Involvement of the up-regulated FoxO1 expression in follicular granulosa cell apoptosis induced by oxidative stress

ADPN Regulates Oxidative Stress-Induced Follicular Atresia in Geese by Modulating Granulosa Cell Apoptosis and Autophagy

Geese are susceptible to oxidative stress during reproduction, which can lead to follicular atresia and impact egg production. Follicular atresia is directly triggered by the apoptosis and autophagy of granulosa cells (GCs). Adiponectin (ADPN), which is secreted by adipose tissue, has good antioxidant and anti-apoptotic capacity, but its role in regulating the apoptosis of GCs in geese is unclear. To investigate this, this study examined the levels of oxidative stress, apoptosis, and autophagy in follicular tissues and GCs using RT-qPCR, Western blotting, immunofluorescence, flow cytometry, transcriptomics and other methods. Atretic follicles exhibited high levels of oxidative stress and apoptosis, and autophagic flux was obstructed. Stimulating GCs with H2O2 produced results similar to those of atretic follicles. The effects of ADPN overexpression and knockdown on oxidative stress, apoptosis and autophagy in GCs were investigated. ADPN was found to modulate autophagy and reduced oxidative stress and apoptosis in GCs, in addition to protecting them from H2O2-induced damage. These results may provide a reasonable reference for improving egg-laying performance of geese.

Pyrroloquinoline quinone promotes human mesenchymal stem cell-derived mitochondria to improve premature ovarian insufficiency in mice through the SIRT1/ATM/p53 pathway

BACKGROUND

DNA damage and oxidative stress induced by chemotherapy are important factors in the onset of premature ovarian insufficiency (POI). Studies have shown that mitochondria derived from mesenchymal stem cells (MSC-Mito) are beneficial for age-related diseases, but their efficacy alone is limited. Pyrroloquinoline quinone (PQQ) is a potent antioxidant with significant antiaging and fertility enhancement effects. This study aimed to investigate the therapeutic effect of MSC-Mito in combination with PQQ on POI and the underlying mechanisms involved.

METHODS

A POI animal model was established in C57BL/6J mice by cyclophosphamide and busulfan. The effects of MSC-Mito and PQQ administration on the estrous cycle, ovarian pathological damage, sex hormone secretion, and oxidative stress in mice were evaluated using methods such as vaginal smears and ELISAs. Western blotting and immunohistochemistry were used to assess the expression of SIRT1, PGC-1α, and ATM/p53 pathway proteins in ovarian tissues. A cell model was constructed using KGN cells treated with phosphoramide mustard to investigate DNA damage and apoptosis through comet assays and flow cytometry. SIRT1 siRNA was transfected into KGN cells to further explore the role of the SIRT1/ATM/p53 pathway in combination therapy with MSC-Mito and PQQ for POI.

RESULTS

The combined treatment of MSC-Mito and PQQ significantly restored ovarian function and antioxidant capacity in mice with POI. This treatment also reduced the loss of follicles at various stages, improving the disrupted estrous cycle. In vitro experiments demonstrated that PQQ facilitated the proliferation of MitoTracker-labelled MSC-Mito, synergistically restoring mitochondrial function and inhibiting oxidative stress in combination with MSC-Mito. Both in vivo and in vitro, the combination of MSC-Mito and PQQ increased mitochondrial biogenesis mediated by SIRT1 and PGC-1α while inhibiting the activation of ATM and p53, consequently reducing DNA damage-mediated cell apoptosis. Furthermore, pretreatment of KGN cells with SIRT1 siRNA reversed nearly all the aforementioned changes induced by the combined treatment.

CONCLUSIONS

Our research findings indicate that PQQ facilitates MSC-Mito proliferation and, in combination with MSC-Mito, ameliorates chemotherapy-induced POI through the SIRT1/ATM/p53 signaling pathway.

Melatonin protects oogenesis from hypobaric hypoxia-induced fertility damage in mice

Environmental hypoxia adversely affects reproductive health in humans and animals at high altitudes. Therefore, how to alleviate the follicle development disorder caused by hypoxia exposure and to improve the competence of fertility in plateau non-habituated female animals are important problems to be solved urgently. In this study, a hypobaric hypoxic chamber was used for 4 weeks to simulate hypoxic conditions in female mice, and the effects of hypoxia on follicle development, proliferation and apoptosis of granulosa cells, reactive oxygen species (ROS) levels in MII oocyte and 2-cell rate were evaluated. At the same time, the alleviating effect of melatonin on hypoxic exposure-induced oogenesis damage was evaluated by feeding appropriate amounts of melatonin daily under hypoxia for 4 weeks. The results showed that hypoxia exposure significantly increased the proportion of antral follicles in the ovary, the number of proliferation and apoptosis granulosa cells in the follicle, and the level of ROS in MII oocytes, eventually led to the decline of oocyte quality. However, these defects were alleviated when melatonin was fed under hypoxia conditions. Together, these findings suggest that hypoxia exposure impaired follicular development and reduced oocyte quality, and that melatonin supplementation alleviated the fertility reduction induced by hypoxia exposure.

Aberrantly High FBXO31 Impairs Oocyte Quality in Premature Ovarian Insufficiency

Premature ovarian insufficiency (POI), which is defined as loss of ovarian function that occurs before the age of 40, causes menstrual disturbances, infertility, and diverse health problems in females. Despite the limited understanding of the molecular basis underlying POI pathology, we had previously demonstrated that the cooperation of miR-106a and FBXO31 plays a pivotal role in diminished ovarian reserve (DOR), with FBXO31 serving as a putative target of miR-106a. In this study, we found that FBXO31 is aberrantly expressed in granulosa cells of POI patients, leading to accumulated reactive oxygen species (ROS) and cell apoptosis via the p53/ROS pathway. Furthermore, our results demonstrated that high levels of FBXO31 in mouse ovaries impair oocyte quality. Our study revealed that FBXO31 may serve as a novel indicator and play a significant role in the etiology of POI.

A matter of new life and cell death: programmed cell death in the mammalian ovary

BACKGROUND

The mammalian ovary is a unique organ that displays a distinctive feature of cyclic changes throughout the entire reproductive period. The estrous/menstrual cycles are associated with drastic functional and morphological rearrangements of ovarian tissue, including follicular development and degeneration, and the formation and subsequent atrophy of the corpus luteum. The flawless execution of these reiterative processes is impossible without the involvement of programmed cell death (PCD).

MAIN TEXT

PCD is crucial for efficient and careful clearance of excessive, depleted, or obsolete ovarian structures for ovarian cycling. Moreover, PCD facilitates selection of high-quality oocytes and formation of the ovarian reserve during embryonic and juvenile development. Disruption of PCD regulation can heavily impact the ovarian functions and is associated with various pathologies, from a moderate decrease in fertility to severe hormonal disturbance, complete loss of reproductive function, and tumorigenesis. This comprehensive review aims to provide updated information on the role of PCD in various processes occurring in normal and pathologic ovaries. Three major events of PCD in the ovary-progenitor germ cell depletion, follicular atresia, and corpus luteum degradation-are described, alongside the detailed information on molecular regulation of these processes, highlighting the contribution of apoptosis, autophagy, necroptosis, and ferroptosis. Ultimately, the current knowledge of PCD aberrations associated with pathologies, such as polycystic ovarian syndrome, premature ovarian insufficiency, and tumors of ovarian origin, is outlined.

CONCLUSION

PCD is an essential element in ovarian development, functions and pathologies. A thorough understanding of molecular mechanisms regulating PCD events is required for future advances in the diagnosis and management of various disorders of the ovary and the female reproductive system in general.

Effects of ferritin heavy chain on oxidative stress, cell proliferation and apoptosis in geese follicular granulosa cells

1. The ferritin heavy chain (FHC) has a vital impact on follicular development in geese, due to its ability to regulate apoptosis of granulosa cells (GCs) and follicular atresia. However, its specific regulatory mechanisms remain unclear. The present study characterised how FHC regulates oxidative stress, cell proliferation and apoptosis in goose GCs by interfering with and overexpressing the FHC gene.2. After 72 h of interference with FHC expression, the activity of GCs decreased remarkably (p < 0.05), reactive oxygen species (ROS) levels and the expression levels of antioxidant enzyme genes catalase (CAT), superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) increased significantly (p < 0.05). The overexpression of FHC for 72 h was found to significantly reduce the expression of CAT and SOD genes (p < 0.05).3. Interfering with FHC expression revealed that the expression levels of the cell proliferation gene Aurora kinase A (AURORA-A) were significantly decreased (p < 0.05), while the expression levels of the apoptosis genes B-cell lymphoma-2 (BCL-2) and cysteine aspartate-specific protease 8 (CASPASE 8) increased (p < 0.05). Further research has shown that, when interfering with FHC expression for 72 h, apoptosis rate increased by 1.19-fold (p < 0.05), but the current data showed a lower apoptosis rate after FHC overexpression by 59.41%, 63.39%, and 52.31% at three different treatment times (p < 0.05).4. In conclusion, FHC improved the antioxidant capacity of GCs, promotes GCs proliferation, and inhibits GCs apoptosis of ovarian follicles in Sichuan white geese.

Efficacy of natural products on premature ovarian failure: a systematic review and meta-analysis of preclinical studies

OBJECTIVE

This study aims to investigate the effects of natural products on animal models of premature ovarian failure (POF).

METHODS

We conducted comprehensive literature searches and identified relevant studies that examined the protective effects of natural products on experimental POF. We extracted quantitative data on various aspects such as follicular development, ovarian function, physical indicators, oxidative stress markers, inflammatory factors, and protein changes. The data was analyzed using random-effects meta-analyses, calculating pooled standardized mean differences and 95% confidence intervals. Heterogeneity was assessed using the I2 statistic, and bias was estimated using the SYRCLE tool.

