Abstract
In this work, we mainly used the organotypic model of rat hippocampus to demonstrate the protective role of the P2 receptor antagonist trinitrophenyl-adenosine-triphosphate (TNP-ATP) during oxygen/glucose deprivation. Among the P2X receptors that TNP-ATP specifically blocks, mainly P2X1 seems to be involved in the processes of cell damage after oxygen/glucose deprivation. P2X1 receptor is strongly and transiently up-regulated in 24 h after an ischemic insult on structures likely corresponding to mossy fibers and Schaffer collaterals of CA1–3 and dentate gyrus. Furthermore, P2X1 receptor is down-regulated by pharmacological treatment with TNP-ATP, which is also found neuroprotective against ischemic cell death. Morphological studies conducted through immunofluorescence and confocal analysis in primary organotypic, in dissociated cultures, and in adult rat in vivo demonstrated the neuronal colocalization of P2X1 protein with neurofilament light chain and neuronal nuclei immunoreactivity in myelinated and unmyelinated fibers of both granular and pyramidal neurons. In conclusion, with this work, we proved the neuronal distribution of P2X1 receptor in hippocampus, and we presented evidence for a potential disadvantageous role of its expression during the path of in vitro ischemia.
Footnotes
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This work was supported by Ministero dell'Istruzione, dell'Università e della Ricerca project “Purinoceptors and Neuroprotection” and Grant RF05.105V from Ministero della Salute (to C.V.) and by Marie Curie development host fellowship program contract MCFH-2001-00639 (to F.C. and K.R.).
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Article, publication date, and citation information can be found at http://jpet.aspetjournals.org.
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doi:10.1124/jpet.106.119024.
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ABBREVIATIONS: P2r, purinergic receptor(s); CNS, central nervous system; PNS, peripheral nervous system; OGD, oxygen/glucose deprivation; TNP-ATP, trinitrophenyl-adenosine-triphosphate; PBS, phosphate-buffered saline; NFL, neurofilament light; GFM, glucose-free medium; Ib4, isolectin b4; GFAP, glial fibrillary acidic protein; MBP, myelin basic protein; PI, propidium iodide; DG, dentate gyrus; mf, mossy fibers; sc, Schaffer collateral fibers; NeuN, neuronal nuclei.
- Received January 4, 2007.
- Accepted July 6, 2007.
- The American Society for Pharmacology and Experimental Therapeutics
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