Resveratrol promotes in vitro activation of ovine primordial follicles by reducing DNA damage and enhancing granulosa cell proliferation via phosphatidylinositol 3-kinase pathway

How phytochemicals influence reproductive outcomes in women receiving assisted reproductive techniques: a systematic review

CONTEXT

Over the past few years, there has been an increasing amount of scholarly literature suggesting a connection between the nutritional status of pregnant mothers and early fetal development, as well as the long-term health consequences of their offspring. Multiple studies have documented that alterations in dietary patterns prior to conception have the potential to affect the initial stages of embryonic development.

OBJECTIVES

The aim of this study was to perform a comprehensive review of the research pertaining to the correlation between phytochemicals ( specifically, polyphenols, carotenoids and phytoestrogens) and assisted reproductive technology (ART).

DATA SOURCES

PubMed, Scopus, Web of Science, and Clinical Trials databases were searched from January 1978 to March 2023.

STUDY SELECTION

This study comprised observational, randomized controlled, and cohort studies that examined the effects of phytochemicals on ART results. The study's outcomes encompass live birth rate, clinical pregnancy, and ongoing pregnancy.

DATA EXTRACTION

The assessment of study quality was conducted by 2 researchers, independently, using the Quality Criteria Checklist for Primary Research.

RESULTS

A total of 13 studies were included, of which there were 5 randomized controlled studies, 1 nonrandomized controlled study, 6 prospective cohort studies, and 1 retrospective cohort study.

CONCLUSION

This research focused on investigating the impact of phytochemicals on ART and has highlighted a dearth of articles addressing that topic. Collaboration among patients, physicians, and nutritionists is crucial for doing novel research.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO registration no. CRD42023426332.

Resveratrol Promotes Proliferation, Antioxidant Properties, and Progesterone Production in Yak (Bos grunniens) Granulosa Cells

Resveratrol (RES) is a class of natural polyphenolic compounds known for its strong anti-apoptotic and antioxidant properties. Granulosa cells (GCs) are one of the important components of ovarian follicles and play crucial roles in follicular development of follicles in the ovary. Here, we explored the effects of RES on the proliferation and functions of yak GCs. Firstly, we evaluated the effect of RES dose and time in culture on the viability of GCs, and then the optimum treatment protocol (10 μM RES, 36 h) was selected to analyze the effects of RES on the proliferation, cell cycle, apoptosis, malondialdehyde (MDA), glutathione (GSH), reactive oxygen species (ROS) accumulation, lipid droplet content, ATP production, and steroidogenesis of GCs, as well as the expression of related genes. The results show that RES treatment significantly (1) increased cell viability and proliferation and inhibited cell apoptosis by upregulating BCL-2 and SIRT1 genes and downregulating BAX, CASP3, P53, and KU70 genes; (2) increased the proportion of GCs in the S phase and upregulated CCND1, PCNA, CDK4, and CDK5 genes; (3) reduced ROS accumulation and MDA content and increased GSH content, as well as upregulating the relative expression levels of CAT, SOD2, and GPX1 genes; (4) decreased lipid droplet content and increased ATP production; (5) promoted progesterone (P4) secretion and the expression of P4 synthesis-related genes (StAR, HSD3B1, and CYP11A1); and (6) inhibited E2 secretion and CYP19A1 expression. These findings suggest that RES at 10 μM increases the proliferation and antioxidant properties, inhibits apoptosis, and promotes ATP production, lipid droplet consumption, and P4 secretion of yak GCs.

Impact of antioxidant supplementation during in vitro culture of ovarian preantral follicles: A review

The in vitro culture systems of ovarian preantral follicles have been developed for studying follicular and oocyte growth, for future use of immature oocytes as sources of fertilizable oocytes and for screening ovarian toxic substances. One of the key limitations of the in vitro culture of preantral follicles is the oxidative stress by accumulation of reactive oxygen species (ROS), which can impair follicular development and oocyte quality. Several factors are associated with oxidative stress in vitro, which implies the need for a rigorous control of the conditions as well as addition of antioxidant agents to the culture medium. Antioxidant supplementation can minimize or eliminate the damage caused by ROS, supporting follicular survival and development and producing mature oocytes competent for fertilization. This review focuses on the use of antioxidants and their role in preventing follicular damage caused by oxidative stress in the in vitro culture of preantral follicles.

