Overexpression of phospholipid-hydroperoxide glutathione peroxidase in human dermal fibroblasts abrogates UVA irradiation-induced expression of interstitial collagenase/matrix metalloproteinase-1 by suppression of phosphatidylcholine hydroperoxide-mediated NFkappaB activation and interleukin-6 release.
Phospholipid-hydroperoxide glutathione peroxidase (PHGPx) exhibits high specific activity in reducing phosphatidylcholine hydroperoxides (PCOOHs) and thus may play a central role in protecting the skin against UV irradiation-triggered detrimental long term effects like cancer formation and premature skin aging. Here we addressed the role of PHGPx in the protection against UV irradiation-induced expression of matrix metalloproteinase-1 (MMP-1). For this purpose, we created human dermal fibroblast cell lines overexpressing human PHGPx. Overexpression led to a significant increase in PHGPx activity. In contrast to a maximal 4.5-fold induction of specific MMP-1 mRNA levels in vector-transfected cells at 24 h after UVA irradiation, no MMP-1 induction occurred at any studied time point after UVA treatment of PHGPx-overexpressing fibroblasts. As interleukin-6 (IL-6) was earlier shown to mediate the UVA induction of MMP-1, we studied whether PHGPx overexpression might interfere with the NFkappaB-mediated IL-6 induction and downstream signaling. Using transient transfections of IL-6 promoter constructs containing NFkappaB binding sites, we observed a high induction of the reporter gene luciferase in vector-transfected control cells and a significantly lower induction in PHGPx-overexpressing fibroblasts following UVA irradiation. Consistently both UVA irradiation and treatment of fibroblasts with PCOOHs led to phosphorylation and nuclear translocation of the p65 subunit, whereas cells overexpressing PHGPx exhibited impaired NFkappaB activation, p65 phosphorylation, and nuclear translocation. In line with this, the PHGPx-overexpressing fibroblasts showed a reduced constitutive and UVA irradiation-induced IL-6 release. After incubating PHGPx-overexpressing cells with PCOOHs a reduced induction of IL-6 was observed. This together with the suppression of UVA irradiation-induced IL-6 release in the presence of Trolox, a chain breaker of PCOOH-initiated lipid peroxidation, indicates that UVA irradiation-induced PCOOHs and subsequent lipid peroxides initiate the NFkappaB-mediated induction of IL-6, which mediates the induction of MMP-1. Our finding is particularly relevant in light of the already available small molecule mimetics of PHGPx.
Department of Dermatology, University of Cologne, 50924 Cologne, Germany.
Jutta
J
Wenk
Jutta
J
Schüller
Christina
C
Hinrichs
Tatjana
T
Syrovets
Ninel
N
Azoitei
Maurizio
M
Podda
Meinhard
M
Wlaschek
Peter
P
Brenneisen
Lars-A
LA
Schneider
Andrea
A
Sabiwalsky
Thorsten
T
Peters
Silke
S
Sulyok
Joachim
J
Dissemond
Matthias
M
Schauen
Thomas
T
Krieg
Thomas
T
Wirth
Thomas
T
Simmet
Karin
K
Scharffetter-Kochanek
D021581:Active Transport, Cell Nucleus; D002460:Cell Line; D017364:Collagenases / Q000235:genetics*; D005347:Fibroblasts / Q000378:metabolism / Q000528:radiation effects; D015971:Gene Expression Regulation, Enzymologic / Q000528:radiation effects*; D005979:Glutathione Peroxidase / Q000502:physiology*; D006801:Humans; D015850:Interleukin-6 / Q000096:biosynthesis*; D020781:Matrix Metalloproteinase 1 / Q000235:genetics*; D016328:NF-kappa B / Q000378:metabolism*; D010713:Phosphatidylcholines / Q000502:physiology*; D000080662:Phospholipid Hydroperoxide Glutathione Peroxidase; D012333:RNA, Messenger / Q000032:analysis; D012867:Skin / Q000166:cytology / Q000378:metabolism / Q000528:radiation effects*; D014466:Ultraviolet Rays
D015850:Interleukin-6; D016328:NF-kappa B; D010713:Phosphatidylcholines; D012333:RNA, Messenger; C057590:phosphatidylcholine hydroperoxide; D000080662:Phospholipid Hydroperoxide Glutathione Peroxidase; D005979:Glutathione Peroxidase; D017364:Collagenases; D020781:Matrix Metalloproteinase 1