Inflammasome-related markers and long non-coding rnas in seminal plasma: Associations with sperm DNA fragmentation...

Male infertility is increasingly associated with oxidative stress, inflammation, and epigenetic changes. This study examined the relationship between sperm DNA fragmentation (SDF), inflammatory markers in seminal plasma, and long non-coding RNAs (lncRNAs) detected in whole semen cell pellets (unpurified) to identify molecular signatures linked to reduced semen quality. Participants were classified into low (<30%) and high (>30%) SDF groups using the sperm chromatin structure assay (SCSA) (n = 30 per group). Semen parameters, residual histone content, inflammasome-related proteins in seminal plasma NLRP3 (NOD-like receptor family, pyrin domain-containing 3(, caspase-1, IL-1β (Interleukin-1 beta), IL-18(Interleukin-18), and lncRNA expression MALAT1(Metastasis Associated Lung Adenocarcinoma Transcript 1), ANRIL (Antisense Non-coding RNA in the INK4 Locus), MEG3 (Maternally Expressed Gene 3), and NLRP3 mRNA were analyzed. Although semen volume and total sperm count were similar between groups, the high-SDF group showed lower sperm concentration, motility, and viability, as well as higher residual histones. In an exploratory ELISA subset (n = 5 per group), seminal plasma from men with high SDF contained higher concentrations of NLRP3, caspase-1, IL-1β, and IL-18, which were associated with increased inflammatory marker levels. Expression analysis also tended to show higher MALAT1lncRNA and NLRP3 mRNA detected in whole semen cell pellets (unpurified) of the high-SDF group, while ANRIL and MEG3 remained unchanged. Correlation results revealed positive associations between ANRIL and sperm count, and between MEG3 and ANRIL, whereas motility was inversely associated with MALAT1 and NLRP3. SDF further showed a positive correlation with NLRP3 levels. Findings suggest that elevated inflammatory mediators in seminal plasma, along with increased MALAT1 and NLRP3 transcripts detected in whole semen cell pellets (unpurified), are associated with higher sperm DNA fragmentation. Because inflammasome activity was not directly measured and RNA was extracted from whole semen cell pellets (unpurified) rather than isolated sperm fractions, these results should be interpreted as exploratory associations compatible with a potential link between inflammatory processes and sperm DNA instability.