Search Results (214)

Aging disrupts sleep, but how these changes are structured across circadian time, vigilance states, and sex remains poorly understood, because most prior studies used single-sex cohorts and few days of recordings. We continuously recorded 14 days of EEG/EMG in 24 C57BL/6J mice using a balanced 2 × 2 design (young vs. old; male vs. female; n = 6/group). A comprehensive multiscale analysis of the extended dataset enabled detailed reconstruction of 24 h sleep–wake architecture, better characterization of natural day-to-day variability including across multiple estrous cycles, and detection of rare bouts and transition events. Across seven levels of analysis, from circadian profiles to EEG spectral parameterization, the strongest aging effect was a dark-phase-specific 17–18% loss of theta-dominant active wake (TDW) in both sexes, with reciprocal increases in quiet wake (nTDW) and NREM sleep. We also identified a recurring N-shaped structural motif at the dark-to-light transition, where age-related and several sex-associated differences were most apparent. Broadly, old mice exhibited (i) shorter TDW bouts; (ii) a shift in NREM exit kinetics toward wakefulness; (iii) more brief and poorly consolidated “out-block” NREM episodes; and (iv) a slowing of waking theta and higher low-frequency TDW power. Variance decomposition indicated that statistical power depends more on sample size than on recording length. Together, aging reflects a coordinated, circadian-phase-specific reorganization of sleep–wake architecture. Sex-related and interaction findings should be interpreted as hypothesis-generating pending larger cohorts. Full article

Pregnancy modulates the function of the thyroid gland to facilitate maternal immune tolerance, and nuclear factor kappa B (NF-κB) subunits, the IκB family, and toll-like receptors (TLRs) and complement signaling pathways may be implicated in maternal thyroid immunoregulation. However, it is unclear whether early pregnancy modulates the expression of NF-κB subunits, the IκB family, TLRs, and complement components in the maternal thyroid. The objective of this study was to analyze the effects of early pregnancy on the expression of genes and proteins of these signaling pathways in the maternal thyroid in ewes. In this study, ovine thyroids (n = 6 for each group) were sampled on day 16 of the estrous cycle (N16) and on days 13, 16, and 25 of pregnancy (P13, P16, and P25) with one conceptus. The ewes had an average weight of 41 kg and a body condition score of 3. The mRNA and protein expression of the NF-κB subunits and IκB family were analyzed by RT-qPCR, western blot, and immunohistochemistry. The results showed that the expression of all NF-κB subunits, the IκB family, and TLRs, as well as C1q, C1r, C2, C4a, C5b, and C9, peaked at P16 among these four stages (p < 0.05). In addition, C1s expression was greater at N16 and P16 than at P13 and P25 (p < 0.05), and C3 expression was stronger at P16 and P25 compared to N16 and P13 (p < 0.05). In conclusion, early pregnancy modulates the expression of NF-κB subunits, the IκB family, TLRs, and complement components in the ovine thyroid at both the mRNA and protein levels, which may be essential for maternal thyroid adaptation to pregnancy and beneficial for the prevention of pregnancy-related thyroid diseases in ewes. Full article

Characterizing the microbiota is essential to improve the understanding and management of urogenital disorders. Using 16S rDNA sequencing, this study investigated the urogenital microbiota, including urine, vaginal, and prostatic communities, in a litter of 10 healthy beagle puppies from 4 months of age until the completion of the first estrous cycle in females and 18 months in males. A further objective was to compare these microbial profiles with those of their dam. Significant differences were observed between urinary and genital microbiota in both sexes, evolving over time. Notably, in females, puberty and the first estrous cycle were associated with marked changes in the vaginal microbiota, outweighing individual variability. In contrast, urinary microbiota remained stable during female growth. In males, microbiota showed time-dependent and individual-specific progression, with distinct microbial communities identified in the urinary bladder and prostate. Shared genera between the dam and her offspring were observed, but inter-individual variability suggested a limited maternal influence. Further investigation is needed to clarify vertical transmission patterns. In conclusion, the urogenital microbiota of healthy dogs undergoes dynamic and distinct site-specific changes during early life. Full article

