The relationship between vascular endothelial growth factor (VEGF) and microalbuminuria in patients with essential hypertension

A large-scale retrospective study of the overall survival outcome in nasopharyngeal carcinoma with hypertension in Chinese population

BACKGROUND

It is known that hypertension is associated with high levels of vascular endothelial growth factor (VEGF) expression which is, in turn, highly connected to the prognosis of a wide array of cancers. The purpose of this study was to evaluate the relationship between hypertension and prognosis of nasopharyngeal carcinoma (NPC) with definitive radiotherapy in a Chinese population.

PATIENTS AND METHODS

We retrospectively reviewed 4493 patients with NPC who received definitive radiotherapy from 1995 to 2006, with a minimum follow-up of 5 years. Kaplan-Meier survival analysis and Cox proportional hazard model were utilized to determine the association between hypertension and overall survival (OS).

RESULTS

A total of 802 patients with NPC suffered from hypertension as compared to 3691 patients with no associated hypertension. Kaplan-Meier analysis revealed median overall survival of 101.1 and 110.0 months, respectively (p<0.05). In univariate survival analysis, patients with hypertension had worse OS (p<0.05) than non-hypertension patients. Patients with higher grade hypertension also had worse OS (p<0.05) compare to patients with grade 1 hypertension. In multivariate survival analysis, patients with hypertension had significantly worse OS (p<0.05) than non-hypertension patients, as well as M stage (p<0.001), after adjustment for related clinical confounding factors.

CONCLUSION

Our findings provide evidence that hypertension is an independent factor and result in poorer survival outcomes in patients with NPC, the mechanism is still unclear, and it worth further research.

Novel marker for the detection of sickle cell nephropathy: soluble FMS-like tyrosine kinase-1 (sFLT-1)

BACKGROUND

Given the burden and poor outcome of end-stage renal disease in sickle cell disease (SCD), early markers of sickle cell nephropathy (SN) are desirable. Disordered angiogenesis underlies many complications of SCD. We aimed to determine the relationship between serum FMS-like tyrosine kinase-1 (sFLT-1) and other biomarkers of renal damage for the early diagnosis of SN.

METHODS

Forty-seven SCD patients and 49 healthy controls were enrolled. Microalbuminuria was determined in patient urine samples. Blood samples were tested for sFLT-1, serum creatinine, and various hemolysis and inflammation markers. Peripheral blood monocyte expression of sFLT-1 was measured using real-time polymerase chain reaction (PCR).

RESULTS

The serum level of sFLT-1 (pg/ml) in SCD patients was higher than controls (median/range/IQR = 142/ 60-1300/61 pg/ml vs. 125/ 110-187/52 pg/ml, respectively) (p = 0.006). Median (range) of sFLT-1 level was higher in SCD patients with microalbuminuria compared to SCD patients with normoalbuminuria, 185 (140-1300) vs. 125 (60-189) mg/g, respectively) (p = 0.004). There was a significant positive correlation between serum sFLT-1 and microalbuminuria, lactate dehydrogenase (LDH), and indirect bilirubin (r = 0.59, 0.39, 0.30, and p = <0.001, 0.007, 0.041, respectively). sFLT-1 sensitivity in early detection of renal affection in SCD was 93.6%, while specificity was 68.6%. Finally, peripheral blood monocytes (PBM) sFLT-1 expression was significantly higher in SCD patients compared to controls (p = 0.05).

CONCLUSIONS

sFLT-1 may contribute to pathogenesis of albuminuria in SCD patients and constitute a novel renal biomarker of SN.

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.

Association between circulating endostatin, hypertension duration, and hypertensive target-organ damage

Our aim is to study associations between circulating endostatin, hypertension duration, and hypertensive target-organ damage. Long-term hypertension induces cardiovascular and renal remodeling. Circulating endostatin, a biologically active derivate of collagen XVIII, has been suggested to be a relevant marker for extracellular matrix turnover and remodeling in various diseases. However, the role of endostatin in hypertension and hypertensive target-organ damage is unclear. Serum endostatin was measured in 2 independent community-based cohorts: the Prospective Investigation of the Vasculature in Uppsala Seniors (PIVUS; women 51%; n = 812; mean age, 75 years) and the Uppsala Longitudinal Study of Adult Men (ULSAM; n=785; mean age, 77.6 years). Retrospective data on blood pressure measurements and antihypertensive medication (PIVUS >5 years, ULSAM >27 years), and cross-sectional data on echocardiographic left ventricular mass, endothelial function (endothelium-dependent vasodilation assessed by the invasive forearm model), and urinary albumin/creatinine ratio were available. In PIVUS, participants with ≥ 5 years of history of hypertension portrayed 0.42 SD (95% confidence interval, 0.23-0.61; P<0.001) higher serum endostatin, compared with that of normotensives. This association was replicated in ULSAM, in which participants with 27 years hypertension duration had the highest endostatin (0.57 SD higher; 95% confidence interval, 0.35-0.80; P<0.001). In addition, higher endostatin was associated with higher left ventricular mass, worsened endothelial function, and higher urinary albumin/creatinine ratio (P<0.03 for all) in participants with prevalent hypertension. Circulating endostatin is associated with the duration of hypertension, and vascular, myocardial, and renal indices of hypertensive target-organ damage. Further studies are warranted to assess the prognostic role of endostatin in individuals with hypertension.