Resveratrol alleviates doxorubicin-induced damage in mice ovary

While oocytes and embryos cryopreservation can favor some patients with cancer-induced infertility to achieve pregnancy, the development of effective therapeutic strategies to preserve ovarian function during chemotherapy would be a significant advantage. The aim of the present study is to analyze whether Resveratrol treatment (Res) can preserve ovarian function from doxorubicin (Doxo)-induced gonadotoxicity using a mice model of premature ovarian failure. Res (7 and 15 mg/kg) increased the percentage of primary and antral follicles whilst decreasing the percentage of atretic follicles compared to Doxo alone. Res preserved the number of primordial follicles compared with those in the Doxo group but they did not change from those in the control group. Res treatment increased the number of AMH positive follicles compared to Doxo alone. Res increased proliferation index in follicular cells and reduced the DNA damage and apoptosis in preantral and early antral follicles compared to Doxo alone. Additionally, Doxo administration caused a severe endothelial damage and affected microvasculature stability in the ovary. However, Res was able to increase the recruitment of pericytes and smooth muscle cells in the Doxo-treated group. We also found that Res increased the expression of VEGF compared to Doxo alone. By H&E staining, Doxo-treated mice demonstrated endometrial alterations compared to controls, affecting both epithelial and stromal compartments. Nonetheless, Res restored the architecture of uterine tissue. Moreover, we also showed that Res administration is able to maintain antioxidant defenses through the increase of SOD expression in the Doxo-induced POF model. In conclusion, Res administration prior to and during Doxo treatment might serve as a noninvasive and low-cost protocol to preserve ovarian function in female cancer survivors.

Thermoprotective molecules: Effect of insulin-like growth factor type I (IGF-1) in cattle oocytes exposed to high temperatures

The adverse effects of heat stress (HS) on the welfare and productivity of cattle are the result of the associated hyperthermia and the physiological and behavioral mechanisms performed by the animal to regulate body temperature. The negative effects of HS on in vitro oocyte maturation and in vitro bovine embryo production have been reported; being one of the major concerns due to economic and productive losses, and several mechanisms have been implemented to reduce its impact. These mechanisms include supplementation of the medium with hormones, adjuvants, identification of protective genes, among others. This review aims to explore the cellular and molecular mechanisms of insulin-like growth factor-1 (IGF-1) during in vitro and in vivo maturation of bovine oocytes and its thermoprotective effect under HS. Although the supplementation of the culture medium during oocyte maturation with IGF-1 has been implemented during the last years, there are still controversial results, however, supplementation with low concentration showed a positive effect on maturation and thermoprotection of oocytes exposed to higher temperatures. Additionally, IGF-1 is involved in multiple cellular pathways, and it may regulate cell apoptosis in cases of HS and protect oocyte competence under in vitro conditions.

Extremely Active Nano-formulation of Resveratrol (XAR™) attenuates and reverses chemotherapy-induced damage in mice ovaries and testes

BACKGROUND

Fertility preservation and restoration in cancer patients/survivors is the need of present times when increased numbers of patients get cured of cancer but face infertility as a serious side effect. Resveratrol has beneficial effects on chemoablated ovaries and testes in mice but has failed to enter the clinics because of extremely poor bioavailability. The present study was undertaken to evaluate the protective and curative effects of Extremely active Resveratrol (XAR™)- a nano-formulation of resveratrol with significantly improved bioavailability- on mouse ovary and testis after chemotherapy. Effects of XAR™ and FSH were compared on stimulation of follicle growth in adult mice ovaries. XAR™ (25 mg/kg) was administered for two days prior to chemotherapy to study the protective effects on the mouse gonads. XAR™ was also administered for 14 days post chemoablation to study the regenerative effects. Besides effect on numbers of primordial and growing follicles and spermatogenesis, the effect of XAR™ was also evaluated on the transcripts specific for ovarian/testicular stem/progenitor/germ cells, their proliferation, differentiation, meiosis, and the antioxidant indices.

RESULTS

Similar to FSH, XAR™ increased the numbers of primordial follicles (PF) as well as growing follicles. It protected the gonads from the adverse effects of chemotherapy and showed the ability to regenerate non-functional, chemoablated gonads. Besides stimulating follicle growth in adult ovaries similar to FSH, XAR™ also protected the testes from the adverse effects of chemotherapy and improved spermatogenesis. This was accompanied by improved anti-oxidant indices.