RESULTS

Among the 879 reviewed records, 25 articles met our inclusion criteria. These findings demonstrate that treatment with different phytochemicals and marine natural products (flavonoids, phenols, peptides, and alkaloids, etc.) significantly improved various aspects of ovarian function compared to control groups. The treatment led to an increase in follicle count at different stages, elevated levels of key hormones, and a decrease in atretic follicles and hormone levels associated with POF. This therapy also reduced oxidative stress (specifically polyphenols, resveratrol) and apoptotic cell death (particularly flavonoids, chrysin) in ovarian granulosa cells, although it showed no significant impact on inflammatory responses. The certainty of evidence supporting these findings ranged from low to moderate.

CONCLUSIONS

Phytochemicals and marine natural product therapy (explicitly flavonoids, phenols, peptides, and alkaloids) has shown potential in enhancing folliculogenesis and improving ovarian function in animal models of POF. These findings provide promising strategies to protect ovarian reserve and reproductive health. Targeting oxidative stress and apoptosis pathways may be the underlying mechanism.

Mulberry Leaf Polysaccharides Attenuate Oxidative Stress Injury in Peripheral Blood Leukocytes by Regulating Endoplasmic Reticulum Stress

The present study assessed the protective effects and underlying mechanisms of mulberry leaf polysaccharides (MLPs) against hydrogen peroxide (H2O2)-induced oxidative stress injury in the peripheral blood leukocytes (PBLs) of Megalobrama amblycephala. Five treatment groups were established in vitro: the NC group (PBLs incubated in an RPMI-1640 complete medium for 4 h), the HP group (PBLs incubated in an RPMI-1640 complete medium for 3 h, and then stimulated with 100 μM of H2O2 for 1 h), and the 50/100/200-MLP pre-treatment groups (PBLs were pre-treated with MLPs (50, 100, and 200 μg/mL) for 3 h, and then stimulated with 100 μM of H2O2 for 1 h). The results showed that MLP pre-treatment dose-dependently enhanced PBLs' antioxidant capacities. The 200 μg/mL MLP pre-treatment effectively protected the antioxidant system of PBLs from H2O2-induced oxidative damage by reducing the malondialdehyde content and lactic dehydrogenase cytotoxicity, and increasing catalase and superoxide dismutase activities (p < 0.05). The over-production of reactive oxygen species, depletion of nicotinamide adenine dinucleotide phosphate, and collapse of the mitochondrial membrane potential were significantly inhibited in the 200-MLP pre-treatment group (p < 0.05). The expressions of endoplasmic reticulum stress-related genes (forkhead box O1α (foxO1α), binding immunoglobulin protein (bip), activating transcription factor 6 (atf6), and C/EBP-homologous protein (chop)), Ca2+ transport-related genes (voltage-dependent anion-selective channel 1 (vdac1), mitofusin 2 (mfn2), and mitochondrial Ca2+ uniporter (mcu)), and interleukin 6 (il-6) and bcl2-associated x (bax) were significantly lower in the 200-MLP pre-treatment group than in the HP group (p < 0.05), which rebounded to normal levels in the NC group (p > 0.05). These results indicated that MLP pre-treatment attenuated H2O2-induced PBL oxidative damage in the M. amblycephala by inhibiting endoplasmic reticulum stress and maintaining mitochondrial function. These findings also support the possibility that MLPs can be exploited as a natural dietary supplement for M. amblycephala, as they protect against oxidative damage.

The multiple actions of grape and its polyphenols on female reproductive processes with an emphasis on cell signalling

Grapes are an economically important fruit crop, and their polyphenols (mainly phenolic acids, flavanols, flavonols, anthocyanins, proanthocyanidins, and stilbenes) can exert a wide range of health benefits as an interesting and valuable dietary supplement for natural complementary therapy. However, their potential physiological and therapeutic actions on reproductive processes have not been sufficiently elucidated. This evidence-based study presents current knowledge of grape extracts and polyphenols, as well as their properties and therapeutical actions in relation to female reproduction in a nutshell. Grape extract, and its polyphenols such as resveratrol, proanthocyanidin B2 or delphinidin may influence female reproductive physiology and pathology, as well as regulate multiple signaling pathways related to reproductive hormones, steroid hormones receptors, intracellular regulators of oxidative stress and subsequent inflammation, apoptosis, and proliferation. Their role in the management of ovarian cancer, age-related reproductive insufficiency, ovarian ischemia, PCOS, or menopausal syndrome has been indicated. In particular, the potential involvement of grapeseed extracts and/or proanthocyanidin B2 and delphinidin on ovarian steroidogenesis, oocyte maturation, and developmental capacity has been implicated, albeit at different regulatory levels. Grape polyphenols exert a wide range of health benefits posing grape extract as an interesting and valuable dietary supplement for natural complementary therapy. This evidence-based study focuses on the actions of grapeseed extract and grape polyphenols on female reproductive processes at various regulatory levels and multiple signalling pathways by regulating reproductive hormones (GnRH, gonadotropins, prolactin, steroid hormones, IGFBP), steroid receptors, markers of proliferation and apoptosis. However, lack of knowledge of standardized dosages so far limits their clinical application despite the wide range of their biological and therapeutic potentials.

MicroRNA-129-1-3p protects chicken granulosa cells from cadmium-induced apoptosis by down-regulating the MCU-mediated Ca2+ signaling pathway

Cadmium (Cd) is known as a female reproductive toxicant. Our previous study has shown that Cd can influence the proliferation and cell cycle of granulosa cells and induce apoptosis. MicroRNAs (miRNAs) play an important role in the regulation of Cd-induced granulosa cell damage in chickens. However, the mechanism remains unclear. In this study, we investigated the mechanisms by which microRNA-129-1-3p (miR-129-1-3p) regulates Cd-induced cytotoxicity in chicken granulosa cells. As anticipated, exposure to Cd resulted in the induction of oxidative stress in granulosa cells, accompanied by the downregulation of antioxidant molecules and/or enzymes of Nrf2, Mn-SOD, Cu-Zn SOD and CAT, and the upregulation of Keap1, GST, GSH-Px, GCLM, MDA, hydrogen peroxide and mitochondrial reactive oxygen species (mtROS). Further studies found that Cd exposure causes mitochondrial calcium ions (Ca2+) overload, provoking mitochondrial damage and apoptosis by upregulating IP3R, GRP75, VDAC1, MCU, CALM1, MFF, caspase 3, and caspase 9 gene and/or protein expressions and mitochondrial Ca2+ levels, while downregulating NCX1, NCLX and MFN2 gene and/or protein expressions and mitochondrial membrane potential (MMP). The Ca2+ chelator BAPTA-AM or the MCU inhibitor MCU-i4 significantly rescued Cd-induced mitochondrial dysfunction, thereby attenuating apoptosis. Additionally, a luciferase reported assay and western blot analysis confirmed that miR-129-1-3p directly target MCU. MiR-129-1-3p overexpression almost completely inhibited protein expression of MCU, increased the gene and protein expressions of NCLX and MFN2 downregulated by Cd, and attenuated mitochondrial Ca2+ overload, MMP depression and mitochondria damage induced by Cd. Moreover, the overexpression of miR-129-1-3p led to a reduction in mtROS and cell apoptosis levels, and a suppression of the gene and protein expressions of caspase 3 and caspase 9. As above, these results provided the evidence that IP3R-MCU signaling pathway activated by Cd plays a significant role in inducing mitochondrial Ca2+ overload, mitochondrial damage, and apoptosis. MiR-129-1-3p exerts a protective effect against Cd-induced granulosa cell apoptosis through the direct inhibition of MCU expression in the ovary of laying hens.

Perfluorooctanoic acid exposure leads to defect in follicular development through disrupting the mitochondrial electron transport chain in granulosa cells

Perfluorooctanoic acid (PFOA) is a persistent environmental pollutant that can impair ovarian function, while the underlying mechanism is not fully understood, and effective treatments are lacking. In this study, we established a mouse model of PFOA exposure induced by drinking water and found that PFOA exposure impaired follicle development, increased apoptosis of granulosa cells (GCs), and hindered normal follicular development in a 3D culture system. RNA-seq analysis revealed that PFOA disrupted oxidative phosphorylation in ovaries by impairing the mitochondrial electron transport chain. This resulted in reduced mitochondrial membrane potential and increased mitochondrial reactive oxygen species (mtROS) in isolated GCs or KGN cells. Resveratrol, a mitochondrial nutrient supplement, could improve mitochondrial function and restore normal follicular development by activating FoxO1 through SIRT1/PI3K-AKT pathway. Our results indicate that PFOA exposure impairs mitochondrial function in GCs and affects follicle development. Resveratrol can be a potential therapeutic agent for PFOA-induced ovarian dysfunction.

Oocyte quality is impaired in a hyperandrogenic PCOS mouse model by increased Foxo1 expression

One of the most important characteristics of patients with polycystic ovary syndrome (PCOS) is excess androgen, which has adverse effects on pregnancy outcomes and increases the risk of offspring developing metabolic disorders. Foxo1 has been shown to play an important role in PCOS, but whether it has an affect on oocyte's quality in PCOS remains unclear. The current research investigated the effect of excess androgen exposure on mouse oocyte quality, as well as the possible molecular mechanism. Timelapse incubator was used to culture oocytes in vitro and evaluate the maturation process. The level of reactive oxygen species (ROS) and mitochondrial membrane potential were detected by laser confocal microscope. Immunofluorescence staining assays were performed to examine the expression of Foxo1 and γ-H2AX. Relative mRNA level of Foxo1 and Caspase3 were examined by RT-qPCR. Results showed Germinal vesicle breakdown and maturation rates of oocytes from hyperandrogenic PCOS mice were significantly decreased in vitro, while in vitro maturation showed a marked delay from the germinal vesicle breakdown to metaphase II stage in PCOS group. Expression levels of reactive oxygen species, Foxo1, Caspase3, and γ-H2AX were significantly increased, whereas mitochondrial membrane potential was significantly decreased in oocytes from PCOS mice. These results indicate that excess androgen exposure induced oxidative stress, which further induced high expression of Foxo1, resulting in more DNA damage and apoptosis in oocytes. The current findings provide new knowledge for exploring the mechanism of decreased oocyte quality in hyperandrogenic PCOS.

