Association of vascular endothelial growth factor polymorphisms with polycystic ovarian syndrome risk: a meta-analysis

Ameliorative potential of rosmarinic acid in a rat model of polycystic ovary syndrome: Targeting MCP-1 and VEGF: A histological, immunohistochemical, and biochemical study

Polycystic ovary syndrome (PCOS) is a multidisciplinary endocrinopathy that affects women of reproductive age. It is characterized by menstrual complications, hyperandrogenism, insulin resistance, and cardiovascular issues. The current research investigated the efficacy of rosmarinic acid in letrozole-induced PCOS in adult female rats as well as the potential underlying molecular mechanisms. Forty female rats were divided into the control group, the rosmarinic acid group (50 mg/kg per orally, po) for 21 days, PCOS group; PCOS was induced by administration of letrozole (1 mg/kg po) for 21 days, and rosmarinic acid-PCOS group, received rosmarinic acid after PCOS induction. PCOS resulted in a marked elevation in both serum luteinizing hormone (LH) and testosterone levels and LH/follicle-stimulating hormone ratio with a marked reduction in serum estradiol and progesterone levels. A marked rise in tumor necrosis factor-α (TNF-α), interleukin-1β, monocyte chemotactic protein-1, and vascular endothelial growth factor (messenger RNA) in the ovarian tissue was reported. The histological analysis displayed multiple cystic follicles in the ovarian cortex with markedly thin granulosa cell layer, vacuolated granulosa and theca cell layers, and desquamated granulosa cells. Upregulation in the immune expression of TNF-α and caspase-3 was demonstrated in the ovarian cortex. Interestingly, rosmarinic acid ameliorated the biochemical and histopathological changes. In conclusion, rosmarinic acid ameliorates letrozole-induced PCOS through its anti-inflammatory and antiangiogenesis effects.

Biomechanical forces and signals operating in the ovary during folliculogenesis and their dysregulation: implications for fertility

BACKGROUND

Folliculogenesis occurs in the highly dynamic environment of the ovary. Follicle cyclic recruitment, neo-angiogenesis, spatial displacement, follicle atresia and ovulation stand out as major events resulting from the interplay between mechanical forces and molecular signals. Morphological and functional changes to the growing follicle and to the surrounding tissue are required to produce oocytes capable of supporting preimplantation development to the blastocyst stage.

OBJECTIVE AND RATIONALE

This review will summarize the ovarian morphological and functional context that contributes to follicle recruitment, growth and ovulation, as well as to the acquisition of oocyte developmental competence. We will describe the changes occurring during folliculogenesis to the ovarian extracellular matrix (ECM) and to the vasculature, their influence on the mechanical properties of the ovarian tissue, and, in turn, their influence on the regulation of signal transduction. Also, we will outline how their dysregulation might be associated with pathologies such as polycystic ovary syndrome (PCOS), endometriosis or premature ovarian insufficiency (POI). Finally, for each of these three pathologies, we will highlight therapeutic strategies attempting to correct the altered biomechanical context in order to restore fertility.

SEARCH METHODS

For each area discussed, a systematic bibliographical search was performed, without temporal limits, using PubMed Central, Web of Science and Scopus search engines employing the keywords extracellular matrix, mechanobiology, biomechanics, vasculature, angiogenesis or signalling pathway in combination with: ovary, oogenesis, oocyte, folliculogenesis, ovarian follicle, theca, granulosa, cumulus, follicular fluid, corpus luteum, meiosis, oocyte developmental competence, preimplantation, polycystic ovary syndrome, premature ovarian insufficiency or endometriosis.

OUTCOMES

Through search engines queries, we yielded a total of 37 368 papers that were further selected based on our focus on mammals and, specifically, on rodents, bovine, equine, ovine, primates and human, and also were trimmed around each specific topic of the review. After the elimination of duplicates, this selection process resulted in 628 papers, of which 287 were cited in the manuscript. Among these, 89.2% were published in the past 22 years, while the remaining 8.0%, 2.4% or 0.3% were published during the 1990s, 1980s or before, respectively. During folliculogenesis, changes occur to the ovarian ECM composition and organization that, together with vasculature modelling around the growing follicle, are aimed to sustain its recruitment and growth, and the maturation of the enclosed oocyte. These events define the scenario in which mechanical forces are key to the regulation of cascades of molecular signals. Alterations to this context determine impaired folliculogenesis and decreased oocyte developmental potential, as observed in pathological conditions which are causes of infertility, such as PCOS, endometriosis or POI.

WIDER IMPLICATIONS

The knowledge of these mechanisms and the rules that govern them lay a sound basis to explain how follicles recruitment and growth are modulated, and stimulate insights to develop, in clinical practice, strategies to improve follicular recruitment and oocyte competence, particularly for pathologies like PCOS, endometriosis and POI.

