Regulation of neurite growth in immortalized mouse hypothalamic neurons and rat hippocampal primary cultures by teneurin C-terminal-associated peptide-1.
Teneurins are a highly conserved family of four type II transmembrane proteins that are expressed in the CNS. The protein possesses several functional domains including a unique bioactive 40-41 amino acid sequence at the extracellular terminus. Synthetic versions of this teneurin C-terminal-associated peptide (TCAP) can modulate cyclic AMP accumulation, cell proliferation and teneurin mRNA levels in vitro. Furthermore, i.c.v. injections of TCAP-1 into rat brain induce major changes in acoustic startle response behavior 3 weeks after administration, suggesting that the peptide may act to alter interneuron communication via changes in neurite and axon outgrowth. Synthetic mouse/rat TCAP-1 was used to treat cultured immortalized mouse hypothalamic cells, to determine if TCAP-1 could directly regulate neurite and axon growth. TCAP-1-treated cells showed a significant increase in the length of neurites accompanied by a marked increase in beta-tubulin transcription and translation as determined by real-time PCR and Western blot analysis, respectively. Changes in alpha-actinin-4 transcription and beta-actin protein expression were also noted. Immunofluorescence confocal microscopy using beta-tubulin antiserum showed enhanced resolution of beta-tubulin cytoskeletal elements throughout the cell. In order to determine if the effects of TCAP-1 could be reproduced in primary neuronal cultures, primary cultures of E18 rat hippocampal cells were treated with 100 nM TCAP-1. The TCAP-1-treated hippocampal cultures showed a significant increase in both the number of cells, dendritic branching and the presence of large and fasciculated beta-tubulin immunoreactive axons. These data suggest that TCAP acts, in part, as a functional region of the teneurins to regulate neurite and axonal growth of neurons.
Al Chawaf
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Department of Cell and Systems Biology, 25 Harbord Street, University of Toronto, Toronto, Ontario, Canada M5S 3G5.
St Amant
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Belsham
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Lovejoy
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D000818:Animals; D002454:Cell Differentiation / Q000187:drug effects / Q000502:physiology*; D002461:Cell Line, Transformed; D049109:Cell Proliferation / Q000187:drug effects; D002478:Cells, Cultured; D003598:Cytoskeletal Proteins / Q000187:drug effects / Q000378:metabolism; D020439:Growth Cones / Q000187:drug effects / Q000378:metabolism; D006624:Hippocampus / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D007031:Hypothalamus / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D051379:Mice; D008870:Microtubules / Q000187:drug effects / Q000378:metabolism; D009419:Nerve Tissue Proteins / Q000737:chemistry* / Q000378:metabolism* / Q000494:pharmacology*; D016501:Neurites / Q000187:drug effects / Q000378:metabolism*; D010446:Peptide Fragments / Q000378:metabolism / Q000494:pharmacology; D017434:Protein Structure, Tertiary / Q000502:physiology; D051381:Rats; D017207:Rats, Sprague-Dawley; D019063:Tenascin / Q000737:chemistry*; D014404:Tubulin / Q000187:drug effects / Q000378:metabolism
D003598:Cytoskeletal Proteins; D009419:Nerve Tissue Proteins; D010446:Peptide Fragments; C500186:TCAP-1 protein, mouse; D019063:Tenascin; D014404:Tubulin; C120530:teneurin-1