Follicle-stimulating hormone and estradiol interact to stimulate glutathione synthesis in rat ovarian follicles and granulosa cells

Building a Human Ovarian Antioxidant ceRNA Network "OvAnOx": A Bioinformatic Perspective for Research on Redox-Related Ovarian Functions and Dysfunctions

The ovary is a major determinant of female reproductive health. Ovarian functions are mainly related to the primordial follicle pool, which is gradually lost with aging. Ovarian aging and reproductive dysfunctions share oxidative stress as a common underlying mechanism. ROS signaling is essential for normal ovarian processes, yet it can contribute to various ovarian disorders when disrupted. Therefore, balance in the redox system is crucial for proper ovarian functions. In the present study, by focusing on mRNAs and ncRNAs described in the ovary and taking into account only validated ncRNA interactions, we built an ovarian antioxidant ceRNA network, named OvAnOx ceRNA, composed of 5 mRNAs (SOD1, SOD2, CAT, PRDX3, GR), 10 miRNAs and 5 lncRNAs (XIST, FGD5-AS1, MALAT1, NEAT1, SNHG1). Our bioinformatic analysis indicated that the components of OvAnOx ceRNA not only contribute to antioxidant defense but are also involved in other ovarian functions. Indeed, antioxidant enzymes encoded by mRNAs of OvAnOx ceRNA operate within a regulatory network that impacts ovarian reserve, follicular dynamics, and oocyte maturation in normal and pathological conditions. The OvAnOx ceRNA network represents a promising tool to unravel the complex dialog between redox potential and ovarian signaling pathways involved in reproductive health, aging, and diseases.

Association of Follicular Fluid Antioxidants Activity with Aging and In Vitro Fertilization Outcome: A Cross-Sectional Study

BACKGROUND

This research was aimed at assessing the relationship between the follicular fluid (FF) antioxidants activity, aging and in vitro fertilization (IVF) outcome.

MATERIALS AND METHODS

The present cross-sectional study was carried out on 65 women undergoing IVF/intracytoplasmic sperm injection (IVF/ICSI) cycles due to unexplained infertility. Ovarian stimulation was performed using the long gonadotropin-releasing hormone (GnRH) agonist protocol. After ovum pickup, FF was collected and processed to measure the level of superoxide dismutase (SOD), catalase (CAT) activity, total antioxidant capacity (TAC) and glutathione (GSH). Day 3 after ICSI, fresh embryos were transferred and later, possible pregnancy was assessed. Patients participating in this study were divided into four groups on the basis of age and pregnancy outcome.

RESULTS

SOD activity was not significantly different between the groups (P=0.218). GSH in the group whose participants were aged ≤35 years and were pregnant was higher than that in other groups. CAT activity in groups with younger participants was higher compared to the other groups. The mean TAC was higher in groups with pregnant participants compared to the non-pregnant women. Correlation analysis showed that: GSH level had a significant negative correlation with age (P<0.001, R -0.55) and a significant positive correlation with pregnancy (P=0.015, R=0.30). CAT level also had a significant negative correlation with age (P<0.001, R=-0.42) and the level of TAC had a significant positive correlation with pregnancy (P<0.001, R=0.59).

CONCLUSION

According to our results, the levels of TAC, GSH and CAT in younger and pregnant women were higher compared with those undergoing ICSI cycles. Given the correlation of FF antioxidant activity with age and pregnancy, it is necessary to carry out more research on these compounds and the maintenance of pregnancy.

