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Mitochondria-targeted antioxidant MitoQ ameliorates experimental mouse colitis by suppressing NLRP3 inflammasome-mediated inflammatory cytokines.

Dashdorj A, Jyothi KR, Lim S, Jo A, Nguyen MN, Ha J, Yoon KS, Kim HJ, Park JH, Murphy MP, Kim SS - BMC Med (2013)

Bottom Line: The effect of MitoQ on inflammatory cytokines released in the human macrophage-like cell line THP-1 was also analyzed.In vitro studies demonstrated that MitoQ decreases IL-1 beta and IL-18 production in human THP-1 cells.Taken together, our results suggest that MitoQ may have potential as a novel therapeutic agent for the treatment of acute phases of inflammatory bowel disease.

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Biochemistry and Molecular Biology, School of Medicine, Kyung Hee University, Seoul 130-701, Republic of Korea.

ABSTRACT

Background: MitoQ is a mitochondria-targeted derivative of the antioxidant ubiquinone, with antioxidant and anti-apoptotic functions. Reactive oxygen species are involved in many inflammatory diseases including inflammatory bowel disease. In this study, we assessed the therapeutic effects of MitoQ in a mouse model of experimental colitis and investigated the possible mechanisms underlying its effects on intestinal inflammation.

Methods: Reactive oxygen species levels and mitochondrial function were measured in blood mononuclear cells of patients with inflammatory bowel disease. The effects of MitoQ were evaluated in a dextran sulfate sodium-induced colitis mouse model. Clinical and pathological markers of disease severity and oxidative injury, and levels of inflammatory cytokines in mouse colonic tissue were measured. The effect of MitoQ on inflammatory cytokines released in the human macrophage-like cell line THP-1 was also analyzed.

Results: Cellular and mitochondrial reactive oxygen species levels in mononuclear cells were significantly higher in patients with inflammatory bowel disease (P <0.003, cellular reactive oxygen species; P <0.001, mitochondrial reactive oxygen species). MitoQ significantly ameliorated colitis in the dextran sulfate sodium-induced mouse model in vivo, reduced the increased oxidative stress response (malondialdehyde and 3-nitrotyrosine formation), and suppressed mitochondrial and histopathological injury by decreasing levels of inflammatory cytokines IL-1 beta and IL-18 (P <0.001 and P <0.01 respectively). By decreasing mitochondrial reactive oxygen species, MitoQ also suppressed activation of the NLRP3 inflammasome that was responsible for maturation of IL-1 beta and IL-18. In vitro studies demonstrated that MitoQ decreases IL-1 beta and IL-18 production in human THP-1 cells.

Conclusion: Taken together, our results suggest that MitoQ may have potential as a novel therapeutic agent for the treatment of acute phases of inflammatory bowel disease.

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MitoQ suppresses caspase-1-mediated IL-1 beta and IL-18 release during colitis. ELISA assay for (A) IL-1 beta or (B) IL-18 were performed in colon homogenates. Results are expressed as mean ±SE. n=5. *P <0.001,**P<0.01. (C) mRNA expression levels of IL-1 beta and IL-18 in colon tissue were examined by RT-PCR. (D) Cleavages of caspase-1, IL-1 beta and IL-18 were analyzed by western blotting analysis in colon homogenates.
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Figure 5: MitoQ suppresses caspase-1-mediated IL-1 beta and IL-18 release during colitis. ELISA assay for (A) IL-1 beta or (B) IL-18 were performed in colon homogenates. Results are expressed as mean ±SE. n=5. *P <0.001,**P<0.01. (C) mRNA expression levels of IL-1 beta and IL-18 in colon tissue were examined by RT-PCR. (D) Cleavages of caspase-1, IL-1 beta and IL-18 were analyzed by western blotting analysis in colon homogenates.

Mentions: We next asked whether an activated inflammasome leads to enhanced release of IL-1 beta and IL-18 during colitis. Release of the active inflammatory cytokines IL-1 beta and IL-18 is mediated by a two-step process: first, recognition of pro-inflammatory signals by pattern recognition receptors on host cells and activation of pro-IL-1 beta and pro-IL-18 promoters; second, activation of the inflammasome by danger signals, resulting in activation of caspase-1 and cleavage of pro-IL-1 beta and pro-IL-18 [37]. Therefore, we evaluated how MitoQ affects the release of these cytokines in colon homogenates. Levels of IL-1 beta and IL-18 were significantly higher in DSS- and DSS+dTPP-treated mice than in control and DSS+MitoQ-treated mice, suggesting that MitoQ suppresses the release of these cytokines (Figure 5A,B). Furthermore, the mRNA levels of IL-1 beta and IL-18 were higher in DSS- and DSS+dTPP-treated mice, but suppressed with MitoQ treatment (Figure 5C). Lastly, western blotting analysis demonstrated the increased level of cleaved forms of caspase-1, IL-1 beta and IL-18 in the colon of DSS- and DSS+dTPP-treated mice, but the decreased cleavage in control and DSS+MitoQ-treated mice (Figure 5D). These data clearly demonstrate that MitoQ not only suppresses release of the active forms of IL-1 beta and IL-18, but also their transcriptional up-regulation.


