Expression of functional type 1 protease-activated thrombin receptors by mouse primary palatal mesenchymal cells in vitro.
Development of the primary palate involves a series of processes including cell growth, differentiation, and morphogenesis. To study the molecular and cellular processes during mouse primary palatogenesis, mesenchymal cells were isolated from the primary palate of BALB/cBy embryos (day-11, hour 20). Most of the primary palatal mesenchymal (PPM) cells were morphologically similar to fibroblasts. The population doubling time was about 36 h. At concentrations of 5 and 10 unit/ml, alpha-thrombin significantly stimulated the proliferation of these palatal cells by 2- to 2. 4-fold compared to untreated controls over a 72 hour incubation period. Reverse transcriptase-polymerase chain reaction using primers based on the mouse type 1 protease-activated thrombin receptor (PAR1) detected PAR1 mRNA in the PPM cells, the authenticity of which was confirmed by partial DNA sequencing. Blocking of the alpha-thrombin proteolytic site with the highly specific inhibitor D-phenylalanyl-prolyl-arginyl chloromethyl ketone significantly suppressed the mitogenic effect of thrombin on the PPM cells by 71%. These results suggest that PAR1 is present on PPM cells in the mouse embryo and that serine protease activity is important for the receptor activation.
Wang
K Y
KY
School of Dentistry, College of Medicine, National Taiwan University, 1, Chang-Te Street, 10016, Taipei, Taiwan.
Chang
F H
FH
Jeng
J H
JH
Hou
L T
LT
Chen
K C
KC
Kuo
M Y
MY
D000590:Amino Acid Chloromethyl Ketones / Q000494:pharmacology; D000818:Animals; D000991:Antithrombins / Q000494:pharmacology; D002454:Cell Differentiation / Q000502:physiology; D002455:Cell Division / Q000187:drug effects / Q000502:physiology; D046508:Culture Techniques; D005786:Gene Expression Regulation; D008648:Mesoderm / Q000166:cytology* / Q000187:drug effects; D051379:Mice; D008807:Mice, Inbred BALB C; D008815:Mice, Inbred Strains; D008934:Mitogens / Q000037:antagonists & inhibitors; D009024:Morphogenesis / Q000502:physiology; D010159:Palate / Q000166:cytology / Q000187:drug effects / Q000196:embryology*; D012333:RNA, Messenger / Q000235:genetics; D044463:Receptor, PAR-1; D018179:Receptors, Thrombin / Q000037:antagonists & inhibitors / Q000235:genetics*; D012697:Serine Endopeptidases / Q000502:physiology; D015842:Serine Proteinase Inhibitors / Q000494:pharmacology; D013917:Thrombin / Q000037:antagonists & inhibitors / Q000235:genetics*; D013997:Time Factors
D000590:Amino Acid Chloromethyl Ketones; D000991:Antithrombins; D008934:Mitogens; D012333:RNA, Messenger; D044463:Receptor, PAR-1; D018179:Receptors, Thrombin; D015842:Serine Proteinase Inhibitors; D012697:Serine Endopeptidases; D013917:Thrombin; C040308:phenylalanyl-prolyl-arginine-chloromethyl ketone