Dehydroepiandrosterone and metformin modulate progesterone-induced blocking factor (PIBF), cyclooxygenase 2 (COX2) and cytokines in early pregnant mice

Investigation of the Effect of Seminal Plasma Exosomes from the Normal and Oligoasthenoteratospermic Males in the Implantation Process

Background

Seminal plasma exosomes are now recognized to play a complex role in the regulation of the female reproductive system infertility. The objective of this study was to assess the effect of exosomes derived from the sperm of men with oligoasthenoteratozoospermia on endometrial implantation-related genes.

Methods

To isolate the exosomes, we employed an ultracentrifugation method on samples derived from 10 fertile men with normal sperm parameters and 10 men with oligoasthenoteratozoospermia. The size distribution and ultrastructure of the exosomes were then characterized using transmission electron microscopy and dynamic light scattering. We detected an exosome marker using western blot analysis and confirmed the cytoplasmic localization of the exosomes by incubating them with DiI dye and visualizing them using fluorescence microscopy. After 6 hours of in vitro treatment of endometrial epithelial cells with 100 µg/ml seminal exosome, the endometrial receptivity genes were examined using qRT-PCR. To perform data analysis and quantification, we utilized Image J and Prism software. P< 0.05 were considered statistically significant.

Results

After 6 hours of treatment, the mRNA levels of MUC1, LIF, G-CSF, CX3CL1, and VEGF were significantly downregulated in the endometrial epithelial cells treated with oligoasthenoteratozoospermia exosomes compared to the normal group. Although changes were observed in the mean mRNA levels of IL8 and TGF-β genes in the oligoasthenoteratozoospermia group compared to the normal group, these differences did not reach statistical significance (p > 0.05).

Conclusions

Oligoasthenoteratozoospermia exosomes have a distinct effect on endometrial receptivity compared to normal exosomes, leading to reduced expression of implantation-related genes.

Composition and effects of seminal plasma in the female reproductive tracts on implantation of human embryos

The function of seminal plasma involves acting as a transport medium for sperm and as a means of communication between the reproductive tissues of the male and female. It is also a vital factor to prime the reproductive tracts of the female for optimal pregnancy. When the reproductive tract of the female is exposed to seminal plasma, serious alterations take place, enhancing pathogen and debris clearance observed in the uterus throughout mating. It is also capable of supporting embryo growth, promoting the receptivity of the uterus, and establishing tolerance to the semi-allogenic embryo. Moreover, seminal plasma is capable of regulating the functions of several female reproductive organs and providing an ideal condition for effective embryo implantation and pregnancy. It is believed that the health state of the offspring is affected by exposure to seminal plasma. For the treatment of infertility, assisted reproductive technologies have been extensively employed. The application of seminal plasma as a therapeutic approach to enhance the development of embryo competency and rate of implantation, receptivity of endometrium, and establishment of maternal immune tolerance in cycles of ART appears possible. Herein, current knowledge on the composition of seminal plasma and the physiological roles it possesses on various parts of the female reproductive tract are summarized. Moreover, the role of seminal plasma in the development of embryos, implantation, and the following fetal growth and survival have been reviewed in this article.

Influence of Vitamin D on the Vasoactive Effect of Estradiol in a Rat Model of Polycystic Ovary Syndrome

