Abstract
Understanding the developmental steps shaping the formation of the neuromuscular junction (NMJ) connecting motoneurons to skeletal muscle fibers, is critical. Wnt morphogens are key players in the formation of this specialized peripheral synapse. Yet, the individual and collaborative functions of Wnts as well as their downstream pathways remain poorly understood at the NMJ. Here, we demonstrate through Wnt4 and Wnt11 gain of function studies in culture or in mice that Wnts enhance acetylcholine receptor (AChR) clustering and motor axon outgrowth. In contrast, loss of Wnt11 or Wnt-dependent signaling in vivo decreases AChR clustering and motor nerve terminal branching. Both Wnt4 and Wnt11 stimulate AChR clustering and mRNA downstream activation of the β-catenin pathway. Strikingly, Wnt4 and Wnt11 co-immunoprecipitate with Vangl2, a core component of the Planar Cell Polarity (PCP) pathway, which accumulates at embryonic NMJ. Moreover, mice bearing a Vangl2 loss of function mutation (looptail) exhibit a decreased number of AChR clusters and overgrowth of motor axons bypassing AChR clusters. Taken together, our results provide genetic and biochemical evidences that Wnt4 and Wnt11 cooperatively contribute to mammalian NMJ formation through activation of both the canonical and Vangl2-dependent core PCP pathways.
DOI
10.1242/dev.146167
Publication Date
2017-05-01
Publication Title
Development
Volume
144
Issue
9
Publisher
The Company of Biologists
ISSN
1477-9129
Embargo Period
2024-11-19
First Page
1712
Last Page
1724
Recommended Citation
Messéant, J., Ezan, J., Delers, P., Glebov, K., & et al. (2017) 'Wnt proteins contribute to neuromuscular junction formation through distinct signaling pathways', Development, 144(9), pp. 1712-1724. The Company of Biologists: Available at: https://doi.org/10.1242/dev.146167
