Limits...
Anti-inflammatory effects of α-galactosylceramide analogs in activated microglia: involvement of the p38 MAPK signaling pathway.

Jeong YH, Kim Y, Song H, Chung YS, Park SB, Kim HS - PLoS ONE (2014)

Bottom Line: Here, we designed and synthesized α-galactosylceramide (α-GalCer) analogs to exert anti-inflammatory effects in activated microglia.After identification of 4d and 4e as hit compounds, we further investigated the underlying mechanism of their anti-inflammatory effects using RT-PCR analysis.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.

View Article: PubMed Central - PubMed

Affiliation: Department of Molecular Medicine and Global Top5 Research Program, Tissue Injury Defense Research Center, Ewha Womans University Medical School, Seoul, Republic of Korea.

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.

Show MeSH

Related in: MedlinePlus

Synthetic scheme of final modifications of the acyl chain resulting in 25 unique α-GalCer analogs.
© Copyright Policy
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC3921125&req=5

pone-0087030-g004: Synthetic scheme of final modifications of the acyl chain resulting in 25 unique α-GalCer analogs.

Mentions: After systematic introduction of five unique sphingosine backbones in 14a–e, we further diversified their acyl chains via a coupling reaction with various carboxylic acids after Staudinger reduction of the azide group or 1,3-dipolar cycloaddition of an azide group with a terminal alkyne (Figure 4). The EDCI-mediated amide coupling with either cerotic acid or lignoceric acid followed by global deprotection of six benzyl groups via catalytic hydrogenation in the presence of Pd(OH)2/C allowed the preparation of 1a–e or 2a–e as α-GalCer analogs with acyl chains of KRN7000 or OCH, respectively. Compounds 3a–e were prepared by amide coupling with octanoic acid as α-GalCer analogs containing a short eight-carbon acyl chain. For compounds 4a–e, the acyl chain region contains a 10-carbon-equivalent acyl chain with a terminal phenyl moiety for additional non-covalent interactions. As an isostere of amide bonds, triazole moiety was introduced via copper-mediated click reaction of the azide group in 14a–e with hexacos-1-yne at the acyl chain position to yield compounds 5a–e. Compound 1c is our reported TH2-selective α-GalCer analog [25], and the systematic diversification of this compound provided a collection of 25 α-GalCer analogs (1a–5e) as a focused library to identify novel anti-inflammatory agents for the treatment of neurodegenerative diseases.


Anti-inflammatory effects of α-galactosylceramide analogs in activated microglia: involvement of the p38 MAPK signaling pathway.

Jeong YH, Kim Y, Song H, Chung YS, Park SB, Kim HS - PLoS ONE (2014)

Synthetic scheme of final modifications of the acyl chain resulting in 25 unique α-GalCer analogs.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3921125&req=5

pone-0087030-g004: Synthetic scheme of final modifications of the acyl chain resulting in 25 unique α-GalCer analogs.
Mentions: After systematic introduction of five unique sphingosine backbones in 14a–e, we further diversified their acyl chains via a coupling reaction with various carboxylic acids after Staudinger reduction of the azide group or 1,3-dipolar cycloaddition of an azide group with a terminal alkyne (Figure 4). The EDCI-mediated amide coupling with either cerotic acid or lignoceric acid followed by global deprotection of six benzyl groups via catalytic hydrogenation in the presence of Pd(OH)2/C allowed the preparation of 1a–e or 2a–e as α-GalCer analogs with acyl chains of KRN7000 or OCH, respectively. Compounds 3a–e were prepared by amide coupling with octanoic acid as α-GalCer analogs containing a short eight-carbon acyl chain. For compounds 4a–e, the acyl chain region contains a 10-carbon-equivalent acyl chain with a terminal phenyl moiety for additional non-covalent interactions. As an isostere of amide bonds, triazole moiety was introduced via copper-mediated click reaction of the azide group in 14a–e with hexacos-1-yne at the acyl chain position to yield compounds 5a–e. Compound 1c is our reported TH2-selective α-GalCer analog [25], and the systematic diversification of this compound provided a collection of 25 α-GalCer analogs (1a–5e) as a focused library to identify novel anti-inflammatory agents for the treatment of neurodegenerative diseases.

Bottom Line: Here, we designed and synthesized α-galactosylceramide (α-GalCer) analogs to exert anti-inflammatory effects in activated microglia.After identification of 4d and 4e as hit compounds, we further investigated the underlying mechanism of their anti-inflammatory effects using RT-PCR analysis.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.

View Article: PubMed Central - PubMed

Affiliation: Department of Molecular Medicine and Global Top5 Research Program, Tissue Injury Defense Research Center, Ewha Womans University Medical School, Seoul, Republic of Korea.

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.

Show MeSH
Related in: MedlinePlus