Exposure to 7,12-dimethylbenz[a]anthracene impacts ovarian DNA damage sensing and repair proteins differently in lean and obese female mice and weight loss may mitigate obesity-induced ovarian dysfunction.

Obesity impairs oocyte quality, fertility, pregnancy maintenance, and is associated with offspring birth defects. The model ovotoxicant, 7,12-dimethylbenz[a]anthracene (DMBA), causes ovarian DNA damage and follicle loss. Both DMBA-induced chemical biotransformation and the DNA damage response are partially attenuated in obese relative to lean female mice but whether weight loss could improve the DNA damage response to DMBA exposure has not been explored. Thus, at six weeks of age, C57BL/6 J female mice were divided in three groups: 1) Lean (L; n = 20) fed a chow diet for 12 weeks, 2) obese (O; n = 20) fed a high fat high sugar (HFHS) diet for 12 weeks and, 3) slim-down (S; n = 20). The S group was fed with HFHS diet for 7 weeks until attaining a higher body relative to L mice on week 7.5 and switched to a chow diet for 5 weeks to achieve weight loss. Mice then received either corn oil (CT) or DMBA (D; 1 mg/kg) for 7 d via intraperitoneal injection (n = 10/treatment). Obesity increased (P < 0.05) kidney and spleen weight, and DMBA decreased uterine weight (P < 0.05). Ovarian weight was reduced (P < 0.05) in S mice, but DMBA exposure increased ovary weight in the S mice. LC-MS/MS identified 18, 64, and 7 ovarian proteins as altered (P < 0.05) by DMBA in the L, S and O groups, respectively. In S and O mice, 24 and 8 proteins differed, respectively, from L mice. These findings support weight loss as a strategy to modulate the ovarian genotoxicant response.

Protective Effects of Platelet-rich plasma for in vitro Fertilization of Rats with Ovarian Failure Induced by Cyclophosphamide.

OBJECTIVE: Premature ovarian insufficiency (POI) contributes significantly to female infertility. Cyclophosphamide (CYC has adverse effects on folliculogenesis. Platelet-rich plasma (PRP) is an autologous product rich in many growth factors. We evaluated the protective effect of PRP on in vitro fertilization in female rats with CYC-induced ovarian damage. METHODS: Twenty-eight adult female Sprague-Dawley rats were randomly divided into four groups. Group 1 (control-sodium chloride 0.9%; 1 mL/kg, single-dose intraperitoneal [IP] injection); group 2 (CYC), 75 mg/kg, single-dose IP injection and sodium chloride 0.9% (1 mL/kg, single-dose IP injection); group 3 CYC plus PRP, CYC (75 mg/kg, single-dose and PRP (200 µl, single-dose) IP injection); and group 4 (PRP, 200 µl, single-dose IP injection). RESULTS: In the comparisons in terms of M1 and M2 oocytes, it was observed that the CYC group presented a significantly lower amount than the control, CYC/PRP, and PRP groups. (for M1, p = 0.000, p = 0.029, p = 0.025; for M2, p = 0.009, p = 0.004, p = 0.000, respectively). The number of fertilized oocytes and two-celled good quality embryos was found to be statistically significant between the CYC and control groups, CYC + PRP and PRP groups (p = 0.009, p = 0.001, p = 0.000 for oocytes, respectively. For embryos; p = 0.016, p = 0.002, p = 0.000). CONCLUSION: Platelet-rich plasma can protect the ovarian function against damage caused by CYC, and, in addition, it improves oocyte count and the development of embryos as a result of oocyte stimulation during the IVF procedure.

