title: Epigallocatechin-3-gallate prevents heat shock-induced MMP-1 expression by inhibiting AP-1 activity in human dermal fibroblasts.
abstract: The anti-skin aging effects of epigallocatechin-3-gallate (EGCG) have been studied extensively in vitro and in vivo models. Accumulating data suggest that EGCG possesses important antioxidant and photoprotective properties. Our previous study demonstrated that heat exposure induces cutaneous angiogenesis and inflammatory cellular infiltration, disrupts the dermal extracellular matrix by inducing matrix metalloproteinases, and alters dermal structural proteins, thereby causing premature skin aging. In the present study, we examined whether EGCG may inhibit expression of MMP-1 in heat-stimulated human dermal fibroblasts. Furthermore, we investigated the inhibitory mechanism of EGCG on heat-induced MMP-1 expression. Western blot analysis and MMP-1 promoter assay revealed that EGCG markedly inhibited heat shock-induced MMP-1 expression in human dermal fibroblasts. In addition, we found that heat shock increased AP-1 DNA binding activity, and c-Jun was found to be increased mostly by heat stimulation in a supershift assay, which were suppressed by EGCG treatment. Also, in Western blotting, EGCG significantly inhibited the heat-induced expression of AP-1 constituent proteins, c-Jun, JunB and c-Fos. These results demonstrated that EGCG has abilities to inhibit heat-induced collagenolytic MMP-1 production via interfering with AP-1 pathways. Therefore, we propose that EGCG may be a potential agent for the prevention and treatment for heat shock-induced skin aging (thermal skin aging).
authors.affiliation: Department of Dermatology, Seoul National University College of Medicine, 28-Yeongeon-dong, Jongno-gu, Seoul 110-744, Korea.
authors.forename: Ji Eun
authors.initials: JE
authors.lastname: Kim
authors.forename: Mi Hee
authors.initials: MH
authors.lastname: Shin
authors.forename: Jin Ho
authors.initials: JH
authors.lastname: Chung
mesh_terms: D019588:Aging, Premature / Q000188:drug therapy / Q000378:metabolism* / Q000473:pathology; D000818:Animals; D002392:Catechin / Q000031:analogs & derivatives / Q000494:pharmacology; D020405:Dermis / Q000473:pathology; D005347:Fibroblasts / Q000187:drug effects / Q000378:metabolism / Q000473:pathology; D005786:Gene Expression Regulation / Q000187:drug effects; D006358:Hot Temperature / Q000009:adverse effects; D006801:Humans; D048031:JNK Mitogen-Activated Protein Kinases; D020781:Matrix Metalloproteinase 1 / Q000235:genetics / Q000378:metabolism*; D051379:Mice; D041681:NIH 3T3 Cells; D011485:Protein Binding; D015398:Signal Transduction; D015595:Skin Aging / Q000187:drug effects; D018808:Transcription Factor AP-1 / Q000235:genetics / Q000378:metabolism* / Q000494:pharmacology
chemical_list: D018808:Transcription Factor AP-1; D002392:Catechin; C045651:epigallocatechin gallate; D048031:JNK Mitogen-Activated Protein Kinases; D020781:Matrix Metalloproteinase 1