Fig 1.
Trypase via PAR2 increases COX2 levels and stimulates PG synthesis and fibroblast proliferation. (a) Example of an RT-PCR analysis, showing rapid up-regulation of COX2 mRNA in HFFF2 cells after treatment with tryptase. mIU, milliunits. (b) Immunoblot depicting increased COX2 protein levels in HFFF2 cells from 10 to 1,440 min after treatment with tryptase (2.5 μg of total protein per lane). (c) Immunoblot showing that the PAR2 agonist peptide SLIGKV also increases COX2 protein levels (15 μg of total protein per lane). (d) HMCs (HMC-1) contain tryptase (see Western blot, Left, 15 μg of total protein). Dot blot shows that HMC-1 cells contain tryptase and secrete tryptase into the culture medium (Right, basal or HMC-1-conditioned medium, collected from 5 × 106 cells after 24 h of incubation, were loaded). (e and f) Tryptase increases PGF2α (e) and 15d-PGJ2 (f) production in HFFF2s. The data represent means ± SEMs of values obtained after 1 and 3 h of treatment with tryptase (n = 4 per treatment). *, P < 0.05 vs. the corresponding control group. (g) Tryptase stimulates fibroblast proliferation via PAR2, COX2 up-regulation, and PGJ2 production. Meloxicam (a COX2 antagonist) inhibits the stimulatory action of conditioned medium collected from HMCs (HMC-1), recombinant human tryptase, and the PAR2 agonist peptide SLIGKV on HFFF2 proliferation after 24 h of incubation. This figure shows results obtained from one of three experiments that yielded comparable results. The results shown are means + SEMs of n = 8–12 replicate wells per treatment. *, P < 0.05 vs. the corresponding control group.