Vascular endothelial growth factor genetic variability and coronary artery disease in Brazilian population

Genetic polymorphisms in VEGFA and VEGFR2 genes associated with coronary heart disease susceptibility and severity

BACKGROUND

​Vascular endothelial growth factor A (VEGFA) is well acknowledged as a powerful angiogenesis-promoting agent mainly through its receptor VEGFR2. Ischemia stimulates VEGFA/VEGFR2 signaling pathway and elevated serum levels of VEGFA were detected in coronary heart disease (CHD) patients. The goal of the current study is to determine how four SNPs in the genes for VEGFA (rs3025039 and rs699947) and VEGFR2 (rs2305948 and rs1870377) contribute to the development of CHD. We also wanted to use the Gensini score to confirm if these four SNPs have an effect on the severity of coronary lesions.

METHODS

In this case-control research, we used the restriction fragment length polymorphism of the polymerase chain reaction to genotype 239 CHD patients and 200 controls. Age, sex, smoking behavior, and obesity were taken into account in the statistical analysis.

RESULTS

Two VEGFA/VEFGR2 signaling pathway SNPs (rs699947 and rs1870377) were found to be associated with CHD (C vs. A, P = 0.002; OR = 1.47 (1.12-1.93); A vs. T, P = 0.001; OR = 1.58 (1.17-2.13) respectively). The rs2305948 showed no allelic associations with CHD susceptibility, although we noticed a slight association under the recessive model of rs3025039 TT genotype (p = 0.023; OR = 6.41 (1.14-36.12)) only under adjusted analyses. In addition, both VEGFA SNPs (rs699947and rs3025039) were found to be associated with high Gensini score (p < 0.001).

CONCLUSIONS

Our research helps to shed further light on the pathophysiology of CHD. The VEGFA/VEGFR2 signaling pathway may have been downregulated, increasing CHD susceptibility and risk.

VEGF gene polymorphism in complicated infective endocarditis

Introduction. Infective endocarditis (IE) is a bacterial disease with frequent pathogen localization on the heart valve apparatus. IE is characterized by rapid development of heart failure and frequent thromboembolic complications (TEC). IE features are accounted for by foreign pathogen nature and state of human immune system (IS). The imbalanced IS in infective endocarditis is manifested by impaired cytokine-mediated interactions. This confirms the rationality of studying cytokines to advance understanding of the pathogenesis for various conditions. Most cytokine genes are characterized by polymorphism and existing isoforms underlying disease predisposition. Genetic polymorphism of vascular endothelial growth factor A (VEGF-A) plays an important role in the induction of vasculogenesis and angiogenesis. The pathogenetic VEGF role in IE has not been thoroughly studied. Research objective analysis of polymorphic nucleotide sequence variants in the vascular endothelial growth factor gene, taking into account a relation with its serum concentration in patients with infective endocarditis. Materials and methods. 86 patients treated with verified diagnosis of infective endocarditis at the Scientific Research Institute Regional Clinical Hospital No. 1 of Krasnodar were divided into two clinical groups in accordance with the IE course: Group 1 IE with TEC (n = 44), group 2 IE without TEC (n = 42), and the control group consisted of 20 apparently healthy individuals. The concentration of serum VEGF-A (pg/mL) was measured by ELISA on day 1 of hospitalization. Genomic DNA was isolated from whole blood leukocytes and used to determine the frequency of genotypes of VEGF gene polymorphic variants. Results. Significant differences in the frequency distribution of VEGF-rs2010963 genotypes between patients with infective endocarditis and control group were revealed: G/G (OR = 0.25; p = 0.012) and G/C (OR = 4.28; p = 0.022), as well as differences between VEGF concentrations for various SNP-rs2010963 genotypes (p = 0.0001). A study of VEGF genotype frequency distribution between patients of clinical groups showed a significantly decreased frequency of the genotype G/G (rs2010963) in the IE group with TEC (OR = 0.21; p = 0.014) and increased frequency of G/C (OR = 4.72; p = 0.024) compared with the control group, whereas in patients with IE without TEC, significant (p = 0.0003) differences in serum concentrations of VEGF-rs2010963 were found in accordance with genotypes GG/CC (p = 0.01) and GG/GC (p = 0.003). Conclusion. The relationship between the VEGF genotypes (G/G and G/C of rs2010963 polymorphism) and related serum concentration among patients with IE was revealed. Carriers of the minor C allele (rs2010963) had higher serum VEGF levels. The results obtained complement and systematize current scientific data on the disease pathogenesis, as well as focus on the genetic determinant of the developing complications.

Association of genetic polymorphisms in vascular endothelial growth factor with susceptibility to coronary artery disease: a meta-analysis

Background

Single nucleotide polymorphisms (SNPs) located in the vascular endothelial growth factor (VEGF) gene may be correlated with the susceptibility to coronary artery disease (CAD) – although results have been controversial. The aim of this meta–analysis is to clarify the effects of VEGF –2578A/C (rs699947), −1154G/A (rs1570360), +405C/G (rs2010963), and + 936C/T (rs3025039) polymorphisms on CAD risk.

Methods

Pooled odds ratio (OR) and corresponding 95% confidence intervals (CIs) were calculated to estimate the strength of the association between VEGF gene polymorphisms and CAD risk. Fixed- or random-effects model was used depending on the heterogeneity between studies.

Results

In total, 13 eligible articles containing 29 studies were analysed. The pooled analysis indicated that the VEGF gene polymorphisms of rs699947, rs2010963, and rs3025039 were associated with an increased risk of CAD, whereas no significant associations were observed with the rs1570360 polymorphism. A subgroup analysis stratified by ethnicity revealed that the rs699947 and rs3025039 polymorphisms were associated with CAD risk in Asian populations. In addition, stratification by control source indicated an increased risk of CAD susceptibility with the rs699947 polymorphism for population–based studies of reduced heterogeneity.

