Salidroside regulates inflammatory pathway of alveolar macrophages by influencing the secretion of miRNA-146a exosomes by lung epithelial cells

Sci Rep. 2020 Nov 27;10(1):20750. doi: 10.1038/s41598-020-77448-6.

Abstract

The purpose of this study was to explore the investigative mechanism of salidroside (SAL) on LPS-induced acute lung injury (ALI)/acute respiratory distress syndrome (ARDS). The exosomes from RLE-6TN are extracted and identified by transmission electron microscopy, particle size analysis and protein marker detection, and co-cultured with NR8383 cells. The ALI/ARDS model of SD rats was established by LPS (10 mg/kg) intratracheal instillation. Following a four-hour intratracheal instillation of LPS, 50 μl of RLE-6TN exosomes were injected through the tail vein. After that, SAL and miR-146a antagomir were injected into the tail vein for 72 h, respectively. As the changes of HE stain, body weight and ALI score are observed. The expression of miR-146a, TLR4, NF-kB, IRAK1, TRAF6 and their related proteins were detected by RT-PCR and Western blot, respectively. TNF-α, IL-6, IL-8 and IL-1 β inflammatory factors were detected by ELISA. The expression of miR-146a, NF-kB, IRAK, TRAF6 and related inflammatory factors in LPS-induced NR8383 was significantly higher than that in the control group, while SAL has greatly reduced the expression of TLR4 mediated NF-kB inflammatory pathway and related inflammatory factors. SAL can significantly improve the LPS-induced lung morphological abnormalities, slowed down the rate of weight loss in rats, and reducing the ALI score. The expression trend of NF-kB, IRAK, TRAF6 and related inflammatory factors in rats' lung tissues was consistent with that in NR8383 cells. SAL has a protective effect on ALI/ARDS caused by sepsis, which is likely to be developed to a potential treatment for the disease. To sum up, this study provides a new theoretical basis for the treatment of ALI/ARDS with SAL.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Acute Lung Injury / drug therapy
  • Acute Lung Injury / metabolism*
  • Acute Lung Injury / pathology
  • Animals
  • Coculture Techniques
  • Disease Models, Animal
  • Epithelial Cells / drug effects
  • Epithelial Cells / metabolism*
  • Exosomes / drug effects
  • Exosomes / genetics
  • Exosomes / metabolism*
  • Glucosides / pharmacology*
  • Inflammation / drug therapy
  • Inflammation / metabolism*
  • Inflammation / pathology
  • Macrophages, Alveolar / metabolism*
  • Male
  • MicroRNAs / genetics*
  • Phenols / pharmacology*
  • Rats
  • Rats, Sprague-Dawley
  • Signal Transduction

Substances

  • Glucosides
  • MIRN146a microRNA, rat
  • MicroRNAs
  • Phenols
  • rhodioloside