Activation of Wnt signaling reduces high-glucose mediated damages on skin fibroblast cells

Objective(s): High-glucose (HG) stress, a mimic of diabetes mellitus (DM) in culture cells, alters expression of a large number of genes including Wnt and NF-κB signaling-related genes; however, the role of Wnt signaling during HG-mediated fibroblast damage and the relationship between Wnt and NF-κB signaling have not been understood. In this study, we aimed to investigate the ffects of Wnt signaling on HG-mediated damages. Materials and Methods: Wnt۳a was treated to HG-stressed human primary foreskin fibroblasts and the levels of Wnt signaling markers and cell proliferation were monitored. In addition, Wnt۳a and NF-κB signaling inhibitor were assisted to analyze the relationship between two pathways. Results: The results indicated that HG treatment repressed β-catenin level, and Wnt۳a treatment increased the levels of β-catenin and FZD۸ as well as cell proliferation. RNA-seq based transcriptome analysis identified ۲۰۷ up-regulated and ۲۰۰ down-regulated genes upon Wnt۳a supply. These altered genes are distributed into ۲۰ different pathways. In addition, gene ontology (GO) analysis indicates that ۲۰ GO terms are enriched. Wnt signaling genes were further verified by qRT-PCR and the results were similar with RNA-seq assay. Since NF-κB signaling negatively regulates Wnt marker gene expression, Bay۱۱۷۰۸۲, a typical NF-κB signaling inhibitor and Wnt۳a were supplemented for testing β-catenin and phosphorylated IκBα (p-IκBα), respectively. Conclusion: HG positively inhibits Wnt signaling, and signaling activation via supplementation of Wnt۳a rescued the defect caused by HG. NF-κB signaling negatively regulates accumulation of β-catenin, but Wnt signaling has no effects on IκBα activation.