Fig. 1.

Different roles of the Wnt signaling pathways in PD and DR. In DR, the levels of LRP6, Frizzled, and β-catenin are upregulated, and Wnt signaling downstream target genes are overexpressed, which result in the increased neoangiogenesis, inflammation, and oxidative stress, thus contributing to the development of DR. In PD, the levels of LRP5/6 and β-catenin are downregulated, and Wnt signaling downstream inhibits the expression of target genes, which lead to increased inflammation and oxidative stress, thereby promoting the development of PD