• Journal of Marine Bioscience and Biotechnology
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• v.14 no.1
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• pp.33-42
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• 2022

Tacrolimus, a type of macrolide produced by Streptomyces tsukubaensis, is widely used as an immunosuppressant. However, continuous exposure to tacrolimus causes oxidative stress in normal cells, ultimately inducing cell injury. Therefore, this study investigated whether luthione, a reduced glutathione, could inhibit tacrolimus-induced cytotoxicity in olive flounder (hirame) natural embryo (HINAE) cells. According to the results, luthione significantly inhibited tacrolimus-induced reduction in cell viability in a concentration-dependent manner. Additinally, although luthione unaffected autophagy by tacrolimus, tacrolimus-induced apoptosis was significantly suppressed in the presence of luthione. Luthione also markedly blocked DNA damage in tacrolimus-treated HINAE cells, associated with the inhibition of reactive oxygen species (ROS) generation. Additionally, tacrolimus cytotoxicity in HINAE cells was correlated with increased inflammatory response, also attenuated by luthione. Collectively, these results show that at least luthione protects HINAE cells against tacrolimus-induced DNA damage, apoptosis, and inflammation, but not autophagy, by scavenging ROS. Although additional in-vivo studies are required, this study's results can be used as a basis for utilizing luthione to reduce the toxicity of fish cells caused by excessive immune responses.

• Journal of Life Science
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• v.33 no.5
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• pp.397-405
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• 2023

Although glutathione (GSH) has been shown to play an important role in the prevention of oxidative damage as an antioxidant, studies on immune regulation by it have not been properly conducted. In this study, we investigated whether luthione^®, a reduced GSH, has an immune enhancing effect in murine macrophage RAW 264.7 cells. The results of flow cytometry and immunofluorescence experiments indicated that luthione increased phagocytic activity, a representative function of macrophages, compared to the control cells. According to the results of the cytokine array, the expression of interleukin (IL)-5, IL-1β, and IL-27 was significantly increased in the luthione-treated cells. Luthione also enhanced the production of tumor necrosis factor-α and IL-1β through increased expression of their proteins, and increased release of the immune mediators such as nitric oxide (NO) and prostaglandin E₂ was associated with increased expression of inducible NO synthase and cyclooxygenase-2. In addition, the expression of cluster of differentiation 86, an M1 macrophage marker, was dramatically enhanced in RAW 264.7 cells treated with luthione. Furthermore, as a result of heat map analysis, we found that cytokine signaling 1/3-mediated signal transducer and activator of transcription/Janus tyrosine kinase signaling pathway was involved in the immunomodulatory effect by luthione. In conclusion, our data suggested that luthione could act as a molecular regulator in M1 macrophage polarization and enhance immune capacity by promoting macrophage phagocytic function.