Induction of matrix metalloproteinase-9 secretion from human keratinocytes in culture by ultraviolet B irradiation.
BACKGROUND
Matrix metalloproteinases (MMPs) are known as important enzymes involved in tissue metabolism. Among them, MMP-2 and MMP-9 are termed gelatinases, but their specific roles in vivo are still unknown, including their expression patterns following ultraviolet (UV) irradiation.


OBJECTIVE
To elucidate the effects of UV irradiation on the skin, we analyzed the expression of MMP-2 and MMP-9 by primary human keratinocytes in culture.


METHODS
We evaluated the enzymatic functions of MMP-2 and MMP-9 by gelatin-zymography, and of MMP-9 expression by immunofluorescence, using cultured keratinocytes after UV irradiation.


RESULTS
The secretion of MMP-2 (72 kDa) remained at low levels under all conditions examined. Although MMP-9 (92 kDa) secretion was not induced by UVA, it was stimulated by UVB irradiation in a dose-dependent manner. In addition, an enzyme-linked immunosorbent assay showed the tendency to increase for the involucrin expression following UVB exposure. Cell viability was decreased by UVB irradiation in contrast to the induction of MMP-9 and involucrin.


CONCLUSIONS
These results suggest that the induction of MMP-9 secretion is related to the inflammation including apoptosis of keratinocytes resulting from UVB irradiation.
Product Research Laboratory, KOSE Corporation, 48-18 Sakae-cho, Kita-ku, 114-0005, Tokyo, Japan. s-onoue@kose.co.jp
Satoshi
S
Onoue
Takashi
T
Kobayashi
Yuko
Y
Takemoto
Ichiro
I
Sasaki
Hiroshi
H
Shinkai
D002470:Cell Survival / Q000528:radiation effects; D002478:Cells, Cultured; D004797:Enzyme-Linked Immunosorbent Assay; D006801:Humans; D015603:Keratinocytes / Q000166:cytology / Q000201:enzymology* / Q000502:physiology / Q000528:radiation effects; D020778:Matrix Metalloproteinase 2 / Q000378:metabolism / Q000528:radiation effects; D020780:Matrix Metalloproteinase 9 / Q000378:metabolism* / Q000528:radiation effects; D014466:Ultraviolet Rays
D020778:Matrix Metalloproteinase 2; D020780:Matrix Metalloproteinase 9