Platelet-derived growth factor modulates the primordial to primary follicle transition

Exploring the potential use of platelet rich plasma (PRP) from adult and umbilical cord blood in murine follicle culture

Ovarian follicle culture is a powerful tool to study follicular physiology and has potential applications in clinical and commercial settings. Despite remarkable progress, recreating folliculogenesis in vitro remains challenging for many mammalian species. This study investigates the impact of platelet-rich plasma (PRP) derived from adult blood (human platelet lysate, hPL) and umbilical cord blood (Umbilical cord plasma, UCP) on murine pre-antral follicle culture and oocyte maturation. Pre-antral follicles were cultured individually for 10 days with fetal bovine serum (FBS) serving as the control and two PRP sources (hPL and UCP) and their activated forms (Ac-hPL and Ac-UCP). The results suggest that neither hPL nor UCP, regardless of activation status, improved follicle culture outcomes compared to FBS. Interestingly, activation did not significantly impact the main functional outcomes such as maturation rates, survival, and growth. Oestradiol secretion and oocyte diameter, often considered hallmarks of follicle quality, did not show significant differences between matured and non-matured oocytes across the treatment groups. However, gene expression analysis revealed a significant upregulation of Gdf-9 and Bmp-15 mRNA levels in oocytes from the Ac-UCP group, regardless of maturation stage, suggesting that the accumulation of the mRNA could be due to potential challenges in translation in the Ac-UCP group. In conclusion, this study challenges the hypothesis that PRP, as a serum source, could improve follicle culture outcomes compared to FBS, the gold standard in murine follicle culture. Further research is needed to understand the species-specific effects of PRP and explore other potential factors affecting follicle culture and oocyte quality.

Potential Therapeutic Options for Premature Ovarian Insufficiency: Experimental and Clinical Evidence

Premature ovarian insufficiency (POI) is a condition in which a woman experiences premature decline in ovarian function before the age of 40 years, manifested by menstrual disorders, decreased fertility, and possibly postmenopausal symptoms such as insomnia, hot flashes, and osteoporosis, and is one of the predominant clinical syndromes leading to female infertility. Genetic, immunologic, iatrogenic and other factors, alone or in combination, have been reported to trigger POI, yet the etiology remains unknown in most cases. The main methods currently used clinically to ameliorate menopausal symptoms due to hypoestrogenemia in POI patients are hormone replacement therapy, while the primary methods available to address infertility in POI patients are oocyte donation and cryopreservation techniques, both of which have limitations to some degree. In recent years, researchers have continued to explore more efficient and safe therapies, and have achieved impressive results in preclinical trials. In this article, we will mainly review the three most popular therapies and their related signaling pathways published in the past ten years, with the aim of providing ideas for clinical applications.

Primary ovarian insufficiency associated with lenvatinib therapy in a patient with hepatocellular carcinoma: A case report

The therapeutic effects of molecular targeted drugs are, in some cases, more pronounced than those of conventional chemotherapy, and their introduction as a standard treatment is increasing. The present report describes a case of ovarian insufficiency in a young woman caused by tyrosine kinase inhibitor lenvatinib. The 25-year-old woman received lenvatinib (8 mg/day) for 98 days as preoperative chemotherapy for hepatocellular carcinoma. Blood testing the day before starting lenvatinib administration indicated 4.40 mIU/ml luteinizing hormone (LH), 5.2 mIU/ml follicle-stimulating hormone (FSH) and age-equivalent hormone values. Amenorrhea occurred after the start of administration, and 48 days later, the LH level was 41.8 mIU/ml and the FSH level was 44 mIU/ml, indicating a decrease in ovarian function. The patient underwent hepatectomy, and 49 days after the end of lenvatinib administration, the LH level had improved to 4.5 mIU/ml and the FSH level had improved to 2.5 mIU/ml. After the hepatectomy, the patient began to have regular menstrual cycles once again. Ovarian toxicity has not been recognized as a side effect of lenvatinib. However, the present report describes primary ovarian insufficiency considered to be caused by this drug. Potential damage to ovarian function may need to be considered when molecular targeted drugs with the same mechanism of action as lenvatinib are used in young women.

Genomic screening of allelic and genotypic transmission ratio distortion in horse

The phenomenon in which the expected Mendelian inheritance is altered is known as transmission ratio distortion (TRD). The TRD analysis relies on the study of the transmission of one of the two alleles from a heterozygous parent to the offspring. These distortions are due to biological mechanisms affecting gametogenesis, embryo development and/or postnatal viability, among others. In this study, TRD phenomenon was characterized in horses using SNP-by-SNP model by TRDscan v.2.0 software. A total of 1,041 Pura Raza Español breed horses were genotyped with 554,634 SNPs. Among them, 277 horses genotyped in trios (stallion-mare-offspring) were used to perform the TRD analysis. Our results revealed 140 and 42 SNPs with allelic and genotypic patterns, respectively. Among them, 63 displayed stallion-TRD and 41 exhibited mare-TRD, while 36 SNPs showed overall TRD. In addition, 42 SNPs exhibited heterosis pattern. Functional analyses revealed that the annotated genes located within the TRD regions identified were associated with biological processes and molecular functions related to spermatogenesis, oocyte division, embryonic development, and hormonal activity. A total of 10 functional candidate genes related to fertility were found. To our knowledge, this is the most extensive study performed to evaluate the presence of alleles and functional candidate genes with transmission ratio distortion affecting reproductive performance in the domestic horse.

Plasma exosomes and contained MiRNAs affect the reproductive phenotype in polycystic ovary syndrome

Anovulation is the main feature of infertile women with polycystic ovary syndrome (PCOS), and there is very limited understanding of the role of plasma exosomes and miRNAs in it. To identify the effect of PCOS patients' plasma exosomes and exosomal miRNAs, we isolated plasma exosomes of PCOS patients and normal women and injected into 8-week-old ICR female mice via tail vein. The changes in estrus cycle, serum hormone levels, and ovarian morphology were observed. KGN cells were cultured and transfected with mimics and inhibitors of differentially expressed exosomal miRNAs (miR-18a-3p, miR-20b-5p, miR-106a-5p, miR-126-3p, and miR-146a-5p) and then tested for steroid hormone synthesis, proliferation, and apoptosis. The results showed that female ICR mice injected with plasma exosomes from PCOS patients presented ovarian oligo-cyclicity. Hormone synthesis and proliferation of granulosa cells were affected by differentially expressed PCOS plasma-derived exosomal miRNAs, of which miR-126-3p having the most evident effect. MiR-126-3p affected the proliferation of granulosa cells by inhibiting PDGFRβ and its downstream PI3K-AKT pathway. Our results demonstrated plasma exosomes and contained miRNAs in PCOS patients affect the estrus cycle of mice, hormone secretion, and proliferation of granulosa cells. This study provides a novel understanding about the function of plasma exosomes and exosomal miRNAs in PCOS.

Adolescent exposure to low-dose Δ9-tetrahydrocannabinol depletes the ovarian reserve in female mice

Cannabis use by adolescents is widespread, but its effects on the ovaries remain largely unknown. Δ9-tetrahydrocannabinol (THC) exerts its pharmacological effects by activating, and in some conditions hijacking, cannabinoid receptors (CBRs). We hypothesized that adolescent exposure to THC affects ovarian function in adulthood. Peripubertal female C57BL/6N mice were given THC (5 mg/kg) or its vehicle, once daily by intraperitoneal injection. Some mice received THC from postnatal day (PND) 30-33 and their ovaries were harvested PND34; other mice received THC from PND30-43, and their ovaries were harvested PND70. Adolescent treatment with THC depleted ovarian primordial follicle numbers by 50% at PND70, 4 weeks after the last dose. The treatment produced primordial follicle activation, which persisted until PND70. THC administration also caused DNA damage in primary follicles and increased PUMA protein expression in oocytes of primordial and primary follicles. Both CB1R and CB2R were expressed in oocytes and theca cells of ovarian follicles. Enzymes involved in the formation (N-acylphosphatidylethanolamine phospholipase D) or deactivation (fatty acid amide hydrolase) of the endocannabinoid anandamide were expressed in granulosa cells of ovarian follicles and interstitial cells. Levels of mRNA for CBR1 were significantly increased in ovaries after adolescent THC exposure, and upregulation persisted for at least 4 weeks. Our results support that adolescent exposure to THC may cause aberrant activation of the ovarian endocannabinoid system in female mice, resulting in substantial loss of ovarian reserve in adulthood. Relevance of these findings to women who frequently used cannabis during adolescence warrants investigation.

