Extracellular ATP induces cytokine expression and apoptosis through P2X7 receptor in murine mast cells.
Extracellular ATP and other nucleotides act through specific cell surface receptors and regulate a wide variety of cellular responses in many cell types and tissues. In this study, we demonstrate that murine mast cells express several P2Y and P2X receptor subtypes including P2X(7), and describe functional responses of these cells to extracellular ATP. Stimulation of bone marrow-derived mast cells (BMMC), as well as MC/9 and P815 mast cell lines with millimolar concentrations of ATP, resulted in Ca(2+) influx across the cellular membrane and cell permeabilization. Moreover, brief exposures to ATP were sufficient to induce apoptosis in BMMCs, MC/9, and P815 cells which involved activation of caspase-3 and -8. However, in the time period between commitment to apoptosis and actual cell death, ATP triggered rapid but transient phosphorylation of multiple signaling molecules in BMMCs and MC/9 cells, including ERK, Jak2, and STAT6. In addition, ATP stimulation enhanced the expression of several proinflammatory cytokines, such as IL-4, IL-6, IL-13, and TNF-alpha. The effects of ATP were mimicked by submillimolar concentrations of 3-O-(4'-benzoyl)-benzoyl-benzoyl-ATP, and were inhibited by pretreatment of mast cells with a selective blocker of human and mouse P2X(7) receptor, 1[N,O-bis(5-isoquinolinesulphonyl)-N-methyl-l-tyrosyl]-4-phenylpiperazine, as well as oxidized ATP. The nucleotide selectivity and pharmacological profile data support the role for P2X(7) receptor as the mediator of the ATP-induced responses. Given the importance of mast cells in diverse pathological conditions, the ability of extracellular ATP to induce the P2X(7)-mediated apoptosis in these cells may facilitate the development of new strategies to modulate mast cell activities.
Bulanova
Elena
E
Department of Immunology and Cell Biology, Research Center Borstel, Borstel, Germany. ebulanova@fz-borstel.de <ebulanova@fz-borstel.de>
Budagian
Vadim
V
Orinska
Zane
Z
Hein
Martina
M
Petersen
Frank
F
Thon
Lutz
L
Adam
Dieter
D
Bulfone-Paus
Silvia
S
D000255:Adenosine Triphosphate / Q000494:pharmacology*; D000818:Animals; D017209:Apoptosis / Q000187:drug effects*; D001854:Bone Marrow Cells; D020013:Calcium Signaling; D002478:Cells, Cultured; D016207:Cytokines / Q000235:genetics*; D005786:Gene Expression Regulation / Q000187:drug effects; D008407:Mast Cells / Q000187:drug effects*; D051379:Mice; D008810:Mice, Inbred C57BL; D010766:Phosphorylation; D018048:Receptors, Purinergic P2 / Q000502:physiology*; D058486:Receptors, Purinergic P2X7; D015398:Signal Transduction
D016207:Cytokines; C546468:P2RX7 protein, human; C546469:P2rx7 protein, mouse; D018048:Receptors, Purinergic P2; D058486:Receptors, Purinergic P2X7; D000255:Adenosine Triphosphate