RESUMEN
AIM:To examine the effects of thromboxane A 2 receptor ( TXA2 R) , the downstream product of cy-clooxygenase-2 (COX-2), on the proliferative ability and COX-2 expression in rheumatoid arthritis (RA) synovial cells. METHODS:The effects of TXA2 R antagonist SQ29548 and agonist U46619 on the proliferation of RA synovial cell line MH7A were detected by MTS cell proliferation assay , and their effects on COX-2 mRNA expression in MH7A cells were al-so examined by real-time PCR.In addition, the possible effect of U46619 on the proliferation of MH7A cells, when COX-2 was knocked down by siRNA , was determined by BrdU cell proliferation assay .RESULTS:SQ29548 inhibited the cell proliferation and the mRNA level of COX-2 while U46619 enhanced them.Moreover, U46619 reconstitute the proliferative ability of MH7A cells to some extent that inhibited by COX-2 siRNA.CONCLUSION: In RA synovial cells, TXA2R is able to control COX-2 expression, while it also mediates the effects of COX-2, suggesting that TXA2R might be an ideal candidate for RA treatment .