A Preliminary Study On The Influence Of LPS-induced Cell Damage On Sialic Acid Of Cell Surface

A large number of studies have indicated that sialic acid is an important sugarsubstance, which is at the end of the glycoconjugates of the cell surface. It plays animportant role in cell adhesion, identification, inflammation and metastasis of tumorcells. Sialic acid on the surface of vascular endothelial cell is related to theoccurrence and development of cardiovascular disease, cancer and other diseases.Therefore, study of sialic acid of the cell surface and its mechanism will be of greatsignificance in the functional study of sialic acid and sialic acid glycosyltransferase.In this research, we established vascular endothelial cell damage model usingthe LPS-induced cell damage. And on this basis, we used SNA and MAA lectins torealize the fluorescence labeling for the sialic acid of the cell, and used flowcytometry and laser scanning confocal microscope to analyze the expressionchanges of its surface sialic acid after cell damage. The results showed thattreatment of1-10μg/mL LPS could cause part of the cell damage. The streamingresults of SNA bonding with sialic acid showed that when treated with LPS for4h,the contents of α-2,6sialic acids decreased slightly, of which the fluorescenceintensity in10μg/mL LPS-treated group decreased31%than in the control group.When treated with LPS for24h, the contents of α-2,6sialic acids increasedsignificantly, of which the fluorescence intensity in10μg/mL LPS-treated groupincreased119%than in the control group. The results were consistent with theconfocal laser results of SNA staining. The streaming results of MAA bonding withsialic acid showed that when treated with LPS for4h, the contents of α-2,3sialicacids also decreased slightly, of which the fluorescence intensity in1μg/mLLPS-treated group decreased42%. When treated with LPS for24h, the fluorescenceintensity in10μg/mL LPS-treated group increased37%than in the control group.The results were consistent with the confocal laser results of MAA staining.When we obtained the sialic acid changes of the cell surface after the celldamage, we preliminaryly studied the changes of sialic acid glycosyltransferases.Results of qRT-PCR showed that, expressions of ST3-1, ST3-4, and ST6-1were allchanged after LPS treating of the cells, which suggested that expressions of α-2,3connected sialic acids may be related to ST3-4, α-2,6connected sialic acids may berelated to ST6-1.In this study, by using LPS-induced cell damage, we found the change rule ofsialic acid of the cell surface and preliminarily analyzed the molecular mechanismof the change of sialic acid. The result laid the foundation of researching the relationship between sialic acid and vascular endothelial cell injury, and alsoprovided the foundation to further understand the functions of sialic acid andsialyltransferase in cell activity.