The augmenter of liver regeneration induces mitochondrial gene expression in rat liver and enhances oxidative phosphorylation capacity of liver mitochondria.
BACKGROUND
The mammalian augmenter of liver regeneration gene encodes a protein involved in the unique process of liver regeneration. The augmenter of liver regeneration respective protein stimulates hepatocyte proliferation in hepatectomized rats and inhibits cytotoxic activity of liver-derived Natural Killer cells from intact rats. Augmenter of liver regeneration protein shares homology with a Saccharomyces Cerevisiae protein essential for the viability, oxidative phosphorylation and cell-division cycle.


OBJECTIVE
To demonstrate if augmenter of liver regeneration protein, like the homologous in the yeast, plays a role in the regulation of biogenesis of mitochondria.


METHODS
Augmenter of liver regeneration protein was injected in intact rats and, in the hepatic tissue, the expression of two genes located in two different regions of the mitochondrial genome, mitochondrial ATPase 6/8, and ND1 subunit, and of a nuclear gene, mitochondrial Transcription Factor A, were considered. In addition, cytochrome content and oxidative phosphorylation capacity of liver-derived mitochondria were evaluated.


RESULTS
The augmenter of liver regeneration protein administration induces an increase in the mitochondrial gene expression and enhances cytochrome content and oxidative phosphorylation capacity of liver-derived mitochondria.


CONCLUSIONS
The present data demonstrate a comparable role in the regulation of mitochondria biogenesis in the eukaryotic cell like the yeast protein. This phenomenon could be part of the complex mechanism through which augmenter of liver regeneration regulates hepatocyte proliferation.
Polimeno
L
L
Dept of Emergency and Organ Transplantation, University of Bari, Italy.
Capuano
F
F
Marangi
L C
LC
Margiotta
M
M
Lisowsky
T
T
Ierardi
E
E
Francavilla
R
R
Francavilla
A
A
D000251:Adenosine Triphosphatases / Q000096:biosynthesis; D000818:Animals; D004268:DNA-Binding Proteins / Q000096:biosynthesis; D005786:Gene Expression Regulation; D006133:Growth Substances / Q000494:pharmacology*; D008115:Liver Regeneration / Q000502:physiology*; D008297:Male; D008928:Mitochondria / Q000502:physiology*; D024101:Mitochondrial Proteins; D009687:Nuclear Proteins; D010085:Oxidative Phosphorylation; D011506:Proteins; D051381:Rats; D011916:Rats, Inbred F344; D014157:Transcription Factors / Q000096:biosynthesis; D050862:Oxidoreductases Acting on Sulfur Group Donors
D000251:Adenosine Triphosphatases; D004268:DNA-Binding Proteins; D006133:Growth Substances; D024101:Mitochondrial Proteins; D009687:Nuclear Proteins; D011506:Proteins; D014157:Transcription Factors; C489030:Tfam protein, rat; C088825:GFER protein, rat; D050862:Oxidoreductases Acting on Sulfur Group Donors; C422562:mitochondrial transcription factor A