Changes in mitochondrial DNA and its encoded products in alcoholic cirrhosis

The purpose of this study was to investigate hepatic mitochondrial DNA (mtDNA) damage and changes in its encoded products in patients with alcoholic cirrhosis (AC) in order to understand disease pathogenesis. We enrolled 23 patients with AC, 26 alcoholics without cirrhosis, and 25 normal subjects in this study. Hepatic mtDNA deletions were positioned using a combination of long and accurate polymerase chain reaction (LA PCR) and gene sequencing. The mtDNA copy number was measured using real-time quantitative PCR. The expression of the mtDNA-encoded cytochrome c oxidase 2 (cox2) was detected by western blotting. A large deletion of bases located at positions 749-15486 was identified in hepatic mtDNA from AC patients. Moreover, the mtDNA copy number was significantly reduced (P<0.05), and its encoded product, cox2, was significantly downregulated (P<0.05). Collectively, our results suggest that specific deletions and reduced copy numbers of hepatic mtDNA in patients with AC is an important pathogenetic factor.