CONCLUSIONS

The results of the present study potentiate the use of XAR™ in pilot clinical studies to protect gonadal function during oncotherapy and also regenerate non-functional gonads in cancer survivors by improving antioxidant indices and stem cell-based tissue regeneration.

The Utilization of Physiologically Active Molecular Components of Grape Seeds and Grape Marc

Nutritional interventions may highly contribute to the maintenance or restoration of human health. Grapes (Vitis vinifera) are one of the oldest known beneficial nutritional components of the human diet. Their high polyphenol content has been proven to enhance human health beyond doubt in statistics-based public health studies, especially in the prevention of cardiovascular disease and cancer. The current review concentrates on presenting and classifying polyphenol bioactive molecules (resveratrol, quercetin, catechin/epicatechin, etc.) available in high quantities in Vitis vinifera grapes or their byproducts. The molecular pathways and cellular signaling cascades involved in the effects of these polyphenol molecules are also presented in this review, which summarizes currently available in vitro and in vivo experimental literature data on their biological activities mostly in easily accessible tabular form. New molecules for different therapeutic purposes can also be synthesized based on existing polyphenol compound classes available in high quantities in grape, wine, and grape marc. Therefore an overview of these molecular structures is provided. Novel possibilities as dendrimer nanobioconjugates are reviewed, too. Currently available in vitro and in vivo experimental literature data on polyphenol biological activities are presented in easily accessible tabular form. The scope of the review details the antidiabetic, anticarcinogenic, antiviral, vasoprotective, and neuroprotective roles of grape-origin flavonoids. The novelty of the study lies in the description of the processing of agricultural by-products (grape seeds and skins) of industrial relevance, and the detailed description of the molecular mechanisms of action. In addition, the review of the clinical therapeutic applications of polyphenols is unique as no summary study has yet been done.

Immunolocalization of melatonin receptor type 1 in the sheep ovary and involvement of the PI3K/Akt/FOXO3a signaling pathway in the effects of melatonin on survival and in vitro activation of primordial follicles

This study characterized the expression of melatonin receptor type 1 (MT₁ ) protein in sheep ovaries, evaluated melatonin effects on primordial follicle survival and development after in vitro culture of ovarian tissue and verified the possible involvement of the phosphatidylinositol-3-kinase/protein kinase B/forkhead box O3a (PI3K/Akt/FOXO3a) pathway in the melatonin actions. Ovine ovarian fragments were cultured in α-modified minimum essential medium alone (α-MEM⁺ ) or supplemented with 100, 500, or 1000 pg/ml melatonin for 7 days. PI3K inhibition was performed through pretreatment of ovarian fragments with LY294002. Thereafter, immunohistochemistry was performed to evaluate the expression of cleaved caspase-3, Akt, phosphorylated-Akt, and phosphorylated-FOXO3a (p-FOXO3a). The immunohistochemical localization of the MT₁ receptor protein was documented in sheep preantral and antral follicles. After in vitro culture, 100 pg/ml melatonin showed higher follicular survival and activation than α-MEM⁺ and other melatonin concentrations. After PI3K inhibition, there was an increase in cleaved caspase-3-positive follicles, and a decrease in the primordial follicle activation, Akt phosphorylation, and nuclear exclusion of p-FOXO3a. In conclusion, MT₁ receptor protein is present in the sheep ovary. Furthermore, 100 pg/ml melatonin maintains survival and stimulates activation of primordial follicles through the PI3K/Akt/FOXO3a signaling pathway after in vitro culture of sheep ovarian tissue.