Conclusions

In summary, we concluded that the VEGF gene polymorphisms rs699947, rs2010963, and rs3025039 are correlated with an elevated CAD risk.

Electronic supplementary material

The online version of this article (10.1186/s12881-018-0628-3) contains supplementary material, which is available to authorized users.

Vascular endothelial growth factor A polymorphisms are associated with increased risk of coronary heart disease: a meta-analysis

Coronary heart disease (CHD) is a common complex disease resulting from the interaction of multiple environmental and genetic factors. To assess the potential relationship of vascular endothelial growth factor (VEGFA) rs699947 C>A, rs3025039 C>T and rs2010963 G>C polymorphisms with CHD risk, a comprehensive meta-analysis was conducted. A systematic search of EMBASE and PubMed online database for publications on VEGFA polymorphisms and risk of CHD was carried out. Crude Odds ratios (ORs) with their 95% confidence intervals (CIs) were calculated to determine the association. A total of ten publications including 22 trails involving 2097 cases and 2867 controls were included in our pooled analysis. Overall, results of the present meta-analysis demonstrated a significant association between VEGFA rs699947 C>A polymorphism and an increased risk of CHD. After stratifying by ethnicity and CHD type, the association was also obtained. A significant association between VEGFA rs3025039 C>T polymorphism and risk of CHD was also found. For VEGFA rs2010963 G>C polymorphism, the polymorphism was associated with MI risk. In conclusion, our findings suggest that VEGFA rs699947 C>A, rs3025039 C>T and rs2010963 G>C polymorphisms are risk factors for CHD. In the future, large sample size and well-designed epidemiologic studies are needed to confirm these conclusions.

Genetic and ethnic modulation of cardiovascular toxicity of vascular endothelial growth factor inhibitors

Vascular endothelial growth factor (VEGF) inhibitors, including monoclonal antibodies and tyrosine kinase inhibitors (TKIs), are important as anticancer treatments through curbing tumour angiogenesis and growth. VEGF inhibitors have significant cardiovascular effects. By blocking VEGF receptors, ligands, or signal pathways, VEGF inhibitors disturb the balance between vasodilation and vasoconstriction, undermine endothelial cell integrity, and activate cardiomyocyte apoptosis. VEGF inhibitors increase risks of hypertension, heart failure, thromboembolism and arrhythmia. Genetic and geographic studies showed that genetic polymorphisms likely play significant predictive or prognostic roles in cardiovascular toxicity associated with VEGF inhibitors. This review updates current understandings of VEGF inhibitors on cardiovascular toxicity, explores potential mechanisms, and clarifies whether genetic or ethnic factors contribute to their adverse effects. Key Messages VEGF inhibitors disturb the balance between vasodilation and vasoconstriction, undermine endothelial cell integrity and activate cardiomyocyte apoptosis. VEGF inhibitors increase risks of hypertension, heart failure, thromboembolism and arrhythmia. Genetic and geographic studies showed that genetic polymorphisms likely play significant predictive or prognostic roles in cardiovascular toxicity associated with VEGF inhibitors.

Cytosolic aminoacyl-tRNA synthetases: Unanticipated relocations for unexpected functions

Prokaryotic and eukaryotic cytosolic aminoacyl-tRNA synthetases (aaRSs) are essentially known for their conventional function of generating the full set of aminoacyl-tRNA species that are needed to incorporate each organism's repertoire of genetically-encoded amino acids during ribosomal translation of messenger RNAs. However, bacterial and eukaryotic cytosolic aaRSs have been shown to exhibit other essential nonconventional functions. Here we review all the subcellular compartments that prokaryotic and eukaryotic cytosolic aaRSs can reach to exert either a conventional or nontranslational role. We describe the physiological and stress conditions, the mechanisms and the signaling pathways that trigger their relocation and the new functions associated with these relocating cytosolic aaRS. Finally, given that these relocating pools of cytosolic aaRSs participate to a wide range of cellular pathways beyond translation, but equally important for cellular homeostasis, we mention some of the pathologies and diseases associated with the dis-regulation or malfunctioning of these nontranslational functions.

The impact of vascular endothelial growth factor +405 C/G polymorphism on long-term outcome and severity of coronary artery disease

BACKGROUND

The association between genetic variations of vascular endothelial growth factor (VEGF) gene and the risk for atherosclerosis has been hypothesized. We aimed to assess the relationship between rs2010963 (+405 C/G) polymorphism and presence, severity, and outcome of coronary artery disease (CAD) in an Iranian cohort.

METHODS

Genotyping of VEGF rs2010963 polymorphism was performed on 520 individuals, comprising 347 patients with documented coronary artery disease based on angiography report and 173 individuals with normal coronary arteries, using the TaqMan real-time PCR method. In final, 484 subjects were followed up over a 5-year period for cardiovascular-related outcomes.

RESULTS

C allele of VEGF rs2010963 polymorphism was related to increase risk for CAD and also slightly to 5-year cardiovascular mortality. The 5-year survival in C and G allele subgroups were 92.3% and 94.3% in CAD group and 95.7% and 98.0% in non-CAD group, respectively.

CONCLUSIONS

Vascular endothelial growth factor rs2010963 polymorphism may be associated with the presence of CAD and its long-term survival, but not with its severity. To the best of our knowledge, this is the first report of genetic association between rs2010963 SNP and CAD-related death. It can be thus suggested that rs2010963 VEGF gene can be considered as a genetic risk predictor for CAD and its outcomes.

