Angelova Plamena R, Baev Artyom Y, Berezhnov Alexey V, Abramov Andrey Y
Department of Molecular Neuroscience, UCL Institute of Neurology, Queen Square, WC1N 3BG London, U.K.
Faculty of Biology and Soil Science, National University of Uzbekistan, Tashkent 100174, Uzbekistan.
Biochem Soc Trans. 2016 Feb;44(1):40-5. doi: 10.1042/BST20150223.
Inorganic polyphosphate (polyP) is a polymer compromised of linearly arranged orthophosphate units that are linked through high-energy phosphoanhydride bonds. The chain length of this polymer varies from five to several thousand orthophosphates. PolyP is distributed in the most of the living organisms and plays multiple functions in mammalian cells, it is important for blood coagulation, cancer, calcium precipitation, immune response and many others. Essential role of polyP is shown for mitochondria, from implication into energy metabolism and mitochondrial calcium handling to activation of permeability transition pore (PTP) and cell death. PolyP is a gliotransmitter which transmits the signal in astrocytes via activation of P2Y1 receptors and stimulation of phospholipase C. PolyP-induced calcium signal in astrocytes can be stimulated by different lengths of this polymer but only long chain polyP induces mitochondrial depolarization by inhibition of respiration and opening of the PTP. It leads to induction of astrocytic cell death which can be prevented by inhibition of PTP with cyclosporine A. Thus, medium- and short-length polyP plays role in signal transduction and mitochondrial metabolism of astrocytes and long chain of this polymer can be toxic for the cells.
无机多聚磷酸盐（polyP）是一种由通过高能磷酸酐键连接的线性排列的正磷酸盐单元组成的聚合物。这种聚合物的链长从五个到数千个正磷酸盐不等。PolyP分布于大多数生物体内，在哺乳动物细胞中发挥多种功能，对血液凝固、癌症、钙沉淀、免疫反应等诸多方面都很重要。PolyP在线粒体中显示出重要作用，从参与能量代谢和线粒体钙处理到激活通透性转换孔（PTP）和细胞死亡。PolyP是一种神经胶质递质，通过激活P2Y1受体和刺激磷脂酶C在星形胶质细胞中传递信号。不同长度的这种聚合物都能刺激星形胶质细胞中由PolyP诱导的钙信号，但只有长链PolyP通过抑制呼吸和打开PTP诱导线粒体去极化。这会导致星形胶质细胞死亡，而用环孢素A抑制PTP可以预防这种情况。因此，中短链PolyP在星形胶质细胞的信号转导和线粒体代谢中起作用，而这种聚合物的长链可能对细胞有毒。
