The Protective Effect of Autophagy on DNA Damage in Mouse Spermatocyte-Derived Cells Exposed to 1800 MHz Radiofrequency Electromagnetic Fields

Cell Physiol Biochem. 2018;48(1):29-41. doi: 10.1159/000491660. Epub 2018 Jul 11.

Abstract

Background/aims: The effects of exposure to radiofrequency electromagnetic fields (RF-EMFs) on the male reproductive system have raised public concern and studies have shown that exposure to RF-EMFs can induce DNA damage and autophagy. However, there are no related reports on the role of autophagy in DNA damage in spermatocytes, especially after exposure to RF-EMFs. The aim of the present study was to determine the mechanism and role of autophagy induced by RF-EMFs in spermatozoa cells.

Methods: Mouse spermatocyte-derived cells (GC-2) were exposed to RF-EMFs 4 W/kg for 24 h. The level of reactive oxygen species (ROS) was determined by ROS assay kit. Comet assay was utilized to detect DNA damage. Autophagy was detected by three indicators: LC3II/LC3I, autophagic vacuoles, and GFP-LC3 dots, which were measured by western blot, transmission electron microscopy, and transfection with GFP-LC3, respectively. The expression of the molecular signaling pathway AMP-activated protein kinase (AMPK)/mTOR was determined by western blot.

Results: The results showed that RF-EMFs induced autophagy and DNA damage in GC-2 cells via ROS generation, and the autophagy signaling pathway AMPK/mTOR was activated by ROS generation. Furthermore, following inhibition of autophagy by knockdown of AMPKα, increased DNA damage was observed in GC-2 cells following RF-EMFs exposure, and overexpression of AMPKα promoted autophagy and attenuated DNA damage.

Conclusions: These findings demonstrated that the autophagy which was induced by RF-EMFs via the AMPK/mTOR signaling pathway could prevent DNA damage in spermatozoa cells.

Keywords: Autophagy; DNA damage; Melatonin; Oxidative stress; Radiofrequency electromagnetic fields.

MeSH terms

  • AMP-Activated Protein Kinases / antagonists & inhibitors
  • AMP-Activated Protein Kinases / genetics
  • AMP-Activated Protein Kinases / metabolism
  • Animals
  • Autophagy / radiation effects*
  • Cell Line
  • Cell Survival / radiation effects
  • Comet Assay
  • DNA Damage / radiation effects*
  • Electromagnetic Fields*
  • Male
  • Mice
  • Microscopy, Electron, Transmission
  • Microtubule-Associated Proteins / metabolism
  • RNA Interference
  • RNA, Small Interfering / metabolism
  • Reactive Oxygen Species / metabolism
  • Signal Transduction / radiation effects
  • Spermatocytes / cytology
  • Spermatocytes / metabolism
  • TOR Serine-Threonine Kinases / metabolism

Substances

  • Map1lc3b protein, mouse
  • Microtubule-Associated Proteins
  • RNA, Small Interfering
  • Reactive Oxygen Species
  • mTOR protein, mouse
  • TOR Serine-Threonine Kinases
  • AMP-Activated Protein Kinases