Association of Genetic Polymorphisms on VEGFA and VEGFR2 With Risk of Coronary Heart Disease

Coronary heart disease (CHD) is a cardiovascular disease which is contributed by abnormal neovascularization. VEGFA (vascular endothelial growth factor A) and VEGFR2 (vascular endothelial growth factor receptor 2) have been revealed to be involved in the pathological angiogenesis. This study was intended to confirm whether single nucleotide polymorphisms (SNPs) of VEGFA and VEGFR2 were associated with CHD in a Chinese population, considering pathological features and living habits of CHD patients.Peripheral blood samples were collected from 810 CHD patients and 805 healthy individuals. Six tag SNPs within VEGFA and VEGFR2 were obtained from HapMap Database. Genotyping of SNPs was performed using SNapShot method (Applied Biosystems, Foster, CA). Odd ratios (ORs) and their 95% confidence intervals (95% CIs) were calculated to evaluate the association between SNPs and CHD risk.Under the allelic model, 6 SNPs of VEGFA and VEGFR2 were remarkably associated with the susceptibility to CHD. Genotype CT of rs3025039, TT of rs2305948, and AA of rs1873077 were associated with a reduced risk of CHD when smoking, alcohol intake and diabetes were considered, while homozygote GG of rs1570360 might elevate the susceptibility to CHD (all P < 0.05) for patients who were addicted to smoking or those with hypertension. All of the combined effects of rs699947 (CC/CA) and rs2305948 (TT), rs3025039 (TT) and rs2305948 (TT), rs3025039 (CT) and rs1870377 (AA) had positive effects on the risk of CHD, respectively (all P < 0.05). By contrast, the synthetic effects of rs69947 (CA/AA) and rs1870377 (TA), rs699947 (CA) and rs7667298 (GG), rs699947 (AA) and rs7667298 (GG), rs1570360 (GG) and rs2305948 (TT), as well as rs1570360 (GG) and rs1870377 (AA) all exhibited adverse effects on the risk of CHD, respectively (all P < 0.05).Six polymorphisms in VEGFA and VEGFR2 may have substantial influence on the susceptibility to CHD in a Han Chinese population. Prospective cohort studies should be further designed to confirm the above conclusions.

Candidate Gene Analysis of Mortality in Dialysis Patients

Background

Dialysis patients have high cardiovascular mortality risk. This study aimed to investigate the association between SNPs of genes involved in vascular processes and mortality in dialysis patients.

Methods

Forty two SNPs in 25 genes involved in endothelial function, vascular remodeling, cell proliferation, inflammation, coagulation and calcium/phosphate metabolism were genotyped in 1330 incident dialysis patients. The effect of SNPs on 5-years cardiovascular and non-cardiovascular mortality was investigated.

Results

The mortality rate was 114/1000 person-years and 49.4% of total mortality was cardiovascular. After correction for multiple testing, VEGF rs699947 was associated with all-cause mortality (HR1.48, 95% CI 1.14–1.92). The other SNPs were not associated with mortality.

Conclusions

This study provides further evidence that a SNP in the VEGF gene may contribute to the comorbid conditions of dialysis patients. Future studies should unravel the underlying mechanisms responsible for the increase in mortality in these patients.

Pharmacogenetics of erectile dysfunction: navigating into uncharted waters

Sildenafil and other PDE-5 inhibitors have revolutionized erectile dysfunction (ED) treatment. However, a significant number of patients do not respond or present adverse reactions to these drugs. While genetic polymorphisms may underlie this phenomenon, very little research has been undertaken in this research field. Most of the current knowledge is based on sildenafil, thus almost completely ignoring other important pharmacological therapies. Currently, the most promising genes with pharmacogenetic implications in ED are related to the nitric oxide and cGMP pathway, although other genes are likely to affect the responsiveness to treatment of ED. Nevertheless, the small number of studies available opens the possibility of further exploring other genes and phenotypes related to ED. This article provides a comprehensive overview of the genes being tested for their pharmacogenetic relevance in the therapy of ED.

The association between therapeutic outcomes and VEGF G-1154A and C-936T gene polymorphisms in patients with glomerulonephritis

BACKGROUND

In this present study, we aimed to investigate the association between therapeutic outcomes and vascular endothelial growth factor (VEGF) G-1154A and C-936T gene polymorphisms in patients with glomerulonephritis.

METHODS

Thirty-eight patients with glomerulonephritis diagnosed by renal biopsy were included to the study. All patients had proteinuria at least 1 gram (g)/day in urine analysis. At the end of a yearly therapy, patients with proteinuria less than 0.5 g/day were accepted as in complete remission and they were termed as group 1. The patients with proteinuria over 0.5 g/day were accepted as in no remission and they were termed as group 2.

RESULTS

The mean age of patients in group 1 and group 2 was 35.88 ± 13.80 years and 37.30 ± 13.89 years, respectively. There were nine (50%) male and nine (50%) female patients in group 1. In group 2, seven (35%) male and 13 (65%) female patients were present. Although VEGF G-1154A (GG) gene polymorphism was found in 55% of group 2 patients, and 22.2% of group 1 patients, but the differences did not reach statistical significance. There were no statistical differences between groups in terms of other gene polymorphisms. Namely, we obtained no statistical differences between therapeutic outcomes and gene polymorphisms.

CONCLUSIONS

There is a significant difference between groups in terms of VEGF G-1154A (GG) gene polymorphism, but the minority of the patient population has led to not to reach statistical significance. So, this gene polymorphism has to be investigated in larger studies.

