Qin Li, Luan Zhen-Xian, Li Min, Xiang Ying, Qi Xiao-Rong
Department of Traditional Chinese Medicine, the Sixth Medical Center of PLA General Hospital Beijing 100853, China.
Zhongguo Zhong Yao Za Zhi. 2024 Jun;49(12):3295-3301. doi: 10.19540/j.cnki.cjcmm.20240207.402.
This study aims to reveal the effects of the herb pair Astragali Radix-Salviae Miltiorrhizae Radix et Rhizoma(AR-SMRR) on phosphatidylinositol 3-kinase/protein kinase B/mammalian target of rapamycin(PI3K/Akt/mTOR) pathway and autophagy in the lung tissue of the rat model of acute lung injury(ALI). Fifty adult male SD rats were randomized into sham, model, autophagy inhibition(intraperitoneal injection of chloroquine at 10 mg·kg(-1)), autophagy induction(intraperitoneal injection of rapamycin at 15 mg·kg(-1)), and AR-SMRR(5 g·kg(-1), gavage) groups. The rats in the sham group received intratracheal instillation of normal saline, and those in other groups received intratracheal instillation of lipopolysaccharide(LPS, 5 mg·kg(-1)) for the modeling of ALI. Seven days before the operation, the rats in the sham and model groups were administrated with normal saline, and those in other groups with corresponding drugs. Specimens were collected 24 h after modeling. The pathological changes of the lung tissue were observed under a light microscope. The lung wet/dry weight ratio and the lactate dehydrogenase(LDH) activity and total protein concentration in the bronchoalveolar lavage fluid(BALF) were measured. Western blot was employed to measure the protein levels of microtubule-associated protein 1-light chain 3(LC3), beclin-1, p62, PI3K, Akt, and mTOR. Compared with the sham group, the model group showed increased histopathological score of the lung tissue, lung wet/dry weight ratio, and LDH activity and protein concentration in BALF. Autophagy inhibition further increased these indicators compared with the model group, while autophagy induction and AR-SMRR lowered the levels. In addition, AR-SMRR up-regulated the protein levels of LC3-Ⅱ and beclin-1, down-regulated the expression of p62, and inhibited the expression of p-PI3K, p-Akt, and p-mTOR in the lung tissue of ALI rats. The findings suggest that AR-SMRR can alleviate the lung injury and edema in the rat model of ALI induced by LPS by enhancing autophagy via down-regulating PI3K/Akt/mTOR signaling pathway.
本研究旨在揭示药对黄芪-丹参对急性肺损伤（ALI）大鼠模型肺组织中磷脂酰肌醇3激酶/蛋白激酶B/雷帕霉素哺乳动物靶蛋白（PI3K/Akt/mTOR）信号通路及自噬的影响。将50只成年雄性SD大鼠随机分为假手术组、模型组、自噬抑制组（腹腔注射10 mg·kg⁻¹氯喹）、自噬诱导组（腹腔注射15 mg·kg⁻¹雷帕霉素）和黄芪-丹参组（5 g·kg⁻¹灌胃）。假手术组大鼠气管内滴注生理盐水，其他组大鼠气管内滴注脂多糖（LPS，5 mg·kg⁻¹）以建立ALI模型。术前7天，假手术组和模型组大鼠给予生理盐水，其他组大鼠给予相应药物。造模后24小时采集标本。在光学显微镜下观察肺组织的病理变化。测量肺组织湿/干重比、支气管肺泡灌洗液（BALF）中乳酸脱氢酶（LDH）活性及总蛋白浓度。采用蛋白质免疫印迹法检测微管相关蛋白1轻链3（LC3）、贝林1、p62、PI3K、Akt和mTOR的蛋白水平。与假手术组相比，模型组肺组织病理组织学评分、肺湿/干重比、BALF中LDH活性及蛋白浓度均升高。与模型组相比，自噬抑制进一步增加了这些指标，而自噬诱导和黄芪-丹参组降低了这些指标水平。此外，黄芪-丹参上调了ALI大鼠肺组织中LC3-Ⅱ和贝林1的蛋白水平，下调了p62的表达，并抑制了p-PI3K、p-Akt和p-mTOR的表达。研究结果表明，黄芪-丹参可通过下调PI3K/Akt/mTOR信号通路增强自噬，从而减轻LPS诱导的ALI大鼠模型的肺损伤和肺水肿。
