ATP mediates NADPH oxidase/ROS generation and COX-2/PGE2 expression in A549 cells: role of P2 receptor-dependent STAT3 activation

PLoS One. 2013;8(1):e54125. doi: 10.1371/journal.pone.0054125. Epub 2013 Jan 11.

Abstract

Background: Up-regulation of cyclooxygenase (COX)-2 and its metabolite prostaglandin E(2) (PGE(2)) are frequently implicated in lung inflammation. Extracellular nucleotides, such as ATP have been shown to act via activation of P2 purinoceptors, leading to COX-2 expression in various inflammatory diseases, such as lung inflammation. However, the mechanisms underlying ATP-induced COX-2 expression and PGE(2) release remain unclear.

Principal findings: Here, we showed that ATPγS induced COX-2 expression in A549 cells revealed by western blot and real-time PCR. Pretreatment with the inhibitors of P2 receptor (PPADS and suramin), PKC (Gö6983, Gö6976, Ro318220, and Rottlerin), ROS (Edaravone), NADPH oxidase [diphenyleneiodonium chloride (DPI) and apocynin], Jak2 (AG490), and STAT3 [cucurbitacin E (CBE)] and transfection with siRNAs of PKCα, PKCι, PKCμ, p47(phox), Jak2, STAT3, and cPLA(2) markedly reduced ATPγS-induced COX-2 expression and PGE(2) production. In addition, pretreatment with the inhibitors of P2 receptor attenuated PKCs translocation from the cytosol to the membrane in response to ATPγS. Moreover, ATPγS-induced ROS generation and p47(phox) translocation was also reduced by pretreatment with the inhibitors of P2 receptor, PKC, and NADPH oxidase. On the other hand, ATPγS stimulated Jak2 and STAT3 activation which were inhibited by pretreatment with PPADS, suramin, Gö6983, Gö6976, Ro318220, GF109203X, Rottlerin, Edaravone, DPI, and apocynin in A549 cells.

Significance: Taken together, these results showed that ATPγS induced COX-2 expression and PGE(2) production via a P2 receptor/PKC/NADPH oxidase/ROS/Jak2/STAT3/cPLA(2) signaling pathway in A549 cells. Increased understanding of signal transduction mechanisms underlying COX-2 gene regulation will create opportunities for the development of anti-inflammation therapeutic strategies.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adenosine Triphosphate / analogs & derivatives
  • Adenosine Triphosphate / metabolism
  • Cell Line
  • Cell Line, Tumor
  • Cyclooxygenase 2* / genetics
  • Cyclooxygenase 2* / metabolism
  • Dinoprostone / biosynthesis*
  • Dinoprostone / metabolism
  • Gene Expression Regulation
  • Humans
  • Inflammation* / genetics
  • Inflammation* / metabolism
  • Inflammation* / physiopathology
  • Lung / pathology
  • NADPH Oxidases / genetics
  • NADPH Oxidases / metabolism
  • Reactive Oxygen Species / metabolism
  • Receptors, Purinergic P2* / genetics
  • Receptors, Purinergic P2* / metabolism
  • STAT3 Transcription Factor / genetics
  • STAT3 Transcription Factor / metabolism*
  • Signal Transduction
  • Transcriptional Activation

Substances

  • Reactive Oxygen Species
  • Receptors, Purinergic P2
  • STAT3 Transcription Factor
  • STAT3 protein, human
  • adenosine 5'-O-(3-thiotriphosphate)
  • Adenosine Triphosphate
  • Cyclooxygenase 2
  • PTGS2 protein, human
  • NADPH Oxidases
  • Dinoprostone

Grant support

This work was supported by NSC98-2321-B-182-004, NSC99-2321-B-182-003, NSC98-2314-B-182-021-MY3, and NSC98-2320-B-255-001-MY3 from National Science Council, Taiwan; EMRPD1A0831, EMRPD1A0841, EMRPD1B0311, and EMRPD1B0321 from Ministry of Education, Taiwan; and CMRPG391032, CMRPG381523, CMRPD170493, CMRPD180372, CMRPD1B0381, and CMRPG3B1091 from Chang Gung Medical Research Foundation, Taiwan. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.