9-cisRA inhibits expression of MMP-9 in THP-1 human monocytes induced by PMA

AIM To investigate the effect of 9-cisRA(9-cis-Retinoic Acid),a specific agonist of retinoid X receptors(RXRs),on the expression and activities of matrix metalloproteinase-9(MMP-9) in THP-1 human monocytes induced by PMA.METHODS Human monocytic cell lines THP-1 were cultured and induced to macrophages by PMA treatment.The differentiated monocytes were then cultured in the medium of PMA at different concentrations treated with 9-cisRA(100 nmol/L) and the gene expression,protein expression and activity of MMP-9 were detected by Realtime-PCR,Western blotting and Gelatin Zymography respectively.RESULTS After 24 h treatment of 100 nmol/L 9-cisRA,the mRNA level of MMP-9 in THP-1 cells induced by PMA at different concentrations(10,20 and 40 nmol/L) decreased by 28%,60%,88%(P0.01) respectively,while the protein level and activity of MMP-9 also dropped significantly.CONCLUSION 9-cisRA,a specific agonist of RXRs,effectively inhibits the mRNA,protein level and activity of MMP-9 in THP-1 cells induced by PMA.