光污染是最严重的公共问题之一,尤其是夜光。然而,夜间暗蓝光(dLAN-BL)对认知功能的影响尚不清楚。在这项研究中,我们评估了连续4周暴露于dLAN-BL对C57BL/6J小鼠的影响。我们的结果表明,dLAN-BL显着损害了小鼠的空间学习和记忆,并增加了血浆皮质酮水平。与这些变化一致,我们观察到dLAN-BL显着增加海马中小胶质细胞的数量和激活以及氧化应激产物MDA的水平,降低抗氧化酶的水平谷胱甘肽过氧化物酶(GSH-Px),超氧化物歧化酶(SOD),谷胱甘肽还原酶(Gsr),总抗氧化剂(T-AOC)和海马神经元的数量,上调IL6、TNF-αmRNA表达水平和iNOS蛋白表达水平,COX2,TLR4,p-p65,Cleaved-Caspase3和BAX,并下调IL4,IL10,Psd95,Snap25,Sirt1,Dcx的mRNA表达水平和BCL2的蛋白表达水平。体外实验结果进一步显示皮质酮(10uM)诱导BV2细胞活化,上调细胞上清液中IL6、TNF-α的含量和iNOS的蛋白表达水平,BV2细胞中的COX2、p-p65。我们的发现提示dLAN-BL上调血浆皮质酮水平和海马小胶质细胞活化,进而导致氧化应激和神经炎症,导致神经元丢失和突触功能障碍,最终导致小鼠空间学习和记忆功能障碍。
Light pollution is one of the most serious public problems, especially the night light. However, the effect of dim blue light at night (dLAN-BL) on cognitive function is unclear. In this study, we evaluated the effects of exposure to dLAN-BL in C57BL/6J mice for 4 consecutive weeks. Our results showed dLAN-BL significantly impaired spatial learning and memory and increased plasma corticosterone level in mice. Consistent with these changes, we observed dLAN-BL significantly increased the numbers and activation of microglia and the levels of oxidative stress product MDA in the hippocampus, decreased the levels of antioxidant enzymes Glutathione peroxidase (GSH-Px), Superoxide dismutase (SOD), Gluathione reductase (Gsr), total antioxidants (T-AOC) and the number of neurons in the hippocampus, up-regulated the mRNA expression levels of IL6, TNF-α and the protein expression levels of iNOS, COX2, TLR4, p-p65, Cleaved-Caspase3 and BAX, and down-regulated the mRNA expression levels of IL4, IL10, Psd95, Snap25, Sirt1, Dcx and the protein expression level of BCL2. In vitro results further showed corticosterone (10uM)-induced BV2 cell activation and up-regulated content of IL6, TNF-α in the cell supernatant and the protein expression levels of iNOS, COX2, p-p65 in BV2 cells. Our findings suggested dLAN-BL up-regulated plasma corticosterone level and hippocampal microglia activation, which in turn caused oxidative stress and neuroinflammation, leading to neuronal loss and synaptic dysfunction, ultimately leading to spatial learning and memory dysfunction in mice.