Effects of exogenous advanced glycation end products on oxidative stress and renal injury in healthy mice

This study evaluated the biological effects of exogenous advanced glycation end products (AGEs) on the induction of chronic kidney disease and the dose-effect relationship. Male C57BL/6 mice were placed on four diets, including saline and three other diets differing only in AGEs content (low-AGEs [LA], medium-AGEs [MA], and high-AGEs [HA] ratio, 1:3:5) for 4 weeks. With the increasing intake of AGEs, mice developed a significant increase in blood glucose and lipid levels, the fluorescence intensity of AGEs, Nε-(carboxymethyl)-lysine, Nε-(carboxyethyl)-lysine, and malondialdehyde levels, whereas their superoxide dismutase activity and glutathione levels were decreased significantly. HA had the highest urinary protein levels and the lowest creatinine clearance compared to the other groups. These suggested that AGEs are an essential contributor to increasing oxidative stress levels and intake of high-level AGEs induces more severe kidney function impairment. Meanwhile, the AGEs intake damaged the kidney structure in a dose-dependent manner, as evidenced by granular degeneration of kidney tubular epithelial cells and inflammatory cell infiltration. These findings shed light on the detrimental impacts of AGEs on human kidneys, which also will help reveal a dose-effect relationship of AGEs.