Presence of glyceraldehyde-derived advanced glycation end-products in the liver of insulin-resistant mice.
Insulin resistance is a fundamental feature of metabolic disorders such as metabolic syndrome. The formation of advanced glycation end-products (AGEs) is increased in patients with hyperglycemia, which results in the loss of protein function. Therefore, considerable attention has been paid to the pathological significance of AGEs in diseases associated with insulin resistance. We previously demonstrated that all-trans-retinoic acid (ATRA) ameliorated insulin resistance in mice that were fed a high-fat, high-fructose (HFHFr) diet. However, it is unclear whether the HFHFr diet increases the production of AGEs in the liver, and whether ATRA affects this production. In the present study, we investigated the production of glyceraldehyde-derived AGEs (Glycer-AGEs) in the liver of HFHFr diet-induced insulin-resistant mice using an antibody against Glycer-AGEs. We noted a remarkable formation of Glycer-AGEs with estimated molecular weights of approximately 265, 282, and 312 kDa in the liver of the insulin-resistant mice; however, the production of Glycer-AGEs was limited in the control. In accordance with previous observations, these Glycer-AGEs in mice disappeared after treatment with ATRA. These results suggest that hepatic Glycer-AGEs can be useful markers for the diagnosis and therapeutic evaluation of insulin resistance and may play a pathological role in the development of insulin resistance.