Identification And Function Of Fetal Dermal-derived Stem Cells

Background:Stem cell transplantation or tissue engineering of skin has become a promising research direction for repairing severe skin defects and refractory wounds.Among the cell types used for cell transplantation or skin tissue engineering,mesenchymal stem cells(MSCs),including adipose mesenchymal stem cells(ADSCs)and bone marrow mesenchymal stem cells(BMSCs),are the most studied cell types.However,due to the certain immunogenics of MSCs,it is generally used for autologous use.In addition,the proportion of MSCs in tissues is generally small,so MSCs are limited by the source of tissue extracted from cells.Fetal tissues sources of stem cells,theoretically has lower immunogenicity and stronger ability of proliferation and differentiation,there is more hope for,reduce the risk of immune rejection caused by cells of allografts and more suitable for the allografts,at the same time in the short term can provide sufficient source of cells for cell therapy,and therefore has a unique advantage and potential of research.In this study,Stem Cells from human Fetal skin were extracted and named as Fetal Dermal-derived Stem Cells(FDSCs),to preliminarily investigate whether the cells have the effect of promoting wound healing in full-thickness skin defect wounds of nude mice,and to identify the cells and detect their proliferation and migration.Therefore,experimental evidence is provided for the application of FDSCs in the treatment of wounds or the use of FDSCs as seed cells for tissue engineering skin.Objective:1.The effect of FDSCs on promoting wound healing was studied through the full-thickness skin defect wound model of nude mice;2.FDSCs were identified through the detection of cell morphology,surface markers and differentiation induction experiments,and whether they were mesenchymal stem cells was analyzed.3.The proliferation and migration of ADSCs and HFF-1,which are the most widely studied in wound treatment,were compared and analyzed to study whether FDSCs have better function of wound repair.Methods:1.Back in nude mice for 1.2 cm full-thickness skin defect wound model,the experimental group in defect edge along the subcutaneous injection of different doses FDSCs,control group injected cells culture medium and do not do any processing of ck,respectively in 0,3,7,10,14 days to observe the pictures and compare different groups of wound healing rate,and skin specimen for pathological detection analysis.2.The three kinds of cells were cultured and the cell morphology was observed.Flow cytometry was used to detect the expression of the related surface markers of the three kinds of cells,and the adipogenic and osteogenic differentiation of the three kinds of cells was further induced,so as to identify whether FDSCs were a kind of mesenchymal stem cells.3.CFSE staining was used to stain FDSCs,ADSCs and HFF-1 at the same time.After a period of culture,the relative proliferation rate of the three cells was calculated by fluorescence expression level.Three kinds of cells were cultured simultaneously with a six-well culture plate,and the migration rates of the three kinds of cells were compared by scratch experiment.Results:1.Compared with the control group,the cell injection group and the cell medium injection group showed higher wound healing rate at 3,7,10 and 14 days,and the wound healing rate increased significantly in the medium(5x10~6)and high(1x10~7)dose cell injection groups,and the results were statistically significant.Pathological results showed that FDSCs injection group increased dermal thickness,increased skin reepithelialization.2.There was no significant difference in the cell morphology of FDSCs,ADSCs and HFF-1,and all of them were long fusiform and typical fibroblast like morphology.The detection of cell surface markers showed that all three cells expressed MSCS-related surface markers,namely CD44,CD73,CD90 and CD105,and the expression percentage was over 90%.The hematopoietic cell related markers CD14,CD45 and CD34 were negative.All three types of HLA-DR cells were negatively expressed,but the expression percentage of FDSCs was lower than that of ADSCs and HFF-1.Further induction and differentiation experiments showed that both FDSCs and ADSCs could differentiate into adipocytes and osteocytes,while HFF-1 showed no obvious differentiation.3.The proliferation rate and migration rate of three kinds of cells were detected,and the results showed that FDSCs were the fastest,HFF-1 was the second,and ADSCs was the slowest.Conclusion:1.Fetal dermal-derived stem cells can accelerate the healing of full-thickness skin defects in nude mice,and the medium-dose and high-dose groups showed significant promoting healing effect.2.Fetal dermal derived stem cells may be a kind of fetal skin mesenchymal stem cells.3.Compared with HFF-1 and ADSCs,fetal dermal-derived stem cells proliferate and migrate faster,and may have stronger function of wound repair.