Intraovarian condensed platelet cytokines for infertility and menopause-Mirage or miracle?

On a therapeutic landscape unchanged since the 1980's, oocyte donation with IVF still stands as the solitary medical answer to diminished reserve and premature ovarian insufficiency. In 2016, intraovarian platelet-rich plasma (PRP) crossed the horizon as a hopeful reply to these intertwined problems. The once remote mirage of platelet cytokine effects on gene regulation or telomere stabilization has been brought into sharper focus, with current work clarifying how PRP corrects oxidative stress, rectifies tissue hypoxia, downregulates apoptosis, and enhances cellular metabolism. Not yet ready for routine use, this innovative treatment has already offered at least one point of early consensus: How intraovarian PRP results should be classified-Patients are either responders or non-responders. From this it is intriguing that no published PRP protocol has ever reported a supranormal ovarian rebound or hyperstimulation effect. This might be explained by baseline age-related ovarian conditions prevalent among poor responders, but since dysregulated or malignant transformations are also missing in other tissue contexts following autologous PRP treatment, the contribution of some platelet product which intrinsically delimits regenerative action cannot be discounted. Here we summarize results with recent experimental and clinical platelet research, framing those most likely to help advance reproductive endocrinology practice.

Resistant ovary syndrome: Pathogenesis and management strategies

Resistant ovary syndrome (ROS) is a rare and difficult gynecological endocrine disorder that poses a serious risk to women’s reproductive health. The clinical features are normal sex characteristics, regular female karyotype, and usual ovarian reserve, but elevated endogenous gonadotropin levels and low estrogen levels with primary or secondary amenorrhea. Although there have been many case reports of the disease over the past 50 years, the pathogenesis of the disease is still poorly understood, and there are still no effective clinical management strategies. In this review, we have collected all the current reports on ROS and summarized the pathogenesis and treatment strategies for this disease, intending to provide some clinical references for the management and treatment of this group of patients and provide the foothold for future studies.

Effect of endometrial cell-conditioned medium and platelet-rich plasma on the developmental competence of mouse preantral follicles: An in vitro study

Objective

The aim of this study was to evaluate the impacts of platelet-rich plasma (PRP) and conditioned medium (CM) derived from endometrial stromal cells on mouse preantral follicle culture in a two-dimensional system to produce competent mature oocytes for fertilization.

Methods

In total, 240 preantral follicles were isolated from female mouse ovarian tissue and divided into four groups. The preantral follicles were isolated three times for each group and then cultured, respectively, in the presence of alpha minimum essential medium (control), PRP, CM, and PRP+CM. The in vitro growth, in vitro maturation, and cleavage percentage of the preantral follicles were investigated. Immunocytochemistry (IHC) was also conducted to monitor the meiotic progression of the oocytes. Additionally, the mRNA expression levels of the two folliculogenesis-related genes (Gdf9 and Bmp15) and two apoptosis-related genes (Bcl2 and Bax) were investigated using real-time polymerase chain reaction.

Results

In the PRP, CM, and PRP+CM groups, the preantral follicle maturation (evaluated by identifying polar bodies) were greater than the control group. The cleavage rate in the CM, and PRP+CM groups were also greater than the control group. IHC analysis demonstrated that in each treatment group, meiotic spindle was normal. In the PRP+CM group, the gene expression levels of Bmp15, Gdf9, and Bcl2 were greater than in the other groups. The Bax gene was more strongly expressed in the PRP and control groups than in the other groups.

Conclusion

Overall, the present study suggests that the combination of CM and PRP can effectively increase the growth and cleavage rate of mouse preantral follicles in vitro.

Co-Expression Network and Integrative Analysis of Metabolome and Transcriptome Uncovers Biological Pathways for Fertility in Beef Heifers

Reproductive failure remains a significant challenge to the beef industry. The omics technologies have provided opportunities to improve reproductive efficiency. We used a multistaged analysis from blood profiles to integrate metabolome (plasma) and transcriptome (peripheral white blood cells) in beef heifers. We used untargeted metabolomics and RNA-Seq paired data from six AI-pregnant (AI-P) and six nonpregnant (NP) Angus-Simmental crossbred heifers at artificial insemination (AI). Based on network co-expression analysis, we identified 17 and 37 hub genes in the AI-P and NP groups, respectively. Further, we identified TGM2, TMEM51, TAC3, NDRG4, and PDGFB as more connected in the NP heifers’ network. The NP gene network showed a connectivity gain due to the rewiring of major regulators. The metabolomic analysis identified 18 and 15 hub metabolites in the AI-P and NP networks. Tryptophan and allantoic acid exhibited a connectivity gain in the NP and AI-P networks, respectively. The gene–metabolite integration identified tocopherol-a as positively correlated with ENSBTAG00000009943 in the AI-P group. Conversely, tocopherol-a was negatively correlated in the NP group with EXOSC2, TRNAUIAP, and SNX12. In the NP group, α-ketoglutarate-SMG8 and putrescine-HSD17B13 were positively correlated, whereas a-ketoglutarate-ALAS2 and tryptophan-MTMR1 were negatively correlated. These multiple interactions identified novel targets and pathways underlying fertility in bovines.

Impact of imatinib administration on the mouse ovarian follicle count and levels of intra-ovarian proteins related to follicular quality

Objective

The impact of imatinib, a tyrosine kinase inhibitor, on ovarian follicles and several proteins related to follicular function and apoptosis was investigated in mice.

Methods

Saline, cyclophosphamide (Cp; 50 or 75 mg/kg), or imatinib (7.5 or 15 mg/kg) was injected once intraperitoneally into female B6D2F1 mice (18 mice in each group). In multiple ovarian sections, the number of various types of follicles and the proportion of good-quality (G1) follicles were counted. The levels of six proteins (anti-Müllerian hormone [AMH], BCL-xL, BAX, acid sphingomyelinase [A-SMase], caspase-3, and α-smooth muscle actin [α-SMA]) within the whole ovaries were quantified using Western blots.

Results

Compared to the saline group, a significant reduction of the primordial follicle count was observed in the group treated with imatinib 7.5 and 15 mg/kg, as well as in the group treated with Cp 75 mg/kg. Administration of Cp significantly decreased the proportion of G1 primordial follicles, but administration of imatinib did not. No differences in the AMH, anti-apoptotic BCLX-L, pro-apoptotic BAX, and A-SMase levels in the ovarian tissues were observed among the five groups. However, caspase-3 and α-SMA levels were significantly higher in the imatinib and Cp groups than in the saline group.

Conclusion

The administration of imatinib to mice significantly reduced the primordial follicle count and increased the protein levels of caspase-3 and α-SMA. Our findings suggest that imatinib potentially exerts ovarian toxicity via apoptotic processes, similarly to Cp.

Increased phosphatase regenerating liver-1 trigger vascular remodeling in injured ovary via platelet-derived growth factor signaling pathway

Background

Vascular abnormalities in the ovary cause infertility accompanied by ovarian insufficiency due to a microenvironment of barren ovarian tissues. Placenta-derived mesenchymal stem cells (PD-MSCs, Naïve) treatment in ovarian dysfunction shows angiogenic effect, however, the therapeutic mechanism between ovarian function and vascular remodeling still unclear. Therefore, we examined whether by phosphatase regenerating liver-1 (PRL-1), which is correlated with angiogenesis in reproductive systems, overexpressed PD-MSCs could maximize the angiogenic effects in an ovarian tissues injured of rat model with partial ovariectomy and their therapeutic mechanism by enhanced vascular function via PDGF signaling.

