Journal of electromagnetic engineering and science

The Korean Institute of Electromagnetic Engineering and Science (한국전자파학회)
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Endonuclease G is Upregulated and Required in Testicular Germ Cell Apoptosis after Exposure to 60 Hz at 200 μT

  • Park, Sungman (Institute of Medical Science, School of Medicine, Hallym University) ;
  • Kim, Min-Woo (Department of Microbiology, School of Medicine, Hallym University) ;
  • Kim, Ji-Hoon (Institute of Medical Science, School of Medicine, Hallym University) ;
  • Lee, Yena (Institute of Medical Science, School of Medicine, Hallym University) ;
  • Kim, Min Soo (Institute of Medical Science, School of Medicine, Hallym University) ;
  • Lee, Yong-Jun (Institute of Medical Science, School of Medicine, Hallym University) ;
  • Kim, Young-Jin (Institute of Medical Science, School of Medicine, Hallym University) ;
  • Kim, Hee-Sung (Institute of Medical Science, School of Medicine, Hallym University) ;
  • Kim, Yoon-Won (Institute of Medical Science, School of Medicine, Hallym University)
  • Received : 2015.05.11
  • Accepted : 2015.07.07
  • Published : 2015.07.31
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Abstract

Several reports supported that continuous exposure to 60 Hz magnetic field (MF) induces testicular germ cell apoptosis in vivo. We recently evaluated duration- and dose-dependent effects of continuous exposure to a 60 Hz MF on the testes in mice. BALB/c male mice were exposed to a 60 Hz MF at $100{\mu}T$ for 24 hours a day for 2, 4, 6, or 8 weeks, and at 2, 20 or $200{\mu}T$ for 24 hours a day for 8 weeks. To induce the apoptosis of testicular germ cell in mice, the minimum dose is $20{\mu}T$ at continuous exposure to a 60 Hz MF for 8 weeks, and the minimum duration is 6 weeks at continuous exposure of $100{\mu}T$. Continuous exposure to a 60 Hz MF might affect duration- and dose-dependent biological processes including apoptotic cell death and spermatogenesis in the male reproductive system of mice. The safety guideline of the International Commission on Non-Ionizing Radiation Protection (ICNIRP) indicates that the permissible maximum magnetic flux density for general public exposure is $200{\mu}T$ at 60 Hz EMF (ICNIRP Guidelines, 2010). In the present study, we aimed to examine the expression of pro- and anti-apoptotic genes regulated by the continuous exposure to 60 Hz at $200{\mu}T$ in Sprague-Dawley rats for 20 weeks. The continuous exposure to 60 Hz at $200{\mu}T$ does not affect the body and testicular weight in rats. However, exposure to 60 Hz MF significantly affects testicular germ cell apoptosis and sperm count. Further, the apoptosis-related gene was scrutinized after exposure to 60 Hz at $200{\mu}T$ for 20 weeks. We found that the message level of endonuclease G (EndoG) was greatly increased following the exposure to 60 Hz at $200{\mu}T$ compared with sham control. These data suggested that 60 Hz magnetic field induced testicular germ cell apoptosis through mitochondrial protein Endo G.

Keywords

References

  1. M. H. Repacholi, "Introduction to non-ionizing radiations," in Non-Ionizing Radiation: Proceedings of the 3rd International Non-Ionizing Radiation Workshop, Oberschleissheim, Germany: International Commission on Non-Ionizing Radiation Protection, 1996.
  2. International Commission on Non-Ionizing Radiation Protection, "Guidelines for limiting exposure to time-varying electric and magnetic fields (1 Hz to 100 kHz)," Health Physics, vol. 99, no. 6, pp. 818-836, 2010. https://doi.org/10.1097/HP.0b013e3181f06c86
  3. N. H. Hjollund, J. H. Skotte, H. A. Kolstad, and J. P. Bonde, "Extremely low frequency magnetic fields and fertility: a follow up study of couples planning first pregnancies," Occupational and Environmental Medicine, vol. 56, no. 4, pp. 253-255, 1999. https://doi.org/10.1136/oem.56.4.253
  4. H. Huuskonen, J. Juutilainen, A. Julkunen, J. Maki-Paakkanen, and H. Komulainen, "Effects of low-frequency magnetic fields on fetal development in CBA/Ca mice," Bioelectromagnetics, vol. 19, no. 8, pp. 477-485, 1998. https://doi.org/10.1002/(SICI)1521-186X(1998)19:8<477::AID-BEM5>3.0.CO;2-L
  5. M. A. Al-Akhras, A. Elbetieha, M. K. Hasan, I. Al-Omari, H. Darmani, and B. Albiss, "Effects of extremely low frequency magnetic field on fertility of adult male and female rats," Bioelectromagnetics, vol. 22, no. 5, pp. 340-344, 2001. https://doi.org/10.1002/bem.59
  6. Y. W. Kim, J. S. Lee, I. E. Jang, Y. H. Choi, S. H. Kang, K. C. Jung, Y. M. Gimm, and M. G. Cho, "Effects of continuous exposure of 60 Hz magnetic fields on the mice through the third-generation," Journal of Korea Institute of Electronics Engineers, vol. 28, no. 2, pp. 90-104, 2001.