Resveratrol regulates the inflammation and oxidative stress of granulosa cells in PCOS via targeting TLR2

Polycystic ovary syndrome (PCOS) is featured as a common endocrine disorder in reproductive-aged women, while its pathophysiology is not fully illustrated. This study examined potential actions of resveratrol in PCOS cellular model and explored the underlying interaction between resveratrol and toll-like receptor 2 (TLR2). This study performed the bioinformatics analysis on two microarray datasets (GSE34526 and GSE138518). We found that TLR2 was one of potential hub genes that may be associated with PCOS. Further examination showed that TLR2 was highly expressed in granulosa cells from PCOS group compared with control. The in vitro studies showed that LPS intervention caused an increased expression of TLR2 and the pro-inflammatory mediators, and induced oxidative stress in the granulosa cells, which was concentration-dependently antagonized by resveratrol treatment. TLR2 silence significantly attenuated LPS-induced increase TNF-α, IL-1β, IL-6 and IL-8 expression and oxidative stress of granulosa cells. Furthermore, TLR2 overexpression promoted inflammatory response and oxidative stress in the granulosa cells, which was antagonized by resveratrol treatment. In conclusion, resveratrol could attenuate LPS-induced inflammation and oxidative stress in granulosa cells, and the underlying mechanisms may be related to the inhibitory effect of resveratrol on TLR2 expression in granulosa cells.

Successful Mestrual Regularity and Spontaneous Pregnancies with a Resveratrol-Based Multivitamin Supplement in Women with Idiopathic Premature Ovarian Insufficiency

Premature ovarian insufficiency (POI) is a clinical syndrome defined by loss of ovarian activity before the age of 40 years and is characterized by menstrual disturbance, follicle stimulating hormone (FSH) concentration above 40 IU/l and infertility. In some patients the best option is to conceive spontaneously since many treatment strategies remain unsuccessful or involve eggs donation. In this case report series, we describe the effects of a resveratrol-based multivitamin supplement containing trans-resveratrol, folic acid, vitamin B6, B12 and D, in six women with poor prognosis of pregnancy due to POI and evaluate the achievement of desired conception.

These women, aged less then 40 years, suffered from menstrual irregularities, anovulation and infertility. They all had normal karyotype, and no history of ovarian surgery, radiation exposure or chemotherapy. Blood test showed at least two values of FSH above 40 IU/l.

Four out of six patients with POI conceived after 3-6 months of a resveratrol-based multivitamin supplement, ultimately giving birth to a full-term baby. Regular menstrual cycle was restored in all patients after two to four months the start of treatment. In conclusion the treatment with a resveratrol-based supplement improved menstrual regularity and suggest a useful potential of this supplementation in some cases of POI.

In Vitro Folliculogenesis in Mammalian Models: A Computational Biology Study

In vitro folliculogenesis (ivF) has been proposed as an emerging technology to support follicle growth and oocyte development. It holds a great deal of attraction from preserving human fertility to improving animal reproductive biotechnology. Despite the mice model, where live offspring have been achieved,in medium-sized mammals, ivF has not been validated yet. Thus, the employment of a network theory approach has been proposed for interpreting the large amount of ivF information collected to date in different mammalian models in order to identify the controllers of the in vitro system. The WoS-derived data generated a scale-free network, easily navigable including 641 nodes and 2089 links. A limited number of controllers (7.2%) are responsible for network robustness by preserving it against random damage. The network nodes were stratified in a coherent biological manner on three layers: the input was composed of systemic hormones and somatic-oocyte paracrine factors; the intermediate one recognized mainly key signaling molecules such as PI3K, KL, JAK-STAT, SMAD4, and cAMP; and the output layer molecules were related to functional ivF endpoints such as the FSH receptor and steroidogenesis. Notably, the phenotypes of knock-out mice previously developed for hub.BN indirectly corroborate their biological relevance in early folliculogenesis. Finally, taking advantage of the STRING analysis approach, further controllers belonging to the metabolic axis backbone were identified, such as mTOR/FOXO, FOXO3/SIRT1, and VEGF, which have been poorly considered in ivF to date. Overall, this in silico study identifies new metabolic sensor molecules controlling ivF serving as a basis for designing innovative diagnostic and treatment methods to preserve female fertility.

Biological and clinical effects of a resveratrol-based multivitamin supplement on intracytoplasmic sperm injection cycles: a single-center, randomized controlled trial

BACKGROUND

Resveratrol display's positive effects on follicle growth and development in preclinical studies while there is scantly information from clinical trials. The aim of this study was to evaluate the biological and clinical impact of a resveratrol-based multivitamin supplement on intracytoplasmatic sperm injection (ICSI) cycles.

