Augmentation of ADAMTS9 gene expression by IL-1β is reversed by NFκB and MAPK inhibitors, but not PI3 kinase inhibitors.

The pathways involved in the regulation of a disintegrin and metalloproteinase with thrombospondin motifs 9 (ADAMTS9) expression have not yet been elucidated. Therefore, the aim of this study was to investigate the involvement of nuclear factor-κB (NF-κB), mitogen activated protein kinases (MAPK) and Phosphatidylinositol 3-kinase (PI3 kinase) in ADAMTS9 gene regulation, with special focus on the involvement of NF-κB in IL-1β-induced ADAMTS9 expression. The OUMS-27 chondrosarcoma cells were exposed to IL-1β. They were pretreated with 20 μM PD98059 (specific inhibitor of p44/42 kinase), 10 μM SB203580 (specific inhibitor of p38 kinase), 20 μM SB600125 (MAPK inhibitor), and 1 μM Wortmannin and 10 μM LY294002 (specific inhibitors of PI3 kinase) for 30 min and subsequently incubated with IL-1β. For the effects of NF-κB and IκB inhibitors, cells were pretreated with curcumin or BAY117085 for 30 min and subsequently incubated with IL-1β. BAY117085 and different concentrations of curcumin were applied to the cells just after the first experiment to determine their concentration effect on ADAMTS9 gene expression. After total RNA was extracted, they were reversely transcribed with random primers and then real-time polymerase chain reaction (PCR) was performed on cDNA samples. There was a significant difference between control and stimulated cells in terms of ADAMTS9/β-actin ratio. Wortmannin and LY294002 did not have any repressive effect on the OUMS-27 whereas SB203580 and SP600125 were found to decrease the expression of ADAMTS9 gene. BAY 117085 and curcumin, which are two NF-κB inhibitors, led to a decrease in the ratio of ADAMTS9/β-actin. As a conclusion, the pathways MAPK and NF-κB were thought to be responsible pathways for the induction of ADAMTS9 gene.