RESUMO
Receptor for AGE (RAGE) is a member of the immunoglobulin superfamily that engages distinct classes of ligands. The biology of RAGE is driven by the settings in which these ligands accumulate, such as diabetes, inflammation, neurodegenerative disorders and tumors. In this review, we discuss the context of each of these classes of ligands, including advance glycation end-products, amyloid beta peptide and the family of beta sheet fibrils, S100/calgranulins and amphoterin. Implications for the role of these ligands interacting with RAGE in homeostasis and disease will be considered.
Assuntos
Receptores Imunológicos/fisiologia , Doença de Alzheimer/etiologia , Amiloidose/etiologia , Animais , Arteriosclerose/etiologia , Arteriosclerose/metabolismo , Arteriosclerose/patologia , Movimento Celular , Doença Crônica , Angiopatias Diabéticas/etiologia , Angiopatias Diabéticas/metabolismo , Angiopatias Diabéticas/patologia , Homeostase , Humanos , Imunoglobulinas/classificação , Inflamação/etiologia , Camundongos , Neoplasias/etiologia , Neoplasias/patologia , Receptor para Produtos Finais de Glicação Avançada , Receptores Imunológicos/metabolismo , Transdução de SinaisRESUMO
Receptor for advanced glycation end-products (RAGE), and two of its ligands, AGE and EN-RAGEs (members of the S100/calgranulin family of pro-inflammatory cytokines), display enhanced expression in slowly resolving full-thickness excisional wounds developed in genetically diabetic db+/db+ mice. We tested the concept that blockade of RAGE, using soluble(s) RAGE, the extracellular ligand-binding domain of the receptor, would enhance wound closure in these animals. Administration of sRAGE accelerated the development of appropriately limited inflammatory cell infiltration and activation in wound foci. In parallel with accelerated wound closure at later times, blockade of RAGE suppressed levels of cytokines; tumor necrosis factor-alpha; interleukin-6; and matrix metalloproteinases-2, -3, and -9. In addition, generation of thick, well-vascularized granulation tissue was enhanced, in parallel with increased levels of platelet-derived growth factor-B and vascular endothelial growth factor. These findings identify a central role for RAGE in disordered wound healing associated with diabetes, and suggest that blockade of this receptor might represent a targeted strategy to restore effective wound repair in this disorder.