Fetal hypoxia expose caused autophagy in ovary granulosa cells via PI3K/Akt/FoxO1 pathway and mitigated by melatonin subheading

INTRODUCTION

Fetal hypoxia has long-term effects on postnatal reproductive functions and the mitochondrial impairments of ovarian granulosa cells may be one of the causes. Melatonin applied to mitigate mitochondrial dysfunction and autophagy in mammalian cells has been reported. However, the potential mechanisms by which fetal hypoxia damages reproductive function in neonatal female mice and the melatonin effects on this problem remain unclear.

OBJECTIVES

This research aimed to explore the mechanism that fetal hypoxia damages reproductive function in neonatal female mice and attempt to improve the reproductive function by treating with melatonin in vivo and in vitro.

METHODS

We established a fetal hypoxia model and confirmed that fetal hypoxia affects ovarian function by inducing GC excessive autophagy. Transcriptomic analysis, gene interference, cell immunofluorescence, immunohistochemistry and western blot were conducted to explore and verify the underlying mechanisms in mice GCs and KGN cells. Finally, melatonin treatment was executed on hypoxia-treated mice GCs and KGN cells and melatonin injection to fetal-hypoxia-treated mice to determine its effect.

RESULTS

The results of in vitro experiments found that fetal hypoxia led to mitochondrial dysfunction in ovarian GCs causing autophagic cell death. And the PI3K/Akt/FoxO pathway mediated the occurrence of this process by transcriptome analysis of ovarian GCs from normal and fetal hypoxia mice, which was further verified in mice GCs and KGN cells. Additionally, melatonin administration prevented autophagic injuries and mitochondrial impairments in hypoxia-treated mice GCs and KGN cells. Meanwhile, in vivo experiments by melatonin injection ameliorated oxidative stress of ovary in fetal-hypoxia-treated mice and improved their low fertility.

CONCLUSION

Our data found that fetal hypoxia causes ovarian GCs excessive autophagy leading to low fertility in neonatal female mice and mitigated by melatonin. These results provide a potential therapy for hypoxic stress-related reproductive disorders.

FSHR-mTOR-HIF1 signaling alleviates mouse follicles from AMPK-induced atresia

The majority of activated ovarian follicles undergo atresia during reproductive life in mammals, and only a small number of follicles are ovulated. Though hormone treatment has been widely used to promote folliculogenesis, the molecular mechanism behind follicle selection and atresia remains under debate due to inconsistency among investigation models. Using a high-throughput molecular pathology strategy, we depicted a transcriptional atlas of mouse follicular granulosa cells (GCs) under physiological condition and obtained molecular signatures in healthy and atresia GCs during development. Functional results revealed hypoxia-inducible factor 1 (HIF1) as a major effector downstream of follicle-stimulating hormone (FSH), and HIF1 activation is essential for follicle growth. Energy shortage leads to prevalent AMP-activated protein kinase (AMPK) activation and drives follicular atresia. FSHR-mTOR-HIF1 signaling helps follicles escape from the atresia fate, while energy stress persists. Our work provides a comprehensive understanding of the molecular network behind follicle selection and atresia under physiological condition.

Human umbilical cord mesenchymal stem cell‑derived exosomes improve ovarian function in natural aging by inhibiting apoptosis

Prolonging the reproductive lifespan is beneficial for preserving the physical and psychological health of women. The transplantation of mesenchymal stem cell (MSC)‑derived exosomes (MSC‑Exos) has been reported to be a promising regenerative therapeutic strategy for restoring the function of aging ovaries. The present study thus evaluated the therapeutic efficacy of exosomes derived from human umbilical cord‑MSCs (hUCMSC‑Exos) in a mouse model of natural ovarian aging (NOA), and further investigated the role of exosomal microRNAs (miRNAs/miRs) in the mechanisms of this creative therapy. Specifically, following the administration of hUCMSC‑Exos in mice with NOA, ovarian function was found to improve, as indicated by the restoration of follicle numbers and hormone levels. These exosomes were found to exhibit the ability to inhibit PTEN expression and suppress apoptosis both in vivo and in vitro. Subsequently, miRNA sequencing of the exosomes was performed, following which bioinformatics analysis was used to identify the highly expressed miRNAs that are capable of targeting PTEN expression. Through high‑throughput sequencing and molecular analyses, miR‑21‑5p was found to be the highest in ranking in terms of expression, suggesting that hUCMSC‑Exos can preserve ovarian function by suppressing PTEN expression to inhibit apoptosis by delivering miR‑21‑5p. On the whole, the results of the present study suggest that the application of exosomes can be used to restore ovarian function in mice with NOA. These positive findings also suggest that the transplantation of exosomes derived from MSCs holds promise as an agent against ovarian aging.

Krüppel-like factor 12 regulates aging ovarian granulosa cell apoptosis by repressing SPHK1 transcription and sphingosine-1-phosphate (S1P) production

Oxidative stress triggered by aging, radiation, or inflammation impairs ovarian function by inducing granulosa cell (GC) apoptosis. However, the mechanism inducing GC apoptosis has not been characterized. Here, we found that ovarian GCs from aging patients showed increased oxidative stress, enhanced reactive oxygen species activity, and significantly decreased expression of the known antiapoptotic factor sphingosine-1-phosphate/sphingosine kinase 1 (SPHK1) in GCs. Interestingly, the expression of Krüppel-like factor 12 (KLF12) was significantly increased in the ovarian GCs of aging patients. Furthermore, we determined that KLF12 was significantly upregulated in hydrogen peroxide-treated GCs and a 3-nitropropionic acid-induced in vivo model of ovarian oxidative stress. This phenotype was further confirmed to result from inhibition of SPHK1 by KLF12. Interestingly, when endogenous KLF12 was knocked down, it rescued oxidative stress-induced apoptosis. Meanwhile, supplementation with SPHK1 partially reversed oxidative stress-induced apoptosis. However, this function was lost in SPHK1 with deletion of the binding region to the KLF12 promoter. SPHK1 reversed apoptosis caused by hydrogen peroxide-KLF12 overexpression, a result further confirmed in an in vitro ovarian culture model and an in vivo 3-nitropropionic acid-induced ovarian oxidative stress model. Overall, our study reveals that KLF12 is involved in regulating apoptosis induced by oxidative stress in aging ovarian GCs and that sphingosine-1-phosphate/SPHK1 can rescue GC apoptosis by interacting with KLF12 in negative feedback.

Moringa oleifera leaf supplementation relieves oxidative stress and regulates intestinal flora to ameliorate polycystic ovary syndrome in letrozole-induced rats

This study investigated the effects of supplementation Moringa oleifera leaf (MOL) on relieving oxidative stress, anti-inflammation, changed the relative abundance of multiple intestinal flora and blood biochemical indices during letrozole-induced polycystic ovary syndrome (PCOS). Previous studies have shown that MOL has anti-inflammatory, anti-oxidation, insulin-sensitizing effects. However, whether MOL has beneficial effects on PCOS remains to be elucidated. In the current study, 10-week-old female Sprague-Dawley rats received letrozole to induce PCOS-like rats, and subsequently were treated with a MOL diet. Then, the body weight and estrus cycles were measured regularly in this period. Finally, the ovarian morphology, blood biochemical indices, anti-oxidative, intestinal flora, and anti-inflammation were observed at the end of the experiment. We found that MOL supplementation markedly decreased the body weight, significantly upregulated the expression of Sirt1, FoxO1, PGC-1α, IGF1, and substantially modulated the sex hormone level and improved insulin resistance, which may be associated with the relieves oxidative stress. Moreover, the supplementation of MOL changed the relative abundance of multiple intestinal flora, the relative abundance of Fusobacterium, Prevotella were decreased, and Blautia and Parabacteroides were increased. These results indicate that MOL is potentially a supplementary medication for the management of PCOS.

Treatment of porcine ovarian follicles with tert-butyl hydroperoxide as an ovarian senescence model in vitro

Ovarian aging is the main reason of female reproductive problems. Excessive oxidative stress can induce ovarian senescence and follicular atresia, thereby reducing the reproductive performance. Follicles were divided into five groups for in vitro culture based on the duration of stimulation with tert-butyl hydroperoxide (t-BHP)-control group and groups 1 h, 2 h, 6 h, and 12 h. The results revealed that the ratio of progesterone (P4) to estradiol (E2) was increased after 24 and 36 h of follicle culture, shifting follicles toward atresia (P < 0.05). Stimulated by 200 μM t-BHP, follicles showed progressive aging phenotype. Senescence-associated β-galactosidase staining (SA-β-Gal) showed a significant increase in the number of positive cells (P < 0.05). Reactive oxygen species were also significantly upregulated (P < 0.05). t-BHP treatment for 6 h induced significant increases in Caspase 3, P53, and Foxo1 mRNA and protein levels (P < 0.05) and significant decreases in SOD mRNA and protein levels (P < 0.05). Transcriptome sequencing analysis of the follicles showed that the aged and treatment groups were clustered together in hierarchical clustering. Correlation analysis indicated significant changes at the transcriptome level in the treatment groups versus the control group. The common differentially expressed genes in the treatment groups were enriched in three growth-factor signaling pathways associated with cell proliferation and apoptosis (P53, mTOR, and MAPK). In conclusion, induction of follicular senescence by treatment with 200 μM t-BHP for 6 h is an effective in vitro model to simulate ovarian senescence in sows.

