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Reactive oxygen species induce Cox-2 expression via TAK1 activation in synovial fibroblast cells.

Onodera Y, Teramura T, Takehara T, Shigi K, Fukuda K - FEBS Open Bio (2015)

Bottom Line: Furthermore, we elucidated a novel mechanism, in which oxidative stress induced phosphorylation of MAPKs and NF-κB through TAK1 activation and resulted in increased Cox-2 and prostaglandin E2 expression.Finally, we demonstrated that ROS-induced Cox-2 expression was inhibited by supplementation of an antioxidant such as N-acetyl cysteamine and hyaluronic acid in vitro and in vivo.From these results, we conclude that oxidative stress is an important factor for generation of Cox-2 in synovial fibroblasts and thus its neutralization may be an effective strategy in palliative therapy for chronic joint diseases.

View Article: PubMed Central - PubMed

Affiliation: Division of Cell Biology for Regenerative Medicine, Institute of Advanced Clinical Medicine, Kindai University Faculty of Medicine, Osaka, Japan.

ABSTRACT
Oxidative stress within the arthritis joint has been indicated to be involved in generating mediators for tissue degeneration and inflammation. COX-2 is a mediator in inflammatory action, pain and some catabolic reactions in inflamed tissues. Here, we demonstrated a direct relationship between oxidative stress and Cox-2 expression in the bovine synovial fibroblasts. Furthermore, we elucidated a novel mechanism, in which oxidative stress induced phosphorylation of MAPKs and NF-κB through TAK1 activation and resulted in increased Cox-2 and prostaglandin E2 expression. Finally, we demonstrated that ROS-induced Cox-2 expression was inhibited by supplementation of an antioxidant such as N-acetyl cysteamine and hyaluronic acid in vitro and in vivo. From these results, we conclude that oxidative stress is an important factor for generation of Cox-2 in synovial fibroblasts and thus its neutralization may be an effective strategy in palliative therapy for chronic joint diseases.

No MeSH data available.


Related in: MedlinePlus

Antioxidants attenuate ROS-mediated Cox2 and PGE2 expressions. (A) Estimation of the intracellular ROS levels in the cells treated with 100 μM H2O2 and 100 μM NAC or 2 mg/ml HA. (B) qPCR analysis for Cox-2 expression in the SFs treated with H2O2 and 100 μM NAC or HA at 0.5, 1, 2 and 5 mg/ml. (C) WB showing suppression of TAK1 phosphorylation and Cox2 expression in the cells treated with NAC and HA. (D) ELISA assays for PGE2 expression in the SFs treated with 100 μM H2O2, 100 μM NAC and 2 mg/ml HA.
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f0020: Antioxidants attenuate ROS-mediated Cox2 and PGE2 expressions. (A) Estimation of the intracellular ROS levels in the cells treated with 100 μM H2O2 and 100 μM NAC or 2 mg/ml HA. (B) qPCR analysis for Cox-2 expression in the SFs treated with H2O2 and 100 μM NAC or HA at 0.5, 1, 2 and 5 mg/ml. (C) WB showing suppression of TAK1 phosphorylation and Cox2 expression in the cells treated with NAC and HA. (D) ELISA assays for PGE2 expression in the SFs treated with 100 μM H2O2, 100 μM NAC and 2 mg/ml HA.

Mentions: As the last part of the study, we examined if the supplementation of antioxidant could suppress the ROS-induced Cox-2 expression both in vitro and in vivo. When we treated the SFs with H2O2 and NAC, which is a potent ROS scavenger due to its cysteine residues, accumulation of intracellular ROS was blocked (Fig. 4A). HA is also a potent ROS scavengers [30,31]. Importantly, phosphorylation of TAK1 was inhibited in both NAC and HA-added conditions (Fig. 4B) and Cox-2 expression was repressed to the similar level with that of the baseline control by treatment with the antioxidants (Fig. 4C). Then we observed PGE2 expression in H2O2 and HA or NAC treated cells by ELISA. The ELISA assay clearly showed that the expression of PGE2 was also significantly attenuated in HA or NAC-treated cells (Fig. 4D). Finally, we tried to observe the relationship between TAK1, Cox-2 and HA in the surgical OA models, which has significant synovial expansion and inflammation.


Reactive oxygen species induce Cox-2 expression via TAK1 activation in synovial fibroblast cells.