Impact of SHMT1 polymorphism on the clinical outcome of patients with metastatic colorectal cancer treated with first-line FOLFIRI+bevacizumab

The impact of thymidylate synthase (TYMS), methylenetetrahydrofolate reductase (MTHFR), and serine hydroxymethyltransferase 1 (SHMT1) gene polymorphisms and that of dihydropyrimidine dehydrogenase (DPD) enzyme activity, serum total homocysteine level, and estimated serum creatinine clearance on first-line 5-fluorouracil, leucovorin, irinotecan, and bevacizumab (FOLFIRI+bevacizumab) regimen efficacy in metastatic colorectal cancer patients was investigated. DNA was extracted from peripheral blood mononuclear cells. Genotyping was performed for TYMS 5'UTR variable number tandem repeat, TYMS 3'UTR ins/del, MTHFR C677T, and SHMT1 C1420T polymorphisms. The DPD activity of peripheral blood mononuclear cells was also determined. The univariate and multivariate analyses demonstrated that the SHMT1 1420T allele was associated with better response (P=0.025) and longer progression-free survival (PFS) (P=0.00004) and overall survival (OS) (P=0.034). Grade ≥2 hypertension was also an independent prognostic factor of longer progression-free survival and OS. Bevacizumab-related hypertension might be a predictive marker of treatment efficacy (P=0.0002 for OS) in the case of wild (CC) SHMT1 1420 genotypes only.

Functional VEGF haplotypes affect the susceptibility to hypertension

We examined whether vascular endothelial growth factor (VEGF) polymorphisms (C-2578A, G-1154A and G-634C) are associated with hypertension, response to antihypertensive therapy and nitric oxide (NO) formation. Substudy 1 compared the distribution of VEGF genotypes and haplotypes in 178 patients with arterial hypertension (100 whites and 78 blacks) and 186 healthy controls (115 whites and 71 blacks). Substudy 2 compared the distribution of VEGF markers in 82 patients with controlled hypertension, 89 patients with resistant hypertension and 101 normotensive (NT) patients. In substudy 3, plasma nitrite/nitrate (NOx) levels were determined (chemiluminescence assay) in 64 NT subjects and 48 hypertensive (HTN) subjects, and the distribution of VEGF markers was compared in subjects having low NOx with subjects having high NOx. Although the substudy 1 showed no differences in genotypes or allele distributions for the three VEGF polymorphisms between NT and HTN subjects, the 'C-A-G' haplotype was more common in white NT subjects than in the white HTN subjects, and the 'C-A-C' haplotype was more frequent in black and white HTN subjects than in black and white NT subjects. The substudy 2 showed similar results, with no differences between responsive and resistant HTN subjects. The substudy 3 showed that the 'C-A-G' haplotype, which had a protective effect against hypertension, was significantly more common in subjects with higher NOx concentrations than in subjects with lower NOx concentrations. VEGF haplotypes are associated with hypertension, and the haplotype associated with normotension was more common in subjects with increased NO formation, possibly offering a mechanistic clue for our findings.

Inhibition of glucose-induced vascular endothelial growth factor expression by Salvia miltiorrhiza hydrophilic extract in human microvascular endothelial cells: evidence for mitochondrial oxidative stress

AIM OF STUDY

Diabetes mellitus is frequently combined with vascular diseases, which are associated with the expression of vascular endothelial growth factor (VEGF). An approach that can reverse the induction of VEGF by hyperglycemia may potentially benefit the outcome of diabetic patients. Therefore, in the present study, we investigated the effect of Salvia miltiorrhiza (S. miltiorrhiza) hydrophilic extract on the expression of VEGF induced by high concentration of glucose.

MATERIALS AND METHODS

Vector of VEGF promoter luc was transiently transfected into HMEC-1 cells, and luciferase activity was measured to determine the promoter activity. In order to investigate the mechanism of Salvia miltiorrhiza hydrophilic extract, mitochondrial uncoupling protein 2(UCP2) was knockdown by using UCP2 siRNA. The expression of VEGF was obtained by using quantitative RT-PCR and dot blot. The level of reactive oxygen species (ROS) was expressed by the level of 2',7'-dichlorfluorescein.

