Liver cell death and anemia in Wilson disease involve acid sphingomyelinase and ceramide

• Published in: Nature medicine Vol. 13; no. 2; pp. 164 - 170
• Main Authors: Gulbins, Erich, Lang, Florian, Lang, Philipp A, Schenck, Marcus, Nicolay, Jan P, Becker, Jan Ulrich, Kempe, Daniela S, Lupescu, Adrian, Koka, Saisudha, Eisele, Kerstin, Klarl, Barbara A, Rübben, Herbert, Schmid, Kurt W, Mann, Klaus, Hildenbrand, Sibylle, Hefter, Harald, Huber, Stephan M, Wieder, Thomas, Erhardt, Andreas, Häussinger, Dieter
• Format: Journal Article
• Language: English
• Published: United States Nature Publishing Group 01.02.2007
• Subjects: Adenosine Triphosphatases - metabolism; Adult; Anemia; Anemia - etiology; Anemia - metabolism; Animals; Apoptosis; Apoptosis - drug effects; Cation Transport Proteins - metabolism; Cell death; Cellular biology; Ceramides - metabolism; Copper; Copper - toxicity; Copper-transporting ATPases; Erythrocytes - metabolism; Flow Cytometry; Hepatocytes - drug effects; Hepatolenticular Degeneration - complications; Hepatolenticular Degeneration - metabolism; Humans; In Situ Nick-End Labeling; Liver Cirrhosis - etiology; Liver Cirrhosis - metabolism; Liver diseases; Middle Aged; Phosphatidylserines - metabolism; Rats; Rodents; Sphingomyelin Phosphodiesterase - blood; Sphingomyelin Phosphodiesterase - metabolism
• ISSN: 1078-8956; 1546-170X
• DOI: 10.1038/nm1539

Wilson disease is caused by accumulation of Cu(2+) in cells, which results in liver cirrhosis and, occasionally, anemia. Here, we show that Cu(2+) triggers hepatocyte apoptosis through activation of acid sphingomyelinase (Asm) and release of ceramide. Genetic deficiency or pharmacological inhibition of Asm prevented Cu(2+)-induced hepatocyte apoptosis and protected rats, genetically prone to develop Wilson disease, from acute hepatocyte death, liver failure and early death. Cu(2+) induced the secretion of activated Asm from leukocytes, leading to ceramide release in and phosphatidylserine exposure on erythrocytes, events also prevented by inhibition of Asm. Phosphatidylserine exposure resulted in immediate clearance of affected erythrocytes from the blood in mice. Accordingly, individuals with Wilson disease showed elevated plasma levels of Asm, and displayed a constitutive increase of ceramide- and phosphatidylserine-positive erythrocytes. Our data suggest a previously unidentified mechanism for liver cirrhosis and anemia in Wilson disease.