IRES-mediated Wnt2 translation in apoptotic neurons triggers astrocyte dedifferentiation.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 36056026.
- Also identified by DOI 10.1038/s41536-022-00248-1 and PMC identifier 9440034.
- Licence recorded as CC BY.
- The licence permits redistribution, so the abstract is shown in full and the full text is available from the publisher.
Abstract
Reactive astrogliosis usually bears some properties of neural progenitors. How injury triggers astrocyte dedifferentiation remains largely unclear. Here, we report that ischemia induces rapid up-regulation of Wnt2 protein in apoptotic neurons and activation of canonical Wnt signaling in reactive astrocytes in mice, primates and human. Local delivery of Wnt2 shRNA abolished the dedifferentiation of astrocytes while over-expressing Wnt2 promoted progenitor marker expression and neurogenesis. Both the activation of Wnt signaling and dedifferentiation of astrocytes was compromised in ischemic caspase-3<sup>-/-</sup> cortex. Over-expressing stabilized β-catenin not only facilitated neurogenesis but also promoted functional recovery in ischemic caspase-3<sup>-/-</sup> mice. Further analysis showed that apoptotic neurons up-regulated Wnt2 protein via internal ribosome entry site (IRES)-mediated translation. Knocking down death associated protein 5 (DAP5), a key protein in IRES-mediated protein translation, significantly diminished Wnt activation and astrocyte dedifferentiation. Our data demonstrated an apoptosis-initiated Wnt-activating mechanism which triggers astrocytic dedifferentiation and facilitates neuronal regeneration.