title: Transcription factor binding site analysis identifies FOXO transcription factors as regulators of the cutaneous wound healing process.
abstract: The search for significantly overrepresented and co-occurring transcription factor binding sites in the promoter regions of the most differentially expressed genes in microarray data sets could be a powerful approach for finding key regulators of complex biological processes. To test this concept, two previously published independent data sets on wounded human epidermis were re-analyzed. The presence of co-occurring transcription factor binding sites for FOXO1, FOXO3 and FOXO4 in the majority of the promoter regions of the most significantly differentially expressed genes between non-wounded and wounded epidermis implied an important role for FOXO transcription factors during wound healing. Expression levels of FOXO transcription factors during wound healing in vivo in both human and mouse skin were analyzed and a decrease for all FOXOs in human wounded skin was observed, with FOXO3 having the highest expression level in non wounded skin. Impaired re-epithelialization was found in cultures of primary human keratinocytes expressing a constitutively active variant of FOXO3. Conversely knockdown of FOXO3 in keratinocytes had the opposite effect and in an in vivo mouse model with FOXO3 knockout mice we detected significantly accelerated wound healing. This article illustrates that the proposed approach is a viable method for identifying important regulators of complex biological processes using in vivo samples. FOXO3 has not previously been implicated as an important regulator of wound healing and its exact function in this process calls for further investigation.
authors.affiliation: Department of Pediatrics, University of California San Diego, La Jolla, California, United States of America.
authors.forename: Karl Markus
authors.initials: KM
authors.lastname: Roupé
authors.affiliation: Division of Oncology, Department of Clinical Sciences, Lund University and Lund University Hospital, Lund, Sweden.
authors.forename: Srinivas
authors.initials: S
authors.lastname: Veerla
authors.affiliation: Department of Pediatrics, University of California San Diego, La Jolla, California, United States of America.
authors.forename: Joshua
authors.initials: J
authors.lastname: Olson
authors.affiliation: Molecular Biology Section, Division of Biological Sciences, University of California San Diego, San Diego, California, United States of America ; Department of Cellular and Molecular Medicine, University of California San Diego, San Diego, California, United States of America.
authors.forename: Erica L
authors.initials: EL
authors.lastname: Stone
authors.affiliation: Division of Infection Medicine, Department of Clinical Sciences, Lund University, Lund, Sweden.
authors.forename: Ole E
authors.initials: OE
authors.lastname: Sørensen
authors.affiliation: Molecular Biology Section, Division of Biological Sciences, University of California San Diego, San Diego, California, United States of America ; Department of Cellular and Molecular Medicine, University of California San Diego, San Diego, California, United States of America.
authors.forename: Stephen M
authors.initials: SM
authors.lastname: Hedrick
authors.affiliation: Department of Pediatrics, University of California San Diego, La Jolla, California, United States of America ; Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California San Diego, La Jolla, California, United States of America.
authors.forename: Victor
authors.initials: V
authors.lastname: Nizet
mesh_terms: D000818:Animals; D001665:Binding Sites / Q000235:genetics*; D017931:DNA Primers / Q000235:genetics; D004817:Epidermis / Q000502:physiology*; D000071161:Forkhead Box Protein O1; D000071316:Forkhead Box Protein O3; D051858:Forkhead Transcription Factors / Q000235:genetics / Q000378:metabolism*; D006801:Humans; D007150:Immunohistochemistry; D015603:Keratinocytes / Q000378:metabolism; D051379:Mice; D018345:Mice, Knockout; D046228:Microarray Analysis; D008856:Microscopy, Fluorescence; D060888:Real-Time Polymerase Chain Reaction; D013045:Species Specificity; D013297:Streptococcus pyogenes; D014945:Wound Healing / Q000502:physiology*
chemical_list: D017931:DNA Primers; C085126:FOXO1 protein, human; D000071161:Forkhead Box Protein O1; D000071316:Forkhead Box Protein O3; D051858:Forkhead Transcription Factors; C474033:FoxO3 protein, mouse