RESULTS

Exposure of HMEC-1 cells to 30 mM glucose resulted in a significant increase in the expression of VEGF mRNA (5.7 fold at 3mM glucose, P<0.005), and an increase of ROS formation (2.4 fold at 3mM glucose, P<0.005). These effects were completely antagonized by an inhibitor of electron transport chain complex II, thenoyltrifluoroacetone (TTFA) and an uncoupler of oxidative phosphorylation, carbonylcyanide-m-chlorophenylhydrazone (CCCP). Addition of Salvia miltiorrhiza hydrophilic extract (10 μg/ml) led to a significant decrease of VEGF mRNA and ROS formation in 30 mM glucose condition. Interestingly, knockdown of mitochondrial UCP-2 by UCP-2 siRNA abolished the reduction of VEGF expression and ROS formation by Salvia miltiorrhiza hydrophilic extract.

CONCLUSIONS

These findings indicated that Salvia miltiorrhiza hydrophilic extract effectively reversed induction of VEGF expression by high glucose via ameliorating mitochondrial oxidative stress. Salvia miltiorrhiza hydrophilic extract can potentially be an effective antioxidant therapy for the treatment of diabetic chronic vascular complication.

Comorbidities of diabetes and hypertension: mechanisms and approach to target organ protection

Up to 75% of adults with diabetes also have hypertension, and patients with hypertension alone often show evidence of insulin resistance. Thus, hypertension and diabetes are common, intertwined conditions that share a significant overlap in underlying risk factors (including ethnicity, familial, dyslipidemia, and lifestyle determinants) and complications. These complications include microvascular and macrovascular disorders. The macrovascular complications, which are well recognized in patients with longstanding diabetes or hypertension, include coronary artery disease, myocardial infarction, stroke, congestive heart failure, and peripheral vascular disease. Although microvascular complications (retinopathy, nephropathy, and neuropathy) are conventionally linked to hyperglycemia, studies have shown that hypertension constitutes an important risk factor, especially for nephropathy. The familial predisposition to diabetes and hypertension appears to be polygenic in origin, which militates against the feasibility of a "gene therapy" approach to the control or prevention of these conditions. On the other hand, the shared lifestyle factors in the etiology of hypertension and diabetes provide ample opportunity for nonpharmacologic intervention. Thus, the initial approach to the management of both diabetes and hypertension must emphasize weight control, physical activity, and dietary modification. Interestingly, lifestyle intervention is remarkably effective in the primary prevention of diabetes and hypertension. These principles also are pertinent to the prevention of downstream macrovascular complications of the two disorders. In addition to lifestyle modification, most patients will require specific medications to achieve national treatment goals for hypertension and diabetes. Management of hyperglycemia, hypertension, dyslipidemia, and the underlying hypercoagulable and proinflammatory states requires the use of multiple medications in combination.

Gene polymorphism of vascular endothelial growth factor -1154 G>A is associated with hypertensive nephropathy in a Hispanic population

The aim of this study was to determine the association between hypertensive nephropathy and gene polymorphisms of vascular endothelial growth factor (VEGF) in a self-reported Hispanic patient group. A total of 155 Hispanic living kidney donors as controls and a total of 86 Hispanic kidney transplant patients, whose renal failure was attributed to hypertensive nephropathy after ruling out diabetes mellitus or other causes, were genotyped for four different single nucleotide polymorphisms of VEGF: -2578 C>A (rs699947), -1154 G>A (rs1570360), -460 C>T (rs833061), and +936 C>T (rs3025039). The homozygous mutant type (AA) of VEGF -1154 G>A (rs1570360) was found with significantly higher frequency in the hypertensive nephropathy patients than in controls. On the other hand, homozygous wild type (GG) was found less frequently in the hypertensive nephropathy patient group than in the control group. Linkage disequilibrium (LD) analyses revealed a high degree of LD among VEGF -2578 C>A (rs699947), VEGF -1154 G>A (rs1570360), and VEGF -460 C>T (rs833061). The haplotype analysis revealed that two haplotypes, CGTC and CATC (in the order of VEGF -2578 C>A (rs699947), -1154 G>A (1570360), -460 C>T (rs833061), and +936 C>T (3025039)), were significantly associated with hypertensive nephropathy in Hispanic patients. Hence, the -1154 G>A polymorphism (rs1570360) and two haplotypes (CGTC and CATC) of VEGF appear to be associated with hypertensive nephropathy in Hispanic patients who developed end-stage renal disease requiring kidney transplant.

