In vivo tracing of transferred apoptotic cell labeled using CFSE: a flow cytometry-based assay method / 南方医科大学学报

<p><b>OBJECTIVE</b>To establish an assay method for detecting the migration of transferred apoptotic cells into the recipient using flow cytometry.</p><p><b>METHODS</b>Spleen lymphocytes were isolated and labeled with an intracellular amine dye, carboxyfluorescein diacetate succinimidyl ester (CFSE), to allow discrimination. The labeled cells were induced with dexamethasone to undergo apoptosis and transferred into recipient mice via tail venous transfusion. Flow cytometry and histological examination of different tissues were performed at different time points. The stability of CFSE labeling for apoptotic cells was also tested.</p><p><b>RESULTS</b>The CFSE-labeled apoptotic cells were highly fluorescent with a positive labeling rate of (98.0+/-1.9)%. The stability of CFSE-labeling was testified, and the CFSE-labeled apoptotic cells entering different tissues at different time points were detected by flow cytometry and verified by histological examination.</p><p><b>CONCLUSION</b>Flow cytometry using CFSE labeling is reliable, sensitive, precise and convenient for apoptotic cell tracing in vivo and in vitro.</p>

Hepatocyte growth factor and fibroblast growth factor-4-induced differentiation of human bone marrow mesenchymal stem cells into hepatocyte-like cells in vitro / 南方医科大学学报

<p><b>OBJECTIVE</b>To induce the differentiation of human bone marrow mesenchymal stem cells (HMSCs) into hepatocyte-like cells with hepatocyte growth factor (HGF) and fibroblast growth factor-4 (FGF-4) in vitro.</p><p><b>METHODS</b>HMSCs were induced to differentiate into hepatocyte-like cells by HGF (group B), FGF-4 (group C) and HGF+FGF-4 (group D) in vitro. Undifferentiated HMSCs and L-02 cells were used as the negative (group A) and positive (group E) controls, respectively. The changes of cell morphology were observed microscopically. The expressions of hepatic markers, alpha fetoprotein (AFP) and CK-18, were detected by immunocytochemical staining at different times after induction, and the differentiation ratios of the various groups of HMSCs were calculated on the basis of image analysis. The expressions of AFP and ALB were detected by immunofluorescence assay in each group at different times after induction, and the expressions of AFP and ALB mRNA by RT-PCR.</p><p><b>RESULTS</b>HMSCs gradually transformed into spindle-shaped, round, polygonal or irregular cells after induction. Immunocytochemical staining revealed positive AFP and CK18 expressions in groups B, C, and D after induction as well as in group E. The positive units (PU) of AFP and CK18 in group D calculated according to image analysis were significantly higher than that of groups A, B, and C. The expressions of AFP and ALB detected by immunofluorescence were both positive after induction in all groups except group A, similar to the findings of the expressions of AFP and ALB mRNA by RT-PCR.</p><p><b>CONCLUSION</b>HMSCs can be induced to differentiate into hepatocyte-like cells by HGF, FGF-4 and their combination at certain concentrations, and the hepatocyte-like cells can express some hepatic markers such as AFP, ALB, CK18, etc. HGF+FGF-4 may achieve more effective induction of HMSC differentiation into hepatocyte-like cells, and the efficiency of HGF is greater than that of FGF-4.</p>