Role of circulating vascular endothelial growth factor and hepatocyte growth factor in patients with coronary artery disease

Intramyocardial delivery of VEGF165 via a novel biodegradable hydrogel induces angiogenesis and improves cardiac function after rat myocardial infarction

Vascular endothelial growth factor (VEGF), an independent mitogen, has been reported to induce angiogenesis and thus attenuates the damage induced by myocardial infarction (MI). VEGF165 is the most abundant and predominant isoform of VEGF. This study investigates whether this effect could be strengthened by local intramyocardial injection of VEGF165 along with a novel biodegradable Dex-PCL-HEMA/PNIPAAm hydrogel and ascertains its possible mechanism of action. Rat models of myocardial infarction were induced by coronary artery ligation. Phosphate-buffered saline (PBS group), Dex-PCL-HEMA/PNIPAAm hydrogel (Gel group), phosphate-buffered saline containing VEGF165 (VP group), and hydrogel containing VEGF165 (VPG group) were injected into a peri-infarcted area of cardiac tissue immediately after myocardial infarction, respectively. The sham group was thoracic but without myocardial infarction. The injection of VEGF165 along with a hydrogel induced angiogenesis, reduced collagen content and MI area, inhibited cell apoptosis, increased the level of VEGF165 protein and the expression of flk-1 and flt-1, and improved cardiac function compared with the injection of either alone after MI in rats. The results suggest that injection of VEGF165 along with a hydrogel acquires more cardioprotective effects than either alone in rat with MI by sustained release of VEGF165, then may enhance the feedback between VEGF and its receptors flk-1 and flt-1.

Stable phase post-MI patients have elevated VEGF levels correlated with inflammation markers, but not with atherosclerotic burden

BACKGROUND

The role of vascular endothelial growth factor (VEGF) in patients in the stable phase after myocardial infarction (MI) has not yet been explored. Therefore, we compared the values of VEGF in post-MI patients with those obtained in healthy controls. Furthermore, we investigated whether the values of VEGF correlate to either inflammation markers or the atherosclerotic burden.

METHODS

41 male patients (on average 44 years old) in the stable phase after MI (on average 20.5 months after MI) were recruited, while 25 healthy age-matched males served as controls. Plasma levels of VEGF and several markers of inflammation were measured by standard procedures. The atherosclerotic burden was determined by the angiographic severity of coronary atherosclerosis, endothelial dysfunction (measured by ultrasound measurement of the flow mediated dilation of the brachial artery), the intima-media thickness of the common carotid artery and the ankle-brachial pressure index.

RESULTS

VEGF values were significantly elevated in post-MI patients compared to the controls (53.8 ± 42.7 pg/ml vs. 36.3 ± 8.9 pg/ml, p = 0.014). The elevated VEGF values significantly correlated to the (increased) values of the inflammatory molecules interleukin 6 and 8 (r = 0.37, p = 0.017; and r = 0.45, p = 0.003; respectively). In contrast, no correlation was found between VEGF and the parameters of the atherosclerotic burden, although FMD and IMT were significantly impaired in patients.

CONCLUSIONS

We found that plasma levels of VEGF are increased in the stable phase after MI and correlate with inflammation cytokines, but not with the atherosclerotic burden. Thus, this suggests that increased levels of VEGF are a part of ongoing inflammatory activity. Since VEGF in these patients stimulates neovascularization of inflamed plaques and induces their destabilization, the VEGF level can have an important negative prognostic value. Clearly, further studies are needed to clarify the role of VEGF as a prognostic marker.

In vitro endothelial cell proliferation assay reveals distinct levels of proangiogenic cytokines characterizing sera of healthy subjects and of patients with heart failure

Although myocardial angiogenesis is thought to play an important role in heart failure (HF), the involvement of circulating proinflammatory and proangiogenic cytokines in the pathogenesis and/or prognosis of HF has not been deeply investigated. By using a highly standardized proliferation assay with human endothelial cells, we first demonstrated that sera from older (mean age 52 ± 7.6 years; n = 46) healthy donors promoted endothelial cell proliferation to a significantly higher extent compared to sera obtained from younger healthy donors (mean age 29 ± 8.6 years; n = 20). The promotion of endothelial cell proliferation was accompanied by high serum levels of several proangiogenic cytokines. When we assessed endothelial cell proliferation in response to HF patients' sera, we observed that a subset of sera (n = 11) promoted cell proliferation to a significantly lesser extent compared to the majority of sera (n = 18). Also, in this case, the difference between the patient groups in the ability to induce endothelial cell proliferation correlated to significant (P < 0.05) differences in serum proangiogenic cytokine levels. Unexpectedly, HF patients associated to the highest endothelial proliferation index showed the worst prognosis as evaluated in terms of subsequent cardiovascular events in the follow-up, suggesting that high levels of circulating proangiogenic cytokines might be related to a worse prognosis.