OBJETIVO: A insuficiência ovariana prematura (POI) contribui significativamente para a infertilidade feminina. A ciclofosfamida (CYC) tem efeitos adversos na foliculogênese. O plasma rico em plaquetas (PRP) é um produto autólogo rico em muitos fatores de crescimento. Avaliamos o efeito protetor do PRP na fertilização in vitro em ratas com lesão ovariana induzida por CYC. MéTODOS: Vinte e oito ratas Sprague-Dawley adultas foram divididas aleatoriamente em quatro grupos. Grupo 1 (controle - cloreto de sódio 0,9%; 1 mL/kg, injeção intraperitoneal [IP] em dose única); grupo 2 (CYC), 75 mg/kg, injeção IP de dose única e cloreto de sódio 0,9% (1 mL/kg, injeção ip de dose única); grupo 3 CYC + PRP, CYC (75 mg/kg, dose única e PRP (200 µl, dose única) injeção IP); e grupo 4 (PRP, 200 µl, injeção IP de dose única). RESULTADOS: Nas comparações em termos de ovócitos M1 e M2, observou-se que o grupo CYC apresentou uma quantidade significativamente menor que os grupos controle, CYC/PRP, e PRP. (Para M1, p = 0,000, p = 0,029, p = 0,025; para M2, p = 0,009, p = 0,004, p = 0,000, respectivamente). O número de oócitos fertilizados e embriões bicelulares de boa qualidade foi considerado estatisticamente significativo entre os grupos CYC e controle, CYC + PRP e grupos PRP (p = 0,009, p = 0,001, p = 0,000 para oócitos, respectivamente. Para embriões, p = 0,016, p = 0,002, p = 0,000). CONCLUSãO: O PRP pode proteger a função ovariana contra os danos causados pelo CYC e, além disso, proporciona melhora na contagem de oócitos e no desenvolvimento de embriões como resultado da estimulação ovariana durante o procedimento de fertilização in vitro.

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.

Development of a fertility risk calculator to predict individualized chance of ovarian failure after chemotherapy.

PURPOSE: To develop an innovative machine learning (ML) model that predicts personalized risk of primary ovarian insufficiency (POI) after chemotherapy for reproductive-aged women. Currently, individualized prediction of a patient's risk of POI is challenging. METHODS: Authors of published studies examining POI after gonadotoxic therapy were contacted, and six authors shared their de-identified data (N = 435). A composite outcome for POI was determined for each patient and validated by 3 authors. The primary dataset was partitioned into training and test sets; random forest binary classifiers were trained, and mean prediction scores were computed. Institutional data collected from a cross-sectional survey of cancer survivors (N = 117) was used as another independent validation set. RESULTS: Our model predicted individualized risk of POI with an accuracy of 88% (area under the ROC 0.87, 95% CI: 0.77-0.96; p < 0.001). Mean prediction scores for patients who developed POI and who did not were 0.60 and 0.38 (t-test p < 0.001), respectively. Highly weighted variables included age, chemotherapy dose, prior treatment, smoking, and baseline diminished ovarian reserve. CONCLUSION: We developed an ML-based model to estimate personalized risk of POI after chemotherapy. Our web-based calculator will be a user-friendly decision aid for individualizing risk prediction in oncofertility consultations.

APOE4 genotype exacerbates the impact of menopause on cognition and synaptic plasticity in APOE-TR mice.

The impact of sex and menopausal status in Alzheimer's disease remains understudied despite increasing evidence of greater female risk, particularly in APOE4 carriers. Utilizing female APOE-TR mice maintained on a high-fat diet background we induced ovarian failure through repeated VCD injections, to mimic human menopause. At 12 months of age, recognition memory and spatial memory were assessed using object recognition, Y-maze spontaneous alternation, and Barnes maze. A VCD*genotype interaction reduced the recognition memory (P < .05), with APOE4 VCD-treated animals unable to distinguish between novel and familiar objects. APOE4 mice displayed an additional 37% and 12% reduction in Barnes (P < .01) and Y-maze (P < .01) performance, indicative of genotype-specific spatial memory impairment. Molecular analysis indicated both VCD and genotype-related deficits in synaptic plasticity with BDNF, Akt, mTOR, and ERK signaling compromised. Subsequent reductions in the transcription factors Creb1 and Atf4 were also evident. Furthermore, the VCD*genotype interaction specifically diminished Ephb2 expression, while Fos, and Cnr1 expression reduced as a consequence of APOE4 genotype. Brain DHA levels were 13% lower in VCD-treated animals independent of genotype. Consistent with this, we detected alterations in the expression of the DHA transporters Acsl6 and Fatp4. Our results indicate that the combination of ovarian failure and APOE4 leads to an exacerbation of cognitive and neurological deficits.

