Comparison Study On Several Methods For Human Dermal Stem Cell Labeling And Tracking

Background：Stem cells have the characteristics of self-renewal and differentiation. The use ofstem cell transplantation has become a hot spot for the treatment of many diseases. Invitro labeling and in vivo tracking of stem cells can provide important information forelucidating the biological behaviors of stem cells，such as colonization, distribution,migration and differentiation, which have important significance in stem cell researchand application. By using the fluorescent dye PKH26, nucleic acid markers BrdU andspecific antibodies to human cells, this study compared the advantages anddisadvantages of the above three methods and then evaluate their potential applicationvalue for stem cell labeling and tracking.Methods：In the first part of this study, human dermal stem cells were labeled in vitro with thefluorescent dye PKH26, nucleic acid marker BrdU and three human specific antibodiesrespectively to establish stable methods for stem cell labeling in vitroIn the second part, the C57BL/6J mice which received different doses of wholebody radiation were used as recipients and2×106labeled human dermal stem cells weretransplanted through the tail vein. The distribution of transplanted cells was detectedwith optical microscopy and fluorescence microscopy at each time points.Results：1. BrdU showed good labeling efficacy for human dermal stem cells in culture andthe engrafted cells were successfully detected in the lung of recipient mice usingimmunohistiochemical staining with anti-BrdU antibody.2. Fluorescent dye PKH26could label human demal stem cells in vitro, but thelabeled cells were not detected in the recipient mice after transplantation.3. Anti-human β-2-Microglobulin antibody (Santa Cruz, sc-80668) and anti-human endoglin antibody (Dako, M3527) failed to identify human cells both in vitro and in vivo.Although anti-human nuclei antibody (Millipore, MAB1281) could identify human cellsin vitro, we could not detect any human dermal stem cells in recipient mice.Conclusions：1. BrdU can be used as in vitro labeling and in vivo tracking reagent in stem celltransplantation research owing to its high labeling efficiency and stable trackingproperties.2. Although fluorescent dye PKH26has shown good labeling efficiency in vitro, butmore investigation needs to be done when it is used to tracking human stem cells in vivo.3. The quality and stability of human specific antibodies varied significantly whenthey were used for in vivo tracking research of human stem cells. The antibodies used inthis study, including anti-human nuclei antibody, anti-human β-2-Microglobulinantibody and anti-human endoglin antibody, failed to detected human stem cells for invivo tracking.