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Energy determinants GAPDH and NDPK act as genetic modifiers for hepatocyte inclusion formation.

Snider NT, Weerasinghe SV, Singla A, Leonard JM, Hanada S, Andrews PC, Lok AS, Omary MB - J. Cell Biol. (2011)

Bottom Line: Prominent histological features of some chronic human liver diseases are hepatocyte ballooning and Mallory-Denk bodies.GAPDH knockdown depleted bioenergetic and antioxidant enzymes and elevated hepatocyte ROS, whereas GAPDH overexpression decreased hepatocyte ROS.We propose that GAPDH and NDPK are genetic modifiers of murine DDC-induced liver injury and potentially human liver disease.

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Molecular and Integrative Physiology, University of Michigan, Ann Arbor, MI 48109, USA. nsnider@umich.edu

ABSTRACT
Genetic factors impact liver injury susceptibility and disease progression. Prominent histological features of some chronic human liver diseases are hepatocyte ballooning and Mallory-Denk bodies. In mice, these features are induced by 3,5-diethoxycarbonyl-1,4-dihydrocollidine (DDC) in a strain-dependent manner, with the C57BL and C3H strains showing high and low susceptibility, respectively. To identify modifiers of DDC-induced liver injury, we compared C57BL and C3H mice using proteomic, biochemical, and cell biological tools. DDC elevated reactive oxygen species (ROS) and oxidative stress enzymes preferentially in C57BL livers and isolated hepatocytes. C57BL livers and hepatocytes also manifested significant down-regulation, aggregation, and nuclear translocation of glyceraldehyde 3-phosphate dehydrogenase (GAPDH). GAPDH knockdown depleted bioenergetic and antioxidant enzymes and elevated hepatocyte ROS, whereas GAPDH overexpression decreased hepatocyte ROS. On the other hand, C3H livers had higher expression and activity of the energy-generating nucleoside-diphosphate kinase (NDPK), and knockdown of hepatocyte NDPK augmented DDC-induced ROS formation. Consistent with these findings, cirrhotic, but not normal, human livers contained GAPDH aggregates and NDPK complexes. We propose that GAPDH and NDPK are genetic modifiers of murine DDC-induced liver injury and potentially human liver disease.

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GAPDH and NDPK-B aggregates are present in nuclei-enriched fractions of human alcoholic cirrhosis livers. (A) Cytoplasmic and nuclei-enriched fractions from two different normal human livers (NL) and liver explants of eight patients with alcoholic cirrhosis were analyzed by SDS-PAGE followed by blotting for GAPDH (reducing [R] or nonreducing [NR] conditions). Lamin B1 and β-tubulin were used as loading controls for the nuclear and cytoplasmic fractions, respectively. GAPDH aggregates (denoted by asterisks) are present in the diseased but not the normal human livers. (B) Analysis of NDPK-B expression in total liver lysates (under reducing conditions) from the same samples as in A. Higher molecular weight NDPK-B–containing complexes are present in the diseased but not the normal human livers.
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fig9: GAPDH and NDPK-B aggregates are present in nuclei-enriched fractions of human alcoholic cirrhosis livers. (A) Cytoplasmic and nuclei-enriched fractions from two different normal human livers (NL) and liver explants of eight patients with alcoholic cirrhosis were analyzed by SDS-PAGE followed by blotting for GAPDH (reducing [R] or nonreducing [NR] conditions). Lamin B1 and β-tubulin were used as loading controls for the nuclear and cytoplasmic fractions, respectively. GAPDH aggregates (denoted by asterisks) are present in the diseased but not the normal human livers. (B) Analysis of NDPK-B expression in total liver lysates (under reducing conditions) from the same samples as in A. Higher molecular weight NDPK-B–containing complexes are present in the diseased but not the normal human livers.

Mentions: To examine the potential clinical relevance of our findings, we compared the presence of cytoplasmic and nuclear GAPDH aggregates in livers from alcoholic cirrhosis patients with normal control livers. Notably, the diseased but not normal human livers contained cytoplasmic and nuclear GAPDH aggregates (Fig. 9 A). Although there were no significant differences in monomeric NDPK-B protein between normal and diseased livers, the latter contained significant levels of higher molecular weight NDPK-B–containing species (Fig. 9 B). Future identification of the components of these complexes may yield additional mechanistic insight into a potential role of this enzyme in liver disease. Collectively, our findings in the genetically susceptible mouse model of MDB formation may extrapolate to human ALD with respect to GAPDH and NDPK function.


Energy determinants GAPDH and NDPK act as genetic modifiers for hepatocyte inclusion formation.