Methods

PD-MSCs^PRL-1 (PRL-1) were generated by nonviral AMAXA gene delivery system and analyzed the vascular remodeling and follicular development in ovary. One week after Sprague–Dawley (SD) rats ovariectomy, Naïve and PRL-1 was transplanted. The animals were sacrificed at 1, 3 and 5 weeks after transplantation and vascular remodeling and follicular development were analyzed. Also, human umbilical vein endothelial cells (HUVECs) and ovarian explantation culture were performed to prove the specific effects and mechanism of PRL-1.

Results

Vascular structures in ovarian tissues (e.g., number of vessels, thickness and lumen area) showed changes in the Naïve and PRL-1-overexpressed PD-MSC (PRL-1) transplantation (Tx) groups compared to the nontransplantation (NTx) group. Especially, PRL-1 induce to increase the expression of platelet-derived growth factor (PDGF), which plays a role in vascular remodeling as well as follicular development, compared to the NTx. Also, the expression of genes related to pericyte and vascular permeability in arteries was significantly enhanced in the PRL-1 compared to the NTx (p < 0.05). PRL-1 enhanced the vascular formation and permeability of human umbilical vein endothelial cells (HUVECs) via activated the PDGF signaling pathway.

Conclusions

Our results show that PRL-1 restored ovarian function by enhanced vascular function via PDGF signaling pathway. These findings offer new insight into the effects of functionally enhanced stem cell therapy for reproductive systems and should provide new avenues to develop more efficient therapies in degenerative medicine.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13287-022-02772-9.

Pathways and factors regulated by bone marrow-derived stem cells in human ovarian tissue

OBJECTIVE

To describe molecular and paracrine signaling changes produced by human bone marrow-derived stem cells (BMDSC) in human ovarian cortex.

DESIGN

Experimental study.

SETTING

University hospital research laboratories.

PATIENT(S)

Ovarian cortex from poor responder women (n = 7).

ANIMALS

Immunodeficient NOD/SCID female mice (n = 18).

INTERVENTION(S)

Human ovarian cortex strips were xenografted into ovariectomized NOD/SCID female mice. A week later, mice were infused with phosphate-buffered saline, 1 × 106 BMDSC, or 3 × 105 CD133+ cells via tail vein. Gene expression changes and enriched pathways were assessed by RT2 Profiler Arrays. Several upregulated genes were validated in individual samples by real-time quantitative PCR, and transcriptomic results were reinforced by a proteomic assessment.

MAIN OUTCOME MEASURE(S)

Gene expression changes, enriched Kyoto Encyclopedia of Genes and Genomes pathways, and paracrine factors.

RESULT(S)

Seventy-four Kyoto Encyclopedia of Genes and Genomes pathways were upregulated, with the PI3K-Akt signaling pathway the most enriched after BMDSC and CD133 treatments. The greatest transcriptomic changes were seen on day 14 in the BMDSC group, affecting the regulation of paracrine factors such as KITLG, THBS1, SERPINF1, and TIMP2. Proteomics data verified changes in FoxO signaling, actin cytoskeleton remodeling, and apoptosis by BMDSC.

CONCLUSION(S)

We identified paracrine factors and pathways regulated by BMDSC that may be future targets of treatment for the increasing number of poor responder women. Our findings suggest that BMDSC upregulated soluble factors such as KITLG, THBS1, SERPINF1, and TIMP2 as well as PI3K-Akt signaling and regulation of actin cytoskeleton pathways. The identification of these putative underlying mechanisms informs future experiments aiming to optimizing clinical application of BMDSC.

Intraovarian injection of platelet-rich plasma in assisted reproduction: too much too soon?

The prospect of ovarian rejuvenation offers the tantalising prospect of treating age-related declines in fertility or in pathological conditions such as premature ovarian failure. The concept of ovarian rejuvenation was invigorated by the indication of the existence of oogonial stem cells (OSCs), which have been shown experimentally to have the ability to differentiate into functional follicles and generate oocytes; however, their clinical potential remains unknown. Furthermore, there is now growing interest in performing ovarian rejuvenation in situ. One proposed approach involves injecting the ovary with platelet rich plasma (PRP).

PRP is a component of blood that remains after the in vitro removal of red and white blood cells. It contains blood platelets, tiny anucleate cells of the blood, which are responsible for forming athrombus to prevent bleeding. In addition, PRP contains an array of cytokines and growth factors, as well as a number of small molecules.The utility ofPRP has been investigatedin a range of regenerative medicine approaches and has been shown to induce differentiation of a range of cell types, presumably through the action of cytokines.

A handful ofcasereports have described the use of PRP injections into the ovaryin the human, and while these clinical data report promising results, knowledge on the mechanisms and safety of PRP injections into the ovary remain limited.In this article, we summarise some of the physiological detail of platelets and PRP, before reviewing the existing emerging literature in this area. We then propose potential mechanisms by which PRP may be eliciting any effects before reflecting on some considerations for future studies in the area. Importantly, on the basis of our existing knowledge, we suggest that immediate use of PRP in clinical applications is perhaps premature and further fundamental and clinical research on the nature of ovarian insufficiency, as well as the mechanism by which PRP may act on the ovary, is needed to fully understand this promising development.

Reduced retinoic acid synthesis accelerates prophase I and follicle activation

In female mammals, reproductive potential is determined during fetal life by the formation of a non-renewable pool of primordial follicles. Initiation of meiosis is one of the defining features of germ cell differentiation and is well established to commence in response to retinoic acid. WIN 18,446 inhibits the conversion of retinol to retinoic acid, and therefore it was used to explore the impact of reduced retinoic acid synthesis on meiotic progression and thus germ cell development and subsequent primordial follicle formation. e13.5 mouse fetal ovaries were cultured in vitro and treated with WIN 18,446 for the first 3 days of a total of up to 12 days. Doses as low as 0.01 µM reduced transcript levels of the retinoic acid response genes Stra8 and Rarβ without affecting germ cell number. Higher doses resulted in germ cell loss, rescued with the addition of retinoic acid. WIN 18,446 significantly accelerated the progression of prophase I; this was seen as early as 48 h post treatment using meiotic chromosome spreads and was still evident after 12 days of culture using Tra98/Msy2 immunostaining. Furthermore, ovaries treated with WIN 18,446 at e13.5 but not at P0 had a higher proportion of growing follicles compared to vehicle controls, thus showing evidence of increased follicle activation. These data therefore indicate that retinoic acid is not necessary for meiotic progression but may have a role in the regulation of its progression and germ cell survival at that time and provide evidence for a link between meiotic arrest and follicle growth initiation.

Bisphenol analogs AF and S: Effects on cell status and production of angiogenesis-related factors by COV434 human granulosa cell line

While Bisphenol A (BPA) has been a requisite plastic additive, as an endocrine disruptor it has been associated with adverse health effects including ovarian disorders. Following implemented restrictions on BPA usage, it is replaced by alternative bisphenols, biological effects of which have not been adequately investigated. Our study examined effects of bisphenols AF (BPAF) and S (BPS), on the human ovarian granulosa cell line COV434, and compared them with BPA, with the focus on cell viability (10^-9-10^-4 M) and angiogenesis-related factors (10^-9-10^-5 M), relevant for both the follicle development and ovarian pathologies: vascular endothelial growth factor A (VEGF-A), platelet-derived growth factor AA (PDGF-AA), and matrix metalloproteinase 9 (MMP-9). Each bisphenol impaired cell viability and increased generation of intracellular reactive oxygen species at the highest concentration (10^-4 M). While VEGF-A production in BPAF-treated groups did not differ from the control, all doses of BPS and BPA caused a marked reduction in VEGF-A output. Nevertheless, the alterations in VEGF-A production were not caused by the impact on VEGFA gene expression since there were no indications of VEGFA downregulation in the presence of either BPS or BPA. Interestingly, we observed a similar pattern of PDGF-AA output reduction in BPS- and BPA-treated groups to that of VEGF-A production. BPAF and BPS (10^-5 M) increased MMP9 expression, however, this effect was not reflected by the increase in MMP-9 production. The results obtained demonstrate that the novel bisphenol analogs are not inert with respect to the ovarian cells, and their effects might contribute to dysregulation of granulosa cells functions.

