Schwann cell-derived neuregulin-2alpha can function as a cell-attached activator of muscle acetylcholine receptor expression

Glia. 2006 Nov 1;54(6):630-7. doi: 10.1002/glia.20413.

Abstract

Here we show that neuregulin-2 (Nrg-2) alpha- and beta-isoforms can activate acetylcholine receptor (AChR) transcription as surface-attached ligands. More importantly, we demonstrate that Schwann cells that express Nrg-2alpha on their cell surface, the same Nrg-2 isoform expressed by terminal Schwann cells at the neuromuscular junction, can induce AChR expression if brought into cell-to-cell contact with myotubes specifically expressing ErbB4. These Schwann cells, the D6P2T cell line, induce AChR expression apparently as well as 293T cells transfected with Nrg-2beta, the isoform with the highest AChR-inducing activity when presented in a soluble form. These results provide a potential role for the previously reported, paradoxical perisynaptic accumulation of Nrg-2alpha, the isoform with the least AChR-inducing activity when presented in a soluble form. They also raise the possibility that Schwann cell-derived Nrg-2 could activate ErbB receptors on the synaptic sarcolemma and that this could account, at least in part, for the Nrg-mediated regulation of AChR expression.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Animals
  • Animals, Newborn
  • Cell Communication / physiology
  • Cell Differentiation / physiology
  • Cell Line
  • Cells, Cultured
  • ErbB Receptors / metabolism
  • Membrane Proteins / metabolism
  • Muscle Fibers, Skeletal / metabolism
  • Muscle, Skeletal / innervation*
  • Muscle, Skeletal / metabolism
  • Nerve Growth Factors / metabolism*
  • Neuromuscular Junction / drug effects
  • Neuromuscular Junction / metabolism*
  • Protein Isoforms / metabolism
  • Rats
  • Receptor, ErbB-4
  • Receptors, Nicotinic / drug effects
  • Receptors, Nicotinic / metabolism*
  • Schwann Cells / drug effects
  • Schwann Cells / metabolism*
  • Synaptic Membranes / metabolism
  • Synaptic Transmission / physiology*

Substances

  • Membrane Proteins
  • Nerve Growth Factors
  • Nrg2 protein, rat
  • Protein Isoforms
  • Receptors, Nicotinic
  • ErbB Receptors
  • Erbb4 protein, rat
  • Receptor, ErbB-4