Polymorphisms rs2010963 and rs833061 of the VEGF gene in polycystic ovary syndrome

OBJECTIVE:

The polycystic ovary syndrome is the most common endocrine disorder, characterized by the dysregulation of ovarian angiogenesis. This alteration can be related to changes in the activities of the vascular endothelial growth factor (VEGF) gene. Single-nucleotide polymorphisms have been observed in the promoter, intronic, and untranslated regions of the VEGF gene, and several studies have suggested that these polymorphisms may be associated with the risk of polycystic ovary syndrome. This study aimed to investigate the association between rs2010963 and rs833061 polymorphisms and haplotypes of VEGF in the etiology of polycystic ovary syndrome.

METHODS:

A total of 210 women, 102 diagnosed with polycystic ovary syndrome and 108 controls, participated in this study. The genotyping of the samples was performed by PCR-RFLP and real-time PCR for rs2010963 and rs833061 polymorphisms, respectively. The statistical analyses were performed by the chi-square test and logistic regression model.

RESULTS:

The clinical characteristics of the patients showed that 75.8% of the patients did not become pregnant, 36.3% had a family history of polycystic ovary syndrome, 58.6% were obese, and about 60% had clinical characteristics of hyperandrogenism. There were no associations between the distribution of rs2010963 (OR 1.24; 95%CI 0.60–2.57; p=0.56) and rs833061 (OR 0.78; 95%CI 0.32–1.92; p=0.59) in patients and controls.

CONCLUSIONS:

The patients with polycystic ovary syndrome have similar rates of VEGF polymorphisms rs2010963 and rs833061 on the general population.

Study of the Association between VEGF Polymorphisms and the Risk of Coronary Artery Disease in Koreans

Coronary artery disease (CAD), a leading cause of death worldwide, has a complex etiology comprising both traditional risk factors (type 2 diabetes, dyslipidemia, arterial hypertension, and cigarette smoking) and genetic factors. Vascular endothelial growth factor (VEGF) notably contributes to angiogenesis and endothelial homeostasis. However, little is known about the relationship between CAD and VEGF polymorphisms in Koreans. The aim of this study is to investigate the associations of 2 VEGF promoter region polymorphisms (−1154G>A [rs1570360], −1498T>C [rs833061]) and 4 VEGF 3′-UTR polymorphisms (+936C>T [rs3025039], +1451C>T [rs3025040], +1612G>A [rs10434], and +1725G>A [rs3025053]) with CAD susceptibility in Koreans. We studied 885 subjects: 463 CAD patients and 422 controls. Genotyping was conducted with polymerase chain reaction-restriction fragment length polymorphism analysis and TaqMan allelic discrimination assays, and the genotype frequencies were calculated. We then performed haplotype and genotype combination analyses and measured the associations between VEGF polymorphisms and clinical variables in both the CAD patients and control subjects. We detected statistically significant associations between CAD and certain VEGF allele combinations. In the haplotypes of 5 single-nucleotide polymorphisms, the VEGF allele combination −1154A/+936T was associated with a decreased prevalence of CAD (A-T-T-G-G of VEGF −1154G>A/−1498T>C/+936C>T/+1612G>A/+1725G>A, AOR = 0.077, p = 0.021). In contrast, the VEGF allele combinations −1498T/+1725A and −1498T/+1612A/+1725A were associated with an increased prevalence of CAD (G-T-C-C-A of VEGF −1154G>A/−1498T>C/+936C>T/+1451C>T/+1725G>A, AOR = 1.602, p = 0.047; T-C-C-A-A of VEGF −1498T>C/+936C>T/+1451C>T/+1612G>A/+1725G>A, AOR = 1.582, p = 0.045). Gene−environment combinatorial analysis showed that the combination of the VEGF +1725AA genotype and several clinical factors (e.g., body mass index, hemoglobin A1c, and low-density lipoprotein cholesterol) increased the risk of CAD. Therefore, we suggest that VEGF polymorphisms and clinical factors may impact CAD prevalence.

Research Progress of PCNA in Reproductive System Diseases

Reproductive system diseases have become a public health problem that endangers human physical and mental health. The causes of reproductive diseases are complex and diverse. From a biological point of view, abnormal cell proliferation may affect important physiological functions of reproductive organs and cause various gynecological or andrological diseases. Proliferating cell nuclear antigen (PCNA) is the most commonly used indicator for detecting cell proliferation activity. The up- or downregulation of its expression is of great significance in reproductive system diseases. This review summarizes the significance of the latest research on PCNA expression in reproductive system diseases.

