ADENOVIRUS-MEDIATED GENE-TRANSFER OF HUMAN LIPOPROTEIN-LIPASE AMELIORATES THE HYPERLIPIDEMIAS ASSOCIATED WITH APOLIPOPROTEIN-E AND LDL RECEPTOR DEFICIENCIES IN MICE
E. Zsigmond et al., ADENOVIRUS-MEDIATED GENE-TRANSFER OF HUMAN LIPOPROTEIN-LIPASE AMELIORATES THE HYPERLIPIDEMIAS ASSOCIATED WITH APOLIPOPROTEIN-E AND LDL RECEPTOR DEFICIENCIES IN MICE, Human gene therapy, 8(16), 1997, pp. 1921-1933
Lipoprotein lipase (LPL) is the rate-limiting enzyme for the hydrolysi
s of triglyceride-rich lipoproteins. We tested the efficacy of adenovi
rus-mediated gene transfer of LPL as treatment of experimental hyperli
pidemias associated with apolipoprotein (apoE) deficiency (apoE-/-) an
d low-density lipoprotein receptor (LDLr) deficiency (LDLr-/-) in mice
. Replication-defective adenovirus containing the human LPL cDNA drive
n by a cytomegalovirus promoter (Ad.hLPL) efficiently transduced CHO-l
dlA7 cells in vitro, inducing in these cells the production of bioacti
ve LPL (73 mU/ml). Intravenous injection of Ad.hLPL (2 x 10(9) pfu) le
d to high-level expression of hLPL mRNA and LPL activity in the liver
(88.3 mU/ml) and in post-heparin plasma (116.1 mU/ml). Overexpression
of LPL resulted in marked reductions in total plasma cholesterol (TC;
48%, 43%, 25%) and triglycerides (TTg; 63%, 40%, 70%, p < 0.01) in apo
E-/-, LDLr-/-, and wild-type (WT) mice, respectively. Fast protein liq
uid chromatography (FPLC) fractionation of plasma lipoproteins showed
a marked decrease in very-low-density lipoprotein (VLDL)/chylomicron r
emnant, cholesterol (V/CR-C) in apoE-/-(83%), LDLr-/- (84%), and WT mi
ce (58%, p < 0.01). VLDL/chylomicron remnant triglycerides (V/CR-Tg) w
ere virtually eliminated in apoE-/-(92%), LDLr-/-(86%), and WT mice (8
4%, p < 0.05). No significant changes were detected in LPL activities,
plasma lipids, or lipoproteins of mice injected with a control virus,
Ad.Luc, containing the luciferase instead of the LPL cDNA. In summary
, infusion of Ad.hLPL leads to increased liver and post-heparin plasma
LPL activities, significantly reduced TC, TTg, V/CR-C, and V/CR-Tg in
WT mice, as well as in mice with apoE and LDLr deficiencies. Adenovir
us-mediated LPL gene transfer to the liver is an effective means of re
versing many of the lipoprotein abnormalities in apoE- and LDLr-defici
ent mice.