The keratin cytoskeleton in liver diseases.

The keratin intermediate filament (IF) cytoskeleton of hepatocytes has continuously gained medical relevance over the last two decades. Originally it was mainly recognized as a differentiation marker for diagnostic purposes in pathology. However, keratin IFs were soon identified as major cellular structures to be affected in a variety of chronic liver diseases, such as alcoholic and non-alcoholic steatohepatitis (ASH, NASH), copper toxicosis, and cholestasis. Based on observations in keratin gene knock-out mice, the insight into the functional role of keratins was extended from a mere structural role providing mechanical stability to hepatocytes, to an additional role as target and modulator of toxic stress and apoptosis. The functional relevance of keratins in human diseases has recently been underlined by the identification of mutations in keratin genes in patients with liver cirrhosis.