A novel method of augmenting gene expression and angiogenesis in the normal and ischemic canine myocardium

This study presents a novel method that direct intramyocardial injection of low-dose plasmid DNA and microbubbles combined with insonation could further augment gene expression in normal and ischemic canine myocardium. Plasmids encoding enhanced green fluorescent protein (pEGFP) and hepatocyte growth factor (pHGF) (500 μg) were individually mixed with 0.5 ml of microbubble solution (MB) and injected into the normal or acute ischemic canine myocardium. The dogs in the plasmid + MB/US group underwent insonation (US). Other dogs were randomly divided into three treatment groups: plasmid and insonation, plasmid and MB injection, and plasmid injection only. The EGFP and HGF mRNA expressions were assessed in the myocardium at the injection site and at sites 0.5 and 1 cm remote from the injection site. Compared to plasmid transfer alone, a mean 13.4-fold enhancement of gene expression was achieved in the EGFP + MB/US group at 48 h (p < 0.01). HGF mRNA expression in ischemic zones was markedly elevated after 28 days, with a mean 9.0-fold enhancement in the HGF + MB/US group (p < 0.01). EGFP protein expression was detected in the normal myocardium at 1 cm remote from the injection site in the EGFP + MB/US group. Similarly, HGF protein expression was detected in the ischemic myocardium at 0.5 cm remote from the injection site in the HGF + MB/US group. These findings indicate that the radius of gene expression was partly extended in the two plasmid + MB/US groups. The capillary density increased from 20.9 ± 5.3/mm(2) in control myocardial infarction dogs without treatment to 126.7 ± 38.2/mm(2) in the HGF + MB/US group (p < 0.01). Taken together, the present data demonstrate that direct intramyocardial injection of an angiogenic gene and microbubbles combined with insonation can augment gene expression and angiogenesis. Consequently, this strategy may be a useful tool for gene therapy of ischemic heart disease.

Vascular endothelial growth factor, its soluble receptor, and hepatocyte growth factor: clinical and genetic correlates and association with vascular function

AIMS

Growth factors play an important role in regulating vascular function. Data are limited regarding clinical and genetic correlates of endothelial growth factors and their associations with vascular function.

METHODS AND RESULTS

We evaluated clinical and genetic correlates of circulating vascular endothelial growth factor A (VEGF), its soluble receptor sFlt-1, and hepatocyte growth factor (HGF) in 3754 Framingham Study participants. We also related the growth factors to measures of brachial artery function. Serum VEGF and HGF were higher and sFLt-1 was lower in women and smokers. VEGF and HGF were associated positively with body mass index; both displayed strong positive associations with the metabolic syndrome (P < 0.001) and its components. The heritabilities of VEGF, sFlt-1, and HGF were 78, 13, and 38%, respectively. VEGF and HGF were related positively to baseline brachial diameter (P < 0.01) and to baseline mean flow velocity (P < 0.001) in age- and sex-adjusted models, but the multivariable models failed to reach significance. None of the growth factors were related to flow-mediated dilation.

CONCLUSION

In our community-based sample, circulating VEGF and HGF demonstrated high heritabilities and a sexual dimorphism. Increased angiogenesis and greater endothelial cell turnover may underlie associations of these growth factors with risk factors including smoking.

