Stimulation of choline acetyltransferase by C3d, a neural cell adhesion molecule ligand

Authors

  • Alison Burgess,

    1. Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, Ontario, Canada
    2. Sunnybrook Health Sciences Centre, Clinical Integrative Biology, Neuroscience Research, Sunnybrook Health Sciences Centre, Toronto, Ontario, Canada
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  • Saumya Saini,

    1. Sunnybrook Health Sciences Centre, Clinical Integrative Biology, Neuroscience Research, Sunnybrook Health Sciences Centre, Toronto, Ontario, Canada
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  • Ying-Qi Weng,

    1. Sunnybrook Health Sciences Centre, Clinical Integrative Biology, Neuroscience Research, Sunnybrook Health Sciences Centre, Toronto, Ontario, Canada
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  • Isabelle Aubert

    Corresponding author
    1. Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, Ontario, Canada
    2. Sunnybrook Health Sciences Centre, Clinical Integrative Biology, Neuroscience Research, Sunnybrook Health Sciences Centre, Toronto, Ontario, Canada
    • Sunnybrook Health Sciences Centre, Room S113, 2075 Bayview Ave., Toronto, Ontario, Canada M4N 3M5
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Abstract

Septal cholinergic neurons project to the hippocampus and release acetylcholine, a neurotransmitter involved in learning and memory. The enzyme choline acetyltransferase (ChAT) is responsible for synthesizing acetylcholine. Promoting ChAT activity and acetylcholine release can lead to new treatments for neurodegenerative diseases with cholinergic deficits, such as Alzheimer's disease. We present evidence that the synthetic molecule C3d, which is a peptide mimetic of the neural cell adhesion molecule (NCAM), promotes ChAT activity in cultures of rat embryonic septal neurons. Our data demonstrate that ChAT activity triggered by C3d is dependent on the fibroblast growth factor receptor (FGFR) and the mitogen-activated protein kinase (MAPK) pathway. C3d did not affect the number of cholinergic neurons in culture, indicating that NCAM homophilic binding enhances ChAT activity, without affecting cholinergic cell survival. In conclusion, the NCAM mimetic peptide C3d promotes ChAT activity in septal neurons through FGFR and MAPK. These findings are relevant to the design of new strategies aimed at stimulating cholinergic function and improving cognition in disorders such as Alzheimer's disease. © 2008 Wiley-Liss, Inc.

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