Human keratinocytes express fractalkine/CX3CL1.
BACKGROUND
fractalkine/CX3CL1 is a unique chemokine that has properties of both chemoattractants and adhesion molecules. The major source of this chemokine in the skin is still controversial.


OBJECTIVE
studies were undertaken to determine the expression of fractalkine in human skin.


METHODS
RT-PCR, Western blotting, and immunostaining were performed with normal human epidermal keratinocytes (NHEK) and HaCaT cells, human keratinocyte cell line, for the presence of fractalkine. Biopsy specimens of normal and diseased skin were also investigated.


RESULTS
we identified that NHEK and HaCaT cells expressed fractalkine mRNA and protein. The combination of tumor necrosis factor (TNF)-alpha and interferon (IFN)-gamma upregulated their expression by NHEK. Immunohistochemistry demonstrated fractalkine expression in keratinocytes in lichen planus and psoriasis vulgaris. RT-PCR also showed that lesional skin of psoriatic patients expressed higher levels of fractalkine mRNA than non-lesional skin from the same patients.


CONCLUSIONS
these results suggests that keratinocytes strongly express fractalkine in lichen planus and psoriasis vulgaris and that the fractalkine-CXC3CR1 system in the diseased skin can be a target for the treatment.
Department of Dermatology, Faculty of Medicine, University of Tokyo, 7-3-1, Hongo, Bunkyo-ku, Tokyo 113-8655, Japan, sugayam-der@h.u-tokyo.ac.jp
Makoto
M
Sugaya
Koichiro
K
Nakamura
Hiroshi
H
Mitsui
Tomonori
T
Takekoshi
Hidehisa
H
Saeki
Kunihiko
K
Tamaki
D002460:Cell Line; D054428:Chemokine CX3CL1; D020523:Chemokines, CX3C / Q000235:genetics* / Q000378:metabolism; D004730:Endothelium, Vascular / Q000378:metabolism; D006801:Humans; D007150:Immunohistochemistry; D007231:Infant, Newborn; D015603:Keratinocytes / Q000378:metabolism*; D008565:Membrane Proteins / Q000235:genetics* / Q000378:metabolism; D012333:RNA, Messenger / Q000235:genetics; D011994:Recombinant Proteins / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012867:Skin / Q000378:metabolism; D014162:Transfection; D014471:Umbilical Veins
C515538:CX3CL1 protein, human; D054428:Chemokine CX3CL1; D020523:Chemokines, CX3C; D008565:Membrane Proteins; D012333:RNA, Messenger; D011994:Recombinant Proteins