Vascular Endothelial Growth Factor Variants Research Articles

Genetic studies in the Pakistani population reveal novel associations with ventricular septal defects (VSDs)

BackgroundWith prevalence up to 4%, Ventricular Septal Defect (VSD) is one of the leading causes of neonatal deaths. VSD is a common complex genetic disorder that has been associated with many genetic determinants. Variants from genes for the transcription factors including T-Box TBX5 and NFATc1 (nuclear factor of activated T cells, cytoplasmic 1), Vascular endothelial growth factor (VEGF), ISLET1 (encoded by the ISL1 gene) and enzyme MTHFR, a methylene tetrahydrofolate reductase were selected. Genetic risk score (GRS) is a widely accepted approach used to convert the genetic data into prediction and assessment tool for disease susceptibility.MethodsA total of 200 participants were recruited for the current study, 100 VSD patients and 100 controls. Genotyping of the ISL1: rs1017, NFATc1: rs7240256, VEGF: rs36208048, TBX5: rs11067075, and MTHFR: rs1801133 variants was performed using tetra primer ARMS PCR and PCR-RFLP. For the statistical analysis, the software SPSS version 23 was used. Genotypic frequencies of cases and controls were calculated using chi-square (χ²) whereas allelic frequencies were calculated by using the SNPStats tool. The association of GRS quartiles with VSD was examined using binary logistic regression. Adjusted p-value 0.01 was used as significance threshold for all analyses.ResultsThe ISL1 (OD: 0.242, CI: 0.158–0.37, p-value: 2.15 × 10− 4 :), NFATc1 (OD: 2.53, CI: 1.64–3.89, p-value: 2.11 × 10− 5), TBX5 (OD: 2.24, CI: 1.47–3.41, p-value:1.6 × 10− 4) and MTHFR (OD: 10.46, CI: 5.68–19.26, p-value: 2.09 × 10− 9:) variants were found to be in association with VSD. In contrast, the VEGF (OD: 0.952, CI: 0.56–1.62, p-value: 0.8921) variant did not show significance association with the VSD. For cases, the mean GRS score was 3.78 ± 1.285 while in controls it was 2.95 ± 1.290 (p-value: 0.479, CI: 0.474–1.190). Comparison of GRS between cases and control showed that mean GRS of cases was 1.90 ± 0.480 while in controls it was 1.68 ± 0.490 (p-value: 0.001, CI: 0.086–0.354). Higher quartiles were more prevalent in cases whereas lower quartiles were more prevalent in controls.ConclusionGRS of these five loci was strongly associated with VSD. Moreover, genetic risk score can provide better information for the association between variants and disease as compared to a single SNP. We also illustrated that the cumulative power of GRS is greater over the single SNP effect. This is a pilot scale study with a relatively small sample size whose findings should be replicated in a larger sample size for the unique local Pakistani population.

The VEGF/VEGFR Axis Revisited: Implications for Cancer Therapy

The vascular endothelial growth factor (VEGF)/vascular endothelial growth factor receptor (VEGFR) axis is indispensable in the process of angiogenesis and has been implicated as a key driver of tumor vascularization. Consequently, several strategies that target VEGF and its cognate receptors, VEGFR-1 and VEGFR-2, have been designed to treat cancer. While therapies targeting full-length VEGF have resulted in an improvement in both overall survival and progression-free survival in various cancers, these benefits have been modest. In addition, the inhibition of VEGFRs is associated with undesirable off-target effects. Moreover, VEGF splice variants that modulate sprouting and non-sprouting angiogenesis have been identified in recent years. Cues within the tumor microenvironment determine the expression patterns of these variants. Noteworthy is that the mechanisms of action of these variants challenge the established norm of VEGF signaling. Furthermore, the aberrant expression of some of these variants has been observed in several cancers. Herein, developments in the understanding of the VEGF/VEGFR axis and the splice products of these molecules, as well as the environmental cues that regulate these variants are reviewed. Furthermore, strategies that incorporate the targeting of VEGF variants to enhance the effectiveness of antiangiogenic therapies in the clinical setting are discussed.

