Partial transfection of liver with a synthetic cholesterol 7 alpha-hydroxylase transgene is sufficient to stimulate the reduction of cholesterol in the plasma of hypercholesterolemic mice.
The effect of administering a synthetic transgene encoding cholesterol 7 alpha-hydroxylase (cyp7) on plasma cholesterol metabolism of intact mice was investigated. The synthetic cyp7 transgene (Tg1) was constructed by placing the cDNA sequence encoding the full-length cyp7 polypeptide under the control of a heavy metal inducible metallothionein promoter. The transgene was complexed with asialoorosomucoid-polylysine conjugate and introduced into mice via the tail vein. Cell marking experiments using a beta-galactosidase (lacZ) transgene as a tag showed that 5-10% of the liver can be transfected by this procedure. Administration of the Tg1 transgene to older hypercholesterolemic chow-fed mice resulted in about a 50% reduction of plasma cholesterol, regardless of whether or not transgene expression was induced by zinc treatment. In diet-induced hypercholesterolemic mice, the reduction (20%) in total plasma cholesterol was seen only when transgene expression was induced, and this reduction was due primarily to a decrease in non-high-density lipoprotein cholesterol. The maximum reduction was evident at 6 days after the introduction of the transgene and was no longer evident after 9 days. Introduction of the Tg1 transgene into young chow-fed mice had no effect on the already low levels of plasma cholesterol. However, compared with the no-transgene and lacZ transgene controls, the gallbladder bile acid content of Tg1-treated mice was increased. The results show that non-viral-mediated delivery of a synthetic transgene encoding cyp7 to a subpopulation of hepatocytes in the liver of intact hypercholesterolemic mice is sufficient to facilitate the temporary reduction of plasma cholesterol content.
Agellon
L B
LB
Department of Biochemistry, University of Alberta, Edmonton, Canada. luis.agellon@ualberta.ca
D000284:Administration, Oral; D000818:Animals; D002784:Cholesterol / Q000097:blood* / Q000235:genetics* / Q000378:metabolism; D002790:Cholesterol 7-alpha-Hydroxylase / Q000008:administration & dosage / Q000235:genetics* / Q000502:physiology; D004041:Dietary Fats / Q000008:administration & dosage; D005260:Female; D006937:Hypercholesterolemia / Q000097:blood / Q000188:drug therapy* / Q000235:genetics*; D008099:Liver / Q000378:metabolism*; D051379:Mice; D051381:Rats; D014162:Transfection / Q000379:methods*; D019076:Transgenes
D004041:Dietary Fats; D002784:Cholesterol; D002790:Cholesterol 7-alpha-Hydroxylase