Dermal Of Artificial Skin Photo-damage Model Study

Objective The dose of UVA1 was screened to explore the establishment of dermal of artificial skin photo-damage model,then providing a theoretical basis to pathogenesis of skin photo-damage and screening of anti- photo-damage drug.Method 1.Histology staining,immunostainging of cytokeratin 10 and fibronectin were applied to measure differentiation and secretion activity of artificial skin so as to identified the artificial skin.2.After different dose of UVA1 exposure(0J/cm~2-80J/cm~2),the number of changes of dermal fibroblasts was observed from the morphology by histology staining and immunostainging of vimentin,and dermal fibroblasts activity were measured by the MTT assay..3.The secretion of MMP-1 after different doses of UVA1 exposure(0J/cm~2-90J/cm~2) was measured using ELISA assay.Results 1.In histological sections,artificial skin displiays a fully differentiated epidermis,and fibroblasts uniform distributioned in the dermal equivalent. immunohistochemistry revealed keratin-10 and fibronectin were expressed positive in the artificial skin.2.Histology staining and immunohistochemistry showed that major alterations of the number of dermis fibroblasts were observed within the superficial part of dermal equivalent,and inversely of the UVA1 dose.MTT assay showed that there was no obvious depression of fibroblast activity in group 20J/cm~2 and group 30J/cm~2 (P＞0.05) after UVA1 exposure.Fibroblast activity was decreased obviously (P＜0.05,P＜0.001) when the dosage more than 40 J/cm~2,and this change appeared dose-dependent.3.ELISA assay of MMP-1 showed that there was no significant difference of MMP-1 secretion in group 10J/cm~2(P＞0.05) which is compared with group 0J/cm~2.A higher UVA1 dose of 20J/cm~2 was delivered which induced an increase in the level of MMP-1(P＜0.05,P＜0.0001),so as to lower UVA1 dose of 50J/cm~2.But the secretion of MMP-1 was decreased when the dosage up to 70J/cm~2 which they still had statistical significance when they compared with non-irradiation group.Conelusion UVA1 irradiations dose higher than 40J/cm~2 leads to changes including the number and the activity of dermal fibroblasts significantly reduced and an increase MMP-1 secretion obviously in artificial skin.This results showed that dermal of artificial skin photo-damage model has been established successfully.