摘要目的:探究肝X受体（LXR）激动剂GW3965对ATP结合盒转运蛋白（ABC）A1、ABCG1、围脂滴蛋白2（PLIN2）的调节作用及其在幼年小鼠七氟烷暴露后所致认知功能损伤中的作用及机制。方法:无特定病原体（SPF）级C57BL/6雄性小鼠64只，采用随机数字表法分为4组（每组16只）：对照组（Con组）、对照+GW3965组（Con+GW3965组）、七氟烷组（Sev组）、七氟烷+GW3965组（Sev+GW3965组）。Con组、Con+GW3965组小鼠于出生后（PND）第6、8、10天（PND 6、8、10）吸入60%氧气2 h，Sev组、Sev+GW3965组吸入3%七氟烷复合60%氧气2 h。Con+GW3965组及Sev+GW3965小鼠于每日行为学测试前2 h经腹腔注射GW3965 20 mg/kg，Con组及Sev组经腹腔注射等量二甲基亚砜/无菌生理盐水混合液。Morris水迷宫实验分为训练阶段（PND 31~35）和测试阶段（PND 36），用于检测小鼠的逃避潜伏期、目标象限停留时间、平台穿越次数及游泳速度；于PND 36进行旷场实验，检测小鼠中央区探索次数、中央区探索时间、中央区探索距离及探索总距离；于PND 37取小鼠脑组织，采用透射电镜观察海马区脂褐素积累情况，通过逆转录-实时荧光定量聚合酶链式反应（RT-qPCR）检测ABCA1、ABCG1、PLIN2、白细胞介素（IL）-1β、IL-18的信使RNA（mRNA）相对表达量，采用免疫印迹法（Western blot）检测PLIN2水平，采用免疫荧光共定位方法检测小胶质细胞标志物钙结合蛋白1（Iba1）与PLIN2的共标情况。结果:① Morris水迷宫实验结果。在PND 31~35：与Con组比较，Con+GW3965组小鼠逃避潜伏期差异无统计学意义（均 P>0.05），Sev组小鼠逃避潜伏期较长（均 P<0.05）；与Sev组比较，Sev+GW3965组小鼠逃避潜伏期较短（均 P<0.05）。在PND 36：与Con组比较，Con+GW3965组小鼠平台穿越次数、目标象限停留时间差异均无统计学意义（均 P>0.05），Sev组小鼠平台穿越次数较少、目标象限停留时间较短（均 P<0.05）；与Sev组比较，Sev+GW3965组小鼠平台穿越次数较多、目标象限停留时间较长（均 P<0.05）；各组小鼠游泳速度差异无统计学意义（均 P>0.05）。② 旷场实验结果显示，4组小鼠中央区探索次数、中央区探索时间、中央区探索距离及探索总距离差异均无统计学意义（均 P>0.05）。③ 透射电镜结果显示，Sev组观察到明显脂褐素积累，其余3组均未观察到积累的脂褐素。④ RT-qPCR结果。与Con组比较：Con+GW3965组小鼠ABCA1、ABCG1的mRNA相对表达量较高（均 P<0.05），PLIN2、IL-1β、IL-18的mRNA相对表达量差异无统计学意义（均 P>0.05）；Sev组小鼠ABCA1、ABCG1的mRNA相对表达量较低（均 P<0.05），PLIN2、IL-1β、IL-18的mRNA相对表达量较高（均 P<0.05）。与Sev组比较，Sev+GW3965组小鼠ABCA1、ABCG1的mRNA相对表达量较高（均 P<0.05），PLIN2、IL-1β、IL-18的mRNA相对表达量较低（均 P<0.05）。⑤ Western blot结果显示，与Con组比较，Con+GW3965组小鼠PLIN2水平差异无统计学意义（ P>0.05）；Sev组小鼠PLIN2水平较高（ P<0.05）。与Sev组比较，Sev+GW3965组小鼠PLIN2水平较低（ P<0.05）。⑥ 免疫荧光共定位结果显示：与Con组比较，Con+GW3965组小鼠PLIN2和Iba1双阳性细胞比例差异无统计学意义（ P>0.05），Sev组小鼠PLIN2和Iba1双阳性细胞比例较高（ P<0.05）；与Sev组比较，Sev+GW3965组小鼠PLIN2和Iba1双阳性细胞比例较低（ P<0.05）。 结论:GW3965可缓解幼年小鼠七氟烷暴露所致的认知功能损伤，其机制可能与GW3965上调ABCA1、ABCG1表达，从而抑制PLIN2的水平有关。

abstractsObjective:To explore the regulatory effects of the liver X receptor (LXR) agonist GW3965 on ATP-binding cassette transporters (ABC) A1, ABCG1, and perilipin 2 (PLIN2), as well as its role and mechanisms in cognitive dysfunction induced by sevoflurane exposure in juvenile mice.Methods:A total of 64 specific pathogen free male C57BL/6 neonatal mice were selected. According to the random number table method, they were divided into four groups ( n=16): control group (Con group), control+GW3965 group (Con+GW3965 group), sevoflurane group (Sev group), and sevoflurane+GW3965 group (Sev+GW3965 group). Mice in the Con and Con+GW3965 groups were exposed to 60% oxygen for 2 h on postnatal days (PND) 6, 8, and 10. Mice in the Sev and Sev+GW3965 groups were exposed to 3% sevoflurane combined with 60% oxygen for 2 h on the same days. Mice in the Con+GW3965 and Sev+GW3965 groups were intraperitoneally injected with GW3965 at 20 mg/kg one hour prior to behavioral testing, while those in the Con group and Sev group received an equal volume of vehicle through intraperitoneal injection. The Morris water maze test was divided into a training phase (PND 31?35) and a test phase (PND 36) to detect the escape latency, target quadrant residence time, number of platform crossings, and swimming speed of mice. The open field test was performed on PND 36 to measure the number of central zone explorations, central zone exploration time, central zone exploration distance, and total exploration distance. On PND 37, mouse brain tissues were harvested: lipofuscin accumulation in the hippocampus was observed by transmission electron microscopy; the messenger RNA (mRNA) levels of ABCA1, ABCG1, PLIN2, interleukin (IL)-1β, and IL-18 were detected by reverse transcription real-time