Endothelial Growth Factor Gene Therapy Research Articles

Gene therapy by virus-like self-spooling toroidal DNA condensates for revascularization of hindlimb ischemia

Peripheral arterial diseases (PAD) have been reported to be the leading cause for limb amputations, and the current therapeutic strategies including antiplatelet medication or intervene surgery are reported to not clinically benefit the patients with high-grade PAD. To this respect, revascularization based on angiogenetic vascular endothelial growth factor (VEGF) gene therapy was attempted for the potential treatment of critical PAD. Aiming for transcellular delivery of VEGF-encoding plasmid DNA (pDNA), we proposed to elaborate intriguing virus-like DNA condensates, wherein the supercoiled rigid micrometer-scaled plasmid DNA (pDNA) could be regulated in an orderly fashion into well-defined nano-toroids by following a self-spooling process with the aid of cationic block copolymer poly(ethylene glycol)-polylysine at an extraordinary ionic strength (NaCl: 600 mM). Moreover, reversible disulfide crosslinking was proposed between the polylysine segments with the aim of stabilizing these intriguing toroidal condensates. Pertaining to the critical hindlimb ischemia, our proposed toroidal VEGF-encoding pDNA condensates demonstrated high levels of VEGF expression at the dosage sites, which consequently contributed to the neo-vasculature (the particularly abundant formation of micro-vessels in the injected hindlimb), preventing the hindlimb ischemia from causing necrosis at the extremities. Moreover, excellent safety profiles have been demonstrated by our proposed toroidal condensates, as opposed to the apparent immunogenicity of the naked pDNA. Hence, our proposed virus-like DNA condensates herald potentials as gene therapy platform in persistent expressions of the therapeutic proteins, and might consequently be highlighted in the management of a variety of intractable diseases.

Neonatal outcomes following early fetal growth restriction: a subgroup analysis of the EVERREST study

ObjectiveTo quantify the risks of mortality, morbidity and postnatal characteristics associated with extreme preterm fetal growth restriction (EP-FGR).DesignThe EVERREST (Does vascular endothelial growth factor gene therapy safely improve outcome in...

H2O2-responsive VEGF/NGF gene co-delivery nano-system achieves stable vascularization in ischemic hindlimbs

Peripheral vascular disease (PVD) is a common clinical manifestation of atherosclerosis. Vascular endothelial growth factor (VEGF) gene therapy is a promising approach for PVD treatment. However, due to single-gene therapy limitations and high H2O2 pathological microenvironment, VEGF gene therapy are not as expectations and its clinical application are limited. Synergistic effects of Nerve factors and vascular factors in angiogenesis have attracted attention in recent years. In this study, VEGF and nerve growth factor (NGF) genes co-delivery nanoparticles (VEGF/NGF-NPs) were prepared by using H2O2 responsive 6s-PLGA-Po-PEG as a carrier. 6s-PLGA-Po-PEG could react with H2O2 specifically due to the internal peroxalate bond. Angiogenic effects of VEGF/NGF-NPs has been evaluated in cells and hindlimb ischemia mice model. Results showed that VEGF/NGF-NPs promoted VEGF and NGF co-expression simultaneously, eliminated excessive H2O2, strengthened reactions between SH-SY5Ys and HUVECs, and finally enhanced migration, tube formation, proliferation and H2O2 damage resistance of HUVECs. VEGF/NGF-NPs also recovered blood perfusion, promoted the expression of VEGF, NGF, eNOS and NO, and enhanced vascular coverage of pericytes. Treatment effects of VEGF/NGF-NPs may related to VEGF/eNOS/NO pathway. Altogether, VEGF/NGF-NPs eliminated excessive H2O2 while achieving gene co-delivery, and promoted stable angiogenesis. It’s a promising way for PVD treatment by using VEGF/NGF-NPs.Graphical

Pharmacological interventions for the prevention of fetal growth restriction: protocol for a systematic review and network meta-analysis

IntroductionFetal growth restriction (FGR) includes different conditions in which a fetus fails to reach the own full growth, and accounts for 28%–45% of non-anomalous stillbirths. The management of FGR is...

Achieving orphan designation for placental insufficiency: annual incidence estimations in Europe.