We examined the vasoactive effect of estradiol in a rat model of early PCOS and the influence of vitamin D deficiency (VDD). We created a model of chronic hyperandrogenism and VDD in adolescent female Wistar rats (N = 46) with four experimental groups: vitamin D supplemented (T-D+), VDD (T-D-), hyperandrogenic and vitamin D supplemented (T+D+), and hyperandrogenic and VDD (T+D-). T+ groups received an 8-week-long transdermal Androgel treatment, D-animals were on vitamin D-reduced diet and D+ rats were supplemented orally with vitamin D3. Estrogen-induced vasorelaxation of thoracic aorta segments were measured with a wire myograph system with or without the inhibition of endothelial nitric oxide synthase (eNOS) or cyclooxygenase-2 (COX-2). The distribution of estrogen receptor (ER), eNOS and COX-2 in the aortic wall was assessed by immunohistochemistry. VDD aortas showed significantly lower estradiol-induced relaxation independently of androgenic status that was further decreased by COX-2 inhibition. COX-2 inhibition failed to alter vessel function in D+ rats. Inhibition of eNOS abolished the estradiol-induced relaxation in all groups. Changes in vascular function in VDD were accompanied by significantly decreased ER and eNOS staining. Short-term chronic hyperandrogenism failed to, but VDD induced vascular dysfunction, compromised estrogen-dependent vasodilatation and changes in ER and eNOS immunostaining.

Metformin suppresses breast cancer growth via inhibition of cyclooxygenase-2

Pre-clinical and on-going trials have indicated the advantage of using metformin as an anticancer drug alone or in combination with other chemotherapeutics for the treatment of patients with breast cancer. However, the mechanisms by which metformin attenuates tumorigenesis remain to be further elucidated. The present study investigated the anticancer effects of metformin in breast cancer and identified potential molecular targets of metformin using western blotting and immunohistochemical analysis. Metformin significantly decreased tumor cell proliferation in vitro and suppressed tumor growth in vivo. Moreover, it induced the activation of AMP-induced protein kinase and suppression of phosphorylated-eukaryotic translation initiation factor 4E-binding protein 1 (p-4E-BP1), a downstream effector of the mTOR signaling pathway, and decreased cyclin D1 levels in in vitro and in vivo experimental models. Additionally, metformin inhibited cyclooxygenase (COX)-2 expression. Clinically, high expression levels of COX-2 and p-4E-BP1 in tissues of patients with breast cancer were significantly associated with enhanced lymphatic metastasis and distant metastasis. Thus, the current data suggested that metformin may have potential value as a synergistic therapy targeting both the COX-2 and mTOR signaling pathways.

Inflammation and reproductive function in women with polycystic ovary syndrome†

Polycystic ovary syndrome (PCOS) is one of the most frequent endocrinopathies, affecting 5-10% of women of reproductive age, and is characterized by the presence of ovarian cysts, oligo, or anovulation, and clinical or biochemical hyperandrogenism. Metabolic abnormalities such as hyperinsulinemia, insulin resistance, cardiovascular complications, dyslipidemia, and obesity are frequently present in PCOS women. Several key pathogenic pathways overlap between these metabolic abnormalities, notably chronic inflammation. The observation that this mechanism was shared led to the hypothesis that a chronic inflammatory state could contribute to the pathogenesis of PCOS. Moreover, while physiological inflammation is an essential feature of reproductive events such as ovulation, menstruation, implantation, and labor at term, the establishment of chronic inflammation may be a pivotal feature of the observed reproductive dysfunctions in PCOS women. Taken together, the present work aims to review the available evidence about inflammatory mediators and related mechanisms in women with PCOS, with an emphasis on reproductive function.

Epigenetic Marks in Polycystic Ovary Syndrome

Polycystic Ovary Syndrome (PCOS) is a common endocrine and metabolic disorder that affects women in their reproductive age. Recent studies have shown that genes have an important role in the etiology of PCOS. However, the precise way in which these genes are transcriptionally and post-transcriptionally regulated is poorly understood. The aim of the present review is to provide updated information on miRNAs and DNA methylation as epigenetic marks of PCOS. The data presented here allow concluding that both microRNAs and DNA methylation can be considered as possible useful biomarkers when choosing the treatment for a specific PCOS phenotype and thus represent two important tools for the diagnosis and treatment of PCOS patients.

Improvement in the epigenetic modification and development competence in PCOS mice oocytes by hydro-alcoholic extract of Nigella sativa during in-vitro maturation: An experimental study

Background

Nigella Sativa (NS) and its active component, thymoquinone, have beneficial protective effects on experimental animal models of polycystic ovary syndrome (PCOS) and different human diseases.

