Zhenxing Wang1, Yongcan Wu1, Caixia Pei1, Mingjie Wang1, Xiaomin Wang1, Shihua Shi1, Demei Huang1, Yilan Wang1, Shuiqin Li1, Wei Xiao1, Yacong He2, Fei Wang3. 1. Hospital of Chengdu University of Traditional Chinese Medicine, No. 39 Shi-er-qiao Road, Chengdu, Sichuan 610075, China. 2. School of Pharmacy, Chengdu University of Traditional Chinese Medicine, No.1166 Liutai Avenue, Chengdu, Sichuan 611137, China. Electronic address: heyacong@126.com. 3. Hospital of Chengdu University of Traditional Chinese Medicine, No. 39 Shi-er-qiao Road, Chengdu, Sichuan 610075, China. Electronic address: wangfei896@163.com.
Abstract
BACKGROUND: Fine particulate matter (PM2.5) with an aerodynamic diameter of less than 2.5 μm, exerts serious lung toxicity. At present, effective prevention measures and treatment modalities for pulmonary toxicity caused by PM2.5 are lacking. Astragaloside IV (AS-IV) is a natural product that has received increasing attention from researchers for its unique biological functions. PURPOSE: To investigate the protective effects of AS-IV on PM2.5-induced pulmonary toxicity and identify its potential mechanisms. METHODS: The rat model of PM2.5-induced lung toxicity was created by intratracheal instillation of PM2.5 dust suspension. The investigation was performed with AS-IV or in combination with autophagic flux inhibitor (Chloroquine) or AMP-sensitive protein kinase (AMPK)-specific inhibitor (Compound C). Apoptosis was detected by terminal deoxy-nucleotidyl transferase dUTP nick end labeling (TUNEL) and western blotting. Autophagy was detected by immunofluorescence staining, autophagic flux measurement, western blotting, and transmission electron microscopy. The AMPK/mTOR pathway was analyzed by western blotting. Inflammation was analyzed by western blotting and suspension array. RESULTS: AS-IV prevented histopathological injury, inflammation, autophagy dysfunction, apoptosis, and changes in AMPK levels induced by PM2.5. AS-IV increased autophagic flux and inhibited apoptosis and inflammation by activating the AMPK/ mammalian target of rapamycin (mTOR) pathway. However, AS-IV had no protective effect on PM2.5-induced lung injury following treatment with Compound C or Chloroquine. CONCLUSION: AS-IV prevented PM2.5-induced lung toxicity by restoring the balance among autophagy, apoptosis, and inflammation in rats by activating the AMPK/mTOR signaling pathway.
BACKGROUND: Fine particulate matter (PM2.5) with an aerodynamic diameter of less than 2.5 μm, exerts serious lung toxicity. At present, effective prevention measures and treatment modalities for pulmonary toxicity caused by PM2.5 are lacking. Astragaloside IV (AS-IV) is a natural product that has received increasing attention from researchers for its unique biological functions. PURPOSE: To investigate the protective effects of AS-IV on PM2.5-induced pulmonary toxicity and identify its potential mechanisms. METHODS: The rat model of PM2.5-induced lung toxicity was created by intratracheal instillation of PM2.5 dust suspension. The investigation was performed with AS-IV or in combination with autophagic flux inhibitor (Chloroquine) or AMP-sensitive protein kinase (AMPK)-specific inhibitor (Compound C). Apoptosis was detected by terminal deoxy-nucleotidyl transferase dUTP nick end labeling (TUNEL) and western blotting. Autophagy was detected by immunofluorescence staining, autophagic flux measurement, western blotting, and transmission electron microscopy. The AMPK/mTOR pathway was analyzed by western blotting. Inflammation was analyzed by western blotting and suspension array. RESULTS: AS-IV prevented histopathological injury, inflammation, autophagy dysfunction, apoptosis, and changes in AMPK levels induced by PM2.5. AS-IV increased autophagic flux and inhibited apoptosis and inflammation by activating the AMPK/ mammalian target of rapamycin (mTOR) pathway. However, AS-IV had no protective effect on PM2.5-induced lung injury following treatment with Compound C or Chloroquine. CONCLUSION: AS-IV prevented PM2.5-induced lung toxicity by restoring the balance among autophagy, apoptosis, and inflammation in rats by activating the AMPK/mTOR signaling pathway.