Gene expression analysis of VEGF and its receptors and assessment of its serum level in unexplained recurrent spontaneous abortion

Biochemical markers for prediction of the first half pregnancy losses: a review

Objective

26% of all pregnancies end in miscarriage, and up to 10% of clinically diagnosed pregnancies, and recurrent pregnancy loss is 5% among couples of childbearing ages. Although there are several known causes of pregnancy loss in the first half, including recurrent pregnancy loss, including parental chromosomal abnormalities, uterine malformations, endocrinological disorders, and immunological abnormalities, about half of the cases of pregnancy loss in its first half remain unexplained.

Methods

The review includes observational controlled studies (case-control or cohort, longitudinal studies, reviews, meta-analyses), which include the study of biochemical factors for predicting pregnancy losses in the first half, in singlet pregnancy. The Newcastle-Ottawa Scale (NOS) was used to assess the research quality.

Results

Finally, 27 studies were included in the review, which has 134904 examined patients. The results of the review include estimates of β-human chorionic gonadotropin, progesterone, pregnancy-associated protein - A, angiogenic vascular factors, estradiol, α-fetoprotein, homocysteine and CA-125 as a predictors or markers of the first half pregnancy losses.

Conclusion

It may be concluded that to date, research data indicate the unavailability of any reliable biochemical marker for predicting pregnancy losses in its first half and require either a combination of them or comparison with clinical evidence. A fairly new model shall be considered for the assessment of α-fetoprotein in vaginal blood, which may have great prospects in predicting spontaneous miscarriages.

Are Altered Expression of Vascular Endothelial Growth Factor and Placental Growth Factor Associated with Placental Angiogenesis in Recurrent Pregnancy Loss?

Angiogenesis is one of the most important steps during pregnancy for placental and fetal development. Based on the hypothesis that vascular insufficiency and altered angiogenesis may lead to early pregnancy loss, the present study was aimed to understand the role of Vascular endothelial growth factor (VEGFA) and Placental growth factor (PLGF) gene expression in placental angiogenesis in the pathogenesis of Recurrent pregnancy loss (RPL). Gene expression analysis of VEGFA and PLGF was carried out in the placental tissue collected from 30 women with recurrent pregnancy loss and compared with the placenta obtained from 16 women with medically terminated pregnancy. The mRNA expression of both VEGFA and PLGF genes were significantly downregulated in the placenta of recurrent pregnancy loss in comparison to the placenta of medically terminated pregnancies. In conclusion the results of the present study suggest that altered expression of VEGFA and PLGF genes in placenta disturb the angiogenesis and contribute to the pathogenesis of recurrent pregnancy loss.

Endometrial scratching in unexplained repeated implantation failure causes two competing forces, angiogenesis and anti-angiogenesis: An RCT study

Background

A significant association between endometrial vascularity and pregnancy has been shown in previous research, while poor vascularization was attributed to repeated implantation failure (RIF). One possible approach to enhance angiogenesis for successful implantation is endometrial scratching (ES).

Objective

The purpose was to investigate endometrial responses to scratching by profiling angiogenesis-related gene expression in unexplained RIF participants.

Materials and Methods

In this randomized controlled trial study, 20 infertile women with unexplained RIF were assigned to 2 groups by the balanced block randomization method (n = 10/each group): the intervention group (group A) (who received ES in the follicular phase) and the control group (group B). Endometrial biopsy was performed in the secretory phase. Gene expression profiling was performed using a polymerase chain reaction-array kit for human-angiogenic growth factors. The implantation and clinical pregnancy rates were also assessed.

Results

Among the angiogenesis-promoting genes, FGF1, FGF13, FGF2, TGFA, ANG, ANGPT1, and VEGFA were significantly upregulated (p < 0.05). IL12A (an angiogenesis-inhibiting cytokine) was significantly upregulated (p < 0.01). In contrast, 15 genes with angiogenesis-related functions, including CXCL11, CXCL13, CXCL3, CXCL5, CXCL6, EREG, FIGF, FST, IL10, LEP, PPBP, PROK1, RHOB, TNF, and TYMP, were downregulated after ES. No significant differences were observed between the intervention (group A) and control (group B) groups in terms of implantation (43.75% vs. 28.57%) or clinical pregnancy rates (75% vs. 57.1%).

