Analysis of VEGF gene polymorphisms and serum VEGF protein levels contribution in polycystic ovary syndrome of patients

Vascular endothelial growth factor I/D variant and postmenopausal osteoporosis risk in the Turkish population

INTRODUCTION

Postmenopausal osteoporosis (PMOP) is a common metabolic bone disorder manifested by low bone mineral density and increased fracture risks in postmenopausal women. Vascular endothelial growth factor (VEGF) has been shown to play an important role in bone formation. In this study, we investigated the potential association between the VEGF insertion/deletion (I/D) variant (rs35569394) and PMOP in a cohort of postmenopausal Turkish women.

METHODS

This study included 300 women, including 150 PMOP patients and 150 healthy postmenopausal women. A T score was used in the diagnosis of OP. DNA was extracted from all subjects. The VEGF I/D polymorphism was analyzed by the PCR method. The Hardy-Weinberg equilibrium (HWE) test and odds ratio (OR) were analyzed, considering CI 95% and p ≤ 0.05.

RESULTS

The mean age of patients aged between 40 and 74 was 60.32 ± 8.65. The frequency of the I/I, I/D, and D/D genotypes was 7.34% versus 6.66%; 67.33% versus 65.34%; and 25.33% versus 28%, in patients and the control group, respectively. The allele frequencies were I: 41% (patients) and 39.4% (controls); D: 59% (patients) and 60.66% (controls). There was no statistically significant difference in the VEGF - 2549 I/D allele and genotype distribution between patients with PMOP and control subjects (p = 0.349, p = 0.864, respectively).

CONCLUSION

Our results showed that the VEGF I/D variant was not a significant factor in the development of PMOP in a Turkish population sample. These findings need confirmation in other ethnic populations.

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.

Two cases of polycystic ovary syndrome with onset of severe ovarian hyperstimulation syndrome following controlled ovarian stimulation with aromatase inhibitors for fertility preservation before breast cancer treatment

OBJECTIVE

The risks of ovarian hyperstimulation syndrome (OHSS) involve high estrogen (E₂) levels. We report two breast cancer patients with polycystic ovarian syndrome who underwent fertility preservation and had severe OHSS; their E₂ levels were lowered using aromatase inhibitors (AI).

CASE REPORTS

A 36-year-old woman underwent controlled ovarian stimulation (COS) with AI and cryopreserved 10 blastocysts. She was hospitalized with OHSS (E₂ = 139.1 pg/mL). She improved with infusion alone. A 31-year-old woman underwent COS with AI and cryopreserved 8 blastocysts. She was hospitalized for OHSS (E₂: 429 pg/mL). Her vascular endothelial growth factor (VEGF) levels were high (62 pg/mL) at 8 days after the procedure. She needed hospitalization for 9 days. The planned adjuvant therapy was delayed for a week in both cases.

CONCLUSION

Elevated VEGF levels should be considered as a risk factor of OHSS even if E₂ levels are low with AI treatment.

Explore the potential molecular mechanism of polycystic ovarian syndrome by protein-protein interaction network analysis

Polycystic ovary syndrome (PCOS) is one of the most common endocrine disorders prevailing in reproductive age women, present in 3-15% population of women worldwide. Although there are many studies on PCOS, its underlying mechanism remains to be determined. The present study was to construct protein-protein interaction networks based on the potential disease-causing genes for PCOS and characterize the underlying molecular mechanisms of PCOS using the networks. PCOS-associated genes were extracted from DisGeNet and the protein-protein interaction networks (PPIN) of PCOS were constructed using the String Database. Then we utilized MCODE algorithm to analyse the hub-gene modules from the PPIN. Finally, the major biological functions and signaling pathways involved in the hub modules were explored by functional enrichment analysis. A total of 522 candidate genes associated to PCOS were extracted from DisGeNET database. The PPIN constructed using the genes we have collected above included 488 genes and 2767 interaction relationships. Moreover, seven major gene modules were obtained after analyzing the PPIN with the use of MCODE plug-in. The major modules generated were enriched in certain biological functions such as cancer and cell proliferation and apoptosis, regulation of lipid and glucose metabolism, cell cycle and so on. The integrated analysis performed in the current study revealed that these hub modules and their related genes are closely associated to the pathogenesis of PCOS, which may probably provide novel insights for the treatment of PCOS and the study of its latent pathogenic mechanism. The relationship between several of the key genes including ALB, TOP2A, PTGER3, NPB and BRD2 in the modules and PCOS has not been investigated previously and it remains to be verified by further research of large sample, multi-center and multi-ethnic.

