Central Nervous System Diseases: Multiple Sclerosis

1303 Words5 Pages
Multiple sclerosis (MS) is a chronic inflammatory and demyelinating disease of the central nervous system (CNS). Demyelination affects white and grey matter (Kieseier and Stuve, 2011; Stadelman et al., 2011), and it is accompained by disruption of the blood-brain barrier (BBB), inflammatory infiltrates consisting of monocyte-derived macrophages and lymphocytes, and axonal degeneration (Trapp and Nave, 2008). As a consequence, MS patients usually suffer from loss of motor and sensory function, and cognitive impairment. During the disease course, especially during the early stages, MS is characterized by the succession of destruction and repair events. As lesion progress, monocytes and autoreactive T cells infiltrate the CNS. T cells are reactivated by antigen-presenting cells and secrete cytokines and chemokines that induce the recruitment and activation of macrophages, B cells and more T cells. This massive cellular infiltration and subsequent inflammation is eventually responsible of oligodendrocytes death, demyelination, and axonal degeneration. During remyelination, oligodendrocyte precursor cells (OPCs) migrate from the subventricular zone to the inflammatory lesions, proliferate and differentiate into myelin-forming oligodendrocytes. OPCs proliferation is induced by factors secreted by microglia and astrocytes that are activated by lesion formation, while OPCs survival and differentiation is established by contact between axons and OPCs processes (McQualter and Bernard,
Open Document