Vascular endothelial growth factors in cardiovascular medicine

The discovery of vascular endothelial growth factors (VEGFs) and their receptors has considerably improved the understanding of the development and function of endothelial cells. Each member of the VEGF family appears to have a specific function: VEGF-A induces angiogenesis (i.e. growth of new blood vessels from preexisting ones), placental growth factor mediates both angiogenesis and arteriogenesis (i.e. the formation of collateral arteries from preexisting arterioles), VEGF-C and VEGF-D act mainly as lymphangiogenic factors. The study of the biology of these endothelial growth factors has allowed a major progress in the comprehension of the genesis of the vascular system and its abnormalities observed in various pathologic conditions (atherosclerosis and coronary artery disease). The role of VEGF in the atherogenic process is still unclear, but actual evidence suggests both detrimental (development of a neoangiogenetic process within the atherosclerotic plaque) and beneficial (promotion of collateral vessel formation) effects. VEGF and other angiogenic growth factors (fibroblast growth factor), although initially promising in experimental studies and in initial phase I/II clinical trials in patients with ischemic heart disease or peripheral arterial occlusive disease, have subsequently failed to show significant therapeutic improvements in controlled clinical studies. Challenges still remain about the type or the combination of angiogenic factors to be administered, the form (protein vs. gene), the route, and the duration of administration.

MR assessment of myocardial perfusion, viability, and function after intramyocardial transfer of VM202, a new plasmid human hepatocyte growth factor in ischemic swine myocardium

PURPOSE

VM202, a newly constructed plasmid human hepatocyte growth factor, was transferred intramyocardially after infarction for the purpose of evaluating this strategy as a therapeutic approach for protection from left ventricular (LV) remodeling.

MATERIALS AND METHODS

The institutional animal care and use committee approved this study. Pigs underwent coronary artery occlusion and reperfusion and served as either control (n = 8) or VM202-treated (n = 8) animals. VM202 was transferred intramyocardially into four infarcted and four periinfarcted sites. Cardiac magnetic resonance (MR) imaging (cine, perfusion, delayed enhancement) was performed in acute (3 days) and chronic (50 days +/- 3 [standard error of the mean]) infarction. Histopathologic findings were used to characterize and quantify neovascularization. The t test was utilized to compare treated and control groups and to assess changes over time.

RESULTS

In acute infarction, MR imaging estimates of function, perfusion, and viability showed no difference between the groups. In chronic infarction, however, VM202 increased maximum signal intensity and upslope at first-pass perfusion imaging and reduced infarct size at perfusion and delayed-enhancement imaging. These changes were associated with a decrease in end-diastolic (2.15 mL/kg +/- 0.12 to 1.73 mL/kg +/- 0.10, P < .01) and end-systolic (1.33 mL/kg +/- 0.07 to 0.92 mL/kg +/- 0.08, P < .001) volumes and an increase in ejection fraction (38.2% +/- 1.3 to 47.0% +/- 1.8, P < .001). In contrast, LV function deteriorated further in control animals. Compared with control animals, VM202-treated animals revealed peninsulas and/or islands of viable myocardium in infarcted and periinfarcted regions and greater number of capillaries (218 per square millimeter +/- 19 vs 119 per square millimeter +/- 17, P < .05) and arterioles (21 per square millimeter +/- 4 vs 3 per square millimeter +/- 1, P < .001).

CONCLUSION

Intramyocardial transfer of VM202 improved myocardial perfusion, viability, and LV function.

Overexpression of TGFbeta1 by adeno-associated virus type-2 vector protects myocardium from ischemia-reperfusion injury

Transforming growth factor beta(1) (TGFbeta(1)) has been purported to protect tissues from ischemia-reperfusion (I-R) injury. This study was designed to examine if overexpression of TGFbeta(1) using adeno-associated virus type 2 (AAV) protects cardiomyocytes from reoxygenation injury. TGFbeta(1) was overexpressed in cultured HL-1 mouse cardiomyocytes by transfection with AAV/TGFbeta(1)(Latent) or with AAV/TGFbeta(1)(ACT) (active TGFbeta(1)). TGFbeta(1) upregulation reduced cardiomyocyte apoptosis and necrosis induced by 24 h of hypoxia followed by 3 h of reoxygenation concomitant with reduction in reactive oxygen species release, activation of nicotinamide adenine dinucleotide phosphate (NADPH) oxidase and NF-kappaB expression. Transfection with AAV/TGFbeta(1)(ACT) was superior to that with AAV/TGFbeta(1)(Latent). To determine if AAV/TGFbeta(1)(ACT) upregulation in vivo would induce cardioprotection from I-R injury, rat hearts were injected with AAV/TGFbeta(1)(ACT) or phosphate-buffered saline (PBS). Six weeks later, TGFbeta(1)(ACT) was upregulated throughout the myocardium. Following I-R, AAV/TGFbeta(1)(ACT)-overexpressing rats had much smaller infarct size (P<0.01 vs PBS group), which was also related to reduced activation of NADPH oxidase and NF-kappaB, and lower levels of malondialdehyde in I-R tissues. These data demonstrate that overexpression of TGFbeta(1) by AAV can protect cardiac tissues from reperfusion injury, possibly via antioxidant mechanism. These findings suggest potential of TGFbeta(1)(ACT) gene therapy for cardioprotection from I-R injury.

