P2X4, P2Y1 and P2Y2 receptors on rat alveolar macrophages

Bowler, Jonathan W; Bailey, Richard J.; North, Richard; Surprenant, Annmarie

doi:10.1038/sj.bjp.0705459

Cited by 91 publications

(96 citation statements)

References 49 publications

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“…Firstly, we found that A740003 (1 mM) did not alter the currents evoked by 100 mM ATP in human alveolar macrophages (data not shown), thus confirming that this concentration of ATP was below threshold for activating P2X 7 R in these cells [21]. We have previously found that NR8383 macrophages do not express P2X 7 R under resting or LPS-stimulated conditions [22,23], thus making them a particularly attractive macrophage type in which to study P2X 4 R responses in isolation from P2X 7 R. Ivermectin (3 mM) increased mean current to 100 mM ATP by 5.3-fold in NR8383 cells (n 5 10), by 3-fold in human alveolar macrophages (n 5 10) and by 5.5-fold in mouse peritoneal macrophages (n 5 7) (Fig. 1B and C).…”

Section: P2x 4 R Protein and Functional Expression In Unstimulated Masupporting

confidence: 54%

Dynamic regulation of the P2X₄ receptor in alveolar macrophages by phagocytosis and classical activation

Stokes

Surprenant

2009

Eur J Immunol

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ATP-gated P2X 4 receptors (P2X 4 R) in macrophages and microglia have been implicated in neuropathic and inflammatory pain by currently unidentified mechanisms. P2X 4 R are found predominantly in intracellular lysosomal compartments but can be rapidly trafficked to the surface membrane by procedures that induce endolysosomal secretion. We studied total and surface membrane P2X 4 R protein expression by Western blot and biotinylation assays and functional expression by whole-cell patch clamp assays in human and rat alveolar macrophages in response to phagocytosis of zymosan and opsonized zymosan bioparticles and to classical and alternative macrophage activation. Unstimulated macrophages showed high total protein expression but very low functional expression. Phagocytosis rapidly (within 4 h) increased functional P2X 4 R expression by 2-to 7-fold as did chloroquine, an agent known to induce lysosomal secretion. In contrast, classical activation of macrophage for 48 h with IFN-c and TNF-a or IFN-c and LPS reduced surface and functional P2X 4 R expression by 3-fold without altering total P2X 4 R protein levels. Alternative activation with IL-4 or IL-13 did not alter total, surface or functional expression of P2X 4 R. This is the first study of the regulation of P2X 4 R in macrophages by physiological stimuli and presents a picture whereby P2X 4 R become functional in response to initial phagocytic stimuli but return to a non-functional state during sustained activation by classical macrophage activation.Key words: Inflammation . Ion channels . Patch-clamp . Purine receptors Introduction Extracellular ATP acts as a ''danger signal'' when it is released from cells during tissue damage and inflammation; it acts on metabotropic (G-protein coupled) P2Y and ionotropic (cation channel) P2X purinergic receptors to affect several inflammatory and immune responses [1,2]. There are seven members of the P2X receptor family (P2X 1-7 R) that show widespread distribution in both neuronal and non-neuronal tissues [3]. Two of these seven members, P2X 4 R and P2X 7 R, have generated increasing interest as potential anti-inflammatory drug targets [2,4,5]. The case for P2X 7 R is now well established: Stimulation of P2X 7 R in activated monocytes, macrophages and microglia leads to rapid release of pro-inflammatory IL-1b and IL-18 cytokines, to phospholipase D activation and, if stimulation is sustained, to apopotosis [1,[3][4][5]. Classical activation of macrophages, generally induced by IFN-g and/or LPS, up-regulates P2X 7 R mRNA and protein levels and functional expression [6,7] and this correlates well with a role for P2X 7 R in bacterial killing [8,9]. Recently, highly selective and potent P2X 7 R antagonists have been identified [10] with one of these showing initial positive results in Phase II clinical trials for rheumatoid arthritis [11]. The case for P2X 4 R remains tentative, largely due to the absence of selective P2X 4 R antagonists and the complicating presence of P2X 7 R, which is generally co-expressed with P2X 4 R in ...