Objective

The present study aimed to investigate the effects of NS hydro-alcoholic extract (NSE) on the oocyte quality of PCOS mice during in vitro maturation.

Materials and Methods

For induction of PCOS, 40 prepubertal 21-days old female B6D2F1 mice (18-22 g body weight) received subcutaneous dehydroepiandrosterone daily. After validation of the model, germinal vesicle-stage oocytes of superovulated mice were collected and placed in the culture medium containing different concentrations (0, 1, 50, and 100 μg/ml) of NSE. For the measurement of developmental competency, some mature oocytes were fertilized with epididymal spermatozoa. Other mature oocytes were assessed for oxidative stress. Also, some mRNA expression levels involved in oocyte maturation and epigenetic modification were evaluated.

Results

The 50 μg/ml NSE treated group showed significantly higher r ates o f maturation, f ertilization, and blastocyst formation in comparison with both control and PCOS groups. A high level of glutathione concentration and glutathione peroxidase mRNA expression, besides a low level of reactive oxygen species content all, were observed in oocytes treated with 50 μg/ml NSE, indicating the modification of oxidative statue. Furthermore, the oocytes in the 50 μg/ml-treated group showed an upregulation of mRNA expression in epigenetic-related genes (Dnmt1 and Hdac1) and maternally derived genes (Mapk and Cdk1), correspondingly downregulation of cyclooxygenase2 mRNA expression, in comparison to other groups.

Conclusion

The results of this study indicated that 50 μg/ml NSE improves oocyte maturation, oxidative statues and epigenetic modifications. These may be the all reasons for the developmental competency in the control and PCOS mice oocytes.

Metformin from mother to unborn child - Are there unwarranted effects?

For more than 40 years, metformin has been used before and during pregnancy. However, it is important to note that metformin can cross the placenta and circulate in the developing foetus. Recent studies reported that the concentration of metformin in foetal cord blood ranges from half to nearly the same concentration as in the maternal plasma. Since metformin has anti-cell growth and pro-apoptotic effects, there are persistent concerns over the use of metformin in early pregnancy. Current human studies are limited by sample size, lack of controls or, short follow-up durations. In this review, we examine the settings in which metformin can be passed on from mother to child during pregnancy and address the current controversies relating to the cellular and molecular mechanisms of metformin. Our efforts highlight the need for more data on the effects of metformin on general offspring health as well as further scrutiny into foetal development upon exposure to metformin.

A short course of metformin does not reduce OHSS in a GnRH antagonist cycle for women with PCOS undergoing IVF: a randomised placebo-controlled trial

STUDY QUESTION

Does 'metformin' reduce the incidence of ovarian hyperstimulation syndrome (OHSS) for women with polycystic ovary syndrome (PCOS) undergoing a GnRH antagonist assisted conception treatment cycle?

SUMMARY ANSWER

A short course of metformin does not reduce the incidence of OHSS for women with PCOS undergoing a GnRH antagonist treatment cycle.

WHAT IS KNOWN ALREADY

Metformin does reduce the incidence of OHSS in a GnRH-agonist treatment cycle.

STUDY DESIGN, SIZE, DURATION

A randomised placebo-controlled trial (RCT) using metformin or placebo. Randomisation was blinded to both patient and investigator, using a random permuted blocks method with a 50:50 allocation ratio. The study was completed over 5 years (2009-2014) with 153 randomised patients. A sample size calculation based on the incidence of OHSS was completed prospectively suggesting a minimum of 146 recruits was required for the trial with a power of 80% and a type 1 error of 0.05.

PARTICIPANTS/MATERIALS, SETTING, METHODS

All patients met the Rotterdam criteria for PCOS and were treated with a standard GnRH antagonist IVF/ICSI treatment cycle in a tertiary infertility clinic. The study medication was started prior to stimulation and continued to oocyte retrieval. Of the 153 patients, 77 received metformin and 76 placebo.