METHODS

A randomized, single-center controlled trial conducted at the University Center of Assisted Reproductive Technologies involving 101 women infertile women undergoing ICSI cycles was conducted. A pretreatment with a daily resveratrol based nutraceutical was administered to the Study Group; Control Group received folic acid. The primary outcomes were the number of developed mature follicles (>16 mm), total oocytes and MII oocytes recovered, the fertilization rate and the number of cleavage embryos/blastocysts obtained. Secondary endpoints were the duration and dosage of gonadotropins, the number of embryos for transfer, implantation, biochemical, clinical pregnancy rates, live birth and miscarriage rates.

RESULTS

A significantly higher number of oocytes and MII oocytes were retrieved in the Study Group than in Control Group (p = .03 and p = .04, respectively). A higher fertilization rate (p = .004), more cleavage embryos/patient (p = .01), blastocytes/patients (p = .01) and cryopreserved embryos (p = .03) were obtained in the Study Group. No significant differences in biochemical or clinical pregnancy, live birth, and miscarriage rates were revealed, but a trend to a higher live birth rate was revealed in the Study Group.

CONCLUSIONS

A 3 months period of dietary supplementation with a resveratrol-based multivitamin nutraceutical leads to better biological effects on ICSI cycles.

TRIAL REGISTRATION NUMBER

ClinicalTrials.gov registration identifier: NCT04386499.

Effects of resveratrol on female reproduction: A review

The present review summarizes the current knowledge concerning physiological effects of resveratrol (RSV) with emphasis on the RSV action on female reproductive processes. The review outlines provenance, properties, mechanisms of action, physiological and therapeutic actions of RSV on female reproduction and other physiological processes, as well as areas of possible application of R. This review is based on the search for the related full papers indexed in Medline/Pubmed, Web of Science and SCOPUS databases between the year 2000 and 2021 according to the criteria of preferred reporting items for systematic reviews and meta-analyses extension for scoping reviews and other related guidelines. The analysis of the available information suggests that RSV has a number of properties which enable its influence on various physiological processes including female reproduction at various regulatory levels via various extra- and intracellular signalling pathways. Despite some contradictions and limitations in the available data, they indicate applicability of both stimulatory and inhibitory effects of RSV for control and influence of various reproductive and non-reproductive processes and treatment of their disorders in phytotherapy, animal production, medicine, biotechnology and assisted reproduction. To establish the clinical efficacy of RSV, further high quality studies are needed.

Human Granulosa Cells-Stemness Properties, Molecular Cross-Talk and Follicular Angiogenesis

The ovarian follicle is the basic functional unit of the ovary, comprising theca cells and granulosa cells (GCs). Two different types of GCs, mural GCs and cumulus cells (CCs), serve different functions during folliculogenesis. Mural GCs produce oestrogen during the follicular phase and progesterone after ovulation, while CCs surround the oocyte tightly and form the cumulus oophurus and corona radiata inner cell layer. CCs are also engaged in bi-directional metabolite exchange with the oocyte, as they form gap-junctions, which are crucial for both the oocyte’s proper maturation and GC proliferation. However, the function of both GCs and CCs is dependent on proper follicular angiogenesis. Aside from participating in complex molecular interplay with the oocyte, the ovarian follicular cells exhibit stem-like properties, characteristic of mesenchymal stem cells (MSCs). Both GCs and CCs remain under the influence of various miRNAs, and some of them may contribute to polycystic ovary syndrome (PCOS) or premature ovarian insufficiency (POI) occurrence. Considering increasing female fertility problems worldwide, it is of interest to develop new strategies enhancing assisted reproductive techniques. Therefore, it is important to carefully consider GCs as ovarian stem cells in terms of the cellular features and molecular pathways involved in their development and interactions as well as outline their possible application in translational medicine.

Gallic acid promotes the in vitro development of sheep secondary isolated follicles involving the phosphatidylinositol 3-kinase pathway

