Bone Marrow Mesenchymal Stem Cells Accelerated Experimental Study Of Skin Wound Epithelialization

Abstract:Objective:Establishing animal models of swine full-thickness skin wounds compare that Bone marrow mesenchymal stem cells whether can promote wound healing and facilitate epithelialization under particle skin or small skin grafts environment, and discuss the possible mechanism. Thus provides new therapy ideas and methods for clinical repairing of skin defect.Method:A male and female Diannan small-ear pig,two swines(Supplied by the Experimental Animal Center of Kunming Medical College, experimental animals permit number SYXK2005-004), Taking the bone marrow is haven density gradient centrifugation to extract BM-MSCs and cell culturing in vitro.Then amplify and purify the BM-MSCs to prepare for use 3--5 generation of cells were cultured. A total of 48 wounds, there are 12 full-thickness skin on each side of each pig spinal, also in the each experimental group and control group. Experimental group:A:Autologous transplantation of particulate skin+BM-MSCs+allogeneic skin; B:Autologous transplantation of small skin graft+BM-MSCs;C:BM-MSCs+allogeneic skin transplantation. Control group:a:Autologous transplantation of particulate skin+ allogeneic skin; b:a small skin graft from the body; c:PBS+allogeneic skin transplantation.The 7th day after surgery,14th day drawn from wounding, do histopathology to evaluate its histopathological classification,immunohistochemistry to staining Ki67,pan cytokeratin (CKp), real-time PCR detection to analyze the expression level of TGF-β1 mRNA,KGF-1 mRNA.Result:Histopathology survey found that after the 7th & thel4th day of surgery, compared to the control group (a, b group),the experimental group (A, B group) was better than the control group which has the statistically significant differences from the level of wound healing of the histopathology evaluation(P<0.05). Ki67 immunohistochemical staining showed that after the 7th & the14th day of surgery, the epidermal basal cell proliferation activity of the experimental group (A, B group) is higher than the control group (a, b group).Pan keratin (CKp) immunohistochemical staining showed that the 14 days of surgery, Pure mesenchymal stem cells transplantation group of experimental group (C group) were found the wound CKp positive cells.Real-time PCR test results suggest that the expression level of TGF-β1mRNA experimental group (A, B, C group) compared with the control group (a, b, c group) was significantly decreased(P<0.05) 7 days following the operation; the 14 days expression of the experimental group and control group, no significant statistical difference (P> 0.05).KGFmRNA expression of the experimental group was significantly higher than the control group (P<0.05) 7 days after operation;the 14 days, there had no significant statistical difference of the experimental group than in the control group (P> 0.05).Conclusion:1,BM-MSCs transplant can promote survival of particles skin and small skin grafts, facilitate epithelialization of full-thickness skin defect,then accelerate wound healing.2,under the role of microenvironment of the wound of particles skin tissue and small skin, BM-MSCs transplanted to the wound regulate secretion of cytokines TGF-β1,KGF-1 and so on, which relates with involving in regulation and control of wound accelerating the propagation of these cells.3,According to requirement of the wound repairing, can differentiate into epithelial cells and so on,then involving in wound healing.