fluorescent quantitative polymerase chain reaction (RT-qPCR); the expression of PLIN2 protein was measured by Western blot; and the colocalization of the microglial marker ionized calcium-binding adapter molecule 1 (Iba1) and PLIN2 was detected by immunofluorescence colocalization assay. Results:① The results of the Morris water maze test showed that during PND 31?35, compared with the Con group, there was no statistically significant difference in the escape latency of mice in the Con+GW3965 group (all P>0.05), while the escape latency was significantly longer in the Sev group (all P<0.05); compared with the Sev group, the escape latency of mice in the Sev+GW3965 group significantly decreased (all P<0.05). During PND 36, compared with the Con group, there were no statistically significant differences in the number of platform crossings or target quadrant residence time in the Con+GW3965 group (all P>0.05), whereas the Sev group exhibited a significantly reduced number of platform crossings and decreased target quadrant residence time (all P<0.05); compared with the Sev group, the Sev+GW3965 group had a significantly increased number of platform crossings and increased target quadrant residence time (all P<0.05); there was no statistically significant difference in swimming speed among all groups (all P>0.05). ② The results of the open field test showed that there were no statistically significant differences in the number of central zone explorations, central zone exploration time, central zone exploration distance, or total exploration distance among the four groups (all P>0.05). ③ Transmission electron microscopy results revealed obvious lipofuscin accumulation in the Sev group, while no lipofuscin accumulation was observed in the other three groups. ④ The results of RT-qPCR demonstrated that, compared with the Con group, the Con+GW3965 group had significantly increased relative mRNA expression of ABCA1 and ABCG1 (all P<0.05), whereas no statistically significant differences were found in the relative mRNA expression of PLIN2, IL-1β, and IL-18 (all P>0.05); the Sev group exhibited significantly lower relative mRNA expression of ABCA1 and ABCG1 (all P<0.05), and significantly higher relative mRNA expression of PLIN2, IL-1β, and IL-18 (all P<0.05). Compared with the Sev group, the Sev+GW3965 group had significantly increased relative mRNA expression of ABCA1 and ABCG1 (all P<0.05), and significantly decreased relative mRNA expression of PLIN2, IL-1β, and IL-18 (all P<0.05). ⑤ Western blot results revealed that, compared with the Con group, there was no statistically significant difference in PLIN2 protein levels in the Con+GW3965 group ( P>0.05); the levels of PLIN2 protein significantly increased in the Sev group ( P<0.05). Compared with the Sev group, the levels of PLIN2 protein significantly decreased in the Sev+GW3965 group ( P<0.05). ⑥ Immunofluorescence colocalization assay results indicated that compared with the Con group, there was no statistically significant difference in the number of Iba1 and PLIN2 double-positive cells in the Con+GW3965 group ( P>0.05); the number of Iba1 and PLIN2 double-positive cells significantly increased in the Sev group ( P<0.05). Compared with the Sev group, the number of Iba1 and PLIN2 double-positive cells significantly decreased in the Sev+GW3965 group ( P<0.05). Conclusions:GW3965 alleviates cognitive dysfunction induced by isoflurane exposure in juvenile mice, possibly through the upregulation of ABCA1 and ABCG1 expression, which inhibits the level of PLIN2.