To determine whether a novel therapy for placental insufficiency could achieve orphan drug status by estimating the annual incidence of placental insufficiency, defined as an estimated fetal weight below the 10th centile in the presence of abnormal umbilical artery Doppler velocimetry, per 10000 European Union (EU) population as part of an application for European Medicines Agency (EMA) orphan designation. Incidence estimation based on literature review and published national and EU statistics. European Union. Data were drawn from published literature, including national and international guidelines, international consensus statements, cohort studies and randomised controlled trials, and published national and EU statistics, including birth rates and stillbirth rates. Rare disease databases were also searched. The proportion of affected pregnancies was estimated as 3.17% (95% CI 2.93-3.43%), using a weighted average of the results from two cohort studies. Using birth rates from 2012 and adjusting for a pregnancy loss rate of 1/100 gave an estimated annual incidence of 3.33 per 10000 EU population (95% CI 3.07-3.60 per 10000 EU population). This fell below the EMA threshold of 5 per 10000 EU population. Maternal vascular endothelial growth factor gene therapy for placental insufficiency was granted EMA orphan status in 2015 after we demonstrated that it is a rare, life-threatening or chronically debilitating and currently untreatable disease. Developers of other potential obstetric therapies should consider applying for orphan designation, which provides financial and regulatory benefits. Placental insufficiency meets the European Medicines Agency requirements for orphan disease designation.

Vascular endothelial growth factor gene transfer therapy for coronary artery disease: A systematic review and meta-analysis.

It is not clear whether treatment by vascular endothelial growth factor (VEGF) gene transfer can improve myocardial ischemia through a proangiogenesis mechanism and is effective against coronary artery disease (CAD). We aimed to perform a systematic review and meta-analysis of randomized controlled trials (RCTs) that compared VEGF gene therapy and standard treatments in CAD. We systematically searched the PubMed, Embase, and Cochrane databases and relevant references for RCTs (published up to May 2018; no language restrictions) and performed meta-analysis using both fixed and random effects models. Our primary outcome measures were mortality and serious cardiac events. The secondary outcome measures were follow-up left ventricular ejection fraction (LVEF), change in LVEF (ΔLVEF), and angina outcomes. The registration number is CRD42017058430. Of 524 identified studies, 14 were eligible and were included in our analysis. At a mean follow-up of 6months, VEGF gene therapy demonstrated a decreased risk of serious cardiac events (11.7% vs 21.2%, relative risk: 0.56; 95% confidence interval (CI): 0.37, 0.84; P=0.005) and a slight improvement in follow-up LVEF (weighted mean difference: 1.95; 95%CI: 1.28, 2.62). Furthermore, VEGF gene therapy using adenoviral vectors showed more potential benefit in terms of the risk of serious cardiac events, ΔLVEF, and Canadian Cardiovascular Society angina class. Nevertheless, mortality and angina frequency scores were not different. Vascular endothelial growth factor gene therapy appears to be safe and effective regarding serious cardiac events, with greater benefit when using adenoviral vectors. This meta-analysis highlights the need for further exploration in these areas.

The role of aspirin, heparin, and other interventions in the prevention and treatment of fetal growth restriction.

