Oxytocin improves follicular reserve in a cisplatin-induced gonadotoxicity model in rats

Posthatch developmental changes in the ovary with emphasis on follicular development and atresia in the native chicken (Uttara fowl) of Uttarakhand, India

This experiment was designed to investigate the postnatal development of the ovary in the Uttara fowl chicken and was conducted on 54 apparently healthy female birds divided into different age groups, namely Day 1 and Weeks 1, 4, 8, 12, 16, 20, 24, 28 with six birds each. During postnatal development, the left ovary gradually increased in size and complexity. The segmentation of the ovary started by 4 weeks, follicular eruption by 8 weeks, small liquor follicles (1-5 mm) appeared by 16 weeks, pre-hierarchical follicles by 20 weeks and hierarchical follicles by 24 weeks of age. The cortex was distinctly differentiated from the medulla in the early stage of ovarian development. However, the division between cortex and medulla was gradually obscured with age (transitional stage) and distinction was completely lost in the mature ovary. The different stages of follicular development in the chicken ovary were classified as primordial, primary, growing at Stage I, II and III stromal follicles besides pre-hierarchical and hierarchical surface follicles. The primordial and primary follicles showed cytoplasmic sudanophilic substances, especially in the Balbiani's yolk body, indicating the presence of lipids (Sudan Black B) with no activity for neutral polysaccharides (periodic acid Schiff method). It was observed that apoptotic changes may affect any stage of developing follicle resulting in arrested growth and atrophy. An early form of follicular atresia was the fate of the growth-arrested primordial and primary follicles, whereas the glandular form of atresia was commonly observed in growing follicles arrested at Stages I and II. The scanning electron micrographs unveiled the follicles as hollow oval structures with a follicular lumen lined by the perivitelline membrane (glycoprotein membrane) having lacunae giving a honeycomb-like appearance.

Fibromodulin is involved in autophagy and apoptosis of granulosa cells affecting the follicular atresia in chicken

Follicular atresia is an important cause of reproductive decline in egg-laying hens. Therefore, a better understanding of the regulation mechanism of follicle atresia in poultry is an important measure to maintain persistent high egg performance. However, how the role of the regulatory relationship between autophagy and apoptosis in the intrafollicular environment affects the follicular atresia of chickens is remain unclear. The objective of this study was to explore the regulatory molecular mechanisms in regard to follicular atresia. 20 white leghorn layers (32-wk-old) were equally divided into 2 groups. The control group was fed freely, and the experimental group induced follicular atretic by fasting for 5 d. The results showed that the expression of prolactin (PRL) levels was significantly higher in the fasted hens, while the levels of luteinizing hormone (LH) and follicle stimulating hormone (FSH) were lower. Most importantly, RNA sequencing, qPCR, and Western blotting detected significantly elevated levels of autophagy and apoptosis markers in atresia follicles. Interestingly, we found that fibromodulin (FMOD) levels was significantly lower in follicles from fasted hens and that this molecule had an important regulatory role in autophagy. FMOD silencing significantly promoted autophagy and apoptosis in granulosa cells, resulting in hormonal imbalance. FMOD was found to regulate autophagy via the transforming growth factor beta (TGF-β) signaling pathway. Our results suggest that the increase in autophagy and the imbalance in internal homeostasis cause granulosa cell apoptosis, leading to follicular atresia in the chicken ovary. This finding could provide further insight into broodiness in chicken and provide avenues for further improvements in poultry production.

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.

Protective effect of oxytocin on a methotrexate-induced ovarian toxicity model

PURPOSE

Although cancer predominantly affects people at older ages, a substantial number of patients, like breast cancer patients, are diagnosed before they have completed their families or even before giving birth. Furthermore, cytotoxic chemotherapy may be required in addition to treat cancer survivors. The present study was conducted to investigate the protective effect of oxytocin (OT) on methotrexate (MTX)-induced ovarian toxicity in rats.

METHODS

Eighteen adult female Sprague-Dawley rats were used in the study. All rats were divided randomly into three groups. The control group (n = 6) received no treatment. The remaining 12 rats received a single dose of 20 mg/kg of MTX. Half of the rats (n = 6) were treated with 1 mg/kg/day of saline, and the other half (n = 6) were treated with 160 µg/kg/day of OT for 21 days. Then, blood samples were collected for biochemical analysis, and an ovariectomy was performed for histopathological examination.

RESULTS

Plasma malondialdehyde (MDA) and transforming growth factor-β (TGF-β) levels were significantly lower in the MTX + OT group compared to the MTX + saline group (p = 0.000036 for MDA; p = 0.0044 for TGF-β). AMH levels were also significantly higher in the MTX + OT group than in the MTX + saline group (p = 0.000036). The ovarian fibrosis percent was also notably lower in the MTX + OT group than in the MTX + saline group (p = 0.000036).

