IL-6 expression induced by adenosine A2b receptor stimulation in U373 MG cells depends on p38 mitogen activated kinase and protein kinase C

Neurochem Int. 2005 May;46(6):501-12. doi: 10.1016/j.neuint.2004.11.009.

Abstract

Adenosine binds to a class of G-protein coupled receptors, which are further distinguished as A(1), A(2a), A(2b) and A(3) adenosine receptors. As we have shown earlier, the stable adenosine analogue NECA (N6-(R)-phenylisopropyladenosine) stimulates IL-6 expression in the human astrocytoma cell line U373 MG via the A(2b) receptor. The mechanism by which NECA promotes astrocytic IL-6 expression has not been identified. By using various inhibitors of signal transduction, we found that p38 mitogen-activated protein kinases (MAPK) activation (inhibitor SB202190), but not extracellular signal-regulated kinase (ERK) (PD98059) and c-jun N-terminal kinase (JNK)(SP600125), is essential in the NECA-induced signalling cascade that leads to the increase in IL-6 synthesis in U373 MG cells. Results obtained with protein kinase C (PKC) inhibitors that have different substrate specificities, indicated that the PKC delta and epsilon isoforms are also involved in adenosine receptor A(2b) dependent upregulation of IL-6 expression. This is supported by the fact that NECA induced the activation of PKC delta and epsilon in U373 MG cells.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adenosine / metabolism*
  • Adenosine A2 Receptor Agonists
  • Astrocytoma / metabolism*
  • Cell Line, Tumor
  • Enzyme Inhibitors / pharmacology
  • Extracellular Signal-Regulated MAP Kinases / antagonists & inhibitors
  • Extracellular Signal-Regulated MAP Kinases / genetics
  • Extracellular Signal-Regulated MAP Kinases / metabolism
  • Humans
  • Interleukin-6 / metabolism*
  • JNK Mitogen-Activated Protein Kinases / antagonists & inhibitors
  • JNK Mitogen-Activated Protein Kinases / genetics
  • JNK Mitogen-Activated Protein Kinases / metabolism
  • Protein Kinase C / antagonists & inhibitors
  • Protein Kinase C / genetics
  • Protein Kinase C / metabolism*
  • Protein Kinase C-delta
  • Protein Kinase C-epsilon
  • RNA, Messenger / drug effects
  • RNA, Messenger / metabolism
  • Receptor, Adenosine A2B / metabolism*
  • Signal Transduction / drug effects
  • Signal Transduction / physiology*
  • Up-Regulation / drug effects
  • Up-Regulation / physiology
  • p38 Mitogen-Activated Protein Kinases / antagonists & inhibitors
  • p38 Mitogen-Activated Protein Kinases / genetics
  • p38 Mitogen-Activated Protein Kinases / metabolism*

Substances

  • Adenosine A2 Receptor Agonists
  • Enzyme Inhibitors
  • Interleukin-6
  • RNA, Messenger
  • Receptor, Adenosine A2B
  • PRKCD protein, human
  • PRKCE protein, human
  • Protein Kinase C
  • Protein Kinase C-delta
  • Protein Kinase C-epsilon
  • Extracellular Signal-Regulated MAP Kinases
  • JNK Mitogen-Activated Protein Kinases
  • p38 Mitogen-Activated Protein Kinases
  • Adenosine