Duolang sheep, an indigenous breed of southern Xinjiang, are significant for their agricultural systems due to their adaptation to arid and semi-arid environments. This review integrates recent advancements in Duolang’s reproductive biology, genomic studies, and management strategies to address the breed’s reproductive efficiency under challenging ecological conditions. Reproductive traits such as puberty onset, estrous cycle characteristics, and seasonal breeding are influenced by complex genetic and several environmental factors. Numerous remarkable genomic findings highlight key loci related to fecundity, including the Booroola FecB mutation, as well as genes involved in steroidogenesis, folliculogenesis, and HPG axis regulation. Despite the genetic potential for increased prolificacy, Duolang sheep often exhibit low litter sizes, largely constrained by detrimental environmental factors and management practices. This review emphasizes the significance of integrating genetics, nutrition, and reproductive management to optimize productivity. Strategies such as nutritional flushing, hormone-based estrous synchronization, and selective breeding for increased litter size are discussed, with a focus on minimizing the risks associated with early puberty and lamb survival. Furthermore, the review explores the potential of genomic selection, marker-assisted breeding, and advanced reproductive technologies to enhance the breed’s performance. Finally, the review outlines future research directions, necessitating the development of genomic resources, precise breeding programs, and field trials on reproductive interventions to accelerate genetic gains in Duolang sheep. This integrated approach promises to improve reproductive outcomes, with implications for sustainable sheep production in Xinjiang and similar environments across the globe. Full article

Females with iron overload suffer from follicular dysplasia, and effective therapeutic strategies for preserving fertility remain lacking. As a natural aliphatic polyamine, spermidine exerts antioxidant activity and plays an anti-ferroptosis role in the pathogenesis of various diseases. However, the role and underlying mechanism of spermidine in iron overload-induced ovarian ferroptosis remain largely elusive. This study aimed to investigate the therapeutic potential of spermidine against iron overload-induced ferroptosis in ovarian granulosa cells and elucidate its molecular mechanism. As a result, iron overload models were established in female mice (in vivo, ferrous sulfate) and porcine ovarian granulosa cells (in vitro, ferric ammonium citrate), with spermidine administered at 3 mM (in vivo) or 150 μM (in vitro). Ferritin heavy chain (FHC) and solute carrier family 7 member 11 (SLC7A11) silencing were performed via siRNA transfection, and relevant controls were set. In vivo studies showed that spermidine elevated serum estradiol and progesterone levels, enhanced ovarian catalase (CAT) and superoxide dismutase (SOD) activities, improved granulosa cell mitochondrial morphology, and increased estrous cycle regularity from 35.6% (high-iron group) to 63.1%. In vitro, spermidine improved ferric ammonium citrate (FAC)-impaired cell viability; attenuated reactive oxygen species (ROS) accumulation; upregulated FHC, Nrf2/p-Nrf2/GPX4, SLC7A11 and anti-müllerian hormone (AMH) expression; and inhibited excessive autophagy (decreased LC3BII/I ratio). Mechanistically, spermidine activated AKT-mediated autophagy, modulated iron homeostasis and glutathione (GSH) synthesis via FHC, alleviated ferroptosis-related Nrf2/p-Nrf2/HO-1 pathway overactivation, reduced lipid peroxidation and DNA damage, and restored mitochondrial function. SLC7A11 silencing disrupted glutathione metabolism, induced mitochondrial ROS accumulation, and inhibited autophagy. Proteomic analysis identified microsomal glutathione S-transferase 3 (MGST3) as a potential key downstream target of spermidine in suppressing SLC7A11-mediated ferroptosis. This study reveals a novel therapeutic strategy wherein spermidine protects against ovarian ferroptosis and preserves ovarian function by regulating iron homeostasis through the FHC/SLC7A11 axis. Full article

