抄録
Background
Matrix metalloproteinases (MMPs) and pro-inflammatory cytokines overproduced by activated human monocytes/macrophages that involve in the progression of inflammatory diseases. In this study, we evaluated the functions and mechanisms of a novel compound-61-1 (C61-1) isolated from the red alga-derived fungus Chondrostereum sp. NTOU4196 on pro-inflammatory mediators produced from lipopolysaccharide (LPS) stimulated human monocytic THP-1 cells.
Methods
THP-1 cells (1 x 10^6 cells/mL) were pretreated with C61-1(5, 10 and 20 microM) or vehicle (DMSO) for 15 min and were subsequently stimulated with LPS (50 ng/ml) for 24 h, followed by collection of the supernatants. MMP-mediated gelatinolysis was determined by gelatin zymography. The levels of interleukin (IL)-1 beta and IL-6 secretases by THP-1 cells were quantified using the ELISA. The cytotoxic effects of C61-1 against the THP-1 cells were in relation to vehicle-treated controls that were detected by the MTT assay. For the signaling studies, THP-1 cells pretreated with C61-1(5, 10 and 20 microM) or vehicle for 15 min and were subsequently stimulated with LPS (50 ng/ml) for different time periods and were harvested and lysed. Stat3 (Tyr705) phosphorylation, ERK phosphorylation, IKK-alpha/beta phosphorylation and IkappaB-alpha degradation was evaluated by immunoblotting.
Results
C61-1 suppressed LPS-activated MMP-9-mediated gelatinolysis and MMP-9 protein expression in concentration-dependent manner. Furthermore, C61-1 strongly attenuated the extracellular levels of IL-1 beta and IL-6 from LPS-activated THP-1 cells without cytotoxic effect. For the signaling studies, C61-1 significantly inhibited LPS-induced ERK activation, IKK-alpha/beta phosphorylation and I kappa B-alpha degradation. In addition, our results shown 61-1 had the long-term inhibitory effect on Stat3 (Tyr705) phosphorylation (3 h to 24 h). Pre-treatment with AG490, a specific JAK2/STAT3 inhibitor, attenuated LPS-activated MMP-9-mediated gelatinolysis similarly, but C61-1 shown more potent inhibition of I kappa B-alpha degradation compared with AG490.
Conclusions:
These results indicated that C61-1 strongly attenuated MMP-9, IL-1 beta and IL-6 via regulating the duel pathways of STAT3 and NF-kappa B. The novel fungal sesquiterpene C61-1 might provide new opportunities for the development of different strategies on inflammatory and MMP-9 associated diseases.
