Long-term exposure to 4G smartphone radiofrequency electromagnetic radiation diminished male reproductive potential by directly disrupting Spock3–MMP2-BTB axis in the testes of adult rats

https://www.sciencedirect.com/science/article/pii/S0048969719338082?via%3Dihub

Abstract

The correlation between long-term exposure to SRF-EMR and the decline in male fertility is gradually receiving increasing attention from the medical society. While male reproductive organs are often exposed to SRF-EMR, little is currently known about the direct effects of long-term SRF-EMR exposure on the testes and its involvement in the suppression of male reproductive potential. The present study was designed to investigate this issue by using 4G SRF-EMR in rats. A unique exposure model using a 4G smartphone achieved localized exposure to the scrotum of the rats for 6 h each day (the smartphone was kept on active talk mode and received an external call for 1 min over 10 min intervals). Results showed that SRF-EMR exposure for 150 days decreased sperm quality and pup weight, accompanied by testicular injury. However, these adverse effects were not evident in rats exposed to SRF-EMR for 50 days or 100 days. Sequencing analysis and western blotting suggested Spock3 overexpression in the testes of rats exposed to SRF-EMR for 150 days. Inhibition of Spock3 overexpression improved sperm quality decline and alleviated testicular injury and BTB disorder in the exposed rats. Additionally, SRF-EMR exposure suppressed MMP2 activity, while increasing the activity of the MMP14–Spock3 complexes and decreasing MMP14–MMP2 complexes; these results were reversed by Spock3 inhibition. Thus, long-term exposure to 4G SRF-EMR diminished male fertility by directly disrupting the Spock3–MMP2–BTB axis in the testes of adult rats. To our knowledge, this is the first study to show direct toxicity of SRF-EMR on the testes emerging after long-term exposure.

Abbreviations

SRF-EMR smartphone radiofrequency electromagnetic radiation

4G the 4th generation mobile communication technology

Spock3 SPARC/osteonectin, cwcv and kazal like domains proteoglycan 3

BTB blood-testis barrier

MMP2 matrix metallopeptidase 2

MMP14 matrix metallopeptidase 14

Graphical Abstract

From the discussion:
men are advised to keep smartphones away from their testes to avoid potential adverse effects of this neglected low-energy radiation. Given the limitations of this study, additional studies on SRF-EMR with increased exposure duration and different working models of smartphones should be conducted to further confirm the current conclusion along with investigating additional reproductive effects of SRF-EMR. Furthermore, SRF-EMR belongs to RF-EMR, which is emitted by other sources common in daily life such as phone towers and electric substations. Now that the adverse effects of long-term SRF-EMR exposure have been presented, future studies should pay more attention to the long-term health effects of other RF-EMRs with higher energy. These health effects may prove more important in the upcoming 5G era, when more RF-EMRs would be brought into our daily life.”