Objectives: To observe whether electroacupuncture (EA) can inhibit the inflammatory response via down-regulating hexokinase 2 (HK2) mediated Warburg effect in rats with acute lung injury (ALI).
Methods: Male Sprague-Dawley rats were randomly divided into control, model and EA groups, with 12 rats in each group. The ALI model was established by injection of lipopolysaccharides (LPS, 5 mg/mL, 1 mL/kg) into the tail vein. The rats in the control group received intravenous injection of the same volume of 0.9% NaCl solution. Immediately after the modeling was completed, EA (3 Hz/15 Hz, 1 mA) was applied to bilateral "Zusanli" (ST36) and "Chize" (LU5) for 30 min, once a day for 5 consecutive days. The contents of serum interleukin-1β (IL-1β) and transforming growth factor-β (TGF-β) were measured by using the enzyme-linked immunosorbent assay (ELISA), and the wet/dry weight ratio (W/D) of the lung tissue was calculated to assess the severity of pulmonary edema. Histopathological changes of the lung tissue (inflammatory damage, damage score) were observed and calculated after hematoxylin and eosin (H.E.) staining. The qRT-PCR and Western blot were used to detect the expression of HK2 mRNA and protein, respectively. The lactate kit was used to detect the lactate content of the lung tissue.
Results: Compared with the control group, the serum IL-1β content, lung damage score, ratio of W/D of the lung tissue, expression levels of HK2 mRNA and protein and the lactate content were significantly increased (P<0.01), while the serum TGF-β content was significantly decreased (P<0.01) in the model group. In comparison with the model group, the serum IL-1β content, pathological score, HK2 mRNA expression level, and lactic acid content were significantly decreased (P<0.01), and the TGF-β content was significantly increased (P<0.01) in the EA group. H.E. stain showed obvious congestion and hemorrhage of the lung tissue, disappearance of the alveolar structure with thickened alveolar wall, and a large number of inflammatory cells infiltration in the model group, which was relatively milder in the EA group, including milder pulmonary tissue congestion, partial alveolar fusion, and fewer inflammatory cells gathered in the alveolar septum, etc.
Conclusions: EA can reduce the inflammatory response and pulmonary edema of ALI in rats, which may be related to its functions in down-regulating the content of serum IL-1β, and lung HK2 mRNA expression and lactic acid content and in up-regulating serum TGF-β (anti-inflammatory factor) level and HK2-mediated Warburg effect.
目的: 观察电针是否能够通过下调己糖激酶2 （HK2） 介导的有氧糖酵解效应（Warburg效应），抑制大鼠急性肺损伤（ALI）炎性反应。方法: 雄性SD大鼠随机分为对照组、模型组、电针组，每组12只。尾静脉注射脂多糖复制大鼠ALI模型。电针组电针双侧“足三里”和“尺泽”，每次30 min，每日1次，连续治疗5 d。ELISA法检测血清白细胞介素-1β（IL-1β）、转化生长因子-β（TGF-β）含量；计算肺组织湿/干重比值 （W/D）评估肺水肿严重程度；HE染色法观察肺组织细胞的炎性反应损伤并计算损伤评分；实时荧光定量PCR法和Western blot法分别检测肺组织HK2 mRNA及蛋白表达水平；比色法检测肺组织中的乳酸含量。结果: 与对照组比较，模型组血清 IL-1β含量、肺组织W/D升高（P<0.01），血清TGF-β含量降低（P<0.01）；肺组织细胞结构明显被破坏，肺泡壁不完整、变厚断裂，肺泡间质中可见大量炎性细胞浸润及充血，病理损伤评分升高（P<0.01）；肺组织HK2 mRNA及蛋白的表达水平升高（P<0.01），乳酸含量升高（P<0.01）。与模型组比较，电针组血清IL-1β含量降低（P<0.01），TGF-β含量升高（P<0.01）；肺组织细胞结构炎性破坏减少、肺泡壁较完整、肺泡间质中的炎性细胞浸润及红细胞渗出明显减少，病理评分降低（P<0.01）；肺组织HK2 mRNA的表达水平和乳酸含量降低（P<0.01）。结论: 电针可能通过下调HK2介导的Warburg效应，抑制IL-1β等促炎因子的释放及促进TGF-β等抑炎因子的释放，减轻ALI的大鼠炎性反应及肺水肿。.
Keywords: Acute lung injury; Electroacupuncture; Hexokinase 2 (HK2); Warburg effect.