Insulin Accelerates the Endocytic Uptake and Degradation of Advanced Glycation End-Products Mediated by The Macrophage Scavenger Receptor

Summary The macrophage scavenger receptor (MSR), one of the receptors for advanced glycation end-products (AGEs), mediates endocytic uptake and degradation of AGE-proteins in several cell types. In the present study, we examined whether MSR function was regulated by insulin signaling. Co-expression of human insulin receptor (IR) with MSR in Chinese hamster ovary (CHO) cells showed that insulin accelerated the degradation of AGE proteins to 160% of the control. The insulin-enhanced endocytic uptake of AGE-proteins was significantly inhibited by phosphatidylinositol-3-OH kinase (PI(3)K) inhibitors, wortmannin and LY294002. Thus, insulin signaling through the PI(3)K pathway may regulate MSR-mediated endocytic uptake of AGE-proteins.