Dysregulation of the Acrosome Formation Network by 8-oxoguanine (8-oxoG) in Infertile Sperm: A Case Report with Advanced Techniques

• Main Authors: Sung Woo Kim, Bongki Kim, Jongsoo Mok, Eun Seo Kim, Joonghoon Park
• Format: Article
• Language: English
• Published: MDPI AG 2021-05-01
• Series: International Journal of Molecular Sciences
• Subjects: 8-oxoguanine (8-oxoG); acrosome; sperm; infertility; bull
• Online Access: https://www.mdpi.com/1422-0067/22/11/5857

8-Hydroxyguanine (8-oxoG) is the most common oxidative DNA lesion and unrepaired 8-oxoG is associated with DNA fragmentation in sperm. However, the molecular effects of 8-oxoG on spermatogenesis are not entirely understood. Here, we identified one infertile bull (C14) due to asthenoteratozoospermia. We compared the global concentration of 8-oxoG by reverse-phase liquid chromatography/mass spectrometry (RP-LC/MS), the genomic distribution of 8-oxoG by next-generation sequencing (OG-seq), and the expression of sperm proteins by 2-dimensional polyacrylamide gel electrophoresis followed by peptide mass fingerprinting (2D-PAGE/PMF) in the sperm of C14 with those of a fertile bull (C13). We found that the average levels of 8-oxoG in C13 and C14 sperm were 0.027% and 0.044% of the total dG and it was significantly greater in infertile sperm DNA (<i>p</i> = 0.0028). Over 81% of the 8-oxoG loci were distributed around the transcription start site (TSS) and 165 genes harboring 8-oxoG were exclusive to infertile sperm. Functional enrichment and network analysis revealed that the Golgi apparatus was significantly enriched with the products from 8-oxoG genes of infertile sperm (<i>q</i> = 2.2 × 10⁻⁷). Proteomic analysis verified that acrosome-related proteins, including acrosin-binding protein (ACRBP), were downregulated in infertile sperm. These preliminary results suggest that 8-oxoG formation during spermatogenesis dysregulated the acrosome-related gene network, causing structural and functional defects of sperm and leading to infertility.