RRC ID 68799
Author Uto-Kondo H, Ayaori M, Sotherden GM, Nakaya K, Sasaki M, Yogo M, Komatsu T, Takiguchi S, Yakushiji E, Ogura M, Nishida T, Endo Y, Ikewaki K.
Title Ezetimibe enhances macrophage reverse cholesterol transport in hamsters: contribution of hepato-biliary pathway.
Journal Biochim Biophys Acta
Abstract Reverse cholesterol transport (RCT) is pivotal in the return of excess cholesterol from peripheral tissues to the liver for excretion in bile and eventually feces. RCT from macrophages is a critical anti-atherogenicity mechanism of HDL. As the cholesterol absorption inhibitor ezetimibe promoted RCT in mice, which lack cholesterol ester transfer protein (CETP), we investigated its effects in hamsters, which have CETP. A high-cholesterol diet (HC) increased cholesterol levels throughout lipoprotein fractions and ezetimibe markedly reduced VLDL/LDL cholesterol levels under both normal chow (NC) and HC. However, ezetimibe did not affect and reduced HDL-cholesterol levels under NC and HC, respectively. Intraperitoneal injection of (3)H-cholesterol pre-labeled macrophages in an in vivo RCT assay increased tracer accumulation in the liver but reduced it in bile under HC, and these changes were completely cancelled by ezetimibe. Under both NC and HC, ezetimibe reduced tracer levels in the liver but increased them in feces, indicating promotion of RCT in vivo. We performed a RCT assay using hamsters subjected to bile duct ligation (BDL) to clarify whether a transintestinal cholesterol efflux (TICE) pathway contributes to ezetimibe's enhancement of RCT. BDL markedly inhibited macrophage-derived (3)H-cholesterol excretion to feces and cancelled ezetimibe's stimulatory effect on RCT, suggesting that biliary cholesterol excretion is a major contributor in RCT promotion by ezetimibe but the contribution of the TICE pathway is minimal. In conclusions, ezetimibe exerts an additive anti-atherogenic property by enhancing RCT in hamsters. Our findings suggest that this property is independent of the TICE pathway.
Volume 1841(9)
Pages 1247-55
Published 2014-9-1
DOI 10.1016/j.bbalip.2014.05.009
PII S1388-1981(14)00100-0
PMID 24989153
MeSH Animals Anticholesteremic Agents / pharmacology* Azetidines / pharmacology* Bile / drug effects* Bile / metabolism Bile Ducts / surgery Biological Transport / drug effects Cholesterol Ester Transfer Proteins / metabolism Cholesterol, HDL / metabolism* Cholesterol, LDL / metabolism Cholesterol, VLDL / metabolism Cricetinae Diet Ezetimibe Feces / chemistry Liver / drug effects* Liver / metabolism Macrophages / cytology Macrophages / drug effects* Macrophages / metabolism Male Tritium
Resource
Human and Animal Cells J774.1