Use of human VEGF(165) gene for therapeutic angiogenesis in coronary patients: first results

Progress in Clinical Gene Therapy for Cardiac Disorders

Despite significant advances in novel treatments and approaches, cardiovascular disease remains the leading cause of death globally. Gene therapy is a promising option for many diseases, including cardiovascular diseases. In the last 30 years, gene therapy has slowly proceeded towards clinical translation and recently reached US Food and Drug Administration approval for several diseases such as Leber congenital amaurosis and spinal muscular atrophy, among others. Previous attempts at developing gene therapies for cardiovascular diseases have yielded promising results in preclinical studies and early-phase clinical trials. However, larger trials failed to demonstrate consistent benefits in patients with ischemic heart disease and heart failure. In this review, we summarize the history and current status of clinical cardiac gene therapy. Starting with angiogenic gene therapy, we also cover more recent gene therapy trials for heart failure and cardiomyopathies. New programs are actively vying to be the first to get Food and Drug Administration approval for a cardiac gene therapy product by taking advantage of novel techniques.

Gene therapy for refractory angina and cell therapy for heart failure: experience of a Brazilian research group

Cell therapy has shown impressive effects in experimental cardiomyopathy models. To a lesser extent, gene therapy has also been studied. In both cases, translation to clinical therapy has been disappointing. This paper is intended to describe the experience and achievements of a multicenter working group located in Porto Alegre, southern Brazil, in experimental and translational research projects for cell-based and gene therapy methods in the treatment of dilated and ischemic cardiomyopathies. The results of preclinical and clinical studies showed that bone marrow mononuclear stem cells indeed have an effect in improving myocardial perfusion and contractile function, but the overall results are poorly translated to the clinical level. Gene therapy studies with direct myocardial injections of naked VEGF 165 plasmid showed improvement in myocardial perfusion and function in animal models. A randomized clinical trial found that this method is safe and improved myocardial perfusion, but the benefits disappeared after 1 year. An animal experiment associating VEGF 165 with angiopoietin was undertaken in mini pigs to extend the durability of that therapy. In conclusion, our efforts to better understand the mechanisms and functions of gene and cell-based therapies in cardiology resulted in significant findings and propose a future look at cell-free therapeutic approaches.

Angiogenic growth factors in myocardial infarction: a critical appraisal

In the recent past, substantial advances have been made in the treatment of myocardial infarction (MI). Despite the impact of these positive developments, MI remains to be a leading cause of morbidity as well as mortality. An interesting hypothesis is that the development of new blood vessels (angiogenesis) or the remodeling of preexisting collaterals may form natural bypasses that could compensate for the occlusion of an epicardial coronary artery. A number of angiogenic factors are proven to be elicited during MI. Exogenous supplementation of these growth factors either in the form of recombinant protein or gene would enhance the collateral vessel formation and thereby improve the outcome after MI. The aim of this review is to describe the nature and potentials of different angiogenic factors, their expression, their efficacy in animal studies, and clinical trials pertaining to MI.

Effect of exogenous administration of vascular endothelial growth factor on hepatic microvessel density in rats with liver cirrhosis

AIM: To investigate the effect of portal vein administration of vascular endothelial growth factor on the density of hepatic microvessels in rats with liver cirrhosis.

METHODS: Twenty-five male Sprague-Dawley rats with portal hypertension were randomly divided into two groups: treatment group (n = 15) and model group (n = 10). The treatment group was given recombinant rat vascular endothelial growth factor 165 (30 ng/d) via the portal vein for 2 weeks. The model group underwent only sham operation. Ten normal rats were used as normal controls. After treatment, liver histopathology was examined by light microscopy and sinusoidal ultrastructure was observed by transmission electron microscopy. The density of hepatic microvessels was detected by immunostaining of von Willebrand factor (vWF).

RESULTS: Light microscopy examination showed that hepatic fibrosis improved in the treatment group compared with the model group. Electron microscopy analysis showed decreased number of fenestrations in sinusoidal endothelial cells, basement membrane formation, and irregular hepatic sinus endothelial cells. These pathological changes were more severe in the model group than in the treatment group. Microvessel density was higher in fibrotic stroma (2.04 ± 0.61 vs 1.26 ± 0.30, P < 0.01) but lower in liver parenchyma (0.74 ± 0.05 vs 1.32 ± 0.48, P < 0.01) in the treatment group than in the model group. However, microvessel density in both liver stroma and parenchyma was higher in the treatment and model groups than in the normal control group (1.26 ± 0.30, 2.04 ± 0.61 vs 0.70 ± 0.07; 1.32 ± 0.48, 0.74 ± 0.05 vs 0.28 ± 0.08, all P < 0.05).

CONCLUSION: Exogenous administration of vascular endothelial growth factor is capable of increasing the number of microvessels in fibrotic stroma but decreasing that in liver parenchyma.

Therapeutic myocardial angiogenesis

Armed with an improved understanding of the mediators of angiogenesis, physicians and scientists have made significant efforts at harnessing this naturally occurring process in order to treat patients with a variety of peripheral vascular and coronary ischemic syndromes. There is a growing population of patients with end-stage coronary artery disease (CAD) who are no longer candidates for mechanical revascularization, yet suffer from chronic myocardial ischemia who may benefit from regeneration of the depleted microvasculature.