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摘要：
目的 探究七氟醚后处理对脑缺血/再灌注（ischemia/reperfusion, I/R）损伤大鼠的脑保护作用及对活性氧（reactive oxygen species, ROS）/硫氧还蛋白结合蛋白（thioredoxin interacting protein, TXNIP）/NOD样受体相关蛋白3（NOD‑like receptor associated protein 3, NLRP3）信号通路的影响。 方法 60只SD雄性大鼠按随机数字表法分为假手术组（sham组）、I/R组、七氟醚后处理组（SP组），每组20只。采用大脑中动脉线栓法制备脑I/R模型，SP组造模后即刻吸入2.4%七氟醚30 min。对各组大鼠进行神经功能缺损评分；获取大鼠脑组织，H‑E染色和2，3，5‑氯化三苯基四氮唑（2, 3, 5‑triphenyltetrazolium chloride, TTC）染色观察组织病理学变化和脑梗死体积；分析大鼠脑水肿程度及血脑屏障通透性；TUNEL法检测脑组织细胞凋亡率；检测血清炎性因子（IL‑1β和IL‑18）及脑组织氧化应激指标［ROS、丙二醛（malondialdehyde, MDA）、超氧化物歧化酶（superoxide dismutase, SOD）和谷胱甘肽过氧化物酶（glutathione peroxidase, GPx）］的水平；Western blot法检测TXNIP/NLRP3通路相关蛋白［TXNIP、NLRP3、凋亡相关点样蛋白（apotosis‑associated speck‑like protein containing a CARD, ASC）、半胱氨酸天冬氨酸酶‑1（cysteine aspartase, caspase‑1）］的表达。 结果 与sham组比较，I/R组大鼠神经功能缺损评分、脑梗死体积明显升高（P<0.05），脑组织水肿程度及血脑屏障通透性也明显增加，脑细胞凋亡率升高（P<0.05），血清IL‑1β和IL‑18含量明显升高（P<0.05），脑组织中ROS和MDA含量及TXNIP、NLRP3、ASC和caspase‑1蛋白表达水平均明显升高（P<0.05），而GPx和SOD活性降低（P<0.05）；与I/R组比较，SP组神经功能缺损评分和脑梗死体积降低（P<0.05），脑水肿程度及血脑屏障通透性下降，脑细胞的凋亡率降低（P<0.05），血清IL‑1β和IL‑18含量明显降低（P<0.05），脑组织中ROS和MDA含量及TXNIP、NLRP3、ASC和caspase‑1蛋白水平明显降低（P<0.05），而GPx和SOD活性升高（P<0.05）。 结论 七氟醚后处理能够有效减轻大鼠脑I/R损伤，可能与其对ROS/TXNIP/NLRP3信号通路的抑制有关。
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Abstract: Objective To explore the protective effects of sevoflurane postconditioning on cerebral ischemia/reperfusion(I/R) injury in rats and its effect on the reactive oxygen species (ROS)/thioredoxin interacting protein (TXNIP)/NOD‑like receptor‑associated protein3 (NLRP3) signaling pathway. Methods According to the random number table method, a total of 60 male SD rats were divided into three groups (n=20): a sham operation (sham) group, an I/R group and a sevoflurane postconditioning (SP) group. A model of cerebral I/R was established through middle cerebral artery suture, and the SP group inhaled 2.4% sevoflurane over 30 min immediately after modeling. Their neurological deficit scores were evaluated. The brain tissues were obtained and the histopathological changes and cerebral infarction volume were observed by hematoxylin‑eosin (H‑E) staining and 2, 3, 5‑triphenyltetrazolium chloride (TTC) staining. The degree of brain edema and blood‑brain barrier permeability in rats were analyzed. The apoptosis rate of brain tissue cells were detected by terminal‑deoxynucleoitidyl transferase mediated nick end labeling (TUNEL) method. The levels of serum inflammatory factors, such as interleukin (IL)‑1β and IL‑18, and oxidative stress indicators of brain tissues, such as ROS, malondialdehyde (MDA), superoxide dismutase (SOD) and glutathione peroxidase (GPx) were detected. The expression of TXNIP/NLRP3 pathway related proteins, such as TXNIP, NLRP3, apoptosis‑associated speck‑like protein containing a CARD (ASC), and cysteine aspartase (caspase‑1) were detected by Western blot. Results Compared with the sham group, the I/R group presented remarkable increases in neurological deficit score and cerebral infarction volume (P<0.05), the degree of brain edema and the permeability of blood‑brain barrier, the apoptotic rate of brain cells (P<0.05), the levels of serum IL‑1β and IL‑18, the contents of ROS and MDA in brain tissues, and the levels of TXNIP, NLRP3, ASC and caspase‑1 protein, as well as decreases in the activities of GPx and SOD (P<0.05). Compared with the I/R group, the SP group presented remarkable decreases in neurological deficit score and cerebral infarction volume (P<0.05), the degree of brain edema and the permeability of blood‑brain barrier, the apoptotic rate of brain cells (P<0.05), the levels of serum IL‑1β and IL‑18, the contents of ROS and MDA in brain tissues, and the levels of TXNIP, NLRP3, ASC and caspase‑1 protein, as well as increases in the activities of GPx and SOD (P<0.05). Conclusions Sevoflurane postconditioning can effectively relieve cerebral I/R injury in rats, which may be related to the inhibition of the ROS/TXNIP/NLRP3 signaling pathway.
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