Conclusion

ES induced significant alterations in the expression of angiogenesis-related genes, with notable up/downregulation of key angiogenic/antiangiogenic factors. These findings enhance our understanding of the molecular responses triggered by ES, underscoring the potential influence of ES on the complex processes of angiogenesis crucial for implantation.

Zishen Yutai Pills Promote Angiogenesis at the Maternal-Fetal Interface in Recurrent Spontaneous Abortion Mice by Regulating miR-187/VEGF Axis

Ethnopharmacological Relevance

Zishen Yutai pills (ZYP), a traditional Chinese patent medicine, was listed in China in 1981. It is composed of 15 traditional Chinese medicines and has the effects of regulating menstruation, helping pregnancy, and preventing abortion. In clinical practice, it is effective in preventing habitual and threatened miscarriages, and continuing to explore its mechanism of action is very meaningful research.

Aim of the Study

To explore the possible mechanism of ZYP promoting angiogenesis at the maternal-fetal interface in recurrent spontaneous abortion (RSA).

Materials and Methods

In vitro experiments, placental trophoblast cells (PTCs) were isolated from the placental tissue of RSA mice and divided into six groups: Control group, Model group, ZYP group, miR-187 inhibitor NC group, miR-18 7 inhibitor group, and miR-187 inhibitor+ZYP group. Cell viability and cell cycle were measured using CCK8 and flow cytometry, respectively. The expression levels of miR-187, VEGF, VEGF-R1, and VEGF-R2 were measured using RT-qPCR, WB, and IF staining. Animal experiments first establish an RSA mice model (CBA/J × DBA/2) and then randomly divide the mice into four groups (n=10): normal pregnancy group, RSA model group, ZYP group, and progesterone capsule group. Observed the changes in embryo absorption rate, pathological morphology of decidual tissue, and ultrastructure of vascular endothelial cells in each group of mice. RT-qPCR, WB, and IF staining methods were used to determine the expression of miR-187, VEGF, VEGF-R1, and VEGF-R2.

Results

In vitro, ZYP promoted the viability of PTCs and regulated their cell cycle, and ZYP down-regulated miR-187, up-regulated VEGF, VEGF-R1 and VEGF-R2 levels. miR-187 inhibitor showed the same effects, and further ZYP intervention enhanced the effects. In vivo, ZYP remarkably reduced embryo resorption rates, and improved the pathological morphology of decidual tissues and ultrastructure of vascular endothelial cells. Moreover, ZYP down-regulated miR-187, up-regulated VEGF, VEGF-R1 and VEGF-R2.

Conclusion

In summary, ZYP can regulate the expression of VEGF via miR-187, then promote the angiogenesis at the maternal-fetal interface, and playing a therapeutic role in RSA.

MiR-150-5p contributes to unexplained recurrent spontaneous abortion by targeting VEGFA and downregulating the PI3K/AKT/mTOR signaling pathway

PURPOSE

The purpose of this study is to investigate the function of miR-150-5p in URSA.

METHOD

Twenty-six chorionic villous tissues were collected to examine the expression of miR-150-5p and VEGFA by using quantitative polymerase chain reaction (qPCR) and western blot assay, respectively. Transwell assay was conducted to assess the migration and invasion ability of trophoblast cells. The dual-luciferase reporter assay was applied to determine the relationship between miR-150-5p and VEGFA in vitro. Relevant signaling pathway protein expression level was measured via western blot assay. Signaling transduction inhibitor LY294002 was used to block PI3K/AKT/mTOR signaling pathway. Finally, in vivo the effect of miR-150-5p on embryonic absorption rate was evaluated in mice.

RESULTS

Clinical samples revealed that miR-150-5p expression was significantly elevated in the villous tissues and serum of URSA patients. Moreover, the overexpressing of miR-150-5p could inhibit both HTR-8/SVneo cell and JAR cell migration, invasion, and restrained PI3K/AKT/mTOR signaling pathway by targeting VEGFA in vitro. This inhibitory effect of miR-150-5p could be reversed by overexpressing the gene of vascular epithelial growth factor A (VEGFA). In contrary, inhibition of miR-150-5p significantly enhanced migration, invasion ability of both HTR-8/SVneo and JAR cells, and also could stimulate PI3K/AKT/mTOR signaling pathway. This promoting effect of miR-150-5p could be ameliorated by LY294002 (PI3K inhibitor). Finally, after miR-150-5p overexpression in vivo, the embryo resorption rate in pregnant mice was increased significantly.

