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Integrative Physiology/Experimental Medicine |
From the Department of Pathology and Laboratory Medicine (B.B., K.N., J.C., V.H.-R., G.T., A.W., J.F., J.D., D.B., T.T., G.O., C.W.), Child and Family Research Institute, University of British Columbia, Vancouver, Canada; ICapture Centre (L.M., B.M.), University of British Columbia, Vancouver, Canada; the Department of Pediatrics (B.C., R.D., S.I.), Child and Family Research Institute, University of British Columbia, Vancouver, Canada; and the Department of Clinical Pharmacology (D.L.), University of Bonn, Germany.
Correspondence to Dr Cheryl L. Wellington, Department of Pathology and Laboratory Medicine, University of British Columbia, 980 West 28th Avenue, Vancouver, British Columbia, Canada. E-mail Cheryl{at}cmmt.ubc.ca
Objective— The purpose of this study was to evaluate the effects of whole body overexpression of human ABCG1 on atherosclerosis in apoE–/– mice.
Methods and Results— We generated BAC transgenic mice in which human ABCG1 is expressed from endogenous regulatory signals, leading to a 3- to 7-fold increase in ABCG1 protein across various tissues. Although the ABCG1 BAC transgene rescued lung lipid accumulation in ABCG1–/– mice, it did not affect plasma lipid levels, macrophage cholesterol efflux to HDL, atherosclerotic lesion area in apoE–/– mice, or levels of tissue cholesterol, cholesterol ester, phospholipids, or triglycerides. Subtle changes in sterol biosynthetic intermediate levels were observed in liver, with chow-fed ABCG1 BAC Tg mice showing a nonsignificant trend toward decreased levels of lathosterol, lanosterol, and desmosterol, and fat-fed mice exhibiting significantly elevated levels of each intermediate. These changes were insufficient to alter ABCA1 expression in liver.
Conclusions— Transgenic human ABCG1 does not influence atherosclerosis in apoE–/– mice but may participate in the regulation of tissue cholesterol biosynthesis.
We developed transgenic mice expressing functional human ABCG1. Elevated ABCG1 levels did not affect plasma lipids, macrophage cholesterol efflux, atherosclerotic lesion area in apoE–/– mice, or levels of tissue cholesterol, cholesterol ester, phospholipids, or triglycerides. Transgenic ABCG1 was, however, associated with altered sterol intermediate levels in liver.
Key Words: ABCG1 cholesterol atherosclerosis cholesterol intermediate
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