Stimulation of Ca<sup>2+</sup> influx through ATP receptors on rat brain synaptosomes: identification of functional P2X<sub>7</sub> receptor subtypes

Lundy, Paul M.; Hamilton, Mary G.; Mi, Lei; Gong, Wenrong; Vair, Cory; Sawyer, Thomas W.; Frew, Robert

doi:10.1038/sj.bjp.0704624

Cited by 52 publications

(34 citation statements)

References 71 publications

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“…Recent functional studies, in combination with immunolocalization using the same Abs we used in this study, have concluded that presynaptic P2X 7 receptors in the hippocampus may modulate synaptic transmission at these sites (Armstrong et al, 2002;Lundy et al, 2002;Sperlagh et al, 2002;Atkinson et al, 2004;Cavaliere et al, 2004). However, extracellular ATP activates not only ionotropic P2X receptors but also metabotropic P2Y receptors and, because it is readily broken down to adenosine, adenosine receptors.…”

Section: Discussionmentioning

confidence: 57%

“…1 A). These Abs have been used in previously published reports examining P2X 7 receptor localization and function in neuronal and nonneuronal tissues (Worthington et al, 1999a,b;Deuchars et al, 2001;Kim et al, 2001;Sluyter et al, 2001;Armstrong et al, 2002;Atkinson et al, 2002Atkinson et al, , 2004Le Feuve et al, 2002;Lundy et al, 2002;Sperlagh et al, 2002;Ishii et al, 2003). We found that Cterm-Ab, but not ectoAb-1 or ectoAb-2, were highly selective for P2X 7 receptor protein when expressed in HEK293 cells and compared with untransfected (Fig.…”

Section: Wild-type Rat and Mouse Brainmentioning

confidence: 56%

“…This hallmark has been well fulfilled in the brain for localization of P2X 4 receptors and in autonomicsensory-spinal systems for P2X 1 , P2X 2 , and P2X 3 receptors (Vulchanova et al, 1997;Le et al, 1998;Kanjhan et al, 1999;Chizh and Illes, 2000;Dunn et al, 2001;Rubio and Soto, 2001). In contrast, our inability to detect similar patterns of expression in the hippocampus and other brain areas of adult rats using the available P2X 7 Abs, as well as similar inconsistencies in the recent literature (Worthington et al, 1999a,b;Deuchars et al, 2001;Kim et al, 2001;Sluyter et al, 2001;Armstrong et al, 2002;Atkinson et al, 2002Atkinson et al, , 2004Lundy et al, 2002;Sperlagh et al, 2002;Ishii et al, 2003), led us to undertake the present study in the mouse, in which two knock-out models are available. Except for a nonspecific nuclear staining, the two commercially available Abs were, in fact, highly selective for P2X 7 receptors expressed in HEK cells and showed identical staining patterns in the submandibular gland and peripheral macrophage; moreover, all immunocytochemical staining disappeared (except for the nuclear staining with Cterm-Ab) in submandibular glands from both the GlaxoP2X 7 Ϫ/Ϫ and the Pfizer P2X 7 Ϫ/Ϫ mice.…”

Section: Discussionmentioning

confidence: 80%

“…More recently, protein expression studies revealed similar non-neuronal localizations, but these have also shown immunostaining in many brain neurons, at both presynaptic and postsynaptic densities (Deuchars et al, 2001;Armstrong et al, 2002;Atkinson et al, 2002Atkinson et al, , 2004Lundy et al, 2002;Sperlagh et al, 2002;Ishii et al, 2003;Cavaliere et al, 2004). However, immunostaining patterns in neurons have been inconsistent (Deuchars et al, 2001;Armstrong et al, 2002;Atkinson et al, 2002;Sperlagh et al, 2002;Ishii et al, 2003;Lundy et al, 2003;Atkinson et al, 2004).…”