Effects of coenzyme Q10 on ovarian surface epithelium-derived ovarian stem cells and ovarian function in a 4-vinylcyclohexene diepoxide-induced murine model of ovarian failure.

BACKGROUND: Several studies have shown that coenzyme Q10 (CoQ10) can rescue ovarian aging and that ovarian surface epithelium (OSE)-derived ovarian stem cells (OSCs) are useful for treating infertility due to ovarian aging. However, few studies have examined the effect of CoQ10 on OSCs. This study was aimed to investigate whether CoQ10 activates OSCs and recovers ovarian function in a 4-vinylcyclohexene diepoxide (VCD)-induced mouse model of ovarian failure. METHODS: Forty female C57BL/6 mice aged 6 weeks were randomly divided into four groups (n = 10/group): a control group administered saline orally, a CoQ10 group administered 150 mg/kg/day of CoQ10 orally in 1 mL of saline daily for 14 days, a VCD group administered 160 mg/kg/day of VCD i.p. in 2.5 mL of saline/kg for 5 days, and a VCD + CoQ10 group administered VCD i.p. for 5 days injection and CoQ10 (150 mg/kg/day) orally for 14 days. After treatment, follicle counts were evaluated by hematoxylin and eosin (H&E) staining, and ovarian mRNA expressions of Bmp-15, Gdf-9, and c-Kit were examined by quantitative real-time PCR. Serum FSH, AMH, and ROS levels were also measured. Oocyte-like structure counts and the expressions of Oct-4 and MVH were also evaluated after culturing OSE for 3 weeks. In a second experiment, 32 female mice were administered CoQ10 as described above, induced to superovulate using PMSG and hCG, and mated. Numbers of zygotes and embryo development rate were examined. RESULTS: Postcultured OSE showed significant increases in the numbers of oocyte-like structure and that the expression of Oct-4 and MVH were higher in the VCD + CoQ10 group than in the VCD group (p < 0.05). Numbers of surviving follicles from primordial to antral follicles, numbers of zygotes retrieved and embryo development rate to blastocyst were significantly greater in the VCD + CoQ10 group than in the VCD group (p < 0.01). Serum AMH level and ovarian expressions of Bmp-15, Gdf-9 and c-Kit were also significantly greater in the VCD + CoQ10 group than in the VCD group (p < 0.05). In contrast, serum ROS level was significantly lower in the VCD + CoQ10 group than in the VCD group (p < 0.05). CONCLUSION: This study shows that CoQ10 stimulates the differentiation of OSE-derived OSCs and confirms that CoQ10 can reduce ROS levels and improve ovarian function and oocyte quality in mice with VCD-induced ovarian failure.

Protective effect of Coenzyme Q10 on oxidative ovarian and uterine damage induced by methotrexate in rats.

Methotrexate (MTX) has toxic effects on the uterus and ovaries via oxidative stress. Coenzyme Q10 (CoQ10) is an important component in electron transport in the mitochondria and an antioxidant in cellular metabolism through the inhibition of lipid peroxidation. The aim of this study was to investigate the preventive effects of CoQ10 on MTX-induced utero-ovarian damage and oxidative stress in rats.In this experimental study, 30 albino Wistar female rats were divided randomly into three groups. Once a day for a month, 10 mg/kg of CoQ10 was orally administered to the rats in the MTX+CoQ10 group, while the same volume of olive oil was administered orally to the other two groups. One hour thereafter, 20 mg/kg of MTX was injected intraperitoneally into the rats in the MTX and MTX+CoQ10 groups; the remaining group was the control. At the end of the month, biochemical and histopathologic examinations were performed on the extracted uteri and ovaries. In the uterine ovarian tissues of the animals in the MTX group, there was an increase in oxidative stress mediators and a decrease in antioxidant and anti-inflammatory mediators, but these trends were reversed in the MTX+CoQ10 group, demonstrating the antioxidant effects of CoQ10. MTX leads to oxidative stress-related ovarian and uterine injury, and CoQ10 may be useful for protecting ovarian and uterine tissue from such injury.

The protective effects of resveratrol pretreatment in cyclophosphamide-induced rat ovarian injury: an vivo study.