Circulating angiogenic cytokines and stem cells in patients with severe chronic ischemic heart disease — Indicators of myocardial ischemic burden?

BACKGROUND

Angiogenic growth factors and stem cell therapies have demonstrated varying results in patients with chronic coronary artery disease. A reason could be that these mechanisms are already up-regulated due to reduced blood supply to the myocardium. The objective of this study was to examine if plasma concentrations of circulating stem cells and angiogenic cytokines in patients with severe stable chronic coronary artery disease were correlated to the clinical severity of the disease.

METHODS

Fifty-four patients with severe coronary artery disease and reversible ischemia at stress myocardial perfusion scintigraphy were prospectively included. The severity of the disease was quantified by an exercise tolerance test, Canadian Cardiovascular Society angina classification, and Seattle Angina Pectoris Questionnaire. Fifteen persons without coronary artery disease served as control subjects.

RESULTS

Plasma concentration of VEGF-A, FGF-2, SDF-1, and circulating CD34+ and CD34-/CD45- cells were similar in the two groups, but early stem cell markers (CD105, CD73, CD166) and endothelial markers (CD31, CD144, VEGFR2) were significantly different between patients and control subjects (p<0.005-0.001). Diabetic patients had higher concentration of SDF-1 (2528 vs. 2150 pg/ml, p=0.004). We found significant correlations between both VEGF-A, FGF-2, and CD34+ to disease severity, including degree of reversible ischemia, angina stability score, and exertional dyspnoea.

CONCLUSIONS

Plasma concentrations of circulating stem cells and angiogenic cytokines have large inter-individual variations, which probably exclude them from being useful as indicators of myocardial ischemic burden.

Effect of hepatocyte growth factor (HGF) on the level of Survivin & XIAP expression in several human cancer cell lines, after treating with DNA damaging agent

Hepatocyte growth factor (HGF) has opposite biological activities in regulating apoptosis, also underlying molecular mechanisms are not clearly defined. We investigated HGF ability to inhibit cell death, which was induced by Doxorubicin, a DNA damaging agent. Also Survivin and XIAP mRNA levels were compared in HGF treated and non-treated cells. Cell proliferation and death were assessed using MTT assay and dye exclusion tests. Quantitative real-time PCR was used to evaluate Survivin and XIAP expression levels after treatment with HGF. ELISA was performed to quantify HGF secretion in the selected cancer cell lines media. HGF appeared to have inhibitory effect on Doxorubicin induced cell death in all of the studied cell lines. It had minimal effect on XAIP and Survivin expression levels in MRC-5, MOLT-4 and AGS cell lines; except for XIAP expression level in AGS cell line, which was increased substantially after treatment. Surprisingly, in KG-1 cell line, XIAP and Survivin expression levels were significantly reduced after HGF treatment. Although several members of IAP gene family are reported to play role in HGF mediated cytoprotective pathway, we showed that XIAP and Survivin do not seem to be involved.

Investigation of an albumin-enriched fraction of human serum and its albuminome

The removal of albumin and other high abundance proteins is a routine first step in the analysis of serum and plasma proteomes. However, as albumin can bind proteins and peptides, there is a universal concern as to how the serum proteome is changed by the removal of albumin. To address this concern, the current study was designed to identify proteins and peptides removed from the serum during albumin depletion; to determine which of these are bound to albumin (rather than copurified) and whether the bound proteins are intact proteins or peptide fragments. Sequential, independent analyses including both anti-albumin antibody (anti-HSA) affinity chromatography and SEC were used to isolate albumin-bound proteins. RP-HPLC and 1-D SDS-PAGE were then used to further separate the proteins prior to identification by MS/MS. Finally, whole protein molecular weight (MW) MS measurements coupled with protein coverage obtained by MS were combined to assess whether the bound proteins were intact or peptide fragments. Combining the results from multiple approaches, 35 proteins, of which 24 are intact, were found to be associated with albumin, and they include both known high and low abundance proteins.