Fetal growth restriction and related placental pathologies such as preeclampsia, stillbirth, and placental abruption are believed to arise in early pregnancy when inadequate remodeling of the maternal spiral arteries leads to persistent high-resistance and low-flow uteroplacental circulation. The consequent placental ischaemia, reperfusion injury, and oxidative stress are associated with an imbalance in angiogenic/antiangiogenic factors. Many interventions have centered on the prevention and/or treatment of preeclampsia with results pertaining to fetal growth restriction and small-for-gestational-age pregnancy often included as secondary outcomes because of the common pathophysiology. This renders the study findings less reliable for determining clinical significance. For the prevention of fetal growth restriction, a recent large-study level meta-analysis and individual patient data meta-analysis confirm that aspirin modestly reduces small-for-gestational-age pregnancy in women at high risk (relative risk, 0.90, 95% confidence interval, 0.81-1.00) and that a dose of ≥100 mg should be recommended and to start at or before 16 weeks of gestation. These findings support national clinical practice guidelines. Invitro and invivo studies suggest that low-molecular-weight heparin may prevent fetal growth restriction; however, evidence from randomized control trials is inconsistent. A meta-analysis of multicenter trial data does not demonstrate any positive preventative effect of low-molecular-weight heparin on a primary composite outcome of placenta-mediated complications including fetal growth restriction (18% vs 18%; absolute risk difference, 0.6%; 95% confidence interval, 10.4-9.2); use of low-molecular-weight heparin for the prevention of fetal growth restriction should remain in the research setting. There are even fewer treatment options once fetal growth restriction is diagnosed. At present the only management option if the risk of hypoxia, acidosis, and intrauterine death is high is iatrogenic preterm birth, with the use of peripartum maternal administration of magnesium sulphate for neuroprotection and corticosteroids for fetal lung maturity, to prevent adverse neonatal outcomes. The pipeline of potential therapies use different strategies, many aiming to increase fetal growth by improving poor placentation and uterine blood flow. Phosphodiesterase type 5 inhibitors that potentiate nitric oxide availability such as sildenafil citrate have been extensively researched both in preclinical and clinical studies; results from the Sildenafil Therapy In Dismal Prognosis Early-Onset Intrauterine Growth Restriction consortium of randomized control clinical trials are keenly awaited. Targeting the uteroplacental circulation with novel therapeutics is another approach, the most advanced being maternal vascular endothelial growth factor gene therapy, which is being translated into the clinic via the doEs Vascular endothelial growth factor gene therapy safEly impRove outcome in seveRe Early-onset fetal growth reSTriction consortium. Other targeting approaches include nanoparticles and microRNAs to deliver drugs locally to the uterine arterial endothelium or trophoblast. Invitro and invivo studies and animal models have demonstrated effects of nitric oxide donors, dietary nitrate, hydrogen sulphide donors, statins, and proton pump inhibitors on maternal blood pressure, uteroplacental resistance indices, and angiogenic/antiangiogenic factors. Data from human pregnancies and, in particular, pregnancies with fetal growth restriction remain very limited. Early research into melatonin, creatine, and N-acetyl cysteine supplementation in pregnancy suggests they may have potential as neuro- and cardioprotective agents in fetal growth restriction.

EVERREST prospective study: a 6-year prospective study to define the clinical and biological characteristics of pregnancies affected by severe early onset fetal growth restriction

BackgroundFetal growth restriction (FGR) is a serious obstetric condition for which there is currently no treatment. The EVERREST Prospective Study has been designed to characterise the natural history of pregnancies affected by severe early onset FGR and establish a well phenotyped bio-bank. The findings will provide up-to-date information for clinicians and patients and inform the design and conduct of the EVERREST Clinical Trial: a phase I/IIa trial to assess the safety and efficacy of maternal vascular endothelial growth factor (VEGF) gene therapy in severe early onset FGR. Data and samples from the EVERREST Prospective Study will be used to identify ultrasound and/or biochemical markers of prognosis in pregnancies with an estimated fetal weight (EFW) <3rd centile between 20+0 and 26+6 weeks of gestation.MethodsThis is a 6 year European multicentre prospective cohort study, recruiting women with a singleton pregnancy where the EFW is <3rd centile for gestational age and <600 g at 20+0 to 26+6 weeks of gestation. Detailed data are collected on: maternal history; antenatal, peripartum, and postnatal maternal complications; health economic impact; psychological impact; neonatal condition, progress and complications; and infant growth and neurodevelopment to 2 years of corrected age in surviving infants. Standardised longitudinal ultrasound measurements are performed, including: fetal biometry; uterine artery, umbilical artery, middle cerebral artery, and ductus venosus Doppler velocimetry; and uterine artery and umbilical vein volume blood flow. Samples of maternal blood and urine, amniotic fluid (if amniocentesis performed), placenta, umbilical cord blood, and placental bed (if caesarean delivery performed) are collected for bio-banking. An initial analysis of maternal blood samples at enrolment is planned to identify biochemical markers that are predictors for fetal or neonatal death.DiscussionThe findings of the EVERREST Prospective Study will support the development of a novel therapy for severe early onset FGR by describing in detail the natural history of the disease and by identifying women whose pregnancies have the poorest outcomes, in whom a therapy might be most advantageous. The findings will also enable better counselling of couples with affected pregnancies, and provide a valuable resource for future research into the causes of FGR.Trial registrationNCT02097667 registered 31st October 2013.

