title: Long-term inhibition of the central alpha(2B)-adrenergic receptor gene via recombinant AAV-delivered antisense in hypertensive rats.
abstract: BACKGROUND
  Salt-induced hypertension is mediated via the alpha(2B)-adrenergic receptor (AR) subtype. In alpha(2B)-AR gene knockout mice, blood pressure (BP) does not rise with salt loading, and in rats with salt-induced hypertension, BP decreases transiently with antisense (AS) treatment targeting the alpha(2B)-AR gene. The present experiments were designed to explore the possibility of gene transfection in the brain by intracerebroventricular (ICV) delivery of AS-DNA via adeno-associated virus (AAV) to prolong alpha(2B)-AR inhibition and hence reversal of salt-dependent hypertension.
  
  
  METHODS
  A recombinant AAV (rAAV) vector preparation encoding the alpha(2B)-AS fragment (previously tested in vitro for inhibition of alpha(2B)-AR protein production in cells) and containing green fluorescence protein (GFP) for visualization was injected ICV into subtotally nephrectomized, salt-fed rats. Control rats received rAAV-GFP (n = 8 per group).
  
  
  RESULTS
  We observed that BP rose from a baseline of 120 +/- 10 to 184 +/- 12 mm Hg. Injection of rAAV-alpha(2B)-AS produced a 35 +/- 12 mm Hg fall in BP, lasting without evidence of diminishing for at least 16 days, whereas rAAV-GFP-injected rats showed a continued rise in BP. Rats treated with rAAV-alpha(2B)-AS treated had a 45% to 65% decrease in alpha(2B)-AR protein levels in key regulatory regions of the brain. Neither group had signs of immunologic response to the virus injection.
  
  
  CONCLUSIONS
  These results indicate that our construct, when given by ICV means, could reach multiple sites of the central nervous system relevant to BP regulation and could safely inhibit the central alpha(2B)-adrenergic receptor, thereby achieving prolonged reversal of salt-induced hypertension.
authors.affiliation: Hypertension and Atherosclerosis Section of the Department of Medicine, Boston University School of Medicine, Boston, Massachusetts 02118, USA. sherene@bu.edu
authors.forename: Sherene M
authors.initials: SM
authors.lastname: Shenouda
authors.forename: Conrado
authors.initials: C
authors.lastname: Johns
authors.forename: Ekaterina
authors.initials: E
authors.lastname: Kintsurashvili
authors.forename: Irene
authors.initials: I
authors.lastname: Gavras
authors.forename: Haralambos
authors.initials: H
authors.lastname: Gavras
mesh_terms: D058669:Adrenergic alpha-2 Receptor Antagonists; D000818:Animals; D015153:Blotting, Western; D002478:Cells, Cultured; D002490:Central Nervous System / Q000378:metabolism / Q000473:pathology; D016373:DNA, Antisense / Q000008:administration & dosage / Q000627:therapeutic use*; D000229:Dependovirus / Q000235:genetics*; D004195:Disease Models, Animal; D005786:Gene Expression Regulation; D015316:Genetic Therapy; D005822:Genetic Vectors; D049452:Green Fluorescent Proteins; D006973:Hypertension / Q000628:therapy*; D007150:Immunohistochemistry; D007276:Injections, Intraventricular; D008297:Male; D051379:Mice; D008856:Microscopy, Fluorescence; D010957:Plasmids; D051381:Rats; D017208:Rats, Wistar; D018341:Receptors, Adrenergic, alpha-2 / Q000235:genetics* / Q000378:metabolism; D014162:Transfection
chemical_list: C547772:Adra2b protein, mouse; D058669:Adrenergic alpha-2 Receptor Antagonists; D016373:DNA, Antisense; D018341:Receptors, Adrenergic, alpha-2; D049452:Green Fluorescent Proteins