Pre-apoptotic alterations in hepatocytes of TNFalpha-treated galactosamine-sensitized mice.

TY - JOUR

T1 - Pre-apoptotic alterations in hepatocytes of TNFalpha-treated galactosamine-sensitized mice.

AU - Angermüller, S

AU - Künstle, G

AU - Tiegs, Gisa

PY - 1998

Y1 - 1998

N2 - Tumor necrosis factor (TNF) induces apoptotic death of hepatocytes in the galactosamine (GalN)-sensitized mouse liver after 5 hr. In our study, the most remarkable sign of the early stage of apoptosis was the focal rupture of the outer mitochondrial membrane. Parts of the inner membrane extended through the gap of the outer membrane, whereas the rest of the inner membrane still formed the cristae. This feature appeared in hepatocytes before chromatin condensation. With the diaminobenzidine technique for localization of cytochrome oxidase activity, the reaction product was detectable by light and electron microscopy. Ten percent of the hepatocytes were apoptotic, with condensed chromatin and high enzyme activity, 37% were pre-apoptotic, without chromatin condensation but high enzyme activity, and 53% had neither condensed chromatin nor a remarkable reaction product of cytochrome oxidase activity. Fas (APO-1, CD95) molecules on the plasma membrane of hepatocytes increased and were represented immunohistochemically in cells without chromatin condensation. DNA strand breaks were also detectable before chromatin aggregation. The results of this study indicate that mitochondria play a pivotal role in pre-apoptotic hepatocytes, together with an increase of the Fas molecule on the plasma membrane and with the occurrence of DNA strand breaks in the nucleus.

AB - Tumor necrosis factor (TNF) induces apoptotic death of hepatocytes in the galactosamine (GalN)-sensitized mouse liver after 5 hr. In our study, the most remarkable sign of the early stage of apoptosis was the focal rupture of the outer mitochondrial membrane. Parts of the inner membrane extended through the gap of the outer membrane, whereas the rest of the inner membrane still formed the cristae. This feature appeared in hepatocytes before chromatin condensation. With the diaminobenzidine technique for localization of cytochrome oxidase activity, the reaction product was detectable by light and electron microscopy. Ten percent of the hepatocytes were apoptotic, with condensed chromatin and high enzyme activity, 37% were pre-apoptotic, without chromatin condensation but high enzyme activity, and 53% had neither condensed chromatin nor a remarkable reaction product of cytochrome oxidase activity. Fas (APO-1, CD95) molecules on the plasma membrane of hepatocytes increased and were represented immunohistochemically in cells without chromatin condensation. DNA strand breaks were also detectable before chromatin aggregation. The results of this study indicate that mitochondria play a pivotal role in pre-apoptotic hepatocytes, together with an increase of the Fas molecule on the plasma membrane and with the occurrence of DNA strand breaks in the nucleus.

KW - Animals

KW - Male

KW - Immunohistochemistry

KW - Mice

KW - Mice, Inbred BALB C

KW - Apoptosis

KW - Histocytochemistry

KW - Galactosamine/pharmacology

KW - DNA Fragmentation

KW - Tumor Necrosis Factor-alpha/pharmacology

KW - Antigens, CD95/analysis

KW - Chromatin/pathology

KW - Electron Transport Complex IV/analysis

KW - Liver/chemistry/drug effects/pathology/ultrastructure

KW - Mitochondria/pathology

KW - Animals

KW - Male

KW - Immunohistochemistry

KW - Mice

KW - Mice, Inbred BALB C

KW - Apoptosis

KW - Histocytochemistry

KW - Galactosamine/pharmacology

KW - DNA Fragmentation

KW - Tumor Necrosis Factor-alpha/pharmacology

KW - Antigens, CD95/analysis

KW - Chromatin/pathology

KW - Electron Transport Complex IV/analysis

KW - Liver/chemistry/drug effects/pathology/ultrastructure

KW - Mitochondria/pathology

M3 - SCORING: Journal article

VL - 46

SP - 1175

EP - 1183

JO - J HISTOCHEM CYTOCHEM

JF - J HISTOCHEM CYTOCHEM

SN - 0022-1554

IS - 10

M1 - 10

ER -