Study On The Effect Of HADSCs That Overexpressed Homo Thymosin ?-4 Gene Combined With Sheep Acellular Dermal Matrix On Wound Healing

Skin defect is one of the most common diseases in clinic.Large area skin defect can seriously affect human health even threaten person's life.Previous studies of wound repair have shown that cell therapy has a positive effect on the process of skin repair and small peptide thymosin ?-4(T?4)can promote the course of wound healing by secreting anti-inflammatory factors.Acellular Dermal Matrix(ADM)which treated by freeze-dried can be used as a good cell scaffold for cell transplantation.Therefore,in order to improve the efficiency of wound healing,in this study,we mainly investigated the effects of human Adipose-derived Mesenchymal Stem Cells(hADSCs)that overexpressed homo T?4 gene combined with sheep ADM on wound healing.First of all,in this study,abandoned adipose tissues from patients whom undergoing surgery were used as experimental material,then digested by collagenase,we acquired our target cells.By detecting of stem cells-related features,we confirmed the isolated cells are hADSCs.Then,the plasmid p EX4-hT?4that containing h T?4 gene was transfected into hADSCs by electroporation.Detected by RT-qPCR and Western Blot,the results showed that: the expression of hT?4 geneand protein in hADSCs which overexpressed h T?4 gene was significantly increased.Secondly,by the method of enzyme digestion,the sheep ADM was prepared.The cytotoxic of ADM was detected by MTS and the results show that ADM has no cytotoxic effect on the target cells.Finally,the ADM that combined with hADSCs which overexpressed hT?4 gene and the ADM that combined with hADSCs were respectively covered on full-thickness skin wounds of nude mice.Then extracted of wound tissues of mude mice on 7,14 and 21 days,respectively.The HE staining and the distribution of neovascularization in the wound tissue were observed,and the expression of apoptosis genes,wound healing-related genes and proteins were detected by RT-qPCR and western blot.The results showed that: with the increase of healing time,the expression levels of wound healing-related genes VEGF and Collagen I were significantly decreased,and the expression levels of CK18 and Collagen III were significantly increased.At the same time,the hADSCs overexpressed of hT?4 gene compound with sheep ADM were significantly improved wound healing rate,reduced apoptosis of cells,and promoted the expression of wound healing-related genes and proteins.This study preliminarily discussed the effect of hADSCs that overexpressed hT?4 gene compound with sheep ADM on wound healing,and it will provide a basis for further research on the mechanism of wound healing.