Coordinate release of angiogenic growth factors after acute myocardial infarction: evidence of a two-wave production

BACKGROUND

Previous studies have shown that angiopoietic growth factors, including vascular endothelial growth factor (VEGF), angiopoietin-2 (Ang-2), hepatocyte growth factor (HGF) and transforming growth factor (TGF)-beta1 are released after acute myocardial infarction (AMI). It was suggested that the release of these factors, triggered by ischemia, may be related to a reparative neoangiogenetic process.

METHODS

Plasma VEGF, Ang-2, HGF and TGF-beta levels were measured on admission (baseline) and at various times during the acute (0-48 h) and the subacute (48-240 h) phase in 44 patients with AMI.

RESULTS

In the present study, we have explored in detail the kinetics of release of these growth factors after AMI with the precise aim of evaluating the existence of a double wave of release of these factors: (i) a first wave in the acute and (ii) a second one in the subacute period. The results of these analyses provided evidence for an early (peak at 24-28 h) and late (peak at approximately 170 h) increase of VEGF, Ang-2 and TGF-beta.

CONCLUSIONS

According to these data, we suggest that two waves of release of angiogenic factors occur after AMI. The early release makes part of an acute phase response, whereas the late release may underlie the induction of angiogenetic mechanisms involved in tissue reparation.

Effect of heparin on blood vascular endothelial growth factor levels in patients with ST-elevation acute myocardial infarction undergoing primary percutaneous coronary intervention

It has been demonstrated that high blood vascular endothelial growth factor (VEGF) levels in patients with myocardial infarction decrease rapidly after reperfusion, possibly in response to heparin administration. We measured serum VEGF concentration before and after heparin infusion in 105 patients with ST-elevation acute myocardial infarction (STEMI) who underwent primary percutaneous coronary intervention (PCI). Serum VEGF concentration in patients with STEMI was significantly higher than in healthy controls. After PCI, the concentration of VEGF decreased by approximately 70%, with the greatest decrease seen in patients with the highest initial VEGF levels. To determine whether heparin could decrease VEGF concentration by sequestering VEGF in the endothelium, a fixed dose of recombinant VEGF was incubated for 40 minutes with EA.hy926 endothelial cells in vitro. Recovery of VEGF from medium after culture was decreased by up to 15% with increasing doses of heparin. Concentration of VEGF did not change in the absence of heparin and/or endothelial cells. In conclusion, these results suggest that a rapid decrease in blood VEGF after PCI may be related to the administration of heparin, which binds simultaneously to VEGF and endothelial cells.

Induction of angiogenesis and inhibition of apoptosis by hepatocyte growth factor effectively treats postischemic heart failure

BACKGROUND

Heart failure following myocardial infarction (MI) is a significant cause of morbidity and mortality and remains a difficult therapeutic challenge. Hepatocyte growth factor (HGF) is a potent angiogenic and anti-apoptotic protein whose receptor is upregulated following MI. This study was designed to investigate the ability of HGF to prevent heart failure in a rat model of experimental MI.

METHODS

The rats underwent direct intramyocardial injection with replication-deficient adenovirus encoding HGF (n = 7) or null virus as control (n = 7) 3 weeks following ligation of the left anterior descending coronary artery. Analysis of the following was performed 3 weeks after injection: cardiac function by pressure-volume conductance catheter measurements; LV wall thickness; angiogenesis by Von Willebrand's factor staining; and apoptosis by the TUNEL assay. The expression levels of HGF and the anti-apoptotic factor Bcl-2 were analyzed by Western blot.

RESULTS

Adeno-HGF-treated animals had greater preservation of maximum LV pressure (HGF 77 +/- 3 vs. control 64 +/- 5 mmHg, p < 0.05), maximum dP/dt (3024 +/- 266 vs. 1907 +/- 360 mmHg/sec, p < 0.05), maximum dV/dt (133 +/- 20 vs. 84 +/- 6 muL/sec, p < 0.05), and LV border zone wall thickness (1.98 +/- 0.06 vs. 1.53 +/- 0.07 mm, p < 0.005). Angiogenesis was enhanced (151 +/- 10.0 vs. 90 +/- 4.5 endothelial cells/hpf, p < 0.005) and apoptosis was reduced (3.9 +/- 0.3 vs. 8.2 +/- 0.5%, p < 0.005). Increased expression of HGF and Bcl-2 protein was observed in the Adeno-HGF-treated group.