CONCLUSIONS

Overall, these findings imply that miR-150-5p is among the key factors that regulate the pathogenesis of URSA.

Efficacy and safety of Gushen Antai Pills combined with dydrogesterone in the treatment of threatened miscarriage: a systematic review and meta-analysis

Background: Despite some progress has been made in the pathogenesis and treatment of threatened miscarriage (TM), conventional treatment remains suboptimal. Thus, complementary medicine gradually become a new treatment option for treating threatened miscarriage. Gushen Antai Pills (GAP), a classic prescription of Traditional Chinese medicine (TCM), has became a popular complementary therapy to conventional western medicine (dydrogesterone) in treating threatened miscarriage in recent years. However, a systematic summary and analysis for its therapeutic effects is lacking. This meta-analysis aimed to systematically evaluate the effectiveness and safety of Gushen Antai Pills combined with dydrogesterone in the treatment of threatened miscarriage. Methods: A systematic search across seven electronic databases was conducted from inception to 17 September 2022. Studies were included if they were randomized controlled trials (RCTs) evaluating the effect of integrating Gushen Antai Pills and dydrogesterone in patients with threatened miscarriage, and reported the outcomes of interest. All statistical analyses were conducted using the Revman5.3 and Stata 13 software. The GRADE system was used to evaluate the quality of evidence. Results: Ten eligible randomized controlled trials involving 950 participants were contained in this meta-analysis. The pooled analysis showed that Gushen Antai Pills combined with dydrogesterone can significantly reduce the incidence of early pregnancy loss (RR: 0.29; 95% CI: 0.19-0.42; p < 0.00001) and alleviate clinical symptoms (RR: 1.39; 95% CI: 1.22-1.59; p < 0.00001), compared with treatment of dydrogesterone alone. Also, meta-analysis indicated that integrating Gushen Antai Pills and dydrogesterone is more effective than using dydrogesterone alone in improving hormone levels (serum levels of progesterone, β-HCG and estradiol) for women with threatened miscarriage (all p < 0.00001). Meanwhile, the combined effects with significant heterogeneity also showed favorable consistency in the sensitivity analyses, indicating a good stability of present results. Moreover, no significant differences between Gushen Antai Pills combined with dydrogesterone and control group on adverse events was identified. The overall GRADE qualities were low to moderate. Conclusion: The overall available evidence suggested that Gushen Antai Pills combined with dydrogesterone had significant effects in improving pregnancy success rate, clinical symptoms and hormone levels for women with threatened miscarriage, with considerable safety and reliability. However, due to the partial heterogeneity, suboptimal quality and high risk of bias of some included studies, further rigorously designed randomized controlled trials are required. Systematic Review Registration: identifier https://INPLASY2022120035, https://inplasy.com/inplasy-2022-12-0035/.

The Association of Soluble VEGFR-1 Serum Level and Genetic (rs7993418) Polymorphism with In Vitro Fertilization and Embryo Transfer Outcome in the Population of Northern Iran

Background

Vascular endothelial growth factor receptors (VEGFRS) play an important role in embryo implantation. The aim of the present study was to examine the association of VEGFR1 circulating level and gene polymorphism with in vitro fertilization and embryo transfer (IVF-ET) outcome.

Methods

In this case-control study, 120 women who had unsuccessful IVF (IVF-) history and 120 women who had successful IVF outcome (IVF+) as controls were included. Genomic DNA was extracted from blood samples. Genotyping was performed using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). The serum levels of soluble VEGFR1 (sVEGFR1) were measured by ELISA. ANOVA test was used for statistical analysis.

Results

The frequency of T and C alleles in IVF+ individuals were 87.5%, 12.5% and among IVF- were 75.5%, 24.5%, respectively (p=0.0006). The minor allele (C) was associated with an increased risk of IVF failure based on results from co-dominant (OR=3.86, 95%CI 1.19-12.47), dominant (OR=2.32, 95%CI 1.31-4.10), recessive (OR=3.22, 95%CI 1.00-10.29), and allele models (OR=2.28, 95%CI 1.40-3.69). We also showed that there is a significant decrease in serum sVEGFR1 levels in IVF as compared to IVF+ (p=0.006) groups. Moreover, TT genotype is significantly associated with increased serum sVEGFR1 concentration in IVF group (TT, CT, and CC serum levels were 106.55±11.04, 94.33±10.75, and 83.33±9.13 ng/ml, and in IVF+ group were 156.11±18.08, 120.66±16.51, and 84.66±20.31 ng/ml, respectively).

