Thrombin inhibits Bim (Bcl-2-interacting mediator of cell death) expression and prevents serum-withdrawal-induced apoptosis via protease-activated receptor 1

Biochem J. 2003 Oct 1;375(Pt 1):99-109. doi: 10.1042/BJ20030346.


To investigate the role of thrombin in regulating apoptosis, we have used CCl39 cells, a fibroblast cell line in which thrombin-induced cell proliferation has been extensively studied. Withdrawal of serum from CCl39 cells resulted in a rapid apoptotic response that was completely prevented by the inclusion of thrombin. The protective effect of thrombin was reversed by pertussis toxin, suggesting that cell-survival signalling pathways are activated via a G(i) or G(o) heterotrimeric GTPase. Serum-withdrawal-induced death required de novo gene expression and was preceded by the rapid de novo expression of the pro-apoptotic 'BH3-only' protein Bim (Bcl-2-interacting mediator of cell death). Thrombin strongly inhibited the up-regulation of both Bim protein and Bim mRNA. The ability of thrombin to repress Bim expression, and to protect cells from apoptosis, was reversed by U0126, a MEK1/2 [MAPK (mitogen-activated protein kinase) or ERK (extracellular-signal-regulated kinase) 1/2] inhibitor, or LY294002, a phosphoinositide 3'-kinase (PI3K) inhibitor, suggesting that both the Raf-->MEK-->ERK1/2 and PI3K pathways co-operate to repress Bim and promote cell survival. A PAR1p (protease-activated receptor 1 agonist peptide) was also able to protect cells from serum-withdrawal-induced apoptosis, suggesting that thrombin acts via PAR1 to prevent apoptosis.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Apoptosis Regulatory Proteins
  • Apoptosis* / drug effects
  • Bcl-2-Like Protein 11
  • Carrier Proteins / genetics
  • Carrier Proteins / metabolism*
  • Cell Line
  • Cell Survival
  • Culture Media, Serum-Free
  • Etoposide / toxicity
  • Gene Expression Regulation
  • Membrane Proteins*
  • Mitogen-Activated Protein Kinases / metabolism
  • Pertussis Toxin / pharmacology
  • Phosphatidylinositol 3-Kinases / metabolism
  • Protein Biosynthesis
  • Protein Kinase C / metabolism
  • Proto-Oncogene Proteins*
  • Receptor, PAR-1
  • Receptors, Thrombin / metabolism*
  • Signal Transduction
  • Thrombin / antagonists & inhibitors
  • Thrombin / pharmacology*


  • Apoptosis Regulatory Proteins
  • Bcl-2-Like Protein 11
  • Carrier Proteins
  • Culture Media, Serum-Free
  • Membrane Proteins
  • Proto-Oncogene Proteins
  • Receptor, PAR-1
  • Receptors, Thrombin
  • Etoposide
  • Pertussis Toxin
  • Phosphatidylinositol 3-Kinases
  • Protein Kinase C
  • Mitogen-Activated Protein Kinases
  • Thrombin