P2Y6 Receptors Regulate CXCL10 Expression and Secretion in Mouse Intestinal Epithelial Cells

Abstract

In this study, we investigated the role of extracellular nucleotides in chemokine (KC, MIP-2, MCP-1, and CXCL10) expression and secretion by murine primary intestinal epithelial cells (IECs) with a focus on P2Y6 receptors. qRT-PCR experiments showed that P2Y6 was the dominant nucleotide receptor expressed in mouse IEC. In addition, the P2Y6 ligand UDP induced expression and secretion of CXCL10. For the other studies, we took advantage of mice deficient in P2Y6 (P2ry6-/-). Similar expression levels of P2Y1, P2Y2, P2X2, P2X4, and A2A were detected in P2ry6-/- and WT IEC. Agonists of TLR3 (poly(I:C)), TLR4 (LPS), P2Y1, and P2Y2 increased the expression and secretion of CXCL10 more prominently in P2ry6-/- IEC than in WT IEC. CXCL10 expression and secretion induced by poly(I:C) in both P2ry6-/- and WT IEC were inhibited by general P2 antagonists (suramin and Reactive-Blue-2), by apyrase, and by specific antagonists of P2Y1, P2Y2, P2Y6 (only in WT), and P2X4. Neither adenosine nor an A2A antagonist had an effect on CXCL10 expression and secretion. Macrophage chemotaxis was induced by the supernatant of poly(I:C)-treated IEC which was consistent with the level of CXCL10 secreted. Finally, the non-nucleotide agonist FGF2 induced MMP9 mRNA expression also at a higher level in P2ry6-/- IEC than in WT IEC. In conclusion, extracellular nucleotides regulate CXCL10 expression and secretion by IEC. In the absence of P2Y6, these effects are modulated by other P2 receptors also present on IEC. These data suggest that the presence of P2Y6 regulates chemokine secretion and may also regulate IEC homeostasis.

Extracellular Adenosine Diphosphate Stimulates CXCL10-Mediated Mast Cell Infiltration Through P2Y1 Receptor to Aggravate Airway Inflammation in Asthmatic Mice

“…Indeed, a recent work confirmed that extracellular ADP acts on the P2Y12 receptor to potentiate activation of the NF-κB signaling pathway during microglial inflammation ( Suzuki et al, 2020 ). In accordance with this finding, the expression of CXCL10 has been observed to be reduced by specific antagonists of P2Y1 ( Salem et al, 2018 ). Meanwhile, the mRNA expression and secretion of CXCL10 in ASMCs have been detected to be increased after stimulation with ATP ( Gao et al, 2014 ).…”

The expression of P2Y6 receptor promotes the quality of mucus in colitic mice

“…Our results suggest that goblet cells rapidly discharged mucins to compensate for the lability of the mucus layer. Hence, the absence of the Gα q ‐coupled P2Y 6 receptor expression, one of the major P2Y receptors expressed by intestinal epithelial cells [32], could have led to an alteration in the mobilization of intracellular calcium, an essential factor contributing to mucin packaging and secretion [22,60,61]. Additional experiments will be required to validate this idea and elucidate the cellular mechanism linking the P2Y 6 receptor activity to mucus quality modulation.…”

“…However, in the DSS mouse model of colitis, the receptor expression was increased. Its activity induced the secretion of C‐X‐C motif chemokine ligand 8 and C‐X‐C motif chemokine ligand 10 by intestinal epithelial cells and the subsequent recruitment of neutrophils and macrophages [31,32]. The activity of this receptor also provides resistance to apoptosis for intestinal epithelial cells [33], osteoclasts [34], and skeletal muscle cells [35] while stimulating epithelial cell migration [36,37].…”

Associations of P2RX7 Functional Diplotypes with Localized Aggressive Periodontitis

“…The significant difference in IP-10 levels between the HUC and LAP groups with loss of function diplotypes was novel because there is little evidence directly linking the production of IP-10 with LPS/ TLR4 stimulation of the P2X7 receptor. However, a recent article reported that the expression and secretion of IP-10 can be induced through UDP-activated P2Y6 receptor activity (Salem et al 2018), which is also a purinergic G protein-coupled receptor. Another study found that TLR4 stimulation (such as that from the LPS) induces production of not only ATP but also UDP, the primary agonist for the P2Y6 receptor (Dosch et al 2018).…”