High-fat diet caused renal damage in ApoE-/- mice via the activation of RAGE-mediated inflammation

High-fat diet (HFD) is the primary cause of metabolic syndrome associated chronic kidney disease. This study aimed to investigate the pathogenesis of HFD-induced kidney injury. ApoE(-/-) mice were fed with HFD and kidney damage was examined. In addition, HK-2 human renal proximal tubular epithelial cells were treated with fructose and receptor of advanced glycation end products (RAGE) siRNA. The results showed that HFD increased body weight, blood glucose and insulin resistance in ApoE(-/-) mice. The kidney damage was associated with increased oxidative stress and strong staining of RAGE and NF-kappa B in kidney tissues, as well as high serum levels of TNF-alpha, IL-1 beta and IL-6. Western-blot analysis showed that HFD increased the levels of RAGE, p-I kappa B alpha, p-NF-kappa B, bax, caspase-3 and caspase-9 but decreased the levels of Bcl-2 in kidney tissues. In HK-2 cells, fructose promoted the secretion of TNF-alpha, IL-1 beta and IL-6 and increased the levels of RAGE, p-I kappa B alpha, p-NF-kappa B, bax, caspase-3 and caspase-9, but decreased the levels of Bcl-2. Moreover, RAGE siRNA could attenuate increased levels of p-I kappa B alpha, p-NF-kappa B, bax, caspase-3 and caspase-9 while restore decreased levels of Bcl-2 in fructose-treated HK-2 cells. In conclusion, HFD causes kidney injury by promoting oxidative stress, inflammation and apoptosis possibly through the activation of RAGE/NF-kappa B pathway.