VEGF and eNOS variants may influence intervertebral disc degeneration

Background: Intervertebral disc degeneration (IDD) is a common and complex condition. Vascular endothelial growth factor (VEGF) is one of the key regulators of angiogenesis and vascular permeability. Nitric oxide (NO) plays a role in various physiological events. The endothelial nitric oxide synthase (eNOS) that catalyses NO generation are crucial for the regulation of NO level. This study aimed to evaluate the association between VEGF/ eNOS gene variants with IDD. Materials and Methods: Two hundred ninety-one subjects (111 IDD patients and 180 controls) were included in the present case-control study. VEGF −2549 insertion/deletion (I/D) and eNOS VNTR variants were analysed by PCR method. The results of this analysis were evaluated for statistical significance. Results: There were no statistically significant differences in genotype and allele distribution of VEGF −2549 I/D/ eNOS VNTR variants between IDD patients and control subjects. We then evaluated the association between the allele frequencies of these variants and clinical features of IDD. Lumber IDD was more common in patients carrying VEGF I/D variant D allele (p < 0.001). Also, patients with lumbar disc herniation, cervical disc herniation, lumbar stenosis, and lumbar IDD had more 4 b allele (p = 0.005, p < 0.001, p < 0.001, and p = 0.03, respectively). Conclusions: In conclusion, this study demonstrates first time that some clinical characteristics of IDD have been associated with allele frequencies of VEGF −2549 I/D/ eNOS VNTR variants.

Implications of VEGF gene sequence variations and its expression in recurrent pregnancy loss

Research questionWhat is the association between VEGF gene sequence variants and its mRNA expression in recurrent pregnancy loss (RPL)? Vascular endothelial growth factor (VEGF) has a prominent role in pregnancy and affects pregnancy outcome. The association of VEGF gene 1154G>A, 634G>C and 583C>T polymorphic variations with cases of RPL and full-term fertile women as controls was investigated. DesignTwo hundred women with RPL and 240 women healthy controls were included. The restriction fragment length polymorphism method was used for genotyping and quantitative real-time polymerase chain reaction was used for analysis of mRNA expression. ResultsIn VEGF 1154G>A, significant differences were found in homozygous AA genotype between case and control participants. The variant allele A frequency was significantly more abundant in RPL cases (0.41) than controls (0.19) (P < 0.0001). Only RPL cases with the multi-generation family history of miscarriages and those without any history showed significant differences of combined genotype GA+AA (P < 0.0001). In VEGF 634 G>C, CC genotype and allele C showed significantly increased frequency in RPL cases compared with healthy controls (P < 0.0001). The association between VEGF-1154 G>A SNP and VEGF-A mRNA expression levels was significant in RPL cases (P = 0.004). Also in VEGF-583 C>T, CT genotypes were seen significantly associated with cases (P = 0.003). The heterozygous genotype GA was significantly (P = 0.03) associated with upregulation and downregulation of VEGF mRNA, whereas the homozygous variant genotype AA only leads to low expression levels of VEGF mRNA in patients with RPL. ConclusionsAll the variants of VEGF play a vital role in an increased susceptibility to RPL. Also, VEGF-1154, AA genotypes are associated with its altered low mRNA expression in women with RPL and seem to affect pregnancy outcome.

Evaluating the Value of the Genetic Risk Variants of Haem-Oxygenase-1, Vascular Endothelial Growth Factor and Vascular Endothelial Growth Factor Receptor-2 in Prediction of the Presence of Esophageal Varices in Patients with Liver Cirrhosis

