目的

分析紫檀芪（Pterostilbene，PTER）对脓毒症（sepsis）小鼠急性肺损伤（acute lung injury，ALI）的保护作用。

方法

选择SPF 级雄性C57BL/6J 小鼠40 只，6～8 周龄，体质量20～25 g，随机数字表法分对照组（C 组）、PTER 组（P 组）、脂多糖（lipopolysaccharide，LPS）组、LPS＋PTER 组（LPS＋P组），每组10 只。 采用腹腔注射LPS 15 mg/kg 的方法制备脓毒症ALI 小鼠模型，对照组和P 组注射等量生理盐水；LPS＋P 组在注射LPS 后2 h、6 h；P 组在相应时点，于对侧腹腔注射PTER 30 mg/kg。 造模后24 h 深麻醉小鼠，开腹经心尖采血，随后行支气管肺泡灌洗收集支气管肺泡灌洗液（bronchoalveolar lavage fluid，BALF），处死小鼠取肺组织。 采用LEGENDplex 多因子检测试剂盒和PicoGreen dsDNA 定量试剂盒测定小鼠血样白介素-1β（interleukin -1β，L-1β）、IL-6、肿瘤坏死因子-α（tumor necrosis factor，TNF-α）和细胞游离DNA（cell-free DNA，cf-DNA）浓度。 实时荧光定量聚合酶链反应法（quantitative realtime polymerase chain reaction，RT-qPCR）检测小鼠肺组织IL-1β、IL-6、TNF-α mRNA 表达量；苏木精-伊红染色法（ hematoxylin-eosin staining，HE） 染色法观察小鼠肺组织病理学变化，计算肺损伤（lung injury，LI）评分，确定肺湿/干重（wet / dry weight，W/D）比；免疫荧光染色法观察小鼠肺组织中性粒细胞胞外诱捕网（neutrophil extracellular traps，NETs）含量。

结果

与C 组比较，LPS 组小鼠LI 评分、肺W/D 比、BALF 蛋白含量升高（P ＜0.05），血浆IL-1β、IL-6、TNF-α 浓度升高，肺组织IL-1β、IL-6、TNF-α mRNA 表达上调（P＜0.05），血浆cf-DNA、肺组织髓过氧化物酶（myeloperoxidase，MPO）活性及NETs 含量升高；P 组上述指标差异无统计学意义（P＞0.05）。 与LPS 组比较，LPS＋P 组小鼠LI 评分、肺W/D 比、BALF 蛋白含量减低（P＜0.05），血浆IL-1β、IL-6、TNF-α 含量降低，肺组织IL-1β、IL-6、TNF-α mRNA 表达下调（P＜0.05），血浆cf-DNA、肺组织MPO 活性及NETs 含量降低。

结论

PTER 可通过抑制炎症反应和NETs 蓄积减轻脓毒症小鼠ALI。

Objective

To evaluate the protective effect of pterostilbene （PTER） on acute lung injury（ALI） in septic mice.

Methods

Forty SPF-grade male C57BL/6J mice，6-8 weeks old，weighing 20-25 g，were categorized into four groups （n＝10） using a randomized numeric table method：control group （group C），PTER group （group P），LPS group，and LPS＋PTER group （group LPS＋P）.Septic acute lung injury （ALI）model was induced by intraperitoneal injection of LPS 15 mg/kg，with the groups of C and P receiving an equivalent volume of saline.PTER 30 mg/kg were injected in the contralateral peritoneal cavity 2 h and 6 h post-LPS injection in LPS＋P group and at the corresponding time in group P.Mice were anesthetized 24 h after modeling，blood was collected via heart injection，bronchoalveolar lavage fluid （BALF） was obtained through bronchial-alveolar lavage，and lung tissues were harvested post-euthanasia.Mouse blood samples were analyzed for IL-1β，IL-6，TNF-α，and cell-free DNA （cf-DNA）using the LEGENDplex multifactor assay kit，and the PicoGreen dsDNA quantification kit.RT-qPCR was utilized for the assessment of IL-1β，IL-6，and TNF-α mRNA expression in mouse lung tissues.HE staining was conducted to evaluate pathological alterations in mouse lung tissues，with subsequent calculation of lung injury （LI） scores and wet/dry weight （W/D） ratios；immunofluorescence staining was employed to assess the amount of neutrophil extracellular traps （NETs） in mouse lung tissues.

Results

Compared to group C，the LPS group mice exhibited increased LI scores，lung W/D ratios，and BALF protein levels （P＜0.05），as well as upregulated expression of plasma IL-1β，IL-6，and TNF-α proteins，lung tissue IL-1β，IL-6，and TNF-α mRNA （P＜0.05），and elevated plasma cf-DNA，lung tissue myeloperoxidase （MPO） activity and NETs levels.The differences in the above parameters in group P were not statistically significant （P＞0.05）.Compared to LPS group，group LPS＋P mice displayed decreased LI scores，lung W/D ratios，and BALF protein concentrations （P＜0.05），along with downregulated plasma IL-1β，IL-6，TNF-α levels，lung tissue IL-1β，IL-6，TNF-α mRNA expression （P＜0.05），and reduced plasma cf-DNA，lung tissue MPO activity and NETs levels.

Conclusion

PTER ameliorates ALI in septic mice by inhibiting inflammatory responses and NETs accumulation.