Conclusion

The results of this study indicate that VEGFR1 polymorphism and sVEGFR1 circulating levels are associated with IVF-ET outcome. Moreover, CC genotype is associated with decreased sVEGFR-1 serum concentration and IVF-ET failure.

Expression deregulation of matrix metalloproteinases and vasoconstriction related genes in Pakistani females with abnormal uterine bleeding

BACKGROUND

Abnormal uterine bleeding (AUB) is irregular menstrual bleeding which has great impact on female health and life style. Various genetic factors are involved in etiology and pathology of AUB. Present study was designed to explore the association of PTGFR, MMP9, MMP2, TGFB3 and VEGFB with AUB.

METHODS

Blood samples of 212 females with AUB were collected along with age-matched healthy control. Expression variation of targeted genes was evaluated using qPCR. Present study cohort was divided into different groups based on demographic parameters and all targeted genes were correlated with study demographics.

RESULTS

Expression of targeted genes was significantly (P < 0.001) downregulated in females with AUB compared to control. Reduced (P < 0.01) expression of targeted genes was observed in all age groups (21-30, 31-40, 41-50 year) of AUB patients compared to respective control. Expression of VEGFB increased (P < 0.05) in AUB females with > 9 days bleeding compared to AUB patient had < 9 days bleeding. AUB women with miscarriage history showed upregulation in MMP2, TGFB3 (P < 0.05), and downregulation in MMP9 and VEGFB (P < 0.05) expression compared to AUB group with no miscarriage history. Expression of MMP2 increased (P < 0.05) in AUB females with > 60 kg body weigh compared to AUB patient with < 60 kg weight.

CONCLUSION

Present study open a new window for diagnosis of AUB at early stages and suggested a possible involvement of PTGFR, MMP9, MMP2, TGFB3 and VEGFB as candidate biomarkers in AUB.

Role of microRNAs in trophoblast invasion and spiral artery remodeling: Implications for preeclampsia

It is now well-established that microRNAs (miRNAs) are important regulators of gene expression. The role of miRNAs in placental development and trophoblast function is constantly expanding. Trophoblast invasion and their ability to remodel uterine spiral arteries are essential for proper placental development and successful pregnancy outcome. Many miRNAs are reported to be dysregulated in pregnancy complications, especially preeclampsia and they exert various regulatory effects on trophoblasts. In this review, we provide a brief overview of miRNA biogenesis and their mechanism of action, as well as of trophoblasts differentiation, invasion and spiral artery remodeling. We then discuss the role of miRNAs in trophoblasts invasion and spiral artery remodeling, focusing on miRNAs that have been thoroughly investigated, especially using multiple model systems. We also discuss the potential role of miRNAs in the pathogenesis of preeclampsia.

Placenta-Specific miR-125b Overexpression Leads to Increased Rates of Pregnancy Loss in Mice

Pregnancy loss (PL) is one of the common complications that women can experience during pregnancy, with an occurrence rate of 1 to 5%. The potential causes of pregnancy loss are unclear, with no effective treatment modalities being available. It has been previously reported that the level of miR-125b was significantly increased in placentas of PL patients. However, the role of miR-125b in the development of PL still remains unknown. In the current study, an miR-125b placenta-specific over-expression model was constructed by lentiviral transfecting zona-free mouse embryos followed by embryo transfer. On gestation day 15, it was observed that the placenta was significantly smaller in the miR-125b placenta-specific overexpression group than the control group. Additionally, the abortion rate of the miR-125b placenta-specific overexpression group was markedly higher than in the control group. The blood vessel diameter was larger in the miR-125b-overexpressing specific placenta. In addition, miR-125b-overexpressing HTR8 and JEG3 cell lines were also generated to analyze the migration and invasion ability of trophoblasts. The results showed that miR-125b overexpression significantly suppressed the migration and invasion ability of HTR8 and JEG3 cells. Overall, our results demonstrated that miR-125b can affect embryo implantation through modulating placenta angiogenesis and trophoblast cell invasion capacity that can lead to PL.