Abstract Background: Current guidelines recommend screening for Esophageal Varices (EV) by Esophagogastroduodenoscopy (EGD) for all cirrhotic patients. The cost and invasive nature of endoscopic screening mean that there is an interest in developing noninvasive predictors for EV that would decrease the number of EGDs performed. The genetic factors that are involved in the development and maintenance of porto-systemic collateral circulation have been rarely investigated. Variation at the genes that encode proteins involved in the systemic and splanchnic vasodilation, which include angi-otensin-converting enzyme and endothelial/constitutive nitric oxide synthase, have been found to be involved in the EV risk among patients withcirrhosis. In cirrhosis, Vascular Endothelial Growth Factor (VEGF) receptor 2/VEGF and carbon monoxide (CO) activity are significantly increased and are closely correlated with porto-systemic collateral vasodilations. Haem-Oxygenase-1 (HO-1) is the main rate-limiting enzyme involved in CO production. Aim of Study: This study aimed at investigating the value of the genetic risk variants of HO-1, VEGF and VEGF Re-ceptor-2 (VEGFR-2) in prediction of the presence of EV in patients with liver cirrhosis. Patients and Methods: Our study included 300 Egyptian patients with liver cirrhosis, aged 18 years or older, with no history of gastrointestinal bleeding, hepatic schistosomiasis, hepatocellular carcinoma, injection sclerotherapy or band ligation for EV, surgery for portal hypertension or portal or splenic vein thrombosis by ultrasonography. Patients underwent EGD to evaluate the presence and degree of EV, fibroscan for detection of liver stiffness and genetic investigation of HO-1, VEGF and VEGFR-2. Demographic, biochemical and endoscopic data were collected. Patients were divided into Group I (no varices), Group II A (small varices), Group IIB (large varices) and Group III (100 healthy control subjects).Results: All groups were age & BMI matched, platelet count and serum albumin were significantly lower in group II B compared to groups I & II A (p-value <0.001), while serum bilirubin level was significantly higher in group II B compared to groups I & II A (p-value <0.001). TT genotype SNP of HO-1 was associated with the presence of EV, while low grade varices were more detected in patients who carry AT genotype. Other genetic risk variants of VEGF and VEGFR-2 were not helpful in the prediction of EV or in the differen-tiation between small and large varices. Conclusion: Genetic risk variants of HO-1 genotype are helpful in prediction of EV as well as in differentiation between small and large varices. Combining these genetic variants to other noninvasive parameters will be a more sensitive and specific tool to predict EV in cirrhotic patients; it may help to select patients for endoscopic screening and decrease the number of EGDs. However, further studies will be needed from the economic point of view to determine the applicability of using these noninvasive tools as predictors of varices instead of EGD.

ENOS and VEGF Variants Might Increase the Risk of Pancreatic Cancer

Background: Endothelial nitric oxide synthase (eNOS) is essential in chronic inflammation and carcinogenesis. The association between variants in vascular endothelial growth factor (VEGF) and several cancers still remains uncertain. We studied whether there is a relation between eNOS/VEGF variants and risk of pancreatic cancer (PC). Materials and Methods: This prospective case-control study included 76 PC patients (28 women and 48 men) and 100 healthy controls. Blood samples from all participants were genotyped for eNOS variable number tandem repeat (VNTR) and VEGF insertion/deletion (I/D) variants by PCR. Results: There was a significant difference between groups for the eNOS intron 4 VNTR genotype distributions (p = 0.01). eNOS 4a/4b and 4b/4b genotypes were higher in patients with PC group compared to controls while eNOS 4a/4b genotype was more prevalent in control group than in patient group. Significant differences were observed between groups for the VEGF I/D variant genotype and allele frequencies (p < 0.00, and p < 0.00). VEGF I/D variant I/I genotype and I allele increased in patient group than controls. A statistically significant association was observed when the patients were compared with the controls according to D/D + D/I versus D/D (p < 0.00, OR: 0.094, 95% CI: 0.03–0.22). Conclusions: We provided evidence that eNOS VNTR and VEGF I/D variants might influence the development of PC.

One Step Closer to a Cure for Preeclampsia?

One Step Closer to a Cure for Preeclampsia?

Affinity-Enhanced Multimeric VEGF (Vascular Endothelial Growth Factor) and PlGF (Placental Growth Factor) Variants for Specific Adsorption of sFlt-1 to Restore Angiogenic Balance in Preeclampsia.

Preeclampsia is a potentially life-threatening multisystem disease affecting 4% to 8% of pregnant women after the 20th week of gestation. An excess of placental expressed antiangiogenic soluble VEGF (vascular endothelial growth factor)-receptor 1 (soluble FMS-like tyrosine kinase 1) scavenges VEGF and PlGF (placental growth factor), causing generalized endothelial dysfunction. Interventions to restore the angiogenic balance in preeclamptic pregnancies are intensively studied and improve maternal and neonatal outcomes. Especially extracorporeal strategies to remove sFlt-1 are promising in human pregnancy. However, available apheresis systems adsorb sFlt-1 unspecifically and with low efficiency. Affinity-enhanced ligands are needed to improve performance and compatibility of apheresis treatments. Using computerized molecular modeling, we developed multimeric VEGF molecules comprised of single-chain VEGF165 dimers (scVEGF165). A short peptide linker hampers intrachain dimerization to induce assembly preferably as tetrameric molecules as visualized in negative staining electron microscopy. scVEGF165 multimers possess 1.2-fold higher affinity for sFlt-1 as compared to the available antibodies or monomeric VEGF. Consequently, scVEGF multimers have the ability to competitively release sFlt-1 bound PlGF and, in particular, VEGF. In ex vivo adsorption experiments using serum samples from patients with preeclampsia, scVEGF multimers reduce sFlt-1 levels by 85% and increase PlGF and VEGF levels by 20- and 9-fold, respectively. Finally, performance and stability of sFlt-1 capturing scVEGF165 multimers were scrutinized on different matrices of which biocompatible agarose matrix yielded optimal results. We introduce the first VEGF-based highly efficient sFlt-1 apheresis system that is directly applicable in vivo due to utilization of inert agarose matrix, using a homomultimeric form of VEGF165 to restore the angiogenic balance in preeclampsia.