MAIN RESULTS AND THE ROLE OF CHANCE

There was no reduction in the incidence of moderate-severe OHSS (Placebo (PLA) 12.2%, metformin (MET) = 16%, 95% CI -0.08-0.16, P = 0.66). There was no difference in total gonadotrophin dose (PLA = 1200, MET = 1200, 95% CI -118.67-118.67, P = 0.75), oocytes retrieved (PLA = 15, MET = 14, 95% CI -2.37-4.37, P = 0.66) or fertilisation rate (PLA = 60.7%, MET = 53.3%, 95% CI -0.96-14.94, P = 0.07). However, using metformin resulted in a reduced clinical pregnancy rate (CPR) per cycle started (PLA = 48.7%, MET = 28.6%, 95% CI 0.04-0.35, P = 0.02) and live birth rate (PLA = 51.6%, MET = 27.6%, 95% CI 0.05-0.40, P = 0.02). Furthermore, when ethnicity was taken into account there was a significant reduction in pregnancy outcome for the South Asian population irrespective of metformin or placebo use (CPR per cycle started, White Caucasian = 44.4%, South Asian = 19.4%; 95% CI 0.06-0.39, P = 0.01).

LIMITATIONS, REASONS FOR CAUTION

This study was only undertaken on an infertility population with PCOS with a limited duration of study medication use.

WIDER IMPLICATIONS OF THE FINDINGS

This is the first adequately powered RCT to assess the impact of metformin on OHSS in a high-risk group (women with PCOS) undergoing a GnRH antagonist cycle. It does not support the empirical prescribing of metformin as an adjunct to a GnRH antagonist treatment cycle.

STUDY FUNDING/COMPETING INTERESTS

None.

TRIAL REGISTRATION NUMBER

EudraCT number 2009-010952-81.

TRIAL REGISTRATION DATE

21 September 2009.

DATE OF FIRST PATIENT'S ENROLMENT

30 October 2009.

Metformin represses bladder cancer progression by inhibiting stem cell repopulation via COX2/PGE2/STAT3 axis

Cancer stem cells (CSCs) are a sub-population of tumor cells playing essential roles in initiation, differentiation, recurrence, metastasis and development of drug resistance of various cancers, including bladder cancer. Although multiple lines of evidence suggest that metformin is capable of repressing CSC repopulation in different cancers, the effect of metformin on bladder cancer CSCs remains largely unknown. Using the N-methyl-N-nitrosourea (MNU)-induced rat orthotropic bladder cancer model, we demonstrated that metformin is capable of repressing bladder cancer progression from both mild to moderate/severe dysplasia lesions and from carcinoma in situ (CIS) to invasive lesions. Metformin also can arrest bladder cancer cells in G1/S phases, which subsequently leads to apoptosis. And also metformin represses bladder cancer CSC repopulation evidenced by reducing cytokeratin 14 (CK14+) and octamer-binding transcription factor 3/4 (OCT3/4+) cells in both animal and cellular models. More importantly, we found that metformin exerts these anticancer effects by inhibiting COX2, subsequently PGE2 as well as the activation of STAT3. In conclusion, we are the first to systemically demonstrate in both animal and cell models that metformin inhibits bladder cancer progression by inhibiting stem cell repopulation through the COX2/PGE2/STAT3 axis.

Effects of Angiotensin-Converting Enzyme Inhibitor Derived from Tropaeolum majus L. in Rat Preimplantation Embryos: Evidence for the Dehydroepiandrosterone and Estradiol Role

