Immunohistochemical analysis of Mallory bodies in Wilsonian and non-Wilsonian hepatic copper toxicosis.
Patients with Wilson's disease (WD), Indian childhood cirrhosis (ICC), and idiopathic copper toxicosis (ICT) develop severe liver disease morphologically characterized by ballooning of hepatocytes, inflammation, cytoskeletal alterations, and Mallory body (MB) formation, finally leading to mostly micronodular cirrhosis. The pathogenesis of MBs in copper toxicosis is still unresolved. Immunohistochemical analysis of MBs in different types of copper intoxication revealed that keratin, p62, and ubiquitin are integral components. Thus MBs associated with copper intoxication resemble those present in alcoholic steatohepatitis (ASH) and nonalcoholic steatohepatitis (NASH). p62 is a multifunctional immediate early gene product that, on the one hand, is involved in stress-induced cell signaling (particularly that of oxidative stress) by acting as an adapter protein linking receptor-interacting protein (RIP) with the atypical protein kinase C. On the other hand, p62 binds with high affinity to polyubiquitin and ubiquitinated proteins. In conclusion, p62 accumulation in WD, ICC, and ICT and deposition in MBs indicates a central role of protein misfolding induced by oxidative stress in copper-induced liver toxicity. By sequestering potentially harmful misfolded ubiquitinated proteins as inert cytoplasmic inclusion bodies (e.g., as MBs), p62 may be a major player in an important cellular rescue mechanism in oxidative hepatocyte injury.
Müller
Thomas
T
Department of Pediatrics, University of Innsbruck, Innsbruck, Austria.
Langner
Cord
C
Fuchsbichler
Andrea
A
Heinz-Erian
Peter
P
Ellemunter
Helmut
H
Schlenck
Barbara
B
Bavdekar
Ashish R
AR
Pradhan
Avinash M
AM
Pandit
Anand
A
Müller-Höcker
Josef
J
Melter
Michael
M
Kobayashi
Kunihiko
K
Nagasaka
Hironori
H
Kikuta
Hideaki
H
Müller
Wilfried
W
Tanner
M Stuart
MS
Sternlieb
Irmin
I
Zatloukal
Kurt
K
Denk
Helmut
H
D000293:Adolescent; D000328:Adult; D002648:Child; D002675:Child, Preschool; D003300:Copper / Q000378:metabolism; D005260:Female; D006527:Hepatolenticular Degeneration / Q000378:metabolism / Q000473:pathology*; D006801:Humans; D007150:Immunohistochemistry; D002479:Inclusion Bodies / Q000473:pathology; D007223:Infant; D008099:Liver / Q000378:metabolism / Q000473:pathology*; D008103:Liver Cirrhosis / Q000378:metabolism / Q000473:pathology; D008297:Male; D009410:Nerve Degeneration / Q000378:metabolism / Q000473:pathology
D003300:Copper