Circulation of orf viruses containing the NZ7-like vascular endothelial growth factor (VEGF-E) gene type in India

Orf, a poxviral skin infection of small ruminants is caused by orf virus (ORFV) of the genus Parapoxvirus of the Poxviridae family. Vascular endothelial growth factor (VEGF) is an important virulence factor that is responsible for proliferative lesions in parapoxviral infections. VEGF gene shows high intra- and inter-species variability. Two variants of VEGF have been described globally in ORFV, viz. NZ2- and NZ7-like. In the present study, ORFV isolates of different geographic regions of India were analysed on the basis of the VEGF gene. Indian ORFV isolates showed 95.7–100 % nucleotide (nt) and 78.4–99.3 % amino acid (aa) identity with each other, except ORFV-Assam/LK/14 and ORFV-Meghalaya/03 which shared 85.1–88.35 % and 79.1–81.8 % identity, at nt and aa levels, respectively with other Indian ORFV isolates. All Indian ORFVs under the study demonstrated 83.5–99.1 % nt and 80.5–97.9 % aa identity with NZ7-like VEGF as compared to 41.2–44.8 % nt and 30.7–38.4 % aa identity with NZ2-like VEGF on comparison with global ORFV strains. Phylogenetic analysis based on the VEGF gene showed two clusters of ORFV in which the Indian ORFVs clustered with NZ7-like VEGF from global ORFV strains, mostly from China. Despite the considerable variation, VEGF protein from Indian ORFV strains showed conserved VEGF homology domain with eight cysteine residues. Homology modeling of Indian ORFV strains predicted the presence of extended Loop 3 similar to NZ7-like VEGF. Therefore, the present study showed the circulation of ORFV strains with comparatively less variable NZ7-like VEGF in India which implicates its importance in the epidemiology of ORFV infections in the country.

The -2549 -2567 del18 Polymorphism in VEGF and Irreversible Bronchoconstriction in Asthmatics.

While the importance of vascular endothelial growth factor (VEGF) in the pathogenesis of several diseases (eg, neoplasms) has been proven, its role in asthma, especially in terms of the potential associations between genetic variants of VEGF and airway remodeling, has received relatively little attention. Objectives: This study aimed to evaluate the possible connection between a genetic factor, ie, the polymorphism del/ins in the VEGF promoter region, and airway remodeling potential in asthmatics with and without irreversible bronchoconstriction. The study population comprised 82 patients with asthma (of whom 42 had irreversible bronchoconstriction) and a group of 40 controls. DNA was isolated from peripheral blood leukocytes. Polymerase chain reaction was used to type the VEGF (18-bp deletion/insertion) gene polymorphism at loci -2549 -2567. Other factors (ie, smoking, disease duration) were also taken into consideration. The del/del genotype was found in 74.39% of patients with asthma (P=.031; OR=2.38), 80.95% of patients with irreversible bronchoconstriction (P=.012; OR=3.48), and 67.5% patients with reversible bronchoconstriction (P=.251; OR=1.70). The proportion of smokers to nonsmokers was higher (P=.032) and disease duration was longer (P=.041) in patients with irreversible bronchoconstriction than in those with reversible bronchoconstriction. Our results showed that the risk of irreversible bronchoconstriction in asthmatics was associated with the presence of the del18 genotype at the -2549 -2567 position in the promoter region of the VEGF gene, as were disease duration and other factors such as smoking.

