Ovarian Stress Research Articles

TIGAR relieves PCOS by inhibiting granulosa cell apoptosis and oxidative stress through activating Nrf2

This study aimed to elucidate the role of TP53-induced glycolysis and apoptosis regulator (TIGAR) in polycystic ovary syndrome (PCOS). A rat model PCOS was constructed by subcutaneous injection with dehydroepiandrosterone (DHEA). Follicular atresia and reduced granular cells (GCs) in ovaries suggested successful modeling. The low expression of TIGAR was observed in ovarian tissue of PCOS rat. To explore the role of TIGAR in PCOS, lentivirus carrying the TIGAR were used to up-regulate TIGAR expression. TIGAR overexpression reduced the DHEA-induced increase of ovarian weight, the levels of estradiol (E2), and the ratio of luteinizing hormone/follicle-stimulating hormone (LH/FSH) in the serum, as well as improved the morphology of the follicle, especially increased the thickness of the GC layer, which attributed to the inhibition of apoptosis by TIGAR. In addition, high expression of TIGAR inhibited oxidative stress in ovaries of PCOS rat, as evidenced by decreased level of malondialdehyde (MDA), and reactive oxygen species (ROS), and enhanced activity of glutathione peroxidase (GPX) and superoxide dismutase (SOD). Mechanically, Nrf2/OH-1 signal pathway was activated by TIGAR. The effect of TIGAR on PCOS were verified in the primary rat GCs treated with dihydrotestosterone, but also the rescue experiment was performed. Downregulation of Nrf2 reversed the effects of TIGAR, indicating that TIGAR suppressed oxidative stress and GC apoptosis by activating Nrf2/OH-1 pathway in PCOS. Finally, non-targeted metabolomics revealed that TIGAR might affect the energy metabolic pathway, thereby altering the metabolic profile of primary rat GCs. This study provided new insights into the prevention and treatment of PCOS.

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 sequencingand 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.

Oxidative activity of corpus luteum and ovarian parenchyma in Bos taurus indicus heifers.

The aim of this study was to evaluate the oxidative stress in ovaries and corpus luteum (CL) of Bos taurus indicus females and the oxidant effect of CL in ovarian tissues in regions near, intermediate, or distant from it. Ovaries (n=12) of Nelore heifers (n=6) were collected from a slaughterhouse and fragmented. Experiment 1, each ovary was obtained from three fragments, resulting in 18 fragments of ovaries with CL (OV+CL) and another 18 fragments of ovaries without CL (OV-CL). Three fragments were generated from CL, totaling 18 CL fragments. In experiment 2, the ovarian fragments were removed from specific regions near, intermediate, or distant from the CL. All the fragments were placed in Eppendorf-type microtubes (1 mL), kept in a thermal container at 4 ºC, and then stored in a -80 ºC freezer for analysis of oxidative stress (TBARS and NBT) and antioxidant potential (FRAP and ABTS). In the antioxidant activity analysis, luteal tissues showed more antioxidant activity than ovarian tissue (FRAP = P < 0.0001; ABTS = P < 0.02). In the oxidative stress analysis, CL had lower levels of reactive oxygen species (ROS; TBARS = P < 0.03; NBT = P < 0.0001) than ovarian tissues. There was no difference in antioxidant activity and oxidative stress between the fragments obtained from different regions (OV+CL versus OV-CL; P > 0.05). The presence of CL in the ovaries of Bos taurus indicus females did not influence the oxidative stress or antioxidant potential of the gonad. Thus, the removal of ovarian fragments with or without the presence of CL indicates that biotechnologies such as in vitro follicle cultivation is possible.

Oxidative stress in the ovaries of mice chronically exposed to a low lead concentration: A generational approach

Lead (Pb) is a heavy metal that alters the oxidation-reduction balance, affecting reproductive health and transfer during pregnancy and lactation. However, the multigenerational impact of exposure to low concentrations of Pb on mammalian ovaries has not been assessed. This study evaluated general parameters, histology, redox state (RS), protein carbonylation (PC), lipid peroxidation (LP), and hormone concentrations in the ovaries of mice (CD1® ICR) of three successive generations with both unigenerational (E1) and multigenerational (E2) exposure to 0.2 ppm lead acetate through the drinking water and a control group. Body weight, food consumption, the number of born pups, and their weight after weaning were not significantly affected by Pb exposure in E1 and E2. However, the ovaries of three successive generations of the E1 group, in which only the F0 was exposed, showed alterations in the ovarian histoarchitecture, increase in follicular atresia, decrease in the number of available follicles, and a significant RS and PC elevation that were surprisingly similar to those observed in the E2 group. LP increased in the second generation of E1 and E2, while hormone concentration was not altered. This is the first demonstration that exposure to low concentration of Pb induces multigenerational histological alterations and oxidative stress in mouse ovaries, that the termination of this exposure does not ensure the safety of later generations and that the lack of modifications in general parameters may facilitate the silent development of pathologies that affect ovarian health.