Is fertility reduced in ovulatory women with polycystic ovary syndrome? An opinion paper

Polycystic ovary syndrome (PCOS) is the most common cause of anovulatory infertility; however, whether women with PCOS and spontaneous or drug-induced ovulatory cycles have the same reproductive potential as non-PCOS controls is a matter of debate. In the present opinion paper, the author takes the opportunity to summarize the collective evidence supporting the hypothesis of reduced fertility potential in women with PCOS, regardless of ovulatory status, and speculate that reduced reproductive potential may be caused by altered oocytes, embryo and endometrial competence, and infertility-related co-morbidities as well as an increased risk of pregnancy complications.

The protective effect of fenofibrate, triptorelin, and their combination against premature ovarian failure in rats

Cyclophosphamide (CP) is a chemotherapy alkylating agent that causes a lot of side effects including premature ovarian failure (POF). This study aimed to evaluate the possible protective effect of fenofibrate (FEN) in CP-induced POF. Rats were randomly divided into five groups as follows: negative control, CP, triptorelin (TRI)-treated, FEN (FEN)-treated, and FEN + TRI-treated. Histological study, collagen area fraction, and immunoexpression of proliferating cell nuclear antigen (PCNA) were evaluated. Also, estrogen, anti-mullerian hormone (AMH), follicle-stimulating hormone (FSH), luteinizing hormone (LH) and ovarian malondialdehyde (MDA), nitric oxide (NOx), reduced glutathione (GSH), superoxide dismutase (SOD), interleukin-10 (IL-10), tumor necrosis factor-alpha (TNF-α), and vascular endothelial growth factor (VEGF) were measured. CP significantly reduced ovarian follicle count, as compared with the control group (1.00 ± 0.76 versus 7.75 ± 1.83, respectively). Meanwhile, FEN, either solely or in combination with TRI, significantly increased ovarian follicle count, as compared with the CP group (3.88 ± 0.83 and 5.75 ± 1.39, respectively). As compared with the control group, CP increased the levels of MDA, NOx, IL-10, TNF-α, FSH, LH, and collagen area fraction; however, levels of GSH, SOD, VEGF, AMH, estrogen, and PCNA immunoexpression were reduced with CP. Administration of FEN either solely or in combination with TRI showed significant improvement in all the parameters previously mentioned. FEN can protect the ovary from CP-induced side effects possibly through antioxidant and anti-inflammatory actions.

Endometrial function in women with polycystic ovary syndrome: a comprehensive review

BACKGROUND

Polycystic ovary syndrome (PCOS) is the most common cause of anovulatory infertility. An endometrial component has been suggested to contribute to subfertility and poor reproductive outcomes in affected women.

OBJECTIVE AND RATIONALE

The aim of this review was to determine whether there is sufficient evidence to support that endometrial function is altered in women with PCOS, whether clinical features of PCOS affect the endometrium, and whether there are evidence-based interventions to improve endometrial dysfunction in PCOS women.

SEARCH METHODS

An extensive literature search was performed from 1970 up to July 2020 using PubMed and Web of Science without language restriction. The search included all titles and abstracts assessing a relationship between PCOS and endometrial function, the role played by clinical and biochemical/hormonal factors related to PCOS and endometrial function, and the potential interventions aimed to improve endometrial function in women with PCOS. All published papers were included if considered relevant. Studies having a specific topic/hypothesis regarding endometrial cancer/hyperplasia in women with PCOS were excluded from the analysis.

OUTCOMES

Experimental and clinical data suggest that the endometrium differs in women with PCOS when compared to healthy controls. Clinical characteristics related to the syndrome, alone and/or in combination, may contribute to dysregulation of endometrial expression of sex hormone receptors and co-receptors, increase endometrial insulin-resistance with impaired glucose transport and utilization, and result in chronic low-grade inflammation, immune dysfunction, altered uterine vascularity, abnormal endometrial gene expression and cellular abnormalities in women with PCOS. Among several interventions to improve endometrial function in women with PCOS, to date, only lifestyle modification, metformin and bariatric surgery have the highest scientific evidence for clinical benefit.

WIDER IMPLICATIONS

Endometrial dysfunction and abnormal trophoblast invasion and placentation in PCOS women can predispose to miscarriage and pregnancy complications. Thus, patients and their health care providers should advise about these risks. Although currently no intervention can be universally recommended to reverse endometrial dysfunction in PCOS women, lifestyle modifications and metformin may improve underlying endometrial dysfunction and pregnancy outcomes in obese and/or insulin resistant patients. Bariatric surgery has shown its efficacy in severely obese PCOS patients, but a careful evaluation of the benefit/risk ratio is warranted. Large scale randomized controlled clinical trials should address these possibilities.