title: Expression of paired-like homeodomain transcription factor 2c (PITX2c) in epidermal keratinocytes.
abstract: Paired-like homeodomain transcription factor 2 (PITX2) has been implicated as one of the genes responsible for Rieger syndrome. It has been also shown to play a central role during development. In this study, we investigated the functional role of PITX2 in keratinocyte differentiation. RT-PCR analysis showed that PITX2c isoform was predominantly expressed in a differentiation-dependent manner. Consistent with, immunohistochemical staining showed that PITX2 expression was increased in the upper layer of epidermis. When PITX2c was overexpressed in cultured keratinocytes by a recombinant adenovirus, the differentiation markers such as involucrin and loricrin were significantly increased at both mRNA and protein levels. In addition, PITX2c overexpression led to the decrease of cell growth, concomitantly with the upregulation of cell cycle-related genes p21. To investigate the effect of PITX2c in vivo, we microinjected PITX2c expression vector into zebrafish embryo. Interestingly, overexpression of PITX2c in zebrafish embryo led to the formation of horn-like structure and thickening of epidermis, together with the increase of keratin 8 (K8) expression. These results suggest that PITX2c has a role in proliferation and differentiation of epidermal keratinocytes.
authors.affiliation: Department of Dermatology, School of Medicine, Chungnam National University, Daejeon, 301-747, Republic of Korea.
authors.forename: Ge
authors.initials: G
authors.lastname: Shi
authors.forename: Kyung-Cheol
authors.initials: KC
authors.lastname: Sohn
authors.forename: Tae-Young
authors.initials: TY
authors.lastname: Choi
authors.forename: Dae-Kyoung
authors.initials: DK
authors.lastname: Choi
authors.forename: Sang-Sin
authors.initials: SS
authors.lastname: Lee
authors.forename: Bai-sheng
authors.initials: BS
authors.lastname: Ou
authors.forename: Sooil
authors.initials: S
authors.lastname: Kim
authors.forename: Young Ho
authors.initials: YH
authors.lastname: Lee
authors.forename: Tae-Jin
authors.initials: TJ
authors.lastname: Yoon
authors.forename: Seong-Jin
authors.initials: SJ
authors.lastname: Kim
authors.forename: Young
authors.initials: Y
authors.lastname: Lee
authors.forename: Young-Joon
authors.initials: YJ
authors.lastname: Seo
authors.forename: Jeung-Hoon
authors.initials: JH
authors.lastname: Lee
authors.forename: Chang Deok
authors.initials: CD
authors.lastname: Kim
mesh_terms: D000818:Animals; D002454:Cell Differentiation; D049109:Cell Proliferation; D004625:Embryo, Nonmammalian / Q000166:cytology / Q000378:metabolism; D000078404:Epidermal Cells; D018398:Homeodomain Proteins / Q000378:metabolism*; D006801:Humans; D015603:Keratinocytes / Q000166:cytology / Q000378:metabolism*; D014157:Transcription Factors / Q000378:metabolism*; D015027:Zebrafish / Q000196:embryology; D000097577:Homeobox Protein PITX2
chemical_list: D018398:Homeodomain Proteins; D014157:Transcription Factors; D000097577:Homeobox Protein PITX2