Angiotensin converting enzyme insertion/deletion (I/D) (rs4646994) and Vegf polymorphism (+405G/C; rs2010963) in type II diabetic patients: Association with the risk of coronary artery disease

HYPOTHESIS

Little is known about the concomitant presence of the angiotensin-converting enzyme (ACE) (rs4646994) D allele and vascular endothelial growth factor(VEGF) (+405G/C; rs2010963) G allele on the susceptibility of coronary artery disease (CAD). Here we examined the hypothesis that ACE-D and VEGF-G alleles act synergistically to increase the severity of CAD in patients with type II diabetes mellitus (T2DM).

MATERIALS AND METHODS

The VEGF (rs2010963) and ACE (rs4646994) genotypes were detected by polymerase chain reaction - restriction fragment length polymorphism (PCR-RFLP) and PCR, respectively in 510 T2DM patients undergoing their first coronary angiography. Diabetic patients were classified as T2DM patients with and without CAD (control).

RESULTS

The crude odds ratio (OR) for the presence of CAD in ID+DD and D allele carriers were 1.98 (p=0.01) and 1.55 (p=0.001), respectively. Also, adjusted ORs in the presence of normolipidemia and the absence of history of hypertension for the risk of CAD in the either ACE(rs4646994) D allele or VGEF(rs2010963)-G alleles were 2.08 (p=0.004) and 1.75 (p=0.024), respectively. In addition, the concomitant presence of the ACE-D and VEGF-G alleles increased the risk of CAD 2.25-fold (p=0.043).

CONCLUSION

Our results indicated that ACE(rs4646994)-D allele alone and in the presence of VEGF(rs2010963)-G allele can be an important independent risk factor for susceptibility of CAD in T2DM patients even after correcting for conventional risk factors in a population of Iran.

VEGF, not VEGFR2, is associated with the angiogenesis effect of mini-TyrRS/mini-TrpRS in human umbilical vein endothelial cells in hypoxia

The purpose of this study was to determine the relationship between VEGF and mini-TyrRS/mini-TrpRS in angiogenesis in hypoxic culture and to begin to comprehend their mechanism in angiogenesis. We designed a VEGF gene silencing assay by using lentivirus vectors, and then western blotting was used to determine the protein expression of VEGF, VEGFR2 and pVEGFR2 in three groups in hypoxic culture at 3, 6, 12, or 24 h: (1) untransfected human umbilical vein endothelial cells (HUVECs) (Control); (2) pGCSIL-GFP lentivirus vector-transduced HUVECs (Mock); and (3) pGCSIL-shVEGF lentivirus vector-transduced HUVECs (Experimental). We also detected the effects of mini-TyrRS/mini-TrpRS peptides on HUVEC proliferation, migration and tube formation after lentivirus vector transfection and VEGFR2 antibody injection. The results indicated that expression of the mini-TyrRS protein was increased, whereas that of mini-TrpRS was specifically decreased in hypoxic culture both in control and mock groups. However, this trend in protein levels of mini-TyrRS and mini-TrpRS was lost in the experimental group after transduction with the pGCSIL-shVEGF lentivirus vector. The protein expression of VEGF was increased in hypoxic culture both in control and mock groups. After transduction with the pGCSIL-shVEGF lentivirus vector, the protein level of VEGF was noticeably decreased in the experimental group; however, for VEGFR2, the results showed no significant difference in VEGFR2 protein expression in any of the groups. For pVEGFR2, we found a distinct trend from that seen with VEGF. The protein expression of pVEGFR2 was sharply increased in hypoxic culture in the three groups. The addition of mini-TyrRS significantly promoted proliferation, migration and tube formation of HUVECs, while mini-TrpRS inhibited these processes in both control and mock groups in hypoxic culture. However, these effects disappeared after transduction with the pGCSIL-shVEGF lentivirus vector in the experimental group, but no significant difference was observed after VEGFR2 antibody injection. The protein expression of VEGF is similar to that of mini-TyrRS in hypoxic culture and plays an important role in the mini-TyrRS/mini-TrpRS-stimulated proliferation, migration and tube formation of HUVECs in hypoxia. These results also suggest that the change in mini-TyrRS and mini-TrpRS expression in hypoxic culture is not related to VEGFR2 and that some other possible mechanisms, are involved in the phosphorylation of VEGFR2.

Methionine sulfoxide reductase A rs10903323 G/A polymorphism is associated with increased risk of coronary artery disease in a Chinese population

OBJECTIVE

Coronary artery disease (CAD) is a complex disease resulting from a combination of environmental and genetic factors. We hypothesized that polymorphisms in methionine sulfoxide reductase A (MSRA: rs10903323 G/A) and vascular endothelial growth factor A (VEGFA: rs699947 C/A, rs2010963 G/C, and rs3025039 C/T) contribute to CAD susceptibility.

DESIGNS AND METHODS

We examined the association between the four polymorphisms and the risk of CAD in a Chinese population of 435 CAD patients and 480 controls. Genotyping was performed using matrix-assisted laser desorption ionization/time-of-flight mass spectrometry (MALDI/TOF-MS).

RESULTS

When the MSRA rs10903323 GG homozygous genotype was used as the reference group, the GA and GA/AA genotypes were associated with a significantly increased risk of CAD (GA vs GG: adjusted OR=1.36, 95% CI=1.02-1.82, p=0.038; GA/AA vs GG: adjusted OR=1.33, 95% CI=1.01-1.76, p=0.042). The AA homozygous genotype was not associated with a risk of CAD. In the recessive model, when the MSRA rs10903323 GG/GA genotypes were used as the reference group, the AA homozygous genotype was not associated with a risk of CAD. Logistic regression analyses revealed that the VEGFA rs699947 C/A, VEGFA rs2010963 G/C, and VEGFA rs3025039 C/T polymorphisms were not associated with a risk of CAD.

CONCLUSIONS

These findings suggest that the functional MSRA rs10903323 G/A polymorphism is associated with CAD development. However, our results allow only a preliminary conclusion, which must be validated with a larger study of a more diverse ethnic population.

