Study On Repairing Liver Injury In Mice By Transplantation Of Simmental Bovine Intestinal Epithelial Stem Cells

In this experiment,Simmental bovine intestinal epithelial stem cells(IESCs)were used as experimental materials to study their isolation,culture and biological characteristics,explore their proliferation and multidirectional differentiation potential in vitro,provide theoretical basis for the protection and utilization of animal genetic resources,study their therapeutic effects on acute liver injury in mice,and provide reference for subsequent clinical application of stem cell therapy.The IESCs of simmental cattle were successfully isolated by collagenase I digestion,and were continuously subcultured in vitro,and the cells were successfully passed to 31 generations,and a total of 97 IESCs were frozen.The growth curve of IESCs experienced latency,exponential growth and plateau,and presented a typical S-type.The doubling time of cell population gradually increased with the increase of cell generations,and the cloning rate gradually decreased with the increase of cell generations.Both showed that the cell proliferation ability gradually decreased with the increase of generations.The number of IESCs chromosomes in Simmental cattle is 2n=60,a total of 30 pairs,including 29 pairs of autosomes,which are acrocentric chromosomes,and 1 pair of sex chromosomes,which are XX,which are metacentric chromosomes.There is no structural and numerical variation in chromosomes.The results of PT-PCR and immunofluorescence identification showed that the specific markers Lgr5,ITGB1,Bmi1,Hes1 and Musashi1 on the surface of IESCs cells were positive,which proved that the isolated cells were target cells.Simmental bovine IESCs were successfully induced to differentiate into adipocytes,osteoblasts and chondrocytes under different induction conditions.RT-PCR showed the adipose-specific gene PPAR-γAnd LPL,osteogenic specific genes SPP1 and RUNX2,cartilage specific genes ACAN and SOX9 were expressed positively,indicating that IESCs have the potential for multidirectional differentiation.The 7-week-old ICR mice were divided into control group,reagent injury group and cell treatment group,reagent injury group and cell treatment group mice were injected intraperitoneally with LPS to make models of acute liver injury,and the liver tissue sections were observed by H&E staining,and the liver tissue structure in the control group was normal;In the reagent injury group,the hepatocytes were irregularly arranged,and the cytoplasm of the cells was dissolved and necrotic,showing vacuolar shape;The liver injury of mice in the cell treatment group was significantly alleviated,and the vacuolation of liver cells was effectively repaired.The serum test of liver function indicators(ALT,AST and ALP)of mice in each group showed that the content of indicators was the highest at 2 hours,the damage was the most serious at this time,and then gradually decreased.At 7 days,the indicators of mice in the treatment group basically returned to normal.The frozen section of cell transplantation treatment showed that the tracer cells gathered in the damaged hepatocytes and tissues at the liver plate of the central vein of the liver lobμLe.The serological and histological tests showed that the liver injury was recovered,indicating that the IESCs of Simmental cattle had a certain repair effect on the liver injury.