Advanced Glycation End Products and Their Receptors as Risk Factors for Aging

Glycation is the reaction between amino residues of proteins and carbonyl of reducing sugars. French Louis Camille Maillard discovers this reaction from the browning reaction by amino acid and sugar, and it is widely known for the food chemistry as the Maillard reaction. The hemoglobin A1c (HbA1c) measured all over the world as a marker of glycemic control is equivalent to the Amadori rearrangement products, which is the early stage product of the Maillard reaction. Therefore, glycation progresses even in the healthy subject since carbohydrates are used as an energy source. Then, the Amadori products are changed to Advanced Glycation End-products (AGEs), which shows the autofluorescence, browning, and cross-linking by oxidation, dehydration, and a condensation reaction. Furthermore, AGE-proteins are recognized by AGE receptor such as RAGE (receptor for AGE). This review describes the proposed Pathways for the formation of AGEs during the Maillard reaction and role of the AGEs in the pathogenesis of age-related diseases.