Gestational Benzo[a]pyrene Exposure Destroys F1 Ovarian Germ Cells Through Mitochondrial Apoptosis Pathway and Diminishes Surviving Oocyte Quality.

Polycyclic aromatic hydrocarbons, including benzo[a]pyrene (BaP), are products of incomplete combustion. In female mouse embryos primordial germ cells proliferate before and after arriving at the gonadal ridge around embryonic (E) 10 and begin entering meiosis at E13.5. Now oocytes, they arrest in the first meiotic prophase beginning at E17.5. We previously reported dose-dependent depletion of ovarian follicles in female mice exposed to 2 or 10 mg/kg-day BaP E6.5-15.5. We hypothesized that embryonic ovaries are more sensitive to gestational BaP exposure during the mitotic developmental window, and that this exposure results in persistent oxidative stress in ovaries and oocytes of exposed F1 female offspring. We orally dosed timed-pregnant female mice with 0 or 2 mg/kg-day BaP in oil from E6.5-11.5 (mitotic window) or E12.5-17.5 (meiotic window). Cultured E13.5 ovaries were utilized to investigate the mechanism of BaP-induced germ cell death. We observed statistically significant follicle depletion and increased ovarian lipid peroxidation in F1 pubertal ovaries following BaP exposure during either prenatal window. Culture of E13.5 ovaries with BaP induced germ cell DNA damage and release of cytochrome c from the mitochondria in oocytes, confirming that BaP exposure induced apoptosis via the mitochondrial pathway. Mitochondrial membrane potential, oocyte lipid droplet (LD) volume, and mitochondrial-LD colocalization were decreased and mitochondrial superoxide levels were increased in the MII oocytes of F1 females exposed gestationally to BaP. Results demonstrate similar sensitivity to germ cell depletion and persistent oxidative stress in F1 ovaries and oocytes following gestational BaP exposure during mitotic or meiotic windows.

Ovary Abortion Induced by Combined Waterlogging and Shading Stress at the Flowering Stage Involves Amino Acids and Flavonoid Metabolism in Maize.

Maize (Zea mays L.) crops on the North China Plain are often subject to continuous overcast rain at the flowering stage. This causes waterlogging and shading stresses simultaneously and leads to huge yield losses, but the causes of these yield losses remain largely unknown. To explore the factors contributing to yield loss caused by combined waterlogging and shading stress at the flowering stage, we performed phenotypic, physiological, and quasi-targeted metabolomics analyses of maize plants subjected to waterlogging, shading, and combined waterlogging and shading (WS) treatments. Analyses of phenotypic and physiological indexes showed that, compared with waterlogging or shading alone, WS resulted in lower source strength, more severe inhibition of ovary and silk growth at the ear tip, a reduced number of emerged silks, and a higher rate of ovary abortion. Changes in carbon content and enzyme activity could not explain the ovary abortion in our study. Metabolomic analyses showed that the events occurred in ovaries and silks were closely related to abortion, WS forced the ovary to allocate more resources to the synthesis of amino acids involved in the stress response, inhibited the energy metabolism, glutathione metabolism and methionine salvage pathway, and overaccumulation of H2O2. In silks, WS led to lower accumulation levels of specific flavonoid metabolites with antioxidant capacity, and to over accumulation of H2O2. Thus, compared with each single stress, WS more seriously disrupted the normal metabolic process, and resulted more serious oxidative stress in ovaries and silks. Amino acids involved in the stress response in ovaries and specific flavonoid metabolites with antioxidant capacity in silks play important roles during ovary abortion. These results identify novel traits for selection in breeding programs and targets for genome editing to increase maize yield under WS stress.

The relationship of 4-vinylcyclohexene diepoxide toxicity with cell death, oxidative stress, and gap junctions in female rat ovaries.