A Narrative Review of Current Understanding of the Pathophysiology of Polycystic Ovary Syndrome: Focus on Plausible Relevance of Vitamin D

Polycystic ovarian syndrome (PCOS) is the most prevalent endocrinopathy of reproductive years. Salient features in presentation of patients PCOS include menstrual dysfunction, hyperandrogenism and/or polycystic appearance of ovaries on ultrasound. While the diagnosis of PCOS depends on presence of specified criteria, misdiagnoses are common. Despite years of extensive research, the exact aetiology of PCOS remains largely unknown. In the past decade, apart from insulin resistance and hyperandrogenemia, anti-mullerian hormone (AMH), an important marker of ovarian reserve, and vascular endothelial growth factor (VEGF), a crucial factor in angiogenesis, have been examined as plausible players of causative relevance for PCOS. Vitamin D, a sex-steroid hormone that is universally known for its relevance for skeletal health, has received increasing attention due to growing evidence supporting its pivotal in reproductive physiology and in PCOS. In this review we summarize our current understanding of the mechanisms relevant to the pathophysiology of PCOS and examine the role of vitamin D signalling in this context.

Polymorphisms of vascular endothelial growth factor and recurrent implantation failure: a systematic review and meta-analysis

PURPOSE

To investigate the associations between polymorphisms of vascular endothelial growth factor (VEGF) with recurrent implantation failure (RIF).

METHODS

We performed the systematic review and meta-analysis by searching databases of PubMed, EMBASE, OVID, and CNKI (China National Knowledge Infrastructure) for studies that evaluated the associations between VEGF polymorphisms with RIF. Meta-analysis was performed if the polymorphism was studied by more than two case-control studies. Data were analyzed using R software. Odds ratios (ORs) with 95% confidence intervals (CIs) were reported to assess the associations.

RESULTS

Nine VEGF polymorphisms (-1154G > A, -460T > C, +405G > C, -7C > T, -634C > G, -2578C > A, +936C > T, 5C > T, -583C > T) were systematically reviewed. Meta-analysis was performed on VEGF -1154 G > A polymorphism. Three case-control studies consisted of 683 women were included in the quantitative meta-analysis (305 RIF patients and 378 controls). Results showed that VEGF -1154A allele was significantly associated with RIF (OR 1.39, 95% CI 1.08-1.78, P-value = 0.01). The dominant genetic model showed that VEGF 1154AA plus VEGF 1154AG genotypes were more frequent in RIF patients than VEGF 1154GG genotype (OR 1.56, 95% CI 1.10-2.20, P-value = 0.01). However, the result under the recessive genetic model showed no significant difference (OR 1.67, 95% CI 0.92-3.03, P-value = 0.09).

CONCLUSION

VEGF -1154A allele may serve as one of the predisposing factors of RIF. Women with VEGF 1154 AA/GA genotypes were at higher risk of RIF. However, we should consider the haplotype effect of VEGF polymorphisms in future studies.

Variations in the Profiles of Vascular-Related Factors Among Different Sub-Types of Polycystic Ovarian Syndrome in Northern China

Recently, a growing body of evidence has suggested that abnormal ovarian angiogenesis, secondary to the imbalance between various angiogenic markers, is involved in the pathogenesis of PCOS, and this has led to the use of various interventions (such as Diane-35) to restore the normal ovarian angiogenesis. Therefore, we conducted the current investigation to determine the role of such markers (endothelial growth factor (VEGF), endostatin (ES), and thrombospondin-1 (TSP-1)) in the pathogenesis of PCOS along with the associated changes in ovarian blood flow in patients with PCOS compared to healthy controls, both before and after a course of oral contraception. A total of 381 patients with PCOS and 98 healthy females of childbearing age were recruited from July 2014 to June 2017 at the Reproductive Center of the Second Affiliated Hospital of Harbin Medical University. The serum levels of VEGF, ES, and TSP-1 were determined by enzyme-linked immunosorbent assay, while ovarian perfusion was measured by the pulsatility index (PI) and resistance index (RI) by using transvaginal color Doppler ultrasound. Repeated analyses were carried out after 3 months of Diane-35 treatment. Post-treatment serum levels of luteinizing hormone (LH)/follicle stimulating hormone (FSH) ratio of patients with PCOS decreased significantly (P <0.05). The RI values of most PCOS patients increased after treatment (P<0.05), while PI was significantly increased in all patients (P<0.05). However, variable changes in the serum levels of TSP-1, VEGF, and ES after treatment were observed. Serum VEGF levels showed a negative correlation with serum LH/FSH ratio, T concentration, and ES (P <0.05), while ES levels were negatively correlated with serum T concentrations only (P<0.05). The markers of angiogenesis (VEGF, ES, and TSP-1) were expressed differently among PCOS patients, who also responded differently to the same course of Diane-35 treatment. This field still warrants further investigation to reach a more definitive conclusion.