Snider NT, Weerasinghe SV, Singla A, Leonard JM, Hanada S, Andrews PC, Lok AS, Omary MB - J. Cell Biol. (2011)

GAPDH and NDPK-B aggregates are present in nuclei-enriched fractions of human alcoholic cirrhosis livers. (A) Cytoplasmic and nuclei-enriched fractions from two different normal human livers (NL) and liver explants of eight patients with alcoholic cirrhosis were analyzed by SDS-PAGE followed by blotting for GAPDH (reducing [R] or nonreducing [NR] conditions). Lamin B1 and β-tubulin were used as loading controls for the nuclear and cytoplasmic fractions, respectively. GAPDH aggregates (denoted by asterisks) are present in the diseased but not the normal human livers. (B) Analysis of NDPK-B expression in total liver lysates (under reducing conditions) from the same samples as in A. Higher molecular weight NDPK-B–containing complexes are present in the diseased but not the normal human livers.
© Copyright Policy - openaccess
Related In: Results  -  Collection

License 1 - License 2
Show All Figures
getmorefigures.php?uid=PMC3198167&req=5

fig9: GAPDH and NDPK-B aggregates are present in nuclei-enriched fractions of human alcoholic cirrhosis livers. (A) Cytoplasmic and nuclei-enriched fractions from two different normal human livers (NL) and liver explants of eight patients with alcoholic cirrhosis were analyzed by SDS-PAGE followed by blotting for GAPDH (reducing [R] or nonreducing [NR] conditions). Lamin B1 and β-tubulin were used as loading controls for the nuclear and cytoplasmic fractions, respectively. GAPDH aggregates (denoted by asterisks) are present in the diseased but not the normal human livers. (B) Analysis of NDPK-B expression in total liver lysates (under reducing conditions) from the same samples as in A. Higher molecular weight NDPK-B–containing complexes are present in the diseased but not the normal human livers.
Mentions: To examine the potential clinical relevance of our findings, we compared the presence of cytoplasmic and nuclear GAPDH aggregates in livers from alcoholic cirrhosis patients with normal control livers. Notably, the diseased but not normal human livers contained cytoplasmic and nuclear GAPDH aggregates (Fig. 9 A). Although there were no significant differences in monomeric NDPK-B protein between normal and diseased livers, the latter contained significant levels of higher molecular weight NDPK-B–containing species (Fig. 9 B). Future identification of the components of these complexes may yield additional mechanistic insight into a potential role of this enzyme in liver disease. Collectively, our findings in the genetically susceptible mouse model of MDB formation may extrapolate to human ALD with respect to GAPDH and NDPK function.

Bottom Line: Prominent histological features of some chronic human liver diseases are hepatocyte ballooning and Mallory-Denk bodies.GAPDH knockdown depleted bioenergetic and antioxidant enzymes and elevated hepatocyte ROS, whereas GAPDH overexpression decreased hepatocyte ROS.We propose that GAPDH and NDPK are genetic modifiers of murine DDC-induced liver injury and potentially human liver disease.

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Molecular and Integrative Physiology, University of Michigan, Ann Arbor, MI 48109, USA. nsnider@umich.edu

ABSTRACT
Genetic factors impact liver injury susceptibility and disease progression. Prominent histological features of some chronic human liver diseases are hepatocyte ballooning and Mallory-Denk bodies. In mice, these features are induced by 3,5-diethoxycarbonyl-1,4-dihydrocollidine (DDC) in a strain-dependent manner, with the C57BL and C3H strains showing high and low susceptibility, respectively. To identify modifiers of DDC-induced liver injury, we compared C57BL and C3H mice using proteomic, biochemical, and cell biological tools. DDC elevated reactive oxygen species (ROS) and oxidative stress enzymes preferentially in C57BL livers and isolated hepatocytes. C57BL livers and hepatocytes also manifested significant down-regulation, aggregation, and nuclear translocation of glyceraldehyde 3-phosphate dehydrogenase (GAPDH). GAPDH knockdown depleted bioenergetic and antioxidant enzymes and elevated hepatocyte ROS, whereas GAPDH overexpression decreased hepatocyte ROS. On the other hand, C3H livers had higher expression and activity of the energy-generating nucleoside-diphosphate kinase (NDPK), and knockdown of hepatocyte NDPK augmented DDC-induced ROS formation. Consistent with these findings, cirrhotic, but not normal, human livers contained GAPDH aggregates and NDPK complexes. We propose that GAPDH and NDPK are genetic modifiers of murine DDC-induced liver injury and potentially human liver disease.

Show MeSH
Related in: MedlinePlus