CONCLUSION

On the basis of these findings, OT is a promising agent for ameliorating harmful effects of MTX on rat ovaries in an experimental model.

Investigation of the preventive effects of dehydroepiandrosterone (DHEA) and Caffeic acid phenethyl ester (CAPE) on cisplatin-induced ovarian damage in rats

To investigate whether Dehydroepiandrosterone (DHEA) and Caffeic acid phenethyl ester (CAPE) had any preventive effect against the ovarian damage caused by cisplatin (CP) (cis-diamminedichloroplatinum) in rats. On the first day ovaries were removed, Anti-Müllerian hormone (AMH) was measured (Group1, n:6), in the other groups 7.5 mg/kg cisplatin was administered intraperitoneally. In Group 2 (n = 6), 0.1 ml saline, in Group 3 (n = 5), 20 umol/kg CAPE, in Group 4 (n = 7), DHEA 6 mg/kg were administered every day. On the 10th day, ovaries were removed, AMH was measured. Ovary reserve (primordial/primary/secondary/tertiary/atretic follicles, AMH), ovarian damage scores (follicular degeneration, congestion, hemorrhage, edema, inflammation) were compared. The number of tertiary follicles were statistically high in the CAPE group (p = .015), the inflammation score in the DHEA group (p = .012), AMH level (p = .009) in the control group. The lowest number of atretic follicles (AF) was in the control group, while the highest number of AF was in the DHEA group (p = .002). Significant decreases in AF were the case in the cisplatin and DHEA groups compared to the control group (p < .008). The AMH values had the highest positive correlation with the number of primordial follicles and the highest negative correlation with the number of AF. The cut off point for AMH was 1.57 ng/ml as an indicator of low ovarian reserve. Cisplatin causes total damage and increased numbers of AF on the ovary. Depending on this, AMH levels fall. These negative effects of cisplatin are not obstructed by CAPE or DHEA, and may even be increased by DHEA.

Oxytocin in the tumor microenvironment is associated with lower inflammation and longer survival in advanced epithelial ovarian cancer patients

BACKGROUND

Prior research demonstrates a protective role for oxytocin in ovarian cancer based on its anti-proliferative, anti-migratory, and anti-invasive effects in vitro and in vivo. However, the role of endogenous oxytocin has not been examined in ovarian cancer patients. Oxytocin also has anti-inflammatory properties that have not been examined in cancer. The purpose of this investigation was to examine relationships between endogenous oxytocin, tumor-associated inflammation (interleukin-6), and survival in advanced epithelial ovarian cancer patients.

METHODS

Tumor microenvironment (ascites) and plasma oxytocin levels were analyzed via ELISA on extracted samples obtained from 79 patients. In vitro models were used to characterize oxytocin and oxytocin receptor expression in four ovarian cancer cell lines and to investigate direct anti-inflammatory effects of oxytocin on tumor cell secretion of interleukin-6. High and variable levels of oxytocin were observed in ascites, up to 200 times greater than in plasma. Higher levels of ascites oxytocin were associated with lower levels of systemic and tumor-associated interleukin-6, an inflammatory cytokine implicated in ovarian tumor progression. Oxytocin also attenuated interleukin-6 secretion from multiple ovarian tumor cell lines in vitro. Higher levels of ascites oxytocin were associated with a significant survival advantage and statistical mediation analyses suggested this effect was partially mediated by interleukin-6.

CONCLUSIONS

These data identify a previously unacknowledged hormone in the ovarian tumor microenvironment and provide initial evidence that oxytocin has protective effects in ovarian cancer via anti-inflammatory mechanisms. Future studies should examine the therapeutic utility of oxytocin.

Could erythropoietin reduce the ovarian damage of cisplatin in female rats?

The aim of this study is to investigate whether erythropoietin (EPO) can reduce the ovarian damage of cisplatin or not. Thirty, female, Wistar-Albino rats were used in the study. Control group (N = 10): Intraperitoneal saline infusion, Cisplatin group (N = 10): Intraperitoneal 7 mg/kg cisplatin, Cisplatin + EPO group (N = 10): Intraperitoneal 7 mg/kg cisplatin and subcutaneous 200 IU/kg/day EPO. Serum AMH concentrations were measured by enzyme-linked immunosorbent assay kit of AMH. Follicular counts were evaluated according to mean diameter of the follicles. Ovarian damage; including follicular cell degeneration, vascular congestion, hemorrhage, and inflammation was scored histologically using a graduated scale. Posttreatment AMH levels of cisplatin group were significantly lower than control and cisplatin + EPO groups. In cisplatin group, there was a significant decrement in posttreatment AMH level compared to pretreatment AMH level. The total damage score of cisplatin group was significantly higher than scores of control and cisplatin + EPO groups. The mean primordial follicle counts of control and cisplatin + EPO groups were significantly higher than that of cisplatin group (p = .007 and p = .003). The results of this study revealed that EPO administration to cisplatin chemotherapy could ameliorate the ovarian damage. Erythropoietin administration to chemotherapeutic agents might suggest to protect ovarian failure and infertility.

