Abstract
Microglial activation plays a pivotal role in the development and progression of neurodegenerative diseases. Thus, anti-inflammatory agents that control microglial activation can serve as potential therapeutic agents for neurodegenerative diseases. Here, we designed and synthesized α-galactosylceramide (α-GalCer) analogs to exert anti-inflammatory effects in activated microglia. We performed biological evaluations of 25 α-GalCer analogs and observed an interesting preliminary structure-activity relationship in their inhibitory influence on NO release and TNF-α production in LPS-stimulated BV2 microglial cells. After identification of 4d and 4e as hit compounds, we further investigated the underlying mechanism of their anti-inflammatory effects using RT-PCR analysis. We confirmed that 4d and 4e regulate the expression of iNOS, COX-2, IL-1β, and IL-6 at the mRNA level and the expression of TNF-α at the post-transcriptional level. In addition, both 4d and 4e inhibited LPS-induced DNA binding activities of NF-κB and AP-1 and phosphorylation of p38 MAPK without affecting other MAP kinases. When we examined the anti-inflammatory effect of a p38 MAPK-specific inhibitor, SB203580, on microglial activation, we observed an identical inhibitory pattern as that of 4d and 4e, not only on NO and TNF-α production but also on the DNA binding activities of NF-κB and AP-1. Taken together, these results suggest that p38 MAPK plays an important role in the anti-inflammatory effects of 4d and 4e via the modulation of NF-κB and AP-1 activities.
Publication types
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Research Support, Non-U.S. Gov't
MeSH terms
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Animals
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Anti-Inflammatory Agents / chemistry*
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Cell Line
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Cell Survival
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Cells, Cultured
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Cyclooxygenase 2 / metabolism
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DNA / chemistry
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Galactosylceramides / chemistry*
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Gene Expression Regulation, Enzymologic*
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Imidazoles / chemistry
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Interleukin-1beta / metabolism
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Interleukin-6 / metabolism
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Lipopolysaccharides / chemistry
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MAP Kinase Signaling System*
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Mice
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Microglia / metabolism*
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NF-kappa B / metabolism
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Nitric Oxide Synthase Type II / metabolism
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Phosphorylation
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Protein Kinase Inhibitors / chemistry
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Pyridines / chemistry
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Transcription Factor AP-1 / metabolism
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p38 Mitogen-Activated Protein Kinases / metabolism*
Substances
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Anti-Inflammatory Agents
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Galactosylceramides
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Imidazoles
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Interleukin-1beta
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Interleukin-6
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Lipopolysaccharides
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NF-kappa B
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Protein Kinase Inhibitors
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Pyridines
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Transcription Factor AP-1
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alpha-galactosylceramide
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interleukin-6, mouse
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DNA
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Nitric Oxide Synthase Type II
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Nos2 protein, mouse
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Ptgs2 protein, mouse
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Cyclooxygenase 2
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p38 Mitogen-Activated Protein Kinases
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SB 203580
Grants and funding
This work was supported by the MRC Grant (2012R1A5A2A32671866), and the Basic Science Research Program (2010-0004008) to HS Kim, and the Bio & Medical Technology Development Program (2012M3A9C4048780), a Global Frontier Project Grant (2013M3A6A4044245), and the Basic Research Laboratory (2010-0019766) to SB Park, funded by the National Research Foundation of Korea. YK and HS are grateful for a BK21 Scholarship. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.