VEGF gene therapy cooperatively recruits molecules from the immune system and stimulates cell homing and angiogenesis in refractory angina

BackgroundNew vessels are formed in response to stimuli from angiogenic factors, a process in which paracrine signaling is fundamental. ObjectiveTo investigate the cooperative paracrine signaling profile in response to Vascular Endothelial Growth Factor (VEGF) gene therapy in patients with coronary artery disease (CAD) and refractory angina. MethodA cohort study was conducted in which plasma was collected from patients who underwent gene therapy with a plasmid expressing VEGF 165 (10) and from surgical procedure controls (4). Blood samples were collected from both groups prior to baseline and on days 3, 9 and 27 after the interventions and subjected to systemic analysis of protein expression (Interleukin-6, IL-6; Tumor Necrosis Factor-α, TNF-α; Interleukin-10, IL-10; Stromal Derived Factor-1 α, SDF-1α; VEGF; Angiopoietin-1, ANGPT-1; and Endothelin-1, ET-1) using the enzyme-linked immunosorbent assay (ELISA). ResultsAnalysis showed an increase in proinflammatory IL-6 (p=0.02) and ET-1 (p=0.05) on day 3 after gene therapy and in VEGF (p=0.02) on day 9. A strong positive correlation was found between mobilization of endothelial progenitor cells and TNF-α on day 9 (r=0.71; p=0.03). Furthermore, a strong correlation between β-blockers, antiplatelets, and vasodilators with SDF-1α baseline in the group undergoing gene therapy was verified (r=0.74; p=0.004). ConclusionAnalysis of cooperative paracrine signaling after VEGF gene therapy suggests that the immune system cell and angiogenic molecule expression as well as the endothelial progenitor cell mobilization are time-dependent, influenced by chronic inflammatory process and continuous pharmacological treatment.

Ethics and social acceptability of a proposed clinical trial using maternal gene therapy to treat severe early-onset fetal growth restriction.

To evaluate the ethical and social acceptability of a proposed clinical trial using maternal uterine artery vascular endothelial growth factor (VEGF) gene therapy to treat severe early-onset fetal growth restriction (FGR) in pregnant women. We conducted a literature review on the ethics and legality of experimental treatments in pregnant women, in particular advanced therapeutics. Issues that were identified from the literature helped develop interview guides for semistructured, qualitative interviews, carried out in four European countries, with 34 key stakeholders (disability groups, professional bodies and patient support groups) and 24 women/couples who had experienced a pregnancy affected by severe early-onset FGR. The literature review identified two main questions: 'is it ethical to give a pregnant woman a potentially risky treatment from which she does not benefit directly?' and 'is it ethical to treat a condition of the unborn child, who may then be born with a serious disability when, without treatment, they would have died?'. The review concluded that there were no ethical or legal objections to the intervention, or to a trial of this intervention. Overall, respondents viewed the proposed trial in positive terms. Women were generally interested in participating in clinical trials that conferred a potential benefit to their unborn child. The risk of disability of the premature child was a concern, but not considered a major stumbling block for maternal VEGF gene therapy. This study did not identify any fundamental or insurmountable objections to a trial of maternal gene therapy for severe early-onset FGR. Copyright © 2016 ISUOG. Published by John Wiley & Sons Ltd.

Basic FGF or VEGF gene therapy corrects insufficiency in the intrinsic healing capacity of tendons

Tendon injury during limb motion is common. Damaged tendons heal poorly and frequently undergo unpredictable ruptures or impaired motion due to insufficient innate healing capacity. By basic fibroblast growth factor (bFGF) or vascular endothelial growth factor (VEGF) gene therapy via adeno-associated viral type-2 (AAV2) vector to produce supernormal amount of bFGF or VEGF intrinsically in the tendon, we effectively corrected the insufficiency of the tendon healing capacity. This therapeutic approach (1) resulted in substantial amelioration of the low growth factor activity with significant increases in bFGF or VEGF from weeks 4 to 6 in the treated tendons (p < 0.05 or p < 0.01), (2) significantly promoted production of type I collagen and other extracellular molecules (p < 0.01) and accelerated cellular proliferation, and (3) significantly increased tendon strength by 68–91% from week 2 after AAV2-bFGF treatment and by 82–210% from week 3 after AAV2-VEGF compared with that of the controls (p < 0.05 or p < 0.01). Moreover, the transgene expression dissipated after healing was complete. These findings show that the gene transfers provide an optimistic solution to the insufficiencies of the intrinsic healing capacity of the tendon and offers an effective therapeutic possibility for patients with tendon disunion.