Further evidence for the contribution of the vascular endothelial growth factor gene in coronary artery disease susceptibility

Coronary artery disease (CAD) receives intensive attentions in the research of cardiovascular diseases, due to its high incidence and severe impact on the quality of life vascular endothelial growth factor (VEGF), a potent angiogenic and vascular permeability factor, has been strongly implicated in the pathogenesis of CAD. Genetic markers in different regions of the VEGF gene have a plausible role in modulating the risk of CAD. To identify the markers contributing to the genetic susceptibility to CAD, we examined the potential association between CAD and 10 single nucleotide polymorphisms (SNPs, rs699947, rs1570360, rs2010963, rs833068, rs3024997, rs3025000, rs3025010, rs3025020, rs3025030, rs3025039) of the VEGF gene using the MassARRAY system. Participants included 242 CAD patients and 253 healthy controls from a Chinese Han Population (He'nan Province, China). The allelic or genotypic frequencies of the rs699947 (5' untranslated regions, 5'UTR) and rs2010963 (5'UTR) polymorphisms in the CAD patients were significantly different from those in the healthy controls. The CAD patients had significantly higher frequency of the rs699947 A allele (χ(2)=11.141, P=0.001, OR=1.665, 95% CI=1.232-2.250) and rs2010963 C allele (χ(2)=13.593, P=0.0002, OR=1.611, 95% CI=1.249-2.077). Strong linkage disequilibrium was observed in the rs699947-rs1570360-rs2010963 haplotype block (D'>0.9). Significantly more C-G-C haplotypes (P=0.040) and significantly fewer C-G-G haplotypes (P=0.0004) were found in the CAD patients. The possible association of rs699947 and rs2010963 with CAD risks warrant confirmation in independent case-control studies and may be informative for future investigations on the pathogenesis of CAD.

Impact of VEGF polymorphisms on the severity of peripheral artery disease in diabetic patients

OBJECTIVE

To determine the potential genotype vascular endothelial growth factor (VEGF) gene differences in diabetic patients with peripheral arterial disease (PAD), which might be associated with different stages of the vascular disease.

METHODS

A study was conducted with type 2 diabetic patients with PAD [n = 70; 32 intermittent claudication and 38 critical limb ischaemia (CLI)]. Genotyping of the VEGF gene insertion/deletion - 2549, - 2578 C/A and +405 G/C polymorphisms was done in both groups and correlated them with the severity of PAD. We compared serum VEGF levels in both groups.

RESULTS

There was a higher frequency of +405 CC and - 2578 CC genotypes in claudication group [(31.3% vs. 5.4%, p = 0.01) and (37.5% vs. 15.8%, p = 0.05), respectively]. The presence of +405 GG and - 2578 AA genotypes was more common among CLI patients [(57.8% vs. 37.5%, p = 0.01) and (42.1% vs. 18.8%, p = 0.05), respectively]. There were higher serum VEGF levels in patients with CLI (p = 0.029).

CONCLUSIONS

We found preliminary evidence regarding the association between VEGF polymorphisms and different stages of PAD in diabetic patients.

Polymorphisms in endothelial nitric oxide synthase (eNOS) and vascular endothelial growth factor (VEGF) predict sunitinib-induced hypertension

Hypertension is an important side effect of sunitinib treatment. In a retrospective study in 255 patients, single-nucleotide polymorphisms (SNPs) in vascular endothelial growth factor A (VEGFA), vascular endothelial growth factor receptor (VEGFR)-2, endothelin-1 (ET-1), and endothelium-derived nitric oxide synthase (eNOS) were multivariately tested against hypertension grades and changes in systolic blood pressure (SBP), diastolic BP (DBP), and mean arterial BP (MAP). Next, the association between hypertension and survival in patients with metastatic renal cell cancer (mRCC) was studied. Greater elevations in SBP and MAP were associated with the presence of a haplotype in VEGFA (P = 0.014 and P = 0.036, respectively). The tendency to develop grade 3 hypertension was associated with this haplotype and also with a SNP in eNOS (P = 0.031 and P = 0.045, respectively). In mRCC patients, sunitinib-induced hypertension was found to confer a survival benefit, with the mean overall survival being prolonged by 7.2 months (P = 0.035 and P = 0.026 for SBP and DBP elevations, respectively). Genetic polymorphisms in VEGFA and eNOS independently predict rise in BP and/or development of severe hypertension in sunitinib-treated patients. Grade 3 hypertension was found to be an independent factor for overall survival in patients with mRCC.

VEGF gene mRNA expression in patients with coronary artery disease

To assess the expression of vascular endothelium growth factor (VEGF) mRNA in unstimulated peripheral blood mononuclear cells of patients with and without coronary artery disease (CAD). We also studied whether the functional VEGF -2,578C/A polymorphism may influence the level of VEGF mRNA expression in individuals undergoing coronary angiography because chest pain. We assessed 50 consecutive patients with angiographically confirmed CAD (CAD+). Also, 50 consecutive individuals with normal coronary studies were included in the study for comparison. VEGF mRNA expression was examined using quantitative real-time PCR and genotyping for VEGF -2,578C/A was performed using ARMS-PCR technique. VEGF mRNA expression was significantly decreased in CAD+ patients when compared to CAD- individuals (p = 0.01). The frequency of VEGF -2578 allele C and genotype CC was increased in CAD+ patients. In this regard, homozygosity for the CC genotype was more commonly observed in CAD+ (30 %) than in those without CAD disease (18 %). However, the difference was slightly out of the range of significance (p = 0.1). In addition, a trend for reduction in the expression of VEGF mRNA was observed when patients carrying the VEGF -2,578AA genotype were compared with those VEGF -2,578AC heterozygous or those homozygous for the VEGF -2,578CC genotype. VEGF gene expression is decreased in individuals with CAD+ disease. The VEGF -2,578C/A polymorphism may influences the expression of VEGF.