PurposeIt was aimed to investigate the damage caused by VCD toxicity in the ovary, which women working in the industrial field are frequently exposed to, and to show the relationship between gap junction protein, oxidative stress, and apoptosis, which is thought to be effective in the emergence of this damage.MethodsRats were divided into three groups as control, sham, and VCD. Histological stainings were performed for histopathological evaluations in ovary. Serum AMH level was measured with the ELISA. Then, iNOS, caspase 3, connexin 43 protein, and mRNA expression levels were analyzed by immunohistochemistry and RT‐qPCR methods.ResultsAs a result of the analyses, different amounts of degenerations such as hemorrhage, vacuolization, and fibrosis were observed in the ovary. VCD group AMH level decreased compared to control. In VCD group, iNOS and caspase 3 expressions increased, while connexin 43 expression decreased.ConclusionsIt was shown that VCD caused damage to all ovarian tissue. Also, it was revealed for the first time that VCD triggered apoptosis by increasing oxidative stress in the ovary and suppressed connexin 43 which was also effective in the survival of granulosa cells. The devastating effect of exposure to occupational chemicals such as VCD on fertility was demonstrated in this study.

Oxidized Oils and Oxidized Proteins Induce Apoptosis in Granulosa Cells by Increasing Oxidative Stress in Ovaries of Laying Hens.

The storage and preparation of corn for animal feed inevitably lead to lipid and protein peroxidation. Granulosa cells play an important role in follicular development in the ovaries, and hen laying productivity is likely to be dependent on follicle health and number. We hypothesized that oxidized oil and protein induce apoptosis via oxidative stress in laying hen granulosa cells. A sample of 360 38-week-old Lohmann commercial laying hens was used in a 2 × 2 factorial design for 8 weeks. Dietary treatments included dietary oil (fresh corn oil (FO) or oxidized corn oil (OO)) and corn gluten meal (fresh corn gluten meal (FP) or oxidized corn gluten meal (OP)). Productivity, ovarian histology, granulosa cell apoptosis, and indicators of oxidative stress were evaluated in all groups. Both dietary OO and OP decreased egg production and the average daily feed intake (ADFI) of laying hens. Flow cytometry, TUNEL, and real-time PCR revealed that both dietary OO and OP induced granulosa cell apoptosis in prehierarchical and hierarchical follicles. Furthermore, dietary OO and OP caused oxidative stress in prehierarchical and hierarchical follicles, as indicated by the downregulation of antioxidant-related-gene expression. Moreover, forkhead box O1 (FoxO1), extracellular regulated protein kinase (ERK), and c-Jun NH2 kinase (JNK) are involved in potential apoptosis regulation pathways in the granulosa cells of laying hens fed OO and OP, as indicated by the upregulation of FoxO1 expression and downregulation of ERK/JNK expression. These results indicate that OO and OP induce granulosa cell apoptosis via oxidative stress, and the combined use of OO and OP aggravates the adverse effects of oxidative stress in laying hens.

Effect of imidacloprid on antioxidant status and histopathological changes in ovary and uterus of adult female wistar rats

Imidacloprid is a neonicotinoid insecticide and has been extensively used as a crop pest and in pet flea control programme. In the present study, the effects of imidacloprid on ovary and uteri tissue was analyzed in adult female Wistar rats at two dose levels (19 and 38 mg/kg/day) administered orally for 10, 20 and 30 days. Effects were compared with respective control animals administered daily with 2% gum acacia. Parameters undertaken were organ weight, levels of cytoplasmic and membrane proteins, oxidative stress parameters viz. activities of SOD, GPx and levels of GSH and MDA and histopathological changes. IMI (38 mg/kg, 30 days) reduced cytoplamic proteins in both ovaries and uteri whereas this dose reduced membrane protein in ovaries only. IMI (38 mg/kg, 20 and 30 days) decreased SOD enzyme in both ovaries and uteri and GSH-Px levels in ovaries only. The GSH-Px levels were also seen with decreased levels in uteri with IMI (38 mg/kg) for 30 days. IMI (38 mg/kg, 20 and 30 days) induces degenerative changes in ovaries of rats. Hence, it is concluded from the present studies that administration of higher doses (38 mg/kg/day) of IMI for 20 and 30 days generated oxidative stress in ovaries and uteri of female rats.

Intravenous human endothelial progenitor cell administration into aged mice enhances embryo development and oocyte quality by reducing inflammation, endoplasmic reticulum stress and apoptosis.

Stem cell therapy has been proposed to restore the function and structure of injured tissues. In the present study, we investigated the ability of human endothelial progenitor cells (hEPCs) to attenuate ovarian aging and dysfunction. Female ICR mice aged 4 and 6 months were injected with cultured hEPCs. Cultured hEPCs were injected intravenously twice with 5 × 104 cells with a 4 day interval. After pregnant mare serum gonadotropin and human chorionic gonadotropin stimulation, oocytes and ovaries of aged mice were collected, cumulus-free oocytes were activated by SrCl2 and gene expression levels related to inflammation, apoptosis, follicle development and endoplasmic reticulum (ER) stress in ovaries were compared. Administration of hEPCs attenuated the level of inflammatory cytokines and adverse apoptotic factor, as well as reducing ER stress in the ovaries. Increased cleavage and blastocyst formation rates and cell numbers in blastocysts from hEPCs-treated aged mice vs. same aged control mice demonstrated a protective function of hEPCs against reproductive aging. Based on these data, we suggest that treatment with hEPCs attenuates reproductive aging and dysfunction potentially via regulation of inflammation, apoptosis and ER stress.