This study was conducted to evaluate the effect of addition of gallic acid as the single antioxidant to the base medium for in vitro culture of sheep secondary follicles and if the phosphatidylinositol 3-kinase (PI3K) pathway is involved in the action of gallic acid. Secondary follicles were isolated and cultured for 12 days in α-MEM supplemented with bovine serum albumin (BSA), insulin, glutamine, hypoxanthine, transferrin, selenium, and ascorbic acid (control medium: α-MEM⁺) or in α-MEM supplemented with BSA, insulin, glutamine, hypoxanthine and different concentrations of gallic acid (25, 50 or 100 μM), thus replacing transferrin, selenium and ascorbic acid in the medium. Follicle morphology, glutathione (GSH), and mitochondrial activity, and meiotic resumption were evaluated. Furthermore, inhibition of PI3K pathway was performed by pretreatment with LY294002. After 12 days of culture, the follicle survival in a medium containing 100 μM gallic acid was similar (P > 0.05) to α-MEM⁺ and greater (P < 0.05) compared with other gallic acid concentrations. Antrum formation, follicle diameter, GSH, and mitochondrial activity, and meiotic resumption, however, were greater (P < 0.05) when 100 μM gallic acid was included in the α-MEM⁺ culture medium compared with the control medium. Furthermore, LY294002 inhibited (P < 0.05) follicle survival, development, and meiotic resumption stimulated by 100 μM gallic acid. In conclusion, concentration of 100 μM of gallic acid can be a substitute for transferrin, selenium, and ascorbic acid in the base medium during in vitro culture of sheep secondary follicles, inducing follicle development likely through the PI3K pathway.

Can Some Anticancer Treatments Preserve the Ovarian Reserve?

BACKGROUND

Preventing premature ovarian failure (POF) is a major challenge in oncology. With conventional regimens, cytotoxicity-associated POF involves primordial follicles (PF) pool depletion by apoptosis or overactivation mechanisms, notably mediated by the ABL/TAp63 and PI3K/Akt/mTOR pathways. New anticancer treatments have been designed to target pathways implicated in tumor growth. Although concerns regarding fertility arise with these targeted therapies, we hypothesized that targeted therapies may exert off-tumor effects on PF that might delay POF. We provide an overview of evidence concerning these off-tumor effects on PF. Limitations and future potential implications of these findings are discussed.

DESIGN

PubMed was searched by combining Boolean operators with the following keywords: fertility, ovarian, follicle, anti-tumoral, cancer, targeted, cytotoxic, and chemotherapy.

RESULTS

Cisplatin-related PF apoptosis via the ABL/TAp63 pathway was targeted with a tyrosine kinase inhibitor, imatinib, in mice, but effects were recently challenged by findings on human ovarian xenografts in mice. In cyclophosphamide-treated mice, PI3K/Akt/mTOR pathway inhibition with mTOR inhibitors and AS101 preserved the PF pool. Proteasome and GSK3 inhibitors were evaluated for direct and indirect follicle DNA damage prevention. Surprisingly, evidence for cytotoxic drug association with PF pool preservation was found. We also describe selected non-anticancer molecules that may minimize gonadotoxicity.

CONCLUSION

Not all anticancer treatments are associated with POF, particularly since the advent of targeted therapies. The feasibility of associating a protective drug targeting PF exhaustion mechanisms with cytotoxic treatments should be evaluated, as a way of decreasing the need for conventional fertility preservation techniques. Further evaluations are required for transfer into clinical practice.

IMPLICATIONS FOR PRACTICE

Anticancer therapies are associated with infertility in 10%-70% of patients, which is the result of primordial follicles pool depletion. Alone or associated with gonadotoxic treatments, some targeted therapies may exert favorable off-targets effects on the primordial follicle pool by slowing down their exhaustion. Current evidence of these effects relies on murine models or human in vitro models. Evaluation of these protective strategies in humans is challenging; however, if these results are confirmed with clinical and biological data, it not only could be a new approach to female fertility preservation but also would change standard fertility strategies.

Resveratrol depolarizes the membrane potential in human granulosa cells and promotes mitochondrial biogenesis

OBJECTIVE

To study the biological effects of resveratrol on the growth, electrophysiology, and mitochondrial function of human granulosa cells (h-GCs).

DESIGN

Preclinical study.

SETTING

Electrophysiology laboratory and in vitro fertilization unit.

PATIENT(S)

This study included h-GCs from seven infertile women undergoing assisted reproductive techniques.

INTERVENTION(S)

Human ovarian Granulosa Cell Tumor (GCT) cell line COV434 and h-GCs obtained after oocyte retrieval were cultured in the absence or presence of resveratrol.

MAIN OUTCOME MEASURE(S)

Granulosa cells were evaluated for cell viability and mitochondrial activity. Electrophysiological recordings and evaluation of potassium current (IKur) and Ca₂₊ concentration were also performed.

