title: In vivo tracking of implanted stem cells using radio-labeled transferrin scintigraphy.
abstract: The possibility of monitoring stem cells in vivo with radionuclide imaging after transplantation was investigated. Based on the results of a radioligand receptors assay that human mesenchymal stem cells (hMSCs) express a high level of transferrin receptors, iodinated transferrin (131I-Tf(Fe)2) was chosen as the radiotracer for imaging the cells implanted into the spinal cords of rabbits. Accumulation of radioactivity at the cell transplanted sites was assessed 16 and 24 hours post-intrathecal injection of 131I-Tf(Fe)2. Transferrin receptors expression and Tf binding of the implanted cells were verified by immunofluorescence and ex vivo phosphor imaging. The specificity of Tf uptake of hMSCs was proved through control experiments, i.e., replacing 131I-Tf(Fe)2 with 131I labeled human serum albumin as the tracer or substituting hMSCs with phosphate buffered saline as the grafts. Despite some defects, such as the invasive administration of the tracer and the non-specificity of transferrin receptors as a marker of stem cells in this preliminary study, the technique of nuclear medicine imaging is considered to have great potential in tracking implanted cells in vivo.
authors.affiliation: Department of Nuclear Medicine, The Chinese PLA General Hospital, Beijing, China.
authors.forename: Weimin
authors.initials: W
authors.lastname: Ding
authors.forename: Jinzhu
authors.initials: J
authors.lastname: Bai
authors.forename: Jinming
authors.initials: J
authors.lastname: Zhang
authors.forename: Yingmao
authors.initials: Y
authors.lastname: Chen
authors.forename: Limin
authors.initials: L
authors.lastname: Cao
authors.forename: Yijie
authors.initials: Y
authors.lastname: He
authors.forename: Li
authors.initials: L
authors.lastname: Shen
authors.forename: Fan
authors.initials: F
authors.lastname: Wang
authors.forename: Jiahe
authors.initials: J
authors.lastname: Tian
mesh_terms: D000818:Animals; D005260:Female; D005455:Fluorescent Antibody Technique; D006863:Hydrogen-Ion Concentration; D007457:Iodine Radioisotopes; D007700:Kinetics; D011817:Rabbits; D011869:Radioligand Assay; D019275:Radiopharmaceuticals / Q000134:cerebrospinal fluid; D011990:Receptors, Transferrin / Q000187:drug effects / Q000378:metabolism; D033581:Stem Cell Transplantation; D014168:Transferrin / Q000134:cerebrospinal fluid
chemical_list: D007457:Iodine Radioisotopes; D019275:Radiopharmaceuticals; D011990:Receptors, Transferrin; D014168:Transferrin