Division of Molecular Medicine, SickKids Research Institute, Toronto, Canada.
Department of Anesthesia and Pain Medicine, Hospital for Sick Children, 555 University Ave., Toronto, ON, M5G 1X8, Canada.
Sci Rep. 2021 Mar 11;11(1):5673. doi: 10.1038/s41598-021-85125-5.
The potential adverse impact of inhalational anesthetics on the developing brain was highlighted by the addition of a medication warning by the U.S. Food and Drug Administration for their use in the pediatric population. To investigate mechanisms by which early life anesthesia exposure could induce long-term neuronal dysfunction, we exposed rats to 1 minimum alveolar concentration sevoflurane at 7 days of life. The animals were raised normally until adulthood (P300) prior to sacrifice and analysis of cortical tissue structure (TEM), mitochondrial quality control and biogenesis pathways (Western blot, ELISA, ADP/ATP content), and markers of oxidative stress, proteotoxicity and inflammation (Western blot, ELISA). We found that early life anesthesia exposure led to adverse changes in mitochondrial quality maintenance pathways, autophagy and mitochondrial biogenesis. Although there was an escalation of oxidative stress markers and an increase in the nuclear localization of stress-related transcription factors, cellular redox compensatory responses were blunted, and oxidative phosphorylation was reduced. We found upregulation of mitochondrial stress and proteotoxicity markers, but a significant reduction of mitochondrial unfolded protein response end-effectors, contributing to an increase in inflammation. Contrary to acute exposure, we did not find an increase in apoptosis. Our findings suggest that a limited, early exposure to anesthesia may produce lasting cellular dysfunction through the induction of a sustained energy deficient state, resulting in persistent neuroinflammation and altered proteostasis/toxicity, mimicking aspects of chronic neurodegenerative diseases.
吸入麻醉剂对发育中大脑的潜在不良影响,通过美国食品和药物管理局在儿科人群中使用吸入麻醉剂时添加药物警告而凸显出来。为了研究幼年麻醉暴露可能通过何种机制诱导长期神经元功能障碍,我们在 7 天大的幼鼠中用 1 个最低肺泡有效浓度的七氟醚进行麻醉。动物正常生长至成年期(P300)后处死,分析皮质组织结构(透射电镜)、线粒体质量控制和生物发生途径(Western blot、ELISA、ADP/ATP 含量)以及氧化应激、蛋白毒性和炎症标志物(Western blot、ELISA)。我们发现幼年麻醉暴露导致线粒体质量维持途径、自噬和线粒体生物发生的不良变化。虽然氧化应激标志物的增加和应激相关转录因子的核定位增加,但细胞氧化还原补偿反应减弱,氧化磷酸化减少。我们发现线粒体应激和蛋白毒性标志物的上调,但线粒体未折叠蛋白反应终效器显著减少,导致炎症增加。与急性暴露相反,我们没有发现细胞凋亡增加。我们的研究结果表明,有限的早期麻醉暴露可能通过诱导持续的能量不足状态产生持久的细胞功能障碍,导致持续的神经炎症和蛋白质稳态/毒性改变,模拟慢性神经退行性疾病的某些方面。