Salem Mabrouka, Tremblay Alain, Pelletier Julie, Robaye Bernard, Sévigny Jean
Département de Microbiologie-Infectiologie et d'Immunologie, Faculté de Médecine, Université Laval, Québec City, QC, Canada.
Centre de Recherche du CHU de Québec - Université Laval, Québec City, QC, Canada.
Front Pharmacol. 2018 Feb 28;9:149. doi: 10.3389/fphar.2018.00149. eCollection 2018.
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 P2Y receptors. qRT-PCR experiments showed that P2Y was the dominant nucleotide receptor expressed in mouse IEC. In addition, the P2Y ligand UDP induced expression and secretion of CXCL10. For the other studies, we took advantage of mice deficient in P2Y (). Similar expression levels of P2Y, P2Y, P2X2, P2X4, and A were detected in and WT IEC. Agonists of TLR3 (poly(I:C)), TLR4 (LPS), P2Y, and P2Y increased the expression and secretion of CXCL10 more prominently in IEC than in WT IEC. CXCL10 expression and secretion induced by poly(I:C) in both and WT IEC were inhibited by general P2 antagonists (suramin and Reactive-Blue-2), by apyrase, and by specific antagonists of P2Y, P2Y, P2Y (only in WT), and P2X4. Neither adenosine nor an A 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 IEC than in WT IEC. In conclusion, extracellular nucleotides regulate CXCL10 expression and secretion by IEC. In the absence of P2Y, these effects are modulated by other P2 receptors also present on IEC. These data suggest that the presence of P2Y regulates chemokine secretion and may also regulate IEC homeostasis.
在本研究中，我们研究了细胞外核苷酸在小鼠原代肠上皮细胞（IECs）趋化因子（KC、MIP-2、MCP-1和CXCL10）表达和分泌中的作用，重点关注P2Y受体。qRT-PCR实验表明，P2Y是在小鼠IEC中表达的主要核苷酸受体。此外，P2Y配体UDP诱导CXCL10的表达和分泌。对于其他研究，我们利用了P2Y缺陷小鼠。在P2Y缺陷小鼠和野生型（WT）IEC中检测到相似水平的P2Y、P2Y、P2X2、P2X4和A的表达。Toll样受体3（聚肌苷酸:聚胞苷酸（poly(I:C)））、Toll样受体4（脂多糖（LPS））、P2Y和P2Y的激动剂在P2Y缺陷小鼠IEC中比在WT IEC中更显著地增加CXCL10的表达和分泌。聚肌苷酸:聚胞苷酸在P2Y缺陷小鼠和WT IEC中诱导的CXCL10表达和分泌受到通用P2拮抗剂（苏拉明和活性蓝-2）、腺苷三磷酸双磷酸酶以及P2Y、P2Y、P2Y（仅在WT中）和P2X4的特异性拮抗剂的抑制。腺苷和A拮抗剂均对CXCL10的表达和分泌无影响。聚肌苷酸:聚胞苷酸处理的IEC的上清液诱导巨噬细胞趋化，这与分泌的CXCL10水平一致。最后，非核苷酸激动剂成纤维细胞生长因子2（FGF2）在P2Y缺陷小鼠IEC中也比在WT IEC中诱导更高水平的基质金属蛋白酶9（MMP9）mRNA表达。总之，细胞外核苷酸调节IEC的CXCL10表达和分泌。在缺乏P2Y的情况下，这些作用也受到IEC上存在的其他P2受体的调节。这些数据表明P2Y的存在调节趋化因子分泌，也可能调节IEC的内环境稳定。
