Up-regulation of keratin 17 expression in human HaCaT keratinocytes by interferon-gamma.
The immortalized human keratinocyte cell line HaCaT was used to assess the effect of interferon-gamma (IFN-gamma) on expression of keratin K17. Both IFN-gamma and K17 have been implicated in the pathophysiology of psoriasis. Western and quantitative enzyme-linked immunosorbent assay analyses demonstrated increasing induction of K17 protein by 48 h exposure to IFN-gamma at concentrations of 10, 50, and 250 U/ml. At 50 U/ml IFN-gamma, immunohistochemical analysis revealed numerous K17-positive foci, whereas in situ hybridization demonstrated K17 message in the majority of cells. In addition, at low (5 U/ml) concentrations of IFN-gamma, cell proliferation and protein synthesis decreased, as determined by 3H-thymidine labeling and 14C-amino acid uptake. These data suggest that aberrant K17 expression observed in psoriatic lesions may be a consequence of IFN-gamma overexpression, and that the HaCaT cell line may be a useful in vitro model system to elucidate the underlying mechanisms.
Bonnekoh
B
B
Department of Dermatology, University of Cologne, Germany.
Huerkamp
C
C
Wevers
A
A
Geisel
J
J
Sebök
B
B
Bange
F C
FC
Greenhalgh
D A
DA
Böttger
E C
EC
Krieg
T
T
Mahrle
G
G
D000943:Antigens, Differentiation / Q000032:analysis; D015153:Blotting, Western; D002460:Cell Line; D004797:Enzyme-Linked Immunosorbent Assay; D006801:Humans; D007371:Interferon-gamma / Q000494:pharmacology*; D015603:Keratinocytes / Q000737:chemistry*; D007633:Keratins / Q000187:drug effects / Q000235:genetics / Q000502:physiology*; D011565:Psoriasis / Q000175:diagnosis; D012333:RNA, Messenger / Q000032:analysis; D015854:Up-Regulation
D000943:Antigens, Differentiation; D012333:RNA, Messenger; D007633:Keratins; D007371:Interferon-gamma