Effects And Potential Mechanisms Of Electromagnetic Radiation On Male Fertility And Glucose Metabolism Of Offspring In Mice

Part 1 Effects and potential mechanisms of electromagnetic radiation on male mice fertilityPurpose:The male reproductive system is one of the most sensitive target organs for EMR(electromagnetic radiation),and it has been reported that EMR(including cell phone radiation,etc.)may cause a decrease in male sperm quality,but its effects on male fertility function and related mechanisms are unknown.In this part,a 2.0 GHz C57BL/J6 mouse electromagnetic radiation platform was built to simulate the exposure to EMR in military operations,and the effects of EMR exposure on testes,sperm quality and mating ability of mice and related mechanisms were systematically investigated,which will give us more information on the effects of EMR exposure on male fertility and the underlining mechanisms.Methods:Male mice were randomly divided into the control group(without EMR)and the radiation group(exposed to EMR).The radiation group was exposed to EMR at 2.0 GHz,power density at 2.5 W/m~2[whole-body specific absorption rate(SAR),0.125-0.5 W/kg],3 hrs per day,6 days per week,for 10 weeks.At 10 weeks of radiation exposure,a 1:1mating experiment was performed to test their fertility.Epididymal sperm quality and testicular histology were examined.Testicular proteins were extracted to determine protein expression levels of histone demethylase JMJD3/UTX.Then the potential role of JMJD3/UTX in male fertility was investigated in vivo and in vitro with the help of GSK-J4,a specific JMJD3/UTX inhibitor.Finally,transcriptome sequencing(RNA-seq)was used to reveal the possible mechanism of JMJD3/UTX regulation on spermatocyte GC-2proliferation and apoptosis.Results:Under the EMR conditions of our experiments,we observed that the testicular structure and blood-testis barrier integrity of mice did not seem to change after long-term radiation in male mice.However,the proliferation of testicular germ cells tended to decrease,accompanied by a significant increase in germ cell apoptosis.We did not find changes in sperm count and sperm ROS,although there was a trend of increased early apoptosis and dead cells in sperm cells.The histone demethylase JMJD3/UTX was significantly decreased in the testes of mice exposed to EMR,and JMJD3/UTX could regulate the proliferation and apoptosis of mouse spermatocytes in vivo and in vitro.The associated-mechanism involved the regulation of H3K27me3 by JMJD3/UTX,and the signaling pathways involved in apoptosis and proliferation impacted by JMJD3/UTX,like p53 signaling.Conclusion:Long-term EMR has no significant effects on testicular structure,blood-testis barrier integrity,and sperm quality in mice.Electromagnetic radiation can induce apoptosis of testicular germ cells.Decreased expression of histone demethylase JMJD3/UTX in testes of mice exposed to EM radiation may be involved in EMR influencing male fertility in mice.The related mechanism involves the regulation of H3K27me3 by JMJD3/UTX and the regulation of apoptosis and proliferation-related signaling pathways,such as p53 signaling.Part 2 Effects and potential mechanisms of paternal electromagnetic radiation exposure on the glucose metabolism of offspring micePurpose: The literature has reported that paternal adverse environmental exposures(e.g.,high-fat diet,environmental stress)can affect the health of offspring.The results in first part showed that electromagnetic radiation exposure did not damage the fertility of male mice,but affected some epigenetic characteristics of testis.Considering that paternal epigenetic changes may affect offspring health,electromagnetic radiation is a potential harmful environmental exposure to human health,but the effects of paternal electromagnetic radiation exposure on offspring growth and metabolism are not clear.Therefore,in this part,we will examine the growth and development,metabolism(mainly body weight and glucose metabolism),and gut microbiota of offspring from the first part of electromagnetic radiation,which will help to study more deeply the effects and possible mechanisms of electromagnetic radiation exposure on the metabolism of their offspring.Methods: Firstly,we detected the body weight and glucose tolerance of F0 mice following 14 weeks exposure.Then,weight of the offspring from the first part of EMR and control male mice was monitored.Also,the glucose metabolism of the offspring mice was detected(including fed blood glucose,fasting blood glucose,glucose tolerance test,insulin tolerance test,and pyruvate tolerance test).In addition,q PCR and 16 s r RNA sequencing were used to detect the changes of liver glucose metabolism-related genes and gut microbiota in the offspring,respectively.Results: After 14 weeks of electromagnetic radiation,the weight and glucose tolerance of F0 male mice did not get significantly changed.There exist differences in the effects of paternal EMR exposure on female and male offspring: the growth trajectory of female offspring was not affected,while male offspring lagged behind the control group in weight gain at puberty(3 weeks of age-10 weeks of age),but caught up with the control mice in weight after puberty.Glucose tolerance was influenced in the male offspring but not in the female offspring.Further studies showed that the abnormal glucose metabolism in male offspring was associated with abnormal expression of genes related to liver glucose metabolism such as Gck and G6 pc.In addition,the results of 16 S r RNA sequencing of gut microbiota in F1 male mice showed that,there was no difference between R-F1(F1 from exposed father)and C-F1(F1 from control father)on both alpha diversity and beta diversity.Bacteroides were significantly more abundant in male R-F1 than in male C-F1 mice.Reciprocally,Turicibacter were significantly more abundant in male C-F1 than in male RF1.Conclusion: Exposure to paternal EMR had no effect on offspring female growth and development and glucose metabolism.Exposure to paternal EMR could affect the growth and development and glucose metabolism of male offspring at puberty.The abnormal glucose metabolism in male offspring mice was associated with abnormal expression of genes related to glucose metabolism in the mouse liver and altered gut microbiota.