No abstract

Efficient and widespread gene transfer is required for successful treatment of Duchenne muscular dystrophy (DMD). Here, we performed the first clinical trial using a chimeric adeno-associated virus (AAV) capsid variant (designated AAV2.5) derived from a rational design strategy. AAV2.5 was generated from the AAV2 capsid with five mutations from AAV1. The novel chimeric vector combines the improved muscle transduction capacity of AAV1 with reduced antigenic crossreactivity against both parental serotypes, while keeping the AAV2 receptor binding. In a randomized double-blind placebo-controlled phase I clinical study in DMD boys, AAV2.5 vector was injected into the bicep muscle in one arm, with saline control in the contralateral arm. A subset of patients received AAV empty capsid instead of saline in an effort to distinguish an immune response to vector versus minidystrophin transgene. Recombinant AAV genomes were detected in all patients with up to 2.56 vector copies per diploid genome. There was no cellular immune response to AAV2.5 capsid. This trial established that rationally designed AAV2.5 vector was safe and well tolerated, lays the foundation of customizing AAV vectors that best suit the clinical objective (e.g., limb infusion gene delivery) and should usher in the next generation of viral delivery systems for human gene transfer.

No abstract

Despite substantial evidence that nitric oxide (NO) and/or endogenous S-nitrosothiols (SNOs) exert protective effects in a variety of cardiovascular diseases, the molecular details are largely unknown. Here we show that following left coronary artery ligation, mice with a targeted deletion of the S-nitrosoglutathione reductase gene (GSNOR ؊/؊ ) have reduced myocardial infarct size, preserved ventricular systolic and diastolic function, and maintained tissue oxygenation. These profound physiological effects are associated with increases in myocardial capillary density and S-nitrosylation of the transcription factor hypoxia inducible factor-1␣ (HIF-1␣) under normoxic conditions. We further show that S-nitrosylated HIF-1␣ binds to the vascular endothelial growth factor (VEGF) gene, thus identifying a role for GSNO in angiogenesis and myocardial protection. These results suggest innovative approaches to modulate angiogenesis and preserve cardiac function.angiogenesis ͉ HIF-1␣ ͉ myocardial infarction ͉ nitric oxide ͉ S-nitrosylation

Objectives Heart failure (HF) is characterized by perturbations in energy homeostasis and metabolism. The reversibility and prognostic value of circulating markers reporting on these changes remain unclear. We sought to describe the metabolomic profiles of patients along the spectrum of systolic HF, determine their association with adverse outcomes in a clinical trial of HF, and evaluate whether identified metabolites change with treatment for end-stage systolic HF. Methods To assess association of metabolites with clinical outcomes, a population of 453 chronic systolic HF patients who participated in the HF-ACTION trial, which randomized ambulatory, stable patients to exercise training versus usual care, were included. To assess change in metabolites with mechanical circulatory support, 41 patients with end-stage HF who underwent left ventricular assist device (LVAD) placement were studied. Targeted, quantitative profiling of 60 metabolites using tandem flow injection mass spectrometry was performed on frozen plasma samples obtained prior to randomization in the HF-ACTION group, as well as, prior to and ≥90 days post placement in the LVAD group. Principal components analysis (PCA) was used for data reduction; linear regression and Cox-proportional hazards regression modeling were used to assess the relation between the PCA-derived metabolite factor levels and clinical outcomes among patients from the HF-ACTION study. Differences between metabolite factors associated with outcomes in the HF-ACTION and LVAD groups were assessed using Wilcoxon rank sum tests. Results Five PCA-derived factors were significantly associated with peak VO2 levels at baseline in fully adjusted models. Of these, Factor 5 (composed of long-chain acylcarnitines) was associated with increased risk of all 3 pre-specified HF-ACTION clinical outcomes: all-cause mortality/all-cause hospitalization (HR: 1.24; 95% CI 1.09–1.42), all cause-hospitalization (HR: 1.42; 95% CI 1.16–1.74), and cardiovascular death or cardiovascular hospitalization (HR: 1.22; CI 1.06–1.39). Individual components of Factor 5 (C16, C18:1, and C18:2 acylcarnitine metabolites) were significantly higher in patients with end-stage HF prior to LVAD placement and decreased significantly after LVAD therapy. Conclusions In chronic HF patients, circulating long chain acylcarnitine metabolite levels were independently associated with clinical outcomes and decreased after long-term mechanical circulatory support. These metabolites, which report on mitochondrial fatty acid β-oxidation, highlight pathways that may serve as potential targets for new diagnostics or therapeutic interventions.