Chronic intermittent hypoxia induces hormonal and male sexual behavioral changes: Hypoxia as an advancer of aging

Sleep apnea is a common sleep disorder characterized by intermittent periods of low blood oxygen levels. The risk for sleep apnea increases with age and is more prevalent in men than women. A common comorbidity of sleep apnea includes male sexual dysfunction, but it is not clear if a causal relationship exists between sleep apnea and sexual dysfunction. Possible mechanisms that link these two disorders include oxidative stress and testosterone. Oxidative stress is elevated in clinical patients with sleep apnea and in rodents exposed to chronic intermittent hypoxia (CIH), an animal model for apnea-induced hypopnea. Further, oxidative stress levels increase with age. Therefore, age may play a role in sleep apnea-induced sexual dysfunction and oxidative stress generation. To investigate this relationship, we exposed gonadally intact 3 (young) and 12 (middle-aged) month old male F344/BN F1 hybrid male rats to 8 days of CIH, and then examined male sexual function. Plasma was used to assess circulating oxidative stress and hormone levels. Middle-aged male rats had lower testosterone levels with increased sexual dysfunction and oxidative stress, independent of CIH. However, CIH decreased testosterone levels and increased sexual dysfunction and oxidative stress only in young gonadally intact male rats, but not in gonadectomized young rats with physiological testosterone replacement. In sum, CIH had a greater impact on younger gonadally intact animals, with respect to sexual behaviors, testosterone, and oxidative stress. Our data indicate CIH mimics the effects of aging on male sexual behavior in young gonadally intact male rats.

Antagonistic Effect of Oxytocin and Tacrolimus Combination on Adipose Tissue - Derived Mesenchymal Stem Cells: Antagonistic effect of oxytocin and tacrolimus

Tacrolimus (FK506) is a chemotherapeutic agent, which uses calcineurin pathway via inhibiting the stimulation of T cells to prevent the formation of immune response in the recipient individual in organ transplants. FK506 is mainly metabolized in the liver by cytochrome P450 enzyme system and is known that it has high toxic effects on different cells. Mesenchymal stem cells (MSCs) have recently gained importance since their potential to be used in cellular therapy and tissue regeneration. In some clinical cases, MSCs are transferred into the patient after the organ transplantations in order to support the treatment. Because of their immunomodulatory actions and assistance to the regeneration, popularity of MSCs have been increasing recently. However, since immunosuppressive agents have a potential cytotoxic and apoptotic effect on MSCs, researches have attempted to use it as a combination with an agent that alleviates these effects. Oxytocin (OT) is primarily acting as a neuromodulator in humans and is a peptide hormone secreted by the pituitary gland of the neurohypophysis. OT has such effects on cells as to confer resistance against oxidative stress on cells and to increase the proliferation and help regeneration. Studies on the active substance of FK506 were aimed to investigate the cytotoxic effects on human adipose tissue derived MSCs. The purpose of this study was to determine the cytotoxic, apoptotic and morphological effects of FK506, an immunosuppressive agent, on adipose tissue - derived MSC (ADMSC) which has the potential to be used for immune suppression. In addition, it was aimed to determine whether the agent could reduce the cytotoxic, apoptotic, and morphological effects on ADMSCs when used in combination with OT. For this purpose, the cytotoxic effects of the FK506 and OT on ADMSCs were determined by time and dose dependent manner by the WST-1 test. Isobologram analysis was evaluated using the WST-1 test according to IC₅₀ values of FK506 and OT. The apoptotic effects of the agents on the ADMSCs were determined by the Annexin V method. Immunofluorescence staining was performed to determine morphological changes. Changes in the levels of oxidative stress markers were measured by colorimetric and flourometric methods using lipid peroxidation, superoxide dismutase activity, catalase activity and glutathione peroxidase assays. The IC₅₀ values of FK506 and OT on ADMSCs were calculated as 17.44μM and 13.43μM, respectively.FK506 and OT were found to have antagonistic activity on ADMSCs (CI value of the combination was 1.24). The effects of the agents individually and in combination on the levels of apoptosis and oxidative stress markers have been evaluated. When the results obtained from the study are evaluated, the adipose- tissue derived mesenchymal stem cells used with takrolimus and oxytocin combination have a potential for novel treatment approaches.