Reproductive and metabolic toxic effects of polystyrene microplastics in adult female Wistar rats: a mechanistic study

Microplastics, such as polystyrene microplastics (PS-MPs), have become an emerging environmental hazard for animals and humans. Long-term exposure to PS-MPs has led to neurotoxicity, reproductive dysfunction, and carcinogenesis. The goal of this study was to evaluate the effect of sub-chronic exposure of PS-MPs on metabolic and reproductive functions in female rats. The PS-MPs were prepared by cryogenic technique. The PS-MPs were given orally to female Wistar rats for 45 days at 2.5, 5, and 10 mg/kg/day. The average PS-MPs' size diameter was 876 nm. The PS-MPs administration resulted in a significant decrease in the activity of superoxide dismutase and catalase in the liver and ovary. The effect of PS-MPs on reduced glutathione and lipid peroxidation in the liver and ovarian tissues of rats was statistically insignificant. The PS-MP exposure exhibited an increase in the levels of triglycerides, total cholesterol, and low-density lipoprotein and decrease in high-density lipoprotein. The PS-MPs caused glucose intolerance and increase in insulin. Moreover, the PS-MP exposure increased follicle stimulating hormone, estradiol, and testosterone. Serum level of interleukin-6 and nuclear factor kappa B (NF-κB) was elevated in animals treated with PS-MPs. The PS-MP exposed rats showed normal ovarian histology, but activated hepatic stellate cells and liver fibrosis. It is concluded that the sub-chronic exposure to PS-MPs resulted in metabolic and endocrine disruption in female rats through oxidative damage, hormonal imbalance, and chronic inflammation.

The protective effect of resveratrol on largemouth bass (Micropterus salmoides) during out-of-season spawning

In aquaculture production, out-of-season spawning is beneficial to solve the seasonal shortage of fry that are normally produced once annually by species such as largemouth bass (Micropterus salmoides), thereby implementing year-round fry production. Maintaining low temperature over a period of several months can delay largemouth bass ovarian development, but it can cause severe stress to their reproductive function, leading to decreased fertility during out-of-season spawning. Feeding with antioxidants is one of the most effective methods to alleviate the negative effects of low temperature stress. Therefore, the purpose of this study is to: (a) evaluate the changes in oocyte morphology, antioxidant capacity, reproductive hormone-related index, cell apoptosis and autophagy during the out-of-season spawning of largemouth bass, and (b) to investigate the protective effect of the antioxidant resveratrol on this fish during out-of-season spawning from May through August. The study was divided into two groups (three replicates per group, 2000 fish per replicate): control group (Control) (exposure to water temperature of 12-17 °C) and resveratrol supplementation group (Res) (exposure to water temperature of 12-17 °C and fed with 200 mg/kg resveratrol). The results show that: (1) The serum hormones LH and E2 increased first and then remained unchanged, and the ovarian section showed that the ovary remained in stage IV. (2) In the process of off-season reproduction, a large number of follicles experienced follicular atresia, accompanied by endoplasmic reticulum expansion, nuclear chromatin condensation and mitochondrial swelling, which was relieved after feeding resveratrol. (3) Resveratrol decreased the ovarian ROS content and improved the activities of CAT and other antioxidant enzymes in the ovary and liver to some extent. (4) Resveratrol reduced the level of pro-apoptotic (Bax, Caspase3, Caspase8, Caspase9) and autophagy-related components (LC3-B, Beclin-1) while increasing the transcription level of anti-apoptotic (Bcl-2) factors. These findings suggest that resveratrol alleviates some adverse effects of largemouth bass during out-of-season spawning to some extent and provide a model for efficient and high-quality out-of-season spawning.

Melatonin alleviates ovarian function damage and oxidative stress induced by dexamethasone in the laying hens through FOXO1 signaling pathway

Oxidative stress can trigger follicular atresia, and decrease follicles quantity in each development stage, thereby alleviating reproductive activity. The induction of oxidative stress in chickens through intraperitoneal injection of dexamethasone is a reliable and stable method. Melatonin has been shown to mitigate oxidative stress in this model, but the underlying mechanism remains unclear. Therefore, this study aimed to investigate whether melatonin can recover aberrant antioxidant status induced by dexamethasone and the specific mechanism behind melatonin-dependent protection. A total of 150 healthy 40-wk-old Dawu Jinfeng laying hens with similar body weights and laying rates were randomly divided into three groups, with five replicates per group and 10 hens per replicate. The hens in the control group (NS) received intraperitoneal injections of normal saline for 30 d, the dexamethasone group (Dex+NS) received 20 mg/kg dose of dexamethasone for the first 15 d, followed by the 15 d of normal saline treatment. While in the melatonin group (Dex+Mel), dexamethasone (20 mg/kg dose) was injected intraperitoneally in the first 15 d, and melatonin (20 mg/kg/d) was injected in the last 15 d. The results showed that dexamethasone treatment significantly enhanced oxidative stress (P < 0.05), while melatonin not only inhibited the oxidative stress but also notably enhanced the antioxidant enzymes superoxide dismutase (SOD), catalase activity (CAT), glutathione peroxidase (GSH-Px), and antioxidant genes CAT, superoxide dismutase 1 (SOD1), glutathione peroxidase 3 (GPX3), and recombinant peroxiredoxin 3 (PRDX3) expression (P < 0.05). Melatonin treatment also markedly reduced 8-hydroxy deoxyguanosine (8-OHdG), malondialdehyde (MDA), and reactive oxygen species (ROS) levels (P < 0.05) and apoptotic genes Caspase-3, Bim, and Bax in the follicle. In the Dex+Mel group, the Bcl-2 and SOD1 protein levels were also increased (P < 0.05). Melatonin inhibited the forkhead Box Protein O1 (FOXO1) gene and its protein expression (P < 0.05). In general, this investigation revealed that melatonin might decrease oxidative stress and ROS by enhancing antioxidant enzymes and genes, activating the antiapoptotic genes, and inhibiting the FOXO1 pathway in laying hens.

Integrative analysis of transcriptomic and metabolomic profiles reveals abnormal phosphatidylinositol metabolism in follicles from endometriosis‐associated infertility patients

Endometriosis is a common gynecological disorder that causes female infertility. Our recent research found that excessive oxidative stress in ovaries of endometriosis patients induced senescence of cumulus granulosa cells. Here, we analyzed the transcriptomic and metabolomics profiles of follicles in a mouse model of endometriosis and in patients with endometriosis and investigated the potential function of changed metabolites in granulosa cells. RNA-sequencing indicated that both endometriosis lesions and oxidative stress in mice induced abnormalities of reactive oxidative stress, steroid hormone biosynthesis, and lipid metabolism. The mouse model and women with endometriosis showed altered lipid metabolism. Nontargeted metabolite profiling of follicular fluid from endometriosis and male-factor infertility patients by liquid chromatography mass spectrometry identified 55 upregulated and 67 downregulated metabolites. These differential metabolites were mainly involved in steroid hormone biosynthesis and glycerophospholipid metabolism. Phosphatidylinositol (PI 16:0/18:2) was significantly elevated in follicular fluid from endometriosis patients compared with controls (p < 0.05), while lysophosphatidylinositol (LPI 18:2, 20:2, 18:1, 20:3 and 18:3) was reduced (p < 0.05). Upregulated PI and downregulated LPI correlated with oocyte retrieval number and mature oocyte number. LPI inhibited cellular reactive oxidative stress induced by hemin in granulosa cells. Cell proliferation inhibition, senescence, and apoptosis induced by hemin were partially reversed by LPI. Moreover, LPI administration rescued hemin blocking of cumulus-oocyte complex expansion and stimulated expression of ovulation-related genes. Transcriptomic Switching mechanism at 5' end of the RNA transcript sequencing and western blot revealed that LPI effects on granulosa cells were associated with its regulation of MAPK-ERK1/2 signaling, which was suppressed in the presence of hemin. In conclusion, our results revealed the dysregulation of lipid metabolism in endometriotic follicles. LPI may represent a novel agent for in vitro follicular culture that reverses the excessive oxidative stress from endometriotic lesions. © 2023 The Authors. The Journal of Pathology published by John Wiley & Sons Ltd on behalf of The Pathological Society of Great Britain and Ireland.

Erxian decoction alleviates cisplatin-induced premature ovarian failure in rats by reducing oxidation levels in ovarian granulosa cells

ETHNOPHARMACOLOGICAL RELEVANT

Erxian Decoction (EXD) has been used empirically for more than 70 years to treat premature ovarian failure (POF), but more research is needed to understand how it works.

AIM OF THE RESEARCH

The study aims to ascertain both in vivo and in vitro rewards of EXD.

MATERIALS AND METHODS

EXD is composed of Curculiginis Rhizoma, Epimedii Folium, Morindae Officinalis, Angelicae Sinensis, Anemarrhenae Rhizoma, and Phellodendri Chinensis Cortex. UPLC/MS analysis was used to investigate the components of EXD. Using a POF model created by administering cisplatin to rats intraperitoneally, the pharmacodynamic effects of EXD were investigated. Three dose groups of EXD were garaged into rats: high (15.6 g/kg), medium (7.8 g/kg), and low (3.9 g/kg). By using a vaginal smear, the impact of EXD on the rat estrous cycle was evaluated. An ELISA test was used to measure the anti-Mullerian hormone (AMH), estradiol (E2), follicle-stimulating hormone (FSH), and luteinizing hormone (LH) levels in the serum of rats. By using HE stains, pathological alterations in the ovaries may be seen. MDA and SOD levels in ovarian samples were used to measure the degree of ovarian oxidation. TUNEL labeling of ovarian sections was used to find apoptosis levels. By using ATP, energy production was evaluated. The relative expression of proteins connected to aging and the RAGE pathway was assessed using Western blot. Then, using H₂O₂, a model of senescent human ovarian granulosa cells (KGN) was created in vitro. The impact of EXD and H₂O₂ on cellular senescence was discovered using-galactosidase staining. Cell apoptosis levels were found using PI/Hoechest33342. By using DCFH-DA, intracellular ROS was examined. MDA and SOD concentrations were used to measure the degree of cellular oxidation. RAGE-related mRNA and protein expression were evaluated using RT-qPCR and western blotting.