Effects of a single dose of long-acting FSH on testicular blood flow, testicular echotexture, and circulating testosterone, estradiol, and nitric oxide in rams during the non-breeding season

The present study investigated the effect of a single administration of long-acting follicle simulation hormone (FSH) on testicular blood perfusion as measured by pulsed-wave Doppler ultrasonography, testicular echotexture, and circulating testosterone (T), estradiol (E2), and nitric oxide (NO) in the plasma of rams in the non-breeding season. Twelve Ossimi rams were subjected to either a single administration of long-acting FSH subcutaneously (FSH group; n = 6) or the vehicle (control group; n = 6). Assessment of testicular hemodynamics at the level of the supratesticular artery was performed just before administration (0 h), and at 4, 24, 48, 72, 96, and 168 h after FSH or the vehicle administrations. Testicular volume (TV), and echotexture of testicular parenchyma including pixel intensity and heterogeneity were derived by the computer analysis software. Concentrations of T, E2, and NO were measured using commercial kits. Results revealed significant decreases (P ˂ 0.05) in the values of Doppler indices (resistive index: RI and pulsatility index: PI), especially at 48 h after administration of FSH (RI: 0.42 ± 0.02, PI: 0.56 ± 0.04) compared to their values in the control group (RI: 0.54 ± 0.03, PI: 0.77 ± 0.04). FSH administration induced significant decreases (P ˂ 0.05) in the pixel intensity of testicular parenchyma. Testicular volume and T concentrations were not significantly changed (P ˃ 0.05). Concentrations of E2 increased significantly (P ˂ 0.05) at 48 h and 72 h after FSH administration. (30.07 ± 5.23 pg/ml, 29.93 ± 1.44 pg/ml, respectively) compared to their values before FSH administration (14.63 ± 1.37 pg/ml). Concentrations of NO increased significantly (P ˂ 0.05) in the FSH group between 4 h to 48 h compared to the values in the control one. In conclusion, a single administration of long-acting FSH enhanced testicular blood perfusion as measured by pulsed Doppler ultrasonography in rams during the non-breeding season. Concurrently, significant increases in the concentrations of E2 and NO were found.

The role of sex-differentiated variations in stress hormones, antioxidants, and neuroimmune responses in relation to social interaction impairment in a rodent model of autism

Males are more likely to develop autism as a neurodevelopmental disorder than females, but the mechanisms underlying male susceptibility are not fully understood. In this paper, we used a well-characterized propionic acid (PPA) rodent model of autism to study sex differences in stress hormones, antioxidants' status, and the neuroimmune response that may contribute to the preponderance of autism in males. Sprague Dawley rats of both sexes were divided into a saline-treated group as controls and PPA-treated groups, receiving 250 mg/kg of PPA per day for three days. Animals' social behavior was examined using the three-chamber social test. Hormones (ACTH, corticosterone, melatonin, and oxytocin), oxidative stress biomarkers (glutathione, glutathione-S-transferase, and ascorbic acid), and cytokines (IL-6, IL-1α, IL-10, and IFNγ) were measured in the brain tissue of all the animals. The results showed a sex dimorphic social response to PPA treatment, where males were more susceptible to the PPA treatment and exhibited a significant reduction in social behavior with no effects observed in females. Also, sex differences were observed in the levels of hormones, antioxidants, and cytokines. Female rats showed significantly higher corticosterone and lower oxytocin, antioxidants, and cytokine levels than males. The PPA treatment later modulated these baseline differences. Our study indicates that the behavioral manifestation of autism in PPA-treated males and not females could be linked to neural biochemical differences between the sexes at baseline, which might play a protective role in females. Our results can contribute to early intervention strategies and treatments used to control autism, an increasingly prevalent disorder.

Redox imbalance in age-related ovarian dysfunction and perspectives for its prevention

The age at which women have their first child is increasing. This change represents a major health problem to society because advanced maternal age is related with a decay in fertility and an increase in the incidence of a variety of pregnancy complications and offspring health issues. The ovary stands as the main contributor for female reproductive ageing because of the progressive age-related decrease in follicle number and oocyte quality. Loss of redox homeostasis and establishment of an ovarian oxidative microenvironment are seen as major underlying causes for such downfall and impairment of ovarian function. Thus, the use of antioxidants to preserve fertility became an important field of research. In this review, new insights on mechanisms underlying the establishment of oxidative stress and its repercussions on ovarian ageing are addressed, along with the current state of knowledge on antioxidant supplementation and its contribution for healthy ageing and extension of ovarian lifespan.

