M ultiple sclerosis is a chro nic central nervous system demyelinating disease whose onset and progression are driven by a combination of immune dysregulation,genetic predisposition,and environmental fa ctors.The acti...M ultiple sclerosis is a chro nic central nervous system demyelinating disease whose onset and progression are driven by a combination of immune dysregulation,genetic predisposition,and environmental fa ctors.The activation of microglia and astrocytes is a key player in multiple sclerosis immunopathology,playing specific roles associated with anatomical location and phase of the disease and controlling demyelination and neurodegeneration.Even though reactive mic roglia can damage tissue and heighten deleterious effects and neurodegeneration,activated microglia also perform neuroprotective functions such as debris phagocytosis and growth fa ctor secretion.Astrocytes can be activated into pro-inflammato ry phenotype A1 through a mechanism mediated by activated neuroinflammatory microglia,which could also mediate neurodegeneration.This A1 phenotype inhibits oligodendrocyte prolife ration and differe ntiation and is toxic to both oligodendrocytes and neurons.Howeve r,astroglial activation into phenotype A2 may also take place in response to neurodegeneration and as a protective mechanism.A variety of animal models mimicking specific multiple sclerosis features and the associated pathophysiological processes have helped establish the cascades of events that lead to the initiation,progression,and resolution of the disease.The colonystimulating facto r-1 receptor is expressed by myeloid lineage cells such as peripheral monocytes and macrophages and central nervous system microglia.Importantly,as microglia development and survival critically rely on colony-stimulating factor-1 receptor signaling,colony-stimulating factor-1 receptor inhibition can almost completely eliminate microglia from the brain.In this context,the present review discusses the impact of microglial depletion through colo ny-stimulating factor-1 receptor inhibition on demyelination,neurodegeneration,astroglial activation,and behavior in different multiple sclerosis models,highlighting the diversity of microglial effects on the progression of demyelinating diseases and the strengths and weaknesses of microglial modulation in therapy design.展开更多
文摘M ultiple sclerosis is a chro nic central nervous system demyelinating disease whose onset and progression are driven by a combination of immune dysregulation,genetic predisposition,and environmental fa ctors.The activation of microglia and astrocytes is a key player in multiple sclerosis immunopathology,playing specific roles associated with anatomical location and phase of the disease and controlling demyelination and neurodegeneration.Even though reactive mic roglia can damage tissue and heighten deleterious effects and neurodegeneration,activated microglia also perform neuroprotective functions such as debris phagocytosis and growth fa ctor secretion.Astrocytes can be activated into pro-inflammato ry phenotype A1 through a mechanism mediated by activated neuroinflammatory microglia,which could also mediate neurodegeneration.This A1 phenotype inhibits oligodendrocyte prolife ration and differe ntiation and is toxic to both oligodendrocytes and neurons.Howeve r,astroglial activation into phenotype A2 may also take place in response to neurodegeneration and as a protective mechanism.A variety of animal models mimicking specific multiple sclerosis features and the associated pathophysiological processes have helped establish the cascades of events that lead to the initiation,progression,and resolution of the disease.The colonystimulating facto r-1 receptor is expressed by myeloid lineage cells such as peripheral monocytes and macrophages and central nervous system microglia.Importantly,as microglia development and survival critically rely on colony-stimulating factor-1 receptor signaling,colony-stimulating factor-1 receptor inhibition can almost completely eliminate microglia from the brain.In this context,the present review discusses the impact of microglial depletion through colo ny-stimulating factor-1 receptor inhibition on demyelination,neurodegeneration,astroglial activation,and behavior in different multiple sclerosis models,highlighting the diversity of microglial effects on the progression of demyelinating diseases and the strengths and weaknesses of microglial modulation in therapy design.