Mitochondria-targeted antioxidant MitoQ ameliorates experimental mouse colitis by suppressing NLRP3 inflammasome-mediated inflammatory cytokines.

Dashdorj A, Jyothi KR, Lim S, Jo A, Nguyen MN, Ha J, Yoon KS, Kim HJ, Park JH, Murphy MP, Kim SS - BMC Med (2013)

MitoQ suppresses caspase-1-mediated IL-1 beta and IL-18 release during colitis. ELISA assay for (A) IL-1 beta or (B) IL-18 were performed in colon homogenates. Results are expressed as mean ±SE. n=5. *P <0.001,**P<0.01. (C) mRNA expression levels of IL-1 beta and IL-18 in colon tissue were examined by RT-PCR. (D) Cleavages of caspase-1, IL-1 beta and IL-18 were analyzed by western blotting analysis in colon homogenates.
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Related In: Results  -  Collection

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Figure 5: MitoQ suppresses caspase-1-mediated IL-1 beta and IL-18 release during colitis. ELISA assay for (A) IL-1 beta or (B) IL-18 were performed in colon homogenates. Results are expressed as mean ±SE. n=5. *P <0.001,**P<0.01. (C) mRNA expression levels of IL-1 beta and IL-18 in colon tissue were examined by RT-PCR. (D) Cleavages of caspase-1, IL-1 beta and IL-18 were analyzed by western blotting analysis in colon homogenates.
Mentions: We next asked whether an activated inflammasome leads to enhanced release of IL-1 beta and IL-18 during colitis. Release of the active inflammatory cytokines IL-1 beta and IL-18 is mediated by a two-step process: first, recognition of pro-inflammatory signals by pattern recognition receptors on host cells and activation of pro-IL-1 beta and pro-IL-18 promoters; second, activation of the inflammasome by danger signals, resulting in activation of caspase-1 and cleavage of pro-IL-1 beta and pro-IL-18 [37]. Therefore, we evaluated how MitoQ affects the release of these cytokines in colon homogenates. Levels of IL-1 beta and IL-18 were significantly higher in DSS- and DSS+dTPP-treated mice than in control and DSS+MitoQ-treated mice, suggesting that MitoQ suppresses the release of these cytokines (Figure 5A,B). Furthermore, the mRNA levels of IL-1 beta and IL-18 were higher in DSS- and DSS+dTPP-treated mice, but suppressed with MitoQ treatment (Figure 5C). Lastly, western blotting analysis demonstrated the increased level of cleaved forms of caspase-1, IL-1 beta and IL-18 in the colon of DSS- and DSS+dTPP-treated mice, but the decreased cleavage in control and DSS+MitoQ-treated mice (Figure 5D). These data clearly demonstrate that MitoQ not only suppresses release of the active forms of IL-1 beta and IL-18, but also their transcriptional up-regulation.

Bottom Line: The effect of MitoQ on inflammatory cytokines released in the human macrophage-like cell line THP-1 was also analyzed.In vitro studies demonstrated that MitoQ decreases IL-1 beta and IL-18 production in human THP-1 cells.Taken together, our results suggest that MitoQ may have potential as a novel therapeutic agent for the treatment of acute phases of inflammatory bowel disease.

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Biochemistry and Molecular Biology, School of Medicine, Kyung Hee University, Seoul 130-701, Republic of Korea.

ABSTRACT

Background: MitoQ is a mitochondria-targeted derivative of the antioxidant ubiquinone, with antioxidant and anti-apoptotic functions. Reactive oxygen species are involved in many inflammatory diseases including inflammatory bowel disease. In this study, we assessed the therapeutic effects of MitoQ in a mouse model of experimental colitis and investigated the possible mechanisms underlying its effects on intestinal inflammation.

Methods: Reactive oxygen species levels and mitochondrial function were measured in blood mononuclear cells of patients with inflammatory bowel disease. The effects of MitoQ were evaluated in a dextran sulfate sodium-induced colitis mouse model. Clinical and pathological markers of disease severity and oxidative injury, and levels of inflammatory cytokines in mouse colonic tissue were measured. The effect of MitoQ on inflammatory cytokines released in the human macrophage-like cell line THP-1 was also analyzed.

Results: Cellular and mitochondrial reactive oxygen species levels in mononuclear cells were significantly higher in patients with inflammatory bowel disease (P <0.003, cellular reactive oxygen species; P <0.001, mitochondrial reactive oxygen species). MitoQ significantly ameliorated colitis in the dextran sulfate sodium-induced mouse model in vivo, reduced the increased oxidative stress response (malondialdehyde and 3-nitrotyrosine formation), and suppressed mitochondrial and histopathological injury by decreasing levels of inflammatory cytokines IL-1 beta and IL-18 (P <0.001 and P <0.01 respectively). By decreasing mitochondrial reactive oxygen species, MitoQ also suppressed activation of the NLRP3 inflammasome that was responsible for maturation of IL-1 beta and IL-18. In vitro studies demonstrated that MitoQ decreases IL-1 beta and IL-18 production in human THP-1 cells.

Conclusion: Taken together, our results suggest that MitoQ may have potential as a novel therapeutic agent for the treatment of acute phases of inflammatory bowel disease.

Show MeSH
Related in: MedlinePlus