Ligands of Receptor for Advanced Glycation End-Products Produced by Activated Microglia are Critical in Neurodegenerative Diseases

Abstract

Receptor for advanced glycation end products (RAGE) and its ligands have been reported to be involved in the progressions of neurodegenerative diseases, including Alzheimer’s and Parkinson’s disease. Recently microglia activated by immunological stimuli, cytokines, or oxidative stress were reported to synthesize and secrete RAGE ligands including AGEs, HMGB1, and S100 in neurodegenerative diseases. Furthermore, RAGE/ligand binding has been implicated in neuroinflammation and in the progression of neurodegenerative diseases through a RAGEmediated pathway in neurons. A number of RAGE inhibitors, such as, antagonists, small RAGE inhibitors, anti-RAGE antibody, and soluble RAGE, have been shown to interfere with RAGE/ligand binding and to reduce RAGE ligand accumulation, microglia activation, and neuronal cell death in neurodegenerative diseases. Accordingly, RAGE inhibitors present an attractive therapeutic target in neurodegenerative diseases, and RAGE ligands might be useful diagnostic targets. Some human studies have shown RAGE ligand distributions in brain, serum, and cerebrospinal fluid are promising biomarkers for early disease detection and that these ligands might play important roles during early disease stages. Taken together, RAGE ligands and RAGE inhibitors appear to be good therapeutic and diagnostic candidates for neurodegenerative diseases.