CONCLUSIONS

Overexpression of HGF 3 weeks post-MI resulted in enhanced angiogenesis, reduced apoptosis, greater preservation of ventricular geometry, and preservation of cardiac contractile function. This technique may be useful to treat or prevent postinfarction heart failure.

The use of transformed Escherichia coli for experimental angiogenesis induced by regulated in situ production of vascular endothelial growth factor--an alternative gene therapy

BACKGROUND

Defects in angiogenesis (blood vessel formation) are responsible for two most important causes of death in developed countries (ischemic heart disease and cancer). Vascular endothelial growth factor (VEGF) plays a pivotal role in physiological and pathological regulation of angiogenesis. In the last years several studies have indicated the possibilities of VEGF in the therapy of ischemic heart disease. However, especially VEGF gene therapy (naked DNA, plasmids and adenovirus mediated) is associated with adverse side effects regarding the expression regulation.

AIM

To prepare bacterial strains producing VEGF using plasmids containing the VEGF cDNA for the use in experimental angiogenesis.

METHODS AND RESULTS

Escherichia coli strain BL21(DE3) was transformed with Bluescript vector containing the inserts with cDNA sequences coding VEGF-A isoforms (VEGF121, VEGF164, VEGF189). Selection of recombinants was achieved by cultivating E. coli cells on ampicillin-added medium. The expression of target genes in the T7 expression system was induced by isopropyl-beta-D-thiogalactoside (IPTG). Polyacrylamide gel electrophoresis of the cell lysates showed the presence of polypeptides of molecular weight corresponding with known values of VEGF isoforms. Blood vessel formation induced by bacterial VEGF production was proved in vivo in mice seven days after intraperitoneal injection of transformed bacteria by light microscopy. CONCLUSION AND HYPOTHESIS: In summary, E. coli strain expressing VEGF was prepared and its biological effect confirmed. Bacteria, which produce angiogenic factors, provide a new modality for experimental angiogenesis and may be also suitable for clinical use. The in situ production of therapeutic proteins using optimalized prokaryotic expression systems can represent a useful tool for treatment based on molecular biomedicine. The main advantage of the described approach lies in the enhanced regulation control--bacterial expression can be regulated positively (induction by exogenous low molecular weight agents) and negatively (application of antibiotics). The hypothesis of alternative gene therapy should be proved in further studies.

Vascular endothelial growth factor - basic science and its clinical implications

Vascular endothelial growth factor (VEGF) is the most important signaling molecule involved in the regulation of the formation of new vessels. Results of recent studies have provided new insights into the molecular mechanisms of the VEGF signaling pathways. VEGF local or systemic application represents a new approach in the therapy of ischemic diseases, especially of the coronary artery disease. Inhibition of the VEGF action on various levels is, on the other hand, assumed to be a promising therapeutic concept against cancer. Moreover, VEGF has been recently shown to be associated with some other physiological and pathophysiological processes. In this article we summarize the latest results of VEGF related studies and present the concluding theoretical resource for further research on the role of VEGF in understanding of pathophysiology of diseases and in therapeutic interventions in clinical biomedicine.

Peripheral monocytes from diabetic patients with coronary artery disease display increased bFGF and VEGF mRNA expression

