title: Nfkbiz regulates the proliferation and differentiation of keratinocytes.
abstract: Nuclear factor of kappa light polypeptide gene enhancer in B cells (NF-κB) inhibitor zeta (Nfkbiz) is a nuclear inhibitor of NF-κB (IκB) protein that is also termed as molecule possessing ankyrin repeats induced by lipopolysaccharide, interleukin-1-inducible nuclear ankyrin repeat protein, or IκBζ. We found previously that disrupting the Nfkbiz gene resulted in atopic dermatitis-like lesions in mice, suggesting an important role for Nfkbiz in the skin. In this study, we examined the cellular function of Nfkbiz in keratinocytes. Immunohistochemical analyses for Ki-67 revealed that Nfkbiz-/- keratinocytes were hypoproliferative. In skin from Nfkbiz-/- mice, the expression of the keratinocyte differentiation markers K10 and filaggrin were reduced, although that of K14 was unchanged. The terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling assay revealed that the frequency of apoptosis was comparable between control and Nfkbiz-/- keratinocytes. Interestingly, the subcellular localization of the NF-κB subunits and the transcriptional activity of NF-κB were not changed in Nfkbiz-/- keratinocytes. These findings indicate a novel possible role of Nfkbiz in controlling the proliferation and differentiation of epidermal keratinocytes through NF-κB-independent mechanisms.
authors.forename: Toshina
authors.initials: T
authors.lastname: Ishiguro-Oonuma
authors.forename: Kazuhiko
authors.initials: K
authors.lastname: Ochiai
authors.forename: Kazuyoshi
authors.initials: K
authors.lastname: Hashizume
authors.forename: Toshihiko
authors.initials: T
authors.lastname: Iwanaga
authors.forename: Masami
authors.initials: M
authors.lastname: Morimatsu
mesh_terms: D048868:Adaptor Proteins, Signal Transducing / Q000235:genetics / Q000378:metabolism*; D000818:Animals; D002454:Cell Differentiation / Q000235:genetics*; D049109:Cell Proliferation; D000078404:Epidermal Cells; D004817:Epidermis / Q000502:physiology*; D005786:Gene Expression Regulation; D007150:Immunohistochemistry; D015603:Keratinocytes / Q000502:physiology*; D051379:Mice; D009687:Nuclear Proteins / Q000235:genetics / Q000378:metabolism*
chemical_list: D048868:Adaptor Proteins, Signal Transducing; C485947:Nfkbiz protein, mouse; D009687:Nuclear Proteins