Department of Bioscience and Laboratory Medicine, Hirosaki University Graduate School of Health Sciences, Aomori, Japan; Research Center for Biomedical Sciences, Hirosaki University Graduate School of Health Sciences, Aomori, Japan.
Department of Bioscience and Laboratory Medicine, Hirosaki University Graduate School of Health Sciences, Aomori, Japan; Research Center for Biomedical Sciences, Hirosaki University Graduate School of Health Sciences, Aomori, Japan.
Allergol Int. 2017 Oct;66(4):574-580. doi: 10.1016/j.alit.2017.02.014. Epub 2017 Mar 17.
P2Y purinergic receptors (P2YR) are G protein-coupled receptors that are stimulated by extracellular nucleotides. They mediate cellular effects by regulating cAMP production, protein kinase C activation, inositol trisphosphate generation, and Ca release from intracellular stores. The P2Y6 receptor of this family is selectively stimulated by UDP, and selectively inhibited by MRS2578. In the present study, we examined the effect of UDP/P2Y6 receptor signaling on IgE-dependent degranulation in human basophils.
Basophils were purified from human peripheral blood. The mRNA expression of genes encoding P2YR and ecto-nucleoside triphosphate diphosphohydrolase (ENTPDase) was measured by RT-PCR. Intracellular Ca influx via UDP/P2Y6 receptor signaling in basophils was detected using a calcium probe. The effect of UDP/P2Y6 receptor signaling on IgE-dependent degranulation in basophils was confirmed by measuring CD63 expression by flow cytometry. Autocrine secretion of nucleotides was detected by HPLC analysis.
We showed that purified basophils express P2Y6 mRNA and that UDP increased intracellular Ca, which was reduced by MRS2578 treatment. UDP promoted IgE-dependent degranulation. Furthermore, MRS2578 inhibited IgE-dependent degranulation in basophils. HPLC analysis indicated that basophils spontaneously secrete UTP. In addition, basophils expressed the extracellular nucleotide hydrolases ENTPDase2, ENTPDase3, and ENTPDase8.
This study showed that UDP/P2Y6 receptor signaling is involved in the regulation of IgE-dependent degranulation in basophils, which might stimulate the P2Y6 receptor via the autocrine secretion of UTP. Thus, this receptor represents a potential target to regulate IgE-dependent degranulation in basophils during allergic diseases.
P2Y 嘌呤能受体（P2YR）是受细胞外核苷酸刺激的 G 蛋白偶联受体。它们通过调节 cAMP 产生、蛋白激酶 C 激活、三磷酸肌醇生成和细胞内储存的 Ca 释放来介导细胞效应。该家族的 P2Y6 受体被 UDP 选择性刺激，并被 MRS2578 选择性抑制。在本研究中，我们研究了 UDP/P2Y6 受体信号对人嗜碱性粒细胞中 IgE 依赖性脱颗粒的影响。
从人外周血中纯化嗜碱性粒细胞。通过 RT-PCR 测量编码 P2YR 和外核苷酸三磷酸二磷酸水解酶（ENTPDase）的基因的 mRNA 表达。通过钙探针检测 UDP/P2Y6 受体信号转导在嗜碱性粒细胞中的细胞内 Ca 内流。通过流式细胞术测量 CD63 表达来确认 UDP/P2Y6 受体信号对嗜碱性粒细胞中 IgE 依赖性脱颗粒的影响。通过 HPLC 分析检测核苷酸的自分泌分泌。
我们表明，纯化的嗜碱性粒细胞表达 P2Y6 mRNA，UDP 增加细胞内 Ca，而 MRS2578 处理则降低了细胞内 Ca。UDP 促进 IgE 依赖性脱颗粒。此外，MRS2578 抑制嗜碱性粒细胞中 IgE 依赖性脱颗粒。HPLC 分析表明嗜碱性粒细胞自发分泌 UTP。此外，嗜碱性粒细胞表达细胞外核苷酸水解酶 ENTPDase2、ENTPDase3 和 ENTPDase8。
本研究表明，UDP/P2Y6 受体信号参与调节嗜碱性粒细胞中 IgE 依赖性脱颗粒，这可能通过 UTP 的自分泌刺激 P2Y6 受体。因此，该受体可能成为调节过敏疾病期间嗜碱性粒细胞中 IgE 依赖性脱颗粒的潜在靶标。
