| First Author | Horigane S | Year | 2016 |
| Journal | Mol Brain | Volume | 9 |
| Pages | 8 | PubMed ID | 26772170 |
| Mgi Jnum | J:318781 | Mgi Id | MGI:6859237 |
| Doi | 10.1186/s13041-016-0189-3 | Citation | Horigane S, et al. (2016) Facilitation of axon outgrowth via a Wnt5a-CaMKK-CaMKIalpha pathway during neuronal polarization. Mol Brain 9:8 |
| abstractText | BACKGROUND: Wnt5a, originally identified as a guidance cue for commissural axons, activates a non-canonical pathway critical for cortical axonal morphogenesis. The molecular signaling cascade underlying this event remains obscure. RESULTS: Through Ca(2+) imaging in acute embryonic cortical slices, we tested if radially migrating cortical excitatory neurons that already bore primitive axons were sensitive to Wnt5a. While Wnt5a only evoked brief Ca(2+) transients in immature neurons present in the intermediate zone (IZ), Wnt5a-induced Ca(2+) oscillations were sustained in neurons that migrated out to the cortical plate (CP). We wondered whether this early Wnt5a-Ca(2+) signaling during neuronal polarization has a morphogenetic consequence. During transition from round to polarized shape, Wnt5a administration to immature cultured cortical neurons specifically promoted axonal, but not dendritic, outgrowth. Pharmacological and genetic inhibition of the CaMKK-CaMKIalpha pathway abolished Wnt5a-induced axonal elongation, and rescue of CaMKIalpha in CaMKIalpha-knockdown neurons restored Wnt5a-mediated axon outgrowth. CONCLUSIONS: This study suggests that Wnt5a activates Ca(2+) signaling during a neuronal morphogenetic time window when axon outgrowth is critically facilitated. Furthermore, the CaMKK-CaMKIalpha cascade is required for the axonal growth effect of Wnt5a during neuronal polarization. |
