Lysosomal exocytosis of ATP is coupled to P2Y2 receptor in marginal cells in the stria vascular in neonatal rats

P2Y2 and P2X4 Receptors Mediate Ca2+ Mobilization in DH82 Canine Macrophage Cells

“…This was consistent with previous studies that demonstrate coupling of P2Y 2 receptors to G q/11 and downstream signalling pathways in MDCK cells [49,65,71]. While 2-APB near completely inhibited Ca 2+ mobilisation, U-73122 only resulted in partial inhibition, although higher concentrations (>10 µM) have been shown to completely block P2Y 2 receptor-mediated Ca 2+ responses [72]. Notably, pre-incubation with P2Y 2 receptor antagonists resulted in approximately two-fold greater inhibition of UTP-induced Ca 2+ responses compared to ATP-induced responses, suggesting that ATP remained active at other receptors involved in mediating changes in intracellular Ca 2+ , such as P2X4 receptors, which are also relatively insensitive to suramin [73].…”

House Dust Mite Induces IL-33 Release From Human Nasal Epithelial Cells via P2Y Purinergic Signals and ERK/P38 MAPK Pathways.

“…However, recent studies reveal that allergen extracts including HDM, Artemisia vulgaris, Betula pendula and Altenaria alternata induce dose-dependent rapid release of ATP from HBECs, while which organelles ATP stores in and how ATP release from the cells are still unclear [28,29]. Our previous study revealed ATP induced the release of Ca 2+ from the ER Ca 2+ store of the marginal cells through the P2Y2-PLC-IP3 signaling pathway, and ATP releases from lysosomes through exocytosis [18].In the present research, it demonstrated that Quinacrine-labeled ATP was stored in lysosomes of human nasal epithelial cells which had an average 69.4% of co-localization with lysosomes (Figure .3). As reported, Quinacrine-labeled ATP appeared as puncta in large vesicles of olfactory epithelial cells [30].ATP functions through ATP-gated channels (P2X receptors) and G protein-coupled P2Y receptors, including P2X3,P2X4,P2X7,P2Y2,P2Y6,and P2Y11 receptors, all of which are expressed in the human nasal epithelial cells, which might play an important role in controlling the mucus and uid secretion [31].…”

“…As reported, Quinacrine-labeled ATP appeared as puncta in large vesicles of olfactory epithelial cells [30].ATP functions through ATP-gated channels (P2X receptors) and G protein-coupled P2Y receptors, including P2X3,P2X4,P2X7,P2Y2,P2Y6,and P2Y11 receptors, all of which are expressed in the human nasal epithelial cells, which might play an important role in controlling the mucus and uid secretion [31]. ATP is reported to evoke ER Ca 2+ release via P2Y-PLC-IP3 pathway and P2X ion channels in marginal cells, human monocytes and macrophage [18,32] In our study, pre-incubation with apyrase which hydrolyzed ATP into ADP e ciently suppressed HDM induced Ca 2+ responses. These results were consistent with those found in human keratinocytes which con rmed HDM induced acute extracellular accumulation of ATP activating P2Y 2 receptors [19].…”

“…Cells were plated on opaque 96-well plates (Coring, 3912, USA). An ATP bioluminescence assay kit (Promega, G7571, USA) was used to measure extracellular ATP release as described as previously [18].…”

“…In primary cultured bronchial epithelial cells, HDM promotes the release of intracellular endoplasmic reticulum Ca 2+ by activating ATP-dependent P2 purine receptors, thereby inducing cells to secrete CCL20 [17]. Our teams' previous studies have con rmed that ATP induces the release of Ca 2+ from the endoplasmic reticulum (ER) calcium store of the marginal cells through the P2Y2-PLC-IP3 signaling pathway, and ATP releases from lysosomes through exocytosis [18]. In keratinocytes, when stimulated by HDM, the cells quickly release a large amount of ATP, which rapidly induces the release of Ca2 + from the endoplasmic reticulum via activating extracellular P2Y purinergic receptor signaling, and enables activated keratinocytes to release IL-33 [19].…”