Transcriptome analysis of sheep follicular development during prerecruitment, dominant, and mature stages after FSH superstimulation

Sheep is usually a monovular animal; superovulation technology is used to increase the number of offspring per individual and shorten generation intervals. To date, mature FSH superstimulatory treatments have been successfully used in sheep breeding, but much remains unknown about genes, pathways, and biological functions involved in follicular development. Therefore, in this study, we performed transcriptome profiling of small follicles (SFs; 2-2.5 mm), medium follicles (MFs; 3.5-4.5 mm), and large follicles (LFs; > 6 mm) in Mongolian ewes after FSH superstimulation. Furthermore, we identified differentially expressed genes and performed Kyoto Encyclopedia of Genes and Genomes pathway and Gene Ontology enrichment analyses in 3 separate pairwise comparisons. We found that ovarian steroidogenesis was significantly enriched in the SFs versus MFs analysis; the associated genes, cytochrome P450 family 19 (CYP19) and Hydroxy-delta-5-steroid dehydrogenase 3 beta- and steroid delta-isomerase 1 (HSD3B1), were significantly upregulated. Moreover, proline metabolism, glutathione metabolism, and PPAR signaling pathways were significantly enriched in the LFs versus SFs analysis; the associated genes, glutamate-cysteine ligase modifier subunit (GCLM) and cystathionine gamma-lyase (CTH), were significantly upregulated, whereas peroxisome proliferator-activated receptor gamma (PPARγ) was significantly downregulated. In summary, our study provides basic data and possible biological direction to further explore the molecular mechanism of sheep follicular development after FSH superstimulation.

Autophagy Contributes to Oxidative Stress-Induced Apoptosis in Porcine Granulosa Cells

Oxidative stress-induced granulosa cell (GC) death is a major cause of follicular atresia. As the major types of programmed cell death, autophagy and apoptosis have been observed in response to H₂O₂-mediated oxidative stress and have been demonstrated to be responsible for porcine GC death. To date, however, the cellular reactions linking autophagy to the apoptosis of porcine GC under oxidative stress are still poorly understood. Porcine GC were treated with H₂O₂, and autophagic flux was examined by western blotting. Cell viability and cell death assays were performed after cotreatment of porcine GC with autophagy activator (rapamycin) or inhibitor (3-methyladenine, 3-MA) together with H₂O₂. We revealed that short exposure (1-3 h) of porcine GC to H₂O₂ dramatically increased autophagic flux (1.8- to 2.5-fold over that in the control), whereas 6-12 h prolonged treatment decreased autophagy but elevated the caspase-3 activity and GC apoptotic rate. Furthermore, we showed that pretreatment with rapamycin exacerbated H₂O₂-mediated cytotoxicity and caspase-3 activation but that 3-MA or siRNAs specific for Beclin 1 and Atg7 genes ameliorated H₂O₂-mediated GC apoptosis. Together, our results indicate that autophagy plays a pivotal role in H₂O₂-mediated porcine GC apoptosis. Importantly, we show that the early induction of autophagic flux contributes to oxidative stress-induced apoptosis in porcine GC. The results also suggest that regulating the autophagy response in porcine GC under oxidative stress might be a new strategy for abnormal follicular atresia.