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.

Evaluation of expression and serum concentration of anti-Mullerian hormone as a follicle growth marker following consumption of fennel and flaxseed extract in first-generation mice pups

Background

The aim of the present study was to assess the expression and serum level of AMH in first-generation female mice pups following fennel and flaxseed consumption.

Methods

Twenty pregnant NMRI mice were allocated into four groups including control (CTL), fennel (FV), flaxseed (LU) and FV+ LU. Sixty-four female offsprings after lactation period, received the same regimen as their mothers for 56 and 240 days. The ovarian follicles development, serum concentration of AMH, as well as gene and protein expression of AMH were evaluated in the female offsprings at post-natal day 56 (PND56) and 240 (PND240).

Results

The number of total growing follicles were raised in the FV group in compression to the all experimental groups. In contrast, LU group showed a marked decrease in their numbers. The highest level of serum AMH was seen in the FV-diet mice, whereas LU negatively affected it. The expression level of AMH also increased in the FV and FV + LU groups, while a reduction was observed in the LU group. As well, IHC data showed that the number of AMH-positive cells in almost ovarian follicles of FV and FV + LU-treated mice was in compared to those of the LU group.

Conclusions

The overall effect of fennel treatment (alone and in combination with flaxseed) on ovary might be maintain primordial follicle storage through increased expression and serum level of AMH.

Heterogeneity and Dynamics of Vasculature in the Endocrine System During Aging and Disease

The endocrine system consists of several highly vascularized glands that produce and secrete hormones to maintain body homeostasis and regulate a range of bodily functions and processes, including growth, metabolism and development. The dense and highly vascularized capillary network functions as the main transport system for hormones and regulatory factors to enable efficient endocrine function. The specialized capillary types provide the microenvironments to support stem and progenitor cells, by regulating their survival, maintenance and differentiation. Moreover, the vasculature interacts with endocrine cells supporting their endocrine function. However, the structure and niche function of vasculature in endocrine tissues remain poorly understood. Aging and endocrine disorders are associated with vascular perturbations. Understanding the cellular and molecular cues driving the disease, and age-related vascular perturbations hold potential to manage or even treat endocrine disorders and comorbidities associated with aging. This review aims to describe the structure and niche functions of the vasculature in various endocrine glands and define the vascular changes in aging and endocrine disorders.

A case of ovarian stimulation for fertility preservation in a patient with Philadelphia chromosome-positive acute lymphoblastic leukemia after treatment with dasatinib

Tyrosine kinase inhibitors (TKIs) are effective for treating Philadelphia chromosome-positive acute lymphoblastic leukemia (Ph+ALL). However, the use of TKIs may decrease the number of collected oocytes during fertility preservation procedures. We report the case of a 19-year-old patient with Ph+ALL for whom 21 oocytes were frozen after controlled ovarian stimulation was initiated 2 days after the completion of 28 days of remission induction therapy with dasatinib. After collecting the oocytes, consolidation therapy was initiated immediately, and a hematopoietic stem cell transplant from her younger brother was scheduled. It is believed that a 2-day withdrawal period is sufficient for fertility preservation or that the effect of dasatinib on the number of oocytes obtained is minimal.

Risks of molecular targeted therapies to fertility and safety during pregnancy: a review of current knowledge and future needs

INTRODUCTION

As the population of young cancer survivors is increasing and a trend toward postponing pregnancy later in life is reported, more efforts are focused toward understanding treatment-induced sequelae, in particular, the effects of cancer and/or treatment on fertility.

AREA COVERED

Whereas the fertility risk of cytotoxic agents for both men and women is well recognized, the impact of molecular-targeted therapy (MTT) on fertility parameters, their teratogenic potential and pregnancy outcome/management in case of an accidental exposure are not established. We update available clinical data on the impact of new MTTs on fertility in both sexes, their potential teratogenic effects and the outcome of pregnancy during accidental exposure. Agents are categorized by class and the potential relevance of their target signaling pathways to gonadal maturation.

EXPERT OPINION

The majority of MTTs have worrying preclinical data discouraging their use during pregnancy and reinforcing the idea that they can induce impairment in gonadal function. However, it does not mean that all MTTs result in permanent infertility and that they should be completely avoided during pregnancy. The current review provides a critical evaluation on the most commonly used MTTs, offering a possible guide for clinicians.

An update on platelet-rich plasma (PRP) therapy in endometrium and ovary related infertilities: clinical and molecular aspects

Administration of platelet-rich plasma (PRP) is one of the well-recommended strategies for the treatment of endometrium- and ovary-associated infertility. Due to the autologous source of PRP, minimal risks for disease transmission and immunogenic and allergic responses are expected in this method. Despite the extensive use of PRP in medicine, its precise mechanism of action in endometrial and ovarian tissues is still unknown. Nevertheless, the induction of cell proliferation, chemotaxis, regeneration, extracellular matrix synthesis, remodeling, angiogenesis, and epithelialization are the main pathways for PRP to affect female reproductive organs. Given the promising results of previous studies, it is necessary to standardize PRP preparation protocols for different therapeutic purposes and also clearly determine appropriate inclusion and exclusion criteria for recruiting patients. In the current review, we presented a summary of studies on PRP therapy for endometrium- and ovary-associated infertility with a focus on the possible mechanisms by which PRP enhances endometrial receptivity and regenerates ovarian function.Abbreviations: PRP: platelet-rich plasma; ART: assisted reproductive technology; POF: premature ovarian failure; TGF: transforming growth factors; PDGF: platelet-derived growth factors; IGF-I: insulin-like growth factor-1; HGF: hepatocyte growth factor; EGF: epidermal growth factor; FGF: fibroblast growth factor; VEGF: vascular endothelial growth factor; ADP: adenosine diphosphate, ATP: adenosine triphosphate; PDGF: platelet-derived growth factor; COX2: cyclooxygenase-2; TP53: tumor protein 53; ER-α: estrogen receptors alpha; ER-β: estrogen receptors beta; PR: progesterone receptor; RIF: recurrent implantation failure; G-CSF: granulocyte colony-stimulating factor; iNOS: inducible nitric oxide synthase; NF-kβ: nuclear factor kappa beta; MMPs: matrix metalloproteinases; Col1a1: collagen type I alpha 1; IL: interleukin; FSH: follicle-stimulating hormone; AMH: anti-Mullerian hormone; GDF-9: growth differentiation factor 9.

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.

Immunohistological localisation of growth factors in stroma and interstitial gland tissue of goat (Capra hircus) ovary

The growth factors platelet derived growth factor (PDGF), transforming growth factor alpha (TGF-α) and transforming growth factor beta (TGF-β) have been demonstrated to stimulate the in vitro prolife­ration of theca and granulosa cells in different animals. The present study was conducted to localise the growth factors PDGF, TGF-α and TGF-β in different types of interstitial cells and stromal cells of normal cycling goat ovaries. Tissue fixed in formalin was processed through a graded series of alcohols and embedded in paraffin wax. The sections were immunohistochemically stained with antibo­dies against PDGF, TGF-α and TGF-β. The binding affinity of interstitial cells and stromal cells were observed and photographed. The staining pattern of PDGF, TGF-α and TGF-β was mild to strong in stromal cells. The primary and secondary interstitial cells exhibited varied staining patterns for all studied growth factors. These findings in goat suggests that PDGF, TGF-α, TGF-β were potentially an important autocrine regulator of different cell functions and possibly a paracrine regulator of ovarian cell function at various development stages.