OBJECTIVES: To explore whether resveratrol (Res) pretreatment could exert a protective effect on cyclophosphamide (Cy) induced ovarian toxicity in a rat model. METHODS: Twenty-four female 7-week old Sprague-Dawley rats were randomly divided into four groups: Con, administered with vehicle solutions; Cy, treated with Cy; Res + Cy, treated with Cy + Res combined; Res, treated with Res. After 21 d of treatments, the rats were euthanized and blood samples were collected to evaluate the levels of anti-Müllerian hormone (AMH). The Ovaries were processed for immunohistochemical and western blotting. RESULTS: Cy-treat caused the decrease of body weights and ovarian weight. AMH was lower in Cy group, whereas AMH levels were similar among other groups. Histomorphology showed a large number of primordial follicles were activated in Cy groups, whereas the primordial follicles were inhibited in the Res and Res + Cy groups. The expressions of Sirt1, Foxo3a were up-regulated and p53, Caspase-3, and Bax were down-regulated in Res + Cy and Res groups (p < .05). CONCLUSIONS: Res can prevent the primordial follicle activation and decrease apoptosis induced by Cy. Res may be an effective protection for ovarian function during chemotherapy, which means a new nonsurgical application for protection of ovarian reserve.

An assessment of the protective effect of gonadotropin-releasing hormone agonist and antagonist on bleomycin-induced ovarian toxicity in rats.

The aim of this study is to evaluate the effect of GnRH agonist or GnRH antagonist therapy on bleomycin-administered rats by examining ovarian follicle counts and AMH levels. A total of 30 female Wistar albino rats aged 4-6 months were randomly divided into 4 groups. First, an intramuscular injection of bleomycin (30 mg/m2) was administered to all except the control group on the 1st, 8th and 15th days. The control group (Group I) was administered 0.1 mL intramuscular saline on those days. The bleomycin group (Group II) was followed up without any further treatment. The bleomycin + GnRH agonist group (Group III) was administered subcutaneous GnRH agonist triptorelin (1 mg/kg) at the same time as the bleomycin injections. The bleomycin + GnRH antagonist group (Group IV) was administered 1 mg/kg cetrorelix acetate subcutaneously, concurrently with the bleomycin. Although AMH levels were lower in the bleomycin group than in all the other groups, there was no statistically significant difference between the groups in terms of AMH levels (p > .05). In the bleomycin + cetrorelix acetate and bleomycin + triptorelin groups, significantly higher primordial, secondary and tertiary follicle counts were determined compared to the bleomycin group (p < .001). In conclusion the harmful effects of bleomycin on ovarian reserve can be reduced by the simultaneous administration of GnRH agonist or GnRH antagonist.

Involvement of PTEN and FOXO3a Proteins in the Protective Activity of Protocatechuic Acid Against Cisplatin-Induced Ovarian Toxicity in Mice.

The present study evaluated the effects of protocatechuic acid (PCA) after cisplatin-induced ovarian toxicity in mice and if PTEN and FOXO3a proteins are involved in PCA action. The mice were divided into five experimental groups (five animals per group) and treated once a day for 3 days as follows: (1) the control group was pretreated with oral administration (o.p.) of saline solution, followed by an intraperitoneal (i.p.) injection of saline solution. The other groups were pretreated (o.p.) with (2) saline solution (cisplatin group), (3) N-acetylcysteine (150 mg/kg of body weight), or with (4) 20 or (5) 50 mg/kg body weight of PCA, followed by 5 mg/kg body weight (i.p.) of cisplatin. Next, the ovaries were destined to histological (morphology and activation), immunohistochemical (PCNA and cleaved caspase-3 expression), and fluorescence (reactive oxygen species [ROS], glutathione [GSH], and active mitochondria levels) analyses. Moreover, the immunoreactivity for p-PTEN and p-FOXO3a was evaluated to investigate a potential mechanism by which PCA could prevent the cisplatin-induced ovarian damage. Pretreatment with N-acetylcysteine or 20 mg/kg PCA before cisplatin preserved the percentage of normal follicles and cell proliferation as observed in the control, reduced apoptosis and ROS levels, and showed higher active mitochondria and GSH levels than the cisplatin treatment (P < 0.05). Moreover, pretreatment with 20 mg/kg PCA decreased cisplatin-induced p-PTEN and increased (P < 0.05) nuclear export of p-FOXO3a. In conclusion, PCA at 20 mg/kg reduced apoptosis, maintained cell proliferation and mitochondrial function, reduced ROS production, and increased GSH expression likely through the involvement of PTEN and FOXO3a proteins.