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

Vascular endothelial growth factor (VEGF) is a well-known factor in reproductive function and contributes to the pathogenesis of polycystic ovary syndrome (PCOS). Genetic variations in VEGFA gene were suggested to contribute alterations in VEGF secretion and PCOS. This study evaluated the association of VEGFA SNPs with altered VEGF secretion level and PCOS among ethnically-matched control women. This prospective case-control study was conducted from 2016 to 2018 and comprised of 55 women with PCOS and 52 control subjects. ELISA was used to measure VEGF levels; and various other related bio chemicals whereas the genotyping of VEGFA variants was performed through the analysis of nine SNPs of VEGF. PRL, E2, PRGE testosterone and glucose level were found to be insignificantly different. The levels of FSH, LH, LH/FSH, TT, insulin, SHBG and HOMA-IR were significantly higher in the study group. Among the nine tested variants of VEGF SNPs, two SNPs rs3025020 and rs833061, consisted of TT (Recessive and Dominant homozygous, respectively) which were marginally higher in test. The SNP rs1570360 had significantly higher GG allele (32.73%) which was recessive homozygous. There was no significant difference observed in genotype frequencies related to higher value of VEGF. The genotype frequencies for the studied SNPs were in alignment with Hardy-Weinberg equilibrium (HWE). The mean serum VEGF levels got significantly increased in PCOS group. No significant association was found between VEGF genotypes and its serum levels. VEGF levels in rs699947 (AA-major homozygous), rs3025039 (CC-major homozygous) and rs833061 (TT & CC-major & minor homozygous) genotypes were significantly higher in PCOS. The study results evidently proved that the allelic variants in genes may be a factor for PCOS and VEGF serum levels with respect to few SNP variants only. These findings indicated that VEGF may be involved in PCOS status and confirmed the previous association between genetic variants in VEGF, serum level of VEGF protein and PCOS.

VEGF gene polymorphism interactions with dietary trace elements intake in determining the risk of metabolic syndrome.

There is a complex association among genetic, metabolic, and environmental factors in determining the risk of metabolic syndrome (MetS). The aim of this study was to investigate the role of the association between the dietary intake of iron, copper, zinc, manganese, selenium, and iodine (assessed by 24 recall) with vascular endothelial growth factor variants (rs6921438, rs4416670, rs6993770, and rs10738760), on the risk of MetS. Two-hundred and forty-eight individuals with MetS and 100 individuals without MetS were recruited. The dietary intake and the daily average of energy and nutrient intake were obtained by a questionnaire and quantified using Diet Plan 6 software. DNA was extracted from EDTA anticoagulated whole blood. The SNPs were assessed using using a Sequenom iPLEX Gold assay. Data analysis was undertaken using the Student t test, χ2 test and logistic regression using SPSS 11.5 software. There was a significant association between low dietary iron intake and rs6993770 (β = .10, P < .05), and a low dietary zinc and a high manganese intake with rs6921438 in relation to the presence of MetS (β = -.17, P < .05, β = -.30, P < .05, respectively). Our data showed the association of rs6993770 with iron intake and rs6921438 with zinc and manganese intake, indicating further investigation in a larger population to evaluate their values.

Novel engineered, membrane-localized variants of vascular endothelial growth factor (VEGF) protect retinal ganglion cells: a proof-of-concept study

Endogenous vascular endothelial growth factor (VEGF-A) can protect retinal ganglion cells (RGC) from stress-induced cell death in ocular hypertensive glaucoma. To exploit the neuroprotective function of VEGF-A for therapeutic application in ocular disorders such as glaucoma while minimizing unwanted vascular side effects, we engineered two novel VEGF variants, eVEGF-38 and eVEGF-53. These variants of the diffusible VEGF-A isoform VEGF121 are expressed as dimeric concatamers and remain tethered to the cell membrane, thus restricting the effects of the engineered VEGF to the cells expressing the protein. For comparison, we tested a Myc-tagged version of VEGF189, an isoform that binds tightly to the extracellular matrix and heparan sulfate proteoglycans at the cell surface, supporting only autocrine and localized juxtacrine signaling. In human retinal endothelial cells (hREC), expression of eVEGF-38, eVEGF-53, or VEGF189 increased VEGFR2 phosphorylation without increasing expression of pro-inflammatory markers, relative to VEGF165 protein and vector controls. AAV2-mediated transduction of eVEGF-38, eVEGF-53, or VEGF189 into primary mouse RGC promoted synaptogenesis and increased the average total length of neurites and axons per RGC by ~ 12-fold, an increase that was mediated by VEGFR2 and PI3K/AKT signaling. Expression of eVEGF-38 in primary RGC enhanced expression of genes associated with neuritogenesis, axon outgrowth, axon guidance, and cell survival. Transduction of primary RGC with any of the membrane-associated VEGF constructs increased survival both under normal culture conditions and in the presence of the cytotoxic chemicals H2O2 (via VEGFR2/PI3K/AKT signaling) and N-methyl-d-aspartate (via reduced Ca2+ influx). Moreover, RGC number was increased in mouse embryonic stem cell-derived retinal organoid cultures transduced with the eVEGF-53 construct. The novel, engineered VEGF variants eVEGF-38 and eVEGF-53 show promise as potential therapeutics for retinal RGC neuroprotection when delivered using a gene therapy approach.

