Thrombin regulates interleukin-6 synthesis through phosphatidylcholine hydrolysis by phospholipase D in osteoblasts

Arch Biochem Biophys. 1997 Sep 1;345(1):10-5. doi: 10.1006/abbi.1997.0232.


We previously reported that thrombin stimulates Ca2+ influx and activates phosphatidylcholine-hydrolyzing phospholipase D in osteoblast-like MC3T3-E1 cells. In this study, we investigated the effect of thrombin on interleukin-6 (IL-6) synthesis in these cells. Thrombin stimulated IL-6 synthesis dose-dependently in the range between 0.01 and 1 U/ml. The depletion of extracellular Ca2+ by EGTA suppressed the thrombin-induced IL-6 synthesis. TMB-8, an inhibitor of intracellular Ca2+ mobilization, also inhibited the IL-6 synthesis by thrombin. Propranolol, a phosphatidic acid phosphohydrolase inhibitor, enhanced the IL-6 synthesis by thrombin. Calphostin C, a highly potent and specific inhibitor for protein kinase C, significantly amplified the IL-6 synthesis by thrombin. The thrombin-induced IL-6 synthesis was enhanced in PKC down-regulated MC3T3-E1 cells. These results strongly suggest that thrombin stimulates IL-6 synthesis, which depends on intracellular Ca2+ mobilization mainly from extracellular space in osteoblasts, and that the IL-6 synthesis by thrombin is regulated due to thrombin-activated protein kinase C through phosphatidylcholine-hydrolyzing phospholipase D.

MeSH terms

  • Animals
  • Calcium / metabolism
  • Calcium Channel Blockers / pharmacology
  • Cell Line
  • Egtazic Acid / pharmacology
  • Enzyme Inhibitors / pharmacology
  • Ethanol / pharmacology
  • Gallic Acid / analogs & derivatives
  • Gallic Acid / pharmacology
  • Interleukin-6 / biosynthesis*
  • Mice
  • Naphthalenes / pharmacology
  • Osteoblasts / drug effects
  • Osteoblasts / metabolism*
  • Phosphatidate Phosphatase / antagonists & inhibitors
  • Phosphatidylcholines / metabolism*
  • Phospholipase D / metabolism*
  • Propranolol / pharmacology
  • Protein Kinase C / antagonists & inhibitors
  • Thrombin / administration & dosage
  • Thrombin / pharmacology*


  • Calcium Channel Blockers
  • Enzyme Inhibitors
  • Interleukin-6
  • Naphthalenes
  • Phosphatidylcholines
  • Ethanol
  • Egtazic Acid
  • 8-(N,N-diethylamino)octyl-3,4,5-trimethoxybenzoate
  • Gallic Acid
  • Propranolol
  • Protein Kinase C
  • Phosphatidate Phosphatase
  • Phospholipase D
  • Thrombin
  • calphostin C
  • Calcium