Cuproptosis mediates copper-induced testicular spermatogenic cell death

Cuproptosis, a novel mechanism of programmed cell death, has not been fully explored in the context of spermatogenic cells. This study investigated the potential involvement of cuproptosis in spermatogenic cell death using a mouse model of copper overload. Sixty male Institute of Cancer Research (ICR) mice were randomly divided into four groups that received daily oral gavage with sodium chloride (control) or copper sulfate (CuSO 4 ) at 50 mg kg -1 , 100 mg kg -1 , or 200 mg kg -1 , for 42 consecutive days. Mice subjected to copper overload exhibited a disruption in copper homeostasis. Additionally, significant upregulated expression of key cuproptosis factors was accompanied by a significant rise in the rates of testicular tissue cell apoptosis. Immunohistochemical analysis revealed the presence of ferredoxin 1 (Fdx1) in Sertoli cells, Leydig cells, and spermatogenic cells at various stages of testicular development, and the Fdx1-positive staining area was significantly increased in copper-overloaded mice. Mitochondrial dysfunction and decreased adenosine triphosphate levels were also observed, further implicating mitochondrial damage under cuproptosis. Further analyses revealed pathological lesions and blood-testis barrier destruction in the testicular tissue, accompanied by decreased sperm concentration and motility, in copper-overloaded mice. In summary, our results indicate that copper-overloaded mice exhibit copper homeostasis disorder in the testicular tissue and that cuproptosis participates in spermatogenic cell death. These findings provide novel insights into the pathogenic mechanisms underlying spermatogenic cell death and provide initial experimental evidence for the occurrence of cuproptosis in the testis.