  7. A. Elbetieha, M. A. Al-Akhras, and H. Darmani, "Long-term exposure of male and female mice to 50 Hz magnetic field: effects on fertility," Bioelectromagnetics, vol. 23, no. 2, pp. 168-172, 2002. https://doi.org/10.1002/bem.109
  8. T. Negishi, S. Imai, M. Itabashi, I. Nishimura, and T. Sasano, "Studies of 50 Hz circularly polarized magnetic fields of up to 350 microT on reproduction and embryofetal development in rats: exposure during organogenesis or during preimplantation," Bioelectromagnetics, vol. 23, no. 5, pp. 369-389, 2002. https://doi.org/10.1002/bem.10025
  9. R. De Vita, D. Cavallo, L. Raganella, P. Eleuteri, M. G. Grollino, and A. Calugi, "Effects of 50 Hz magnetic fields on mouse spermatogenesis monitored by flow cytometric analysis," Bioelectromagnetics, vol. 16, no. 5, pp. 330-334, 1995. https://doi.org/10.1002/bem.2250160510
  10. C. I. Kowalczuk, L. Robbins, J. M. Thomas, and R. D. Saunders, "Dominant lethal studies in male mice after exposure to a 50 Hz magnetic field," Mutation Research, vol. 328, no. 2, pp. 229-237, 1995. https://doi.org/10.1016/0027-5107(95)00012-8
  11. J. S. Lee, S. S. Ahn, K. C. Jung, Y. W. Kim, and S. K. Lee, "Effects of 60 Hz electromagnetic field exposure on testicular germ cell apoptosis in mice," Asian Journal of Andrology, vol. 6, no. 1, pp. 29-34, 2004.
  12. Y. W. Kim, H. S. Kim, J. S. Lee, Y. J. Kim, S. K. Lee, J. N. Seo, K. C. Jung, N. Kim, and Y. M. Gimm, "Effects of 60 Hz 14 ${\mu}T$ magnetic field on the apoptosis of testicular germ cell in mice," Bioelectromagnetics, vol. 30, no. 1, pp. 66-72, 2009. https://doi.org/10.1002/bem.20448
  13. R. Hong, Y. Liu, Y. M. Yu, K. Hu, and E. Q. Weng, "Effects of extremely low frequency electromagnetic fields on male reproduction in mice," Zhonghua Lao Dong Wei Sheng Zhi Ye Bing Za Zhi, vol. 21, no. 5, pp. 342-345, 2003.
  14. I. F. Ozguner, H. Dindar, A. Yagmurlu, C. Savas, I. H. Gokcora, and S. Yucesan, "The effect of electromagnetic field on undescended testis after orchiopexy," International Urology and Nephrology, vol. 33, no. 1, pp. 87-93, 2002. https://doi.org/10.1023/A:1014473407519
  15. M. A. Al-Akhras, H. Darmani, and A. Elbetieha, "Influence of 50 Hz magnetic field on sex hormones and other fertility parameters of adult male rats," Bioelectromagnetics, vol. 27, no. 2, pp. 127-131, 2006. https://doi.org/10.1002/bem.20186
  16. R. Hong, Y. Zhang, Y. Liu, and E. Q. Weng, "Effects of extremely low frequency electromagnetic fields on DNA of testicular cells and sperm chromatin structure in mice," Zhonghua Lao Dong Wei Sheng Zhi Ye Bing Za Zhi, vol. 23, no. 6, pp. 414-417, 2005.