The role of oxidative stress in patients with recurrent pregnancy loss: a review

BACKGROUND

Recurrent pregnancy loss (RPL) presents one of the main problems in the field of reproductive medicine, due to the unknown etiology in 50% of cases, as well as limited evidence-based diagnostic and therapeutic modalities. Recent studies indicate that systemic and placental oxidative stress (OS) represents an essential factor in the etiopathogenesis of RPL. This article is a comprehensive narrative synthesis of previously published studies concerning the role of oxidative stress in the etiology of recurrent pregnancy loss.

METHODS

We conducted literature search of published studies in the English language focusing on oxidative stress and its association with recurrent pregnancy loss (RPL) utilizing the Medline and Cochrane databases from 2000 through January 2021. The keywords used were "recurrent pregnancy loss" "oxidative stress and recurrent pregnancy loss" and "oxidative stress biomarkers and recurrent pregnancy loss".

RESULTS

The search yielded 1116 publications, of which 92 were included in the final analysis. Reactive oxygen species (ROS) and reactive nitrogen species (RNS) at basal levels have various physiological functions whereas deviation from redox window is associated with different pathologies including early pregnancy loss. The currently available studies support the concept that increased oxidative stress (OS) and deficient antioxidant protection is implicated in the etiology of recurrent pregnancy loss (RPL) but underlying mechanisms through which OS affects pregnancy outcome remains largely indefinable.

CONCLUSIONS

Future research in this field can provide new insights regarding the OS-mediated damage in recurrent pregnancy loss as well as potential applications of antioxidant therapy in this group of patients.

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.

Role of Vascular Endothelial Growth Factor (VEGF) in Human Embryo Implantation: Clinical Implications

Vascular endothelial growth factor (VEGF) is a well-known angiogenic factor that plays a critical role in various physiological and pathological processes. VEGF also contributes to the process of embryo implantation by enhancing embryo development, improving endometrial receptivity, and facilitating the interactions between the developing embryo and the endometrium. There is a correlation between the alteration of VEGF expression and reproductive failure, including recurrent implantation failure (RIF) and recurrent miscarriage (RM). In order to clarify the role of VEGF in embryo implantation, we reviewed recent literature concerning the expression and function of VEGF in the reproductive system around the time of embryo implantation and we provide a summary of the findings reported so far. We also explored the effects and the possible underlying mechanisms of action of VEGF in embryo implantation.

Gene expression analysis of membrane progesterone receptors in women with recurrent spontaneous abortion: a case control study

Objective

Recurrent spontaneous abortion (RSA) is a condition which is defined as three consecutive pregnancy losses prior to 20 weeks from the last menstrual period. Progesterone is a steroid hormone that has an essential role in the implantation and maintenance of pregnancy. The progesterone signaling is performed by nuclear progesterone receptors (NPRs) and membrane progesterone receptors (mPR). The aim of this study was to analyze gene expression of mPR-α, mPR-β and NPR in the endometrium of patients with a history of RSA compared to normal fertile women.

Results

In this study, endometrial samples were obtained from 10 women with a history of RSA and 10 fertile women during days 10–14 of menstrual cycle. Relative expression of mPR-α, mPR-β and NPR genes were studied by a quantitative real time polymerase chain reaction (qRT-PCR) and compared between the two groups. The mean relative expression of mPR-β gene was significantly lower in the case group compared to the fertile women (p < 0.05). However, the gene expression of mPR-α and NPR showed no significant difference between two groups. The findings suggest a reduction of endometrial gene expression of mPR-β in RSA patients may play an important role in pathogenesis of RSA.

Case Control Study to Compare Serum Vascular Endothelial Growth Factor (VEGF) Level in Women with Recurrent Pregnancy Loss (RPL) Compared to Women with Term Pregnancy

INTRODUCTION

Recurrent pregnancy loss (RPL) is defined as three or more spontaneous pregnancy losses before the 20th week of gestation or fetal weight of < 500 gm from the last menstrual period. Vascular endothelial growth factor (VEGF) is essential for implantation, development of embryo and placental angiogenesis. Women with low VEGF level are believed to be at higher risk of RPL.

OBJECTIVE

To measure the level of VEGF in women with RPL and compare it with women with 1 or more successful pregnancies.