Vascular endothelial growth factor polymorphisms are involved in the late vascular complications in Type II diabetic patients

AIM

To determine the potential genotype differences in the vascular endothelial growth factor (VEGF) gene in diabetic patients, which might explain the difference in terms of the development of clinical vascular complications: great vessels atherosclerosis vs. retinopathy.

METHODS

Genotyping of the VEFG gene insertion/deletion -2549, the C-2578A and the G+405C polymorphisms was done in 40 diabetic patients (26 with peripheral artery disease (PAD) and 14 with diabetic retinopathy (DR)).

RESULTS

There was a significant increase in the frequency of the VEGF -2549 DD genotype in PAD patients compared with the DR group (34.6 vs. 0; p = 0.016), as well as in the distribution of the VEGF -2549 ID genotype in DR compared with PAD patients (85.7 vs. 38.4; p = 0.005). There was a significant increase in the frequency of the VEGF -2578 CC genotype in the PAD group compared with DR (34.6 vs. 0; p = 0.016), as well as in the VEGF -2578 CA genotype in DR patients compared with PAD (85.7 vs. 34.6; p = 0.002). The VEGF +405 genotype was not associated with diabetic vascular complications.

CONCLUSION

This study provides preliminary evidence that VEGF polymorphisms are associated with a differential presentation of diabetic vascular complications.

Vascular endothelial growth factor haplotypes associated with childhood obesity

Expansion of adipose tissue in obesity is associated with angiogenesis and adipose tissue mass depends on neovascularization. Vascular endothelial growth factor (VEGF) is the main angiogenic factor in the adipose tissue, and VEGF expression is tightly regulated at both transcriptional and translational levels. However, no previous study has tested the hypothesis that genetic polymorphisms in the VEGF gene could affect susceptibility to obesity. To test this hypothesis, we compared the distribution of genotypes and haplotypes including three VEGF genetic polymorphisms in obese children and adolescents with those found in healthy controls. We studied 172 healthy children and adolescents and 113 obese children and adolescents. Genotypes of three clinically relevant VEGF polymorphisms in the promoter region (C-2578A, G-1154A, and G-634C) of the VEGF gene were determined by TaqMan allele discrimination assay and real-time polymerase chain reaction. VEGF haplotypes were inferred using Haplo.stats and PHASE 2.1 programs. We found no differences in the distributions of VEGF genotypes and alleles (p > 0.05). However, the CAG haplotype was more frequent in the obese group than in the control group (4% versus 0%, respectively, in white subjects; p = 0.008; odds ratio = 10.148 (95% confidence interval: 1.098-93.788). Our findings suggest that VEGF haplotypes affect susceptibility to obesity in children and adolescents.

Interaction between smoking and polymorphism in the promoter region of the VEGFA gene is associated with ischemic heart disease and myocardial infarction in rheumatoid arthritis

OBJECTIVE

To determine whether variants in the vascular endothelial growth factor A (VEGFA) gene are associated with ischemic heart disease (IHD) and/or myocardial infarction (MI) in patients with rheumatoid arthritis (RA), and whether there is evidence of a gene-smoking interaction.

METHODS

PCR-RFLP assays were used to determine the genotypes of VEGFA single-nucleotide polymorphisms (SNP) including VEGFA-2578A/C (rs699947), -460C/T (rs833061), +405C/G (rs2010963), and +936C/T (rs3025039) in 418 subjects with RA. Smoking history was obtained on each patient, and IHD and MI status was recorded. Associations with IHD/MI were assessed using contingency tables and logistic regression analyses.

RESULTS

Strong linkage disequilibrium was detected among VEGFA-2578, -460, and +405. SNP located in the VEGFA promoter region (-2578, -460) were found to be associated with IHD and MI, whereas +405 and +936, in the 5'-untranslated region (UTR) and 3'-UTR, respectively, were not. Haplotype analysis suggested that the A/C/G haplotype was associated with increased risk of IHD (OR 2.37, 95% CI 1.22-4.62) and MI (OR 4.10, 95% CI 1.45-11.49). Smoking was also independently associated with IHD and MI, and evidence of interaction between smoking and the VEGFA promoter SNP was found. Multivariate analyses indicated that the strongest associations with IHD and MI were due to the combined effect of the VEGFA-2578 A allele and smoking (OR 3.52 and 7.11, respectively), independent of risk factors such as age, sex, diabetes, C-reactive protein, hypercholesterolemia, and hypertension.

CONCLUSION

Interaction between smoking and polymorphism in the VEGFA gene is associated with IHD and MI in patients with RA.

Cell membrane stretch activates intermediate-conductance Ca2+-activated K+ channels in arterial smooth muscle cells

The aim of this study is to determine the signal transduction of membrane stretch on intermediate-conductance Ca(2+)-activated K(+) (IKca) channels in rat aorta smooth muscle cells using the patch-clamp technique. To stretch the cell membrane, both suction to the rear end of patch pipette and hypotonic shock were used. In cell-attached and inside-out patch configurations, the open probability of IKca channels increased when 20- to 45-mmHg suction was applied. Hyposmotic swelling efficiently increased IKca channel current. When the Ca(2+)-free solution was superfused, the activation of IKca current by the hyposmotic swelling was reduced. Furthermore, gadolinium (Gd(3+)) attenuated the activation of IKca channels induced by hyposmotic swelling, whereas nicardipine did not. In the experiments with Ca(2+)-free bath solution, pretreatment with GF109203X, a protein kinase C (PKC) inhibitor, completely abolished the stretch-induced activation of IKca currents. The stretch-induced activation of IKca channels was strongly inhibited by cytochalasin D, indicating a role for the F-actin in modulation of IKca channels by changes in cell stretching. These data suggest that cell membrane stretch activates IKca channels. In addition, the activation is associated with extracellular Ca(2+) influx through stretch-activated nonselective cation channels, and is also modulated by the F-actin cytoskeleton and the activation of PKC.

