ABSTRACT
ObjectiveTo investigate the effect of transplantation of bone marrow mesenchymal stem cells （BMSCs） co-cultured with bone marrow-derived M2 macrophages （M2-BMDMs）， named as BMSCM2， on a rat model of liver cirrhosis induced by carbon tetrachloride （CCl4）/2-acetaminofluorene （2-AAF）. MethodsRat BMDMs were isolated and polarized into M2 phenotype， and rat BMSCs were isolated and co-cultured with M2-BMDMs at the third generation to obtain BMSCM2. The rats were given subcutaneous injection of CCl4 for 6 weeks to establish a model of liver cirrhosis， and then they were randomly divided into model group （M group）， BMSC group， and BMSCM2 group， with 6 rats in each group. A normal group （N group） with 6 rats was also established. Since week 7， the model rats were given 2-AAF by gavage in addition to the subcutaneous injection of CCl4. Samples were collected at the end of week 10 to observe liver function， liver histopathology， and hydroxyproline （Hyp） content in liver tissue， as well as changes in the markers for hepatic stellate cells， hepatic progenitor cells， cholangiocytes， and hepatocytes. A one-way analysis of variance was used for comparison of continuous data between multiple groups， and the least significant difference t-test was used for further comparison between two groups. ResultsCompared with the N group， the M group had significant increases in the activities of serum alanine aminotransferase （ALT） and aspartate aminotransferase （AST） （P<0.01）； compared with the M group， the BMSC and BMSCM2 groups had significant reductions in ALT and AST （P<0.01）， and the BMSCM2 group had significantly better activities than the BMSC group （P<0.05）. Compared with the N group， the M group had significant increases in Hyp content and the mRNA and protein expression levels of alpha-smooth muscle actin （α-SMA） in the liver （P<0.01）； compared with the M group， the BMSC and BMSCM2 groups had significant reductions in Hyp content and the expression of α-SMA （P<0.05）， and the BMSCM2 group had a significantly lower level of α-SMA than the BMSC group （P<0.01）. Compared with the N group， the M group had significant increases in the mRNA expression levels of the hepatic progenitor cell markers EpCam and Sox9 and the cholangiocyte markers CK7 and CK19 （P<0.01） and significant reductions in the expression levels of the hepatocyte markers HNF-4α and Alb （P<0.01）； compared with the M group， the BMSC and BMSCM2 groups had significant reductions in the mRNA expression levels of EpCam， Sox9， CK7， and CK19 （P<0.05） and significant increases in the mRNA expression levels of HNF-4α and Alb （P<0.05）， and compared with the BMSC group， the BMSCM2 group had significant reductions in the mRNA expression levels of EpCam and CK19 （P<0.05） and significant increase in the expression level of HNF-4α （P<0.05）. ConclusionM2-BMDMs can enhance the therapeutic effect of BMSCs on CCl4/2-AAF-induced liver cirrhosis in rats， which provides new ideas for further improving the therapeutic effect of BMSCs on liver cirrhosis.