Differential DNA synthesis in response to activation of protease-activated receptors on cultured guinea-pig tracheal smooth muscle cells.
Both thrombin and tryptase have been shown to induce smooth muscle cell proliferation in vitro. We have used cultured primary guinea-pig tracheal smooth muscle in order to define pharmacologically the receptors involved in this effect. Tryptase, a protease-activated receptor (PAR)-2 agonist, induced DNA synthesis up to the second passage of the cells, thereafter the response waned. In contrast, thrombin, a PAR-1 agonist, and the PAR-1 activating peptide (SFLLRN) induced DNA synthesis starting from the third passage only. Thrombin and tryptase responses were dose-dependently inhibited by leupeptin. The selective PAR-2 activating peptide (SLIGRL-NH(2)) was unable to induce DNA synthesis in cells from passages 1 to 6. In agreement with the functional data, mRNA expression for PAR-1 was increased in cells in later passages. In contradiction with the functional data, however, equal mRNA expression for PAR-2 was found in all passages. These results suggest that thrombin induces guinea-pig tracheal smooth muscle DNA synthesis through activation of PAR-1. However, the differential effect of tryptase and SLIGRL-NH(2) suggests that tryptase might exert some of its effect via a non-PAR-2 receptor.
Corteling
Randolph
R
Novartis Respiratory Research Centre, Wimblehurst Road, Horsham, RH12 5AB, UK.
Bonneau
Olivier
O
Ferretti
Stephane
S
Ferretti
Mireille
M
Trifilieff
Alexandre
A
D000199:Actins / Q000494:pharmacology; D000818:Animals; D002455:Cell Division / Q000187:drug effects / Q000502:physiology; D002478:Cells, Cultured; D004247:DNA / Q000096:biosynthesis*; D006168:Guinea Pigs; D006801:Humans; D007976:Leupeptins / Q000494:pharmacology; D009130:Muscle, Smooth / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D010455:Peptides / Q000494:pharmacology; D011480:Protease Inhibitors / Q000494:pharmacology; D012333:RNA, Messenger / Q000378:metabolism; D044463:Receptor, PAR-1 / Q000819:agonists* / Q000235:genetics / Q000378:metabolism; D044464:Receptor, PAR-2 / Q000819:agonists* / Q000235:genetics / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012697:Serine Endopeptidases / Q000494:pharmacology; D013917:Thrombin / Q000494:pharmacology; D013936:Thymidine / Q000378:metabolism; D014132:Trachea / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D053802:Tryptases
D000199:Actins; D007976:Leupeptins; D010455:Peptides; D011480:Protease Inhibitors; D012333:RNA, Messenger; D044463:Receptor, PAR-1; D044464:Receptor, PAR-2; C016977:amastatin; D004247:DNA; D012697:Serine Endopeptidases; D013917:Thrombin; D053802:Tryptases; C032854:leupeptin; D013936:Thymidine