Astrocytes: regulation of brain homeostasis via apolipoprotein E.
Astrocytes are derived from the ventricular and subventricular zones of the neural plate, though there is controversy over their derivation from astrocyte-specific precursor cells or radial glia intermediates. Astrocytes are the most abundant cell type in the brain and contribute to brain homeostasis in several ways, including buffering of extracellular K+, regulating neurotransmitter release, forming the blood-brain barrier (BBB), releasing growth factors, and regulating the brain immune response. In addition, astrocytes have been shown to release apolipoprotein E (ApoE), which has been shown to regulate neurotransmission, growth factor release, and immune responses. Due to the diverse functions of astrocytes, they may play a role in a variety of diseases such as hepatic encephalopathy, multiple sclerosis, epilepsy, and age-related diseases including Alzheimer's disease and Parkinson's disease. This review highlights many of the diverse roles played by astrocytes in regulating brain homeostasis and discusses their potential role in a variety of disorders.
Gee
Jillian R
JR
Department of Anatomy and Neurobiology, University of Kentucky, 205 Sanders-Brown, 800 S. Limestone, Lexington, KY 40536-0230, USA.
Keller
Jeffrey N
JN
D000818:Animals; D001057:Apolipoproteins E / Q000096:biosynthesis / Q000502:physiology*; D001253:Astrocytes / Q000502:physiology*; D001812:Blood-Brain Barrier / Q000502:physiology; D001921:Brain / Q000502:physiology*; D004660:Encephalitis / Q000503:physiopathology; D006706:Homeostasis / Q000502:physiology*; D006801:Humans; D018377:Neurotransmitter Agents / Q000378:metabolism; D011188:Potassium / Q000378:metabolism
D001057:Apolipoproteins E; D018377:Neurotransmitter Agents; D011188:Potassium