Premature ovarian insufficiency (POI) impairs fertility and health in reproductive-age women, with autoimmune factors contributing to 4–30% of cases. To investigate immune dysregulation in POI, we developed two mouse models using pZP3 induction: regular immune (RE-POI) and enhanced immune (EN-POI) cycles. The EN-POI model exhibited stable, irreversible ovarian dysfunction, including disrupted estrous cycles, hormonal changes (elevated FSH, decreased AMH, and estradiol), follicular depletion, and infertility. Immune profiling demonstrated consistent T-lymphocyte imbalance across both RE-POI and EN-POI model groups, characterized by expanded splenic CD4⁺ T cells, diminished regulatory T cells, elevated systemic inflammatory cytokines, and ovarian fibrosis. Proteomic comparison between the control and EN-POI groups identified 198 differentially expressed proteins, mainly enriched in immune and inflammatory pathways. Based on these differential proteins, subsequent network analysis further identified six key hub proteins, namely Mmp9, Isg15, Ikbke, Siglec1, Pf4, and Cdkn1b. This study establishes a stable autoimmune POI model, elucidates T-cell imbalance with cytokine storm and fibrosis, and identifies key molecules linking immune abnormalities to ovarian failure, offering new insights into POI research. Full article

This study aimed to explore the alleviating effects of fisetin, a polyphenolic flavonoid, on ovarian dysfunction in a D-galactose (D-gal)-induced aging mouse model, as well as the underlying mechanisms, using both in vivo and in vitro experiments. Mice were subcutaneously injected with D-gal (100 mg/kg/day) for 60 days to establish the ovarian aging model; during the final 30 days, fisetin (10, 20, 30 mg/kg/day) was given orally. In addition, a senescent model of granulosa cell (GC) was established using D-gal and treated with fisetin. Fisetin supplementation improved ovarian endocrine function and reproductive capacity in aging mice, as reflected by regularized estrous cycles, elevated estradiol levels, and increased embryo numbers. Furthermore, fisetin reduced the number of atretic follicles and the extent of ovarian fibrosis and senescence, while simultaneously restoring the proliferation-apoptosis balance in follicular GCs, as well as alleviating oxidative stress. RNA-sequencing revealed that AMP-activated protein kinase (AMPK)/mechanistic target of rapamycin (mTOR) signaling and mitophagy were involved in the protective effects of fisetin against ovarian aging. Consistently, fisetin treatment promoted mitophagy, accompanied by AMPK/mTOR activation in ovarian tissues and GCs following D-gal exposure. Inhibition of AMPK attenuated the effect of fisetin on mitophagy. Additionally, blockage of mitophagy also reversed the beneficial effects of fisetin on mitochondrial injury, oxidative stress, cell cycle arrest, and cellular senescence in D-gal-induced senescent GCs. These findings indicate that fisetin prevents ovarian aging by suppressing follicular GC oxidative damage and ameliorating cell cycle arrest via activation of AMPK/mTOR-mediated mitophagy, thereby preserving female fertility. Full article

The uterine microbiome plays a critical role in maintaining pH balance, modulating the immune system, and influencing fertility, especially in artificial breeding contexts. This study examined the impact of uterine microbiota on pregnancy success in cows following embryo transfer (ET), using Illumina 16S rRNA gene sequencing of the V4 hypervariable region of samples collected from the uterine horn (UH) and the uterine body (UB) of cows during the estrous cycle preceding synchronization for ET in the Amazon region. Microbiomes from the uterine horn (UH) and the uterine body (UB) were analyzed before embryo transfer. Cows that became pregnant (UH-P and UB-P) and those that did not (UH-NP and UB-NP) were compared. Fifteen cows were grouped as follows: UB-P (three), UB-NP (five), UH-P (three), and UH-NP (four). Linear discriminant analysis effect size and heat tree analyses identified Sphingobacterium and Stenotrophomonas spp. as significantly enriched in the UB-P and UH-NP groups, respectively. Additionally, non-pregnant cows exhibited more distinctive genera than pregnant ones. These findings suggest that cows achieving pregnancy have lower microbial diversity and fewer potentially pathogenic genera. This study contributes to the emerging field of pre-pregnancy uterine microbiome research in cattle, offering evidence that microbial composition may influence reproductive success, and highlights specific taxa as potential biomarkers for pregnancy outcomes following embryo transfer. Full article

