Novel vascular endothelial growth factor D variants with increased biological activity.

Members of the vascular endothelial growth factor (VEGF) family play a pivotal role in angiogenesis and lymphangiogenesis. They are potential therapeutics to induce blood vessel formation in myocardium and skeletal muscle, when normal blood flow is compromised. Most members of the VEGF/platelet derived growth factor protein superfamily exist as covalently bound antiparallel dimers.

Therapeutic angiogenesis with placental growth factor improves exercise tolerance of ischaemic rabbit hindlimbs.

Aims: We investigated the effects of angiogenic gene therapy with adenoviral placental growth factor(131) (AdPlGF) on aerobic capacity and exercise tolerance in a rabbit hindlimb ischaemia model. We also assessed whether strong angiogenic changes such as capillary arterialization and formation of artery-venous shunts compromise oxygen transport to target tissues resulting in suboptimal therapeutic efficacy.

Methods And Results: Hindlimb ischaemia was surgically induced in New Zealand White rabbits (n = 20) that a day later received intramuscular (i.

15-lipoxygenase-1 prevents vascular endothelial growth factor A- and placental growth factor-induced angiogenic effects in rabbit skeletal muscles via reduction in growth factor mRNA levels, NO bioactivity, and downregulation of VEGF receptor 2 expression.

Human 15-lipoxygenase-1 (15-LO-1) is an oxidizing enzyme capable of producing reactive lipid hydroperoxides. 15-LO-1 and its products have been suggested to be involved in many pathological conditions, such as inflammation, atherogenesis, and carcinogenesis. We used adenovirus-mediated gene transfers to study the effects of 15-LO-1 on vascular endothelial growth factor (VEGF)-A165- and placental growth factor (PlGF)-induced angiogenesis in rabbit skeletal muscles.

Enhanced capillary formation stimulated by a chimeric vascular endothelial growth factor/vascular endothelial growth factor-C silk domain fusion protein.

Vascular endothelial growth factor (VEGF)-C and VEGF-D require proteolytic cleavage of the carboxy terminal silk-homology domain for activation. To study the functions of the VEGF-C propeptides, we engineered a chimeric growth factor protein, VEGF-CAC, composed of the amino- and carboxy-terminal propeptides of VEGF-C fused to the receptor-activating core domain of VEGF. Like VEGF-C, VEGF-CAC underwent proteolytic cleavage, and like VEGF, it bound to and activated VEGF receptor-1 and VEGF receptor-2, but not the VEGF-C receptor VEGF receptor-3.

Distinct architecture of lymphatic vessels induced by chimeric vascular endothelial growth factor-C/vascular endothelial growth factor heparin-binding domain fusion proteins.

Vascular endothelial growth factor (VEGF)-C and VEGF-D are composed of the receptor-binding VEGF homology domain and a carboxy-terminal silk homology domain that requires proteolytic cleavage for growth factor activation. Here, we explored whether the C-terminal heparin-binding domain of the VEGF(165) or VEGF(189) isoform also containing neuropilin-binding sequences could substitute for the silk homology domain of VEGF-C. Such VEGF-C/VEGF-heparin-binding domain chimeras were produced and shown to activate VEGF-C receptors, and, when expressed in tissues via adenovirus or adeno-associated virus vectors, stimulated lymphangiogenesis in vivo.

Blood flow remodels growing vasculature during vascular endothelial growth factor gene therapy and determines between capillary arterialization and sprouting angiogenesis.

Background: For clinically relevant proangiogenic therapy, it would be essential that the growth of the whole vascular tree is promoted. Vascular endothelial growth factor (VEGF) is well known to induce angiogenesis, but its capability to promote growth of larger vessels is controversial. We hypothesized that blood flow remodels vascular growth during VEGF gene therapy and may contribute to the growth of large vessels.

Growth factor-induced therapeutic angiogenesis and arteriogenesis in the heart--gene therapy.

