Abstract
WNT-β-catenin signaling has long been implicated in specifying the pattern formation during development and, more recently, in regeneration of injured central nervous system. The differential expressions of a subset of WNT genes during regeneration of injured spinal cord, retina, and brain neurons suggest a tissue-specific expression pattern of WNT ligands. These findings also reveal a mechanistic difference in the transcription of WNTs. As the transcriptional regulation of WNT genes during neuronal regeneration was largely unknown, a recent report by Chang et al. documented an enhancer of WNT3A gene of which a histone H3K4me1-primed epigenetic code directs the chromatin transformation and thus the transcription of WNT3A. It remains to be explored whether a novel super enhancer may be responsible for the transcription of a cluster of WNT genes. It seems likely that a concerted increase of a set of WNT genes would be an effective regeneration program for injured brain neurons, possibly through promoting expression of differentiation genes within neuronal progenitors.