Implications of Nonphysiological Ovarian Primordial Follicle Activation for Fertility Preservation

In recent years, ovarian tissue cryopreservation has rapidly developed as a successful method for preserving the fertility of girls and young women with cancer or benign conditions requiring gonadotoxic therapy, and is now becoming widely recognized as an effective alternative to oocyte and embryo freezing when not feasible. Primordial follicles are the most abundant population of follicles in the ovary, and their relatively quiescent metabolism makes them more resistant to cryoinjury. This dormant pool represents a key target for fertility preservation strategies as a resource for generating high-quality oocytes. However, development of mature, competent oocytes derived from primordial follicles is challenging, particularly in larger mammals. One of the main barriers is the substantial knowledge gap regarding the regulation of the balance between dormancy and activation of primordial follicles to initiate their growing phase. In addition, experimental and clinical factors also affect dormant follicle demise, while the mechanisms involved remain largely to be elucidated. Moreover, most of our basic knowledge of these processes comes from rodent studies and should be extrapolated to humans with caution, considering the differences between species in the reproductive field. Overcoming these obstacles is essential to improving both the quantity and the quality of mature oocytes available for further fertilization, and may have valuable biological and clinical applications, especially in fertility preservation procedures. This review provides an update on current knowledge of mammalian primordial follicle activation under both physiological and nonphysiological conditions, and discusses implications for fertility preservation and priorities for future research.

Exosomes: Emerging biomarkers and targets in folliculogenesis and endometriosis

An appropriate connection of the cells in the ovary follicles is vital for a healthy ovule maturation and fertilization, and also for endometrium preparation for implantation that can cause endometriosis. Cellular communication within the follicle and endometrial epithelium involve many signaling molecules. Recent studies indicate that cellular communication can be enclosed by secretion and absorption of small membrane carriers which are named extracellular vesicles including exosomes and microvesicles. Understanding and defining these EVs (Extracellular vesicles) population are important for future studies and clinical translation. Here, we describe the various important cargos which are carried by exosomes during folliculogenesis and endometriosis. Additionally, the current knowledge of exosomes and their cargo within the FF (Follicular fluid) during the folliculogenesis and also in the intrauterine cavity which are involved in endometriosis lesions have also been summarized. Considering the potential importance of this form of the cell to cell communication in the reproductive system, the vital issues under discussion lead to a new insight in this rapidly expanding field and it may be an interesting approach for diagnostic, prognostic and especially therapeutic strategies in the field of infertility and assisted reproductive technology (ART).

Long-term imatinib diminishes ovarian reserve and impacts embryo quality

PURPOSE

Tyrosine kinase inhibitors (TKIs) such as imatinib are commonly used chemotherapeutics, but the effects of long-term treatments on reproductive outlook for cancer survivors are unknown. The purpose of this study was to examine the effects of long-term imatinib treatments on follicle development and embryo quality. Since prospective studies are not possible in healthy humans, we have incorporated a commonly used mouse model.

METHODS

Adult female mice were treated with daily IP injections of imatinib for 4-6 weeks. Liquid chromatography-mass spectrometry was used to measure imatinib in serum and ovarian tissues. At the end of treatments, females were superovulated and mated to yield fertilized embryos. Oocytes and embryos were collected from oviducts, assessed for development by microscopy, and fertilized embryos were cultured in vitro. Blastocysts were fixed and stained for differential cell counts.

RESULTS

Long-term imatinib treatments caused a shift in follicle development, with imatinib-treated females having fewer primordial follicles, but an increase in primary and secondary follicles (P < 0.05). There was no effect on ovulation or fertilization rates. However, blastocysts from imatinib-treated females had fewer total cells (P < 0.05) and a significant shift from inner cell mass to increased trophectoderm cells.

CONCLUSION

This pilot study indicates that long-term TKI treatments may have significant impact on ovarian reserve and embryo developmental capacity. More studies are needed in other model systems to determine the long-term impact of TKIs in patients. Knowing the potential effects of chemotherapeutics on reproductive outlook is critical for quality of life and more research is needed.

The use of autologous platelet-rich plasma (PRP) versus no intervention in women with low ovarian reserve undergoing fertility treatment: a non-randomized interventional study

PURPOSE

To investigate the impact of a 3-month course of intracortical injections of autologous platelet-rich plasma (PRP) upon ovarian reserve markers versus no intervention in women with low ovarian reserve prior to undergoing assisted reproductive technology (ART).

METHODS

Prospective controlled, non-randomized comparative study conducted in a private fertility clinic, in Venezuela. Women with abnormal ovarian reserve markers (FSH, AMH and AFC) who declined oocyte donation were allocated to one of the following groups according to patient choice: monthly intracortical ovarian PRP injections for three cycles, or no intervention. Primary outcomes were the change in FSH, AMH and AFC pre- and post-treatment. Secondary outcomes included the number of oocytes collected and fertilized, biochemical/clinical pregnancy rates and miscarriage and live birth rates.

RESULTS

Eighty-three women were included, of which 46 received PRP treatment and 37 underwent no intervention. Overall median age was 41 years (IQR 39-44). There were no demographic differences between the study groups. At the 3-month follow-up, women treated with PRP experienced a significant improvement in FSH, AMH and AFC, whereas there was no change in the control group. Furthermore, overall rates of biochemical (26.1% versus 5.4%, P = 0.02) and clinical pregnancy (23.9% versus 5.4%, P = 0.03) were higher in the PRP group, while there was no difference in the rates of first trimester miscarriage and live birth between groups.

CONCLUSION

PRP injections are effective and safe to improve markers of low ovarian reserve prior to ART, although further evidence is required to evaluate the impact of PRP on pregnancy outcomes.

Primary ovarian insufficiency associated with pazopanib therapy in a breast angiosarcoma patient: A CARE-compliant case report

RATIONAL

The growing population of young cancer survivors and a trend toward postponing pregnancy until later years in life are leading to a deeper attention towards understanding treatment-induced sequelae, and, in particular, the effects of cancer and/or treatment on fertility. Nowadays, the infertility risks potentially associated with molecular targeted therapies are not established, and clinical reports are sparse. Moreover, the increasing use of molecular targeted drugs in the adjuvant setting and in diseases with better prognosis makes preservation of fertility a major topic in current research.

PATIENT'S CONCERNS

Here, we report the case of an 18-year-old woman, with a 3-cm superficial lump of the right breast, who had no remarkable family or medical history. Menarche had occurred at the age of 14 years, with normal regular periods.

DIAGNOSIS

High-grade angiosarcoma, with metastatic progression and multiple relapse, was diagnosed.

INTERVENTIONS

After diagnosis, right radical mastectomy was carried out with no evidence of residual disease. No adjuvant treatment was delivered. Lymph node metastasis were found later and chemotherapy with doxorubicin 25 mg/m/day and ifosfamide 1 g/m/day (both on days 1-3) every 21 days was administered. During treatment, the patient reported menstrual irregularities but no amenorrhea. Due to further local relapse a few years later, the patient was treated for progressive metastatic disease with gemcitabine 1000 mg/m on days 1 and 8 every 21 days for 6 cycles, and underwent surgery, followed by pegylated liposomal doxorubicin, 50 mg/m on day 1 every 28 days. After further disease progression 5 years after first diagnosis, pazopanib was administered at a dose of 800 mg daily for 10 months.

OUTCOMES

The patient experienced a transient ovarian insufficiency possibly due to pazopanib. Since amenorrhea developed within 2 months from the initiation of pazopanib treatment and menses returned regularly only after discontinuation of the treatment itself.