FSHR ablation induces depression-like behaviors

Alteration in reproductive hormones profile is associated with the increasing risk of menopausal depression in women. Serum follicle-stimulating hormone (FSH) level is changed during the menopause transition, while the effect of FSH on menopausal depression has remained undefined. In this study we investigated whether or how FSH affected menopausal depression in postmenopausal (ovariectomized) FSHR knockout mice (Fshr^−/−). We found that Fshr^−/− mice displayed aggravated depression-like behaviors, accompanied by severe oxidative stress in the whole brain, resulted from significantly reduced glutamate cysteine ligase modifier subunit (GCLm) in glutathione synthesis and glucose-6-phosphate dehydrogenase (G6PD) in NADP/NADPH transition. Importantly, administration of ROS scavenger N-acetyl cysteine (NAC, 150 mg · kg⁻¹ · d⁻¹, i.p. for 12 weeks) attenuated the depression-like behaviors of Fshr^−/− mice. Consistent with these in vivo experiment results, we found that pretreatment with FSH (50, 100 ng/mL) dose-dependently increased protein levels of GCLm and G6PD, and decreased the ROS production in N2a mouse neuroblastoma cells. These findings demonstrate that FSH signaling is involved in pathogenesis of menopausal depression, and likely to maintain the redox-optimized ROS balance in neurons.

Periovulatory insulin signaling is essential for ovulation, granulosa cell differentiation, and female fertility

Recent studies have demonstrated an essential role for insulin signaling in folliculogenesis as conditional ablation of Igf1r in primary follicles elicits defective follicle-stimulating hormone responsiveness blocking development at the preantral stage. Thus the potential role of insulin action in the periovulatory window and in the corpus luteum is unknown. To examine this, we generated conditional Insr,Igf1r, and double receptor knockout mice driven by Pgr-Cre. These models escape the preantral follicle block and in response to superovulatory gonadotropins exhibit normal distribution of ovarian follicles and corpora lutea. However, single ablation of Igf1r leads to subfertility and mice lacking both receptors are infertile. Double knockout mice have impaired oocyte development and ovulation. While some oocytes are released and fertilized, subsequent embryo development is retarded, and the embryos potentially fail to thrive due to lack of luteal support. In support of this, we found reduced expression of key enzymes in the steroid synthesis pathway and reduced serum progesterone. In addition to metabolic and steroidogenic pathways, RNA-sequencing analysis revealed transcription factor-3 as an important transcription factor downstream of insulin signaling. Collectively, these results highlight the importance of growth factors of the insulin family during two distinct windows of follicular development, ovulation, and luteinization.

Follicle-stimulating hormone inhibits cervical cancer via NF-κB pathway

Background

Follicle-stimulating hormone (FSH) has multiple biological functions. It is currently considered that FSH can inhibit cervical cancer, and our aim was to explore the underlying molecular mechanisms.

Materials and methods

An in vivo experiment using nude mice injected with HeLa cells was performed. Flow cytometry, western blotting, and real-time quantitative PCR analyses were done.

Results

Twenty one days after injection of HeLa cells, the subcutaneous tumor mass was significantly lower (P<0.01) in mice treated with 20 mIU/mL FSH, but did not disappear. In vitro observations indicated that FSH might inhibit cell proliferation and activate cell apoptosis to induce the reduction of HeLa cells. The mRNA and protein levels of Cyclin D1, Cyclin E1, and Caspase 3 changed accordingly as expected in vivo and in vitro. Moreover, FSH inactivated the nuclear factor-kappa B (NF-κB) pathway in subcutaneous tumors; the NF-κB(p65) activity in HeLa cells was significantly decreased using 20 mIU/mL FSH and was increased when FSH was administered along with lipopolysaccharide, accompanied by the same change of cell number. Further, FSH accelerated protein kinase A (PKA) activity, but inactivated glycogen synthase kinase 3 beta (GSK-3β) activity. Specific inhibition of PKA and/or GSK-3β provided in vitro evidence that directly supported the FSH-mediated inhibition of GSK-3β to inactivate NF-κB via the promotion of PKA activity.

Conclusion

Our data are the first description of the molecular regulatory mechanisms of FSH-mediated inhibition of the development of cervical cancer by decreasing the cell cycle and activating cell apoptosis via the PKA/GSK-3β/NF-κB pathway.

