Proteome analysis for profiling infertility markers in male mouse sperm after carbon ion radiation

Ion radiation or radiotherapy is used to treat male patients with oligozoospermia, azoospermia, temporarily infertility, or even permanent infertility. The present study aims to investigate the potential infertility mechanism of sperm in mice after carbon ion radiation (CIR). The caudal epididymal sperm of male mice whole-body irradiated with carbon ion beam (0.5Gy and 4Gy) were used 7 days after irradiation. A two-dimensional gel electrophoresis approach was employed to investigate the changes in protein expression in the caudal edididymal sperm. Spot detection and matching were performed using the PDQuest 8.0 software. The criteria used to select spots for the analysis were more than a threefold difference in protein quantities (normalized spot volume), which allowed the detection of six differentially expressed proteins. Protein identification was performed using MALDI-TOF-TOF. Six specific proteins were identified by searching the NCBI protein sequence database. Among these proteins, HSP 70-2, PLC, GPX4, β-tubulin, and GAPDHS were associated with sperm motility, which can affect fertility. β-tubulin is important in axoneme migration flagellar movement and regulation, and GAPDHS is related to sperm energy supply. We analyzed their expressions using immunoblotting and immunofluorescence. The changes in sperm protein expression after CIR are mainly associated with motility. These proteins are potential markers for the mechanisms of infertility in space or radiotherapy.