Hanyang Med Rev.  2007 Feb;27(1):20-28.

Transporters and Nuclear Hormone Receptors associated with Cholesterol Metabolism in Gallbladder Epithelial Cells

• Lee J

Abstract

Bile is concentrated in the gallbladder, and is often supersaturated in terms of cholesterol concentration. Such high levels of cholesterol in gallbladder bile has clinical implications with respect to cholesterol gallstone formation. Gallbladder epithelial cells (GBEC) are exposed to high cholesterol concentrations on their apical surface. Therefore, GBEC are uniquely positioned to play an important role in modulating biliary cholesterol concentration. Recently, it has been documented that the key-transporter for polarized cholesterol and phospholipid efflux in GBEC is ATP-binding cassette transporter A1 (ABCA1) and liver X receptor alpha(LXR alpha)/retinoid X receptor (RXR) in the nucleus of GBEC which regulates ABCA1 expression. In addition, it also has been demonstrated that ligands of peroxisome proliferator-activated receptor alpha(PPARalpha) and PPARgamma modulate inflammation and affect ABCA1 expression in GBEC. This evidence proves that GBEC has a perfect system for cholesterol transport. We herein introduce the roles and mechanisms of ABCA1, ABCG5/ABCG8, scavenger receptor class B-I (SR-BI), LXRalpha/RXR, farnesoid X receptor (FXR), and PPARs related to cholesterol transport in GBEC with a review of our study experience and related literature.

Keyword

Gallbladder; Cholesteriol; ABCA1; LXRalpha; PPAR

MeSH Terms

Bile
Cholesterol*
Epithelial Cells*
Gallbladder*
Gallstones
Inflammation
Ligands
Liver
Metabolism*
Peroxisome Proliferator-Activated Receptors
Peroxisomes
PPAR gamma
Receptors, Cytoplasmic and Nuclear*
Receptors, Scavenger
Cholesterol
Ligands
PPAR gamma
Peroxisome Proliferator-Activated Receptors
Receptors, Cytoplasmic and Nuclear
Receptors, Scavenger