Putative adverse outcome pathways for female reproductive disorders to improve testing and regulation of chemicals.

Modern living challenges female reproductive health. We are witnessing a rise in reproductive disorders and drop in birth rates across the world. The reasons for these manifestations are multifaceted and most likely include continuous exposure to an ever-increasing number of chemicals. The cause-effect relationships between chemical exposure and female reproductive disorders, however, have proven problematic to determine. This has made it difficult to assess the risks chemical exposures pose to a woman's reproductive development and function. To address this challenge, this review uses the adverse outcome pathway (AOP) concept to summarize current knowledge about how chemical exposure can affect female reproductive health. We have a special focus on effects on the ovaries, since they are essential for lifelong reproductive health in women, being the source of both oocytes and several reproductive hormones, including sex steroids. The AOP framework is widely accepted as a new tool for toxicological safety assessment that enables better use of mechanistic knowledge for regulatory purposes. AOPs equip assessors and regulators with a pragmatic network of linear cause-effect relationships, enabling the use of a wider range of test method data in chemical risk assessment and regulation. Based on current knowledge, we propose ten putative AOPs relevant for female reproductive disorders that can be further elaborated and potentially be included in the AOPwiki. This effort is an important step towards better safeguarding the reproductive health of all girls and women.

Cilostazol protects against cyclophosphamide-induced ovarian toxicity in female rats: role of cAMP and HO-1.

Purpose: Cancer rates have been increased among women of reproductive age nowadays. Hence, many young female will be exposed to chemotherapeutic agents as cyclophosphamide (CP), carrying the hazards on female fertility. Cilostazol is a selective phosphodiesterase-3 inhibitor drug which exhibits antioxidant, anti-inflammatory, and anti-apoptotic activities. We aimed in this study to explore the possible protective effects of cilostazol against CP-induced ovarian damage in female rats.Methods: Cilostazol (10 mg/kg/day) was administered orally for 10 days in presence and absence of CP (150 mg/kg IP single dose) treatment. Serum follicle-stimulating hormone (FSH), luteinizing hormone (LH), estrogen (E2), and anti-Müllerian hormone (AMH) levels were determined. Ovarian oxidative stress parameters along with inflammatory biomarkers were measured. 3,5-Cyclic adenosine monophosphate (cAMP) ovarian level was detected. Ovarian histopathological examination and caspase-3 immunohistochemical study were evaluated.Results: CP-treated rats showed a significant increase in serum levels of FSH and LH with decreased serum E2 and AMH levels with an increase in the ovarian inflammatory and oxidative stress biomarkers besides a significant decrease in cAMP ovarian level with an evident histopathological picture of ovarian damage and a high caspase-3 immunoexpression. Cilostazol pretreatment significantly restored the distributed hormonal levels, the oxidative stress and inflammatory biomarkers to their normal levels with marked improvement in histopathological picture of ovarian damage with a significant decrease in caspase-3 immunoexpression.Conclusions: These data suggest that cilostazol protects against CP- induced ovarian damage, which may be related to an increase in cAMP with subsequent anti-inflammatory, antioxidant, and anti-apoptotic properties.

Protective effect of Tualang honey against cadmium-induced morphological abnormalities and oxidative stress in the ovary of rats.

