LAUSR

&NA; It is well known that Wnt5a activation plays a pivotal role in brain injury and &bgr;‐arrestin2 induces c‐Jun N‐terminal kinase (JNK3) activation is involved in neuronal cell death. Nonetheless, the relationship between Wnt5a and JNK3 remains unexplored during cerebral ischemia/reperfusion (I/R). In the present study, we tested the hypothesis that Wnt5a‐mediated JNK3 activation via the Wnt5a‐Dvl‐1‐&bgr;‐arrestin2‐JNK3 signaling pathway was correlated with I/R brain injury. We found that cerebral I/R could enhance the assembly of the Dvl‐1‐&bgr;‐arrestin2‐JNK3 signaling module, Dvl‐1 phosphorylation and JNK3 activation. Activated JNK3 could phosphorylate the transcription factor c‐Jun, prompt caspase‐3 activation and ultimately lead to neuronal cell death. To further explore specifically Wnt5a mediated JNK3 pathway activation in neuronal injury, we used Foxy‐5 (a peptide that mimics the effects of Wnt5a) and Box5 (a Wnt5a antagonist) both in vitro and in vivo. AS‐&bgr;‐arrestin2 (an antisense oligonucleotide against &bgr;‐arrestin2) and RRSLHL (a small peptide that competes with &bgr;‐arrestin2 for binding to JNK3) were applied to confirm the positive signal transduction effect of the Dvl‐1‐&bgr;‐arrestin2‐JNK3 signaling module during cerebral I/R. Furthermore, Box5 and the RRSLHL peptide were found to play protective roles in neuronal death both in vivo global and focal cerebral I/R rat models and in vitro oxygen glucose deprivation (OGD) neural cells. In summary, our results indicate that Wnt5a‐mediated JNK3 activation participates in I/R brain injury by targeting the Dvl‐1‐&bgr;‐arrestin2/JNK3 interaction. Our results also point to the possibility that disrupting Wnt5a‐JNK3 signaling pathway may provide a new approach for stroke therapy. HighlightsThe highlights of this article are listed as follows:Cerebral I/R induced the assembly of the Dvl‐1‐&bgr;‐arrestin2‐JNK3 signaling module.Wnt5a mediated JNK3 activation by adding the interaction of Dvl‐1‐&bgr;‐arrestin2‐JNK3.RRSLHL played protective roles by disrupting this module and the JNK3 activation.Box5 exerted neuroprotective roles via inhibiting Wnt5a‐JNK3 signaling pathway.