title: The synthetic NCAM mimetic peptide FGL mobilizes neural stem cells in vitro and in vivo.
abstract: The neural cell adhesion molecule (NCAM) plays a role in neurite outgrowth, synaptogenesis, and neuronal differentiation. The NCAM mimetic peptide FG Loop (FGL) promotes neuronal survival in vitro and enhances spatial learning and memory in rats. We here investigated the effects of FGL on neural stem cells (NSC) in vitro and in vivo. In vitro, cell proliferation of primary NSC was assessed after exposure to various concentrations of NCAM or FGL. The differentiation potential of NCAM- or FGL-treated cells was assessed immunocytochemically. To investigate its influence on endogenous NSC in vivo, FGL was injected subcutaneously into adult rats. The effects on NSC mobilization were studied both via non-invasive positron emission tomography (PET) imaging using the tracer [(18)F]-fluoro-L-thymidine ([(18)F]FLT), as well as with immunohistochemistry. Only FGL significantly enhanced NSC proliferation in vitro, with a maximal effect at 10 μg/ml. During differentiation, NCAM promoted neurogenesis, while FGL induced an oligodendroglial phenotype; astrocytic differentiation was neither affected by NCAM or FGL. Those differential effects of NCAM and FGL on differentiation were mediated through different receptors. After FGL-injection in vivo, proliferative activity of NSC in the subventricular zone (SVZ) was increased (compared to placebo-treated animals). Moreover, non-invasive imaging of cell proliferation using [(18)F]FLT-PET supported an FGL-induced mobilization of NSC from both the SVZ and the hippocampus. We conclude that FGL robustly induces NSC mobilization in vitro and in vivo, and supports oligodendroglial differentiation. This capacity renders FGL a promising agent to facilitate remyelinization, which may eventually make FGL a drug candidate for demyelinating neurological disorders.
authors.affiliation: Department of Neurology, University Hospital of Cologne, Kerpener Strasse 62, 50924, Cologne, Germany.
authors.forename: Rebecca
authors.initials: R
authors.lastname: Klein
authors.forename: Stefan
authors.initials: S
authors.lastname: Blaschke
authors.forename: Bernd
authors.initials: B
authors.lastname: Neumaier
authors.forename: Heike
authors.initials: H
authors.lastname: Endepols
authors.forename: Rudolf
authors.initials: R
authors.lastname: Graf
authors.forename: Meike
authors.initials: M
authors.lastname: Keuters
authors.forename: Joerg
authors.initials: J
authors.lastname: Hucklenbroich
authors.forename: Morten
authors.initials: M
authors.lastname: Albrechtsen
authors.forename: Stephen
authors.initials: S
authors.lastname: Rees
authors.forename: Gereon Rudolf
authors.initials: GR
authors.lastname: Fink
authors.forename: Michael
authors.initials: M
authors.lastname: Schroeter
authors.forename: Maria Adele
authors.initials: MA
authors.lastname: Rueger
mesh_terms: D000818:Animals; D015153:Blotting, Western; D002454:Cell Differentiation; D002470:Cell Survival; D002478:Cells, Cultured; D006624:Hippocampus / Q000166:cytology* / Q000378:metabolism; D007091:Image Processing, Computer-Assisted; D007124:Immunoenzyme Techniques; D066298:In Vitro Techniques; D018716:Molecular Mimicry; D019006:Neural Cell Adhesion Molecules / Q000235:genetics / Q000378:metabolism*; D058953:Neural Stem Cells / Q000166:cytology* / Q000378:metabolism; D055495:Neurogenesis / Q000502:physiology; D010455:Peptides / Q000235:genetics / Q000378:metabolism*; D049268:Positron-Emission Tomography; D012333:RNA, Messenger / Q000235:genetics; D051381:Rats; D060888:Real-Time Polymerase Chain Reaction; D020133:Reverse Transcriptase Polymerase Chain Reaction
chemical_list: C520137:FGLL peptide; D019006:Neural Cell Adhesion Molecules; D010455:Peptides; D012333:RNA, Messenger