Chronic Inflammation Potentiates Kidney Aging

Chronic inflammation, characterized by increased serum levels of tumor necrosis factor-α, interleukin-6, C-reactive protein, and plasminogen activator inhibitor-1, and the presence of inflammatory-related diseases, are seen commonly in aging. Both the dysregulation of immune cells and phenotypic changes in parenchymal cells may contribute to chronic inflammation in aging. Moreover, senescent cells are an important source of inflammatory factors. Oxidative stress, via activation of p38 and c-Jun N-terminal kinase and induction of cell senescence, is likely to play a critical role in inflammation. Endoplasmic reticulum stress also may be present in aging and be involved in inflammation. Advanced glycation end products also are important contributors to inflammation in aging. Because the kidney is a major site for the excretion, and perhaps the degradation, of advanced glycation end products and small inflammatory molecules, reduced renal function in aging may promote oxidative stress and inflammation. Chronic inflammation in turn may potentiate the initiation and progression of lesions in the aging kidney.