D015603:Keratinocytes / Q000378:metabolism / Q000473:pathology; D008297:Male; D020780:Matrix Metalloproteinase 9 / Q000235:genetics / Q000378:metabolism; D051379:Mice; D008810:Mice, Inbred C57BL; D008822:Mice, Transgenic; D015398:Signal Transduction; D012867:Skin / Q000293:injuries / Q000378:metabolism*; D000071250:Snail Family Transcription Factors; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism; D014746:Vimentin / Q000235:genetics / Q000378:metabolism; D014945:Wound Healing / Q000235:genetics*; D014950:Wounds, Penetrating / Q000378:metabolism* / Q000473:pathology
chemical_list: D015820:Cadherins; D051858:Forkhead Transcription Factors; D053536:Keratin-16; C000604429:Snai1 protein, mouse; D000071250:Snail Family Transcription Factors; D014157:Transcription Factors; D014746:Vimentin; C090140:Whn protein; C485184:enhanced green fluorescent protein; D049452:Green Fluorescent Proteins; D020780:Matrix Metalloproteinase 9