METHODS

This is a Case control study carried out in King George Medical University, Lucknow from August 2015 to 2016. Participants sample size was 60 women. Thirty women with 3 or more spontaneous abortions were included as cases, and 30 women with at least 1 successful term pregnancy were controls. Serum VEGF level was analyzed using ELISA kit. Main outcome measured: 1. Serum VEGF level in the two groups. 2. Serum VEGF level in different underlying etiologies in women with RPL.

RESULTS

Mean VEGF level was 105.3 pg/mL in RPL cases, while it was 156.8 pg/mL in fertile controls. (p = 0.01). VEGF level was 86.2 pg/mL in patients with anatomical defects, 109 pg/mL in APLA syndrome, 85.1 pg/mL in hypothyroidism and 122.2 pg/mL in unexplained RPL.

CONCLUSION

The mean serum VEGF level was significantly lower in women with recurrent pregnancy loss compared with women with successful term pregnancy, implicating its role in maintaining pregnancy.

Genetics of recurrent pregnancy loss among Iranian population

Background

Recurrent pregnancy loss (RPL) is one of the most common reproductive disorders which is defined as the occurrence of recurrent miscarriage before 24 weeks of gestation and is observed among 1%–5% of women.

Methods

Various factors are associated with RPL such as immunological disorders, maternal age, obesity, alcohol, chromosomal abnormality, endocrine disorders, and uterine abnormalities. About half of the RPL cases are related with chromosomal abnormalities. Therefore, RPL genetic tests are mainly limited to karyotyping. However, there is a significant proportion of RPL cases without any chromosomal abnormalities that can be related to the single‐gene aberrations. Therefore, it is required to prepare a diagnostic panel of genetic markers besides karyotyping.

Results

In the present review, we have summarized all the significant reported genes until now which are associated with RPL among Iranian women. We categorized all the reported genes based on their cellular and molecular functions in order to determine the molecular bases of RPL in this population.

Conclusion

This review paves the way of introducing a population‐based diagnostic panel of genetic markers for the first time among Iranian RPL cases. Moreover, this review clarifies the genetic and molecular bases of RPL in this population.

The interaction effect of angiogenesis and endothelial dysfunction-related gene variants increases the susceptibility of recurrent pregnancy loss

PURPOSE

The role of genetic polymorphisms in the pathogenesis of recurrent pregnancy loss (RPL) has been studied intensively. Complex diseases, including miscarriage, are believed to have a polygenic basis, and gene-gene interactions can play a significant role in the etiology of the disease. This study was conducted to investigate the association of gene-gene interactions with angiogenesis, endothelial dysfunction-related gene polymorphisms, and RPL.

METHODS

A case-control study was conducted with 253 unrelated RPL patients with 2 or more spontaneous pregnancy losses and 339 healthy women with no history of pregnancy complications. Genotyping of single-nucleotide polymorphisms (SNPs) was performed using real-time polymerase chain reaction (real-time PCR), restriction fragment length polymorphism (RFLP), or allele-specific polymerase chain reaction methods.

RESULTS

The genotypes 677TT of the MTHFR gene, 936TT, 936CT, and 634CC, 634GC of the VEGF gene, and allele 894T of the NOS3 gene were associated with a predisposition to RPL in the Russian population. A significant role of additive and epistatic effects in the gene-gene interactions of the SNPs of SERPINE-1, ACE, NOS3, MTHFR, and VEGF genes in RPL was demonstrated.

CONCLUSIONS

The results showed that gene-gene interactions are important for RPL susceptibility. Additionally, analysis of the genotype combinations of several allelic variants provides more information on RPL risk than analysis of independent polymorphic markers.

The -2549 insertion/deletion polymorphism in the promoter region of VEGF is associated with the risk of recurrent spontaneous abortion

Recurrent spontaneous abortion (RSA) is a common health problem affecting women of reproductive age. Altered expression of vascular endothelial growth factor (VEGF) has been associated with spontaneous abortion. The present case-control study aimed to evaluate the impact of the 18-bp insertion/deletion (ins/del) polymorphism (rs35569394) in the promoter region of the VEGF gene on idiopathic RSA. Genomic DNA from 93 patients with RSA and 93 healthy fertile women of southeastern Iran was isolated using the salting-out method. Genotyping of the rs35569394 variant was performed by a polymerase chain reaction (PCR) method. The findings indicated that the VEGF 18-bp ins/del variant significantly increased the risk of RSA under codominant (ins/ins vs. del/del; OR=2.85, 95% CI=1.31-6.22, P=0.019), dominant (del/ins+ins/ins vs. del/del; OR=2.19, 95% CI=1.20-4.01, P=0.015) and allelic (ins vs. del; OR=1.90, 95% CI=1.25-2.88, P=0.003) inheritance models. In summary, the findings propose a significant association between the VEGF 18-bp ins/del polymorphism and risk of RSA in a sample of the southeast Iranian population. Further studies on larger sample sizes and different ethnicities are required to validate the present findings.

