title: A pituitary homeobox 2 (Pitx2):microRNA-200a-3p:β-catenin pathway converts mesenchymal cells to amelogenin-expressing dental epithelial cells.
abstract: Pitx2, Wnt/β-catenin signaling, and microRNAs (miRs) play a critical role in the regulation of dental stem cells during embryonic development. In this report, we have identified a Pitx2:β-catenin regulatory pathway involved in epithelial cell differentiation and conversion of mesenchymal cells to amelogenin expressing epithelial cells via miR-200a. Pitx2 and β-catenin are expressed in the labial incisor cervical loop or epithelial stem cell niche, with decreased expression in the differentiating ameloblast cells of the mouse lower incisor. Bioinformatics analyses reveal that miR-200a-3p expression is activated in the pre-ameloblast cells to enhance epithelial cell differentiation. We demonstrate that Pitx2 activates miR-200a-3p expression and miR-200a-3p reciprocally represses Pitx2 and β-catenin expression. Pitx2 and β-catenin interact to synergistically activate gene expression during odontogenesis and miR-200a-3p attenuates their expression and directs differentiation. To understand how this mechanism controls cell differentiation and cell fate, oral epithelial and odontoblast mesenchymal cells were reprogrammed by a two-step induction method using Pitx2 and miR-200a-3p. Conversion to amelogenin expressing dental epithelial cells involved an up-regulation of the stem cell marker Sox2 and proliferation genes and decreased expression of mesenchymal markers. E-cadherin expression was increased as well as ameloblast specific factors. The combination of Pitx2, a regulator of dental stem cells and miR-200a converts mesenchymal cells to a fully differentiated dental epithelial cell type. This pathway and reprogramming can be used to reprogram mesenchymal or oral epithelial cells to dental epithelial (ameloblast) cells, which can be used in tissue repair and regeneration studies.
authors.affiliation: Department of Anatomy and Cell Biology, Carver College of Medicine, University of Iowa, Iowa City, Iowa 52242.
authors.forename: Thad
authors.initials: T
authors.lastname: Sharp
authors.affiliation: Institute of Biosciences and Technology, Texas A&M Health Science Center, Houston, Texas 77030, and.
authors.forename: Jianbo
authors.initials: J
authors.lastname: Wang
authors.affiliation: Department of Anatomy and Cell Biology, Carver College of Medicine, University of Iowa, Iowa City, Iowa 52242.
authors.forename: Xiao
authors.initials: X
authors.lastname: Li
authors.affiliation: Institute of Biosciences and Technology, Texas A&M Health Science Center, Houston, Texas 77030, and.
authors.forename: Huojun
authors.initials: H
authors.lastname: Cao
authors.affiliation: Institute of Biosciences and Technology, Texas A&M Health Science Center, Houston, Texas 77030, and.
authors.forename: Shan
authors.initials: S
authors.lastname: Gao
authors.affiliation: Department of Anatomy and Cell Biology, Carver College of Medicine, University of Iowa, Iowa City, Iowa 52242.
authors.forename: Myriam
authors.initials: M
authors.lastname: Moreno
authors.affiliation: Department of Anatomy and Cell Biology, Carver College of Medicine, University of Iowa, Iowa City, Iowa 52242,; Craniofacial Anomalies Research Center, Carver College of Medicine, University of Iowa, Iowa City, Iowa 52242. Electronic address: brad-amendt@uiowa.edu.
authors.forename: Brad A
authors.initials: BA
authors.lastname: Amendt
mesh_terms: D053523:Amelogenin / Q000235:genetics / Q000378:metabolism*; D000818:Animals; D002454:Cell Differentiation / Q000502:physiology*; D004847:Epithelial Cells / Q000166:cytology / Q000378:metabolism*; D018398:Homeodomain Proteins / Q000235:genetics / Q000378:metabolism*; D006801:Humans; D007180:Incisor / Q000166:cytology / Q000378:metabolism*; D059630:Mesenchymal Stem Cells / Q000166:cytology / Q000378:metabolism*; D051379:Mice; D008822:Mice, Transgenic; D035683:MicroRNAs / Q000235:genetics / Q000378:metabolism*; D055748:SOXB1 Transcription Factors / Q000235:genetics / Q000378:metabolism; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism*; D051176:beta Catenin / Q000235:genetics / Q000378:metabolism*; D000097577:Homeobox Protein PITX2
chemical_list: D053523:Amelogenin; D018398:Homeodomain Proteins; D035683:MicroRNAs; D055748:SOXB1 Transcription Factors; D014157:Transcription Factors; D051176:beta Catenin; D000097577:Homeobox Protein PITX2; C533896:MIRN200 microRNA, human; C543719:Mirn200 microRNA, mouse; C527782:SOX2 protein, human; C527783:Sox2 protein, mouse
keywords: Beta-catenin (B-catenin); Epithelial-Mesenchymal Transition (EMT); Gene Expression; MicroRNA (miRNA); Paired-like Homeodomain Transcription Factor 2 (PITX2); Reprogramming