Synergistic Cytokine Production by ATP and PGE2 via P2X4 and EP3 Receptors in Mouse Bone-Marrow-Derived Mast Cells.

Kosuke Obayashi,Toshiyashu Imai,Isao Matsuoka,Masa-Aki Ito,Tetsuya Mori,Kimiko Yamamoto,Kazuki Yoshida

doi:10.3390/cells11040616

Kosuke Obayashi, Toshiyashu Imai + Show 5 more

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https://doi.org/10.3390/cells11040616

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Abstract

ATP is an important intercellular messenger in the extracellular space. In mast cells (MCs), ATP stimulates the ionotropic P2X4 receptor (P2X4R), resulting in enhanced degranulation and exacerbation of acute allergic reactions. In this study, we investigate whether ATP regulates inflammatory cytokine production in MCs. Gene expression was analyzed by quantitative RT-PCR, and cytokine production was measured using ELISA. The stimulation of mouse bone-marrow-derived MCs (BMMCs) with ATP alone had little effect on cytokine secretion. However, the co-stimulation with prostaglandin (PG) E2 resulted in a marked increase in the secretion of various cytokines, such as tumor necrosis factor-α, interleukin (IL)-6, and IL-13, accompanied by an increase in their mRNA levels. The effects of ATP were inhibited by P2X4R antagonists and diminished in BMMCs derived from P2X4R-deficient mice, suggesting that P2X4R mediated the reaction. The effects of PGE2 were mimicked by an EP3 receptor (EP3R) agonist and blocked by an EP3R antagonist. The synergistic cytokine mRNA elevations induced by ATP and PGE2 were blocked by nuclear factor-κB and Ca2+-calcineurin signaling inhibitors. Altogether, these results suggest that combining P2X4R and EP3R signaling enhances acute degranulation and the subsequent cytokine secretion, exacerbating allergic inflammation.

Highlights

Adenosine triphosphate (ATP), an important intracellular energy source constantly supplied by cell metabolism under cellular respiration, is present in high concentrations in the cytosol
We investigate whether extracellular ATP affects the production of cytokines by antigen and non-antigen stimulation using bone-marrow-derived MCs (BMMCs)
We examined the effects of ATP on PGE2 or antigen dinitrophenyl human serum albumin (DNP-HSA)-induced mRNA

Summary

Introduction

Adenosine triphosphate (ATP), an important intracellular energy source constantly supplied by cell metabolism under cellular respiration, is present in high concentrations in the cytosol. Cells release ATP into the extracellular space as an intercellular mediator to regulate various physiological functions [1]. Extracellular ATP accumulation is recognized by various receptors called P2 receptors. Seven subtypes of ionotropic P2X receptors (P2X1-7) recognize ATP exclusively and open non-selective cation channels [2]. Eight subtypes of G protein-conjugated P2Y receptors have been identified in humans, including P2Y1 , Y2 , Y4 , Y6 , and Y11–14 receptors, and the ligands are ATP and ADP and uridine nucleotides, such as UTP, UDP, and UDP-glucose [3]. Receptor activation is transmitted into cells by the G protein-dependent signaling [3]. ATP is involved in regulating physiological functions as a spatially and temporally diverse intercellular transmitter

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