LESSONS

This is the first case report that strongly suggests a correlation between pazopanib exposure and development of ovarian insufficiency. Our case tantalizes to inspire additional preclinical and clinical research on the true incidence, possible dose dependence, and reversibility of pazopanib (and other TKIs) -induced ovarian failure.

Establishment and depletion of the ovarian reserve: physiology and impact of environmental chemicals

The reproductive life span in women starts at puberty and ends at menopause, following the exhaustion of the follicle stockpile termed the ovarian reserve. Increasing data from experimental animal models and epidemiological studies indicate that exposure to a number of ubiquitously distributed reproductively toxic environmental chemicals (RTECs) can contribute to earlier menopause and even premature ovarian failure. However, the causative relationship between environmental chemical exposure and earlier menopause in women remains poorly understood. The present work, is an attempt to review the current evidence regarding the effects of RTECs on the main ovarian activities in mammals, focusing on how such compounds can affect the ovarian reserve at any stages of ovarian development. We found that in rodents, strong evidence exists that in utero, neonatal, prepubescent and even adult exposure to RTECs leads to impaired functioning of the ovary and a shortening of the reproductive lifespan. Regarding human, data from cross-sectional surveys suggest that human exposure to certain environmental chemicals can compromise a woman's reproductive health and in some cases, correlate with earlier menopause. In conclusion, evidences exist that exposure to RTECs can compromise a woman's reproductive health. However, human exposures may date back to the developmental stage, while the adverse effects are usually diagnosed decades later, thus making it difficult to determine the association between RTECs exposure and human reproductive health. Therefore, epidemiological surveys and more experimental investigation on humans, or alternatively primates, are needed to determine the direct and indirect effects caused by RTECs exposure on the ovary function, and to characterize their action mechanisms.

Imatinib treatments have long-term impact on placentation and embryo survival

Imatinib is an oral chemotherapeutic used primarily to treat chronic myeloid leukemia (CML) and gastrointestinal stromal tumors (GIST). The potential effects of cancer treatments on a patient’s future fertility  are a major concern affecting the quality of life for cancer survivors. The effects of imatinib on future fertility are unknown. It is teratogenic. Therefore, patients are advised to stop treatment before pregnancy. Unfortunately, CML and GIST have high rates of recurrence in the absence of the drug, therefore halting imatinib during pregnancy endangers the mother. Possible long-term (post-treatment) effects of imatinib on reproduction have not been studied. We have used a mouse model to examine the effects of imatinib on the placenta and implantation after long-term imatinib exposure. We found significant changes in epigenetic markers of key imprinted genes in the placenta. There was a significant decrease in the labyrinth zone and vasculature of the placenta, which could impact fetal growth later in pregnancy. These effects on placental growth occurred even when imatinib was stopped prior to pregnancy. These results indicate potential long-term effects of imatinib on pregnancy and implantation. A prolonged wash-out period prior to pregnancy or extra monitoring for possible placental insufficiency may be advisable.

Environmental toxicant induced epigenetic transgenerational inheritance of ovarian pathology and granulosa cell epigenome and transcriptome alterations: ancestral origins of polycystic ovarian syndrome and primary ovarian insufiency

Two of the most prevalent ovarian diseases affecting women's fertility and health are Primary Ovarian Insufficiency (POI) and Polycystic Ovarian Syndrome (PCOS). Previous studies have shown that exposure to a number of environmental toxicants can promote the epigenetic transgenerational inheritance of ovarian disease. In the current study, transgenerational changes to the transcriptome and epigenome of ovarian granulosa cells are characterized in F3 generation rats after ancestral vinclozolin or DDT exposures. In purified granulosa cells from 20-day-old F3 generation females, 164 differentially methylated regions (DMRs) (P < 1 x 10-6) were found in the F3 generation vinclozolin lineage and 293 DMRs (P < 1 x 10-6) in the DDT lineage, compared to controls. Long noncoding RNAs (lncRNAs) and small noncoding RNAs (sncRNAs) were found to be differentially expressed in both the vinclozolin and DDT lineage granulosa cells. There were 492 sncRNAs (P < 1 x 10-4) in the vinclozolin lineage and 1,085 sncRNAs (P < 1 x 10-4) in the DDT lineage. There were 123 lncRNAs and 51 lncRNAs in the vinclozolin and DDT lineages, respectively (P < 1 x 10-4). Differentially expressed mRNAs were also found in the vinclozolin lineage (174 mRNAs at P < 1 x 10-4) and the DDT lineage (212 mRNAs at P < 1 x 10-4) granulosa cells. Comparisons with known ovarian disease associated genes were made. These transgenerational epigenetic changes appear to contribute to the dysregulation of the ovary and disease susceptibility that can occur in later life. Observations suggest that ancestral exposure to toxicants is a risk factor that must be considered in the molecular etiology of ovarian disease.

Programmed cell death in the human ovary

During a woman's reproductive life, only about 400 primordial follicles will develop into a preovulatory follicle and undergo ovulation, releasing an oocyte available for fertilization. The process of formation and selection of these follicles is complex and involves a multistep process characterized by a balance between survival and death of the oocytes and the surrounding follicular cells. Although the mechanisms underlying such process are not completely clarified yet, it is common idea that they can occur through various types of programmed cellular death (PCD). Since atresia is the principal destiny of the ovarian follicles, it is relevant to understand how this process takes place and how it is regulated. In this review, after a summary description of folliculogenesis in humans, the main mechanisms of atresia reported to occur during folliculogenesis from birth to adult age, in the human ovary and in other mammals when appropriate, are described.

Micro-RNAs involved in cellular proliferation have altered expression profiles in granulosa of young women with diminished ovarian reserve

PURPOSE

The study aims to determine differences in micro-RNA (miRNA) expression in granulosa (GC) and cumulus cells (CC) between young women with diminished ovarian reserve (DOR) or normal ovarian reserve (NOR). Secondary objective was to identify downstream signaling pathways that could ultimately indicate causes of lower developmental competence of oocytes from young women with DOR.

METHODS

The method of the study is prospective cohort study.

RESULTS

Of the miRNA, 125 are differentially expressed in GC between DOR and NOR. Only nine miRNA were different in CC; therefore, we focused analysis on GC. In DOR GC, miR-100-5p, miR-16-5p, miR-30a-3p, and miR-193a-3p were significantly downregulated, while miR-155-5p, miR-192-5p, miR-128-3p, miR-486-5p, miR130a-3p, miR-92a-3p, miR-17-3p, miR-221-3p, and miR-175p were increased. This pattern predicted higher cell proliferation in the DOR GC. The primary pathways include MAPK, Wnt, and TGFbeta.

CONCLUSIONS

The miRNA pattern identified critical functions in cell proliferation and survival associated with DOR. GC in women with DOR seems to respond differently to the LH surge.

Ovarian angiogenesis in polycystic ovary syndrome

Polycystic ovary syndrome (PCOS) is the most prevalent endocrine pathology among women in reproductive age. Its main symptoms are oligo or amenorrhea, hyperandrogenism and the presence of ovarian cysts. It is also associated with infertility, obesity and insulin resistance. Mainly due to its heterogeneity, PCOS treatments are directed to manage its symptoms and to prevent associated diseases. The correct formation and regression of blood vessels during each ovarian cycle is indispensable for proper follicular development, ovulation and corpus luteum formation. The importance of these processes opened a new and promising field: ovarian angiogenesis. Vascular alterations characterize numerous pathologies, either with increased, decreased or abnormal angiogenesis. In the last years, several anomalies of ovarian angiogenesis have been described in women with PCOS. Therefore, it has been suggested that these alterations may be associated with the decreased - or lack of - ovulation rates and for the formation of cysts in the PCOS ovaries. Restoration of a proper vessel formation in the ovaries may lead to improved follicular development and ovulation in these patients. In the present review, we attempt to summarize the alterations in ovarian angiogenesis that have been described in women with PCOS. We also discuss the therapeutic approaches aimed to correct these alterations and their beneficial effects on the treatment of infertility in PCOS.

