Efficacy And Mechanism Of Collagen Gel Combined With Bone Marrow Mesenchymal Stem Cells In The Treatment Of Acute Liver Failure

Research background:Acute liver failure(ALF)is a sudden and severe liver injury caused by a variety of causes.Liver transplantation is the most effective treatment for ALF,but its application is limited by the shortage of donors and the high cost of surgery.Mesenchymal stem cells(MSCs)transplantation,as a new type of cell transplantation therapy,has become a research hotspot in the treatment of ALF.Collagen gel has friendly biocompatibility and unique topological 3d structure,which can not only provide a carrier for targeted delivery of cells,but also provide a3 d environment for cell growth,so as to maintain and improve the function and survival of MSCs.However,at present,there is a lack of research on whether the transplanted collagen gel combined with MSCs has a better therapeutic effect on ALF.In this study,a mouse ALF model induced by d-galactosamine(D-Gal)was established to detect the efficacy of collagen gel combined MSCs transplantation in the treatment of ALF in mice,providing an experimental basis and basis for the clinical treatment of ALF by collagen gel combined MSCs transplantation.Research objectives:The purpose of this study was to investigate the therapeutic effect of collagen gel transplantation combined with MSCs on acute liver failure.Research Methods:The MSCs of C57BL/6 mice were isolated,adhered to the wall in vitro,culturemedium was changed every 3 days,and the experiment was carried out with MSCs transferred to 3-6 generations.MSCs were mixed with collagen gel for preparation and observed by scanning electron microscope.Fluorescent-pretreated MSCs and collagen-gel composite MSCs were injected into the liver of ALF mice at multiple points for imaging detection of small animals in vivo and image collection.C57BL/6 mice were randomly divided into 5 groups :(1)control group(normal saline);(2)D-Gal + PBS group;(3)D-Gal +collagen gel group;(4)D-Gal + MSCs group;(5)D-Gal + collagen gel-MSCs group.Mice in the first group were intraperitoneally injected with normal saline,and mice in the other four groups were intraperitoneally injected with d-gal to establish a mouse model of acute liver failure.After 12 hours of D-Gal injection,ALF mice in the four groups were injected with200?l PBS,200?l collagen gel,1x106 MSCs and collagen gel-mscs in liver,respectively,and the survival rates of mice in each group were calculated.Alanine transaminase(ALT),aspartate aminotransferase(AST)and inflammatory cytokines were detected in mice of each group,and the proliferation and apoptosis of liver cells in the liver tissues of mice of each group were detected by Western blot and histopathological staining.Results:Scanning electron microscopy showed that collagen gel had a good compatibility with MSCs,and in vivo imaging detection of small animals showed that almost all the signals were concentrated in the liver and no signal was found in the spleen.The signal of combined MSCs transplantation with collagen gel was stronger than that of ALF mice transplanted with MSCs alone.Serum AST and ALT levels were significantly increased after treatment with D-Gal,and reached the peak on the third day after D-Gal administration.Liver function indexes in D-Gal +collagen gel-MSCs group and D-Gal + MSCs group were significantly better than those in D-Gal + PBS group and D-Gal+ collagen gel group(P<0.05),and D-Gal +collagen gel-MSCs group was significantly improved compared with D-Gal + MSCs group(P<0.05).HE staining indicated that the pathological changes in the D-Gal +collagen gel-MSCs group and the D-Gal + MSCs group were less severe than those in the D-Gal + PBS group and D-Gal+collage gel group,and the D-Gal + collagen gel-MSCs group were less severe than those in the D-Gal + MSCs group.The 3-day survival rate of the D-Gal+ PBS group and the D-Gal+collagen gel group ALF group was less than 15%,and there was no significant difference between the two groups.The 7-day survival rate of mice in MSCs treatment group was 44%,while the survival rate of mice in collagen-gel composite MSCs treatment group was significantly higher than that in MSCs treatment alone(the 7-day survival rate was76%).Both Western Bloting and immunohistochemistry showed that the proliferation rate of hepatocytes in the D-Gal + collagen gel-MSCs group was significantly higher than that in the D-Gal + MSCs group,the D-Gal + PBS group and D-Gal+collage gel group,and the cell apoptosis was significantly reduced.Further studies have found that D-Gal + collagen gel-MSCs plays a therapeutic role by activating the PI3K/AKT signaling pathway.Therefore,experiments have shown that although collagen gel itself has no therapeutic effect on ALF,collagen gel combined with MSCs transplantation can enhance the liver colonization ability of MSCs and produce better therapeutic effect on ALF in mice.The smooth progress of this study provides a new idea for the treatment of ALF by MSCs transplantation.Conclusion:(1)Collagen gel combined with MSCs transplantation can enhance the liver colonization ability of MSCs and effectively reduce ALF in mice;(2)Collagen gel combined with MSCs can alleviate liver injury by inhibiting apoptosis and promoting cell proliferation;(3)Transplanted collagen gel combined with MSCs activates PI3K/AKT signaling pathway to improve liver cell function.