title: Cell motility of neural stem cells is reduced after SPIO-labeling, which is mitigated after exocytosis.
abstract: MRI is used for tracking of superparamagnetic iron oxide (SPIO)-labeled neural stem cells. Studies have shown that long-term MR tracking of rapidly dividing cells underestimates their migration distance. Time-lapse microscopy of random cellular motility and cell division was performed to evaluate the effects of SPIO-labeling on neural stem cell migration. Labeled cells divided symmetrically and exhibited no changes in cell viability, proliferation, or apoptosis. However, SPIO-labeling resulted in decreased motility of neural stem cells as compared with unlabeled controls. When SPIO-labeled neural stem cells and human induced pluripotent stem cells were transplanted into mouse brain, rapid exocytosis of SPIO by live cells was observed as early as 48 h postengraftment, with SPIO-depleted cells showing the farthest migration distance. As label dilution is negligible at this early time point, we conclude that MRI underestimation of cell migration can also occur as a result of reduced cell motility, which appears to be mitigated following SPIO exocytosis.
authors.affiliation: Russell H. Morgan Department of Radiology and Radiological Science, Division of MR Research, The Johns Hopkins University School of Medicine, Baltimore, Maryland 21205, USA.
authors.forename: Stacey M
authors.initials: SM
authors.lastname: Cromer Berman
authors.lastname: Kshitiz
authors.forename: C Joanne
authors.initials: CJ
authors.lastname: Wang
authors.forename: Inema
authors.initials: I
authors.lastname: Orukari
authors.forename: Andre
authors.initials: A
authors.lastname: Levchenko
authors.forename: Jeff W M
authors.initials: JW
authors.lastname: Bulte
authors.forename: Piotr
authors.initials: P
authors.lastname: Walczak
mesh_terms: D000818:Animals; D002455:Cell Division / Q000187:drug effects; D002465:Cell Movement / Q000187:drug effects*; D002478:Cells, Cultured; D002531:Cerebellum / Q000166:cytology*; D003287:Contrast Media; D003911:Dextrans / Q000493:pharmacokinetics*; D005089:Exocytosis / Q000502:physiology*; D058185:Magnetite Nanoparticles; D051379:Mice; D008815:Mice, Inbred Strains; D058953:Neural Stem Cells / Q000378:metabolism / Q000502:physiology*; D039904:Pluripotent Stem Cells / Q000378:metabolism* / Q000502:physiology*; D033581:Stem Cell Transplantation
chemical_list: D003287:Contrast Media; D003911:Dextrans; D058185:Magnetite Nanoparticles; C097921:ferumoxtran-10