Paroxetine, a selective serotonin reuptake inhibitor commonly used to treat various psychiatric disorders, may adversely affect female reproductive function. Although apigenin has been shown to ameliorate reproductive abnormalities and ovarian dysfunction, its effect on paroxetine-induced reproductive toxicity in females remains unclear. Therefore, this study investigated the potential protective effects of apigenin against paroxetine-induced reproductive alterations in female rats. Female rats with regular estrous cycles were randomly assigned to four groups (n = 9 per group): control, apigenin, paroxetine, and paroxetine + apigenin. The rats received saline, apigenin (20 mg/kg), paroxetine (10 mg/kg), or their combination by oral gavage once daily for about 29 consecutive days. Compared with paroxetine treatment alone, apigenin co-administration restored decreased serum anti-Müllerian hormone (AMH) levels, enhanced PAS reactivity in the zona pellucida, reduced ovarian iNOS immunoreactivity, increased follicle and corpus luteum numbers, and increased ovarian VEGF immunoreactivity. However, apigenin administration alone was associated with reduced testosterone levels and alterations in certain ovarian and uterine histological features in female rats. In conclusion, the findings suggest that apigenin may ameliorate paroxetine-induced reproductive alterations in female rats by modulating AMH levels, follicle and corpus luteum numbers, and ovarian histochemical and molecular parameters. Full article

Objectives: Females are often underrepresented in preclinical fear research due to concerns over estrous cycle related variability. This study examined whether there were differences between female and male C57BL/6J mice in terms of fear extinction and safety learning, aiming to verify the inclusion of both sexes in fear regulation research. Methods: Mice underwent a 5-day fear conditioning and extinction protocol, with recent (Day 6) and remote (Day 13) retrieval tests. A separate cohort received unpaired tone-shock safety conditioning over two days, followed by recent and remote retrieval. Freezing percentage and locomotor distance, among other measures, were quantified to compare behavioral responses between sexes. Results: During fear acquisition and extinction, females and males showed comparable conditioned fear and progressive extinction, with no sex differences in freezing percentage, bout counts, or locomotor distance. Freezing remained low during both recent and remote retrieval in both sexes. In the safety-conditioning task, the safety cue reduced freezing relative to contextual baseline, contextual freezing declined from recent to remote retrieval, and no sex differences were observed across measures. Conclusions: Female and male C57BL/6J mice exhibit equivalent performance in auditory fear conditioning, extinction, retrieval, and safety learning under matched conditions. These findings support equitable inclusion of both sexes in preclinical fear-regulation studies, enhancing translational relevance without added behavioral variability. Full article

Backgrounds: Premature ovarian insufficiency (POI) is a clinical syndrome characterized by premature ovarian dysfunction, amenorrhea, and infertility. Ferulic acid (FA) is a prominent bioactive phenolic compound derived from traditional Chinese herbs Angelica sinensis (Oliv.) Diels and Ligusticum chuanxiong Hort. These herbs are commonly used to treat gynecological disorders including menstrual irregularities and infertility, and are known to modulate endoplasmic reticulum (ER) stress. However, the therapeutic potential and molecular mechanisms of FA in the context of POI remain largely unexplored. This study aimed to investigate the protective effects of FA against POI and to elucidate the underlying pharmacological mechanisms. Methods: In vivo, a mouse model of POI was established via a single intraperitoneal injection of cyclophosphamide (CTX; 120 mg/kg), and using FA for 28 days of continuous gavage to observe its therapeutic effect. Ovarian function and pathological changes were assessed by hormone levels, follicle development and oxidative stress (OS) level. In vitro, the effects of FA were examined using 4-hydroperoxy cyclophosphamide (4-OHCP)-treated KGN granulosa cells. Transcriptome sequencing, molecular docking, and molecular dynamics simulations were employed to identify potential targets of FA. Results: Our findings demonstrated that FA administration helped preserve regular estrous cycles, promoted follicle development and hormone secretion, and attenuated OS in both ovarian tissue and granulosa cells (GCs). Transcriptomic profiling combined with molecular docking and molecular dynamics simulations suggested that FA potentially targets key ER stress proteins, specifically Grp78 and Perk. Further in vivo and in vitro experiments confirmed that FA alleviates ER stress by inhibiting the overactivation of the Perk/eIF2α/ATF4/CHOP signaling pathway. Notably, the protective effects of FA were comparable to those of the ER stress inhibitor 4-Phenylbutyric acid (4-PBA) and were reversed by the ER stress activator tunicamycin (TM). Additionally, FA downregulates ERO1α expression, further blocking secondary oxidative damage triggered by ER stress. In KGN cells, FA significantly inhibits 4-OHCP-induced apoptosis and upregulates the anti-apoptotic proteins BCL-2 and BCL-xL, exhibiting efficacy similar to 4-PBA. Conclusions: FA improves ovarian function in CTX-induced POI by coordinately regulating OS and ER stress, inhibiting the Perk/eIF2α/ATF4/CHOP pathway, and suppressing GC apoptosis. These findings provide experimental evidence supporting FA as a potential therapeutic candidate for POI. Full article