RESULTS

Using UPLC/MS analysis, 39 chemicals in EXD were found. Rats' estrous cycles were enhanced by EXD, which increased ovarian index and follicle count and reduced the proportion of atretic follicles in the rats. EXD reduced LH and FSH output while restoring AMH and E2 secretion. In ovarian tissues, EXD reduced the amount of apoptosis and MDA while raising SOD activity and ATP levels. The protein levels of p16, p21, p53, and Lamin A/C were among the senescence-related proteins that EXD lowered, along with the levels of RAGE, PI3K, BAX, and CASPASE 3. Anti-apoptotic protein BCL-2 was also raised in the RAGE pathway. Senescence, apoptosis, ROS, and MDA levels in the KGN cells were lowered in vitro by EXD. Additionally, EXD increased the anti-apoptotic potential by changing the expression of CAT, SOD2, and SIRT1. RAGE, BAX, BCL-2, CASPASE 3, and p38 expression levels were altered by EXD, enhancing its anti-apoptotic capability.

CONCLUSION

EXD boosted the ovary's antioxidant and anti-apoptotic capabilities while enhancing the estrous cycle and hormone output. These findings strongly suggested that EXD may contribute to the alleviation of POF and ovarian granulosa cells senescence.

Dietary supplementation of coated sodium butyrate improves growth performance of laying ducks by regulating intestinal health and immunological performance

Introduction

This study was conducted to assess the effects of dietary supplementation of coated sodium butyrate (CSB) on the growth performance, serum antioxidant, immune performance, and intestinal microbiota of laying ducks.

Methods

A total of 120 48-week-old laying ducks were randomly divided into 2 treatment groups: the control group (group C fed a basal diet) and the CSB-treated group (group CSB fed the basal diet + 250 g/t of CSB). Each treatment consisted of 6 replicates, with 10 ducks per replicate, and the trial was conducted for 60 days.

Results

Compared with the group C, the group CSB showed a significant increase in the laying rate (p&lt;0.05) of the 53-56 week-old ducks. Additionally, the serum total antioxidant capacity, superoxide dismutase activity and immunoglobulin G level were significantly higher (p&lt;0.05), while the serum malondialdehyde content and tumor necrosis factor (TNF)-a level were significantly lower (p&lt;0.05) in the serum of the group CSB compared to the group C. Moreover, the expression of IL-1b and TNF-a in the spleen of the group CSB was significantly lower (p&lt;0.05) compared to that of the group C. In addition, compared with the group C, the expression of Occludin in the ileum and the villus height in the jejunum were significantly higher in the group CSB (p&lt;0.05). Furthermore, Chao1, Shannon, and Pielou-e indices were higher in the group CSB compared to the group C (p&lt;0.05). The abundance of Bacteroidetes in the group CSB was lower than that in the group C (p&lt;0.05), while the abundances of Firmicutes and Actinobacteria were higher in the group CSB compared to the group C (p&lt;0.05).

Conclusions

Our results suggest that the dietary supplementation of CSB can alleviate egg-laying stress in laying ducks by enhancing immunity and maintaining the intestinal health of the ducks.

Non-Esterified Fatty Acid-Induced Apoptosis in Bovine Granulosa Cells via ROS-Activated PI3K/AKT/FoxO1 Pathway

Non-esterified fatty acid (NEFA), one of negative energy balance (NEB)'s most well-known products, has a significant impact on cows' reproductive potential. Our study used an in vitro model to investigate the deleterious effects of NEFA on bovine granulosa cells (BGCs) and its underlying molecular mechanism. The results showed that high levels of NEFA led to the accumulation of reactive oxygen species (ROS), increased the expression of apoptosis-related factors such as Bcl2-Associated X/B-cell lymphoma-2 (Bax/Bcl-2) and Caspase-3, and down-regulated steroid synthesis-related genes such as sterol regulatory element binding protein 1 (SREBP-1), cytochrome P450c17 (CYP17), and cytochrome P450 aromatase (CYP19), to promote oxidative stress, cell apoptosis, and steroid hormone synthesis disorders in BGCs. In addition, NEFA significantly inhibited phosphatidylinositol 3-kinase (PI3K) and phosphorylated protein kinase B (p-AKT) activity and increased forkhead box O1 (FoxO1) expression. To further explore the role of the PI3K/AKT/FoxO1 signaling pathway in NEFA, we found that pretreatment with AKT-specific activator SC79 (5 mg/mL) for 2 h or transfection with FoxO1 knockdown siRNA in BGCs could alleviate the negative effects of NEFA treatment by decreasing Bax/Bcl-2 ratio and Caspase-3 expression, and upregulating SREBP-1, CYP17, and CYP19 expression. Meanwhile, SC79 significantly inhibited NEFA-induced dephosphorylation and massive nuclear translocation of FoxO1. Taken together, the NEFA induced oxidative stress, apoptosis, and steroid hormone synthesis disorders in BGCs by inhibiting the PI3K/AKT pathway that regulates FoxO1 phosphorylation and nuclear translocation. Our findings help to clarify the molecular mechanisms underlying the negative effects of high levels of NEFA on BGCs.

Repeated Superovulation Accelerates Primordial Follicle Activation and Atresia

For humans, ARTs (assisted reproductive technologies) have become the most effective method to treat subfertility/infertility in clinic. To obtain enough oocytes during ART, ovarian stimulation is performed by exogenous hormones, and some patients undergo several ovarian stimulation cycles. Although some adverse effects of ARTs on women and offspring are reported, few studies are focused on the effects of multiple superovulation on ovarian reserve. In the present study, we found that repeated superovulation significantly reduced primordial follicle number and the serum AMH. Compared to the decreased antral follicle number, the expression of genes related to primordial follicle activation, such as Foxo3, Akt, and Rptor, and the atretic follicle number in ovaries were increased by superovulation times. We further found that repeated superovulation reduced the plasma level of FSH, LH, and estradiol, and increased the expression of genes related to apoptosis (Bax, Casp3 (caspase-3), Casp8, and Casp9) in granulosa cells, providing evidence that repeated superovulation disrupted the balance between survival and death in granulosa cells. In summary, our results suggest that repeated superovulation has adverse effects on folliculogenesis.

Carbohydrate intake in recovery from aerobic exercise differentiates skeletal muscle microRNA expression

Posttranscriptional regulation by microRNA (miRNA) facilitates exercise and diet-induced skeletal muscle adaptations. However, the impact of diet on miRNA expression during postexercise recovery remains unclear. The objective of this study was to examine the effects of consuming carbohydrate or a nutrient-free control on skeletal muscle miRNA expression during 3 h of recovery from aerobic exercise. Using a randomized, crossover design, seven men (means ± SD, age: 21 ± 3 yr; body mass: 83 ± 13 kg; V̇o2peak: 43 ± 2 mL/kg/min) completed two-cycle ergometry glycogen depletion trials followed by 3 h of recovery while consuming either carbohydrate (CHO: 1 g/kg/h) or control (CON: nutrient free). Muscle biopsy samples were obtained under resting fasted conditions at baseline and at the end of the 3-h recovery (REC) period. miRNA expression was determined using unbiased RT-qPCR microarray analysis. Trials were separated by 7 days. Twenty-five miRNAs were different (P < 0.05) between CHO and CON at REC, with Let7i-5p and miR-195-5p being the most predictive of treatment. In vitro overexpression of Let7i-5p and miR-195-p5 in C2C12 skeletal muscle cells decreased (P < 0.05) the expression of protein breakdown (Foxo1, Trim63, Casp3, and Atf4) genes, ubiquitylation, and protease enzyme activity compared with control. Energy sensing (Prkaa1 and Prkab1) and glycolysis (Gsy1 and Gsk3b) genes were lower (P < 0.05) with Let7i-5p overexpression compared with miR-195-5p and control. Fat metabolism (Cpt1a, Scd1, and Hadha) genes were lower (P < 0.05) in miR-195-5p than in control. These data indicate that consuming CHO after aerobic exercise alters miRNA profiles compared with CON, and these differences may govern mechanisms facilitating muscle recovery.NEW & NOTEWORTHY Results provide novel insight into effects of carbohydrate intake on the expression of skeletal muscle microRNA during early recovery from aerobic exercise and reveal that Let7i-5p and miR-195-5p are important regulators of skeletal muscle protein breakdown to aid in facilitating muscle recovery.

MicroRNAs as immune regulators and biomarkers in tuberculosis

Tuberculosis (TB), which is caused by Mycobacterium tuberculosis (Mtb), is one of the most lethal infectious disease worldwide, and it greatly affects human health. Some diagnostic and therapeutic methods are available to effectively prevent and treat TB; however, only a few systematic studies have described the roles of microRNAs (miRNAs) in TB. Combining multiple clinical datasets and previous studies on Mtb and miRNAs, we state that pathogens can exploit interactions between miRNAs and other biomolecules to avoid host mechanisms of immune-mediated clearance and survive in host cells for a long time. During the interaction between Mtb and host cells, miRNA expression levels are altered, resulting in the changes in the miRNA-mediated regulation of host cell metabolism, inflammatory responses, apoptosis, and autophagy. In addition, differential miRNA expression can be used to distinguish healthy individuals, patients with TB, and patients with latent TB. This review summarizes the roles of miRNAs in immune regulation and their application as biomarkers in TB. These findings could provide new opportunities for the diagnosis and treatment of TB.

