Protective effects of Chlorella-derived peptide on UVB-induced production of MMP-1 and degradation of procollagen genes in human skin fibroblasts

UV exposure is known to induce premature aging, which is mediated by matrix metalloproteinase-1 (MMP-1) activity. MMP-1 mRNA expression is up-regulated by elevated cysteine-rich 61 (CYR61) and monocyte chemoattractant protein-1 (MCP-1) via action of transcription factor AP-1. Collagen is degraded by MMP-1 activity but synthesized by transforming growth factor-β (TGF-β) signal. Chlorella has been shown to inhibit UVB-induced MMP-1 level, however its regulatory molecular mechanisms have not been studied. In this study, Chlorella derived peptide (CDP) was added to skin fibroblasts after UVB irradiation and the expression of MMP-1, CYR61, procollagen, c-fos, c-jun, and TGF-β receptor (TbRII) mRNA and MCP-1 production were investigated. CDP (10 or 5 mg/ml) diminished UVB-induced MMP-1 and CYR61 mRNA expression and MCP-1 production, whereas, UVB-suppressed procollagen and TbRII mRNA was restored by CDP treatment. UVB-induced c-fos and c-jun expressions were also inhibited by the CDP treatment. Taken together, CDP inhibits UVB-induced MMP-1 expression in skin fibroblasts by suppressing expression of AP-1 and CYR61 and MCP-1 production.