Apolipoprotein E deficiency in mice: gene replacement and prevention of atherosclerosis using adenovirus vectors.

Abstract

Apolipoprotein E (apoE)-deficient mice develop marked hyperlipidemia as well as atherosclerosis and thus are an excellent animal model for evaluating the potential for gene therapy in human genetic dyslipoproteinemias. Recombinant adenovirus containing either human apoE (rAdv.apoE) or the reporter gene luciferase (rAdv.luc) were generated and infused intravenously in apoE-deficient mice with preinfusion plasma total cholesterol of 644±149 mg/dl and cholesterol rich VLDL/IDL. After a single infusion of rAdv.apoE, plasma concentrations of human apoE ranging from 1.5 to 650 mg/dl were achieved. Adenovirus-mediated apoE replacement resulted in normalization of the lipid and lipoprotein profile with markedly decreased total cholesterol (103±18 mg/dl), VLDL, IDL, and LDL, as well as increased HDL. Measurement of aortic atherosclerosis 1 mo after adenoviral infusion demonstrated a marked reduction in the mean lesion area of mice infused with rAdv.apoE (58±8 X 103 ,um2) when compared with control mice infused with rAdv.luc (161±19 X 103 ,um2; P < 0.0001). Thus, apoE expression for 4 wk was sufficient to markedly reduce atherosclerosis, demonstrating the feasibility of gene therapy for correction of genetic hyperlipidemias resulting in atherosclerosis. The combined use of adenovirus vectors and the apoE-deficient mouse represents a new in vivo approach that will permit rapid screening of candidate genes for the prevention of atherosclerosis. (J. Clin. Invest. 1995.

Treatment of severe hypercholesterolemia in apolipoprotein E-deficient mice by intramuscular injection of plasmid DNA

“…7,27,31 Alternatively, adenovirus-based gene transfer techniques have also been described. 8,9 Lastly, endothelial cells and epidermal keratinocytes expressing the apoE have also been used. 10,33 Because of its unique properties, skeletal muscle was chosen in our study as the target tissue for gene transfer.…”

“…7 Phenotypic reversion of the hypercholesterolemic state in apoEdeficient mice has been reported after in vivo gene transfer with an adenoviral vector containing human apoE cDNA. 8,9 Furthermore, cholesterol reduction has recently been demonstrated after transplantation of apoE secreting endothelial cells into apoE-deficient mice. 10 These findings highlight the great opportunity offered by apoE gene replacement.…”

A novel endothelial cell-based gene therapy platform for the in vivo delivery of apolipoprotein E

“…[34][35][36][38][39][40] Although adenovirus-based gene transfer strategies are powerful, they raise major safety concerns when envisioned for treating long-term human diseases such as atherosclerosis. 37 Also, gene expression from these vectors is only transient and strong immunological responses increase the risk of further injections.…”

“…In an alternative gene therapy approach, apoE deficiency was successfully corrected utilizing recombinant adenovirus vectors expressing human apoE. 36 Systemic delivery of adenoviruses expressing the human apoE to mouse liver was achieved and resulted in normalized plasma apoE levels. Significant reduction of aortic atherosclerotic mean lesion area was obtained when compared with control apoEdeficient mice.…”

Inhibition of atherosclerosis in apolipoprotein-E-deficient mice following muscle transduction with adeno-associated virus vectors encoding human apolipoprotein-E

“…18,19 Liver-directed somatic gene transfer with recombinant adenovirus vectors (rAds) containing the apoE3 cDNA has also been shown to result in transient normalisation of lipoprotein and cholesterol plasma profiles and inhibition of atherosclerotic lesion development. 20,21 ApoE2 is less efficient at correcting the hyperlipidaemic phenotype compared with apoE3, due to reduced efficiency in mediating lipoprotein plasma clearance and liver uptake, but nevertheless has been shown to exhibit residual anti-atherogenic activity and retardation of atherosclerotic lesion development in apoE -/-mice, following liver-and muscle-directed gene transfer. 22,23 A major limitation of studies utilising rAd vectors to mediate apoE gene transfer has been the induction of adverse host immune and inflammatory responses, 24,25 which lead to only transient transduction and to rapid target cell elimination.…”