The Corticosterone–Glucocorticoid Receptor–AP1/CREB Axis Inhibits the Luteinizing Hormone Receptor Expression in Mouse Granulosa Cells

Under stress conditions, luteinizing hormone (LH)-mediated ovulation is inhibited, resulting in insufficient oocyte production and excretion during follicular development. When the body is stressed, a large amount of corticosterone (CORT) is generated, which will lead to a disorder of the body’s endocrine system and damage to the body. Our previous work showed that CORT can block follicular development in mice. Since LH acts through binding with the luteinizing hormone receptor (Lhcgr), the present study aimed to investigate whether and how corticosterone (CORT) influences Lhcgr expression in mouse ovarian granulosa cells (GCs). For this purpose, three-week-old ICR female mice were injected intraperitoneally with pregnant mare serum gonadotropin (PMSG). In addition, the treatment group was injected with CORT (1 mg/mouse) at intervals of 8 h and the control group was injected with the same volume of methyl sulfoxide (DMSO). GCs were collected at 24 h, 48 h, and 55 h after PMSG injection. For in vitro experiments, the mouse GCs obtained from healthy follicles were treated with CORT alone, or together with inhibitors against the glucocorticoid receptor (Nr3c1). The results showed that the CORT caused a downregulation of Lhcgr expression in GCs, which was accompanied by impaired cell viability. Moreover, the effect of the CORT was mediated by binding to its receptor (Nr3c1) in GCs. Further investigation revealed that Nr3c1 might regulate the transcription of Lhcgr through inhibiting the expression of Lhcgr transcription factors, including AP1 and Creb. Taken together, our findings suggested a possible mechanism of CORT-induced anovulation involving the inhibition of Lhcgr expression in GCs by the CORT–Nr3c1–AP1/Creb axis.

Di-isononyl phthalate induces apoptosis and autophagy of mouse ovarian granulosa cells via oxidative stress

Di-isononyl phthalate (DINP) has been widely utilized in industrial, commercial and medical applications for the past few years. Therefore, more attention should be paid to the toxicity of DINP. DINP can cause damage to female reproductive system; however, the potential mechanism remains to be further investigated. In this study, female mice were orally administered with 0, 2, 20 and 200 mg DINP/kg/day for 14 days. We found that DINP significantly affected the arrangement of granulosa cells in ovarian follicles. In addition, DINP could induce apoptosis, autophagy and oxidative stress of the ovary tissue. Meanwhile, the serum estradiol concentration distinctly decreased in the 20 and 200 mg/kg DINP-treated groups, suggesting that DINP might affect the function of ovarian granulosa cells. Primary mouse ovarian granulosa cells were utilized for further investigation after the cells were treated with 0, 100, 200, 400 μM DINP for 24 h. Similar to the in vivo experiment, DINP could also induce apoptosis and autophagy of ovarian granulosa cells, as well as oxidative stress; while inhibition of oxidative stress by NAC could alleviate DINP-induced apoptosis and autophagy. Furthermore, inhibition of autophagy by 3-MA could also rescue the induction of apoptosis by DINP. Taken together, these results indicated that DINP induced apoptosis and autophagy of mouse ovarian granulosa cells via oxidative stress, and autophagy played a cytotoxic role in DINP-induced apoptosis.

The role of oxidative stress in ovarian aging: a review

Ovarian aging refers to the process by which ovarian function declines until eventual failure. The pathogenesis of ovarian aging is complex and diverse; oxidative stress (OS) is considered to be a key factor. This review focuses on the fact that OS status accelerates the ovarian aging process by promoting apoptosis, inflammation, mitochondrial damage, telomere shortening and biomacromolecular damage. Current evidence suggests that aging, smoking, high-sugar diets, pressure, superovulation, chemotherapeutic agents and industrial pollutants can be factors that accelerate ovarian aging by exacerbating OS status. In addition, we review the role of nuclear factor E2-related factor 2 (Nrf2), Sirtuin (Sirt), mitogen-activated protein kinase (MAPK), protein kinase B (AKT), Forkhead box O (FoxO) and Klotho signaling pathways during the process of ovarian aging. We also explore the role of antioxidant therapies such as melatonin, vitamins, stem cell therapies, antioxidant monomers and Traditional Chinese Medicine (TCM), and investigate the roles of these supplements with respect to the reduction of OS and the improvement of ovarian function. This review provides a rationale for antioxidant therapy to improve ovarian aging.

Downregulation of miR-192 Alleviates Oxidative Stress-Induced Porcine Granulosa Cell Injury by Directly Targeting Acvr2a

Follicular atresia is primarily caused by breakdown to granulosa cells (GCs) due to oxidative stress (OS). MicroRNAs (miRNAs) elicit a defense response against environmental stresses, such as OS, by acting as gene-expression regulators. However, the association between miRNA expression and OS in porcine GCs (PGCs) is unclear. Here, we examined the impact of H₂O₂-mediated OS in PGCs through miRNA-Seq. We identified 22 (14 upregulated and 8 downregulated) and 33 (19 upregulated and 14 downregulated) differentially expressed miRNAs (DEmiRNAs) at 100 μM and 300 μM H₂O₂, respectively, compared with the control group. Among the DEmiRNAs, mi-192 was most induced by H₂O₂-mediated OS, and the downregulation of miR-192 alleviated PGC oxidative injury. The dual-luciferase reporter assay results revealed that miR-192 directly targeted Acvr2a. The Acvr2a level was found to be remarkably decreased after OS. Furthermore, grape seed procyanidin B2 (GSPB2) treatment significantly reduced the H₂O₂-induced upregulation of miR-192, and decreased PGC apoptosis and oxidative damage. Meanwhile, GSPB2 prevented an H₂O₂-induced increase in caspase-3 activity, which was enhanced by the application of the miR-192 inhibitor. These results indicate that GSPB2 protects against PGC oxidative injury via the downregulation of miR-192, the upregulation of Acvr2a expression, and the suppression of the caspase-3 apoptotic signaling pathway.

MMP-12 polarizes neutrophil signalome towards an apoptotic signature

While macrophages are well-known to polarize across the inflammatory spectrum, neutrophils have only recently been found to activate in a similar fashion in response to pro- or anti-inflammatory stimuli. Matrix metalloproteinase (MMP)-12 mediates neutrophil physiology with direct signaling mechanisms yet to be investigated. We hypothesized MMP-12 may modify neutrophil signaling. Bone marrow neutrophils were stimulated with interleukin (IL-1β; pro-inflammatory), IL-4 (anti-inflammatory), or MMP-12. The secretome was mapped by multi-analyte profiling and intracellular signaling evaluated by array. IL-1β induced a cytokine-mediated inflammatory LPS-like signalome, with upregulation of pro-inflammatory cytokines such as interferon gamma (IFNγ,15.2-fold,p = 0.001), chemokine (C-X-C motif) ligand 1 (CXCL1,8.4-fold,p = 0.005), and tumor necrosis factor alpha (TNFα,11.2-fold,p = 0.004). IL-4 induced strong intracellular signaling with upregulation of mitogen-activated protein kinase kinase (MEK1;1.9-fold,p = 0.0005) and downregulation of signal transducer and activator of transcription 4 (STAT4;0.77-fold,0.001). MMP-12 increased IL-4 secretion 20-fold and induced a robust apoptotic neutrophil signalome with upregulation of forkhead box O1 (FOXO1;1.4-fold,p < 0.0001) and downregulation of WNT signaling with MMP-12 cleavage of the adherens junction components β-catenin, cahderin-3, and catenin-α2. In conclusion, neutrophils shifted phenotype by stimuli, with MMP-12 inducing a unique apoptotic signalome with higher resemblance to the anti-inflammatory signalome. SIGNIFICANCE: This study revealed that neutrophils demonstrate unique polarization signaling responses to specific stimuli, with the matrix metalloproteinase (MMP)-12 signalome showing similarity to the IL-4 signalome. MMP-12 polarized neutrophils towards a strong apoptotic signature by upregulating FOXO1 and downregulating WNT signaling. Our results highlight that neutrophils display more plasticity than previously appreciated.

Resveratrol Alleviating the Ovarian Function Under Oxidative Stress by Alternating Microbiota Related Tryptophan-Kynurenine Pathway

Oxidative stress (OS) is a key factor regulating the systemic pathophysiological effects and one of the fundamental mechanisms associated with aging and fertility deterioration. Previous studies revealed that resveratrol (RV) exhibits a preventive effect against oxidative stress in the ovary. However, it remains unknown whether gut microbiota respond to resveratrol during an OS challenge. In Exp. 1, layers received intraperitoneal injection of tert-butyl hydroperoxide (tBHP) (0 or 800 μmol/kg BW) or received resveratrol diets (0 or 600 mg/kg) for 28 days. In Exp. 2, the role of intestinal microbiota on the effects of resveratrol on tBHP-induced oxidative stress was assessed through fecal microbiota transplantation (FMT). The OS challenge reduced the egg-laying rate and exhibited lower pre-hierarchical follicles and higher atretic follicles. Oral RV supplementation ameliorated the egg-laying rate reduction and gut microbiota dysbiosis. RV also reversed the tryptphan-kynurenine pathway, upregulated nuclear factor E2-related factor 2 (Nrf2) and silent information regulator 1(SIRT1) levels, and decreased the expression of forkhead box O1 (FoxO1) and P53. These findings indicated that the intestinal microbiota-related tryptophan-kynurenine pathway is involved in the resveratrol-induced amelioration of ovary oxidative stress induced by tBHP in the layer model, while SIRT1-P53/FoxO1 and Nrf2-ARE signaling pathway were involved in this process.