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Section: P2x 4 R Protein and Functional Expression In Unstimulated Masupporting

confidence: 54%

Dynamic regulation of the P2X₄ receptor in alveolar macrophages by phagocytosis and classical activation

Stokes

Surprenant

2009

Eur J Immunol

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“…However, only P2Y 1 , P2Y 2 , P2Y 4 , P2X4, and P2X7 receptors were demonstrated to be functionally implicated in evoking ATP-mediated increases of cytosolic calcium levels [75][76][77]. In humans, alveolar macrophages were reported to express all P2 receptor subtypes except P2Y 12 , P2X2, P2X3, and P2X6 [78], whereas only, P2Y 1 , P2Y 2 , P2Y 11 , and P2X7 exhibit functional responses in inducing an intracellular calcium elevation.…”

Section: Macrophagesmentioning

confidence: 99%

Purinergic signaling in inflammatory cells: P2 receptor expression, functional effects, and modulation of inflammatory responses

Jacob

Novo

Bachert

et al. 2013

Purinergic Signalling

192

158

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Extracellular ATP and related nucleotides promote a wide range of pathophysiological responses via activation of cell surface purinergic P2 receptors. Almost every cell type expresses P2 receptors and/or exhibit regulated release of ATP. In this review, we focus on the purinergic receptor distribution in inflammatory cells and their implication in diverse immune responses by providing an overview of the current knowledge in the literature related to purinergic signaling in neutrophils, macrophages, dendritic cells, lymphocytes, eosinophils, and mast cells. The pathophysiological role of purinergic signaling in these cells include among others calcium mobilization, actin polymerization, chemotaxis, release of mediators, cell maturation, cytotoxicity, and cell death. We finally discuss the therapeutic potential of P2 receptor subtype selective drugs in inflammatory conditions.

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“…Progress has also been made in understanding the cell biology of P2X4 receptors, with evidence to suggest that they undergo endocytosis and traffic to lysosomes Royle et al, 2002;Toulmé et al, 2006;Qureshi et al, 2007;Stokes and Surprenant, 2009). Early studies showed that P2X4 receptors were widely expressed in the brain (Lê et al, 1998b;Rubio and Soto, 2001), whereas more recent studies show that they are also expressed in microglia and alveolar macrophages (Bowler et al, 2003;Tsuda et al, 2003;Raouf et al, 2007;Ulmann et al, 2008;Stokes and Surprenant, 2009).…”

Section: Surface Biotinylation Of P2x4 Receptorsmentioning

confidence: 99%

P2X4 receptors in activated C8-B4 cells of cerebellar microglial origin

Toulmé¹,

Garcia²,

Samways³

et al. 2010

J Cell Biol

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We investigated the properties and regulation of P2X receptors in immortalized C8-B4 cells of cerebellar microglial origin. Resting C8-B4 cells expressed virtually no functional P2X receptors, but largely increased functional expression of P2X4 receptors within 2-6 h of entering the activated state. Using real-time polymerase chain reaction, we found that P2X4 transcripts were increased during the activated state by 2.4-fold, but this increase was not reflected by a parallel increase in total P2X4 proteins. In resting C8-B4 cells, P2X4 subunits were mainly localized within intracellular compartments, including lysosomes. We found that cell surface P2X4 receptor levels increased by 3.5-fold during the activated state. This change was accompanied by a decrease in the lysosomal pool of P2X4 proteins. We next exploited our findings with C8-B4 cells to investigate the mechanism by which antidepressants reduce P2X4 responses. We found little evidence to suggest that several antidepressants were antagonists of P2X4 receptors in C8-B4 cells. However, we found that moderate concentrations of the same antidepressants reduced P2X4 responses in activated microglia by affecting lysosomal function, which indirectly reduced cell surface P2X4 levels. In summary, our data suggest that activated C8-B4 cells express P2X4 receptors when the membrane insertion of these proteins by lysosomal secretion exceeds their removal, and that antidepressants indirectly reduce P2X4 responses by interfering with lysosomal trafficking.

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P2X₄, P2Y₁ and P2Y₂ receptors on rat alveolar macrophages

Cited by 91 publications

References 49 publications

Dynamic regulation of the P2X₄ receptor in alveolar macrophages by phagocytosis and classical activation

Dynamic regulation of the P2X₄ receptor in alveolar macrophages by phagocytosis and classical activation

Purinergic signaling in inflammatory cells: P2 receptor expression, functional effects, and modulation of inflammatory responses

P2X4 receptors in activated C8-B4 cells of cerebellar microglial origin

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P2X4, P2Y1 and P2Y2 receptors on rat alveolar macrophages

Cited by 91 publications

References 49 publications

Dynamic regulation of the P2X4 receptor in alveolar macrophages by phagocytosis and classical activation

Dynamic regulation of the P2X4 receptor in alveolar macrophages by phagocytosis and classical activation

Purinergic signaling in inflammatory cells: P2 receptor expression, functional effects, and modulation of inflammatory responses

P2X4 receptors in activated C8-B4 cells of cerebellar microglial origin

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P2X₄, P2Y₁ and P2Y₂ receptors on rat alveolar macrophages

Dynamic regulation of the P2X₄ receptor in alveolar macrophages by phagocytosis and classical activation

Dynamic regulation of the P2X₄ receptor in alveolar macrophages by phagocytosis and classical activation