Cardiac autonomic functions derived from short-term heart rate variability recordings associated with heart rate recovery after treadmill exercise test in young individuals

Analysis of short-term heart rate variability (HRV) may provide useful information about autonomic nervous control of heart rate recovery. We studied 495 individuals (273 men), age range 19-85 years, submitted to treadmill exercise tests and short-term HRV evaluations over time (standard deviation of the normal-to-normal interval [SDNN], the square root of the mean squared differences of successive normal-to-normal intervals [RMSSD], the number of interval differences of successive normal-to-normal intervals greater than 50 ms [NN50 count], the proportion derived by dividing NN50 count by the total number of normal-to-normal intervals [pNN50]) and frequency (low-frequency power [LF], high-frequency power [HF], total power) domains. Among 495 patients, 106 patients (68 men) were elderly (age ≥ 65 years). Male gender and hypertension were significantly higher in elderly patients. The young patients had higher HRR after exercise. HRR at 4 min (54 ± 13 vs 60 ± 12 beats/min; P = 0.003) was the most significant predictor for positive exercise test result. In the young group, both time domain measures (SDNN: correlation coefficient 0.34, P < 0.001; RMSSD: correlation coefficient 0.37, P < 0.001) and frequency domain measures (LF: correlation coefficient 0.21, P < 0.001; HF: correlation coefficient 0.13, P = 0.01; total power: correlation coefficient 0.22, P < 0.001) were significantly associated with HRR at 4 min. HRR at 4 min was significantly associated with short-term HRV of time and frequency domains in young individuals, but not elderly ones, receiving treadmill exercise test.

Effect of mini-tyrosyl-tRNA synthetase/mini-tryptophanyl-tRNA synthetase on ischemic angiogenesis in rats: proliferation and migration of endothelial cells

The purpose of this study was to determine the mechanism of mini-tyrosyl-tRNA synthetase/mini-tryptophanyl-tRNA synthetase (mini-TyrRS/mini-TrpRS) on ischemic angiogenesis in rats with acute myocardial infarction and proliferation, migration, potential signaling pathways of rat coronary venular endothelial cells (RCVECs). The effects of mini-TyrRS/mini-TrpRS on RCVECs proliferation were evaluated using the MTT colorimetric assay. Cell migration was assayed using a modified Boyden chamber technique. The potential involvement of Erk and PI3K signaling pathways was explored using selective chemical inhibitor or Western-blot analysis. Left coronary artery ligation was used to establish the model of acute myocardial infarction in rats (Sprague-Dawley male rats, 200-250 g, 2-3 months old), 20 μl of mini-TyrRS, mini-TrpRS, or PBS (vehicle) was injected subcutaneously every 12 h. The rats were randomly divided into four experimental groups: sham operated group; coronary artery ligation (CAL); CAL + mini-TyrRS (20 μl, twice daily, 600 μg kg(-1) day(-1)); and CAL + mini-TrpRS (20 μl, twice daily, 600 μg kg(-1) day(-1)). The experiment was carried out at four time points on the 3rd, 7th, 14th, and 28th day after ligation. To determine whether mini-TyrRS/mini-TrpRS affected the angiogenesis activity of rats with myocardial infarction, we measured the myocardial infarction size by TTC staining, and microvessel density (MVD) was determined by CD34 staining. The results show that proliferation and migration in RCVECs could be promoted by mini-TyrRS at concentrations of 1-100 μg/ml, and inhibited by mini-TrpRS. Phospho-PI3-kinase and Erk expression increased significantly when mini-TyrRS was added, but could be attenuated by mini-TrpRS. Compared to the CAL group, the myocardial infarction size of the mini-TyrRS group at the 3rd, 7th, 14th, and 28th day were decreased, while mini-TrpRS increased, but only in days 14 and 28 was there a significant difference. Except that, the microvessel density of RCVECs was promoted in mini-TyrRS group but inhibited in the mini-TrpRS group. These results indicated that angiogenesis could be either stimulated by mini-TyrRS or inhibited by mini-TrpRS.

Vascular endothelial growth factor polymorphisms and extent of coronary atherosclerosis in Chinese population with advanced coronary artery disease

BACKGROUND

Vascular endothelial growth factor (VEGF) is important in atherosclerotic development. We examined two VEGF polymorphisms, including +405 C/G (rs2010963) and -2578C/A (rs699947), to assess their relation to the extent of coronary atherosclerosis.

METHODS

We recruited 398 patients with advanced coronary artery disease (CAD). Angiographic "clinical vessel score" (CVS, 1-3 vessels) and "diffuse score" (DS, 0-11.5) were used to evaluate the extent of coronary atherosclerosis. CVS are further categorized into single- (SVD) and multi-vessel disease (MVD: 2 and 3 vessels). Genotyping was performed by TaqMan assay.

RESULTS

The frequency of +405 C/G genotype was correlated with CVS and DS (P = 0.016 and 0.016, respectively). The +405C allele frequency was significantly increased in patients with MVD (P = 0.020). The odds ratio (OR) for the CC to the GG genotype was 2.92 (95% confidence interval (CI): 1.31-6.55, P = 0.007). Univariate and logistic regression analysis showed a significant independent association of +405 C/G genotype with SVD/MVD (P = 0.010 and 0.015, respectively) in the recessive model. Furthermore, there is a synergistic effect of CC genotype and diabetes on the occurrence of MVD (P = 0.001 for interaction). There is also a significant independent association of +405 C/G genotype in the recessive model with DS in the uni- and multivariate regression analysis (P = 0.013 and 0.005, respectively). No association was found between VEGF -2578C/A polymorphism and both atherosclerotic parameters.

