Repairs Of UVB Injured HaCaT Cells By Neutral Polysaccharides In Dendrobium Officinale

When it comes to human beings' health,the excessive amount of ultraviolet radiation received by skin can easily cause the inflammation,skin aging,and even skin cancer.Ultraviolet radiation b rays(UVB)are the main cause of skin photoaging.This study built a stable model of UVB injured HaCaT cells by simulating the solar ultraviolet radiation.Besides,this study detected the neutral polysaccharides in Dendrobium officinale(NPD)repair efficacy on UVB injured HaCaT cells based on the HaCaT cells surviral rate,the activities of superoxide dismutase(SOD),catalase(CAT)and the contents of malondialdehyde(MDA)and glutathione(GSH).To analyze the UVB damaged pathway and NPD repair pathway,the study also screened differential genes by RNA Sequencing.The main research conclusions are concluded as follows:(1)It has built a stable model of UVB injured HaCaT cells.When the UVB radiation dose was 150 m J/cm2,the relative survival rate of HaCaT cells was 45.23 ± 4.65%.It has been found that 100 ?g/m L NPD had significant repair efficacy on UVB injured HaCaT cells,and the relative survival rate of HaCaT cells increased 15.17 ± 5.10%;The repair efficacy achieved the best when NPD was used immediately after radiation.(2)It has been found that NPD contributed to the increase of oxidation resistance of UVB injured HaCaT cells.After the NPD treatment,the activities of SOD,CAT(p <0.01)and the content of GSH of the injured HaCaT cells became significantly higher(p <0.01),whereas the content of MDA was significantly lower(p <0.05).Those results indicate that NPD could improve the antioxidant capacity of cells to achieve its repair effect.(3)The analysis of RNA sequencing shows that:NPD had no significant effect on the normal growth and metabolic pathway of HaCaT cells.There were 11305 differentially expressed genes screened from UVB injured HaCaT cells.Pathway analysis identified that 16 signal pathways might be related to UVB injured HaCaT cells,including TNF signaling pathway,apoptotic pathway,ECM-receptor interaction pathway,peroxisome pathway,MAPK signaling pathway,etc.After NPD repair,there were 618 differentially expressed genes screened for UVB injured HaCaT cells.Pathway analysis showed that 8 signal pathways might be related tothe NPD repaired of UVB injured HaCaT cells,including TNF signaling pathway,apoptosis pathway and Toll-like receptor signaling pathway,etc.Overall,this study built a stable model of UVB injured HaCaT cells by simulating solar ultraviolet radiation,giving insight into further research on the biological activity of DOP and other officinales,and experimental evidence for the application.Besides,UVB injury pathway and NPD repair pathway of HaCaT cells can provide possible theoretical basis for developing safe and effective cosmetics to prevent skinphotoaging.