The Protective Effect Of Nano-Se On Oxidative Stress,Apoptosis And DNA Damage Induced By Copper Sulfate In Mice Testis

Copper is an essential mineral element for animal growth.Due to industrial pollution and irrational use in agriculture,animals and humans are often exposed to excessive copper.Studies have shown that copper excess can cause damage to the reproductive system.Excessive copper can cause oxidative stress,cell apoptosis and DNA damage.Selenium nanoparticles is a new type of selenium supplement,which can improve the deficiency of traditional selenium supplements and maintain its physiological activity.Selenium nanoparticles have good antioxidant activity and can alleviate the poisoning of many heavy metals.At present,there is no report on the protective effect of selenium nanoparticles on the testis of mice with copper excess.This study aims to explore the protective effect of selenium nanoparticles on the testis of mice with copper excess from the aspects of oxidative stress,apoptosis and DNA damage.In this study,240 ICR male mice were randomly divided into 8 groups:control group,40mg/kg CuSO₄group,0.5 mg/kg Nano-Se group,1 mg/kg Nano-Se group,2 mg/kg Nano-Se group,CuSO₄+0.5 mg/kg Nano-Se group,CuSO₄+1 mg/kg Nano-Se group and CuSO₄+2mg/kg Nano-Se group,after 28 days of continuous administration,histopathology,immunohistochemistry,fluorescence quantitative PCR,Western blot were used to investigate the protective effect of selenium nanoparticles on oxidative stress,apoptosis and DNA damage in the testis of male mice induced by copper sulfate.The results were as follows:（1）The effect of Nano-Se on sperm quality of mice with copper excess:the sperm motility and density of CuSO₄group were decreased significantly（P<0.01）,and the rate of abnormal sperm increased significantly（P<0.01）with control group;the CuSO₄+Nano-Se group had significantly higher sperm motility and density than the CuSO₄group（P<0.01）,and the rate of abnormal sperm decreased significantly（P<0.01）.（2）The effects of Nano-Se on the structure and function of testis in mice with copper excess:compared with control group,the Cu content in the testis of CuSO₄group was significantly increased（P<0.01）,testicular index decreased significantly（P<0.05）,the structure of seminiferous tubules was disordered,the thickness of seminiferous epithelium was reduced and a large number of vacuoles were present,the nucleus of spermatogenic cells appeared vacuolated,the number of spermatogenic cells at all levels and Johnsen’s score were significantly decreased（P<0.01）,serum testosterone level decreased significantly（P<0.05）;compared with CuSO₄group,the CuSO₄+Nano-Se group had a significant reduction in testicular copper content（P<0.01）,testicular index increased significantly（P<0.01）,testicular pathological damage was alleviated,and serum testosterone level was significantly increased（P<0.05 or P<0.01）.（3）The effects of Nano-Se on the oxidative stress of testis in mice with copper excess:compared with the control group,the ROS content in the testis of CuSO₄-exposed mice was significantly increased（P<0.01）,T-AOC,GSH,SOD,CAT activities significantly decreased（P<0.01）;compared with CuSO₄group,the CuSO₄+Nano-Se group had significantly decreased ROS content（P<0.01）,and the activities of antioxidant enzymes significantly increased（P<0.05 or P<0.01）.（4）The effects of Nano-Se on apoptosis of testis in mice with copper excess:compared with the control group,the m RNA expressions of Caspase-3,Caspase-9,Caspase-12,Bax/Bcl-2 and the protein expression of Cleaved-Caspase-3,Cleaved-Caspase-9,Cleaved-Caspase-12,Bax/Bcl-2 in the testis of CuSO₄group were significantly increased（P<0.01）;compared with CuSO₄group,the CuSO₄+Nano-Se group showed a significant decrease（P<0.05 or P<0.01）.（5）The effects of Nano-Se on DNA damage of testis in mice with copper excess:compared with the control group,the expression ofg-H2AX protein in CuSO₄treated mice was significantly increased（P<0.01）;compared with CuSO₄group,the CuSO₄+Nano-Se group showed a significant decrease（P<0.05 or P<0.01）.In conclusion,CuSO₄can cause structural damage and functional decline of testis in mice,decrease sperm quality,and induce oxidative stress,apoptosis and DNA damage in mice.Nano-Se has a protective effect on the testis of mice with copper poisoning by reducing oxidative stress,apoptosis and DNA damage.