  17. J. A. Heredia-Rojas, D. E. Caballero-Hernandez, A. O. Rodriguez-de la Fuente, G. Ramos-Alfano, and L. E. Rodriguez-Flores, "Lack of alterations on meiotic chromosomes and morphological characteristics of male germ cells in mice exposed to a 60 Hz and 2.0 mT magnetic field," Bioelectromagnetics, vol. 25, no. 1, pp. 63-68, 2004. https://doi.org/10.1002/bem.10184
  18. M. K. Chung, S. J. Lee, Y. B. Kim, S. C. Park, D. H. Shin, S. H. Kim, and J. C. Kim, "Evaluation of spermatogenesis and fertility in F1 male rats after in utero and neonatal exposure to extremely low frequency electromagnetic fields," Asian Journal of Andrology, vol. 7, no. 2, pp. 189-194, 2005. https://doi.org/10.1111/j.1745-7262.2005.00007.x
  19. M. A. Al-Akhras, "Influence of 50 Hz magnetic field on sex hormones and body, uterine, and ovarian weights of adult female rats," Electromagnetic Biology and Medicine, vol. 27, no. 2, pp. 155-163, 2008. https://doi.org/10.1080/15368370802072125
  20. L. A. Ramadan, A. Abd-Allah, H. Aly, and A. Saad-eldin, "Testicular toxicity effects of magnetic field exposure and prophylactic role of coenzyme Q10 and L-carnitine in mice," Pharmacological Research, vol. 46, no. 4, pp. 363-370, 2002. https://doi.org/10.1016/S1043661802001718
  21. B. M. Tenorio, G. C. Jimenez, R. N. Morais, S. M. Torres, R. A. Nogueira, and V. A. Silva Junior, "Testicular development evaluation in rats exposed to 60 Hz and 1 mT electromagnetic field," Journal of Applied Toxicology, vol. 31, no. 3, pp. 223-230, 2011. https://doi.org/10.1002/jat.1584
  22. B. M. Tenorio, G. C. Jimenez, R. N. Morais, C. A. Peixoto, R. Albuquerque Nogueira, and V. A. Silva, "Evaluation of testicular degeneration induced by low-frequency electromagnetic fields," Journal of Applied Toxicology, vol. 32, no. 3, pp. 210-218, 2012. https://doi.org/10.1002/jat.1680
  23. H. S. Kim, B. J. Park, H. J. Jang, N. S. Ipper, S. H. Kim, Y. J. Kim, S. H. Jeon, K. S. Lee, S. K. Lee, N. Kim, Y. J. Ju, Y. M. Gimm, and Y. W. Kim, "Continuous exposure to 60 Hz magnetic fields induces duration and dose dependent apoptosis of testicular germ cells, "Bioelectromagnetics, vol. 35, no. 2, pp. 100-107, 2014. https://doi.org/10.1002/bem.21819
  24. S. Elmore, "Apoptosis: a review of programmed cell death," Toxicologic Pathology, vol. 35, no. 4, pp. 495-516, 2007. https://doi.org/10.1080/01926230701320337
  25. C. Shaha, R. Tripathi, and D. P. Mishra, "Male germ cell apoptosis: regulation and biology," Philosophical Transactions B, vol. 365, no. 1546, pp. 1501-1515, 2010. https://doi.org/10.1098/rstb.2009.0124
  26. E. B. Rucker III, P. Dierisseau, K. U. Wagner, L. Garrett, A. Wynshaw-Boris, J. A. Flaws, and L. Hennighausen, "Bcl-x and Bax regulate mouse primordial germ cell survival and apoptosis during embryogenesis," Molecular Endocrinology, vol. 14, no. 7, pp. 1038-1052, 2000. https://doi.org/10.1210/mend.14.7.0465
  27. T. Fruchi, K. Masuko, Y. Nishimune, M. Obinata, and Y. Matsui, "Inhibition of testicular germ cell apoptosis and differentiation in mice misexpressing Bcl-2 in spermatogonia," Development, vol. 122, no. 6, pp. 1703-1709, 1996.
