The Neglected Cousin of the Hepatocyte: How Gallbladder Epithelial Cells Might Contribute to Cholesterol Gallstone Formation

Excerpt

The regulation of biliary cholesterol secretion by hepatocytes has received much interest [1], since it has a major impact on two highly relevant disease complexes, namely, the generation of cholesterol gallstones which have an overall prevalence of 10–20 % in developed countries [2] and reverse cholesterol transport [3], an important protective pathway against atherosclerotic cardiovascular disease as well as the main cause for morbidity and mortality in industrialized societies [4]. Less attention has thus far been given to the potential participation of the gallbladder itself in metabolism, which is somewhat surprising, since the gallbladder has the capacity to actively absorb cholesterol from bile and thereby modulate bile cholesterol content [5]. Changes in transporters mediating this metabolic activity of gallbladder epithelial cells could conceivably contribute to cholesterol gallstone formation in disease. However, only a very limited number of studies exist that have functionally explored the relative contributions of known cholesterol transport proteins to cholesterol transport in and out of the gallbladder (Fig. 1).

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