title: Possible roles of barrier-to-autointegration factor 1 in regulation of keratinocyte differentiation and proliferation.
abstract: BACKGROUND
  Barrier-to-autointegration factor 1 (BANF1) is an essential component of the nuclear lamina. Recent studies have clarified that BANF1 is a causative molecule of Nestor-Guillermo progeria syndrome. Despite recent progress in studies on BANF1, the role of BANF1 in keratinocytes has not been addressed at all.
  
  
  OBJECTIVE
  This study aims to determine the localization of BANF1 in psoriatic epidermal keratinocytes as well as in normal keratinocytes and to clarify its possible function in those keratinocytes.
  
  
  METHODS
  Immunohistochemistry of BANF1 was performed on 10 cases of psoriasis and 10 healthy control individuals. Expression of molecules associated with inflammation of the skin by HSC-1, a human skin squamous cell carcinoma cell line, stimulated by TPA and treated with siRNA to BANF1 were analyzed with quantitative PCR and Western blot.
  
  
  RESULTS
  Strong nuclear-dominant immunostaining of BANF1 was seen in the epidermal keratinocytes of psoriatic lesions, although in the normal epidermis, all the KCs in the upper epidermis showed cytoplasmic-dominant staining of BANF1. By BANF1 knockdown in TPA-stimulated HSC-1 cells, the mRNA levels of S100A9 were significantly elevated compared with those of control HSC-1 cells treated with siRNA to CD4. The protein expression level of S100A9 and phosphorylated c-Jun was elevated by BANF1 knockdown.
  
  
  CONCLUSIONS
  BANF1 is translocated onto the nuclear envelope in the psoriatic epidermal keratinocytes, suggesting that BANF1 is associated with upregulated proliferation of keratinocytes in psoriatic lesions. Activation of BANF1 possibly suppresses S100A9 expression and inactivates c-Jun, resulting in suppression of cutaneous inflammation.
authors.affiliation: Department of Dermatology, Nagoya University Graduate School of Medicine, 65 Tsurumai-cho, Showa-ku, Nagoya 466-8550, Japan.
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Takama
authors.forename: Kazumitsu
authors.initials: K
authors.lastname: Sugiura
authors.forename: Yasushi
authors.initials: Y
authors.lastname: Ogawa
authors.forename: Yoshinao
authors.initials: Y
authors.lastname: Muro
authors.forename: Masashi
authors.initials: M
authors.lastname: Akiyama
mesh_terms: D021581:Active Transport, Cell Nucleus; D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D040502:Calgranulin B / Q000378:metabolism; D002294:Carcinoma, Squamous Cell / Q000378:metabolism; D002454:Cell Differentiation; D045744:Cell Line, Tumor; D049109:Cell Proliferation; D004268:DNA-Binding Proteins / Q000378:metabolism*; D004817:Epidermis / Q000378:metabolism; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D007150:Immunohistochemistry; D007249:Inflammation; D015603:Keratinocytes / Q000166:cytology*; D008875:Middle Aged; D009687:Nuclear Proteins / Q000378:metabolism*; D016755:Proto-Oncogene Proteins c-jun / Q000378:metabolism; D034741:RNA, Small Interfering / Q000378:metabolism; D012878:Skin Neoplasms / Q000378:metabolism; D013577:Syndrome; D055815:Young Adult
chemical_list: C501959:BANF1 protein, human; D040502:Calgranulin B; D004268:DNA-Binding Proteins; D009687:Nuclear Proteins; D016755:Proto-Oncogene Proteins c-jun; D034741:RNA, Small Interfering
keywords: AP-1; Barrier-to-autointegration factor 1; Keratinocyte; Psoriasis; S100A9