Distinctive effects of different types of advanced glycation end-products (AGEs) on liver glucose metabolism

Increasing evidence has shown that AGEs can impair insulin sensitivity and affect glucose homeostasis. Owing to the heterogeneity of AGEs, it is still unclear which one has the strongest potential to disrupt glucose metabolism. Our study explored the effects of different types of AGEs on hepatic glucose metabolism. Three typical AGEs representing different formation pathways, namely AGEs from a glucose and lysine reaction mixture, methylglyoxal-modified BSA (MGO-BSA) and carboxymethyl lysine (CML), were chosen to treat HepG2 cells. The results indicate that only CML and MGO-BSA could disturb glucose metabolism, and MGO-BSA was the most active in promoting insulin resistance, as manifested by the inactivation of insulin receptor substrate-1 and decreased phosphorylation of AKT. Moreover, mice fed with an MGO-BSA-enriched diet showed increased blood glucose as well as impaired glucose tolerance. The present study revealed the distinctive effects of various AGEs on glucose metabolism and suggested that AGEs with high molecular weight might exert a higher pathogenic effect than small AGEs.