Faculty Collaboration Database

Studies on the expression of genes encoding apolipoproteins B100 and B48 and the low density lipoprotein receptor in nonhuman primates. Comparison of dietary fat and cholesterol. J Biol Chem 1989 May 25;264(15):9039-45

Date

05/25/1989

Pubmed ID

2722816

Scopus ID

2-s2.0-0024403463 (requires institutional sign-in at Scopus site)   136 Citations

Abstract

African green monkeys were fed diets containing low and moderate cholesterol concentrations with either polyunsaturated or unsaturated fat as 40% of calories. Plasma total cholesterol, low density lipoprotein (LDL) cholesterol, and apoB concentrations generally were higher in animals fed (a) the higher dietary cholesterol concentration and (b) saturated fat. At necropsy, liver and intestine were removed, and measurement of mRNAs for LDL receptors (liver) and for apolipoprotein B (liver and intestine) was done. Monkey small intestine mucosa made exclusively apoB48 while the liver made only apoB100, although apoB mRNA in both tissues was the same size (14 kilobases). No dietary cholesterol or fat effects were found for apoB mRNA abundance in the liver, while the animals fed the higher dietary cholesterol level had 50% lower levels of hepatic LDL receptor mRNA. In a separate group of animals, livers were perfused and the rate of apoB secretion was measured. No dietary fat effect on apoB secretion rate was found, and no relationship between plasma LDL cholesterol concentration and the rate of hepatic apoB production existed. These findings support the idea that the dietary factors that increase LDL concentrations act by reducing clearance of apoB-containing particles rather than by increasing production of these lipoproteins. Hepatic LDL receptor mRNA was similar in abundance in polyunsaturated fat and saturated fat-fed animals, suggesting that the difference in plasma cholesterol concentration between these groups is not mediated via effects on LDL receptor mRNA abundance. The level of intestinal apoB mRNA was about 30% higher in animals fed the moderate dietary cholesterol concentration. Earlier studies have shown that more cholesterol is transported in chylomicrons from the intestine when dietary cholesterol levels are higher, and the increased intestinal apoB mRNA abundance may reflect increased intestinal cholesterol transport and chylomicron apoB48 production.

Author List

Sorci-Thomas M, Wilson MD, Johnson FL, Williams DL, Rudel LL

Author

Mary Sorci Thomas PhD Professor in the Medicine department at Medical College of Wisconsin

MESH terms used to index this publication - Major topics in bold

Animals
Apolipoprotein B-100
Apolipoprotein B-48
Apolipoproteins B
Cholesterol, Dietary
Dietary Fats
Female
Gene Expression Regulation
Genes
Intestinal Mucosa
Intestine, Small
Lipoproteins, LDL
Liver
Male
RNA, Messenger
Receptors, LDL
Reference Values
Transcription, Genetic