Location: Diet, Genomics and Immunology LaboratoryTitle: Methyl (E)-(3,4-dihydroxyphenyl)acryloyl)tryptophanate can suppress MCP-1 expression by inhibiting p38 MAP kinase and NF-kB in LPS-stimulated differentiated THP-1 cells
Submitted to: European Journal of Pharmacology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 5/27/2017
Publication Date: 6/30/2017
Citation: Park, J.B., Wang, T.T. 2017. Methyl (E)-(3,4-dihydroxyphenyl)acryloyl)tryptophanate can suppress MCP-1 expression by inhibiting p38 MAP kinase and NF-kB in LPS-stimulated differentiated THP-1 cells. European Journal of Pharmacology. 8(10):149-155.. https://doi.org/10.1016/j.ejphar.2017.07.006.
Interpretive Summary: Monocyte chemotactic factor-1 (MCP-1) is a potent chemotactic factor, whose expression is reported to be ubiquitous in many different cell types and is often up-regulated by a wide variety of stimuli such as lipopolysaccharide (LPS). Because MCP-1 has a strong chemotactic activity on inflammatory cells, this protein helps recruit blood monocytes into the vessel wall, thereby leading to systemic vascular inflammation commonly observed in cardiovascular disease (CVD) and chronic kidney diseases (CKD) (5-8). In this study, we found that javamide-II-O methyl ester may have anti-inflammatory activity stronger than a parent chemical javamide-II found in coffee, and the compound could inhibit MCP-1 production in LPS-stimulated differentiated THP cells by inhibiting p38 kinase/ATF-2 phosphorylation and NF-kB. This study provides new information about javamide-II-O methyl ester to suppress MCP-1 expression in the cells, which could be utilized in MCP-1-related inflammatory diseases.
Technical Abstract: The p38 MAP kinase and NF-kB play significant roles in regulating the production of proinflammatory cytokines including monocyte chemotactic factor-1 (MCP-1). Therefore, potent inhibitors to suppress p38 kinase and NF-kB activities have been explored as anti-inflammatory agents. In this study, a novel compound methyl (E)-(3-(4-hydroxyphenyl)acryloyl)tryptophanate (MHAT) was synthesized and its potential effects on p38 MAP kinase and NF-kB were investigated in differentiated THP-1 cells. MHAT was able to inhibit p38 MAP kinase (IC50 of 18 microM) which was also supported by a silico model showing a stronger binding to p38 MAP kinase. The inhibition of p38 kinase by MHAT was able to reduce ATF-2 phosphorylation, a down-stream molecule of its signal pathway. Additionally, MHAT inhibited NF-kB(p65) phosphorylation, suggesting reduced NF-kB transcriptional activity. This was also confirmed by a NF-kB reporter study showing that MHAT could suppress NF-kB transcriptional activity by 25-40% (P < 0.05) in the NF-'B reporter (Luc)-HEK293 cell line. Since MHAT inhibited both p38 MAP kinase and NF-kB, we investigated its effects on their down-stream effector MCP-1 mRNA expression in differentiated THP-1 cells. The treatment with MHAT significantly down-regulated MCP-1 the mRNA expression in the THP-1 cells (P < 0.05). In line with the down-regulation of MCP-1 mRNA, at the protein levels, MHAT also suppressed the LPS-induced production of MCP-1 protein by 10-45% (P < 0.05) in the THP-1 cells. These data suggest that the inhibition of p38 kinase/ATF-2 phosphorylation and NF-kB could be an underling mechanism for MHAT to inhibit MCP-1 production in LPS-stimulated differentiated THP cells.