Renyan Li1, Mingfu Ma1, Lianbing Li1, Letian Zhao1, Tianfeng Zhang1, Xiaohan Gao1, Danyan Zhang1, Yijian Zhu1, Qiang Peng2, Xue Luo3, Minglian Wang4. 1. Chongqing Population and Family Planning Science and Technology Research Institute, Key Lab of Birth Defects and Reproductive Health of National Health and Family Planning Commission, Chongqing, China. 2. Beibei District of Chongqing Municipal Public Security Bureau of Interpol detachment, Chongqing, China. 3. Department of Tropical Medicine, College of Military Preventive Medicine, Army Medical University, Chongqing, China. 4. College of Life Science and Bioengineering, Beijing University of Technology, Chaoyang District, Beijing, China.
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.
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.