Expression of VEGF₁₆₅b, VEGFR1, VEGFR2 and CD34 in benign and malignant tumors of parotid glands.

Vascular endothelial growth factor (VEGF) is an angiogenic factor and could be involved in the pathogenesis of salivary gland tumors. VEGF exerts its biological function by binding to its receptors, VEGFR1 and VEGFR2. An alternative splice variant of VEGF (VEGFxxxb) is an anti-angiogenic factor. Binding VEGF165b with VEGFR2 results in an impaired angiogenic response. The imbalance of VEGFxxx and VEGFxxxb isoforms can underpin pathological angiogenesis. The purpose of this study was to evaluate and compare the expression of VEGF165b, VEGFR1, VEGFR2, and CD34 in benign and malignant parotid gland tumors and to explore the possible correlations between their expression and clinicopathological features of tumors. The study was performed on archived paraffin-embedded tissue samples derived from 70 patients with benign and malignant parotid gland tumors (25 with malignant tumors, 23 with pleomorphic adenoma and 22 with Warthin's tumor). Immunohistochemical staining of selected tissue sections was performed using monoclonal antibodies. Immunohistochemical staining of selected molecules was used for evaluation of their expression in tissue sections. There were no statistically significant differences in the expression of the selected proteins localized in the tumor and surgical margin taken from the same patient. Expression of VEGFR2 correlated with VEGF165b in mixed tumors. There was a statistically significant difference in the expression of VEGFR1 in malignant tumors between females and males, and between the expression of VEGFR1 and the score of T classification in malignant tumors. VEGF165b cannot be treated as a prognostic factor. VEGF receptors correlated with selected clinicopathological data of malignant tumors, indicating their possible role as a prognostic marker. The balance of VEGF isoforms have a limited influence on the development of parotid glands tumors. The correlation between VEGF165b and VEGFR2 in mixed tumors suggests the existence of an additional antiangiogenic pathway in poorly vascularized mixed tumors.

Real-time analysis of the binding of fluorescent VEGF165a to VEGFR2 in living cells: Effect of receptor tyrosine kinase inhibitors and fate of internalized agonist-receptor complexes

Vascular endothelial growth factor (VEGF) is an important mediator of angiogenesis. Here we have used a novel stoichiometric protein-labeling method to generate a fluorescent variant of VEGF (VEGF165a-TMR) labeled on a single cysteine within each protomer of the antiparallel VEGF homodimer. VEGF165a-TMR has then been used in conjunction with full length VEGFR2, tagged with the bioluminescent protein NanoLuc, to undertake a real time quantitative evaluation of VEGFR2 binding characteristics in living cells using bioluminescence resonance energy transfer (BRET). This provided quantitative information on VEGF-VEGFR2 interactions. At longer incubation times, VEGFR2 is internalized by VEGF165a-TMR into intracellular endosomes. This internalization can be prevented by the receptor tyrosine kinase inhibitors (RTKIs) cediranib, sorafenib, pazopanib or vandetanib. In the absence of RTKIs, the BRET signal is decreased over time as a consequence of the dissociation of agonist from the receptor in intracellular endosomes and recycling of VEGFR2 back to the plasma membrane.

Association between levels of anti-angiogenic isoform of vascular endothelial growth factor A and pulmonary hypertension