Vascular Endothelial Growth Factor Gene Therapy Promotes Nerve Regeneration in a Sciatic Nerve Graft Model in Rats

Incomplete nerve regeneration after injuries to the peripheral nervous system remains a significant problem in clinical routine and raises the need for supportive strategies. In this study we examined the effect of VEGF-gene therapy on nerve recovery after an auto-graft implantation in a 2 cm sciatic nerve defect model in 18 rats, using an adenoviral vector encoding for VEGF165 (AdCMV.VEGF165) for gene transduction. Functional recovery was assessed weekly by gait analyses of the rats’ hind limbs. Morphometric evaluation including histology, axon counts, motor neuron counts and corrosion casting was carried out 18 weeks post-op. VEGF-treated animals contained a higher proportion of large axons in the distal part of the nerve grafts and the SFI (Sciatic Function Index) showed faster nerve regeneration (p<0.05). There was no change in the vascular architecture of the nerve grafts. These results indicate the positive impact of VEGF gene therapy on nerve recovery in the PNS. VEGF gene therapy led to a significant improvement of the motor-functional parameters and showed accelerated recovery at the histomorphological level. This effect does not seem to be due to better vascularization of the nerve grafts. The use of an adenoviral vector should be be viewed critically. Keywords: VEGF, nerve regeneration, gene therapy. Read more →

Vascular endothelial growth factor gene therapy improves nerve regeneration in a model of obstetric brachial plexus palsy

The treatment of obstetric brachial plexus palsy has been limited to conservative therapies and surgical reconstruction of peripheral nerves. In addition to the damage of the brachial plexus itself, it also leads to a loss of the corresponding motoneurons in the spinal cord, which raises the need for supportive strategies that take the participation of the central nervous system into account. Based on the protective and regenerative effects of VEGF on neural tissue, our aim was to analyse the effect on nerve regeneration by adenoviral gene transfer of vascular endothelial growth factor (VEGF) in postpartum nerve injury of the brachial plexus in rats. In the present study, we induced a selective crush injury to the left spinal roots C5 and C6 in 18 rats within 24 hours after birth and examined the effect of VEGF-gene therapy on nerve regeneration. For gene transduction an adenoviral vector encoding for VEGF165 (AdCMV.VEGF165) was used. In a period of 11 weeks, starting 3 weeks post-operatively, functional regeneration was assessed weekly by behavioural analysis and force measurement of the upper limb. Morphometric evaluation was carried out 8 months post-operatively and consisted of a histological examination of the deltoid muscle and the brachial plexus according to defined criteria of degeneration. In addition, atrophy of the deltoid muscle was evaluated by weight determination comparing the left with the right side. VEGF expression in the brachial plexus was quantified by an enzyme-linked immunosorbent assay (ELISA). Furthermore the motoneurons of the spinal cord segment C5 were counted comparing the left with the right side. On the functional level, VEGF-treated animals showed faster nerve regeneration. It was found less degeneration and smaller mass reduction of the deltoid muscle in VEGF-treated animals. We observed significantly less degeneration of the brachial plexus and a greater number of surviving motoneurons (P < 0·05) in the VEGF group. The results of this study confirmed the positive effect of VEGF-gene therapy on regeneration and survival of nerve cells. We could demonstrate a significant improvement on the motor-functional as well as on the histomorphological level. However, increased vascularization of the nerve tissue caused by VEGF does not seem to be the major reason for these effects. The clinical use of adenoviral VEGF-gene therapy in the newborn cannot be justified so far.

