USDA-ARS, Human Nutrition Research Center on Aging at Tufts University, Boston, MA 02111, USA.
Department of Psychology, University of Maryland, Baltimore County (UMBC), Baltimore, MD 21250, USA.
Int J Mol Sci. 2024 May 29;25(11):5923. doi: 10.3390/ijms25115923.
Astronauts on exploratory missions will be exposed to galactic cosmic rays (GCR), which can induce neuroinflammation and oxidative stress (OS) and may increase the risk of neurodegenerative disease. As key regulators of inflammation and OS in the CNS, microglial cells may be involved in GCR-induced deficits, and therefore could be a target for neuroprotection. This study assessed the effects of exposure to helium (He) and iron (Fe) particles on inflammation and OS in microglia in vitro, to establish a model for testing countermeasure efficacy. Rat microglia were exposed to a single dose of 20 cGy (300 MeV/n) He or 2 Gy Fe (600 MeV/n), while the control cells were not exposed (0 cGy). Immediately following irradiation, fresh media was applied to the cells, and biomarkers of inflammation (cyclooxygenase-2 [COX-2], nitric oxide synthase [iNOS], phosphorylated IκB-α [pIκB-α], tumor necrosis factor-α [TNFα], and nitrite [NO]) and OS (NADPH oxidase [NOX2]) were assessed 24 h later using standard immunochemical techniques. Results showed that radiation did not increase levels of NO or protein levels of COX-2, iNOS, pIκB-α, TNFα, or NOX2 compared to non-irradiated control conditions in microglial cells ( > 0.05). Therefore, microglia in isolation may not be the primary cause of neuroinflammation and OS following exposures to helium or iron GCR particles.
宇航员在探索任务中会暴露在银河宇宙射线（GCR）下，这可能会引起神经炎症和氧化应激（OS），并增加神经退行性疾病的风险。作为中枢神经系统中炎症和 OS 的关键调节剂，小胶质细胞可能参与了 GCR 诱导的损伤，因此可能成为神经保护的靶点。本研究评估了暴露于氦（He）和铁（Fe）颗粒对体外小胶质细胞炎症和 OS 的影响，为测试对策功效建立了模型。用 20 cGy（300 MeV/n）He 或 2 Gy Fe（600 MeV/n）对大鼠小胶质细胞进行单次照射，而对照细胞不进行照射（0 cGy）。照射后立即向细胞中添加新鲜培养基，24 小时后使用标准免疫化学技术评估炎症标志物（环氧化酶-2 [COX-2]、一氧化氮合酶 [iNOS]、磷酸化 IκB-α [pIκB-α]、肿瘤坏死因子-α [TNFα]和亚硝酸盐 [NO]）和 OS（NADPH 氧化酶 [NOX2]）。结果表明，与未照射对照条件相比，辐射不会增加小胶质细胞中 NO 或 COX-2、iNOS、pIκB-α、TNFα 或 NOX2 的蛋白水平（>0.05）。因此，在单独暴露于氦或铁 GCR 颗粒后，小胶质细胞可能不是神经炎症和 OS 的主要原因。
