Disintegration of Cav-1/β-catenin complex attenuates neuronal death after ischemia-reperfusion injury by promoting β-catenin nuclear translocation.

BACKGROUND

The roles of Caveolin-1 (Cav-1) and the Wnt/β-catenin signaling pathways in cerebral ischemia-reperfusion (I/R) injury are well established. The translocation of β-catenin into the nucleus is critical for regulating neuronal apoptosis, repair, and neurogenesis within the ischemic brain. It has been reported that the scaffold domain of Caveolin-1 (Cav-1) (residues 95-98) interacts with β-catenin (residues 330-337). However, the specific contribution of the Cav-1/β-catenin complex to I/R injury remains unknown.

METHODS AND RESULTS

To investigate the mechanism underlying the involvement of the Cav-1/β-catenin complex in the subcellular translocation of β-catenin and its subsequent effects on cerebral I/R injury, we treated ischemic brains with ASON (Cav-1 antisense oligodeoxynucleotides) or FTVT (a competitive peptide antagonist of the Cav-1 and β-catenin interaction). Our study demonstrated that the binding of Cav-1 to β-catenin following I/R injury prevented the nuclear accumulation of β-catenin. Treatment with ASON or FTVT after I/R injury significantly increased the levels of nuclear β-catenin. Furthermore, ASON reduced the phosphorylation of β-catenin at Ser33, Ser37, and Thr41, which contributes to its proteasomal degradation, while FTVT increased phosphorylation at Tyr333, which is associated with its nuclear translocation.

CONCLUSIONS

The above results indicate that the formation of the Cav-1/β-catenin complex anchors β-catenin in the cytoplasm following I/R injury. Additionally, both ASON and FTVT treatments attenuated neuronal death in ischemic brains. Our study suggests that targeting the interaction between Cav-1 and β-catenin serve as a novel therapeutic strategy to protect against neuronal damage during cerebral injury.