Section: Introductionmentioning

confidence: 97%

“…We examined most areas of the brain but focused our studies on the hippocampus because this is the region where most of the current evidence for the functional ex-pression of the P2X 7 receptor has been obtained (Deuchars et al, 2001;Armstrong et al, 2002;Lundy et al, 2002;Sperlagh et al, 2002;Atkinson et al, 2004). We performed immunocytochemistry, Western blotting, and immunoprecipitation experiments using three separate Abs directed at different epitopes of the P2X 7 protein and on two sets of P2X 7 receptor knock-out mice generated using different strategies.…”

Section: Introductionmentioning

confidence: 99%

See 4 more Smart Citations

Reanalysis of P2X₇Receptor Expression in Rodent Brain

Sim¹,

Young²,

Sung³

et al. 2004

J. Neurosci.

241

211

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P2X receptors are cationic-selective ion channels gated by extracellular ATP. There are seven subunits (P2X 1-7 ), the first six of which are expressed throughout the peripheral and central nervous systems. P2X 7 receptors are rapidly upregulated and activated as a result of inflammatory stimuli in immune cells, where they act not only as cationic channels but uniquely couple with rapid release of proinflammatory cytokines, cytoskeletal rearrangements, and apoptosis or necrotic cell death. The P2X 7 receptor has been termed the cytolytic non-neuronal P2X receptor because it had not been detected in neurons until recently when it has been immunolocalized to several brain regions, particularly the hippocampus, and has been suggested to be involved in presynaptic modulation of transmitter release. Because its expression in brain neurons may have substantial functional implications, we have performed detailed immunocytochemical, immunoblot, and immunoprecipitation studies on brain and non-neuronal tissue using all currently available antibodies. We first examined rats, but staining patterns were inconsistent among antibodies; we therefore studied mice for which there are two P2X 7 knock-out mice constructs available, one expressing the LacZ transgene. We found that P2X 7 receptor protein is strongly and reliably detected in the submandibular gland and lung of wild-type mice but not in either of the P2X 7 Ϫ/Ϫ mice. However, we failed to find evidence for P2X 7 receptor protein in hippocampal neurons or their input-output projections. Either the P2X 7 protein in the hippocampus is below the limits of detection by the currently available methods or it is not present.

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Section: Discussionmentioning

confidence: 57%

Section: Wild-type Rat and Mouse Brainmentioning

confidence: 56%

Section: Discussionmentioning

confidence: 80%

Section: Introductionmentioning

confidence: 97%

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Reanalysis of P2X₇Receptor Expression in Rodent Brain

Sim¹,

Young²,

Sung³

et al. 2004

J. Neurosci.

241

211

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Strong P2X₄ purinergic receptor‐like immunoreactivity is selectively associated with degenerating neurons in transgenic rodent models of amyotrophic lateral sclerosis

Casanovas

Hernández

Tarabal

et al. 2007

J of Comparative Neurology

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The distribution of the P2X family of ATP receptors was analyzed in a rat model for amyotrophic lateral sclerosis (ALS) expressing mutated human superoxide dismutase (mSOD1(G93A)). We showed that strong P2X(4) immunoreactivity was selectively associated with degenerating motoneurons (MNs) in spinal cord ventral horn. Degenerating P2X(4)-positive MNs did not display apoptotic features such as chromatin condensation, positive TUNEL reaction, or active caspase 3 immunostaining. In contrast, these neurons showed other signs of abnormality, such as loss of the neuronal marker NeuN and recruitment of microglial cells with neuronophagic activity. Similar changes were observed in MNs from the cerebral cortex and brainstem in mSOD1(G93A) in both rat and mice. In addition, P2X(4) immunostaining demonstrated the existence of neuronal degeneration in the locus coeruleus, reticular formation, and Purkinje cells of the cerebellar cortex. It is suggested that abnormal trafficking and proteolytic processing of the P2X(4) receptor protein may underlie these changes.

