The Role Of Nesprin 2 In The Process Of The Transformation Of Normal Skin Fibroblasts To Hypertrophic Scar Fibroblasts Caused By Mechanical Stretch

Objective To explore the role of nesprin 2 in the process of the transformation of normal skin fibroblasts to hypertrophic scar fibroblasts caused by mechanical stretch.Methods The dermal fibroblasts of normal skin were isolated and cultured in vitro by tissue block method,and the 4-6 generation cells were taken for experiment.The cells were divided into two groups that inhibited the expression of nesprin 2 and did not inhibit the expression of nesprin 2.The cells that inhibited the expression of nesprin2 were transfected to siRNA by liposome transfection,and the cells without interference with the nesprin 2 gene were transfected to siRNA negative controls to determine the homology of the other genes in the target cells.The normal cultured fibroblasts and fibroblasts after nesprin 2 RNA interference,were set up in the experimental group and the control group respectively,at a total of 4 groups.Experimental groups were loaded with 0.1Hz,10%amplitude cyclic stretch for 3 days.Control group were cultured without cyclic stretch.At the end of experiments,the cells in each group were tested according to the following index:cell morphology was observed under inverted microscope;ELISA method was used to detect the content of type I collagen and TGF-β₁ in culture supernatant;SYBR Green qPCR method was used to detect the mRNA level of nesprin2、α-smooth muscle actin（α-SMA）、transform growth factorβ₁（TGF-β₁）and collagen type I;Western-Blot method was used to detect the content of protein laminA+C、α-SMA.Results The expression level of nesprin2 and laminA+C of the experimental group and control group which were interfered with nesprin2 gene are lower than that of the experimental group and control group which were not interfered with nesprin2 gene,which showed significant differences（P<0.05）.When loaded for 3 days with amplitude cyclic stretch,the expression levels ofα-SMA,TGF-β₁,type I collagen of the experimental group which were interfered with nesprin2 gene are under that of the experimental group which were not interfered with nesprin2 gene,which showed significant differences（P<0.05）.When loaded for 3 days with amplitude cyclic stretch,the expression levels ofα-SMA,TGF-β₁,type I collagen of the experimental group which were interfered with nesprin2gene are higher than that of the control group which were interfered with nesprin2 gene,which showed significant differences（P<0.05）.Conclusion（1）Mechanical stretch can increase the expression ofα-SMA,TGF-β₁,type I collagen,which can promote the transformation of normal skin fibroblasts into hypertrophic scar fibroblasts;（2）The interference of nesprin 2 gene can inhibit the improvement of the expression levels ofα-SMA,TGF-β1,type I collagen which mechanical stretch lead to,thereby inhibiting the transformation process of normal skin fibroblasts to hypertrophic scar fibroblasts under mechanical stretch.（3）Nesprin 2,to a certain extent,affects the degree of the transformation of normal skin fibroblasts to hypertrophic scar fibroblasts in the process of mechanical stretch.