Preliminary Study On The Protective Effect Of Melanin Granules Secreted By Melanin Cells On UVB-mediated Keratinocyte Photodamage

Objective:To investigate the photoprotective effect of melanin granules secreted by melanin cells cultured in vitro on keratinocytes.Methods:1.For the in vitro culture of melanocyte medium the melanin granules was extracted using the enzyme digestion method extract melanin cells from normal skin tissues and cutin cell formation,the separation of the melanin cell in vitro culture represented,the microscopic observation secretion of melanin granules,adopt the method of filtering and overspeed centrifugal will melanin granules and purification and spectrophotometer were used to detect the absorbance.2.To explore whether melanin particles could be phagocytosed by keratinocytes and Ha Ca T cells,purified melanin particles were added into keratinocytes and Ha Ca T cells respectively,and the phagocytosis was observed by Fontana-Masson staining.3.In order to establish u VB-mediated photodamage model of keratinocytes,the relationship between different irradiation intensity,dose and detection time after irradiation was compared.Heochst3334220 staining,image J counting and CCK-8 were used to detect cell proliferation activity.4.In order to study the photoprotective effect of melanin granules on keratinocytes,q PCR was used to detect the expression of dry genes and differentiated genes in keratinocytes5.SPSS 24.0 software was used for statistical analysis.Results:1.Melanocytes and keratinocytes were successfully isolated from normal skin tissue,and melanin granules were isolated from melanocyte culture medium and purified.2.Fontana-masson staining of keratinocytes and Ha Ca T cells with added melanin granules showed that the melanin granules could be phagocytosed by keratinocytes and Ha Ca T cells and reside around the nucleus.3.The uv damage conditions(irradiation intensity: 1m W/cm2,irradiation distance: 15 cm,irradiation time: 240 s,dose: 240 m J/cm2,detection time after irradiation: 18h)were determined,and the UVB-mediated keratinocyte light injury model was successfully established.4.The proliferation ability of keratinocytes exposed to UVB irradiation was studied.It was found that the proliferation activity of keratinocytes phagocytic melanin granules increased,and melanin granules inhibited the expression of keratinocyte differentiation genes.Conclusion:1.Melanocytes cultured in vitro could secrete melanin granules into their culture medium.It can be extracted and purified by centrifugal filtration.2.The melanin granules can be swallowed by keratinocytes and reside around the nucleus.3.UVB mediated photodamage model of keratinocytes was successfully established and applied in subsequent experiments.4.The UVB protective effect of keratinocytes phagocytic melanin granules was preliminarilly explored.Melanin granules can promote the proliferation activity of keratinocytes and inhibit the differentiation of keratinocytes by UVB.