Agonists of proteinase-activated receptor 2 induce TNF-alpha secretion from astrocytoma cells

Cell Biochem Funct. 2002 Dec;20(4):339-45. doi: 10.1002/cbf.982.

Abstract

Proteinase-activated receptor 2 (PAR2) is cleaved and activated by trypsin or mast cell tryptase, and may play an important role in inflammation. We have investigated the potential of PAR2 agonists to modulate TNF-alpha secretion from human astrocytoma cell line CCF-STTG1. We found that CCF-STTG1 expresses PAR2 by RT-PCR and Western blot analysis. Agonists such as trypsin, the peptide SLIGKV-NH(2) (corresponding to the PAR2 tethered ligand), or mast cell tryptase directly signal to CCF-STTG1 to stimulate secretion of TNF-alpha but do not stimulate in the presence of soybean trypsin inhibitor (SBTI) or VKGILS-NH(2) (reverse peptide). The secretion of TNF-alpha by trypsin was significantly blocked by pretreatment with either 50 microM PD98059 or 1 microM SB203580. Furthermore, trypsin stimulated the activation of extracellular signal-regulated kinase (ERK) and p38 MAP kinase homologue in CCF-STTG1 without any detectable activation of c-Jun N-terminal kinase (JNK). These results show that trypsin may induce TNF-alpha secretion following activation of ERK and p38 via PAR2 in CCF-STTG1.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Astrocytoma / metabolism*
  • Blotting, Western
  • Calcium / metabolism
  • Central Nervous System / enzymology
  • Chymases
  • Cytokines / metabolism
  • Enzyme Activation
  • Enzyme Inhibitors / pharmacology
  • Enzyme-Linked Immunosorbent Assay
  • Flavonoids / pharmacology
  • Humans
  • Imidazoles / pharmacology
  • Mitogen-Activated Protein Kinases / metabolism
  • Peptides / chemistry
  • Peptides / pharmacology
  • Polymerase Chain Reaction
  • Protein Structure, Tertiary
  • Pyridines / pharmacology
  • RNA, Messenger / metabolism
  • Receptor, PAR-2
  • Receptors, Thrombin / agonists*
  • Reverse Transcriptase Polymerase Chain Reaction
  • Serine Endopeptidases / metabolism
  • Time Factors
  • Trypsin / pharmacology
  • Trypsin Inhibitors / pharmacology
  • Tumor Cells, Cultured
  • Tumor Necrosis Factor-alpha / metabolism*
  • p38 Mitogen-Activated Protein Kinases

Substances

  • Cytokines
  • Enzyme Inhibitors
  • Flavonoids
  • Imidazoles
  • Peptides
  • Pyridines
  • RNA, Messenger
  • Receptor, PAR-2
  • Receptors, Thrombin
  • Trypsin Inhibitors
  • Tumor Necrosis Factor-alpha
  • Mitogen-Activated Protein Kinases
  • p38 Mitogen-Activated Protein Kinases
  • Serine Endopeptidases
  • Chymases
  • Trypsin
  • SB 203580
  • 2-(2-amino-3-methoxyphenyl)-4H-1-benzopyran-4-one
  • Calcium