Spermatogonial stem cells (SSCs) sustain spermatogenesis throughout life by generating differentiating spermatogonia, spermatocytes, and spermatozoa. During this process, male germ cells are interconnected by intercellular bridges (ICBs). Although ICB fragmentation has been implicated in the replenishment of the SSC pool, the molecular mechanisms underlying this process remain poorly understood. Our previous study demonstrated that JMJD3 deficiency promotes spermatogonial fragmentation and preserves spermatogenesis during ageing. To investigate the molecular basis underlying these phenotypes, we performed H3K27me3 ChIP-seq using a spermatogonia-enriched CD9-positive cell fraction together with RNA-seq of SSC-enriched spermatogonial populations from JMJD3-deficient mice. Cross-dataset comparison revealed extensive alterations in H3K27me3 landscapes accompanied by age- and JMJD3-dependent transcriptional changes. RNA-seq demonstrated downregulation of multiple signaling pathways, including NF-κB and TNF signaling, together with dysregulation of extracellular matrix (ECM)- and cell adhesion-related genes in JMJD3-deficient spermatogonia. Consistent with these transcriptional changes, JMJD3-deficient spermatogonia exhibited excessive ECM accumulation and altered expression of adhesion-associated genes in vivo. Although several mesenchymal-associated genes were upregulated, canonical cadherin switching was not observed, indicating the presence of partial epithelial-mesenchymal transition (EMT)-like transcriptional features rather than a complete EMT program. Cross-dataset comparison further identified Ptk2b as a candidate gene associated with JMJD3-dependent H3K27me3 changes. These findings suggest that JMJD3 deficiency is associated with extensive epigenomic remodeling and adhesion-related transcriptional alterations in aged spermatogonia and provide candidate molecular pathways that may contribute to the maintenance of spermatogenesis during ageing.
This study aimed to investigate the role of STOX1 in trophoblast pyroptosis during preeclampsia (PE) and elucidate its underlying molecular mechanisms. A trophoblast hypoxia cell model was established by exposing HTR-8/SVneo cells to hypoxic conditions. The results showed that STOX1 messenger RNA expression was significantly elevated in placental tissues from PE patients as well as in hypoxia-treated HTR-8/SVneo cells. Hypoxia markedly induced pyroptosis in HTR-8/SVneo cells, whereas STOX1 silencing enhanced cell proliferation and migration while suppressing programmed cell death. Moreover, STOX1 knockdown reduced the levels of reactive oxygen species and malondialdehyde, increased superoxide dismutase (SOD) activity, and decreased the expression of pyroptosis-associated inflammatory cytokines, including interleukin-1β (IL-1β) and interleukin-18 (IL-18). In addition, silencing STOX1 downregulated the expression of inflammasome-related proteins, including NLRP3, ASC, cleaved caspase-1, and GSDMD-N. Mechanistically, STOX1 knockdown activated the Nrf2/HO-1 signaling pathway, as evidenced by increased expression of Nrf2 and HO-1 and decreased expression of Keap1. Rescue experiments further demonstrated that co-silencing Nrf2 partially reversed the inhibitory effects of STOX1 knockdown on pyroptosis in hypoxia-treated HTR-8/SVneo cells. Collectively, these findings indicate that STOX1 is upregulated in PE and that STOX1 silencing alleviates oxidative stress and inhibits caspase-1-mediated trophoblast pyroptosis through activation of the Nrf2 signaling pathway. Consequently, STOX1 may serve as a promising therapeutic target for the prevention and treatment of preeclampsia.
Diminished ovarian reserve (DOR) is associated with poor reproductive outcomes; however, the underlying molecular mechanisms-particularly those involving the regulation of granulosa cell (GC) function by exosomal microRNAs (miRNAs) derived from follicular fluid-remain unclear. This study integrated clinical analysis with molecular profiling to investigate the regulatory effects of DOR patient-derived follicular fluid exosomes on GC function. Clinical data confirmed significantly poorer embryological and clinical outcomes in DOR patients. Follicular fluid was collected from patients with normal ovarian reserve (NOR) and those with DOR. Exosomes and GCs were subsequently isolated from the respective follicular fluid samples. Molecular profiling of follicular fluid exosomes and GCs from both groups identified differentially expressed miRNAs and mRNAs via next-generation sequencing. Integrated bioinformatics analysis and dual‑luciferase reporter assays confirmed that exosomal hsa‑miR‑135a‑5p directly targets and suppresses BIRC5 expression in GCs. Functional experiments demonstrated that incubating NOR GCs with DOR exosomes not only significantly downregulated BIRC5 but also induced marked cellular autophagy and mitochondrial dysfunction. These findings reveal a novel exosome‑mediated regulatory pathway in which DOR follicular fluid exosomes deliver miR‑135a‑5p to recipient GCs, repress the anti‑apoptotic gene BIRC5, and disrupt cellular homeostasis, thereby providing a potential mechanistic explanation for the compromised follicular microenvironment and adverse clinical outcomes in DOR.
Successful reproduction in eutherian mammals requires intimate connections between the embryo and uterus, involving adhesion, attachment and placentation, with or without invasion of the endometrium. The complex dialogue between embryo and uterus involves numerous molecules and pathways. The study of the mechanisms driving early embryo-uterus interactions has historically been challenging, particularly discovering the embryo-expressed molecules. Some components of the interactions have been known for decades, but many have been revealed in recent years through innovative transcriptome studies, studies of the contents and functions of extracellular particles, use of in vitro three-dimensional organoids, genetic studies, approaches for dissecting the regulation of maternal immune system cells, and many other approaches. This review focuses on embryo-expressed molecules that support implantation and embryo attachment, implantation and pregnancy establishment. Both classical and recent discoveries are examined, encompassing results from human, murine, livestock and comparative studies. Opportunities for further mechanistic insights are considered. Additionally, the review considers the potential for agricultural and clinical applications of the more recently identified molecular players and mechanisms for enhancing reproductive success or for providing new approaches to contraception.
Post-ovulatory aging (POA) reduces oocyte quality, yet effective interventions remain limited. Here we demonstrate that early intervention with vitamin K2 (menaquinone-4 isoform, MK-4) alleviates POA by inhibiting iron-disorder-induced oxidative stress. Western blot revealed that the expressions of ferroptosis suppressor protein 1 (FSP1) and vitamin K epoxide reductase-like protein (VKORC1L1) were significantly decreased in mouse POA oocytes; however, MK-4 attenuated these changes. Further, MK-4 inhibited ferritinophagy by downregulating NCOA4 and LC3II, markedly restored ferritin level, reduced intracellular Fe2+ amount, thus attenuating oxidative stress. These results were characterized by reducing lipid peroxidation marker malondialdehyde (MDA) and acyl-CoA synthetase long chain family member 4 (ACSL4) expression, decreasing γ-H2AX and 8-Hydroxy-2'-deoxyguanosine (8-OHdG), and enhancing expression of the mitochondrial antioxidant enzyme superoxide dismutase 1 (SOD1). Additionally, MK-4 suppressed mitophagy by downregulating PINK1 and Parkin, and upregulating Rab7 improving mitochondrial membrane potential. Consequently, abnormalities in chromosomes, spindles, and the cytoskeleton were significantly ameliorated in POA oocytes receiving early MK-4 intervention. Notably, in vitro-aging oocytes expressed higher FSP1 and VKORC1L1 but lower ACSL4 and MDA versus the in vivo counterparts, suggesting a milder lipid peroxidation in vitro. Collectively, our findings uncover a novel anti-aging mechanism triggered by MK-4, highlighting its potential to establish a preventive strategy for female reproductive aging.