Polycystic ovary syndrome (PCOS) is associated with impaired ovarian steroidogenesis and ovulation, which necessitates the development of effective ovulation inducers for PCOS. The aim of the study was to evaluate the effects of allosteric luteinizing hormone receptor agonist TP03 and human chorionic gonadotropin (hCG) on ovarian steroidogenesis, as well as ovulation in prepubertal female rats with dehydroepiandrosterone(DHEA)-induced PCOS. Taking into account differences in progesterone levels, cohorts with high (PCOS(H)) and low (PCOS(L)) progesterone were formed and treated with Follimag and Cetrotide. After 48 h, TP03 (25 mg/kg) or hCG (25 IU/rat) were injected, and hormone levels, gene expression, and ovarian morphology were assessed. The PCOS(H)-cohort exhibited irregular estrous cycles, ovarian cysts, and increased ovarian mass and estradiol levels, but the number of corpora lutea (CL) was maintained. In the PCOS(L)-cohort, ovarian weight was increased, and Star, Cyp11a1, and Adamts1 gene expression as well as the CL number were decreased. In both cohorts, TP03 and hCG increased progesterone levels and the expression of steroidogenesis (Star, Cyp11a1) and ovulation (Cox2, Adamts1, Egr1) genes, as well as inducing CL formation. Thus, TP03, like hCG, stimulates steroidogenesis and ovulation in PCOS-rats with different progesterone levels, which provides the first evidence of the effectiveness of allosteric LHR agonists as ovulation triggers in PCOS. Full article

Cold exposure may influence reproductive health through vascular changes, yet its mechanisms remain underexplored. This study aimed to investigate the impact of cold exposure on uterine blood vessels and the expression of the AMPK/PGC-1α gene and protein in adult female SD rats. A primary dysmenorrhea model was established in female Sprague Dawley rats and subjected to continuous cold exposure. Changes in body weight, ear temperature, and estrous cycle were observed. Superoxide dismutase (SOD) activity and adenosine triphosphate (ATP) levels were measured to assess oxidative stress. Uterine tissue morphology was assessed via small animal ultrasound, microcirculation observed using RFLSI imaging, and vascular morphology along with caspase-3 and AMPK expression evaluated histologically and immunohistochemically. CD31 and TUNEL double immunofluorescence were used to assess vascular endothelial apoptosis levels. Western blot was used to analyze Bax, BCL-2, and pAMPK/AMPK expression levels. In vitro injury models were used to treat human umbilical vein endothelial cells (HUVECs) with cold stimulus using the AMPK inhibitor Compound C. RT-PCR quantified Bax, AMPK, p53, and PGC-1α expression. Hypothermia-exposed rats exhibited significantly reduced body weight and ear temperature (p < 0.05), prolonged estrous cycle (p < 0.01), and decreased uterine index (p < 0.01), accompanied by reduced SOD and ATP levels (p < 0.01, p < 0.05). Ultrasound and flow imaging revealed decreased uterine blood flow velocity in the hypothermia group (p < 0.01). Histomorphology revealed disorganized uterine cell arrangement, reduced uterine vessel count (p < 0.01), and increased mean vessel area (p < 0.01) in cold-exposed uteri. Immunofluorescence detection revealed increased vascular endothelial cell apoptosis (p < 0.05). Western blot results showed that proapoptotic protein Bax was upregulated (p < 0.01), Bcl-2 was downregulated (p < 0.05), p-AMPK and p-AMPK/AMPK ratio were elevated (p < 0.01) after cold exposure; Rt-qPCR results indicated that Bax and P53 mRNA were increased (p < 0.01), while PGC-1α expression was elevated (p < 0.01). Rt-qPCR results showed elevated Bax and p53 mRNA (p < 0.01), along with increased AMPK and PGC-1α expression (p < 0.01) in the cold-exposed group. In human umbilical vein endothelial cells (HUVECs), compound C attenuated cold-induced effects (p < 0.01) and downregulated Bax and AMPK expression (p < 0.01). Cold exposure exacerbates uterine oxidative stress and energy imbalance, disrupts microcirculatory homeostasis, and induces endothelial cell apoptosis. Excessive phosphorylation of AMPK may co-activate PGC-1α, jointly contributing to cold-induced uterine dysfunction and exacerbated dysmenorrhea. This study reveals potential signaling pathways underlying cold-induced uterine vascular abnormalities, providing novel theoretical foundations and targeted intervention strategies for the prevention and treatment of primary dysmenorrhea. Full article

