Thrombin Induces COX-2 and PGE₂ Expression via PAR1/PKCalpha/MAPK-Dependent NF-kappaB Activation in Human Tracheal Smooth Muscle Cells

Figure 2

Thrombin enhances COX-2 expression via G-coupled receptor Gq and Gi/o subunit. (a) Cells were pretreated with GPA2 or GPA2A for 1 h and then incubated with thrombin for 6 h. The levels of COX-2 protein were determined. (b) Cells were pretreated with GPA2 (1 μM) or GPA2A (1 μM) for 1 h, and then incubated with thrombin for 4 h. The mRNA levels and promoter activity of COX-2 were determined. (c) Cells were transfected with scrambled, Gqα, or Giα siRNA and then incubated with thrombin for 6 h. The levels of Gqα, or Giα, and COX-2 protein were determined. (d) The media saved from (c) were used to determine the levels of PGE₂ generation. Data are expressed as of three independent experiments. ^#, as compared with the control or pretreatment with inhibitor indicated in the figure.

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