Dose dependent effect of resveratrol in preventing cisplatin-induced ovarian damage in rats: An experimental study

This study aimed to evaluate the effect of resveratrol in preventing cisplatin (CP) induced ovarian damage in rats. Twenty-eight female Wistar albino rats were separated into four groups. No medication was given to group 1. Over the 21-day study period, low-dose resveratrol was given to group 2, high-dose resveratrol was given to group 3, and saline was administered to group 4. On the 15th day of medication, all groups except for group 1 were treated with a single dose of CP. Serum levels of anti-Mullerian hormone (AMH) were tested at baseline and on the 15th and 21st days. All rats underwent oophorectomy one week after CP application. Primordial, primary, secondary, and tertiary follicles were counted microscopically. No significant difference was observed among the groups in mean AMH levels according to follow-up time. The numbers of primary and primordial follicles were statistically significantly higher in group 2 than in group 4 (p<0.05). The number of tertiary follicles was statistically significantly higher in group 1 than in groups 3 and 4 (p<0.05), but it was not statistically significantly different than in group 2. Resveratrol, particularly at low-doses, can prevent CP induced ovarian damage by maintaining the numbers of primordial and primary follicles. Further studies are needed to study the effect of resveratrol on human ovaries.

A putative role for anti-Müllerian hormone (AMH) in optimising ovarian reserve expenditure

The mammalian ovary has a finite supply of oocytes, which are contained within primordial follicles where they are arrested in a dormant state. The number of primordial follicles in the ovary at puberty is highly variable between females of the same species. Females that enter puberty with a small ovarian reserve are at risk of a shorter reproductive lifespan, as their ovarian reserve is expected to be depleted faster. One of the roles of anti-Müllerian hormone (AMH) is to inhibit primordial follicle activation, which slows the rate at which the ovarian reserve is depleted. A simple interpretation is that the function of AMH is to conserve ovarian reserve. However, the females with the lowest ovarian reserve and the greatest risk of early reserve depletion have the lowest levels of AMH. In contrast, AMH apparently strongly inhibits primordial follicle activation in females with ample ovarian reserve, for reasons that remain unexplained. The rate of primordial follicle activation determines the size of the developing follicle pool, which in turn, determines how many oocytes are available to be selected for ovulation. This review discusses the evidence that AMH regulates the size of the developing follicle pool by altering the rate of primordial follicle activation in a context-dependent manner. The expression patterns of AMH across life are also consistent with changing requirements for primordial follicle activation in the ageing ovary. A potential role of AMH in the fertility of ageing females is proposed herein.

Hydrogen-rich Water Exerting a Protective Effect on Ovarian Reserve Function in a Mouse Model of Immune Premature Ovarian Failure Induced by Zona Pellucida 3

Background:

Premature ovarian failure (POF) is a disease that affects female fertility but has few effective treatments. Ovarian reserve function plays an important role in female fertility. Recent studies have reported that hydrogen can protect male fertility. Therefore, we explored the potential protective effect of hydrogen-rich water on ovarian reserve function through a mouse immune POF model.

Methods:

To set up immune POF model, fifty female BALB/c mice were randomly divided into four groups: Control (mice consumed normal water, n = 10), hydrogen (mice consumed hydrogen-rich water, n = 10), model (mice were immunized with zona pellucida glycoprotein 3 [ZP3] and consumed normal water, n = 15), and model-hydrogen (mice were immunized with ZP3 and consumed hydrogen-rich water, n = 15) groups. After 5 weeks, mice were sacrificed. Serum anti-Müllerian hormone (AMH) levels, granulosa cell (GC) apoptotic index (AI), B-cell leukemia/lymphoma 2 (Bcl-2), and BCL2-associated X protein (Bax) expression were examined. Analyses were performed using SPSS 17.0 (SPSS Inc., Chicago, IL, USA) software.

Results:

Immune POF model, model group exhibited markedly reduced serum AMH levels compared with those of the control group (5.41 ± 0.91 ng/ml vs. 16.23 ± 1.97 ng/ml, P = 0.033) and the hydrogen group (19.65 ± 7.82 ng/ml, P = 0.006). The model-hydrogen group displayed significantly higher AMH concentrations compared with that of the model group (15.03 ± 2.75 ng/ml vs. 5.41 ± 0.91 ng/ml, P = 0.021). The GC AI was significantly higher in the model group (21.30 ± 1.74%) than those in the control (7.06 ± 0.27%), hydrogen (5.17 ± 0.41%), and model-hydrogen groups (11.24 ± 0.58%) (all P < 0.001). The GC AI was significantly higher in the model-hydrogen group compared with that of the hydrogen group (11.24 ± 0.58% vs. 5.17 ± 0.41%, P = 0.021). Compared with those of the model group, ovarian tissue Bcl-2 levels increased (2.18 ± 0.30 vs. 3.01 ± 0.33, P = 0.045) and the Bax/Bcl-2 ratio decreased in the model-hydrogen group.

Conclusions:

Hydrogen-rich water may improve serum AMH levels and reduce ovarian GC apoptosis in a mouse immune POF model induced by ZP3.