Physiological and Pathophysiological Implications of Tight Junctions in the Liver

抄録

The liver is the primary organ for processing nutrients, detoxifying xenobiotics, and excreting bile acids. These essential physiological functions are intricately associated with the structural composition of hepatic tissues. Hepatocytes, the main functional cells of the liver, interconnect to form a complex three-dimensional network of hepatic cords that extends from the periphery to the center of the hepatic lobules. Within these hepatic cords, neighboring hepatocytes create intercellular channel-like structures known as bile canaliculi. These canaliculi serve as pathways through which bile acids are secreted and eventually transported into bile ducts. Tight junctions are integral components of cellular structures that act as barriers and regulate the movement of molecules between cells. In the liver, tight junctions play a crucial role in maintaining the structural integrity of the tissue and in regulating the passage of molecules and ions across hepatocytes and other cells. In addition, tight junctions are essential for establishing and maintaining the polarity of hepatocytes. Because of these important roles, the dysfunction of tight junctions is associated with several liver diseases. In this review, the physiological significance of tight junctions in the liver and their implications in hepatic diseases are described.