ATP evokes Ca2+ signals in cultured foetal human cortical astrocytes entirely through protien-coupled P2Y receptors

作者：Muller Margit S; Taylor Colin W^*

来源：Journal of Neurochemistry, 2017, 142(6): 876-885.

DOI：10.1111/jnc.14119

• P2X receptor
• P2Y(1) receptor
• P2Y(2) receptor
• phospholipase C
• purinoceptor
• store-operated Ca2+ entry

Extracellular ATP plays important roles in coordinating the activities of astrocytes and neurons, and aberrant signalling is associated with neurodegenerative diseases. In rodents, ATP stimulates opening of Ca2+-permeable channels formed by P2X receptor subunits in the plasma membrane. It is widely assumed, but not verified, that P2X receptors also evoke Ca2+ signals in human astrocytes. Here, we directly assess this hypothesis. We showed that cultured foetal cortical human astrocytes express mRNA for several P2X receptor subunits (P2X(4), P2X(5), P2X(6)) and G protein-coupled P2Y receptors (P2Y(1), P2Y(2), P2Y(6), P2Y(11)). In these astrocytes, ATP stimulated Ca2+ release from intracellular stores through IP3 receptors and store-operated Ca2+ entry. These responses were entirely mediated by P2Y(1) and P2Y(2) receptors. Agonists of P2X receptors did not evoke Ca2+ signals, and nor did ATP when Ca2+ release from intracellular stores and store-operated Ca2+ entry were inhibited. We conclude that ATPevoked Ca2+ signals in cultured human foetal astrocytes are entirely mediated by P2Y(1) and P2Y(2) receptors, with no contribution from P2X receptors.

• 出版日期2017-9