Lipid metabolism in the liver.

As a key metabolic organ, the liver is central to the imbalance of high-caloric diets, and particularly dietary fat consumption, in the industrialized countries and their association with the increasing prevalence of morbid obesity. By interacting with the intestinal tract and adipose tissue, the liver plays a key role in various aspects of lipid metabolism. Increasing activation of transcription factors, such as carbohydrate responsive element binding protein (ChREBP), sterol response element binding protein-1c (SREBP-1c), or forkhead box 01 (Fox01), may contribute to fatty acid synthesis. Their translocation occurs via fatty acid transporters such as fatty acid transport proteins (FATP), fatty acid translocase (FAT/CD36), caveolin-1 and fatty acid binding protein (FABP) . Eventually, the accumulation of fat in the form of lipid droplets within the hepatocytes results in hepatic steatosis which, indeed, is a hallmark of liver diseases such as non-alcoholic fatty liver disease, alcoholic fatty liver, acute fatty liver in pregnancy, and hepatitis C. In contrast, lipid accumulation within hepatocytes during liver regeneration is essential. It is thus now becoming clear that steatosis is not only a mere consequence of metabolic imbalance, but that it is also a result of discrete alterations in the beta-oxidation, transport mechanisms, and signaling pathways involved in the synthesis, systemic traffic modalities, and cellular effects of fatty acids. Such a novel insight offers potential options for improved treatment.