Abstract

Recent evidence has shown that salmon calcitonin (sCT) has positive effects on the nervous system. However, its effect and mechanisms on glutamate-induced cytotoxicity are still unclear. The current experiment was designed to examine the effect of sCT on glutamate-induced cytotoxicity in C6 cells, involving the inflammatory and nitric oxide stress pathways. The study used the C6 glioma cell line. Four cell groups were prepared to evaluate the effect of sCT on glutamate-induced cytotoxicity. The control group was without any treatment. Cells in the glutamate group were treated with 10 mM glutamate for 24 h. Cells in the sCT group were treated with various concentrations (3, 6, 12, 25, and 50 µg/mL) of sCT for 24 h. Cells in the sCT + glutamate group were pre-treated with various concentrations of sCT for 1 h and then exposed to glutamate for 24 h. The cell viability was evaluated with an XTT assay. Nuclear factor kappa b (NF-kB), tumor necrosis factor alpha (TNF-α), interleukin-6 (IL-6), neuronal nitric oxide synthase (nNOS), nitric oxide (NO), cyclic guanosine monophosphate (cGMP), caspase-3, and caspase-9 levels in the cells were measured by ELISA kits. Apoptosis was detected by flow cytometry method. sCT at all concentrations significantly improved the cell viability in C6 cells after glutamate-induced cytotoxicity (p < 0.001). Moreover, sCT significantly reduced the levels of NF-kB (p < 0.001), TNF-α, and IL-6 levels (p < 0.001). sCT also decreased nNOS, NO, and cGMP levels (P < 0.001). Furthermore, it decreased the apoptosis rate and increased the live-cell rate in the flow cytometry (P < 0.001). In conclusion, sCT has protective effects on glutamate-induced cytotoxicity in C6 glial cells by inhibiting inflammatory and nitric oxide pathways. sCT could be a useful supportive agent for people with neurodegenerative symptoms.

Graphic abstract

中文翻译：

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鲑鱼降钙素对 C6 细胞系中谷氨酸诱导的细胞毒性的影响以及炎症和一氧化氮途径所起的作用

摘要

最近的证据表明，鲑鱼降钙素 (sCT) 对神经系统有积极作用。然而，其对谷氨酸诱导的细胞毒性的作用和机制仍不清楚。目前的实验旨在检查 sCT 对 C6 细胞中谷氨酸诱导的细胞毒性的影响，涉及炎症和一氧化氮应激途径。该研究使用了 C6 神经胶质瘤细胞系。制备了四个细胞组以评估 sCT 对谷氨酸诱导的细胞毒性的影响。对照组不做任何处理。谷氨酸组细胞用 10 mM 谷氨酸处理 24 h。sCT 组中的细胞用不同浓度（3、6、12、25 和 50 µg/mL）的 sCT 处理 24 小时。sCT + 谷氨酸组的细胞用不同浓度的 sCT 预处理 1 小时，然后暴露于谷氨酸 24 小时。用 XTT 测定法评估细胞活力。核因子 kappa b (NF-kB)、肿瘤坏死因子 α (TNF-α)、白细胞介素-6 (IL-6)、神经元一氧化氮合酶 (nNOS)、一氧化氮 (NO)、环磷酸鸟苷 (cGMP)、通过ELISA试剂盒测量细胞中的caspase-3和caspase-9水平。流式细胞仪检测细胞凋亡。在谷氨酸诱导的细胞毒性后，所有浓度的 sCT 显着提高了 C6 细胞的细胞活力（p < 0.001）。此外，sCT 显着降低了 NF-kB (p < 0.001)、TNF-α 和 IL-6 水平 (p < 0.001)。sCT 还降低了 nNOS、NO 和 cGMP 水平（P < 0.001）。此外，它降低了细胞凋亡率并增加了流式细胞仪中的活细胞率（P <0.001）。综上所述，sCT 通过抑制炎症和一氧化氮途径对 C6 神经胶质细胞中谷氨酸诱导的细胞毒性具有保护作用。对于有神经退行性症状的人，sCT 可能是一种有用的支持剂。

图形摘要