Onodera Y, Teramura T, Takehara T, Shigi K, Fukuda K - FEBS Open Bio (2015)

Antioxidants attenuate ROS-mediated Cox2 and PGE2 expressions. (A) Estimation of the intracellular ROS levels in the cells treated with 100 μM H2O2 and 100 μM NAC or 2 mg/ml HA. (B) qPCR analysis for Cox-2 expression in the SFs treated with H2O2 and 100 μM NAC or HA at 0.5, 1, 2 and 5 mg/ml. (C) WB showing suppression of TAK1 phosphorylation and Cox2 expression in the cells treated with NAC and HA. (D) ELISA assays for PGE2 expression in the SFs treated with 100 μM H2O2, 100 μM NAC and 2 mg/ml HA.
© Copyright Policy - CC BY
Related In: Results  -  Collection

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getmorefigures.php?uid=PMC4476901&req=5

f0020: Antioxidants attenuate ROS-mediated Cox2 and PGE2 expressions. (A) Estimation of the intracellular ROS levels in the cells treated with 100 μM H2O2 and 100 μM NAC or 2 mg/ml HA. (B) qPCR analysis for Cox-2 expression in the SFs treated with H2O2 and 100 μM NAC or HA at 0.5, 1, 2 and 5 mg/ml. (C) WB showing suppression of TAK1 phosphorylation and Cox2 expression in the cells treated with NAC and HA. (D) ELISA assays for PGE2 expression in the SFs treated with 100 μM H2O2, 100 μM NAC and 2 mg/ml HA.
Mentions: As the last part of the study, we examined if the supplementation of antioxidant could suppress the ROS-induced Cox-2 expression both in vitro and in vivo. When we treated the SFs with H2O2 and NAC, which is a potent ROS scavenger due to its cysteine residues, accumulation of intracellular ROS was blocked (Fig. 4A). HA is also a potent ROS scavengers [30,31]. Importantly, phosphorylation of TAK1 was inhibited in both NAC and HA-added conditions (Fig. 4B) and Cox-2 expression was repressed to the similar level with that of the baseline control by treatment with the antioxidants (Fig. 4C). Then we observed PGE2 expression in H2O2 and HA or NAC treated cells by ELISA. The ELISA assay clearly showed that the expression of PGE2 was also significantly attenuated in HA or NAC-treated cells (Fig. 4D). Finally, we tried to observe the relationship between TAK1, Cox-2 and HA in the surgical OA models, which has significant synovial expansion and inflammation.

Bottom Line: Furthermore, we elucidated a novel mechanism, in which oxidative stress induced phosphorylation of MAPKs and NF-κB through TAK1 activation and resulted in increased Cox-2 and prostaglandin E2 expression.Finally, we demonstrated that ROS-induced Cox-2 expression was inhibited by supplementation of an antioxidant such as N-acetyl cysteamine and hyaluronic acid in vitro and in vivo.From these results, we conclude that oxidative stress is an important factor for generation of Cox-2 in synovial fibroblasts and thus its neutralization may be an effective strategy in palliative therapy for chronic joint diseases.

View Article: PubMed Central - PubMed

Affiliation: Division of Cell Biology for Regenerative Medicine, Institute of Advanced Clinical Medicine, Kindai University Faculty of Medicine, Osaka, Japan.

ABSTRACT
Oxidative stress within the arthritis joint has been indicated to be involved in generating mediators for tissue degeneration and inflammation. COX-2 is a mediator in inflammatory action, pain and some catabolic reactions in inflamed tissues. Here, we demonstrated a direct relationship between oxidative stress and Cox-2 expression in the bovine synovial fibroblasts. Furthermore, we elucidated a novel mechanism, in which oxidative stress induced phosphorylation of MAPKs and NF-κB through TAK1 activation and resulted in increased Cox-2 and prostaglandin E2 expression. Finally, we demonstrated that ROS-induced Cox-2 expression was inhibited by supplementation of an antioxidant such as N-acetyl cysteamine and hyaluronic acid in vitro and in vivo. From these results, we conclude that oxidative stress is an important factor for generation of Cox-2 in synovial fibroblasts and thus its neutralization may be an effective strategy in palliative therapy for chronic joint diseases.

No MeSH data available.


Related in: MedlinePlus