title: Long-term effect of neuronal nitric oxide synthase over-expression on cardiac neurotransmission mediated by a lentiviral vector.
abstract: Short-term over-expression of neuronal nitric oxide synthase (nNOS) with adenoviral gene transfer into peripheral cardiac autonomic neurons can facilitate cholinergic neurotransmission, and inhibit sympathetic transmission, by regulating cyclic nucleotide-dependent pathways coupled to neuronal calcium entry. We tested the idea whether cardiac neuromodulation by nNOS could be sustained by long-term over-expression of the enzyme following lentiviral gene transfer. We developed a lentiviral vector with an elongation factor 1 (EF1alpha) promoter to drive nNOS or enhanced green fluorescent protein (eGFP) expression. Lenti.EF1alpha-nNOS or Lenti.EF1alpha-eGFP was transferred to the right atrium of Spague-Dawley (SD) rats and acetylcholine (ACh) or noradrenaline (NA) release to field stimulation was measured 4 months after gene transfer. Atria transduced with Lenti.EF1alpha-nNOS had higher nNOS expression compared to the atria treated with Lenti.EF1alpha-eGFP (P < 0.05). We also detected significant increases (P < 0.05) in atrial cGMP and cAMP levels in the same tissue. Immunohistochemistry revealed co-localisation of eGFP in intrinsic cholinergic neurons (choline acetyltransferase positive) and intrinsic adrenergic neurons (tyrosine hydroxylase positive) following gene transfer. nNOS-transduced animals displayed enhanced ACh release (P < 0.05) and reduced NA release (P < 0.05) compared to the eGFP-treated group. nNOS-specific inhibition reversed the enhanced ACh release. Persistent nNOS over-expression mediated by a lentiviral vector can modulate sympatho-vagal control of cardiac excitability. This approach may provide a new tool to target impaired cardiac autonomic phenotypes that are disrupted by several cardiovascular pathologies.
authors.affiliation: Burdon Sanderson Cardiac Science Centre, Department of Physiology, Anatomy & Genetics, University of Oxford Parks Road, Oxford, UK.
authors.forename: Lijun
authors.initials: L
authors.lastname: Wang
authors.forename: Dan
authors.initials: D
authors.lastname: Li
authors.forename: Tom A
authors.initials: TA
authors.lastname: Dawson
authors.forename: David J
authors.initials: DJ
authors.lastname: Paterson
mesh_terms: D000200:Action Potentials / Q000502:physiology*; D000818:Animals; D005822:Genetic Vectors / Q000235:genetics; D006321:Heart / Q000294:innervation* / Q000502:physiology*; D016086:Lentivirus / Q000235:genetics; D017774:Long-Term Potentiation / Q000502:physiology*; D009474:Neurons / Q000502:physiology*; D052248:Nitric Oxide Synthase Type I / Q000235:genetics / Q000378:metabolism*; D051381:Rats; D017207:Rats, Sprague-Dawley; D055647:Rats, Transgenic; D009435:Synaptic Transmission / Q000502:physiology*; D015854:Up-Regulation
chemical_list: D052248:Nitric Oxide Synthase Type I