Elevated Levels of Serum Vascular Endothelial Growth Factor-A Are Not Related to NK Cell Parameters in Recurrent IVF Failure

BACKGROUND

Vascular Endothelial Growth Factor and NK cells have an interrelated role in angiogenesis that is critical for placentation and success of in vitro fertilization. An attempt was made to assess a possible relationship between the two in this study.

METHODS

A case control study was performed comparing the serum levels of VEGF-A and its receptor VEGF-R1 with levels of NK cells, activated NK cells and NK cytotoxicity in 62 women with Repeated Implantation Failure (RIF). The healthy control group consisted of 72 women of similar age, without known issues in achieving pregnancy or evidence of autoimmunity. Levels of VEGF-A and VEGF-R1 were quantified by ELISA methods with standard curve interpolation. NK cell subsets were determined with flow cytometry using fluorescent-tagged anti-CD56, anti-CD16, anti-CD3 and anti-CD69. NK cytotoxicity was performed by incubating peripheral blood mononuclear cells and K562 cultured cells with propidium iodide, steroid, intralipid and intravenous immunoglobulin, using previously described methods. Statistical analysis involved Mann-Whitney-U and Spearman's rank correlation testing with p-values defined as <0.05.

RESULTS

It was found that VEGF-A levels were significantly raised in women with RIF compared to healthy controls (362.9 vs. 171.6 pg/ml, p<0.0001), with no difference in VEGF-R1 levels between groups (1499 vs. 1202 pg/ml, p=0.4082). There was no correlation between VEGF-A or VEGF-R1 and the absolute levels of circulating NK cells, CD69 activated NK cells or NK cytotoxicity.

CONCLUSION

The absence of correlation between VEGF-A or VEGF-R1 and NK cells suggests VEGF secretion and regulation is independent of NK cell activity in RIF.

MicroRNA-16 inhibits feto-maternal angiogenesis and causes recurrent spontaneous abortion by targeting vascular endothelial growth factor

Recurrent spontaneous abortion (RSA) is a common health problem that affects women of reproductive age. Recent studies have indicated that microRNAs are important factors in miscarriage. This study investigated the role of miR-16 in regulating vascular endothelial growth factor (VEGF) expression and the pathogenesis of RSA. In this report, clinical samples revealed that miR-16 expression was significantly elevated in the villi and decidua of RSA patients. In vitro, miR-16 upregulation inhibited human umbilical vein endothelial cell proliferation, migration and tube formation. Conversely, the downregulation of miR-16 reversed these effects. In vivo, we demonstrated that abnormal miR-16 levels affect the weights of the placenta and embryo and the number of progeny and microvascular density, as well as cause recurrent abortions by controlling VEGF expression in pregnant mice. VEGF, a potential target gene of miR-16, was inversely correlated with miR-16 expression in the decidua of clinical samples. Furthermore, the luciferase reporter system demonstrated that miR-16 was found to directly downregulate the expression of VEGF by binding a specific sequence of its 3′-untranslated region (3′UTR). Collectively, these data strongly suggest that miR-16 regulates placental angiogenesis and development by targeting VEGF expression and is involved in the pathogenesis of RSA.

Reduced expressions of connexin 43 and VEGF in the first-trimester tissues from women with recurrent pregnancy loss

BACKGROUND

Approximately 45-50 % of the recurrent pregnancy loss (RPL) remain(s) unexplained that challenges its clinical management. Formation and development of placenta as well as angiogenesis are critical for successful pregnancy. Vascular endothelial growth factor (VEGF) and connexin 43 (Cx43) play important roles in angiogenesis and placenta development and aberration of these have been linked to RPL. We aimed to investigate whether the expressions of VEGF and Cx43 were altered in the first-trimester tissues (chorionic villi and decidua) collected from women with RPL compared to those from healthy early pregnant women.

