Department of Food Science and Nutrition, Faculty of Science, The Hong Kong Polytechnic University, Hong Kong SAR, China.
Research Institute for Future Food, The Hong Kong Polytechnic University, Hong Kong SAR, China.
Int J Mol Sci. 2024 Jul 7;25(13):7458. doi: 10.3390/ijms25137458.
Circadian rhythms regulate physiological processes in approximately 24 h cycles, and their disruption is associated with various diseases. Inflammation may perturb circadian rhythms, though these interactions remain unclear. This study examined whether systemic inflammation induced by an intraperitoneal injection of lipopolysaccharide (LPS) could alter central and peripheral circadian rhythms and diurnal neuroimmune dynamics. Mice were randomly assigned to two groups: the saline control group and the LPS group. The diurnal expression of circadian clock genes and inflammatory cytokines were measured in the hypothalamus, hippocampus, and liver. Diurnal dynamic behaviors of microglia were also assessed. Our results revealed that the LPS perturbed circadian gene oscillations in the hypothalamus, hippocampus, and liver. Furthermore, systemic inflammation induced by the LPS could trigger neuroinflammation and perturb the diurnal dynamic behavior of microglia in the hippocampus. These findings shed light on the intricate link between inflammation and circadian disruption, underscoring their significance in relation to neurodegenerative diseases.
昼夜节律以大约 24 小时的周期调节生理过程，其紊乱与各种疾病有关。炎症可能会扰乱昼夜节律，但这些相互作用尚不清楚。本研究旨在探讨腹腔注射脂多糖 (LPS) 引起的全身炎症是否会改变中枢和外周昼夜节律以及昼夜神经免疫动态。将小鼠随机分为两组：生理盐水对照组和 LPS 组。测量下丘脑、海马和肝脏中昼夜节律钟基因和炎性细胞因子的表达。还评估了小胶质细胞的昼夜动态行为。我们的结果表明，LPS 扰乱了下丘脑、海马和肝脏中昼夜节律基因的振荡。此外，LPS 引起的全身炎症可引发神经炎症并扰乱海马中小胶质细胞的昼夜动态行为。这些发现揭示了炎症和昼夜节律紊乱之间复杂的联系，强调了它们与神经退行性疾病的关系的重要性。