Effects of Nonylphenol-Induced Oxidative Stress in Ovary of Cichlid Fish, &lt;i&gt;Etroplus maculatus&lt;/i&gt; (Bloch, 1795)

The present study was designed to evaluate the effects of nonylphenol in the pro-oxidant/ antioxidant system in ovary of the cichlid fish Etroplus maculatus. Fishes were exposed at two sublethal concentrations (one-fifth and one-tenth of LC50) of nonylphenol for 24, 72 and 96 h maintaining control groups. The oxidative stress indices as the activities of antioxidant enzymes, superoxide dismutase, catalase, glutathione reductase along with the levels of hydrogen peroxide generation and lipid peroxidation were monitored in concentration-and time-dependent manner. Activity of superoxide dismutase significantly (P&lt;0.05) increased at both concentrations in time-dependent manner. Meanwhile the activities of catalase and glutathione reductase significantly (P&lt;0.05) decreased after 72 and 96 h of nonylphenol treatment. The levels of hydrogen peroxide generation and lipid peroxidation increased in all treatment groups when compared to controls. The present results demonstrated that the induction of oxidative stress in ovary of fish by the generation of lipid peroxidation could be due to the exposure of environmental contaminant, nonylphenol. Therefore, the observed oxidative stress in ovary can be indicated as a mechanism of toxicity in the fish exposed to nonylphenol.

Effects of Nonylphenol-Induced Oxidative Stress in Ovary of Cichlid Fish, &lt;i&gt;Etroplus maculatus&lt;/i&gt; (Bloch, 1795)

The present study was designed to evaluate the effects of nonylphenol in the pro-oxidant/ antioxidant system in ovary of the cichlid fishEtroplus maculatus. Fishes were exposed at two sublethal concentrations (one-fifth and one-tenth of LC50) of nonylphenol for 24, 72 and 96 h maintaining control groups. The oxidative stress indices as the activities of antioxidant enzymes, superoxide dismutase, catalase, glutathione reductase along with the levels of hydrogen peroxide generation and lipid peroxidation were monitored in concentration-and time-dependent manner. Activity of superoxide dismutase significantly (P&lt;0.05) increased at both concentrations in time-dependent manner. Meanwhile the activities of catalase and glutathione reductase significantly (P&lt;0.05) decreased after 72 and 96 h of nonylphenol treatment. The levels of hydrogen peroxide generation and lipid peroxidation increased in all treatment groups when compared to controls. The present results demonstrated that the induction of oxidative stress in ovary of fish by the generation of lipid peroxidation could be due to the exposure of environmental contaminant, nonylphenol. Therefore, the observed oxidative stress in ovary can be indicated as a mechanism of toxicity in the fish exposed to nonylphenol.

Comparative study on the effect of N-acetyl-cysteine versus sulpiride on experimentally induced stress in ovary of albino rats

Comparative study on the effect of N-acetyl-cysteine versus sulpiride on experimentally induced stress in ovary of albino rats

Alteration in estrous cycle, lipid peroxidation and antioxidant status in female rat after exposure to lambda cyhalothrin and its attenuation by taurine

Lambda cyhalothrin, a broad spectrum pyrethroid, is being extensively used against a wide range of pests in agricultural practices. The present study was highlighted to investigate the effects of the lambda cyhalothrin on estrous cycle and oxidative stress in rat ovary, also to find out the protective role of taurine against lambda cyhalothrin induced ovarian toxicity. Mature 36 female Wistar rats were divided in six groups and they were received oral administration of lambda cyhalothrin at two dose levels (8.33 and 16.66 mg/kg body wt) for consecutive14 days. Taurine (50mg/kg body wt) was treated before lambda cyhalothrin administration in the combined taurine-lambda cyhalothrin treated groups. Lambda cyhalothrin caused significant alterations in estrous cycle with an increase in diestrous index compared to control rats. Lambda cyhalothrin treatment also produced oxidative stress in ovary by significant increase in malondialdehyde level, accompanied by a reduction in reduced glutathione and antioxidant enzymes (superoxide dismutase, catalase, glutathione-s-transferase, glutathione peroxidase, glutathione reductase). The present study revealed that the pretreatment of taurine was able to ameliorate lambda cyhalothrin induced ovarian oxidative stress.