BackgroundsPulmonary hypertension (PH) is characterized by elevated pulmonary arterial pressure due to vasoconstriction and remodeling of the pulmonary microvasculature. Vascular endothelial growth factor (VEGF) is a key contributor for angiogenesis and vasculogenesis. VEGF165b is recently identified as an anti-angiogenic splicing variant of VEGF. The aim of this study was to examine the association between circulating levels of VEGF165b in PH patients under consideration with classifications of PH. Methods and resultsWe measured plasma levels of VEGF165b in the PH group (pulmonary artery hypertension [PAH], n=26; chronic thromboembolic pulmonary hypertension [CTEPH], n=13) and control group (n=30). Circulating levels of VEGF165b were higher in PH group than controls (97.1 vs. 53.3pg/ml, P<0.01). The multiple regression analysis demonstrated that the independent factor to determine the plasma levels of VEGF165b was the presence of PH (P=0.04). Next, we focused on differences in VEGF165b levels and classifications of PH. Plasma VEGF165b level was higher only in idiopathic PAH (n=9) than in control (137.1 vs. 53.3pg/ml, P<0.01), but not in PH related to collagen disease (n=7), congenital heart disease (n=10) and CTEPH (n=13). ConclusionsWe demonstrated associations between circulating levels of VEGF165b and classifications of PH. VEGF165b, anti-angiogenic isoform, might contribute to the pathophysiology in PH, especially in idiopathic PAH. The level of plasma VEGF165b might be a novel marker that reflects the pathological conditions in patients with PH.

Genetic variants of vascular endothelial growth factor are associated with recurrent implantation failure in Korean women

Vascular endothelial growth factor (VEGF) is involved in embryonic development, decidual vascularization and placenta angiogenesis. This study was performed to determine whether there is an association between genetic polymorphisms in the VEGF gene and the development of recurrent implantation failure (RIF) in Korean women. A total of 119 women diagnosed with RIF and 236 control subjects were genotyped for VEGF polymorphic sites including rs833061 (-460T>C), rs25648 (-7C>T) and rs3025020 (-583C>T) using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) assays and real-time PCR. The VEGF rs833061 C allele and rs25648 T allele were significantly associated with increased RIF risk (odds ratio [OR] = 1.813 [1.161–2.831], P = 0.009, OR = 2.213 [1.254–3.903], P = 0.005). The rs833061/rs25648 TC/CT, TC/CT+TT, and rs833061/rs3025020 TC+CC/TT genotypes were more frequent in the RIF group compared with the control group (OR = 2.130 [1.092–4.156], P = 0.025, OR = 2.130 [1.092–4.156], OR = 4.261 [1.163–15.620], P = 0.028, respectively). The results of this study suggests that VEGF polymorphisms are associated with RIF development. Therefore, we postulate that VEGF polymorphisms might be useful markers to predict RIF development. Further studies are warranted to elucidate the role of VEGF variants and RIF development.

Genetic Variants of VEGF (rs201963 and rs3025039) and KDR (rs7667298, rs2305948, and rs1870377) Are Associated with Glioma Risk in a Han Chinese Population: a Case-Control Study.

A glioma is the most common type of brain tumor that accounts for nearly 80 % of brain cancers. Vascular endothelial growth factor (VEGF) and its receptor, the kinase insert domain receptor (KDR), are involved in the angiogenesis of cancers. In this study, we investigate whether the polymorphisms of VEGF and KDR are associated with a glioma risk. Blood samples were collected from 477 glioma patients and 477 healthy controls. Five tag-single nucleotide polymorphisms (SNPs) of KDR were obtained from the HapMap database, and eight tag-SNPs of VEGF were selected based on previous studies. After extraction of genomic DNAs by a Qiagen DNA blood kit, the SNPs of VEGF and KDR were genotyped with a Sequenom MassArray iPLEX platform and further analyzed with matrix-assisted laser desorption ionization time-of-flight (MALDI-TOF) mass spectrometry. The odds ratios and their 95% confidence interval (95% CI) were used to assess the association between VEGF, KDR polymorphisms, and glioma risks with the aid of SPSS 13.0 software. The haplotype analysis demonstrated that two SNPs of VEGF [rs3025039 (C>T), rs2010963 (G>C)] could elevate the susceptibility to a glioma in the homozygous model [odds ratio (OR) = 3.13 (95% confidence interval (CI) 1.30-7.49, P = 0.007) and OR = 1.58 (95% CI 1.07-2.34, P = 0.022), respectively], dominant model [OR = 1.38 (95% CI 1.04-1.84, P = 0.025) and OR = 1.32 (95% CI 1.01-1.72, P = 0.043), respectively], and allelic model [OR = 1.43 (95% CI 1.11-1.84, P = 0.005) and OR = 1.24 (95% CI 1.04-1.50, P = 0.019), respectively]. Furthermore, three SNPs of KDR [rs7667298 (A>G), rs2305948 (C>T), rs1870377 (T>A)] were also assumed to be associated with an increased risk of a glioma in the homozygous [OR = 1.93 (95% CI 1.30-2.86, P = 0.001), OR = 2.56 (95% CI 1.28-5.11, P = 0.006), and OR = 1.52 (95% CI 1.00-2.31, P = 0.049), respectively], dominant [OR = 1.52 (95% CI 1.16-1.98, P = 0.002), OR = 1.41 (95% CI 1.05-1.87, P = 0.020), and OR = 1.48 (95% CI 1.13-1.93, P = 0.004), respectively], and allele models [OR = 1.39 (95% CI 1.15-1.67, P = 0.001), OR = 1.47 (95% CI 1.14-1.89, P = 0.002), and OR = 1.27 (95% CI 1.05-1.52, P = 0.013), respectively]. The genetic polymorphisms of VEGF [rs3025039 (C>T), rs2010963 (G>C)] and KDR [rs7667298 (A>G), rs2305948 (C>T), rs1870377 (T>A)] increased glioma susceptibility in a Chinese population, suggesting the possibility of VEGF and KDR as genetic markers for glioma. Additional functional and association studies with different ethnic groups included are needed to further confirm our results.