BACKGROUND: To investigate the protective effects of Tualang honey against the toxicity effects induced by cadmium (Cd) on the ovary. METHODS: A total of 32 female Sprague Dawley rats were taken and randomly divided into four groups (n = 8). Throughout the experimental period of 6 weeks, negative control-NC (vehicle deionized water), positive control-CD (Cd at 5 mg/kg), Tualang honey followed by Cd exposure-TH (Tualang honey at 200 mg/kg and Cd at 5 mg/kg) and Tualang honey control-THC (Tualang honey at 200 mg/kg) groups, were administered orally on a daily basis. RESULTS: Rats exposed to Cd were significantly higher in ovarian weight, number of antral and atretic follicles as compared to the NC group. The disruptive effects of Cd on ovarian follicles were associated with a disruption in gonadotropin hormones and decreases in follicular stimulating hormone (FSH) and luteinizing hormone (LH). Moreover, a significant formation of oxidative stress in ovarian Cd-exposed rats has been proven by increasing the level of lipid peroxidation products (malondialdehyde) and decreasing the levels of enzymatic antioxidant (catalase). Interestingly, a daily supplementation of high antioxidant agents such as Tualang honey in these animals, caused significant improvements in the histological changes. Additionally, less atretic follicles were observed, restoring the normal level of LH and FSH (P < 0.001), and normalizing the ovarian malondialdehyde (P < 0.05) and catalase levels in comparison with CD group (P < 0.05). CONCLUSIONS: Tualang honey has protective effects against Cd-induced ovarian toxicity by reducing morphological abnormalities, restoring the normal levels of gonadotropin hormones and stabilizing equilibrium levels of lipid peroxidation and antioxidant enzyme in ovaries of rats.

The protective effect of platelet-rich plasma administrated on ovarian function in female rats with Cy-induced ovarian damage.

PURPOSE: We evaluated the protective effect of PRP on ovarian function in female rats with cyclophosphamide (Cy)-induced ovarian damage. METHODS: Thirty-two adult female Sprague-Dawley rats were randomly divided into four groups. Group 1 (control-sodium chloride 0.9%; 1 mL/kg, single-dose ip injection), group 2 (Cy); 75 mg/kg, single-dose ip injection and sodium chloride 0.9% (1 mL/kg, single-dose ip injection), group 3 Cy plus PRP, Cy (75 mg/kg, single-dose and PRP (200 µl, single-dose) ip injection), group 4 (PRP, 200 µl, single-dose ip injection). Primordial, antral, and atretic follicle counts; serum anti-Müllerian hormone (AMH) levels; AMH-positive granulosa cells; and gene expression analysis of Ddx4 were assessed. RESULTS: Serum AMH levels were significantly lower in group 2 compared to groups 1, 3, and 4 (p < 0.01, p < 0.01, and p = 0.04, respectively). A significant difference was found in the primordial, primary, secondary, antral, and atretic follicle counts between all groups (p < 0.01). There was a statistically significant difference in AMH-positive staining primary, secondary, and antral follicles count between the groups (p < 0.01). There was a statistically significant difference in primary, secondary, and antral AMH positive staining follicle intensity score between the groups (p < 0.01). Ddx4 expression in group 4 was highest compared to other groups. CONCLUSION: Our study may provide evidence that PRP could protect ovarian function against ovarian damage induced by Cy. It could lead to improved primordial, primary, secondary, and antral follicle numbers.

Ovarian Follicle Depletion Induced by Chemotherapy and the Investigational Stages of Potential Fertility-Protective Treatments-A Review.

Ovarian follicle pool depletion, infertility, and premature menopause are all known sequelae of cancer treatment that negatively impact the quality of life of young cancer survivors. The mechanisms involved in this undesired iatrogenic ovarian damage have been intensively studied, but many of them remain unclear. Several chemotherapeutic drugs have been shown to induce direct and indirect DNA-damage and/or cellular stress, which are often followed by apoptosis and/or autophagy. Damage to the ovarian micro-vessel network induced by chemotherapeutic agents also seems to contribute to ovarian dysfunction. Another proposed mechanism behind ovarian follicle pool depletion is the overactivation of primordial follicles from the quiescent pool; however, current experimental data are inconsistent regarding these effects. There is great interest in characterizing the mechanisms involved in ovarian damage because this might lead to the identification of potentially protective substances as possible future therapeutics. Research in this field is still at an experimental stage, and further investigations are needed to develop effective and individualized treatments for clinical application. This review provides an overview of the current knowledge and the proposed hypothesis behind chemotherapy-induced ovarian damage, as well as current knowledge on possible co-treatments that might protect the ovary and the follicles from such damages.