The present study investigated the impact of microplastics, specifically polystyrene microparticles (PS-MP), on the hypothalamic-pituitary-gonadal (HPG) neurohormonal axis, which regulates reproductive functions in animals and humans. The primary objective was to examine the effects of PS-MP on the expression of key genes and hormone concentrations within the gonadotropic system of sheep. Two doses of PS-MP—the lower dose (LD; 0.015 mg/kg) and the higher dose (HD; 0.15 mg/kg)—were administered intravenously every three days over two estrous cycles (34 days). Both doses significantly decreased the relative abundance of gonadotropin-releasing hormone (GnRH) transcripts in the mediobasal hypothalamus (MBH), whereas only the HD reduced GnRH mRNA levels in the preoptic area (POA). These transcript-level changes were not accompanied by detectable alterations in GnRH protein concentration. In the MBH, the expression of kisspeptin (KISS-1) and neurokinin B (NKB) genes decreased following exposure to the HD, whereas in the POA, significant decrease in expression were observed only after the LD administration. Changes in prodynorphin (PDYN) gene expression were confined to the MBH and were dose-dependent: the LD increased transcript levels, whereas the HD caused a decrease. The HD of PS-MP also significantly downregulated GnRH receptor (GnRHR) expression in the anterior pituitary (AP). Both PS-MP doses resulted in marked reductions in luteinizing hormone beta (LHβ) and follicle-stimulating hormone beta (FSHβ) subunit gene expression in the AP, without significant changes in hormone protein concentrations. Exposure to PS-MP reduced plasma LH and FSH concentrations: the lower dose reduced both hormones, while the higher dose significantly reduced mainly FSH, showing statistical differences between doses. To summarize, the present study demonstrates that PS-MP exerts a modulatory effect on the secretory activity of the central reproductive system in sheep, at both the hypothalamic and pituitary levels. Consequently, PS-MP has the potential to induce significant disruptions to the reproductive processes of large farm animals. Full article

In the past, bacteria detected in the mare’s uterus were generally interpreted as a sign of endometritis, since the uterus was considered a sterile environment. This assumption has been challenged by the introduction of culture-independent molecular techniques, particularly 16S rRNA amplicon sequencing, which have demonstrated that healthy mares harbor an endometrial microbiota. The aim of this study was to characterize the endometrial microbiota of healthy mares and to determine whether microbial composition differs between estrus and diestrus. Endometrial samples were collected from eleven healthy Standardbred mares during estrus and diestrus and analyzed by sequencing the V1–V2 region of the bacterial 16S rRNA gene. A total of 24 bacterial phyla and 599 genera were identified. At the phylum level, Firmicutes, Proteobacteria, Bacteroidota, and Actinobacteriota accounted for most of the relative abundance, while the most abundant genera were Staphylococcus, Acinetobacter, Sphingomonas, Corynebacterium, Streptococcus, Clostridium, and Pseudomonas. Alpha diversity was significantly higher during estrus, likely due to hormonally mediated changes in cervical opening and local immunity. Beta diversity analyses showed substantial overlap between estrus and diestrus samples. The phase of the cycle had a weak effect on microbiota structure, while inter-individual differences between mares explained a larger proportion of the observed variation. These findings suggest that the uterine microbiota of healthy mares is largely stable across the estrous cycle, with phase-dependent and mare-specific fluctuations in microbial composition. Full article