METHODS

First-trimester chorionic villi and decidua were collected from pregnant women diagnosed RPL who ended up with surgical intervention (n = 28) in comparison to those collected from women requesting surgical termination of their unwanted normal first-trimester pregnancies (n = 28). These two groups of women were matched in age and gestational weeks. Tissues were analyzed for the protein and messenger ribonucleic acid (mRNA) expressions of Cx43 and VEGF by immunohistochemistry, western blot, and quantitative reverse transcription polymerase chain reaction (qRT-PCR).

RESULTS

The expressions of both Cx43 and VEGF at the level of mRNA and protein in the villi and decidua from women with RPL were significantly decreased compared with those from women with normal early pregnancy.

CONCLUSIONS

Reduction of Cx43 and VEGF expressed in the first-trimester tissues might indicate their important roles involved in RPL and thus holds the potential to develop pharmaceutical therapies for treatment of RPL.

The -2549 insertion/deletion polymorphism in the promoter region of the VEGFA gene in couples with idiopathic recurrent spontaneous abortion

PURPOSE

The vascular endothelial growth factor A (VEGFA) is crucial for normal vasculogenesis and angiogenesis during pregnancy, and alterations in the VEGFA gene expression were detected in women with idiopathic recurrent spontaneous abortion (IRSA) and spontaneously aborted conceptuses. Our aim was to evaluate whether there is an association between the functional -2549 insertion/deletion (I/D) polymorphism in the promoter region of the VEGFA gene and IRSA in reproductive couples.

METHODS

We performed a case-control study involving 149 women and their 140 partners with three or more IRSA and 149 control women and men. Allele-specific polymerase chain reaction was used for genotyping.

RESULTS

We found no association of the -2549 I/D polymorphism with IRSA in women. However, men with the DD genotype have a 1.75-fold increased risk of IRSA compared with men carrying the ID and II genotypes (95 % confidence interval (CI) = 1.05-2.93, P = 0.032). In addition, the D allele in men contributes to a 1.42-fold increased risk of IRSA (95 % CI = 1.02-1.97, P = 0.036) compared to men carrying the I allele.

CONCLUSIONS

Our results indicate that the -2549 I/D polymorphism in the VEGFA gene in men might be associated with IRSA. Additional genetic association studies including both partners, as well as expression studies, are needed to elucidate the role of this polymorphism in IRSA.

mRNA expression of VEGF and its receptors in fallopian tubes of women with ectopic pregnancies

BACKGROUND

Establishment of viable pregnancy requires embryo implantation and placentation. Ectopic pregnancy (EP) is a pregnancy complication which occurs when an embryo implants outside of the uterine cavity, most often in a fallopian tube. On the other hand, an important aspect of successful implantation is angiogenesis. Vascular endothelial growth factor (VEGF) is a potent angiogenic factor responsible for vascular development that acts through its receptors, VEGF receptor 1 (VEGFR1) and VEGFR2. This study aims to investigate mRNA expression of VEGF and its receptors in fallopian tubes of women who have EP compared with fallopian tubes of pseudo-pregnant women. We hypothesize that expression of VEGF and its receptors in human fallopian tubes may change during EP.

MATERIALS AND METHODS

This was a case-control study. The case group consisted of women who underwent salpingectomy because of EP. The control group consisted of women with normal fallopian tubes that underwent hysterectomy. Prior to tubal sampling, each control subject received an injection of human chorionic gonadotropin (hCG) to produce a state of pseudo-pregnancy. Fallopian tubes from both groups were procured. We investigated VEGF, VEGFR1 and VEGFR2 mRNA expressions in different sections of these tubes (infundibulum, ampulla and isthmus) by reverse transcription polymerase chain reaction (RT-PCR) and quantitative PCR (Q-PCR).

RESULTS

RT-PCR showed expressions of these genes in all sections of the fallopian tubes in both groups. Q-PCR analysis revealed that expressions of VEGF, VEGFR1 and VEGFR2 were lower in all sections of the fallopian tubes from the case group compared to the controls. Only VEGFR2 had higher expression in the ampulla of the case group.

CONCLUSION

Decreased expressions of VEGF, VEGFR1 and VEGFR2 in the EP group may have a role in the pathogenesis of embryo implantation in fallopian tubes.