Role of epigenetic regulation of Igf2 and H19 in 2,3,7,8-Tetrachlorobenzo-p-dioxin (TCDD)-induced ovarian toxicity in offspring rats.

2,3,7,8-Tetrachlorobenzo-p-dioxin (TCDD) exposure during embryonic gonadal sex determination had been demonstrated to harm the ovarian development. However, its mechanism was unclear and possibly related to epigenetic regulation. In the present study, the pregnant rats were treated with TCDD (100 ng/kg/day or 500 ng/kg/day) or only vehicle and corn oil on the day 8-14 of gestation through the gavage with a stainless-steel feeding needle. The vaginal opening time and estrous cycle of female offspring rats (F1) were monitored twice a day. The ovarian histology, follicle count, real-time PCR, Western Blotting and DNA methylation analysis for Igf2 and H19 were carried out. The results showed that maternal TCDD exposure disrupted estrous cyclicity, resulted in aberrant concentration of serum E2 and FSH, and affected the number of primordial follicles, secondary follicles and corpus luteum. However, TCDD had no effect on the number of primary follicles and atresia follicles. Furthermore, the mRAN expression of imprinted genes Igf2 and H19 was down-regulated, and the IGF2 protein was also down-regulated. TCDD exposure did not alter the mean methylation rate of Igf2 DMR2 and H19 ICR, and only some CpG sites throughout them were hypermethylated in high-dose TCDD rats. In conclusion, maternal exposure of TCDD could affect the ovary development and functions which were possibly associated with down-regulation expression of IGF2 and H19. However, it was not entirely clear whether the impairment of ovary by TCDD was related to the methylation pattern of Igf2 and H19 ICR.

Role of PCSK9 in lipid metabolic disorders and ovarian dysfunction in polycystic ovary syndrome.

BACKGROUND: Proprotein convertase subtilisin/kexin type 9 (PCSK9) plays a critical role in the cholesterol metabolism by negatively regulating the low-density lipoprotein receptor (LDLR). Lipid metabolic and ovarian disorders are the common clinical manifestation of polycystic ovary syndrome (PCOS). Here, we intended to elucidate the role of PCSK9 in the pathogenesis of PCOS conducted on a human population in case-control design and animal part in an interventional study. METHODS: We firstly investigated the serum levels of PCSK9 in 46 PCOS patients compared with 49 healthy women as controls, and then developed a PCOS mouse model induced by dehydroepiandrosterone (DHEA) and a high-fat diet (HFD) to determine the role of PCSK9 in abnormal lipid metabolism and ovarian dysfunction of PCOS in four groups (n = 40 per group): control, PCOS mice, PCOS plus alirocumab group, and PCOS plus vehicle group. The expression of PCSK9 in their serum, hepatic and ovarian tissues, serum lipid profiles and hormones were measured. Additionally, mRNA and protein expression levels of LDLR in hepatic and ovarian tissues, ovarian morphology and function were determined. Finally, we used freshly isolated theca-interstitial cells (TICs) and granulosa cells (GCs) from prepubertal normal mice to explore the effect of PCSK9 on LDL uptake of the cells. RESULTS: Serum PCSK9 concentrations were higher in PCOS patients than normal controls (P < 0.05). The PCOS model mice exhibited significantly increased serum levels of total cholesterol (TC), LDL-C and high-density lipoprotein-cholesterol (HDL-C; P < 0.001, P < 0.001, P = 0.0004, respectively). Moreover, the serum PCSK9 protein level was significantly increased in PCOS mice (P = 0.0002), which positively correlated with serum LDL-C (r = 0.5279, P = 0.0004) and TC (r = 0.4151, P = 0.035). In both liver and ovary of PCOS mice, PCSK9 mRNA and protein levels were significantly increased (P < 0.05), but LDLR levels were significantly decreased (P < 0.05). Furthermore, alirocumab inhibiting PCSK9 partly increased in LDLR expression in both liver and ovary in PCOS mice, also ameliorated the lipid metabolic disorders and pathological changes of ovarian morphology and function and serum reproductive hormones but not in the PCOS plus vehicle group. In vitro experiment, recombinant PCSK9 decreased LDL uptake in TICs and GCs (P < 0.001, P = 0.0011, respectively), which were partly reversed by alirocumab (P < 0.001, P = 0.012, respectively). CONCLUSION: Abnormal high expression of PCSK9 in the blood, liver and ovary may be involved in the pathogenesis of PCOS by affecting lipid metabolism and ovarian function, and the inhibition of PCSK9 may partly reverse the pathological changes of PCOS. Our research suggests a possibility of PCSK9 as a new attractive target for diagnosis and treatment of PCOS.