  28. C. M. Knudson, K. S. Tung, W. G. Tourtellotte, G. A. Brown, and S. J. Korsmeyer, "Bax-deficient mice with lymphoid hyperplasia and male germ cell death," Science, vol. 270, no. 5233, pp. 96-99, 1995. https://doi.org/10.1126/science.270.5233.96
  29. T. L. Beumer, H. L. Roepers-Gajadien, I. S. Gademan, P. P. van Buul, G. Gil-Gomez, D. H. Rutgers, and D. G. de Rooij, "The role of the tumor suppressor p53 in spermatogenesis," Cell Death and Differentiation, vol. 5, no. 8, pp. 669-677, 1998. https://doi.org/10.1038/sj.cdd.4400396
  30. V. Tiranti, E. Rossi, A. Ruiz-Carrillo, G. Rossi, M. Rocchi, S. DiDonato, O. Zuffardi, and M. Zeviani, "Chromosomal localization of mitochondrial transcription factor A (TCF6), single-stranded DNA-binding protein (SSBP), and endonuclease G (ENDOG), three human housekeeping genes involved in mitochondrial biogenesis," Genomics, vol. 25, no. 2, pp. 559-564, 1995. https://doi.org/10.1016/0888-7543(95)80058-T
  31. L. Y. Li, X. Luo, and X. Wang, "Endonuclease G is an apoptotic DNase when released from mitochondria," Nature, vol. 412, no. 6842, pp. 95-99, 2001. https://doi.org/10.1038/35083620
  32. J. Zhang, M. Dong, L. Li, Y. Fan, P. Pathre, J. Dong, D. Lou, J. M. Wells, D. Olivares-Villagomez, L. Van Kaer, X. Wang, and M. Xu, "Endonuclease G is required for early embryogenesis and normal apoptosis in mice," Proceedings of the National Academy of Sciences of the United States of America, vol. 100, no. 26, pp. 15782-15787, 2003. https://doi.org/10.1073/pnas.2636393100
  33. A. P. Sinha Hikim, T. B. Rajavashisth, I. Sinha Hikim, Y. Lue, J. J. Bonavera, A. Leung, C. Wang, and R. S. Swerdloff, "Significance of apoptosis in the temporal and stage-specific loss of germ cells in the adult rat after gonadotropin deprivation," Biology of Reproduction, vol. 57, no. 5, pp. 1193-1201, 1997. https://doi.org/10.1095/biolreprod57.5.1193
  34. Y. Kon and D. Endoh, "Morphological study of metaphase-specific apoptosis in MRL mouse testis," Anatomia, Histologia, Embryologia, vol. 29, no. 5, pp. 313-319, 2000. https://doi.org/10.1046/j.1439-0264.2000.00279.x
  35. I. Kocak, M. Dundar, M. Hekimgil, and P. Okyay, "Assessment of germ cell apoptosis in cryptorchid rats," Asian Journal of Andrology, vol. 4, no. 3, pp. 183-186, 2002.
  36. M. Kato, K. Honma, T. Shigemitsu, and Y. Shiga, "Circularly polarized sinusoidal 50 Hz magnetic field exposure does not influence plasma testosterone levels of rats," Bioelectromagnetics, vol. 15, no. 6, pp. 513-518, 1994. https://doi.org/10.1002/bem.2250150604
  37. R. M. Mostafa, Y. M. Moustafa, F. M. Ali, and A. Shafik, "Sex hormone status in male rats after exposure to 50 Hz, 5 mTesla magnetic field," Archives of Andrology. vol. 52, no. 5, pp. 363-369, 2006. https://doi.org/10.1080/01485010600667092
  38. M. D. Jacobson, M. Weil, and M. C. R, "Programmed cell death in animal development," Cell, vol. 88, no. 3, pp. 347-354, 1997. https://doi.org/10.1016/S0092-8674(00)81873-5
  39. M. Hasegawa, G. Wilson, L. D. Russell, and M. L. Meistrich, "Radiation-induced cell death in the mouse testis: relationship to apoptosis," Radiation Research, vol. 147, no. 4, pp. 457-467, 1997. https://doi.org/10.2307/3579503
  40. J. H. Richburg, A. Nanez, L. R. Williams, M. Embree, and K. Boekelheide, "Sensitivity of testicular germ cells to toxicant-induced apoptosis in gld mice that express a nonfunctional form of Fas ligand," Endocrinology, vol. 141, no. 2, pp. 787-793, 2000. https://doi.org/10.1210/endo.141.2.7325
  41. M. Hasegawa, Y. Zhang, H. Niibe, N. H. Terry, and M. L. Meistrich, "Resistance of differentiating spermatogonia to radiation induced apoptosis and loss in p53-deficient mice," Radiation Research, vol. 149, no. 3, pp. 263-270, 1998. https://doi.org/10.2307/3579959
  42. J. Kwon, Y. L. Wang, R. Setsuie, S. Sekiguchi, Y. Sato, M. Sakurai, M. Noda, S. Aoki, Y. Yoshikawa, and K. Wada, "Two closely related ubiquitin C-terminal hydrolase isozymes function as reciprocal modulators of germ cell apoptosis in cryptorchid testis," American Journal of Pathology, vol. 165, no. 4, pp. 1367-1374, 2004. https://doi.org/10.1016/S0002-9440(10)63394-9
  43. A. A. van Loon, E. Sonneveld, J. Hoogerbrugge, G. P. van der Schans, J. A. Grootegoed, P. H. Lohman, and R. A. Baan, "Induction and repair of DNA single-strand breaks and DNA base damage at different cellular stages of spermatogenesis of the hamster upon in vitro exposure to ionizing radiation," Mutation Research, vol. 294, no. 2, pp. 139-148, 1993. https://doi.org/10.1016/0921-8777(93)90022-9
  44. S. Z. DeLuca and P. H. O'Farrell, "Barriers to male transmission of mitochondrial DNA in sperm development," Developmental Cell, vol. 22, no. 3, pp. 660-668, 2012. https://doi.org/10.1016/j.devcel.2011.12.021