Abstract：
BACKGROUND: Neuroinflammation assumes a pivotal role in both the etiological underpinnings and the dynamic progression of sepsis-associated encephalopathy (SAE). The occurrence of cognitive deficits with SAE is associated with neuroinflammation. 4-phenyl butyrate (4-PBA) may control inflammation by inhibiting endoplasmic reticulum stress (ERS). The primary objective of this investigation is to scrutinize the effectiveness of 4-PBA in mitigating neuroinflammation induced by lipopolysaccharides (LPS) and its consequent impact on cognitive function decline.
METHODS: LPS-injected mice with SAE and LPS-treated BV2 cell were established to serve as experimental paradigms, both contributing to the investigative framework of the study. Cognitive functions were assessed by behavioral tests. Hippocampal neuronal damage was assessed using Golgi staining and Nissl staining. Quantitative PCR assay and immunofluorescence were used to analyze neuroinflammation. Mitochondrial function was examined using transmission electron microscopy. Protein expression analysis was conducted through the application of western blotting methodology, serving as the investigative approach to elucidate molecular signatures in the experimental framework. Endoplasmic reticulum and mitochondrial calcium flow were detected using flow cytometry. To delve deeper into the mechanistic intricacies, the administration of 4μ8c was employed to selectively impede the IRE1α/Xbp1s pathway, constituting a strategic intervention aimed at elucidating underlying regulatory processes.
RESULTS: Expression levels of ERS-related proteins exhibited a significant upregulation in hippocampal tissues of LPS-treated mice when compared to wild-type (WT) counterparts. The administration of 4-PBA notably ameliorated memory deficits in LPS-treated mice. Furthermore, 4-PBA treatment was found to alleviate oxidative stress and neuroinflammation. Mechanistically, the IRE1α/Xbp1s-Ca2+ signaling pathway played a crucial role in mediating the beneficial effects of mitigating oxidative stress and maintaining mitochondrial calcium homeostasis, with inhibition of the IRE-related pathway displaying opposing effects.
CONCLUSIONS: Our results suggest that administration of 4-PBA treatment significantly attenuates ERS, alleviates cognitive decline, reduces inflammatory damage, and restores mitochondrial dynamics via the IRE1α/Xbp1s-Ca2+-associated pathway, which provides a new potential therapeutic approach to SAE.
METHODS: LPS-injected mice with SAE and LPS-treated BV2 cell were established to serve as experimental paradigms, both contributing to the investigative framework of the study. Cognitive functions were assessed by behavioral tests. Hippocampal neuronal damage was assessed using Golgi staining and Nissl staining. Quantitative PCR assay and immunofluorescence were used to analyze neuroinflammation. Mitochondrial function was examined using transmission electron microscopy. Protein expression analysis was conducted through the application of western blotting methodology, serving as the investigative approach to elucidate molecular signatures in the experimental framework. Endoplasmic reticulum and mitochondrial calcium flow were detected using flow cytometry. To delve deeper into the mechanistic intricacies, the administration of 4μ8c was employed to selectively impede the IRE1α/Xbp1s pathway, constituting a strategic intervention aimed at elucidating underlying regulatory processes.
RESULTS: Expression levels of ERS-related proteins exhibited a significant upregulation in hippocampal tissues of LPS-treated mice when compared to wild-type (WT) counterparts. The administration of 4-PBA notably ameliorated memory deficits in LPS-treated mice. Furthermore, 4-PBA treatment was found to alleviate oxidative stress and neuroinflammation. Mechanistically, the IRE1α/Xbp1s-Ca2+ signaling pathway played a crucial role in mediating the beneficial effects of mitigating oxidative stress and maintaining mitochondrial calcium homeostasis, with inhibition of the IRE-related pathway displaying opposing effects.
CONCLUSIONS: Our results suggest that administration of 4-PBA treatment significantly attenuates ERS, alleviates cognitive decline, reduces inflammatory damage, and restores mitochondrial dynamics via the IRE1α/Xbp1s-Ca2+-associated pathway, which provides a new potential therapeutic approach to SAE.
摘要：
背景：神经炎症在脓毒症相关性脑病（SAE）的病因学基础和动态进展中起关键作用。SAE认知障碍的发生与神经炎症有关。4-苯基丁酸酯（4-PBA）可能通过抑制内质网应激（ERS）来控制炎症。这项研究的主要目的是研究4-PBA在减轻脂多糖（LPS）诱导的神经炎症中的有效性及其对认知功能下降的影响。
方法：建立LPS注射SAE小鼠和LPS处理的BV2细胞和生物体模型作为实验范例，两者都有助于研究的调查框架。认知功能通过行为测试进行评估。使用高尔基体染色和Nissl染色评估海马损伤。定量PCR和免疫荧光分析神经炎症。使用透射电子显微镜检查线粒体功能。蛋白质表达分析是通过应用蛋白质印迹方法进行的，作为在实验框架中阐明分子特征的研究方法。采用流式细胞术检测内质网和线粒体钙流量。为了更深入地研究机械的复杂性，4μ8c的给药用于选择性地阻止IRE1α/Xbp1s途径，构成旨在阐明基本监管过程的战略干预。
结果:当与野生型(WT)对应物相比时,在LPS处理的小鼠的海马组织中,ERS相关蛋白的表达水平表现出显著上调。4-PBA的施用显著改善了LPS处理的小鼠的记忆缺陷。此外，发现4-PBA治疗可减轻氧化应激和神经炎症。机械上,IRE1α/Xbp1s-Ca2+信号通路在介导缓解氧化应激和维持线粒体钙稳态的有益作用中起关键作用，抑制IRE相关途径表现出相反的作用。
结论：我们的结果表明，给予4-PBA治疗可显着减弱ERS，缓解认知能力下降，减少炎症损伤，并通过IRE1α/Xbp1s-Ca2相关途径恢复线粒体动力学，这为SAE提供了一种新的潜在治疗方法。
方法：建立LPS注射SAE小鼠和LPS处理的BV2细胞和生物体模型作为实验范例，两者都有助于研究的调查框架。认知功能通过行为测试进行评估。使用高尔基体染色和Nissl染色评估海马损伤。定量PCR和免疫荧光分析神经炎症。使用透射电子显微镜检查线粒体功能。蛋白质表达分析是通过应用蛋白质印迹方法进行的，作为在实验框架中阐明分子特征的研究方法。采用流式细胞术检测内质网和线粒体钙流量。为了更深入地研究机械的复杂性，4μ8c的给药用于选择性地阻止IRE1α/Xbp1s途径，构成旨在阐明基本监管过程的战略干预。
结果:当与野生型(WT)对应物相比时,在LPS处理的小鼠的海马组织中,ERS相关蛋白的表达水平表现出显著上调。4-PBA的施用显著改善了LPS处理的小鼠的记忆缺陷。此外，发现4-PBA治疗可减轻氧化应激和神经炎症。机械上,IRE1α/Xbp1s-Ca2+信号通路在介导缓解氧化应激和维持线粒体钙稳态的有益作用中起关键作用，抑制IRE相关途径表现出相反的作用。
结论：我们的结果表明，给予4-PBA治疗可显着减弱ERS，缓解认知能力下降，减少炎症损伤，并通过IRE1α/Xbp1s-Ca2相关途径恢复线粒体动力学，这为SAE提供了一种新的潜在治疗方法。