Genetic variations of VEGF gene were associated with tetralogy of fallot risk in a Chinese Han population.

Tetralogy of Fallot (TOF) is one of the most common forms of congenital heart disease. In this study, we aimed at investigating the associations between genetic variations of vascular endothelial growth factor (VEGF) gene and the risk of TOF in a Chinese Han population. Our findings may contribute to a deeper understanding of TOF pathogenesis and better diagnostic and therapeutic suggestions. A total of 165 TOF patients and 240 controls from a Chinese Han population in Shenyang and Harbin were recruited in the current study. Nine single-nucleotide polymorphisms (SNPs) (-2578C/A, -460T/C, -1154G/A, -634G/C, 534C/T, +398G/A, +963C/T, 752C/T, 913G/A) were genotyped by the MALDI-TOF MassARRAY system. Individual SNPs as well as their haplotypes were analyzed for their associations with TOF risk, using odds ratios and the 95% confidence interval under codominant and dominant models. In the single SNP analyses, the mutant homozygous genotypes of -2578C/A (rs699947) and +963C/T (rs3025039) were related with an increased risk of TOF. In addition, carriers with the mutant A allele of -1154G/A (rs1570360) were supposed to have a significantly elevated TOF risk. Similarly, compared with the wild homozygote GG carriers, the GC carrier of -634G/C (rs2010963) revealed a significant relationship with susceptibility of TOF, but not for the mutant homozygote CC carriers. However, no significant association was found for the other five SNPs. Meanwhile, haplotype analysis revealed that CCA and ATA in block 1 (-2578C/A, -460T/C, and -1154G/A) and TTG and TCA in block 3 (+963C/T, 752C/T, and 913G/A) were significantly related with an increased TOF risk compared with the most common haplotypes. In summary, our results suggested that VEGF variants (-2578C/A, -1154G/A, -634G/C, +963G/A) were involved in the susceptibility of TOF. However, validation of our study needs further study in various ethnics to reveal the functional relationship between VEGF polymorphisms and TOF risk, which may contribute to diagnosis and therapy of TOF.

Response to letter to the Editor from Dr. Carbillon on our article about first pregnancy characteristics, genetics, and breast density

My co-authors and I would like to thank Dr. Carbillon for his comments on our article about first pregnancy characteristics, genetics, and breast density. We found a modification in the association between pregnancy induced hypertension (PIH) and breast density (measured as percent fibroglandular volume, or %FGV) by specific vascular endothelial growth factor (VEGF) (rs3025039) and insulinlike growth factor receptor-1 (IGFR1) (rs2016347) gene variants. We appreciate the additional detail Dr. Carbillon added to the discussion of PIH, VEGF, and the risk of breast cancer. The various lines of evidence pointing to the potential role of VEGF and an elevated anti-angiogenic response in the pathophysiology of breast cancer merit additional focused research. Replication of our findings of an interaction between inherited IGFR and VEGF gene variants in other populations would bolster confidence in the overall association, and indeed such studies are being planned. In addition, molecular studies examining the distribution of VEGF and IGFR1 gene variants associated with protein expression levels in women with a known history of PIH, prior breast density measurements, and subsequent diagnosis of specific breast cancer subtypes would be most informative and would help further advance our understanding of the mechanistic interaction of these risk factors.