CONCLUSIONS

The VEGF +405C/G polymorphism is a novel genetic factor to influence the extent of coronary atherosclerosis in the Chinese CAD population.

Two single nucleotide polymorphisms in ALOX15 are associated with risk of coronary artery disease in a Chinese Han population

Arachidonate 12/15-lipoxygenase (12/15-LOX) has been implicated in the pathogenesis of atherosclerosis, but with contradicting results. The aim of this study was to investigate the association of two polymorphisms in ALOX15 and the risk of coronary artery disease (CAD) in a Chinese Han population. A total of 519 unrelated CAD patients and 608 unrelated control subjects of the Chinese Han population were recruited in the case-control study. Two tagSNPs, rs7217186:T>C and rs2619112:G>A, were selected and genotyped by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). The carriers of the C allele (the CC homozygote and the CT heterozygote) of rs7217186:T>C and the carriers of the A allele (the AA homozygote and the GA heterozygote) of rs2619112:G>A displayed elevated odds ratios (ORs) for CAD compared with the TT homozygotes and GG homozygotes, respectively, after adjusting for other potential confounders including age, sex, body mass index, systolic blood pressure, diastolic blood pressure, glucose, triglyceride, total cholesterol, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, and smoking status (adjusted odds ratio [OR] = 3.2, 95% confidence interval [CI]: 1.335-7.665, P = 0.009 and adjusted OR = 3.5, 95% CI: 1.343-9.330, P = 0.011). In stratified analyses, after adjusting those aforementioned confounders, the CC and CT genotypes of rs7217186:T>C were associated with a greater risk of CAD in subjects <60 years (adjusted OR = 5.7, 95% CI: 1.557-21.097, P = 0.009) and in females (adjusted OR = 9.3, 95% CI: 1.048-82.213, P = 0.045). For rs2619112:G>A, subjects (<60 years) carrying the A allele had a greater risk of CAD than the GG homozygotes (adjusted OR = 4.9, 95% CI: 1.215-19.547, P = 0.025); the male carriers of A allele also had a greater risk (adjusted OR = 3.5, 95% CI: 1.136-11.006, P = 0.029). In summary, the present study shows that after adjustment for other confounding CAD factors, rs7217186:T>C and rs2619112:G>A of ALOX15 are associated with increased risk of CAD in this Chinese Han population.

Aquaporin-1 expression and angiogenesis in rabbit chronic myocardial ischemia is decreased by acetazolamide

Aquaporin-1 (AQP1) is a water channel protein expressed in endothelial and epithelial cells of many tissues, including the vasculature, where it serves to increase water permeability of the cell membrane. Prior studies have also reported that AQP1 plays a central role in tumor angiogenesis by promoting endothelial cell migration. To investigate whether AQP1 might also influence vascular angiogenesis in ischemic myocardium, the expression level of AQP1 for 21 days post myocardial infarction in rabbit hearts was observed. Aquaporin-1 mRNA and protein levels in day 3, and peaked on day 7 post surgery. This correlated well with the pattern of neovascularization and increased water content of infarct border tissue, and suggested that AQP1 may be involved in myocardial angiogenesis in response to ischemia injury. These AQP1-induced changes were tempered by acetazolamide, a carbonic anhydrase inhibitor, which acted by downregulating AQP1 expression. Acetazolamide treatment did not significantly affect the expression of vascular endothelial growth factor in the tissues studied. Our findings indicate a novel role for AQP1 in postnatal angiogenesis, which has implications in diverse pathophysiological conditions including wound healing, tumor metastasis, and organ regeneration.

Vascular endothelial growth factor increases human cardiac microvascular endothelial cell permeability to low-density lipoproteins

BACKGROUND

Endothelial cell hyperpermeability is a proposed mechanism of increased lipid insudation into the vessel walls of allografts. Vascular endothelial growth factor (VEGF) is a potent inducer of vascular permeability and its expression is upregulated in human heart allografts. The goal of these experiments was to investigate the effects of VEGF on low-density lipoprotein (LDL) permeability through confluent monolayers of human cardiac microvascular endothelial cells (HCMEC) in vitro.

METHODS

VEGF mRNA and protein expression was characterized in coronary arteries from cardiac allograft vasculopathy patients as compared with healthy controls using in situ hybridization and immunohistochemical staining of sub-adjacent sections. HCMEC were grown to confluence and treated with VEGF-A(121) or VEGF-A(165). Permeability of LDL in confluent endothelial monolayers was measured using fluorometry. Transendothelial electrical resistance (TER) measurements were used to indirectly measure the tight junctional status. Immunocytochemical staining was performed to visualize changes in CD31 and zonula occludens-1.

RESULTS

We observed significant increases in VEGF expression within the superficial and deep intima and media of coronaries from allografts, as compared with controls. In vitro treatment with VEGF-A(121) and VEGF-A(165) significantly increased LDL passage through endothelial monolayers. We further showed that VEGF-A(121) and VEGF-A(165) caused significant decreases in TER at 2 to 4 hours post-treatment. Also, VEGF induced disruption of tight junctions, resulting in an increase in the intercellular gap formation.

CONCLUSIONS

These results demonstrate that VEGF increases low-density lipoprotein permeability through endothelial monolayers, and this effect is correlated with VEGF-induced disruption of endothelial tight junctions resulting in the formation of intercellular gaps.