VEGF gene rs35569394 polymorphism in patients with Polycystic Ovary Syndrome

OBJECTIVE

The relationship between the clinicopathological and sociodemographics characteristics of acral melanomas diagnosed at BACKGROUND: This study aimed to investigate the frequency of VEGF gene insertion (I) / deletion (D) polymorphism (rs35569394) in patients with Polycystic Ovarian Syndrome (PCOS) and to compare with a control population to verify its association with the pathology.

METHODS

206 women participated in this study, 103 with PCOS (group of patients) and 103 without the disease (control group). After extraction of genomic DNA from the samples, molecular analysis was performed by Polymerase Chain Reaction (PCR) and electrophoresis in polycrylamide. Descriptive analysis, univariate analysis and logistic regression model were used. Results were presented in odds ratio (OR) and 95% confidence interval (95% CI), considering the significance of p <0.05.

RESULTS

There were no statistical differences between patients and controls for allele frequencies (χ2 = 1.16, p = 0.56). The genotypic frequency distribution was in Hardy Weinberg equilibrium for the patients (χ2 = 2.42; p <0.05), but not for the control group (χ2 = 7.26; p <0.05). Regarding risk factors for the syndrome, a history of familial PCOS is more frequent among women with the syndrome.

CONCLUSIONS

In the present study, there is no association between VEGF gene I / D polymorphism and PCOS.

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

BACKGROUND

Polycystic ovarian syndrome (PCOS) is a multi-gene hereditary disorder caused by the interaction of certain gene variation with environmental factors. Previous studies have shown that vascular endothelial growth factor (VEGF) gene polymorphisms are associated with the risk of polycystic ovarian syndrome. However, the results of these studies remain controversial. We performed the present meta-analysis aiming to further investigate the potential relationship between VEGF polymorphisms and susceptibility to PCOS.

METHODS

The following databases were systematically searched: PubMed, EMBASE, Web of Science (WOS), China National Knowledge Infrastructure (CNKI), and Wanfang Databases. The correlation between VEGF polymorphisms and PCOS risk was assessed by calculating pooled odds ratios (ORs) and their 95% confidence intervals (95% CIs). Subgroup analyses stratified by ethnicity and source of control were also conducted. Besides, trial sequential analysis (TSA) was done to verify the reliability of the pooled results.

RESULTS

10 relevant case-control studies were incorporated in this meta-analysis, involving 1347 PCOS cases and 1378 controls. The VEGF rs2010963 polymorphism was associated with decreased PCOS risk in the whole population and the Asian populations. The VEGF rs3025039 polymorphism was associated with decreased PCOS susceptibility and the Asian populations, but increased risk of PCOS was observed among the Caucasian populations. In addition, the results of trial sequential analysis (TSA) showed the negative correlation between rs2010963 and PCOS risk, obtained by our meta-analysis, was stable and reliable.

CONCLUSION

Overall, different VEGF gene polymorphisms may exert different effects on PCOS susceptibility. The VEGF rs2010963 polymorphism decreases PCOS susceptibility in both the whole population and the Asian populations, and VEGF rs3025039 polymorphism causes lower PCOS susceptibility in the whole population and the Asian populations but higher in the Caucasian populations.

microRNA Expression in Women With and Without Polycystic Ovarian Syndrome Matched for Body Mass Index

Background: Despite several authors who have hypothesized that alterations of small noncoding RNAs (miR) are implicated in the etiopathogenesis of polycystic ovarian syndrome (PCOS), contrasting findings have been reported so far. Discrepancies in body mass index (BMI) levels may account for these differences; therefore, the aim of the present study was to determine whether miR differed in serum samples collected from age- and BMI-matched control and PCOS women. Methods: In a cross-sectional study, miR were measured using quantitative polymerase chain reaction in 29 women with anovulatory PCOS women and 29 control women who were in the follicular phase of their menstrual cycle, from the local biobank. Results: One hundred seventy-six miR were detected, of which 15 miR passed the false discovery rate (FDR; p < 0.05) that differed between PCOS and control women. There was no association of the top 9 miR (p < 0.02) (miR-486-5p, miR-24-3p, miR-19b-3p, miR-22-3p, miR-19a-3p, miR-339-5p, miR-185-5p, miR-101-3p, miR-let-7i-5p) with BMI, androgen levels, insulin resistance, or antimullerian hormone (AMH) in either PCOS or normal women. Ingenuity pathway assessment showed the pathways were interrelated for abnormalities of the reproductive system. Conclusion: When the confounding influence of weight was accounted for, miR levels differed between anovulatory PCOS women and control women in the follicular phase of the menstrual cycle. Interestingly, the differing miR were associated with the pathways of reproductive abnormalities but did not associate with AMH or metabolic parameters.