Alcohol alters hepatic FoxO1, p53, and mitochondrial SIRT5 deacetylation function

Area of Science:

• Hepatology
• Molecular Biology
• Biochemistry

Background:

• Chronic alcohol consumption is known to affect gene expression of SIRT1 and PGC-1alpha.
• FoxO1 and p53 transcription factors are critical for hepatic oxidative stress response and regulated by SIRT1.
• Understanding alcohol's impact on these pathways is crucial for liver health.

Purpose of the Study:

• To investigate if chronic alcohol consumption alters FoxO1 and p53 protein levels and modifications.
• To explore the role of SIRT1 in alcohol-induced changes in these transcription factors.
• To elucidate the impact of alcohol on nuclear-mitochondrial interactions and mitochondrial biogenesis.

Main Methods:

• Rats were fed alcohol-containing liquid diets for 28 days (pair-fed model).
• Hepatic mRNA and protein levels of FoxO1, p53, Akt, SIRT1, SIRT5, and PGC-1alpha were analyzed.
• Post-translational modifications, including phosphorylation and acetylation, were assessed.

Main Results:

• Alcohol increased hepatic mRNA for FoxO1 and p53, but protein levels remained unchanged.
• Phospho-FoxO1 and phospho-Akt levels decreased, while p53 became hyperacetylated.
• Mitochondrial SIRT5 was reduced, and PGC-1alpha was hyperacetylated, indicating disrupted nuclear-mitochondrial communication.

Conclusions:

• Alcohol consumption induces post-translational modifications of FoxO1 and p53, affecting their function.
• Disruption of nuclear-mitochondrial interactions by alcohol contributes to altered mitochondrial biogenesis.
• Reduced SIRT5 and hyperacetylated PGC-1alpha are key mechanisms in alcohol-induced liver damage.