Non-steroidal anti-inflammatory drug induces luteinized unruptured follicle syndrome in young female juvenile idiopathic arthritis patients.

To assess prospectively luteinized unruptured follicle (LUF) syndrome in juvenile idiopathic arthritis (JIA) patients with and without non-steroidal anti-inflammatory drugs (NSAIDs) and healthy controls. Twenty-three adolescent and young adult female JIA patients (ILAR criteria) and 11 female healthy subjects were studied by pelvic ultrasound monitoring for follicular development and ovulation in one menstrual cycle. LUF syndrome was prospectively investigated by pelvic ultrasound with a dominant ovarian follicle without signs of follicular rupture, with elevation of serum progesterone in the luteal phase of the menstrual cycle and luteinizing hormone (LH) detected in the urine. Comparison between JIA patients with (n = 8) vs. without NSAIDs (n = 15) and healthy controls (n = 11) revealed that LUF syndrome was significantly higher in the former group (2 (25%) vs. 0% vs. 0%, p = 0.049). These two patients with LUF syndrome had normal menstrual cycles without reduced ovarian reserve, and they were under naproxen 500 mg bid during the menstrual cycle. Disease duration was comparable in JIA with and without NSAIDs [19.8 (4.4-25) vs. 13 (3.1-33) years, p = 0.232]. Further comparison between JIA patients with and without NSAIDs and healthy controls showed similar mean anti-Müllerian hormone levels (p = 0.909), estradiol (p = 0.436), FSH (p = 0.662), LH (p = 0.686), and mean antral follicle count (p = 0.240) and ovarian volume (p = 0.363). No differences were evidenced in three groups regarding Caucasian race, body mass index, duration, and length of menstrual cycles (p > 0.05). This is the first study to identify that JIA patients have a high frequency of LUF without impaired ovarian reserve. Future prospective studies are necessary to determine if chronic/continuous use of NSAIDs in JIA will have an impact in these patients' fertility.

Effect of platelet-rich plasma (PRP) on ovarian structures in cyclophosphamide-induced ovarian failure in female rats: a stereological study.

BACKGROUND: Ovarian failure is diagnosed by ovarian destruction and reducing sex hormonal levels. Platelet-rich plasma (PRP) contains several growth factors that induce tissue repair and may induce folliculogenesis. OBJECTIVE: This study evaluates the effect of PRP on ovarian structures and function in cyclophosphamide (Cy)-induced ovarian failure in female rats by a stereological method. METHODS: Thirty-two adult female rats were divided into four groups (Control, Cy, Cy + PRP, and PRP). Female infertility was induced by Cy (75 mg/kg, single dose, intraperitoneally). Animals were treated by PRP which was obtained from age-matched male rats (200 µL, single dose, intraperitoneally). Blood samples were collected for measurement of hormones. The animals were dissected and the right ovaries were removed, fixed, sectioned, and stained by H&E. Stereological methods were used to estimate cortex and medulla volume, and the number and diameter of follicles, follicular cell, and oocyte using light microscopy. RESULTS: Cyclophosphamide had the maximum effect in decreasing on cortex volume, the pre-antral follicles number, a diameter of follicular cells and oocyte diameter in the antral follicle and the reduction of estradiol and progesterone levels compared with the control group. PRP had a dominant positive effect on the ovarian cortex volume, pre-antral follicles number and antral follicle diameter relative to the control group. PRP also decreased oocyte diameter in pre-antral follicle in infertile animals (p < 0.001). CONCLUSION: It seems that PRP has a protective effect on ovarian failure in the infertile female rat model.