P2Y13 receptor is responsible for ADP-mediated degranulation in RBL-2H3 rat mast cells

Abstract

Extracellular ADP is known to play many important physiological roles. In this study, we identified the P2Y13 receptor in a rat mast cell line (RBL-2H3) and explored the functional role of ADP, its endogenous agonist. ADP induced both intracellular calcium mobilization and release of hexosaminidase (Hex). In an assay of intracellular calcium, ADP was 100-fold less potent than and equally efficacious as the P2Y1 receptor-selective agonist MRS2365. However, ADP was more potent and efficacious than MRS2365 in inducing Hex release and in enhancing antigen-induced Hex release. ADP-induced intracellular calcium mobilization was blocked by phospholipase C inhibitor U73122 and by P2Y1 receptor selective antagonist MRS2500, but not by pertussis toxin (PTX), suggesting a mechanism mediated by the Gq-coupled P2Y1 receptor, but not P2Y13 (Gi-coupled) or P2X receptors. ADP-induced Hex release was blocked by PTX and a selective P2Y13 receptor antagonist MRS2211, but not by MRS2500 or P2Y1 receptor-specific siRNA, suggesting a Gi-coupled P2Y13 receptor-related mechanism. Measurement of gene expression confirmed high expression of both P2Y1 and P2Y13 receptors (in comparison to a previously reported P2Y14 receptor) in RBL-2H3 cells. Thus, we demonstrated that ADP-mediated intracellular calcium mobilization and Hex release in RBL-2H3 cells are via P2Y1 and P2Y13 receptors, respectively. Selective antagonists of the P2Y13 receptor might be novel therapeutic agents for various allergic conditions.

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

“…Schulman et al confirmed the presence of P2Y 1 and P2Y 2 , but not P2X7 transcript in HLMC's as discussed above. Recent studies indicate that P2Y 13 and P2Y 14 might also be involved in mast cell degranulation, since these receptors induce β-hexosaminidase release in RBL-2H3 rat mast cells [215,221] while P2Y 14 was also reported to potentiate C3a-induced β-hexosaminidase release in human LAD2 cells [216] (Table 1). Triggering of intracellular Ca 2+ signaling in mast cells is also linked to cytokine expression and release.…”

“…The P2Y 11 receptor could thus be a novel potential therapeutic target for the amelioration of neutrophilic inflammation in a wide range of inflammatory diseases [35]. Another possible mechanism of action that involves to the inhibition of P2Y 11 14 receptor-activation directly induces mast cell degranulation [215,221] while P2Y 14 receptors also potentiate C3a-induced degranulation [216]. DAMP damage-associated molecular patterns, PAMP pathogen-associated molecular patterns, C3a complement 3a, C3aR complement 3a receptor.…”

The role of P2Y14 and other P2Y receptors in degranulation of human LAD2 mast cells

“…The ability of activation of certain receptors to enhance antigen-mediated degranulation led to the suggestion that under some conditions; these receptors have the capacity to contribute to allergic responses in vivo [1]. The class of receptors for extracellular nucleotides comprises eight GPCRs (P2Y 1,2,4,6,11,12,13,14 ) and seven LGICs (P2X 1-7 ), many of which being expressed in blood cells [6]. The roles of P2 receptors in mast cell biology have recently been reviewed [7].…”

“…Nucleotides, especially adenosine 5′-diphosphate (ADP) and adenosine 5′-triphosphate (ATP), have been studied previously in the context of mast cell degranulation [9,10], but specific receptor subtypes mediating these functions have not been systematically explored. We recently demonstrated in RBL-2H3 basophillic cells, a degranulation model of rat mast cells, that P2Y 13 R and P2Y 14 R are involved in degranulation [11,12]. However, the role of various P2YRs in human mast cells has been largely unexplored, although isolated studies indicate the possible involvement of certain P2YRs [10,13].…”

The enteric nervous system of P2Y13 receptor null mice is resistant against high-fat-diet- and palmitic-acid-induced neuronal loss

“…P2Y 13 is a GPCR activated by ADP and coupled to G i /G o signalling [10]. It was initially identified in the spleen and brain but is also expressed in the dorsal root ganglia, microglia, pancreatic beta cells, hepatocytes and mast cells [10][11][12][13][14][15]. In central neurons, P2Y 13 has been shown to be involved in neuronal differentiation, axonal elongation, oxidative stress and inflammatory pain behaviour [11,[16][17][18].…”