The receptor for advanced glycation end products (RAGE) is member of the immunoglobulin (Ig) superfamily. It can be expressed as full-length, membrane-bound RAGE isoform 1 or as a secreted sRAGE protein that lacks a transmembrane domain (1). RAGE is detected during early developmental stages and in the lung under normal physiological conditions (2) and is upregulated at sites of inflammation (3). Advanced glycation end products (AGEs) and a variety of other ligands interact with this receptor (1). Ligand binding activates full-length RAGE and initiates downstream signaling pathways that include activation of NF-κB, which leads to production of pro-inflammatory cytokines and inflammation (4). Activation of these pathways has been implicated in various disease states including Alzheimer disease, diabetes, arthritis, and atherosclerosis (4). Soluble RAGE can competitively bind RAGE ligands in the extracellular environment, which prevents ligand interaction with full-length RAGE at the cell surface (1).
