title: Adeno-associated virus serotypes 7 and 8 outperform serotype 9 in expressing atheroprotective human apoE3 from mouse skeletal muscle.
abstract: Intramuscular injection of adeno-associated viral (AAV) vectors is potentially a safe, minimally invasive procedure for the long-term gene expression of circulating antiatherogenic proteins. Here, we compare secretion and atheroprotective effects of human apoE3 after injection of 3 pseudotyped AAV vectors (AAV2/7, AAV2/8, or AAV2/9), driven by the CMV enhancer/chicken β-actin (CAG) promoter, into skeletal muscle of hyperlipidemic apolipoprotein E-deficient (apoE⁻/⁻) mice. Vector viabilities were verified by transducing cultured C2C12 mouse myotubes and assessing secretion of human apoE3 protein. Both hind limb tibialis anterior muscles of female C57BL/6 apoE⁻/⁻ mice, 2 months old and fed a high-fat diet, were each injected with 1 x 10¹⁰ vector genomes of AAV vector. Identical noninjected mice served as controls; and blood was collected at weeks 0, 1, 2, 4, and 13. At termination (13 weeks), the brachiocephalic artery was excised; and after staining sections, plaque morphometry and fractional lipid content were quantified by computerized image analysis. Intramuscular injection of AAV2/7 and AAV2/8 vectors produced up to 2 μg human apoE3 per milliliter plasma, just below the threshold to reverse dyslipoproteinemia. AAV2/9 was notably less effective, mice having a 3-fold lower level of plasma apoE3 at 13 weeks and a 50% greater burden of atherosclerotic plaque lipid in their brachiocephalic arteries. We conclude that although vector refinement is needed to exploit fully apoE3 atheroprotective functions, AAV2/7 and AAV2/8 are promising gene transfer vectors for muscle-based expression of antiatherogenic circulating proteins.
authors.affiliation: Division of Medicine, UCL Medical School, NW32PF London, UK.
authors.forename: Vanessa C
authors.initials: VC
authors.lastname: Evans
authors.forename: Ian R
authors.initials: IR
authors.lastname: Graham
authors.forename: Takis
authors.initials: T
authors.lastname: Athanasopoulos
authors.forename: Deborah J
authors.initials: DJ
authors.lastname: Galley
authors.forename: Christopher L
authors.initials: CL
authors.lastname: Jackson
authors.forename: Jonathan Paul
authors.initials: JP
authors.lastname: Simons
authors.forename: George
authors.initials: G
authors.lastname: Dickson
authors.forename: James S
authors.initials: JS
authors.lastname: Owen
mesh_terms: D000818:Animals; D053318:Apolipoprotein E3 / Q000235:genetics* / Q000378:metabolism*; D050197:Atherosclerosis / Q000378:metabolism / Q000517:prevention & control*; D002460:Cell Line; D002536:Cerebral Arteries / Q000473:pathology; D003470:Culture Media; D000229:Dependovirus / Q000145:classification / Q000235:genetics* / Q000276:immunology; D004797:Enzyme-Linked Immunosorbent Assay; D015316:Genetic Therapy; D005822:Genetic Vectors; D006801:Humans; D006937:Hypercholesterolemia / Q000628:therapy; D050356:Lipid Metabolism / Q000235:genetics; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D018482:Muscle, Skeletal / Q000378:metabolism*; D012703:Serotyping; D014161:Transduction, Genetic
chemical_list: D053318:Apolipoprotein E3; D003470:Culture Media