Effects of vitrification and transplantation on follicular development and expression of EphrinB1 and PDGFA in mouse ovaries

The aim of this study was to assess the follicular development and the patterns of EphrinB1 and PDGFA immunostaining in vitrified mouse ovarian tissue (OT) with and without transplantation. Histological evaluation was performed on fresh and vitrified OTs, whether transplanted or not. RT-PCR was performed on fresh and vitrified ovarian samples (OSs) and vitrified OS graft. Vitrification alone did not significantly reduce the normal primordial, primary, and secondary follicles except antral ones (p > 0.05). However, transplantation decreased all the follicle types. The EphrinB1 immunoexpression showed high intensity in all follicular types in vitrified OT and the significant increased was detected in secondary and antral follicles (p < 0.05). PDGFA protein immunoexpression of primordial and primary follicles was decreased in vitrified OT (p < 0.05). However, the lowest immunoexpression of EphrinB1 and PDGFA was detected after transplantation (p < 0.05). The levels of ephrinb1 and pdgfa mRNA expressions in vitrified OS and vitrified OS grafts were found as comparable to the fresh OS. In conclusion, vitrification has no detrimental effect on the follicles at the different developmental stages, majority of ovarian follicular loss takes place after transplantation rather than vitrification. Overall, vitrification and grafting do not change the ephrinb1 and pdgfa gene expressions. In addition, EphrinB1 and PDGFA are expressed during different stages of folliculogenesis in a different manner in fresh, vitrified, or grafted OTs. Vitrification and/or grafting appear to affect the follicular expression of EphrinB1 and PDGFA. These findings suggest that these proteins could have several functions related to the development of follicles and angiogenesis after transplantation.

Fertility Preservation in Cancer Patients: In Vivo and In Vitro Options

Oocyte, embryo and ovarian tissue cryopreservation are being increasingly proposed for fertility preservation among cancer patients undergoing therapy to enable them to have babies after the cancer is cured. Embryo cryopreservation is not appropriate for single girls without any sperm partner and also because oocyte retrieval is an extended procedure, it is impossible in cases requiring immediate cancer cure. Thus ovarian tissue cryopreservation has been suggested for fertility preservation especial in cancer patients. The main goal of ovarian cryopreservation is re-implanting the tissue into the body to restore fertility and the hormonal cycle. Different cryopreservation protocols have been examined and established for vitrification of biological samples. We have used Cryopin to plunge ovarian tissue into the liquid nitrogen and promising results have been observed. Ovarian tissue re-implantation after cancer cure has one problem- the possibility of recurrence of malignancy in the reimplanted tissue is high. Xenografting-implantation of the preserved tissue in another species- also has its drawbacks such as molecular signaling from the recipient. In vitro follicle culturing is a safer method to obtain mature oocytes for fertilization and the various studies that have been carried out in this area are reviewed in this paper.

Genomic analysis of stayability in Nellore cattle

Stayability, which can be defined as the probability of a cow calving at a certain age when given the opportunity, is an important reproductive trait in beef cattle because it is directly related to herd profitability. The objective of this study was to estimate genetic parameters and to identify possible genomic regions associated with the phenotypic expression of stayability in Nellore cows. The variance components were estimated by Bayesian inference using a threshold animal model that included the systematic effects of contemporary group and sexual precocity and the random effects of animal and residual. The SNP effects were estimated by the single-step genomic BLUP method using information of 2,838 animals (2,020 females and 930 sires) genotyped with the Illumina High-Density BeadChip Array (San Diego, CA, USA). The variance explained by windows formed by 200 consecutive SNPs was used to identify genomic regions of largest effect on the expression of stayability. The heritability was 0.11 ± 0.01 when A matrix (pedigree) was used and 0.14 ± 0.01 when H matrix (relationship matrix that combines pedigree information and SNP data) was used. A total of 147 candidate genes for stayability were identified on chromosomes 1, 2, 5, 6, 9 and 20 and on the X chromosome. New candidate regions for stayability were detected, most of them related to reproductive, immunological and central nervous system functions.

Ovarian Folliculogenesis

The ovary, the female gonad, serves as the source for the germ cells as well as the major supplier of steroid sex hormones. During embryonic development, the primordial germ cells (PGCs) are specified, migrate to the site of the future gonad, and proliferate, forming structures of germ cells nests, which will eventually break down to generate the primordial follicles (PMFs). Each PMF contains an oocyte arrested at the first prophase of meiosis, surrounded by a flattened layer of somatic pre-granulosa cells. Most of the PMFs are kept dormant and only a selected population is activated to join the growing pool of follicles in a process regulated by both intra- and extra-oocyte factors. The PMFs will further develop into secondary pre-antral follicles, a stage which depends on bidirectional communication between the oocyte and the surrounding somatic cells. Many of the signaling molecules involved in this dialog belong to the transforming growth factor β (TGF-β) superfamily. As the follicle continues to develop, a cavity called antrum is formed. The resulting antral follicles relay on the pituitary gonadotropins, follicle-stimulating hormone (FSH), and luteinizing hormone (LH) for their development. Most of the follicles undergo atretic degeneration and only a subset of the antral follicles, known as the dominant follicles, will reach the preovulatory stage at each reproductive cycle, respond to LH, and subsequently ovulate, releasing a fertilizable oocyte. The remaining somatic cells in the raptured follicle will undergo terminal differentiation and form the corpus luteum, which secretes progesterone necessary to maintain pregnancy.

Local administration of platelet-derived growth factor B (PDGFB) improves follicular development and ovarian angiogenesis in a rat model of Polycystic Ovary Syndrome

Alterations in ovarian angiogenesis are common features in Polycystic Ovary Syndrome (PCOS) patients; the most studied of these alterations is the increase in vascular endothelial growth factor (VEGF) production by ovarian cells. Platelet-derived growth factor B (PDGFB) and D (PDGFD) are decreased in follicular fluid of PCOS patients and in the ovaries of a rat model of PCOS. In the present study, we aimed to analyze the effects of local administration of PDGFB on ovarian angiogenesis, follicular development and ovulation in a DHEA-induced PCOS rat model. Ovarian PDGFB administration to PCOS rats partially restored follicular development, decreased the percentage of cysts, increased the percentage of corpora lutea, and decreased the production of anti-Müllerian hormone. In addition, PDGFB administration improved ovarian angiogenesis by reversing the increase in periendothelial cell area and restoring VEGF levels. Our results shed light into the mechanisms that lead to altered ovarian function in PCOS and provide new data for potential therapeutic strategies.

Infertility risk and teratogenicity of molecularly targeted anticancer therapy: A challenging issue

The growing population of young cancer survivors and a trend toward postponing pregnancy until later in life are shifting areas of focus toward understanding treatment induced sequelae, particularly the effects of cancer and/or treatment on fertility. Whereas the fertility risk of cytotoxic agents for both men and women is well-recognized, the fertility risks and teratogenic potential associated with molecular targeted therapies are not established. We summarize available preclinical and clinical data on the impact of new molecular targeted agents on fertility in both sexes, and their potential teratogenic effects, providing recommendations for clinicians, where possible. Agents were categorized by class and the potential relevance of their target signaling pathways to gonadal maturation discussed.

Gonadotoxic Effects of Nilotinib in Chronic Myeloid Leukemia Treatment Dose in a Mouse Model

Objective:

Tyrosine kinase inhibitors may have deleterious effects on spermatogenesis or folliculogenesis, resulting in male or female subfertility. The aim of this study is to determine the effect of nilotinib, which is used routinely to treat chronic myeloid leukemia, on spermatogenesis and folliculogenesis by using histopathological parameters.

