Brain Pericytes As Mediators of Neuroinflammation

Pericytes in the brain and spinal cord constitute a new class of cell mediating inflammation in the nervous system. Capillary pericytes control the movement of peripheral immune cells into the nervous system and show significant phagocytic activity associated with clearance of toxic proteins. Pericytes may assume a microglia-like phenotype under some conditions. Capillary pericytes regulate the formation and stability of the blood–brain barrier and the blood–spinal cord barrier and their dysfunction is associated with leakage through these barriers. Immune modulators elicit the release of a plethora of inflammatory mediators from pericytes that may be responsible for the disruption of barriers in the brain and spinal cord. Immune modulators such as interferon gamma impair pericyte function by preventing signalling through platelet-derived growth factor receptor beta, which is critical for the proliferation and survival of these cells. Brain pericytes are perivascular cells that regulate capillary function, and this localization puts them in a pivotal position for the regulation of central nervous system (CNS) inflammatory responses at the neurovascular unit. Neuroinflammation, driven by microglia and astrocytes or resulting from peripheral leukocyte infiltration, has both homeostatic and detrimental consequences for brain function and is present in nearly every neurological disorder. More recently, brain pericytes have been shown to have many properties of immune regulating cells, including responding to and expressing a plethora of inflammatory molecules, presenting antigen, and displaying phagocytic ability. In this review we highlight the emerging role of pericytes in neuroinflammation and discuss pericyte-mediated neuroinflammation as a potential therapeutic target for the treatment of a range of devastating brain disorders. Brain pericytes are perivascular cells that regulate capillary function, and this localization puts them in a pivotal position for the regulation of central nervous system (CNS) inflammatory responses at the neurovascular unit. Neuroinflammation, driven by microglia and astrocytes or resulting from peripheral leukocyte infiltration, has both homeostatic and detrimental consequences for brain function and is present in nearly every neurological disorder. More recently, brain pericytes have been shown to have many properties of immune regulating cells, including responding to and expressing a plethora of inflammatory molecules, presenting antigen, and displaying phagocytic ability. In this review we highlight the emerging role of pericytes in neuroinflammation and discuss pericyte-mediated neuroinflammation as a potential therapeutic target for the treatment of a range of devastating brain disorders.