The Role of Antioxidant Enzymes in the Ovaries

Proper physiological function of the ovaries is very important for the entire female reproductive system and overall health. Reactive oxygen species (ROS) are generated as by-products during ovarian physiological metabolism, and antioxidants are indicated as factors that can maintain the balance between ROS production and clearance. A disturbance in this balance can induce pathological consequences in oocyte maturation, ovulation, fertilization, implantation, and embryo development, which can ultimately influence pregnancy outcomes. However, our understanding of the molecular and cellular mechanisms underlying these physiological and pathological processes is lacking. This article presents up-to-date findings regarding the effects of antioxidants on the ovaries. An abundance of evidence has confirmed the various significant roles of these antioxidants in the ovaries. Some animal models are discussed in this review to demonstrate the harmful consequences that result from mutation or depletion of antioxidant genes or genes related to antioxidant synthesis. Disruption of antioxidant systems may lead to pathological consequences in women. Antioxidant supplementation is indicated as a possible strategy for treating reproductive disease and infertility by controlling oxidative stress (OS). To confirm this, further investigations are required and more antioxidant therapy in humans has to been performed.

Neuroprotective actions of progesterone in an in vivo model of retinitis pigmentosa

Progesterone has been shown to have neuroprotective effects in experimental acute brain injury models, but little is known about the effects of steroid sex hormones in models of retinitis pigmentosa (RP). The aim of this study was to asses whether progesterone had a protective effect in one animal model of RP (the rd1 mice), and whether its action was due at least in part, to its ability to reduce free radical damage or to increase antioxidant defences. Rd1 and wild type (wt) mice received an oral administration of 100 mg/kg body/weight of progesterone on alternate days starting at postnatal day 7 (PN7) and were sacrificed at different postnatal days. Our results show that progesterone decreases cell death, as the number of TUNEL-positive cells were decreased in the ONL of the retina from treated rd1 mice. At PN15, treatment with progesterone increased values of ERG b-wave amplitude (p<0,5) when compared with untreated mice. Progesterone also decreased the observed gliosis in RP, though this effect was transient. Treatment with progesterone significantly reduced retinal glutamate concentrations at PN15 and PN17. To clarify the mechanism by which progesterone is able to decrease retinal glutamate concentration, we examined expression levels of glutamine synthase (GS). Our results showed a significant increase in GS in rd1 treated retinas at PN13. Treatment with progesterone, significantly increase not only GSH but also oxidized glutathione retinal concentrations, probably because progesterone is able to partially increase glutamate cysteine ligase c subunit (GCLC) at PN15 and PN17 (p<0,05). In summary, our results demonstrate that oral administration of progesterone appears to act on multiple levels to delay photoreceptor death in this model of RP.

Effects of gonadotropin on Fas and/or FasL expression and proliferation in rat ovary

Although gonadotropin is a dominant hormone involved in promoting ovarian follicle development in females, the mechanism by which gonadotropin regulates follicular development is still unknown. To systematically evaluate the effectiveness of the gonadotropin on apoptosis and proliferation of ovarian cells in vivo, rats were injected subcutaneously with eCG and/or anti-eCG antiserum. Equine chorionic gonadotropin treatment increased ovarian cell proliferation and expression of FSH receptors (FSHR) as revealed by increased immunostaining of proliferating cell nuclear antigen and FSHR in rat ovary. These effects did not occur in a follicular stage-dependent manner. Moreover, these actions were abolished by anti-eCG antiserum. However, granulosa cells exhibited more intense Fas- and FasL-positive immunostaining during all follicular stages in the anti-eCG antiserum group. We used Western blot analysis to confirm these results; Fas and FasL protein contents in rat ovaries were decreased by eCG. Meanwhile, proliferating cell nuclear antigen and FSHR expression were upregulated by eCG. However, all these eCG-induced regulations were reversed by anti-eCG antiserum treatment. Furthermore, there were no significant differences between the anti-eCG antiserum and control groups. These results indicate that eCG promotes follicular development via downregulation of death-inducer Fas/FasL expression and promotion of ovarian cell proliferation, which is partially mediated by FSHR.