RESULT(S)

Resveratrol induced mitochondrial activity in a bell-shaped, dose-effect-dependent manner. Specifically, resveratrol treatment (3 μM, 48 hours) increased ATP production and cell viability and promoted the induction of cellular differentiation. These biological changes were associated with mitochondrial biogenesis. Electrophysiological recordings showed that resveratrol reduced the functional expression of an ultra rapid activating, slow inactivating, delayed rectifier potassium current (IKur) that is associated with a plasma membrane depolarization and that promotes an increase in intracellular Ca₂⁺_. CONCLUSION(S): The effects of resveratrol on potassium current and mitochondrial biogenesis in h-GCs could explain the beneficial effects of this polyphenol on the physiology of the female reproductive system. These findings suggest there are therapeutic implications of resveratrol in a clinical setting.

The Stemness of Human Ovarian Granulosa Cells and the Role of Resveratrol in the Differentiation of MSCs-A Review Based on Cellular and Molecular Knowledge

Ovarian Granulosa Cells (GCs) are known to proliferate in the developing follicle and undergo several biochemical processes during folliculogenesis. They represent a multipotent cell population that has been differentiated to neuronal cells, chondrocytes, and osteoblasts in vitro. However, progression and maturation of GCs are accompanied by a reduction in their stemness. In the developing follicle, GCs communicate with the oocyte bidirectionally via gap junctions. Together with neighboring theca cells, they play a crucial role in steroidogenesis, particularly the production of estradiol, as well as progesterone following luteinization. Many signaling pathways are known to be important throughout the follicle development, leading either towards luteinization and release of the oocyte, or follicular atresia and apoptosis. These signaling pathways include cAMP, PI3K, SMAD, Hedgehog (HH), Hippo and Notch, which act together in a complex manner to control the maturation of GCs through regulation of key genes, from the primordial follicle to the luteal phase. Small molecules such as resveratrol, a phytoalexin found in grapes, peanuts and other dietary constituents, may be able to activate/inhibit these signaling pathways and thereby control physiological properties of GCs. This article reviews the current knowledge about granulosa stem cells, the signaling pathways driving their development and maturation, as well as biological activities of resveratrol and its properties as a pro-differentiation agent.

Crosstalk between PTEN/PI3K/Akt Signalling and DNA Damage in the Oocyte: Implications for Primordial Follicle Activation, Oocyte Quality and Ageing

The preservation of genome integrity in the mammalian female germline from primordial follicle arrest to activation of growth to oocyte maturation is fundamental to ensure reproductive success. As oocytes are formed before birth and may remain dormant for many years, it is essential that defence mechanisms are monitored and well maintained. The phosphatase and tensin homolog of chromosome 10 (PTEN)/phosphatidylinositol 3-kinase (PI3K)/protein kinase B (PKB, Akt) is a major signalling pathway governing primordial follicle recruitment and growth. This pathway also contributes to cell growth, survival and metabolism, and to the maintenance of genomic integrity. Accelerated primordial follicle activation through this pathway may result in a compromised DNA damage response (DDR). Additionally, the distinct DDR mechanisms in oocytes may become less efficient with ageing. This review considers DNA damage surveillance mechanisms and their links to the PTEN/PI3K/Akt signalling pathway, impacting on the DDR during growth activation of primordial follicles, and in ovarian ageing. Targeting DDR mechanisms within oocytes may be of value in developing techniques to protect ovaries against chemotherapy and in advancing clinical approaches to regulate primordial follicle activation.

SIRT1 facilitates primordial follicle recruitment independent of deacetylase activity through directly modulating Akt1 and mTOR transcription

