Treatment of severe hypercholesterolemia in apolipoprotein E-deficient mice by intramuscular injection of plasmid DNA.
We report on systemic delivery and long-term biological effects of apolipoprotein E (apoE) obtained by intramuscular (i.m.) plasmid DNA injection. ApoE plays an important role in lipoprotein catabolism and apoE knock-out mice develop severe hypercholesterolemia and diffuse atherosclerosis. We have injected apoE-deficient mice with 80 microg of a plasmid vector (pCMV-E3) encoding the human apoE3 cDNA under the control of the CMV promoter-enhancer in both posterior legs. Local expression of the transgene was demonstrated throughout 16 weeks. Human apoE3 recombinant protein reached 0.6 ng/ml serum level. After i.m. injection of pCMV-E3 expression vector the mean serum cholesterol concentrations decreased from 439 +/- 57 mg/dl to 253 +/- 99 mg/dl (P < 0.05) 2 weeks after injection and persisted at a significantly reduced level throughout the 16 weeks observation period (P < 0.005). Serum cholesterol was unaffected and reached an absolute level of 636 +/- 67 mg/dl in control groups. Finally, injection of pCMV-E3 into apoE-deficient mice resulted in a redistribution of cholesterol content between lipoprotein fractions, with a marked decrease in VLDL, IDL and LDL cholesterol content and an increase in HDL cholesterol. These results demonstrate that severe hypercholesterolemia in apoE-deficient mice can be effectively reversed by i.m. DNA injection, and indicate that this approach could represent a useful tool to correct several hyperlipidemic conditions resulting in atherosclerosis.
Rinaldi
M
M
Laboratory for Molecular Medicine and Biotechnology, School of Medicine, Institute of Experimental Medicine, CNR, Rome, Italy.
Catapano
A L
AL
Parrella
P
P
Ciafrè
S A
SA
Signori
E
E
Seripa
D
D
Uboldi
P
P
Antonini
R
R
Ricci
G
G
Farace
M G
MG
Fazio
V M
VM
D000704:Analysis of Variance; D000818:Animals; D001057:Apolipoproteins E / Q000172:deficiency* / Q000235:genetics* / Q000378:metabolism; D002784:Cholesterol / Q000097:blood; D003587:Cytomegalovirus / Q000235:genetics; D018076:DNA, Complementary / Q000008:administration & dosage*; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods; D015870:Gene Expression; D015316:Genetic Therapy / Q000379:methods*; D005822:Genetic Vectors / Q000008:administration & dosage*; D007273:Injections, Intramuscular; D008074:Lipoproteins / Q000097:blood; D051379:Mice; D008810:Mice, Inbred C57BL; D018482:Muscle, Skeletal / Q000737:chemistry / Q000378:metabolism; D011401:Promoter Regions, Genetic; D012333:RNA, Messenger / Q000032:analysis; D020133:Reverse Transcriptase Polymerase Chain Reaction
D001057:Apolipoproteins E; D018076:DNA, Complementary; D008074:Lipoproteins; D012333:RNA, Messenger; D002784:Cholesterol