【摘要】 目的　研究地塞米松和吲哚美辛对U937细胞中基质金属蛋白酶 9(MMP 9)活性的影响及抗炎作用机理。方法　明胶酶谱法测定MMP 9的活性 ;Westernblot法测定细胞培养上清液中MMP 9蛋白 ;RT PCR法测定MMP 9mRNA的表达。结果　地塞米松和吲哚美辛可显著抑制PMA诱导的U937细胞培养上清液中MMP 9的活性 ,且抑制强度随浓度的增大而增加 ;地塞米松和吲哚美辛可显著抑制PMA诱导的的U937细胞MMP 9蛋白分泌及mRNA表达 ,且变化趋势与活性变化一致。结论　对MMP 9活性的抑制作用可能是地塞米松和吲哚美辛抗炎作用的机理之一。更多还原

【Abstract】 Aim To study the inhibitory effect of dexamethasone and indomethacin on matrix metalloproteinase-9 (MMP-9) and investigate their mechanism of MMP-9 inhibition on the level of protein and mRNA. Methods U937 cells were cultured in RPMI 1640 medium with 10% fetal calf serum (FCS). After U937 cells were exposed to 1×10 -8 mol·L -1 phorbol 12-myristate 13-acetate (PMA) for 24 hours without FCS, the activity of MMP-9 in the supernatant was analyzed by gelatin zymography. The MMP-9 protein secreted from U937 in serum-free conditional media was detected by Western blot using special polyclonal antibodies. The mRNA expression of MMP-9 was investigated by RT-PCR. Results Gelatin zymography showed that MMP-9 activity in U937 cells supernatant increased significantly after exposed to 1×10 -8 mol·L -1 PMA for 24 hours without FCS. Dexamethasone at 1×10 -5 , 1×10 -7 , 1×10 -9 mol·L -1 and indomethacin at 1×10 -5 , 1×10 -6 , 1×10 -7 mol·L -1 can inhibit this increase. Western blot showed that MMP-9 secretion from U937 cells in serum-free conditional media was increased under the same stimulating condition, Dexamethasone and indomethacin can inhibit MMP-9 secretion in U937 cells stimulated by 1×10 -8 mol·L -1 PMA and the inhibitory effect was increased as their concentration increased. RT-PCR showed that MMP-9 mRNA expression of U937 cells was also inhibited and the inhibitory effect was increased as their concentration increased. Conclusion Inhibition of MMP-9 activity may be one of the anti-inflammatory mechanisms of dexamethasone and indomethacin; the inhibition of MMP-9 activity is coherent with the inhibition of MMP-9 secretion and mRNA expression.更多还原