Liver cell death and anemia in Wilson disease involve acid sphingomyelinase and ceramide.
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.
Lang
Philipp A
PA
Institute of Physiology University of Tübingen, 72076 Tübingen, Germany.
Schenck
Marcus
M
Nicolay
Jan P
JP
Becker
Jan Ulrich
JU
Kempe
Daniela S
DS
Lupescu
Adrian
A
Koka
Saisudha
S
Eisele
Kerstin
K
Klarl
Barbara A
BA
Rübben
Herbert
H
Schmid
Kurt W
KW
Mann
Klaus
K
Hildenbrand
Sibylle
S
Hefter
Harald
H
Huber
Stephan M
SM
Wieder
Thomas
T
Erhardt
Andreas
A
Häussinger
Dieter
D
Gulbins
Erich
E
Lang
Florian
F
D000251:Adenosine Triphosphatases / Q000378:metabolism*; D000328:Adult; D000740:Anemia / Q000209:etiology / Q000378:metabolism*; D000818:Animals; D017209:Apoptosis / Q000187:drug effects*; D027682:Cation Transport Proteins / Q000378:metabolism*; D002518:Ceramides / Q000378:metabolism*; D003300:Copper / Q000633:toxicity*; D000073840:Copper-Transporting ATPases; D004912:Erythrocytes / Q000378:metabolism; D005434:Flow Cytometry; D022781:Hepatocytes / Q000187:drug effects; D006527:Hepatolenticular Degeneration / Q000150:complications / Q000378:metabolism*; D006801:Humans; D020287:In Situ Nick-End Labeling; D008103:Liver Cirrhosis / Q000209:etiology / Q000378:metabolism*; D008875:Middle Aged; D010718:Phosphatidylserines / Q000378:metabolism; D051381:Rats; D013108:Sphingomyelin Phosphodiesterase / Q000097:blood / Q000378:metabolism*
D027682:Cation Transport Proteins; D002518:Ceramides; D010718:Phosphatidylserines; D003300:Copper; D013108:Sphingomyelin Phosphodiesterase; D000251:Adenosine Triphosphatases; D000073840:Copper-Transporting ATPases