Figure 7.

Schematic diagram of the protective mechanism of LE in ischemic reperfusion injury. LE increases the lipid modification of Wnt proteins by PORCN. Lipid-modified/active Wnt proteins are released to the extra-cellular space for the binding to Frizzled/LRP receptors. The activated receptors induce the phosphorylation of GSK-3β, which prevents the destruction complex from the degradation of β-catenin by proteasomes. Preserved levels of β-catenin lead to cell survival. The injection of XAV939 prevents the phosphorylation of GSK-3β, which allows β-catenin degradation for cell death. Abbreviations: PORCN—porcupine, Wnt—wingless integration, LRP—low-density lipoprotein receptor-related protein, GSK-3β—glycogen synthase kinase 3β, APC—adenomatous polyposis coli, AXIN—axis inhibition protein.