Background: When an imbalance occurs between the demand and capacity for protein folding, unfolded proteins accumulate in the endoplasmic reticulum (ER) lumen and activate the unfolded protein response (UPR). In addition, unfolded proteins are cleared from the ER lumen for ubiquitination and subsequent cytosolic proteasomal degradation, which is termed as the ER-associated degradation (ERAD) pathway. This study focused on changes in the UPR and ERAD pathways induced by the repeated inhalation anesthetic exposure in Caenorhabditis elegans./nMethods: Depending on repeated isoflurane exposure, C. elegans was classified into the control or isoflurane group. To evaluate the expression of a specific gene, RNA was extracted from adult worms in each group and real-time polymerase chain reaction was performed. Ubiquitinated protein levels were measured using western blotting, and behavioral changes were evaluated by chemotaxis assay using various mutant strains./nResults: Isoflurane upregulated the expression of ire-1 and pek-1 whereas the expression of atf-6 was unaffected. The expression of both sel-1 and sel-11 was decreased by isoflurane exposure, possibly indicating the inhibition of retro-translocation. The expression of cdc-48.1 and cdc-48.2 was decreased and higher ubiquitinated protein levels were observed in the isoflurane group than in the control, suggesting that deubiquitination and degradation of misfolded proteins were interrupted. The chemotaxis indices of ire-1, pek-1, sel-1, and sel-11 mutants decreased significantly compared to N2, and they were not suppressed further even after the repeated isoflurane exposure./nConclusion: Repeated isoflurane exposure caused significant ER stress in C. elegans. Following the increase in UPR, the ERAD pathway was disrupted by repeated isoflurane exposure and ubiquitinated proteins was accumulated subsequently. UPR and ERAD pathways are potential modifiable neuroprotection targets against anesthesia-induced neurotoxicity.

中文翻译：

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反复接触吸入麻醉剂对秀丽隐杆线虫中未折叠蛋白反应和内质网相关降解的作用

背景：当蛋白质折叠的需求和能力之间发生不平衡时，未折叠蛋白会在内质网 (ER) 腔内积聚并激活未折叠蛋白反应 (UPR)。此外，未折叠蛋白从 ER 腔中清除以进行泛素化和随后的胞质蛋白酶体降解，这被称为 ER 相关降解 (ERAD) 途径。本研究侧重于秀丽隐杆线虫反复吸入麻醉剂暴露引起的 UPR 和 ERAD 通路的变化。/n方法：取决于反复暴露于异氟醚，秀丽隐杆线虫分为对照组或异氟醚组。为了评估特定基因的表达，从每组成虫中提取 RNA 并进行实时聚合酶链反应。使用蛋白质印迹法测量泛素化蛋白质水平，并使用各种突变株通过趋化性测定评估行为变化。/n结果：异氟醚上调ire-1和pek-1的表达，而atf-6的表达不受影响。sel-1和sel-11的表达因异氟醚暴露而降低，可能表明逆向易位受到抑制。cdc-48.1和cdc-48.2的表达在异氟醚组中观察到的泛素化蛋白水平高于对照组，表明去泛素化和错误折叠蛋白的降解被中断。ire-1、pek-1、sel-1和sel-11突变体的趋化性指数与 N2 相比显着降低，并且即使在反复接触异氟醚后它们也没有进一步受到抑制。/n结论：反复接触异氟醚导致显着的 ER线虫中的压力. 随着 UPR 的增加，ERAD 通路被反复接触异氟醚破坏，随后泛素化蛋白质积累。UPR 和 ERAD 通路是针对麻醉诱导的神经毒性的潜在可修改神经保护目标。