Association between vascular endothelial growth factor and hypertension in children and adolescents type I diabetes mellitus

The aim of the study was to analyse the relationship between the serum level of vascular endothelial growth factor (VEGF) and the incidence of hypertension (HT) in children and adolescents with type I diabetes mellitus (T1DM). One hundred and five patients with T1DM were enrolled in the study. The control group consisted of 30 healthy controls. All the T1DM patients were subjected to biochemical analyses, ophthalmologic examination and 24-h blood pressure monitoring. Besides, all the patients and healthy controls had serum VEGF levels measured with the use of the ELISA methodology. The essence of our research is that patients with T1DM and HT and with microalbuminuria (MA) and diabetic retinopathy (DR) (MA/DR) are characterized by a significantly higher level of VEGF (340.23±93.22 pg ml(-1)) in blood serum in comparison with the group of T1DM patients without HT and MA/DR (183.6±96.6 pg ml(-1)) and with healthy controls (145.32±75.58 pg ml(-1)). In addition, the VEGF level was significantly higher in T1DM patients, who presented all three complications, that is HT, retinopathy and MA in comparison with T1DM patients without HT, but with MA/DR (P=0.036). On the other hand, no statistically significant differences (P=0.19) were noted in the level of VEGF in serum between T1DM patients without HT and MA/DR and the healthy control group. At a further stage of analysis, using the method of multiple regression, it was shown that systolic pressure, HbA1c and duration of disease are independent factors influencing the concentration of VEGF. Summarizing, the measurement of VEGF serum levels allows for the identification of groups of patients who have the highest risk of HT and, subsequently, progression of vascular complications.

Angiogenesis and biomarkers of cardiovascular risk in adults with metabolic syndrome

OBJECTIVES

Metabolic syndrome (MetSyn) is associated with an increased risk of atherosclerosis and fatal cardiovascular events. Angiogenesis is thought to contribute to this risk as it might be involved in the progression of atherosclerotic plaques. We investigated the levels of circulating biomarkers of angiogenesis and cardiovascular risk in adults with MetSyn and assessed their association with established metabolic risk factors.

DESIGN

The Genetic Park project is a highly inclusive cross-sectional survey (about 80% of residents) conducted in three isolated populations in Southern Italy. A total of 1000 men and women (age range: 18-98 years) were included in the analysis. Anthropometric and blood pressure measurements were recorded. Metabolic and cardiovascular biomarkers included glucose, triglycerides, total cholesterol, HDL, vascular endothelial growth factor, placental growth factor (PlGF), soluble fms-like tyrosine kinase-1, high-sensitivity C-reactive protein, high-sensitivity troponin T (hs-TnT) and N-terminal pro-brain natriuretic peptide (NT-proBNP).

RESULT

Subjects with MetSyn had higher levels of PlGF and NT-proBNP after adjustment for age, smoking and body mass index. Circulating levels of PlGF, hs-TnT and NT-proBNP were directly related to the number of criteria of MetSyn, and this association interacted with gender. There was a strong correlation between ageing and cardiovascular risk.

CONCLUSIONS

The increase in circulating levels of biomarkers of angiogenesis and cardiac function in subjects with MetSyn mirrors the pathophysiological changes occurring in the cardiovascular system. Over time, these changes might accelerate the formation and progression of atherosclerotic plaques and contribute significantly to cardiovascular morbidity and mortality risk.

Urinary albumin excretion is associated with pulmonary hypertension in sickle cell disease: potential role of soluble fms-like tyrosine kinase-1

BACKGROUND

Pulmonary hypertension (PHT) is reported to be associated with measures of renal function in patients with sickle cell disease (SCD). The purpose of this exploratory study was to determine the relationship between albuminuria and both clinical and laboratory variables in SCD.

DESIGN AND METHODS

This cross-sectional study was performed using a cohort of adult patients with SCD and control subjects without SCD. Spot urine for microalbumin/creatinine ratio, measures of hemolysis, inflammation and other laboratory studies were obtained. Pulmonary artery systolic pressure was determined by Doppler echocardiography, and the diagnosis of PHT was defined using age-, sex- and body mass index-adjusted reference ranges.

RESULTS

Seventy-three patients with SCD and 21 healthy, race-matched control subjects were evaluated. In patients with SCD, normoalbuminuria was observed in 34 patients (46.6%), microalbuminuria in 24 patients (32.9%) and macroalbuminuria in 15 patients (20.5%). There was a significant correlation between urine albumin excretion and age. In patients with HbSS and Sbeta(0) thalassemia, the levels of sFLT-1, soluble VCAM and NT pro-BNP were significantly higher in those with macroalbuminuria, compared to patients with microalbuminuria and normoalbuminura, but no significant differences were observed in the levels of laboratory measures of hemolysis. Urine albumin excretion was associated with PHT and a history of stroke.

CONCLUSIONS

Our study confirms the high prevalence of albuminuria in SCD. The association of urine albumin excretion with sFLT-1 suggests that this vascular endothelial growth factor receptor family member may contribute to the development of albuminuria in SCD. By inducing endothelial activation and endothelial dysfunction, sFLT-1 appears to be a link between glomerulopathy and PHT in SCD.