Primate follicular development and oocyte maturation in vitro

The factors and processes involved in primate follicular development are complex and not fully understood. An encapsulated three-dimensional (3D) follicle culture system could be a valuable in vitro model to study the dynamics and regulation of folliculogenesis in intact individual follicles in primates. Besides the research relevance, in vitro follicle maturation (IFM) is emerging as a promising approach to offer options for fertility preservation in female patients with cancer. This review summarizes the current published data on in vitro follicular development from the preantral to small antral stage in nonhuman primates, including follicle survival and growth, endocrine (ovarian steroid hormone) and paracrine/autocrine (local factor) function, as well as oocyte maturation and fertilization. Future directions include major challenges and strategies to further improve follicular growth and differentiation with oocytes competent for in vitro fertilization and subsequent embryonic development, as well as opportunities to investigate primate folliculogenesis by utilizing this 3D culture system. The information may be valuable in identifying optimal conditions for human follicle culture, with the ultimate goal of translating the experimental results and products to patients, thereby facilitating diagnostic and therapeutic approaches for female fertility.

Roles of reactive oxygen species and antioxidants in ovarian toxicity

Proper functioning of the ovary is critical to maintain fertility and overall health, and ovarian function depends on the maintenance and normal development of ovarian follicles. This review presents evidence about the potential impact of oxidative stress on the well-being of primordial, growing and preovulatory follicles, as well as oocytes and early embryos, examining cell types and molecular targets. Limited data from genetically modified mouse models suggest that several antioxidant enzymes that protect cells from reactive oxygen species (ROS) may play important roles in follicular development and/or survival. Exposures to agents known to cause oxidative stress, such as gamma irradiation, chemotherapeutic drugs, or polycyclic aromatic hydrocarbons, induce rapid primordial follicle loss; however, the mechanistic role of ROS has received limited attention. In contrast, ROS may play an important role in the initiation of apoptosis in antral follicles. Depletion of glutathione leads to atresia of antral follicles in vivo and apoptosis of granulosa cells in cultured antral follicles. Chemicals, such as cyclophosphamide, dimethylbenzanthracene, and methoxychlor, increase proapoptotic signals, preceded by increased ROS and signs of oxidative stress, and cotreatment with antioxidants is protective. In oocytes, glutathione levels change rapidly during progression of meiosis and early embryonic development, and high oocyte glutathione at the time of fertilization is required for male pronucleus formation and for embryonic development to the blastocyst stage. Because current evidence suggests that oxidative stress can have significant negative impacts on female fertility and gamete health, dietary or pharmacological intervention may prove to be effective strategies to protect female fertility.

Arsenic induced progesterone production in a caspase-3-dependent manner and changed redox status in preovulatory granulosa cells

Arsenic contamination is a principal environmental health threat throughout the world. However, little is known about the effect of arsenic on steroidogenesis in granulosa cells (GCs). We found that the treatment of preovulatory GCs with arsenite stimulated progesterone production. A significant increase in serum level of progesterone was observed in female Sprague-Dawley rats following arsenite treatment at a dose of 10 mg/L/rat/day for 7 days. Further experiments demonstrated that arsenite treatment did not change the level of intracellular cyclic AMP (cAMP) or phosphorylated ERK1/2 in preovulatory GCs; however, progesterone production was significantly decreased when cAMP-dependent protein kinase (PKA) or ERK1/2 pathway was inhibited. This implied that the effect of arsenite on progesterone production may require cAMP/PKA and ERK1/2 signaling but not depend on them. Furthermore, we found that arsenite decreased intracellular reactive oxygen species (ROS) but increased the antioxidant glutathione (GSH) levels and mitochondrial membrane potential (ΔΨm) in parallel to the changes in progesterone production. Progesterone antagonist blocked the arsenic-stimulated increase of GSH levels. Arsenite treatment induced caspase-3 activation, although no apoptosis was observed. Inhibition of caspase-3 activity significantly decreased progesterone production stimulated by arsenite or follicle-stimulating hormone (FSH). GSH depletion with buthionine sulfoximine led to cell apoptosis in response to arsenite treatment. Collectively, this study demonstrated for the first time that arsenite stimulates progesterone production through cleaved/active caspase-3-dependent pathway, and the increase of GSH level promoted by progesterone production may protect GCs against apoptosis and maintain the steroidogenesis of GCs in response to arsenite treatment.