The effects of light colour on female rabbit reproductive performance and the expression of key genes in follicular development

The purpose of this study was to analyse the effects of light colour on rabbit reproductive performance and the expression of key follicular development genes. Rabbits (n = 1,068, 5 months old, 3.6–4.4 kg live body weight) were divided randomly into four groups, housed individually in wire mesh cages and exposed to red, green, blue, and white light-emitting diode (LED) light (control). The lighting schedule was 16 L : 8 D-15 d / 150 lx / 6:00 am–22:00 pm (3 d preartificial insemination to 12 d postartificial insemination). Red light and white light affected the conception rate and kindling rate and increased the total litter size at birth (p < 0.05). The effects of red light on litter size at weaning, litter weight at weaning, and individual weight at weaning increased compared with the green and blue groups. The effects of red light on live litter size at birth were increased compared with those in the blue group (p < 0.05). Compared to white light, green and blue light reduced the number of secondary follicles (p < 0.05). Compared to red light, green and blue light reduced the number of tertiary follicles (p < 0.05). Compared with white light, red LED light resulted in greater ovarian follicle stimulating hormone receptor and luteinizing hormone receptor mRNA expression (p < 0.05). Compared with green and blue LED light, red LED light resulted in greater B-cell lymphom-2 mRNA expression (p < 0.05). Compared with green LED light, red LED light inhibited FOXO1 mRNA expression in rabbit ovaries (p < 0.05). Red light can affect the reproductive performance of female rabbits and the expression of key genes for follicular development.

Reactive oxygen species-induced SIAH1 promotes granulosa cells' senescence in premature ovarian failure

Reactive oxygen species (ROS) exposure triggers granulosa cells' (GCs) senescence, which is an important causal factor for premature ovarian failure (POF). However, underlying mechanism in this process remains unknown. In our study, we observed increased ROS levels in POF ovarian tissues, POF patient follicular GCs and cyclophosphamide (CTX) pretreated GCs. Correspondingly, increased SIAH1, reduced TRF2 and GC senescence were also found in these cases. Silencing of SIAH1 rescued ROS‐induced TRF2 reduction and cell senescence in GCs. Moreover, SIAH1 co‐localized with TRF2 in the cytoplasm, facilitating its ubiquitination degradation, further leading to telomere abnormalities in GCs. In conclusion, our findings indicate that ROS induces telomere abnormalities by augmenting SIAH1‐mediated TRF2 degradation, leading to cell senescence in GCs in POF processing.

Protective Effect of Grape Seed Proanthocyanidins on Oxidative Damage of Chicken Follicular Granulosa Cells by Inhibiting FoxO1-Mediated Autophagy

A significant decrease in poultry egg production occurs due to ovarian aging and autophagy is one of the important factors of ovarian aging that is induced predominantly by oxidative stress. Increasing evidence showed potential roles of plant-derived grape seed proanthocyanidin (GSPs) in protecting ovarian granulosa cells (GCs) from oxidative damage, although the underlying mechanism is still unclear. Here we investigated the possible functions of autophagy involved in the preventive effect of GSPs on oxidative stress in the GCs of ovarian hierarchical follicles of laying chickens. The results showed that increased autophagy was observed in the aging hens (580-day-old, D580) compared with the peak-lay hens (D280). Treatment of GSPs significantly restored the elevated autophagy and decreased viability of cultured D280 chicken GCs that were elicited by hydrogen peroxide. GSPs also suppressed the increased autophagy in the natural aging hens. Similar to the effect of GSPs on GC viability, inhibition of autophagy also showed a protective effect on the decreased viability of GCs under oxidative damage. However, GSPs were not able to provide further protection in GCs that were pretreated with 3-methyladenine (an autophagy inhibitor). In addition to its promoting action on antioxidant capacity, treatment with GSPs increased survival of GCs from autophagy that was caused by oxidative stress through the FoxO1-related pathway. Inhibition of FoxO1 or activation of PI3K-Akt pathway by GSPs increased the confrontation of GCs to oxidative damage and decreased autophagy in GCs. In addition, activation of the SIRT1 signal inhibited the GCs autophagy that was caused by oxidative stress via GSPs-induced deacetylation of FoxO1. These results revealed a new mechanism of GSPs against oxidative stress of GCs via inhibiting FoxO1, which was probably a possible target for alleviating ovarian aging in laying poultry.

Dietary resveratrol improved production performance, egg quality, and intestinal health of laying hens under oxidative stressRESVERATROL IN LAYING HENS

Resveratrol (RV) is associated with protection against oxidative stress to improve health, however the effect of RV in layers under oxidative stress (OS) is limited. The objective of this experiment was to investigate the negative effect of OS and protective effects of RV against OS in laying hens. 40 Lohmann layers (25-wk-old; BW = 1.44±0.10 kg) were allocated to four treatments in a 2 × 2 factorial arrangement with either RV (0 or 600 mg/kg) or intraperitoneal injection of tert-butyl hydroperoxide (tBHP) (0 or 800 μmol/kg BW) for 31 days. The results shown that the hens challenged with tBHP presented lower egg-laying rate, feed intake, feed efficiency and higher defective egg rate (P_(tBHP)<0.05). The RV were also observed to attenuated egg laying rate and feed intake reduction together with decreased broken egg rate under t-BHP challenge (P_{(Interaction)}≤0.01). The tBHP challenged layer demonstrated lower intestinal morphology (villus height in duodenum and jejunum), lower antioxidant enzymes activities [total superoxidase (SOD), glutathione peroxidase (GSH-Px), total antioxidant capacity (T-AOC)], and glutathione (GSH) levels and higher malondialdehyde (MDA) level] (P_(tBHP)<0.05). Dietary RV increased jejunal SOD, GSH-Px and T-AOC activities, and reduced MDA concentration (P_(RV) ≤0.05). Layers under tBHP challenge up-regulated mRNA expression of pro-inflammatory cytokine [interleukin-1β (IL-1β), interleukin-6 (IL-6), and tumor necrosis factor-α (TNF-α)] and nuclear factor NF-κB (P_(tBHP)<0.05) in jejunum. Dietary RV supplementation down-regulated mRNA gene expression of IL-1β, IL-6, TNF-α and NF-κB (P_(RV) ≤0.05). Dietary RV up-regulated mRNA expression of jejunal barrier-related proteins (claudin-1, claudin-2, mucin-1, and occludin) and ovarian reproductive hormone receptor [steroidogenic acute regulatory protein (StAR), androgen receptor (AR), estrogen receptor 1 (ESR1), and activin a receptor type 1 (ACVR1)] (P_(RV) ≤0.05). Overall, the results indicate that tBHP induced oxidative stress to result in reducing production performance, intestinal health and induced ovarian inflammation; whereas dietary RV was able to maintain intestinal health and mitigate the negative impact of tBHP challenge on production performance and ovarian function.

Concentrated ambient fine particles exposure affects ovarian follicle development in mice

BACKGROUND

Ambient fine particles (PM_2.5) are known to cause various reproductive and developmental diseases. However, the potential mechanisms of PM_2.5 exposure induced female reproductive damage remain unclear.

METHODS

Four weeks old female C57BL/6 J mice were exposed to filtered air (FA, n = 10) or concentrated ambient PM_2.5 (CAP, n = 10) using a versatile aerosol concentration enrichment system. After 9 weeks of the exposure, mice were sacrificed under sevoflurane anesthesia and tissue samples were collected. Immunohistochemical analysis, enzyme-linked immunosorbent assay, quantitative polymerase chain reaction, and RNA-sequencing were performed to analyze the effects of PM_2.5 exposure on follicle development and elucidate its potential mechanisms.

RESULTS

Chronic PM_2.5 exposure resulted in follicular dysplasia. Compared to the FA-exposed group, follicular atresia in the CAP-exposed mice were significantly increased. Further studies confirmed that CAP induced apoptosis in granulosa cells, accompanied by a distortion of hormone homeostasis. In addition, RNA-sequencing data demonstrated that CAP exposure induced the alteration of ovarian gene expressions and was associated with inflammatory response.

CONCLUSIONS

Chronic exposure to CAP can induce follicular atresia, which was associated with hormone modulation and inflammation.

Impairment of Decidualization of Endometrial Stromal Cells by hsa-miR-375 Through NOX4 Targeting

Decidualization of the endometrial stromal cells (ESCs) is essential for successful embryo implantation. It involves the transformation of fibroblastic cells into epithelial-like cells that secrete cytokines, growth factors, and proteins necessary for implantation. Previous studies have revealed altered expression of miR-375 in the endometrium of patients with recurrent implantation failure and the ectopic stromal cells of patients with endometriosis. However, the exact molecular mechanisms, particularly the role of microRNAs (miRNAs) in the regulation of decidualization, remain elusive. In this study, we investigated whether decidualization is affected by miR-375 and its potential target(s). The findings demonstrated the downregulation of the expression of miR-375 in the secretory phase compared to its expression in the proliferative phase of the endometrium in normal donors. In contrast, it was upregulated in the secretory phase of the endometrium in infertility patients. Furthermore, during decidualization of ESCs in vitro, overexpression of miR-375 significantly reduced the transcript-level expression of forkhead box protein O1 (FOXO1), prolactin (PRL), and insulin-like growth factor binding protein-1 (IGFBP1), the well-known decidual cell markers. Overexpression of miR-375 also resulted in reduced decidualization-derived intracellular and mitochondrial reactive oxygen species (ROS) levels. Using the luciferase assay, we confirmed that NADPH oxidase 4 (NOX4) is a direct target of miR-375. Collectively, the study showed that the miR-375-mediated NOX4 downregulation reduced ROS production and attenuated the decidualization of ESCs. It provides evidence that miR-375 is a negative regulator of decidualization and could serve as a potential target for combating infertility.

