X chromosome drive

How are toxic proteins cleared by microglia? Since microglia are the macrophages of the CNS, the promotion of an increase in their ability to phagocytose highly toxic proteins is a promising new therapeutic approach to prevent many diseases. Toxic proteins are produced in a variety of brain diseases, such as Alzheimer’s disease (b-amyloid), amyotrophic lateral sclerosis (superoxide dismutase 1), and Parkinson’s disease (a-synuclein). Microglia are recruited in such conditions, but they are not necessarily efficient at phagocytosis and removal of these toxic proteins from the extracellular environment. In the case of Alzheimer’s disease, increasing the infiltration of bloodderived microglial cells seems likely to be a useful therapeutic approach, since these cells are able to eliminate or prevent the formation of b-amyloid deposits. Immunization against bamyloid stimulates the recruitment of bone-marrow-derived microglia and improves both the clearance of the protein and cognitive function. It is tempting to propose that such a strategy could also be efficient in clearing secreted and toxic proteins involved in many other diseases that affect the CNS.