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Dual effect of the novel peptide antagonist K‐14585 on proteinase‐activated receptor‐2‐mediated signalling
Author(s) -
Goh Fui Goon,
Ng Pei Yuen,
Nilsson Mary,
Kanke Toru,
Plevin Robin
Publication year - 2009
Publication title -
british journal of pharmacology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.432
H-Index - 211
eISSN - 1476-5381
pISSN - 0007-1188
DOI - 10.1111/j.1476-5381.2009.00415.x
Subject(s) - phosphorylation , kinase , microbiology and biotechnology , p38 mitogen activated protein kinases , inositol phosphate , biology , chemistry , receptor , inositol , protein kinase a , biochemistry
Background and purpose: Here we have examined the effects of the novel peptide antagonist N‐[1‐(2,6‐dichlorophenyl)methyl]‐3‐(1‐pyrrolidinylmethyl) ‐1 H‐indol‐5‐yl]aminocarbonyl}‐glycinyl‐L‐lysinyl‐L‐phenylalanyl‐N‐benzhydrylamide (K‐14585) on proteinase‐activated receptor (PAR) 2 ‐mediated intracellular signalling events. Experimental approach: Using NCTC2544 cells expressing PAR 2 , we assessed the effects of K‐14585 on PAR 2 ‐mediated [ 3 H] inositol phosphate accumulation, MAP kinase activation, p65 NFκB phosphorylation and DNA binding and IL‐8 production. Key results: Pretreatment with K‐14585 (5 µM) inhibited [ 3 H] inositol phosphate levels stimulated by PAR 2 ‐activating peptide Ser‐Leu‐Ile‐Gly‐Lys‐Val (SLIGKV‐OH) in PAR 2 ‐expressing NCTC2544 cells. K‐14585 pretreatment did not influence PAR 2 ‐mediated extracellular regulated kinase activation but inhibited p38 MAP kinase phosphorylation. At a higher concentration (30 µM), K‐14585 alone stimulated p38 MAP kinase activation. These effects were replicated in EAhy926 cells, endogenously expressing PAR 2 , but not in parental or PAR 4 ‐expressing NCTC2544 cells, suggesting these effects were PAR 2 ‐dependent. SLIGKV‐mediated stimulation of p38 MAP kinase phosphorylation was substantially reduced by the G q/11 inhibitor YM‐254890, without affecting K‐14585‐mediated phosphorylation. Pretreatment with K‐14585 inhibited PAR 2 ‐mediated p65 NFκB phosphorylation and NFκB‐DNA binding. K‐14585 (30 µM) alone stimulated comparable NFκB reporter activity to SLIGKV‐OH. K‐14585 inhibited SLIGKV‐stimulated IL‐8 production, but given alone increased IL‐8. While SLIGKV‐induced IL‐8 formation was reduced by both SB203580 and YM‐254890, the response to K‐14585 was sensitive to SB203580 but not YM‐254890. Conclusions and implications: These data reveal that K‐14585 has a duality of action functioning both as an antagonist and agonist due to either partial agonist actions or possible agonist‐directed signalling. The data also suggest two modes of p38 MAP kinase activation emanating from PAR 2 , one G q/11 ‐dependent and the other G q/11 ‐independent.