In female mammals, the majority of primordial follicles (PFs) are physiologically quiescent, and only a few of them are activated and enter the growing follicle pool. Specific molecules, such as mammalian target of rapamycin (mTOR) and the serine/threonine kinase Akt (AKT), have been proven to be important for PF activation. However, how the transcription of these genes is regulated is not clear. Although activators of mTOR or AKT have been successfully used to rescue the fertility of patients with premature ovarian insufficiency, the low efficacy and unclear safety profile of these drugs hinder their clinical use in the in vitro activation (IVA) of PFs. Here, sirtuin 1 (SIRT1), an NAD-dependent deacetylase, was demonstrated to activate mouse PFs independent of its deacetylase activity. SIRT1 was prominently expressed in pregranulosa cells (pGCs) and oocytes, and its expression was increased during PF activation. PF activation was achieved by either up-regulating SIRT1 with a specific activator or overexpressing SIRT1. Moreover, SIRT1 knockdown in oocytes or pGCs could significantly suppress PF activation. Further studies demonstrated that SIRT1 enhanced both Akt1 and mTOR expression by acting more as a transcription cofactor, directly binding to the respective gene promoters, than as a deacetylase. Importantly, we explored the potential clinical applications of targeting SIRT1 in IVA via short-term treatment of cultured ovaries from mice and human ovarian tissues to activate PFs by applying the SIRT1 activator resveratrol. RSV-induced IVA could be a candidate strategy to develop more efficient procedures for future clinical treatment of infertility.-Zhang, T., Du, X., Zhao, L., He, M., Lin, L., Guo, C., Zhang, X., Han, J., Yan, H., Huang, K., Sun, G., Yan, L., Zhou, B., Xia, G., Qin, Y., Wang, C. SIRT1 facilitates primordial follicle recruitment independent of deacetylase activity through directly modulating Akt1 and mTOR transcription.

Resveratrol Plays a Protective Role against Premature Ovarian Failure and Prompts Female Germline Stem Cell Survival

This study was designed to investigate the protective effect of resveratrol (RES) on premature ovarian failure (POF) and the proliferation of female germline stem cells (FGSCs) at the tissue and cell levels. POF mice were lavaged with RES, and POF ovaries were co-cultured with RES and/or GANT61 in vitro. FGSCs were pretreated with Busulfan and RES and/or GANT61 and co-cultured with M1 macrophages, which were pretreated with RES. The weights of mice and their ovaries, as well as their follicle number, were measured. Ovarian function, antioxidative stress, inflammation, and FGSCs survival were evaluated. RES significantly increased the weights of POF mice and their ovaries as well as the number of follicles, while it decreased the atresia rate of follicles. Higher levels of Mvh, Oct4, SOD2, GPx, and CAT were detected after treatment with RES in vivo and in vitro. RES treatment resulted in significantly lower TNF-α and IL-6 concentrations and an obviously higher IL-10 concentration in the ovaries. In FGSCs, higher Mvh, Oct4, and SOD2 concentrations and lower TNF-α, IL-6, and MDA concentrations were measured in the RES group. Blockage of the Hh signaling pathway reversed the protective effect of RES on FGSCs. In conclusion, RES effectively improved the ovarian function of the POF model and the productive capacity of FGSCs via relieving oxidative stress and inflammation and a mechanism involving the Hh signaling pathway, suggesting that RES is a potential agent against POF and can aid in the survival of FGSCs.

Influence of N-acetyl-L-cysteine against bisphenol a on the maturation of mouse oocytes and embryo development: in vitro study

BACKGROUND

Bisphenol A (BPA), an endocrine disruptor, is a widely used chemical that has adverse effects on animal development and reproduction. The current research aimed to evaluate the effect of BPA on the in vitro maturation (IVM) and subsequent embryo development of mouse oocytes following in vitro fertilization (IVF).

METHODS

IVM was performed in the presence of different concentrations (0, 20, 50, or 100 μg/mL) of BPA. Nuclear maturation, IVF efficiency and embryonic development were determined. The levels of reactive oxygen species (ROS) and glutathione (GSH) in the BPA (50 μg/mL) group were evaluated. We explored the ability of N-acetyl-L-cysteine (NAC) in the IVM medium to rescue the BPA-induced damage by examining changes in nuclear maturation, IVF rate, blastocyst formation, ROS levels and GSH content.

RESULTS

Compared with the control, BPA (50 μg/mL) supplementation during oocyte IVM significantly inhibited nuclear maturation and decreased fertilization and blastocyst formation rates. In addition, BPA exposure increased ROS levels and decreased GSH content in oocytes. The addition of NAC weakened the BPA-induced suppression of nuclear maturation, relieved the BPA-induced downregulation of the fertilization and blastocyst formation rates, and mitigated the increased ROS levels and decreased GSH content.

CONCLUSION

BPA affects mouse oocyte maturation and subsequent early embryonic developmental competence following IVF by increasing intracytoplasmic oxidative stress in mature oocytes. NAC can reduce these harmful effects to a certain extent.