Myocardial ischemia is one of the most promising targets of gene therapy. Although several growth factors and delivery approaches have yielded positive results in preclinical studies, first clinical studies have shown little or no real clinical benefit to the patients. It is likely that less than optimal gene therapy approaches have been used so far, and more thorough preclinical studies are needed in order to establish safe, efficient pro-angiogenic therapy.

Gene therapy for ischemic cardiovascular diseases: some lessons learned from the first clinical trials.

Stimulation of angiogenesis, arteriogenesis, and lymphangiogenesis (i.e., therapeutic vascular growth) is a new concept for the treatment of ischemic cardiovascular diseases.

Gene transfer into rabbit arteries with adeno-associated virus and adenovirus vectors.

Background: Gene transfer offers considerable potential for altering vessel wall physiology and intervention in vascular disease. Therefore, there is great interest in developing optimal strategies and vectors for efficient, targeted gene delivery into a vessel wall.

Methods: We studied adeno-associated viruses (AAV; 9 x 10(8) to 4 x 10(9) TU/ml) for their usefulness to transduce rabbit arteries in vivo in comparison with adenoviruses (Adv; 1 x 10(9) to 1 x 10(10) pfu/ml).

Adenoviral catheter-mediated intramyocardial gene transfer using the mature form of vascular endothelial growth factor-D induces transmural angiogenesis in porcine heart.

Background: It is unclear what is the most efficient vector and growth factor for induction of therapeutic vascular growth in the heart. Furthermore, the histological nature of angiogenesis and potential side effects caused by different vascular endothelial growth factors (VEGFs) in myocardium have not been documented.

Methods And Results: Adenoviruses (Ad) at 2 doses (2x10(11) and 2x10(12) viral particles) or naked plasmids (1 mg) encoding LacZ control, VEGF-A165, or the mature, soluble form of VEGF-D (VEGF-D(DeltaNDeltaC)) were injected intramyocardially with the NOGA catheter system into domestic pigs.

VEGF-D is the strongest angiogenic and lymphangiogenic effector among VEGFs delivered into skeletal muscle via adenoviruses.

Optimal angiogenic and lymphangiogenic gene therapy requires knowledge of the best growth factors for each purpose. We studied the therapeutic potential of human vascular endothelial growth factor (VEGF) family members VEGF-A, VEGF-B, VEGF-C, and VEGF-D as well as a VEGFR-3-specific mutant (VEGF-C156S) using adenoviral gene transfer in rabbit hindlimb skeletal muscle. The significance of proteolytic processing of VEGF-D was explored using adenoviruses encoding either full-length or mature (DeltaNDeltaC) VEGF-D.

Fibroblast growth factor 4 induces vascular permeability, angiogenesis and arteriogenesis in a rabbit hindlimb ischemia model.

Previous studies have shown that fibroblast growth factor (FGF)-1, FGF-2, and FGF-5 induce therapeutic angiogenesis. Here, we investigated the potential of FGF-4 for therapeutic neovascularization in comparison to vascular endothelial growth factor (VEGF), using adenoviral gene transfer in a novel rabbit hind limb ischemia model, with ischemia restricted to the calf. Magnetic resonance imaging and a modified Miles assay showed that both AdFGF-4 and AdVEGF given intramuscularly (i.

Gene therapy for restenosis: current status.

Atherosclerosis is a major cause of morbidity and mortality in Western world. Vascular occlusion caused by atherosclerosis usually requires invasive treatment, such as surgical bypass or angioplasty. However, bypass graft failure and restenosis limit the usefulness of these procedures, with 20% of patients needing a new revascularisation procedure within 6 months of angioplasty.

Expression of vascular endothelial growth factor and vascular endothelial growth factor receptor-2 (KDR/Flk-1) in ischemic skeletal muscle and its regeneration.

Vascular endothelial growth factor (VEGF) is a hypoxia-inducible endothelial cell mitogen and survival factor. Its receptor VEGFR-2 (KDR/Flk-1) mediates these effects. We studied the expression of VEGF and VEGFR-2 in ischemic human and rabbit skeletal muscle by immunohistochemistry and in situ hybridization.