Changes in gene expression associated with reproductive maturation in wild female baboons

Changes in gene expression during development play an important role in shaping morphological and behavioral differences, including between humans and nonhuman primates. Although many of the most striking developmental changes occur during early development, reproductive maturation represents another critical window in primate life history. However, this process is difficult to study at the molecular level in natural primate populations. Here, we took advantage of ovarian samples made available through an unusual episode of human-wildlife conflict to identify genes that are important in this process. Specifically, we used RNA sequencing (RNA-Seq) to compare genome-wide gene expression patterns in the ovarian tissue of juvenile and adult female baboons from Amboseli National Park, Kenya. We combined this information with prior evidence of selection occurring on two primate lineages (human and chimpanzee). We found that in cases in which genes were both differentially expressed over the course of ovarian maturation and also linked to lineage-specific selection this selective signature was much more likely to occur in regulatory regions than in coding regions. These results suggest that adaptive change in the development of the primate ovary may be largely driven at the mechanistic level by selection on gene regulation, potentially in relationship to the physiology or timing of female reproductive maturation.

Granulosa cell subtypes vary in response to oxidized low-density lipoprotein as regards specific lipoprotein receptors and antioxidant enzyme activity

CONTEXT

The oxidized low-density lipoprotein (oxLDL) and its lectin-like oxLDL receptor-1 (LOX-1) are found in the follicular fluid and in granulosa cells. Lipoprotein receptors and antioxidant enzymes could differ in granulosa cell subtypes.

OBJECTIVE

Our aim was to reveal cell-specific responses under oxLDL treatment.

DESIGN AND SETTING

We conducted basic research at the Institute of Anatomy and the Clinic of Reproductive Medicine.

PATIENTS

Women undergoing in vitro fertilization therapy participated in the study.

MAIN OUTCOME MEASURES

Cultures of cytokeratin-positive/negative (CK(+)/CK(-)) granulosa cells and of cumulus cells were treated with 150 microg/ml oxLDL or native LDL under serum-free conditions for up to 36 h. Dead cells were determined by uptake of propidium iodide. LOX-1, toll-like receptor 4, and cluster of differentiation 36 (CD36) were examined in lysates by Western blots. The enzyme activities were determined in lysates and in supernatants.

RESULTS

Under oxLDL treatment, predominantly CK(+) cells underwent nonapoptotic cell death. Receptors showed a cell-specific pattern of up-regulation: toll-like receptor 4 in CK(+) cells, LOX-1 in CK(-) cells, and CD36 in cumulus cells. An antioxidant ranking occurred: superoxide dismutase activity in CK(+) cells, total glutathione in CK(-) cells, and catalase activity in cumulus cells. The supernatants of oxLDL-treated CK(+) cell cultures contained more catalase activity than in controls, whereas a moderate increase was noted for glutathione peroxidase (GPx) in supernatants of CK(-) and cumulus cells.

CONCLUSIONS

Catalase/GPx activity in the supernatants may be due to cell death or to secretion. Oxidative stress could be sensed by CK(+) cells and indicated by changes in catalase/GPx activity in the follicular fluid during ovarian disorders.