Although several studies have shown the inhibitory effects of Tropaeolum majus extracts (HETM) on angiotensin-converting enzyme (ACE) activity, no studies have been carried out during the beginning of pregnancy, when humoral and hormonal imbalance may affect zygote and early embryo transport. This study investigates whether HETM can affect embryonic development when administered during the one-cell-blastocyst period. Pregnant Wistar rats received orally the HETM (3, 30, and 300 mg/kg/day) from the 1st to the 7th gestational day. Rats were killed on the 8th day of pregnancy and the following parameters were evaluated: clinical symptoms of toxicity (including organ weights), number of corpora lutea, implants per group, preimplantation losses ratio, and the serum levels of dehydroepiandrosterone (DHEA), estradiol, and progesterone. No clinical symptoms of maternal toxicity were evidenced. On the 8th day of pregnancy, the levels of DHEA and estradiol were increased and significant preimplantation losses were observed at all doses used. The present study reveals that the HETM can raise levels of DHEA and estradiol and induce difficulty in the embryo implantation in the early stages of pregnancy. The data contributes significantly to the safety aspects of using this natural product when trying to get pregnant or during pregnancy.

Effects of vitamin E on reproductive protection in pregnant mice infected with pseudorabies virus (PRV) via regulating expression of Toll-like receptors (TLRs) and cytokine balance

Vitamin E supplement and pseudorabies virus (PRV) infection have a reciprocal role in influencing the maternal immune response, a key determinant of the success or failure of pregnancy. However, it remains unknown whether vitamin E supplement provides protection against PRV-induced failure of pregnancy. This study was therefore conducted to investigate the effect of dietary vitamin E level (0, 75, 375, 750 and 1,500 mg/kg) on the reproduction performance, immunity and expression of Toll-like receptors (TLRs) of PRV-challenged mice. The mortality and abortion rate of PRV-challenged mice decreased with the increase in vitamin E consumption. Overall, PBS-injected mice had a higher live embryo number and live litter size than PRV-challenged mice. Both live embryo number and live litter size of PRV-challenged mice increased with increasing vitamin E levels. Vitamin E supplement resulted in decreased concentration of serum IL-2 and IFN-γ, but increased concentration of serum IL-10. The concentration of serum IgG, IgA and IgM increased with increasing vitamin E levels. In the uterine and embryo mRNA abundance of TLR3, TLR7 and TLR9 was higher in PRV-challenged mice than that in PBS-injected mice fed on the same dosage of vitamin E. The mRNA abundance of embryonic TLR3, TLR7 and TLR9 in PRV-challenged mice decreased with increasing vitamin E levels. Collectively, vitamin E supplement may improve reproductive performance of PRV-challenged mice by attenuating PRV-induced negative effects on the cytokine profile, immunoglobulin synthesis and TLR expression.

Report of the international symposium: polycystic ovary syndrome: first Latin-American consensus

During the last years, numerous consensuses have been held in different countries in order to review the data concerning diagnosis and treatment and their relationship with the ethnic origin, social status and lifestyle of women with Polycystic Ovary Syndrome (PCOS). This study describes the conclusions concerning diagnostic criteria and the appropriate treatment of women with PCOS reached during the International Symposium Polycystic Ovary Syndrome, First Latin-American Consensus held in Buenos Aires, Argentina on 4th and 5th May 2009 to be applied in South American.

Dehydroepiandrosterone to induce murine models for the study of polycystic ovary syndrome

During the last decade a battery of animal models used for the study of polycystic ovary syndrome (PCOS) have allowed a focus on different aspects of the pathology. Since dehydroepiandrosterone (DHEA) was found to be one of the most abundant circulating androgens in women with PCOS, a rodent model showing the salient features found in women with PCOS was developed by the injection of DHEA. Although insulin-sensitizing agents, such as biguanides, are clinically used in the treatment of diabetes and PCOS, the complete understanding of their mechanisms of action remains unknown. The present review discusses the molecular mechanisms involved in the development of PCOS by using the DHEA-PCOS murine model and analyzes the role of the biguanide metformin as treatment.

PIBF: the double edged sword. Pregnancy and tumor

PROBLEM

The role of progesterone-dependent immunomodulation in the maintenance of normal pregnancy.

METHODS

In vitro and in vivo data on the effect that progesterone and its mediator progesterone-induced blocking factor (PIBF) exert on the immune functions of pregnant women are reviewed, together with clinical findings.

