Expression Of Elastin During Repair Of Rat Uterine Ligament Injury By Human Endometrial Mesenchymal Stem Cells

Objective:In this study,the rat model of uterine ligament mechanical injury was established,and the multi-directional differentiation potential of endometrial mesenchymal stem cells was used to regenerate and repair the injured ligament tissue,and the expression of elastin in the ligaments before and after repair was detected.To explore the partial regeneration or complete regeneration function of stem cells during ligament tissue damage repair.Methods:The first normal rat uterine ligament mechanical injury model was established by selecting clean SD female rats weighing 300±10g,respectively,3 days,6 days,9 days,12 days,15 days after surgery and normal rats.Uterine ligaments,each group was taken after formalin soaking,after paraffin-embedded tissue,hematoxylin staining method was used to analyze the healing of scar at different time points to determine the best time for scar repair.The second model of mechanical injury of rat uterine ligament with stem cells was established.This time,unlabeled human endometrial mesenchymal stem cells were locally injected into the injured ligament site,respectively,3 days,6 days,9 days after surgery.After 12 days of sampling,the mouse anti-human nuclear antibody(mAb1281)was used for nuclear labeling,and the positive cells were transplanted cells.The immunofluorescence technique was used to observe the survival of transplantedhuman endometrial mesenchymal stem cells in rats.Through the two modeling,the best time point for scar repair is finally selected.Based on this time point,the model of scar group,stem cell group and normal control group was established.The expression of elastin during scar repair was compared by hematoxylin staining,immunohistochemistry and westen-blot.To explore the partial regeneration or complete regeneration function of stem cells during ligament tissue damage repair.Results:1.Selection of the best time point for scar repair by hematoxylin staining: HE staining of normal rat uterine ligaments at 3 days,6 days,9 days,12 days,15 days after operation,and found that ligament tissue was found 3 days after operation.It is obvious that a large number of thin capillaries,inflammatory cells,fibroblasts,and collagen fibers are scarce.The angiogenesis,inflammatory cells and fibroblasts in the injured tissue gradually decrease with time,and the reticular fibers and collagen fibers gradually increase,12 days.There was no significant difference from the 15 day tissue scar repair,and 12 days was taken as the experimental time node.2.Immunofluorescence staining was used to detect the survival of human endometrial mesenchymal stem cells: after injection of human endometrial mesenchymal stem cells with mouse anti-human nuclear antibody(mAb1281),3 days,6 days,and 9days after observation.The survival of stem cells in the uterine ligament of rats in days and 12 days showed that the immunofluorescence reaction was still positive for 12 days,indicating that mesenchymal stem cells still survived at this time point.3.Comparison of scar group,stem cell and normal control group 12 days after surgery:(1)The results of immunohistochemistry showed that the OD values of scar group,stem cell group and normal group were 0.09 ± 0.01,0.23 ± 0.04 and 0.22 ± 0.02,respectively.The positive expression of elastin in scar group was lower than that in stemcell group.The significance of the study(P<0.05),the positive expression of elastin antibody in the stem cell group compared with the normal control group was not statistically significant(P>0.05).(2)The results of immunoblotting showed that the ratio of the gray value of elastin in the scar group,the stem cell group and the normal control group to the ?-Actin gray value was 0.17±0.01,0.34±0.12,0.32±0.10,elastin.The expression in the scar group was lower than that in the stem cell group(P<0.05).There was no significant difference in the expression of elastin antibody between the stem cell group and the normal control group(P>0.05).Conclusion:The expression of elastin in the stem cell group was significantly higher than that in the uninjected stem cell,indicating that stem cells showed their differentiation potential during the repair of damaged ligament tissue,which can differentiate into fibroblasts,which is partially or completely regenerated.