Study On The Effect Of Egg White Source Small Peptides On Skin Cell Migration

Egg white is an ideal protein source to generate food-derived peptides.It has been proved that egg white peptides have various bioactivities such as anti-thrombosis,antiinflammation,anti-oxidation and anti-virus.However,few studies have focused on its promoting cell migration and skin wound healing functions.In this research,we hydrolyzed egg white powder and separated the hydrolysate with ultrafiltration and sephadex column.We analyzed the peptide mixture using LC-MS and identified the sequences of the bioactive peptides.We also use cell and animal models to study the activities of these egg white peptides on promoting cell migration and wound healing both in vitro and in vivo.Our research procedures and results are listed as below.Firstly,we hydrolyzed the egg white powder with Alcalase and flavourzyme sequentially.We ultra-filtrated the hydrolysate using the 1kDa ultrafiltration membrane.We tested the filtrate,which consists of egg white peptides under 1000 molecule weight,using human HaCaT cell as the cell model.Our scratch wound healing and transwell data showed that these small molecular egg white peptides promoted HaCaT cell migration.We then separated the filtrate with Sephadex G-15 column and obtained four groups of peptides mixtures,which are named as S1 to S4.We tested these four groups of peptides using transwell assay.Our data showed that S2 peptides dramatically promoted cell migration.We analyzed the peptides sequences in S2 using LC-MS and identified 22 peptide sequences with high abundance.We randomly chose and synthesized six of these peptides,and tested them on HaCaT cells.We found two peptides LAYEER and LRDILN promoted HaCaT cell migration.In addition,LRDILN showed better migration promoting activity than LAYEER.Therefore,we chose LRDILN to further explored its activity on the mouse skin wound model.We cut a 7mm diameter circular wound on the back of each mouse.We dissolved LRDILN in normal saline and applied the solution to the mice wounds.After ten days applying,our data showed that LRDILN dramatically accelerated mice skin wound healing compared with control group.We cut the wound edge tissues every two days to perform HE staining.Our data suggested that LRDILN treatment group had more and well-ordered keratinocytes on the wound edges,which are benefit for skin wound healing.In this research,we proved egg white peptide LRDILN promoted skin keratinocytes migration and accelerating mouse wound healing for the first time.These findings provide a theoretical proof of developing novel egg white peptides agents to promote skin wound healing.