Calcium signalling in astroglia

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• 作者：Alexei Verkhratsky^a ; ^b ; ^c ; ^{alex.verkhratsky@manchester.ac.uk} ; José ; J. Rodrí ; guez^b ; ^c ; Vladimir Parpura^b ; ^c ; ^d ; ^e ; ^vlad@uab.edu
• 关键词：Astroglia ; Calcium signalling ; Endoplasmic reticulum ; Mitochondria ; Ca2+ channels ; Ionotropic receptors
• 刊名：Molecular and Cellular Endocrinology
• 出版年：2012
• 期刊代码：109_03037207
• 类别：bio
• 出版时间：28 April, 2012
• 卷：353
• 期：1-2
• 页码：45-56
• 文件大小：973 K

摘要

Astroglia possess excitability based on movements of Ca²⁺ ions between intracellular compartments and plasmalemmal Ca²⁺ fluxes. This 鈥淐a²⁺ excitability鈥?is controlled by several families of proteins located in the plasma membrane, within the cytosol and in the intracellular organelles, most notably in the endoplasmic reticulum (ER) and mitochondria. Accumulation of cytosolic Ca²⁺ can be caused by the entry of Ca²⁺ from the extracellular space through ionotropic receptors and store-operated channels expressed in astrocytes. Plasmalemmal Ca²⁺ ATP-ase and sodium-calcium exchanger extrude cytosolic Ca²⁺ to the extracellular space; the exchanger can also operate in reverse, depending of the intercellular Na⁺ concentration, to deliver Ca²⁺ to the cytosol. The ER internal store possesses inositol 1,4,5-trisphosphate receptors which can be activated upon stimulation of astrocytes through a multiple plasma membrane metabotropic G-protein coupled receptors. This leads to release of Ca²⁺ from the ER and its elevation in the cytosol, the level of which can be modulated by mitochondria. The mitochondrial uniporter takes up Ca²⁺ into the matrix, while free Ca²⁺ exits the matrix through the mitochondrial Na⁺/Ca²⁺ exchanger as well as via transient openings of the mitochondrial permeability transition pore. One of the prominent consequences of astroglial Ca²⁺ excitability is gliotransmission, a release of transmitters from astroglia which can lead to signalling to adjacent neurones.