RESULTS

Activated pregnancy lymphocytes express progesterone receptors, which enable progesterone to induce a protein called PIBF. PIBF increases Th2 type cytokine production by signaling via a novel type of IL-4 receptor and activating the Jak/STAT pathway. PIBF inhibits phosholipase A2, thus reduces prostaglandin synthesis. PIBF inhibits perforin release in human decidual lymphocytes and reduces the deleterious effect of high NK activity on murine pregnancy. PIBF production is a characteristic feature of normal human pregnancy, and its concentration is reduced in threatened pregnancies. PIBF mRNA and protein are expressed in a variety of malignant tumors. Inhibition of PIBF synthesis increases survival rates of leukemic mice.

CONCLUSION

Progesterone-induced blocking factor is produced by pregnancy lymphocytes and also by malignant tumors. The PIBF-induced Th2-dominant immune response is favorable during pregnancy but might facilitate tumor growth by suppressing local antitumor immune responses.

Effect of DHEA and metformin on corpus luteum in mice

We evaluated the effect of hyperandrogenism in ovaries with functional and regressing corpora lutea (CL) and the action of metformin in preventing these possible alterations using a mouse model. To obtain a CL functional for 9+/-1 days, immature female mice of the BALB/c strain were injected i.p. with 10 IU/mouse of pregnant mare's serum gonadotropin (PMSG). DHEA (60 mg/kg body weight s.c., 24 and 48 h prior to kill) decreased both serum progesterone (P) and estradiol (E(2)) levels and increased the activity of superoxide dismutase (SOD) from ovaries with functional CL (on day 5 after PMSG). It increased P and E(2) and the activities of SOD and catalase (CAT) and decreased lipoperoxidation of ovaries with regressing CL (on day 9 after PMSG). Treatment with DHEA did not affect the production of prostaglandin F(2alpha) (PGF(2alpha)) or PGE by ovaries with functional CL, whereas DHEA decreased PGF(2alpha) and increased PGE production by ovaries with regressing CL. Metformin (50 mg/kg body weight, orally) given together with DHEA restored E(2) levels from mice with ovaries with functional CL and serum P, PGF(2alpha) and PGE levels, and oxidative balance in mice with ovaries with regressing CL. Metformin alone was able to modulate serum P and E(2) levels, lipoperoxidation, SOD and CAT, and the 5,5-dimethyl-1-pyrroline N-oxide/(*)OH signal. These findings suggest that hyperandrogenism is able to induce or to rescue CL from luteolysis and metformin treatment is able to prevent these effects.

The effects of metformin on uterine tissue of hyperandrogenized BALB/c mice

The present study investigated the role of the N, N'-dimethylbiguanide metformin (50 mg/kg body weight in 0.05 ml water, given orally with a canulla) in preventing the adverse effects generated by hyperandrogenism on uterine function. Daily injection of dehydroepiandrosterone (DHEA: 6 mg/100 g body weight in 0.1 ml oil) for 20 consecutive days induces polycystic ovaries in BALB/c mice. In this model we found that DHEA produced alterations on uterine histology closely related to the development of pre-cancerous structures concomitantly with increased incidence of uterine apoptosis. The injection of DHEA induced a pro-inflammatory status since uterine prostaglandin (PG) F2 alpha levels and cyclooxygenase 2 were increased although PGE levels were decreased. Furthermore, DHEA promoted a pro-oxidant status since it increased nitric oxide synthase (NOS) activity and decreased superoxide dismutase and catalase activities and the antioxidant metabolite glutathione levels. DHEA also regulated the percentages of CD4+ and CD8+ T lymphocyte that infiltrate uterine tissue. When metformin was administered together with DHEA uterine histology and apoptosis did not differ when compared with controls. Therefore, metformin prevented the pro-inflammatory and pro-oxidative status generated by DHEA and restores the ratios of CD4+ and CD8+ T cells to those observed in controls. We conclude that metformin is able to restore either directly or indirectly uterine function by preventing some inflammatory and oxidative alterations produced by hyperandrogenism.