Induction of novel cytokines and chemokines by advanced glycation endproducts determined with a cytometric bead array

Advanced glycation endproducts (AGEs) accumulate on long-lived protein deposits, e.g. those composed of beta(2)-microglobulin (in dialysis-related amyloidosis) or P-amyloid peptide (in Alzheimer's disease). When AGEs bind to the "receptor for advanced glycation endproducts", they activate redox-sensitive transcription factors such as NF-kappa B, and subsequently induce the expression of pro-inflammatory cytokines such as IL-1, IL-6 and TNF-alpha. Using a cytokine bead array, we have further analyzed the Bovine Serum Albumin (BSA)-AGE induced expression of selected cytokines/chemokines in two murine cell lines, RAW 264.7 macrophages and N-11 microglia. Our study showed that monocyte chemoattractant protein-1 (MCP-1) and tumor necrosis factor (TNF-alpha) were both released in a time-dependent manner from both RAW 264.7 macrophages and N-11 microglia upon stimulation with BSA-AGE or lipopolysaccharide (LPS), which was used as a positive control. Interestingly, MCP-1 was also constitutively expressed by unstimulated cells, although at a lower levels. Much higher levels of IL-6 were secreted by RAW 264.7 macrophages than by N-11 microglia in response to both stimuli. IL-12p70, interferon-gamma and the anti-inflammatory cytokine IL-10 were not induced by either LPS or BSA-AGE. Our results indicate a very similar pattern of chemokine and cytokine expression induced by such different ligands as AGEs and LPS indicating similar or convergent downstream signaling pathways. (c) 2007 Elsevier Ltd. All rights reserved.