Study Of Mechanism Of UVB-irradiated Epidermal Keratinocytes And UVA-irradiated Dermal Fibroblasts In Skin Photoaging

Human skin receptive solar UV irradiation comprises mainly UVB and UVA. One molecular mechanism of skin photoaging is that UVA and UVB induce MMPs gene transcription of epidermal keratinocytes and dermal fibroblasts through activating cellular signal transduction pathways. Skin photoaging results from the comitant effects of UVA and UVB: one side, UVA and UVB induce MMPs expression and production of epidermal keratinocytes and dermal fibroblasts which exert degradation action to dermal excellular matrix; other side, UVA induces cytokine IL-6 synthesis and production of dermal fibroblasts which promote MMPs expression of fibroblasts by themselves through autocrine mechanism. It is more important that UVB induces cytokines IL-1, TNF-α, and IL-6 synthesis and production of epidermal keratinocytes which promote MMPs expression of fibroblasts through...