Microglia in Health and Disease.
Microglia, the major myeloid cells of the central nervous system (CNS) are implicated in physiologic processes and in the pathogenesis of several CNS disorders. Since their initial description early in the 20th century, our ability to identify and isolate microglia has significantly improved and new research is providing insight into the functions of these cells in sickness and in health. Here, we review recent advances in our understanding of the role of microglia in physiological and pathological processes of the CNS with a focus on multiple sclerosis and Alzheimer's disease. Because of the prominent roles CX3CR1 and its ligand fractalkine played in bringing about these advances, we discuss the physiological and pathological roles of microglia as viewed from the CX3CR1-fractalkine perspective, providing a unique viewpoint. Based on the most recent studies of molecular profiling of microglia, we also propose a molecular and functional definition of microglia that incorporates the properties attributed to these cells in recent years.
Neuroinflammation Research Center, Department of Neurosciences, Cleveland Clinic Lerner Research Institute, Cleveland, Ohio 44195.
Richard M
RM
Ransohoff
Division of Infectious Diseases and Center for Immunology and Inflammatory Diseases, Massachusetts General Hospital, Harvard Medical School, Charlestown, Massachusetts 02129.
Joseph
J
El Khoury
D000544:Alzheimer Disease / Q000473:pathology; D000073883:CX3C Chemokine Receptor 1; D002493:Central Nervous System Diseases / Q000473:pathology*; D054428:Chemokine CX3CL1 / Q000235:genetics / Q000378:metabolism / Q000502:physiology; D006801:Humans; D017628:Microglia / Q000502:physiology*; D009103:Multiple Sclerosis / Q000473:pathology; D019707:Receptors, Chemokine / Q000235:genetics / Q000378:metabolism / Q000502:physiology; D015398:Signal Transduction
D000073883:CX3C Chemokine Receptor 1; C095235:CX3CR1 protein, human; D054428:Chemokine CX3CL1; D019707:Receptors, Chemokine