Study On MMP-3 Gene Modified Stem Cells For Repairing Radiation Induced Intestinal Fibrosis

At present,the incidence of human cancer is extremely high,the current major medical treatment is radiation therapy,but for abdominal,pelvic and other body parts,this treatment will have some side effects,a certain degree of radiation will lead to radiation enteritis,subsequently trigger deposition of extracellular matrix(ECM)in the intestine,contribute to radioactive fibrosis,the occurrence and development of intestinal fibrosis seriously affect the prognosis of patients and quality of life.Matrix metalloproteinase 3(MMP-3)can degrade ECM,which is the key enzyme to remodel the tissue structure,it can repair the intestinal tissue.However,the expression of MMP-3 in the body is very limited,and the MMP-3 in body are not sufficient to repair fibrosis completely.So,a large number of expression of MMP-3 can be used as the study target in the repair experimenta of radiation intestinal fibrosis.In this study,we obtain RNA of mouse cartilage,and cloned MMP-3 gene,constructed the expression vector LV-MMP-3-EGFP that labeled EGFP gene,packing lentiviral with GP2-293 T cells,and then modify ES cells and BM-MSCs.10GyX-ray irradiated fibroblasts were used to construct the fibrosis model.The transfected stem cells were co-cultured with fibrotic cells,and then observed green fluorescent protein in light microscope,the form change of cells,at the same time,the expression of MMP-3 and TGF-β protein was detected by Western Blot.MMP-3 gene was extrated and the lentiviral expression vector LV-MMP-3-EGFP was successfully constructed,and the green fluorescent protein was expressed in transfected GP2-293 T cells,ES cells and BM-MSCs,The expression of MMP-3 protein in the modified ES cells was higher than that in the control group.The expression of TGF-βprotein in 3T3 cells was not higher than that in the control group.The virus-infected BM-MSCs were co-cultured with 3T3 cells that irradiated,the density and the morphology of 3T3 cells changed in the experimental group.The results showed that LV-MMP-3-EGFP modified stem cells could express MMP-3 protein in large amount,which inhibite abnormal proliferation of 3T3 cells that irradiated,and cell changed to normal morphology,which constribute to repair,but the expression of TGF-β in 3T3 cells did not be affected significantly.This study provides a theoretical basis and a new direction for the clinical study of radioactive intestinal fibrosis.