Correlation Study Of Tfh Cell Proportion And Intracellular IL-21 Content In Peripheral Blood With Retinal Damage Caused By Blue Light

Objective:To investigate the correlation between the proportion of peripheral blood follicular T helper cells(Tfh cells)and intracellular IL-21 content and blue light retinal injury.Methods:1)Light damage model of retina in Brown Norway(BN)rats was established by whole body irradiation with blue light.HE staining and immunohistochemical staining were used to observe and analyze the thickness of retinal outer nuclear layer and the expression of related indexes of retinal apoptosis to verify the successful modeling.2)Brown Norway(BN)rats were randomly divided into 4 groups:control group,3 day illumination group,7 day illumination group and 14 day illumination group.The rats were exposed to LED blue light with a light intensity of(3000±100)Lux for 3 hours/day.Each group was exposed to continuous light for Od,3d,7d and 14d,respectively.The proportion of Tfli cells in peripheral blood of rats in each group was detected by flow cytometry,and the content of interleukin-21(IL-21)in Tfh cells of rats in each group was detected by Cell stimulation breaks membranes and Elisa.Retinal electroencephalography(ERG)was performed 5 days after the end of light to evaluate retinal function,fundus photography was performed to observe the changes of fundus after light,and immunohistochemical staining was performed to observe the apoptosis of retinal cells in rats.Results:1)Compared with the control group,the retinal damage caused by blue light for 3 days was manifested as the thinning of the outer nuclear layer of the retina and the increase of apoptotic cells in the retina,the difference was statistically significant;2)After the occurrence of retinal blue light damage,the proportion of Tfh cells in peripheral blood and intracellular IL-21 content increased,and the proportion of Tfh cells in peripheral blood and intracellular IL-21 content increased with the extension of light exposure time,with statistical significance.After the occurrence of retinal blue light damage,ERG showed that retinal function was decreased,light duration was prolonged,and the damage was aggravated,and the difference was statistically significant.Depigmentation changes appeared in the fundus of rats at 3 days of illumination and retinal vessels became thinner and exudate changes appeared after prolonged illumination time.Immunohistochemical staining showed that the expression of anti-apoptotic factor Bcl-2 decreased and the expression of apoptotic factor BAX increased with the extension of illumination time,and the difference was statistically significant.After blue light irradiation,ONL thickness and B-wave amplitude were negatively correlated with Tfh cell proportion in peripheral blood and its intracellular IL-21 content,while the changes at the peak of b wave were positively correlated with Tfh cell proportion in peripheral blood and its intracellular IL-21 content.The peripheral Tfh cell proportion and its intracellular IL-21 content could jointly reflect the degree of injury.Conclusion:The proportion of Tfh cells in peripheral blood and the intracellular IL-21 content were correlated with the degree of retinal blue light damage after 3 hours of LED blue light intensity of(3000±100)Lux was continuously irradiated in rats for 3 days.With the occurrence of retinal blue light damage,the proportion of peripheral blood Tfh cells and the intracellular IL-21 content were significantly increased,and increased with the aggravation of retinal blue light damage.With the extension of light duration,retinal blue light damage was aggravated,and the contents of peripheral blood Tfh cells and intracellular IL-21 were increased.Therefore,it can be speculated that the contents of peripheral blood Tfh cells and intracellular IL-21 may be an indicator to reflect the existence and degree of retinal blue light damage.Clinical medical workers can choose to use this method together with fundus examination to understand whether there is retinal blue light damage and its degree in fishermen,seafarers and other people,and take appropriate preventive measures if necessary,such as wearing anti-blue glasses.