P14.27: Ethics and ethical evaluation of a proposed clinical trial with maternal uterine artery vascular endothelial growth factor gene therapy to treat severe early‐onset fetal growth restriction in pregnant women

<scp>P</scp>14.27: Ethics and ethical evaluation of a proposed clinical trial with maternal uterine artery vascular endothelial growth factor gene therapy to treat severe early‐onset fetal growth restriction in pregnant women

PFM.08 Ethics and ethical evaluation of a proposed clinical trial with maternal uterine artery vascular endothelial growth factor gene therapy to treat severe early-onset fetal growth restriction in pregnant women

The EVERREST programme proposes a clinical trial with maternal uterine artery vascular endothelial growth factor gene therapy to treat severe early-onset fetal growth restriction (FGR) in pregnant women. FGR is...

Treatment of poor placentation and the prevention of associated adverse outcomes--what does the future hold?

ABSTRACTPoor placentation, which manifests as pre-eclampsia and fetal growth restriction, is a major pregnancy complication. The underlying cause is a deficiency in normal trophoblast invasion of the spiral arteries, associated with placental inflammation, oxidative stress, and an antiangiogenic state. Peripartum therapies, such as prenatal maternal corticosteroids and magnesium sulphate, can prevent some of the adverse neonatal outcomes, but there is currently no treatment for poor placentation itself. Instead, management relies on identifying the consequences of poor placentation in the mother and fetus, with iatrogenic preterm delivery to minimise mortality and morbidity. Several promising therapies are currently under development to treat poor placentation, to improve fetal growth, and to prevent adverse neonatal outcomes. Interventions such as maternal nitric oxide donors, sildenafil citrate, vascular endothelial growth factor gene therapy, hydrogen sulphide donors, and statins address the underlying pathology, while maternal melatonin administration may provide fetal neuroprotection. In the future, these may provide a range of synergistic therapies for pre-eclampsia and fetal growth restriction, depending on the severity and gestation of onset.

Gene Therapy Briefs

Human Gene TherapyVol. 25, No. 1 BriefsGene Therapy BriefsAlex PhilippidisAlex PhilippidisSearch for more papers by this authorPublished Online:20 Jan 2014https://doi.org/10.1089/hum.2013.2526AboutSectionsView articleView Full TextPDF/EPUB Permissions & CitationsPermissionsDownload CitationsTrack CitationsAdd to favorites Back To Publication ShareShare onFacebookTwitterLinked InRedditEmail View articleFiguresReferencesRelatedDetailsCited byPhase I/II Gene Therapy Trial of Fanconi Anemia Patients with a New Orphan Drug Consisting of a Lentiviral Vector Carrying the FANCA Gene: A Coordinated International Action (EuroFancolen)18 June 2015 | Human Gene Therapy Clinical Development, Vol. 26, No. 2Does Vascular Endothelial Growth Factor Gene Therapy Safely Improve Outcome in Severe Early-Onset Fetal Growth Restriction? (EVERREST)18 June 2015 | Human Gene Therapy Clinical Development, Vol. 26, No. 2 Volume 25Issue 1Jan 2014 InformationCopyright 2014, Mary Ann Liebert, Inc.To cite this article:Alex Philippidis.Gene Therapy Briefs.Human Gene Therapy.Jan 2014.12-16.http://doi.org/10.1089/hum.2013.2526Published in Volume: 25 Issue 1: January 20, 2014PDF download

Effect of vegf gene therapy and hyaluronic acid film sheath on peripheral nerve regeneration

