Increased incorporation of dietary plant sterols and cholesterol correlates with decreased expression of hepatic and intestinal Abcg5 and Abcg8 in diabetic BB rats

• Published in: The Journal of nutritional biochemistry Vol. 20; no. 3; pp. 177 - 186
• Main Authors: Scoggan, Kylie A., Gruber, Heidi, Chen, Qixuan, Plouffe, Louise J., Lefebvre, Jaclyn M., Wang, Bingtuan, Bertinato, Jesse, L'Abbé, Mary R., Hayward, Stephen, Ratnayake, W.M. Nimal
• Format: Journal Article
• Language: English
• Published: New York, NY Elsevier Inc 01-03-2009; New York, NY: Elsevier Science; Elsevier
• Subjects: ABC transporters; Animals; ATP Binding Cassette Transporter, Sub-Family G, Member 5; ATP Binding Cassette Transporter, Sub-Family G, Member 8; ATP-Binding Cassette Transporters - biosynthesis; BioBreeding rats; Biological and medical sciences; cholesteremic effect; Cholesterol, Dietary - pharmacology; Cholesterol-regulatory genes: Abcg5, Abcg8, Abca1, Npc1l1, Lxrα, Lxrβ, Srebp2, Hmgcr; Diabetes Mellitus, Type 1 - metabolism; diet; Dietary Fats - pharmacology; Feeding. Feeding behavior; Fundamental and applied biological sciences. Psychology; Gene Expression - drug effects; hormone receptors; hypercholesterolemia; insulin-dependent diabetes mellitus; Intestine, Small - drug effects; Intestine, Small - metabolism; intestines; Lipoproteins - biosynthesis; liver; Liver - drug effects; Liver - metabolism; Membrane Transport Proteins - metabolism; messenger RNA; nutrition-genotype interaction; phytosterols; Phytosterols - pharmacology; Plant stanols; Plant sterols; plant-based foods; Polymerase Chain Reaction; Rats; Rats, Inbred BB; regulator genes; RNA, Messenger - metabolism; Type 1 diabetes; Vertebrates: anatomy and physiology, studies on body, several organs or systems; BB; BioBreeding rats; Cholesterol-regulatory genes: Abcg5, Abcg8, Abca1, Npc1l1, Lxrα, Lxrβ, Srebp2, Hmgcr; Srebp2; Npc1l1; Lxrβ; Lxrα; Abca1; Abcg8; Abcg5; Type 1 diabetes; Plant sterols; Hmgcr; Plant stanols; Endocrinopathy; Incorporation; Rat; Liver; Lipids; Autoimmune disease; Plant; Hmgcr; Plant stanols; Plant sterols; Type 1 diabetes; Gene; Immunopathology; BioBreeding rats; Cholesterol-regulatory genes: Abcg5; Digestive system; Rodentia; Gut; Gene expression; Cholesterol; Abcal; Vertebrata; Mammalia; Animal; Sterol
• ISSN: 0955-2863; 1873-4847
• DOI: 10.1016/j.jnutbio.2008.01.011

The aim of this study was to determine the impact of dietary plant sterols and stanols on sterol incorporation and sterol-regulatory gene expression in insulin-treated diabetic rats and nondiabetic control rats. Diabetic BioBreeding (BB) and control BB rats were fed a control diet or a diet supplemented with plant sterols or plant stanols (5 g/kg diet) for 4 weeks. Expression of sterol-regulatory genes in the liver and intestine was assessed by real-time quantitative polymerase chain reaction. Diabetic rats demonstrated increased tissue accumulation of cholesterol and plant sterols and stanols compared to control rats. This increase in cholesterol and plant sterols and stanols was associated with a marked decrease in hepatic and intestinal
Abcg5 (ATP-binding cassette transporter G5) and
Abcg8 (ATP-binding cassette transporter G8) expressions in diabetic rats, as well as decreased mRNA levels of several other genes involved in sterol regulation. Plant sterol or plant stanol supplementation induced the accumulation of plant sterols and stanols in tissues in both rat strains, but induced a greater accumulation of plant sterols and stanols in diabetic rats than in control rats. Surprisingly, only dietary plant sterols decreased cholesterol levels in diabetic rats, whereas dietary plant stanols caused an increase in cholesterol levels in both diabetic and control rats. Therefore, lower expression levels of
Abcg5/
Abcg8 in diabetic rats may account for the increased accumulation of plant sterols and cholesterol in these rats.