Study On The Effect Of Sargassum Fusiforme Polysaccharide On The Repair Of Damaged Skin Barrier Function

The epidermis is mainly composed of keratinocytes.The keratinocytes located in the basal layer migrate upward and gradually differentiate and mature after mitosis,forming spinous layer,granular layer and cuticle located in the outermost layer of the epidermis in turn.The cuticle of epidermis is very important to maintain the function of skin barrier.Skin aging,wound,atopic dermatitis and so on all have the damage of skin barrier function.Regulating the proliferation,migration and differentiation of keratinocytes is closely related to the recovery of skin barrier function.Sargassum fusiforme polysaccharide is a water-soluble polysaccharide extracted from Sargassum fusiforme,which has many biological activities,such as anti-aging,anti-oxidation,immune regulation and so on.At present,it has been reported that Sargassum fusiforme polysaccharide has a strong UV protection,so it has a potential application prospect in the pharmaceutical and cosmetics industry.Therefore,whether Sargassum fusiforme polysaccharide can promote the repair of damaged skin barrier is worthy of further study.Based on this,this study explored the effect of Sargassum fusiforme polysaccharide on the proliferation,migration and differentiation of keratinocytes and its mechanism,and evaluated the effect of Sargassum fusiforme polysaccharide in vivo by using the model of skin barrier dysfunction in mice.The purpose of this study is to provide a theoretical basis for its application in epidermal barrier repair.Method:1.The effects of SFPS and Sargassum fusiforme Fucoidan(SFF)on the proliferation of Ha Ca T cells were detected by CCK 8 assay and Brdu assay.2.The effects of SFPS and SFF on the m RNA expression of differentiation marker genes such as Involucrin,Filaggrin and Caspase-14 were detected by q PCR.3.The effects of SFPS and SFF on the migration of Ha Ca T cells were detected by cell scratch assay in vitro.4.The activation of MAPK pathway by SFF was detected by Western blot.5.The model of skin barrier injury in mice was established by adhesive tape method,and the repair effect of SFF on damaged skin barrier was evaluated.Method:Results: 1.The results of CCK8 assay showed that SFF treatment of Ha Ca T cells for 24 h could significantly promote the proliferation of Ha Ca T cells in a dose-dependent manner in the range of 5 ? g/ml and 20 ? g/ml.At the same time,SFPS could also significantly promote the proliferation of Ha Ca T cells at the concentrations of 10,20,50 ? g/ml.2.The results of Brdu assay showed that SFPS and SFF could promote the proliferation of Ha Ca T cells in a dose-dependent manner in the range of 5-50 ? g/ml.3.q PCR results showed that SFPS and SFF could up-regulate the expression of keratinocyte differentiation marker genes such as Involucrin,Filaggrin and Caspase-14 in a certain concentration and time range.4.The results of scratch assay showed that SFPS could promote the migration of Ha Ca T cells in a dose-dependent manner in the range of 2.5 ?g/ml and 20 ?g/ml,and SFF could promote the migration of Ha Ca T cells at lower concentrations(2.5 ?g/ml and 5?g/ml).However,at higher concentrations(10 ?g/ml and 20 ?g/ml),there was no activity to promote the migration of Ha Ca T cells.5.The results of Western Blot showed that SFF could activate ERK and JNK pathways and increase the phosphorylation levels of ERK and JNK,but had no effect on the activation of P38 pathway.SCH772984 and SP600125,specific inhibitors of ERK and JNK pathways,could block the activation of ERK and JNK pathways by SFF.6.After Ha Ca T cells were incubated with ERK and JNK specific inhibitors with SFF respectively,the effects of SFF on the proliferation,migration and differentiation of Ha Ca T cells were detected.The results showed that SCH772984,an inhibitor of ERK pathway,could inhibit the effect of SFF on the differentiation and migration of Ha Ca T cells.However,it had no significant effect on the proliferation of Ha Ca T promoted by SFF,and the inhibitor of JNK pathway could inhibit the effect of SFF on the proliferation and migration of Ha Ca T cells,but had no effect on the effect of SFF on the differentiation of Ha Ca T.7.The results of in vivo experiments showed that the adhesive tape method could cause skin barrier damage in mice,and 10% SFF hydrogel preparation could accelerate the recovery of skin barrier by smearing the damaged area of skin barrier every day.At the same time,it can effectively alleviate the pathological symptoms after skin barrier dysfunction and prevent the thickening of epidermis after skin barrier injury.Applying 10% SFF hydrogel preparation to the back skin area of normal mice can improve the hydration degree of mouse skin to a certain extent.Conclusion: The effects of Sargassum fusiforme polysaccharide on proliferation,migration and differentiation of keratinocytes and skin barrier function were studied.It was found that SFPS and SFF could promote theproliferation,migration and differentiation of Ha Ca T cells.It was proved that the proliferation,migration and differentiation of Ha Ca T cells promoted by SFF were related to the activation of ERK and JNK pathways,and the efficacy of SFF in vivo was evaluated by using the mouse model of skin barrier dysfunction.It was found that local external application of SFF could accelerate the repair of skin barrier.These studies provide a basis for the development of Sargassum fusiforme polysaccharide into the prevention and treatment of diseases related to the impairment of skin barrier function.