Functional nerve regeneration after reconstructive nerve surgery remains unsatisfying. In this study, vascular endothelial growth factor (VEGF) gene therapy combined with a hyaluronic acid (HA)-enriched microenvironment in nerve regeneration was investigated. Sciatic nerve was transected, and end-to-end neurorrhaphy was performed on 32 male Sprague-Dawley rats, which were randomly divided into four groups (n = 8 per group): nerve coaptation without treatment (group I); nerve coaptation covered with HA film sheath (group II); nerve coaptation with intramuscular VEGF gene in plasmid injection (group III); and nerve coaptation combined with HA film sheath and intramuscular VEGF gene in plasmid injection (group IV). Contralateral sciatic nerves were used as control. VEGF expression was verified from gluteal muscle biopsies surrounding the sciatic nerve by reverse transcriptase-PCR. Electrophysiological, histopathological, and electron microscopic evaluations were performed after 4 weeks. Mean peak amplitude of groups I-IV and nonoperated sciatic nerve were 4.5 ± 0.6 mV, 6.4 ± 0.4 mV, 6.7 ± 0.5 mV, 8.5 ± 0.4 mV, and 9.8 ± 0.5 mV, respectively. Mean myelinated axonal counts of groups I-IV and nonoperated sciatic nerve were 105 ± 24, 165 ± 19, 181 ± 22, 271 ± 23, and 344 ± 17, respectively. Treatment with HA film sheath coverage combined with intramuscular VEGF gene in plasmid injection yielded statistically significant higher peak amplitudes and myelinated axonal counts (P < 0.001). In addition, significantly less scar formation with HA administration (groups II and IV; P < 0.001) was found. Thus, it was found that VEGF might crucially regulate nerve regeneration processes and that HA can reduce the scar formation. This study showed that the combination of HA film sheath and VEGF gene may synergistically promote peripheral nerve regeneration.

Effect of vascular endothelial growth factor gene therapy on post-traumatic peripheral nerve regeneration and denervation-related muscle atrophy

Functional recovery after peripheral nerve injury depends on both improvement of nerve regeneration and prevention of denervation-related skeletal muscle atrophy. To reach these goals, in this study we overexpressed vascular endothelial growth factor (VEGF) by means of local gene transfer with adeno-associated virus (AAV). Local gene transfer in the regenerating peripheral nerve was obtained by reconstructing a 1-cm-long rat median nerve defect using a vein segment filled with skeletal muscle fibers that have been previously injected with either AAV2-VEGF or AAV2-LacZ, and the morphofunctional outcome of nerve regeneration was assessed 3 months after surgery. Surprisingly, results showed that overexpression of VEGF in the muscle-vein-combined guide led to a worse nerve regeneration in comparison with AAV-LacZ controls. Local gene transfer in the denervated muscle was obtained by direct injection of either AAV2-VEGF or AAV2-LacZ in the flexor digitorum sublimis muscle after median nerve transection and results showed a significantly lower progression of muscle atrophy in AAV2-VEGF-treated muscles in comparison with muscles treated with AAV2-LacZ. Altogether, our results suggest that local delivery of VEGF by AAV2-VEGF-injected transplanted muscle fibers do not represent a rational approach to promote axonal regeneration along a venous nerve guide. By contrast, AAV2-VEGF direct local injection in denervated skeletal muscle significantly attenuates denervation-related atrophy, thus representing a promising strategy for improving the outcome of post-traumatic neuromuscular recovery after nerve injury and repair.

Post-translational regulation of a hypoxia-responsive VEGF plasmid for the treatment of myocardial ischemia

Vascular endothelial growth factor (VEGF) gene therapy to promote therapeutic angiogenesis has been advanced as an alternative treatment for myocardial ischemia. The unregulated expression of VEGF and the use of viral vectors, however, have slowed the clinical development of angiogenic gene therapy. The development of clinically beneficial angiogenic gene therapy requires a disease-specific gene expression system and an efficient non-viral gene carrier. To address these requirements, we developed a new post-translationally regulated hypoxia-responsible VEGF plasmid, pβ-SP-ODD-VEGF, and a dendrimer-type bio-reducible polymer, PAM-ABP. The efficacy of VEGF gene therapy with the PAM-ABP/pβ-SP-ODD-VEGF was evaluated and compared to the RTP-VEGF plasmid, a previously constructed hypoxia-inducible plasmid, in an ischemia/reperfusion (I/R) rat model. Cine magnetic resonance imaging was used to analyze the ischemia/reperfusion rats treated with either the PAM-ABP/pβ-SP-ODD-VEGF or the PAM-ABP/RTP-VEGF. The PAM-ABP/pβ-SP-ODD-VEGF treatment more effectively protected cardiomyocytes against apoptosis, preserved left ventricular (LV) function, and prevented LV remodeling compared to the PAM-ABP/RTP-VEGF-treated rats. These results suggest that the pβ-SP-ODD-VEGF with PAM-ABP may be efficacious in the treatment of acute ischemic heart disease.