Materials and Methods:

Ten male and ten female mice were orally treated with nilotinib at 20 mg/kg body weight dissolved in drinking water daily for 2 months.

Results:

When compared with the control group, a statistically significant decrease was demonstrated in the total follicle numbers of the female mice in the nilotinib group (268±110 vs. 170±60; p=0.03). Active spermatogenesis was observed in each tubule sample taken from the mice in the control and nilotinib groups. Spermatogenic activity was similar in the two groups.

Conclusion:

We have demonstrated that even though spermatogenesis is preserved, folliculogenesis is inhibited by the usage of a continuous nilotinib treatment dose in chronic myeloid leukemia.

The Tyrosine Kinase Inhibitor Sunitinib Affects Ovulation but Not Ovarian Reserve in Mouse: A Preclinical Study

The aim of the study was to evaluate ovarian toxicity of tyrosine kinase inhibitor (TKI) sunitinib, since only scarce data are available on gonadal function after this treatment. Six-week-old female mice received orally, once daily, vehicle or sunitinib (50 mg/kg/d) during 5 weeks. Fertility parameters were analyzed from ovulation to litter assessment. Sunitinib exposure significantly reduced (i) corpora lutea number per ovary (1.1 ± 0.38 in sunitinib group versus 4 ± 0.79 in control group, p<0.01) and (ii) serum Anti Müllerian hormone (AMH) levels in sunitinib treated mice (12.01 ± 1.16) compared to control mice (14.33 ± 0.87 ng/ml, p< 0.05). However, primordial and growing follicles numbers per ovary were not different in both groups. After treatment withdrawal, female mice in both groups were able to obtain litters. These data could be helpful to counsel clinicians and patients, when fertility preservation methods are discussed, before TKI treatment in girls and young women.

Control of Oocyte Growth and Development by Intercellular Communication Within the Follicular Niche

In the mammalian ovary, each oocyte grows and develops within its own structural and developmental niche-the follicle. Together with the female germ cell in the follicle are somatic granulosa cells, specialized companion cells that surround the oocyte and provide support to it, and an outer layer of thecal cells that serve crucial roles including steroid synthesis. These follicular compartments function as a single physiological unit whose purpose is to produce a healthy egg, which upon ovulation can be fertilized and give rise to a healthy embryo, thus enabling the female germ cell to fulfill its reproductive potential. Beginning from the initial stage of follicle formation and until terminal differentiation at ovulation, oocyte and follicle growth depend absolutely on cooperation between the different cellular compartments. This cooperation synchronizes the initiation of oocyte growth with follicle activation. During growth, it enables metabolic support for the follicle-enclosed oocyte and allows the follicle to fulfill its steroidogenic potential. Near the end of the growth period, intra-follicular interactions prevent the precocious meiotic resumption of the oocyte and ensure its nuclear differentiation. Finally, cooperation enables the events of ovulation, including meiotic maturation of the oocyte and expansion of the cumulus granulosa cells. In this chapter, we discuss the cellular interactions that enable the growing follicle to produce a healthy oocyte, focusing on the communication between the germ cell and the surrounding granulosa cells.

Inhibition of platelet-derived growth factor (PDGF) receptor affects follicular development and ovarian proliferation, apoptosis and angiogenesis in prepubertal eCG-treated rats

The platelet-derived growth factor (PDGF) system is crucial for blood vessel stability. In the present study, we evaluated whether PDGFs play a critical intraovarian survival role in gonadotropin-dependent folliculogenesis. We examined the effect of intrabursal administration of a selective platelet-derived growth factor receptor (PDGFR) inhibitor (AG1295) on follicular development, proliferation, apoptosis and blood vessel formation and stability in ovaries from rats treated with equine chorionic gonadotropin (eCG). The percentages of preantral follicles (PAFs) and early antral follicles (EAFs) were lower in AG1295-treated ovaries than in control ovaries (p < 0.01-0.05). The percentage of atretic follicles (AtrFs) increased in AG1295-treated ovaries compared to control (p < 0.05). The ovarian weight and estradiol concentrations were lower in AG1295-treated ovaries than in the control group (p < 0.01 and p < 0.05, respectively), whereas progesterone concentrations did not change. AG1295 decreased the proliferation index in EAFs (p < 0.05) and increased the percentage of nuclei positive for cleaved caspase-3 and apoptotic DNA fragmentation (p < 0.01-0.05). AG1295 increased the expression of Bax (p < 0.05) without changes in the expression of Bcl-2 protein. AG1295-treated ovaries increased the cleavage of caspase-8 (p < 0.05) and decreased AKT and BAD phosphorylation compared with control ovaries (p < 0.05). AG1295 caused a decrease not only in the endothelial cell area but also in the area of pericytes and vascular smooth muscle cells (VSMCs) in the ovary (p < 0.05). Our findings suggest that the local inhibition of PDGFs causes an increase in ovarian apoptosis through an imbalance in the ratio of antiapoptotic to proapoptotic proteins, thus leading a larger number of follicles to atresia. PDGFs could exert their mechanism of action through an autocrine/paracrine effect on granulosa and theca cells mediated by PDGFRs. In conclusion, these data clearly indicate that the PDGF system is necessary for follicular development induced by gonadotropins.

Isolation and culture of chicken primordial follicles

The establishment of a primordial follicle culture system is important for the study of follicular development. Hence, the objective of this study was to isolate chicken primordial follicles and establish culture methods. Ovaries from 2-wk-old chickens were treated with trypsin-EDTA, collagenase II, or collagenase type IA, along with a mechanical isolation technique. Isolated follicles were cultured under different conditions. Results showed a significant difference in the follicular recovery and survival rates among different enzymes and methods used. The maximal follicular yield was obtained by trypsin+EDTA and collagenase II digestion, followed by collagenase type IA digestion. However, the highest follicular viability rate was observed in groups of collagenase type IA digestion and the mechanical isolation method. Enzymatic treatment resulted in higher misshapen oocytes or follicles, though the diameters of the follicles were not significantly changed. In addition, our follicle culture results for different conditions showed maximal survival rates of primordial follicles in alginate hydrogel beads after 12 d of culture. Thus, we successfully established methods for isolating and culturing chicken primordial follicles. The present method will greatly facilitate investigation of the regulation of follicular development.

Cellular and molecular regulation of the activation of mammalian primordial follicles: somatic cells initiate follicle activation in adulthood

BACKGROUND

The first small follicles to appear in the mammalian ovaries are primordial follicles. The initial pool of primordial follicles serves as the source of developing follicles and oocytes for the entire reproductive lifespan of the animal. Although the selective activation of primordial follicles is critical for female fertility, its underlying mechanisms have remained poorly understood.

METHODS

A search of PubMed was conducted to identify peer-reviewed literature pertinent to the study of mammalian primordial follicle activation, especially recent reports of the role of primordial follicle granulosa cells (pfGCs) in regulating this process.

RESULTS

In recent years, molecular mechanisms that regulate the activation of primordial follicles have been elucidated, mostly through the use of genetically modified mouse models. Several molecules and pathways operating in both the somatic pfGCs and oocytes, such as the phosphatidylinositol 3 kinase (PI3K) and the mechanistic target of rapamycin complex 1 (mTORC1) pathways, have been shown to be important for primordial follicle activation. More importantly, recent studies have provided an updated view of how exactly signaling pathways in pfGCs and in oocytes, such as the KIT ligand (KL) and KIT, coordinate in adult ovaries so that the activation of primordial follicles is achieved.

CONCLUSIONS

In this review, we have provided an updated picture of how mammalian primordial follicles are activated. The functional roles of pfGCs in governing the activation of primordial follicles in adulthood are highlighted. The in-depth understanding of the cellular and molecular mechanisms of primordial follicle activation will hopefully lead to more treatments of female infertility, and the current progress indicates that the use of existing primordial follicles as a source for obtaining fertilizable oocytes as a new treatment for female infertility is just around the corner.