title: Labeling Schwann cells with CFSE-an in vitro and in vivo study.
abstract: Schwann cell (SC) transplantation is a promising strategy for axonal regeneration in the nervous system. Identifying the grafted SCs is an important aspect of this approach. The current study sought to establish a simple, reliable, fluorescent labeling method for SCs with a lipophilic molecule, 5-(and-6)-carboxyfluorescein diacetate succinimidyl ester (CFSE). Human SCs were incubated with varying concentrations of CFSE for different time periods. Based on the viability of labeled SCs and its plating efficiency, 1 min incubation with 5 microM CFSE at 37 degrees C was selected as the optimal labeling condition. Flow cytometric analysis and fluorescence microscopy demonstrated that the fluorescence of labeled SCs would fade over 4 weeks. Immunostaining for the phenotypic expression of SC markers, including S100, GFAP, P75, and MHC-I/II at 1 and 4 weeks after incubation with CFSE showed no difference between labeled and non-labeled SCs. Mixed cultures of labeled human SCs and rat SCs for 48 h were performed in triplicate and demonstrated that no leakage of dye from labeled SCs in cell culture occurred across species. A total of 14 injections of 2x10(5) labeled SCs were performed within the spinal cord at T8 and/or L1 level in 9 nude rats. The animals were euthanized at 1 (6 injections) and 4 weeks (8 injections). Grafted labeled SCs survived for at least 4 weeks, and could be easily recognized in the nude rat spinal cord without leakage of dye to surrounding cells. The SCs migrated in white and gray matter 3-6 mm away from the injection and in the central canal for up to 12 mm. These results suggest that CFSE can be used as a fluorescent tracer of human SCs for both in vitro and in vivo studies, for a period of at least 4 weeks.
authors.affiliation: The Miami Project to Cure Paralysis, Department of Neurosurgery, University of Miami School of Medicine, Miami, FL, USA.
authors.forename: Xiuming
authors.initials: X
authors.lastname: Li
authors.forename: Hector
authors.initials: H
authors.lastname: Dancausse
authors.forename: Israel
authors.initials: I
authors.lastname: Grijalva
authors.forename: Maria
authors.initials: M
authors.lastname: Oliveira
authors.forename: Allan D O
authors.initials: AD
authors.lastname: Levi
mesh_terms: D000818:Animals; D001562:Benzimidazoles / Q000493:pharmacokinetics; D002478:Cells, Cultured; D018920:Coculture Techniques; D004305:Dose-Response Relationship, Drug; D005260:Female; D005434:Flow Cytometry; D005452:Fluoresceins / Q000378:metabolism*; D005456:Fluorescent Dyes / Q000378:metabolism*; D006801:Humans; D007150:Immunohistochemistry; D010641:Phenotype; D051381:Rats; D011916:Rats, Inbred F344; D011923:Rats, Nude; D012583:Schwann Cells / Q000187:drug effects / Q000378:metabolism* / Q000637:transplantation; D013116:Spinal Cord / Q000187:drug effects / Q000378:metabolism / Q000637:transplantation; D013388:Succinimides / Q000378:metabolism*; D013997:Time Factors; D014180:Transplantation
chemical_list: C087165:5-(6)-carboxyfluorescein diacetate succinimidyl ester; D001562:Benzimidazoles; D005452:Fluoresceins; D005456:Fluorescent Dyes; D013388:Succinimides; C017807:bisbenzimide ethoxide trihydrochloride