Correlation between PI3K/PDK1/AKT Pathway-Related Protein Levels and Sperm Motility in Duroc Boars

Male infertility is an increasing global health concern, with reduced sperm motility being a major contributing factor. Among various molecular mechanisms, the phosphoinositide 3-kinase (PI3K)/phosphoinositide-dependent protein kinase-1 (PDK1)/protein kinase B (AKT) signaling pathway has been identified as a key regulator of sperm function, particularly motility. However, the relationship between this pathway and sperm motility is not fully understood. In this study, we investigated the correlation between sperm motility and the levels of PI3K/PDK1/AKT pathway-related proteins in Duroc boar spermatozoa. Sperm motility was assessed using computer-assisted sperm analysis (CASA), and protein levels were measured via enzyme-linked immunosorbent assay (ELISA). Our results revealed significant correlations between signaling components and specific motility parameters. Notably, PI3K levels were negatively correlated with beat cross frequency (BCF), suggesting that excessive activation may impair flagellar motion. In contrast, phosphorylated PDK1 (p-PDK1) and AKT phosphorylated at Thr308 and Ser473 were positively correlated with progressive motility (PRG), supporting a role for AKT activation in enhancing forward movement. Interestingly, both PTEN and phosphorylated PTEN (p-PTEN) showed positive correlations with various velocity parameters, indicating a potential regulatory role in modulating AKT activity to maintain optimal motility patterns. While these findings enhance our understanding of sperm motility regulation, limitations include reliance on the correlation analysis and the absence of direct enzymatic activity measurements. Additionally, these results are specific to Duroc boar spermatozoa and may not be directly applicable to other species. Nonetheless, this study provides foundational insights into the molecular mechanisms underlying sperm motility and underscores the importance of the PI3K/PDK1/AKT pathway in male fertility.