ATP-induced non-neuronal cell permeabilization in the rat inner retina
ATP-induced non-neuronal cell permeabilization in the rat inner retina
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DOI：
10.1523/jneurosci.2812-04.2004
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发表时间：
2004-09-29
影响因子：
5.3
通讯作者：
Guenther, E
中科院分区：
文献类型：
--
作者：
Innocenti, B;Pfeiffer, S;Guenther, E
The P2X(7) subtype holds a special position among P2X receptors because of its ability to act both as a classical, ligand-gated ion channel, and as a permeabilization pore that can induce cell death under prolonged activation by ATP.We have shown previously that, in rat retina, P2X(7) receptors are located in the inner nuclear layer and ganglion cell layer (GCL). The present study was aimed at finding whether retinal P2X(7) receptors can act as a mediator of cell permeabilization and, if so, at identifying the cellular target(s) of this effect.As an indicator of cell permeabilization, we used the fluorescent dye YO-PRO-1 (molecular weight, 375 Da), which enters cells only through large pores like those opened by prolonged or sustained stimulation of P2X(7) receptors and binds to DNA, providing a stable labeling of the activated cells.Different agonists for P2 receptors were tested for their ability to cause cell permeabilization in flat-mounted rat retinas. Among them, only high concentrations of ATP (500 muM) and BzATP (2',3'-O-(4-benzoyl-benzoyl)-ATP triethylammonium) (100 muM) were able to induce accumulation of YO-PRO-1 in the GCL and in the nerve fiber layer, suggesting that different cell types were responding to P2X(7) stimulation. This effect was blocked by the P2 antagonists suramin and PPADS (pyridoxal-phosphate-6-azophenyl-2',4'-disulfonic acid) and by the P2X(7)-selective inhibitor Brilliant Blue G.To identify the retinal cell types affected by ATP-induced permeabilization, we used in vivo labeling techniques. Our data clearly reveal that prolonged stimulation of P2X(7) receptors elicits permeabilization exclusively in microglial cells but not in neurons of the inner retina.
