Effects of NF-ĸB and MAPK inhibitors on P. gingivalis LPS
-induced MMP-3 mRNA (a) and protein (b) expression in HGFs. Cells were pretreated with IKK-2 inhibitor IV (NF-ĸB inhibitor), SB202190 (p38 MAPK inhibitor) and U1026 (ERK inhibitor) in serum free medium for 1 h, and then treated with P. gingivalis (Pg) LPS1690 (1 μg/ml) and E. coli LPS(1 μg/ml) for additional 12 h. Total RNA was harvested and MMP-3 mRNA levels were determined by real-time qPCR. Cell culture supernatants were collected and the protein expression level was measured by ELISA. The histogram shows quantitative representations of the MMP-3 mRNA levels of three independent experiments. Each value represents the mean ± SD. *Significant difference (p < 0.05) as compared with the controls. #Significant difference (p < 0.05) as compared with the cells treated with P. gingivalis LPS1690 or E. coli LPS alone.