Agonists of proteinase-activated receptor 2 induce TNF-alpha secretion from astrocytoma cells.
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.
Kim
Mi-Sun
MS
Department of Oriental Pharmacy, College of Pharmacy, Wonkwang University, Iksan, Cheonbuk 570-749, South Korea.
Jo
Hyun
H
Um
Jae-Young
JY
Yi
Jin-Mu
JM
Kim
Dae-Ki
DK
Choi
Suck-Chei
SC
Kim
Tae-Hyun
TH
Nah
Yong-Ho
YH
Kim
Hyung-Min
HM
Lee
Young-Mi
YM
D001254:Astrocytoma / Q000378:metabolism*; D015153:Blotting, Western; D002118:Calcium / Q000378:metabolism; D002490:Central Nervous System / Q000201:enzymology; D053818:Chymases; D016207:Cytokines / Q000378:metabolism; D004789:Enzyme Activation; D004791:Enzyme Inhibitors / Q000494:pharmacology; D004797:Enzyme-Linked Immunosorbent Assay; D005419:Flavonoids / Q000494:pharmacology; D006801:Humans; D007093:Imidazoles / Q000494:pharmacology; D020928:Mitogen-Activated Protein Kinases / Q000378:metabolism; D010455:Peptides / Q000737:chemistry / Q000494:pharmacology; D016133:Polymerase Chain Reaction; D017434:Protein Structure, Tertiary; D011725:Pyridines / Q000494:pharmacology; D012333:RNA, Messenger / Q000378:metabolism; D044464:Receptor, PAR-2; D018179:Receptors, Thrombin / Q000819:agonists*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012697:Serine Endopeptidases / Q000378:metabolism; D013997:Time Factors; D014357:Trypsin / Q000494:pharmacology; D014361:Trypsin Inhibitors / Q000494:pharmacology; D014407:Tumor Cells, Cultured; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism*; D048051:p38 Mitogen-Activated Protein Kinases
D016207:Cytokines; D004791:Enzyme Inhibitors; D005419:Flavonoids; D007093:Imidazoles; D010455:Peptides; D011725:Pyridines; D012333:RNA, Messenger; D044464:Receptor, PAR-2; D018179:Receptors, Thrombin; D014361:Trypsin Inhibitors; D014409:Tumor Necrosis Factor-alpha; D020928:Mitogen-Activated Protein Kinases; D048051:p38 Mitogen-Activated Protein Kinases; D012697:Serine Endopeptidases; D053818:Chymases; D014357:Trypsin; C093642:SB 203580; C093973:2-(2-amino-3-methoxyphenyl)-4H-1-benzopyran-4-one; D002118:Calcium