title: Polysialyltransferase overexpression in Schwann cells mediates different effects during peripheral nerve regeneration.
abstract: The polysialic acid (PSA) moiety of the neural cell adhesion molecule (NCAM) has been shown to support dynamic changes underlying peripheral nerve regeneration. Using transgenic mice expressing polysialyltransferase ST8SiaIV under control of a glial-specific (proteolipid protein, PLP) promoter (PLP-ST8SiaIV-transgenic mice), we tested the hypothesis that permanent synthesis of PSA in Schwann cells impairs functional recovery of lesioned peripheral nerves. After sciatic nerve crush, histomorphometric analyses demonstrated impaired remyelination of regenerated axons at the lesion site and in target tissue of PLP-ST8SiaIV-transgenic mice, though the number and size of regenerating unmyelinated axons were not changed. This was accompanied by slower mechanosensory recovery in PLP-ST8SiaIV-transgenic mice. However, the proportion of successfully mono-(re)innervated motor endplates in the foot pad muscle was significantly increased in PLP-ST8SiaIV-transgenic mice when compared with wild-type littermates, suggesting that long-term increase in PSA levels in regenerating nerves may favor selective motor target reinnervation. The combined negative and positive effects of a continuous polysialyltransferase overexpression observed during peripheral nerve regeneration suggest that an optimized time- and differentiation-dependent control of polysialyltransferase expression in Schwann cells may further improve recovery after peripheral nerves injury.
authors.affiliation: Hannover Medical School, Institute of Neuroanatomy, 30625 Hannover, Germany.
authors.forename: Julia
authors.initials: J
authors.lastname: Jungnickel
authors.forename: Matthias
authors.initials: M
authors.lastname: Eckhardt
authors.forename: Kirsten
authors.initials: K
authors.lastname: Haastert-Talini
authors.forename: Peter
authors.initials: P
authors.lastname: Claus
authors.forename: Paul
authors.initials: P
authors.lastname: Bronzlik
authors.forename: Esther
authors.initials: E
authors.lastname: Lipokatic-Takacs
authors.forename: Helena
authors.initials: H
authors.lastname: Maier
authors.forename: Volkmar
authors.initials: V
authors.lastname: Gieselmann
authors.forename: Claudia
authors.initials: C
authors.lastname: Grothe
mesh_terms: D000818:Animals; D001369:Axons / Q000473:pathology; D002452:Cell Count; D015870:Gene Expression; D005786:Gene Expression Regulation; D051379:Mice; D008810:Mice, Inbred C57BL; D008822:Mice, Transgenic; D018482:Muscle, Skeletal / Q000294:innervation; D009416:Nerve Regeneration; D059348:Peripheral Nerve Injuries / Q000201:enzymology / Q000503:physiopathology; D011401:Promoter Regions, Genetic; D011994:Recombinant Proteins / Q000235:genetics / Q000378:metabolism; D012583:Schwann Cells / Q000201:enzymology* / Q000378:metabolism; D012584:Sciatic Nerve / Q000201:enzymology* / Q000473:pathology / Q000503:physiopathology; D012794:Sialic Acids / Q000378:metabolism; D012799:Sialyltransferases / Q000235:genetics / Q000378:metabolism*
chemical_list: D011994:Recombinant Proteins; D012794:Sialic Acids; C021319:polysialic acid; D012799:Sialyltransferases; C525848:ST8SiaIV protein, mouse