BACKGROUND: Macrophages can produce vascular endothelial growth factor (VEGF) in response to hypoxia, transforming growth factor beta1 (TGF-beta1), angiotensin II, basic fibroblast growth factor (bFGF), and interleukin-1. These factors have been found in the serum of coronary artery disease (CAD) patients as well as in atherosclerotic lesions. The aim of the present study was to test the hypothesis that the expression of VEGF, TGF-beta1 and bFGF in peripheral monocytes and lymphocytes is related to CAD. METHODS: Human Mononuclear cells and lymphocytes from peripheral blood were isolated from 53 donors undergoing angiography. Seventeen were found to be healthy and 36 were diagnosed with CAD. The respective mRNAs were extracted and quantified. RESULTS: The statistical analysis revealed a significant increase of the basal level expression for macrophage VEGF and bFGF in the CAD SA (stable angina) patient group compared to the noCAD (control) (p = 0.041 and p = 0.022 respectively) and CAD UA (unstable angina) (p = 0.024 and p = 0.005 respectively) groups, which was highly dependent on the diabetic status of the population. Furthermore, we demonstrated with an in vitro cell culture model that the levels of VEGF and bFGF in monocytes of healthy donors are not affected by short term exposure to increased glucose levels (usually observed in the diabetic patients) and/or statin. CONCLUSION: Our findings display a statistically significant association of the increased VEGF and bFGF levels in peripheral monocytes, with stable angina and diabetes in coronary artery disease. The results give new insight to CAD and the impaired collateral vessel formation in diabetics.

Gene transfer of hepatocyte growth factor attenuates postinfarction heart failure

BACKGROUND

Despite advances in surgical and percutaneous coronary revascularization, ongoing ischemia that is not amenable to standard revascularization techniques is a major cause of morbidity and mortality. Hepatocyte Growth Factor (HGF) has potent angiogenic and anti-apoptotic activities, and this study evaluated the functional and biochemical effects of HGF gene transfer in a rat model of postinfarction heart failure.

METHODS AND RESULTS

Lewis rats underwent ligation of the left anterior descending coronary artery with direct intramyocardial injection of replication-deficient recombinant adenovirus encoding HGF (n=10) or empty null virus as control (n=9), and animals were analyzed after six weeks. Pressure-volume conductance catheter measurements demonstrated significantly preserved contractile function in the HGF group compared with Null control animals as measured by maximum developed LV pressure (79+/-5 versus 56+/-4 mm Hg, P<0.001) and maximum dP/dt (2890+/-326 versus 1622+/-159 mm Hg/sec, P<0.01). Significant preservation of LV geometry was associated with HGF treatment (LV Diameter HGF 13.1+/-0.54 versus Null 14.4+/-0.15 mm P<0.01; LV wall thickness 1.73+/-0.10 versus 1.28+/-0.07 mm P<0.01). Angiogenesis was significantly enhanced in HGF treated animals as measured by both Von Willebrand's Factor immunohistochemical staining and a microsphere assay. TUNEL analysis revealed a significant reduction in apoptosis in the HGF group (3.42+/-0.83% versus 8.36+/-1.16%, P<0.01), which correlated with increased Bcl-2 and Bcl-xL expression in the HGF animals.

CONCLUSIONS

Hepatocyte Growth Factor gene transfer following a large myocardial infarction results in significantly preserved myocardial function and geometry, and is associated with significant angiogenesis and a reduction in apoptosis. This therapy may be useful as an adjunct or alternative to standard revascularization techniques in patients with ischemic heart failure.

Early treatment with hepatocyte growth factor improves cardiac function in experimental heart failure induced by myocardial infarction

Plasma levels of hepatocyte growth factor (HGF) are increased within hours of cardiac ischemia/reperfusion in rats, and HGF has been shown to be cardioprotective toward acute ischemic injury. Myocardial levels of HGF mRNA and protein are increased for several days after myocardial infarction (MI), however, indicating a possible additional protective effect of HGF toward the progression of MI to heart failure. The purpose of this study was to determine whether HGF administration during the time course of endogenous cardiac HGF induction would lead to long-term improvement in cardiac function in rats with MI. MI was induced by 2-h occlusion of the left coronary artery, followed by reperfusion. HGF was given by intravenous infusion at 0.45 mg/kg/day for 6 days beginning on the day after surgery. Cardiac function and hemodynamic parameters were measured by using indwelling catheters and perivascular flow probes in conscious animals 8 weeks post-MI. Myocardial infarcts were approximately 30% of the left ventricle, and there was no difference in infarct size between the vehicle-treated and HGF-treated groups. Compared with untreated sham-operated rats, vehicle-treated MI animals had significantly lower cardiac index and stroke volume index and higher systemic vascular resistance, indicating heart failure developed. Treatment with HGF caused a significant increase in cardiac index and stroke volume index and a reduction in systemic vascular resistance in rats with MI, restoring these parameters close to those observed in sham-operated control animals. These results provide direct evidence that HGF may be of benefit to cardiovascular function in ischemic cardiomyopathy.