Objective: To observe the effect of electroacupuncture (EA) pretreatment on inflammatory response in ven-tilator-induced lung injury (VILI) mice, so as to explore the underlying mechanism of EA pretreatment on prevention of VILI.
Methods: C57BL/6 mice were randomly divided into sham-operation group, model group, EA group and sham-acupoint group，with 8 mice in each group. The VILI model was established by ventilation with high tidal volume. Mice in the EA group and sham-acupoint group were given EA at "Zusanli" (ST36)and "Feishu"(BL13) or non-acupoints (located at 1-2 cm on both sides of the tail root of the proximal trunk) before mechanical ventilation, 30 min each time, once a day for 5 days. Arterial blood was collec-ted for blood gas analysis, the total protein content in bronchoalveolar lavage fluid (BALF) was detected by BCA method. The contents of interleukin-1β (IL-1β) and interleukin-18 (IL-18) in BALF were detected by ELISA. Lung injury score was determined after HE staining. The protein expression levels of nucleotide-binding oligomerization domain-like receptor protein 3(NLRP3), apoptosis-associated speck-like protein containing a caspase-recruitment domain (ASC) and Caspase-1 in lung tissue was detected by Western blot.
Results: Compared with the sham-operation group, the arterial partial pressure of oxygen and oxygenation index were decreased(P<0.05), the levels of total protein, IL-1β and IL-18 in BALF, the W/D value and the pathological injury score of lung tissue and the protein expression levels of NLRP3, Caspase-1 and ASC were increased(P<0.05)in the model group. Following the interventions, the above mentioned increased or decreased indicators were reversed(P<0.05) in the EA group rather than in the sham-acupoint group.
Conclusion: EA pretreatment of ST36 and BL13 can reduce the damage of lung tissue caused by mechanical ventilation, which may be related to its effect in reducing the expression of NLPR3 inflammasome related proteins, reducing the activation of inflammasome, and thereby reducing the inflammatory response.
目的：探讨电针预处理对呼吸机相关性肺损伤(VILI)小鼠炎性反应及核苷酸结合寡聚化结构域样受体蛋白3(NLRP3)炎性小体的影响。方法：C57BL/6小鼠随机分为假手术组、模型组、电针组及非经非穴组，每组8只。采用高潮气量机械通气建立VILI小鼠模型。电针组和非经非穴组于机械通气前电针“足三里”“肺俞”或非经非穴点，每次30 min，每日1次，治疗5 d。采集动脉血行血气分析，采用BCA法检测支气管肺泡灌洗液(BALF)中总蛋白含量，采用ELISA法检测 BALF 中白细胞介素(IL)-1β和IL-18含量，计算肺组织湿干重比(W/D)，HE染色观察肺组织病理情况并评定肺组织损伤评分，Western blot法检测肺组织中NLRP3、凋亡相关斑点样蛋白(ASC)、半胱氨酸天冬氨酸水解酶-1(Caspase-1)蛋白表达水平。结果：与假手术组相比，模型组小鼠动脉血氧分压(PaO2)、氧合指数(OI)降低(P<0.05)，BALF中总蛋白、IL-1β和IL-18含量升高(P<0.05)，W/D及肺组织病理损伤评分升高(P<0.05)，肺组织NLRP3、Caspase-1与ASC蛋白表达水平升高(P<0.05)。与模型组相比，电针组PaO2、OI升高(P<0.05)，BALF中总蛋白、IL-1β和IL-18含量降低(P<0.05)，W/D及肺组织病理损伤评分降低(P<0.05)，肺组织NLRP3、Caspase-1与ASC蛋白表达水平降低(P<0.05)。结论：电针预处理可以减轻高潮气量机械通气引起的肺组织结构破坏，改善肺组织氧合功能，减轻炎性反应，其机制可能与降低肺组织NLPR3炎性小体相关蛋白的表达，减少炎性小体活化，从而减轻炎性反应有关。.
Keywords: Electroacupuncture pretreatment; NLRP3 inflammasome；Inflammatory reaction; Ventilator-induced lung injury.