Effect Of DQ12on MMP-9mRNA Expression And Enzyme Activity Of Differentiated THP-1Cells And The Intervention Study Of Relaxin

ObjectiveTo study the impact of DQ12on MMP-9mRNA expression and enzyme activityin phorbol esters(PMA)-induced THP-1cells and the intervention effect of relaxin.MethodsTHP-1cells were grown in RPMI-1640medium supplemented withheat-inactivated foetal calf serum (FCS). when they were in the exponential growthphase, and were inoculated at a density of8×105cells in6well plates. THP-1cellswere stimμl ated with10ng/ml PMA for24h and then cul tured with FCS-free mediumfor3h. Next, THP-1cells were randomly divided into three groups: DQ12group,DQ12+R group and the control group. THP-1cells in the control group, DQ12groupand DQ12+R group were respectively cμl tured with FCS-free medium, FCS-freemedium containing100ug/ml DQ12and FCS-free medium containing100ug/ml DQ12and10ng/ml relaxin. THP-1cells culture supernatant were collected and THP-1cellswere harvested at1,3,12,24h. RNA was extracted from the THP-1cells and qRT-PCRwas performed for MMP-9mRNA quantitation; MMP-9activity was assayed usinggelatin zymography.ResultsMMP-9mRNA expression in THP-1cells began to increase after12h of DQ12exposure, and maintained at a higher level after24h exposure; Compared to thecontrol group, enhanced levels of MMP-9activity of THP-1cells in DQ12groupwere observed at1,3,12,24h. Compared to the DQ12group MMP-9mRNA expression was reduced after3、12、24h of relaxin exposure; however there is no obvious chang on MMP-9activitybetween the two groups.ConclusionDQ12increased MMP-9mRNA expression and activity in PMA-differentiatedTHP-1cells, and increased MMP-9expression could be inhibited by relaxin, butrelaxin have no influence on increased MMP-9activity. Our findings suggest relaxincould inhibit the development of silica induced lung fibrosis by affecting matrixmetalloproteinase-9expression in macrophages.