Study On The Mechanism Of Egg White Peptide Promoting Gastric Ulcer Wound Healing

The gastric mucosa is a layer of mucosa that has a protective effect on the stomach.It can resist the damage of various factors to the gastric tissue.In recent years,the incidence of gastric diseases caused by gastric mucosal injury has increased year by year.Therefore,the integrity of the gastric mucosa has an important impact on the occurrence and development of gastric diseases.Gastric ulcer is a relatively common type of peptic ulcer disease.The main clinical treatment of gastric ulcer is drug therapy,but there are disadvantages such as lack of efficacy and poor patient dependence.There is urgent to develop novel drugs with good effects and low prices to treat or relieve gastric ulcers.Egg white powder polypeptide is a kind of food-derived polypeptide.Studies have shown that egg white peptide has a variety of biological activities,but there are few studies on its role in promoting cell migration and gastric ulcer wound healing.The laboratory has separated and purified egg white powder in the early stage,and analyzed its components to obtain a series of biologically active egg white powder polypeptides.On this basis,this topic studies the effect of egg white powder polypeptides on gastric ulcer wound healing from two aspects in vivo and in vitro,and further explores its mechanism.It is intended to provide scientific research basis for the development of egg white powder polypeptide as a health care drug that can effectively improve the pathological state of gastric ulcer from the perspective of nutritional treatment and homology of medicine and food.The main research contents and conclusions are as follows:Nine egg white powder polypeptides were randomly selected,and then screened the polypeptides that can promote the migration of gastric mucosa epithelial cells GES-1 by Transwell migration assay.The results showed that VVRFD,FDKLPGF,DSTRTQIN can effectively promote the migration of GES-1 cells.Subsequently,these three peptides were selected for concentration gradient experiments.The results demonstrated that both the egg white peptides VVRFD and DSTRTQIN could promote the migration of GES-1 cells within a certain concentration range.Wound Healing Assay experiments also further verified the effects of VVRFD and DSTRTQIN on the migration ability of GES-1 cells.MTS experiments showed that only the egg white powder polypeptide VVRFD could significantly promote the proliferation of GES-1 cells.Afterwards,the mechanism of VVRFD and DSTRTQIN in promoting the migration of GES-1 cells and the mechanism of affecting the proliferation of GES-1 cells were studied by Western Blot experiments.The results showed that both peptides can affect the expression of the intracellular protein Hsp90α,secrete Hsp90α to the outside of the cell through the exosome pathway,and then activate the cell surface receptor LRP-1 to transmit the pro-migration signal into the cell,thereby inducing the cell migration related signaling pathways and promote cell migration.Next,the repairing effect of egg white powder polypeptide on gastric ulcer wound was further studied by establishing an aspirin-induced gastric ulcer model in mice.Considering that both the proliferation and migration of epithelial cells in gastric ulcer can improve ulcer wounds to a certain extent,we chose egg white powder polypeptide VVRFD for follow-up research.The stomach pictures and pathological sections of gastric tissue showed that compared with the model group,the gastric bleeding points and inflammatory cell infiltration were reduced in mice treated with VVRFD,and there was less epithelial cell shedding.After that,we measured the changes of SOD and MDA content in the serum of mice,and the results showed that the activity of SOD in the high-dose VVRFD group increased,and the content of MDA decreased.This suggests that VVRFD may reduce the further aggravation and damage of ulcer wounds through antioxidant effects.Western Blot results showed that the expressions of Hsp90α and LRP-1 were increased in the early stage of ulcer healing,but the expressions of the two proteins did not change significantly in the later stage of healing.This suggests that Hsp90α may play an important role in the early stage of ulcer healing.This study showed that egg white powder polypeptides VVRFD and DSTRTQIN have pro-migration activities on GES-1 cells,and proved that the mechanism may be to promote the migration of GES-1 cells by affecting the Hsp90α-LRP-1-Akt-related signaling pathway.Among them,VVRFD promotes the migration activity of GES-1cells more significantly,and can affect the proliferation of GES-1 cells in vitro,accelerate the healing of ulcer wounds and reduce the inflammatory response in vivo,which proves that its mechanism may be in the early stage of ulcer healing,through influence Hsp90α-related signaling pathway to promote ulcer wound healing.To sum up,it shows that egg white peptide has potential application value in the treatment of gastric ulcer,and also provides a data basis for egg white powder peptide to become a new type of healing drug for the treatment of gastric ulcer.