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Increase of intracellular Ca²⁺ by P2Y but not P2X receptors in cultured cortical multipolar neurons of the rat

Fischer¹,

Nörenberg²,

Franke³

et al. 2009

J of Comparative Neurology

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The expression and functionality of P2X/P2Y receptor subtypes in multipolar nonpyramidal neurons of mixed cortical cell cultures were investigated by means of immunocytochemistry and fura-2 microfluorimetry. The morphological studies revealed that most of the neurons are immunoreactive for GABA and express a range of P2X/P2Y receptors, predominantly of the P2X(2,4,6) and P2Y(1,2) subtypes. P2X(1) and P2X(7) receptor immunoreactivity (IR) was found on thin axon-like processes and presynaptic structures, respectively. Application of ATP caused a small concentration-dependent increase in intracellular Ca2+ concentration ([Ca2+]i) in most investigated neurons, whereas only about the half of these cells responded to 2',3'-O-(benzoyl-4-benzoyl)-ATP (BzATP), ADPbetaS, 2MeSADP, or 2MeSATP and even fewer cells to UTP. In contrast, alpha,beta-meATP, UDP, and UDP-glucose failed to produce any [Ca2+]i signaling. The response to ATP itself was inhibited by pyridoxal-5'-phosphate-6-azophenyl-2',4'-disulfonic acid (PPADS), Reactive Blue 2, 2'-deoxy-N(6)-methyl adenosine 3',5'-diphosphate (MRS2179), and suramin (300 microM) as well as by a cyclopiazonic acid-induced depletion of intracellular Ca2+ stores. A Ca2+-free external medium tended to decrease the ATP-induced [Ca2+]i transients, although this action did not reach statistical significance. Various blockers of voltage-sensitive Ca2+ channels and the gap junction inhibitor carbenoxolone did not interfere with the effect of ATP, whereas a combination of the ionotropic glutamate receptor antagonists D(-)-2-amino-5-phosphonopentanoic acid (AP5) and 6-cyano-7-nitroquinoxaline-2,3-dione (CNQX) decreased it. Cross-desensitization experiments between ADPbetaS or UTP and ATP suggested that ATP acts on the one hand via P2Y(1,2) receptors and on the other hand by additional signaling mechanisms. These mechanisms may involve the release of glutamate (which in consequence activates ionotropic glutamate receptors) and the entry of Ca2+ via store-operated Ca2+ channels. Evidence for the presence of functional P2X receptors, in particular P2X(7), remains elusive.

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Stimulation of Ca²⁺ influx through ATP receptors on rat brain synaptosomes: identification of functional P2X₇ receptor subtypes

Cited by 52 publications

References 71 publications

Reanalysis of P2X₇Receptor Expression in Rodent Brain

Reanalysis of P2X₇Receptor Expression in Rodent Brain

Strong P2X₄ purinergic receptor‐like immunoreactivity is selectively associated with degenerating neurons in transgenic rodent models of amyotrophic lateral sclerosis

Increase of intracellular Ca²⁺ by P2Y but not P2X receptors in cultured cortical multipolar neurons of the rat

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Stimulation of Ca2+ influx through ATP receptors on rat brain synaptosomes: identification of functional P2X7 receptor subtypes

Cited by 52 publications

References 71 publications

Reanalysis of P2X7Receptor Expression in Rodent Brain

Reanalysis of P2X7Receptor Expression in Rodent Brain

Strong P2X4 purinergic receptor‐like immunoreactivity is selectively associated with degenerating neurons in transgenic rodent models of amyotrophic lateral sclerosis

Increase of intracellular Ca2+ by P2Y but not P2X receptors in cultured cortical multipolar neurons of the rat

Contact Info

Product

Resources

About

Stimulation of Ca²⁺ influx through ATP receptors on rat brain synaptosomes: identification of functional P2X₇ receptor subtypes

Reanalysis of P2X₇Receptor Expression in Rodent Brain

Reanalysis of P2X₇Receptor Expression in Rodent Brain

Strong P2X₄ purinergic receptor‐like immunoreactivity is selectively associated with degenerating neurons in transgenic rodent models of amyotrophic lateral sclerosis

Increase of intracellular Ca²⁺ by P2Y but not P2X receptors in cultured cortical multipolar neurons of the rat