Circadian clock regulates granulosa cell autophagy through NR1D1-mediated inhibition of ATG5

Autophagy of granulosa cells (GCs) is involved in follicular atresia, which occurs repeatedly during the ovarian development cycle. Several circadian clock genes are rhythmically expressed in both rodent ovarian tissues and GCs. Nuclear receptor subfamily 1 group D member 1 (NR1D1), an important component of the circadian clock system, is involved in the autophagy process through the regulation of autophagy-related genes. However, there are no reports illustrating the role of the circadian clock system in mouse GC autophagy. In the present study, we found that core circadian clock genes (Bmal1, Per2, Nr1d1, and Dbp) and an autophagy-related gene (Atg5) exhibited rhythmic expression patterns across 24 h in mouse ovaries and primary GCs. Treatment with SR9009, an agonist of NR1D1, significantly reduced the expression of Bmal1, Per2, and Dbp in mouse GCs. ATG5 expression was significantly attenuated by SR9009 treatment in mouse GCs. Conversely, Nr1d1 knockdown increased ATG5 expression in mouse GCs. Decreased NR1D1 expression at both the mRNA and protein levels was detected in the ovaries of Bmal1^-/- mice, along with elevated expression of ATG5. Dual-luciferase reporter assay and electrophoretic mobility shift assay showed that NR1D1 inhibited Atg5 transcription by binding to two putative retinoic acid-related orphan receptor response elements within the promoter. In addition, rapamycin-induced autophagy and ATG5 expression were partially reversed by SR9009 treatment in mouse GCs. Taken together, our current data demonstrated that the circadian clock regulates GC autophagy through NR1D1-mediated inhibition of ATG5 expression, and thus, plays a role in maintaining autophagy homeostasis in GCs.

Protective effect of astaxanthin on experimental ovarian damage in rats

This study aimed to investigate the protective effect of astaxanthin (AS) on 3-nitropropionic acid (3-NPA) induced experimental ovarian damage in rats. Thirty two female Wistar rats were divided into four equal groups of eight each: control group (C); phosphate-buffered saline, AS group; AS (80 mg/kg) for 14 days, 3-NPA group; 3-NPA (6.25 mg/kg) twice a day for 7 days, 3-NPA + AS group; administered AS (80 mg/kg) for 14 days and 3-NPA (6.25 mg/kg) for 7 days. All injections were administered intraperitoneally. Rats were fed ad libitum with standard rat chow and tap water. Plasma and ovarian tissue total antioxidant capacity (TAC), total oxidant capacity (TOC) and oxidative stress index (OSI) levels, whole blood reduced glutathione (GSH), plasma paraoxonase 1 (PON1) activity, lipid profile, malondialdehyde (MDA), nitric oxide (NO), total sialic acid (TSA) and total thiol (TT) concentrations were analysed spectrophotometrically. Also, ovarian tissue histopathology was performed. We observed 3-NPA-induced histopathological ovarian damage significantly decreased the TAC (p < 0.001), GSH (p < 0.001), high-density lipoprotein (p < 0.01) levels and PON1 activity (p < 0.01), and significantly increased TOC, OSI (p < 0.001), MDA, NO, TSA, cholesterol, low-density lipoprotein (p < 0.01) and triglyceride (p < 0.05) levels. In conclusion, cotreatment with AS restored the negative effect of 3-NPA on all biochemical parameters cited above and improved the histopathological ovarian damage. Ovarian toxicity induced by 3-NPA might be due to oxidative damage. The improvement of AS seems to be related to its antioxidant properties.

The role of FoxO1 and its modulation with small molecules in the development of diabetes mellitus: A review

Diabetes mellitus type 2 (T2D) is one of the metabolic disorders suffered by a global human being. Certain factors, such as lifestyle and heredity, can increase a person's tendency for T2D. Various genes and proteins play a role in the development of insulin resistance and ultimately diabetes in which one central protein that is discussed in this review is FoxO1. In this review, we regard FoxO1 activation as detrimental, promote high plasma glucose level, and induce insulin resistance. Indeed, many contrasting studies arise since FoxO1 is an important protein to alleviate oxidative stress and promote cell survival, for example, also by preventing hyperglycemic-induced cell death. Inter-relation to PPARG, another important protein in metabolism, is also discussed. Ultimately, we discussed contrasting approaches of targeting FoxO1 to combat diabetes mellitus by small molecules.

USP25 Regulates the Proliferation and Apoptosis of Ovarian Granulosa Cells in Polycystic Ovary Syndrome by Modulating the PI3K/AKT Pathway via Deubiquitinating PTEN

Background: Polycystic ovarian syndrome (PCOS) is an endocrine-related disease related to abnormal folliculogenesis and is a leading cause of infertility worldwide. Inhibition of granulosa cells (GCs) proliferation and increased GCs apoptosis have been identified as the major factors in aberrant follicle maturation. Methods: USP25 and PTEN expression in GCs from women with and without PCOS was analyzed using Western blotting. A PCOS-like mouse model was constructed using USP25 knockout and wild-type mice to explore the role of USP25 in PCOS. The human granular cell line KGN was cultured for proliferation and apoptosis assays, and the effect of USP25 on PTEN was investigated after transfection with shRNA-USP25 lentivirus. Results: USP25 expression was found to be elevated in patients and mice with PCOS. With mouse model, we observed a reduction in PCOS symptoms in mice after USP25 deletion. Increased proliferation, reduced apoptosis, activation of the phosphoinositide-3-kinase (PI3K)/protein kinase B (AKT) signaling pathway and decreased PTEN expression were found in KGN cells after USP25 knockdown. Finally, we verified that USP25 could deubiquitinate PTEN in KGN cells. Conclusions: In this study, we investigated that USP25 can regulate the PI3K/AKT signaling pathway by deubiquitinating PTEN, thus affecting the proliferation and apoptosis of GCs and contributing to the pathogenesis of PCOS.

The Effect of Oxidative Stress on the Chicken Ovary: Involvement of Microbiota and Melatonin Interventions

The poultry ovary is used as a classic model to study ovarian biology and ovarian cancer. Stress factors induced oxidative stress to cause follicle atresia, which may be a fundamental reason for the reduction in fertility in older laying hens or in aging women. In the present study, we set out to characterize the relationships between oxidative stress and ovarian function. Layers (62 weeks of age; BW = 1.42 ± 0.12 kg) were injected with tert-butyl hydroperoxide (tBHP) at 0 (CON) and 800 μmol/kg BW (oxidative stress group, OS) for 24 days and the role of melatonin (Mel) on tBHP-induced ovary oxidative stress was assessed through ovary culture in vitro. The OS (800 μmol/kg BW tert-butyl hydroperoxide) treatment decreased the reproduction performance and ovarian follicle numbers. OS decreased the expression of SIRT1 and increased the P53 and FoxO1 expression of the ovary. A decreased Firmicutes to Bacteroidetes ratio, enriched Marinifilaceae (family), Odoribacter (genus) and Bacteroides_plebeius (species) were observed in the cecum of the OS group. Using Mel in vitro enhanced the follicle numbers and decreased the ovary cell apoptosis induced by tBHP. In addition, it increased the expression of SIRT1 and decreased the P53 and FoxO1 expression. These findings indicated that oxidative stress could decrease the laying performance, ovarian function and influence gut microbiota and body metabolites in the layer model, while the melatonin exerts an amelioration the ovary oxidative stress through SIRT1-P53/FoxO1 pathway.

Periplaneta americana peptide decreases apoptosis of pig-ovary granulosa cells induced by H2 O2 through FoxO1

Oxidative stress can induce apoptosis of granulosa cells and lead to follicular atresia, thereby reducing the number of pigs giving birth. The aim of this study was to investigate the protective effect of Periplaneta americana peptide (PAP) on the apoptosis of the granulosa cells of pig ovaries (PGCs) induced by hydrogen peroxide (H₂ O₂ ) via FoxO1. PGCs were treated with H₂ O₂ to establish a cell apoptosis model. Cell viability was measured using the cell counting kit-8 (CCK-8) assay, and cell apoptosis was detected using flow cytometry. The malondialdehyde (MDA) level and nitric oxide (NO) content were detected to reflect the oxidative stress. Western blotting, qRT-PCR and overexpression were undertaken to determine the expression of FoxO1 and caspase-3, and immunofluorescence was used to detect FoxO1 in the nucleus and cytoplasm. PGCs were treated with 100 μM H₂ O₂ for 6 hr, which resulted in oxidative damage and apoptosis and an apoptosis rate for PGCs of 32.95%. Next, PGCs were treated with 400 μg/ml PAP for 24 hr to repair the apoptosis induced by H₂ O₂ . PAP improved cell viability in H₂ O₂ -stimulated PGCs, the increased MDA level and NO content caused by H₂ O₂ stimulation were reversed and the apoptotic rate of PGCs was reduced. The qRT-PCR and Western blotting results indicated that PAP decreased the H₂ O₂ -induced apoptosis and the expression of FoxO1 and caspase-3 in PGCs. The effect of PAP was the same following FoxO1 overexpression. FoxO1 was expressed in the nucleus when stimulated by H₂ O₂ or overexpression; however, it migrated to the cytoplasm following PAP treatment. PAP decreased the apoptosis of PGCs induced by H₂ O₂ by regulating FoxO1 expression and nuclear translocation.

FOXO1 mediates hypoxia-induced G0/G1 arrest in ovarian somatic granulosa cells by activating the TP53INP1-p53-CDKN1A pathway

The development of ovarian follicles constitutes the foundation of female reproduction. The proliferation of granulosa cells (GCs) is a basic process required to ensure normal follicular development. However, the mechanisms involved in controlling GC cell cycle are not fully understood. Here, by performing gene expression profiling in the domestic pig (Sus scrofa), we showed that cell cycle arrest at G0/G1 phase is highly correlated with pathways associated with hypoxic stress and FOXO signalling. Specifically, the elevated proportion of GCs at the arrested G0/G1 phase was accompanied by increased nuclear translocation of FOXO1 under conditions of hypoxia both in vivo and in vitro. Furthermore, phosphorylation of 14-3-3 by the JNK kinase is required for hypoxia-mediated FOXO1 activation and the resultant G0/G1 arrest. Notably, a FOXO1 mutant without DNA-binding activity failed to induce G0/G1 arrest of GCs during hypoxia. Importantly, we identified a new target gene of FOXO1, namely TP53INP1, which contributes to suppression of the G1-S cell cycle transition in response to hypoxia. Furthermore, we demonstrated that the inhibitory effect of the FOXO1-TP53INP1 axis on the GC cell cycle is mediated through a p53-CDKN1A-dependent mechanism. These findings could provide avenues for the clinical treatment of human infertility caused by impaired follicular development.