CD52 as a key mediator of the immunosuppressive activity of human seminal fluid, potentially protecting sperm from immune responses in the female reproductive tract.Correnti et al. used an untargeted HPLC-MS metabolomics approach to explore the metabolic signature of human seminal fluid in cases of teratozoospermia (i.e. high prevalence of abnormal sperm morphology). Compared to normozoospermia, the seminal fluid of donors with teratozoospermia exhibited a significantly altered metabolome, characterized by 14 significantly altered metabolites related to inflammation and oxidative stress. Among those, O-acetyl-L-serine, creatine, and histidine were identified as candidate biomarkers for teratozoospermia, exhibiting a robust discriminatory power following ROC analysis. Overall, these findings suggest that inflammation and oxidative stress might be related to the pathophysiology of teratozoospermia, which provides a foundation for antiinflammatories and antioxidant therapies in the management of these patients. Using a LC-MS/MS proteomics approach, Mierzejewski et al. investigated how lipopolysaccharide (LPS)-induced inflammation affects the porcine corpus luteum during the mid-luteal phase. After 24 h of in vitro LPS exposure, 12 differently regulated proteins were identified, including increased UTP-glucose-1phosphate uridylyltransferase (UGP2) and succinate-CoA ligase GDP-forming subunit beta (SUCLG2), suggesting altered glucose metabolism and Krebs cycle activity, and increased NAD(P)dependent steroid dehydrogenase like (NSDHL), suggesting an impact on corpus luteum steroidogenesis. Consistent with these findings, glucose content was decreased in LPS-exposed corpus luteum, while progesterone increased. Together, these results show that the corpus luteum is responsive to inflammatory stimuli, leading to an altered metabolic and steroidogenic function with potential consequences for embryo implantation and early pregnancy support.Turgay et al. analyzed the inflammatory markers neutrophil gelatinase-associated lipocalin (NGAL) and matrix metallopreoteinase-9 (MMP-9) as candidate biomarkers for endometrioma. By comparing the serum levels patients with unexplained infertility (n=45) to those with diagnosed endometrioma (n=45), these authors found increased NGAL and decreased MMP-9 level in the endometrioma group, resulting in a markedly higher MMP-9/NGAL ratio. Postoperative analysis showed decreased MMP-9 levels in endometrioma patients, which brought the MMP-9/NGAL ratio in line with that of the unexplained infertility group. ROC analysis revealed an excellent discriminatory performance for MMP-9/NGAL ratio (AUC=0.898), with a proposed cutoff of >1.75 yielding 86.1% sensitivity and 84% specificity for diagnosing endometrioma. Overall, the MMP-9/NGAL ratio appears as a useful complementary tool to ultrasonography in endometrioma diagnosis.Infertility-related genetic factors were also covered in this Research Topic. Kazama et al. studied the role of transducin-like enhancer of split 6 (TLE6), a key component of the subcortical maternal complex (SCMC), in male reproductive function using a Tle6 heterozygous (Tle6 +/-) C57BL/6N mouse model generated using the CRISP-Cas9 technology. Although litter size was like wild-type mice, the offspring genotype proportion deviated from Mendelian laws. Embryos derived from Tle6 +/-mice showed normal developmental rate, which led authors to hypothesize that these mice exhibit poorer sperm quality. Despite no morphological changes in the seminiferous tubules, Tle6 +/-mice had reduced sperm count, a marked decrease in highly motile sperm, and an increased proportion of morphological defects in sperm's head. Immunofluorescence staining revealed that TLE6 localizes in the midpiece of mice's sperm, suggesting a functional role in motility and potentially in energy production. These findings indicate that TLE6 may influence spermatogenesis and sperm function, highlight the need for future human studies.Finally, Zhao et al. produced a critical narrative review on mitophagy, a selective process that preserves mitochondrial quality by removing damaged mitochondria, and its role in folliculogenesis, oocyte
Carrageta et al. (Thu,) studied this question.