Role of Elevated Intracellular S-Adenosylhomocysteine in the Pathogenesis of Alcohol-Related Liver Disease

Background: The earliest manifestation of alcohol-related liver disease (ALD) is steatosis, characterized by the accumulation of lipid droplets (LDs) in hepatocytes. Findings from our laboratory have indicated that many pathological changes, including steatosis, correlate with the alcohol-induced hepatocellular increases in S-adenosylhomocysteine (SAH). Based on these considerations, we hypothesized that an experimental increase in intracellular SAH alone will result in similar steatotic changes to those seen after alcohol exposure. Methods: Freshly isolated rat hepatocytes grown on collagen-coated plates were exposed to serum-free medium containing 50 µmol/L oleic acid and varying concentrations of 3-deazaadenosine (DZA) to experimentally elevate intracellular SAH levels. Results: Overnight exposure to DZA treatment dose-dependently increased hepatocellular triglyceride accumulation, which was also evident by morphological visualization of larger-sized LDs. The rise in triglycerides and LDs accompanied increases in mRNA and protein levels of several LD-associated proteins known to regulate LD number and size. Furthermore, DZA treatment caused a decline in the levels of lipases that prevent fat accumulation as well as increased the expression of factors involved in lipogenesis and fatty acid mobilization. Collectively, our results indicate that the elevation of intracellular SAH is sufficient to promote fat accumulation in hepatocytes, which is similar to that seen after alcohol exposure.

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Mechanisms of chronic alcohol exposure-induced aggressiveness in cellular model of HCC and recovery after alcohol withdrawal

10.21203/rs.3.rs-1030904/v1 ◽

2021 ◽

Author(s):

Constance Marié ◽

Gregory Fouquet ◽

Rabbind Singh Amrathlal ◽

Nicolas Jankovsky ◽

Hicham Bouhlal ◽

...

Keyword(s):

Liver Disease ◽

Cancer Progression ◽

Alcohol Withdrawal ◽

Alcohol Exposure ◽

Epidemiological Studies ◽

Migration And Invasion ◽

Mrna Levels ◽

Chronic Alcohol ◽

Chronic Alcohol Exposure ◽

Related Liver Disease

Abstract Alcohol-related liver disease is the most prevalent chronic liver disease worldwide, accounting for 30% of hepatocellular carcinoma (HCC) cases and HCC-specific deaths. However, the knowledge on mechanisms by which alcohol consumption leads to cancer progression and its aggressiveness is limited. Better understanding of the clinical features and the mechanisms of alcohol-induced HCC are of critical importance for prevention and the development of novel treatments.Early stage Huh-7 and advanced SNU449 liver cancer cell lines were subjected to Chronic Alcohol Exposure (CAE), at different doses for 6 months followed by one-month alcohol withdrawal period. ADH activity and ALDH expression were much lower in SNU449 compared with Huh-7 cells and at the 270mM dose, CAE decreased cell viability by about 50% and 80%, respectively in Huh-7 and SNU449 cells but induced mortality only in Huh-7 cells. Thus, Huh-7 may be more vulnerable to ethanol toxicity because of the higher levels of acetaldehyde. CAE induced a dose-dependent increase in cell migration and invasion and also in the expression of Cancer Stem Cells markers (CD133, CD44, CD90). CAE in Huh-7 cells selectively activated ERK1/2 and inhibited GSK3β signaling pathways. Most of the changes induced by CAE were reversed after alcohol withdrawal. Interestingly we confirmed the increase in CD133 mRNA levels in the tumoral tissue of patients with ethanol-related HCC compared to other HCC etiologies.Our results may explain the benefits observed in epidemiological studies showing a significant increase of overall survival in abstinent compared with non-abstinent patients.

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PCSK9 inhibition as a novel therapeutic target for alcoholic liver disease

Scientific Reports ◽

10.1038/s41598-019-53603-6 ◽

2019 ◽

Vol 9 (1) ◽

Cited By ~ 10

Author(s):

Ji Soo Lee ◽

Partha Mukhopadhyay ◽

Csaba Matyas ◽

Eszter Trojnar ◽

Janos Paloczi ◽

...

Keyword(s):

Monoclonal Antibody ◽

Liver Disease ◽

Mrna Expression ◽

Alcoholic Liver Disease ◽

Rat Model ◽

Control Diet ◽

Alcohol Exposure ◽

Histopathological Analysis ◽

Triglyceride Accumulation ◽

Pcsk9 Inhibition

AbstractAlcoholic liver disease (ALD) causes significant morbidity and mortality, and pharmacological treatment options are limited. In this study, we evaluated the PCSK9 inhibitor alirocumab, a monoclonal antibody that robustly reduces low-density lipoprotein cholesterol (LDL-C), for the treatment of ALD using a rat model of chronic alcohol exposure. Alirocumab (50 mg/kg) or vehicle was administered weekly for 6 weeks to rats receiving a 12% alcohol liquid diet or an isocaloric control diet. At the end of the alcohol exposure protocol, serum and liver samples were obtained for molecular characterization and histopathological analysis. PCSK9 inhibition with alirocumab attenuated alcohol-induced hepatic triglyceride accumulation through regulation of lipid metabolism (mRNA expression of modulators of fatty acid synthesis (FAS) and catabolism (PPARα and CPT1)), hepatocellular injury (ALT), hepatic inflammation (mRNA expression of pro-inflammatory cytokines/chemokines (TNFa, IL-1β, IL-22, IL-33, IL-17α, IL-2, MIP-2, and MCP-1), and neutrophil infiltration (myeloperoxidase staining)). Alirocumab treatment also attenuated alcohol-induced PCSK9 mRNA elevation and upregulated LDL-receptor (LDL-R) via modulation of the transcription factors (SREBP-1, SREBP-2, and E2F1) in liver. We demonstrated that chronic anti-PCSK9 treatment using the monoclonal antibody alirocumab attenuated alcohol-induced steatohepatitis in the rat model. Given the large unmet clinical need for effective and novel treatments for ALD, anti-PCSK9 treatment with the monoclonal antibody that spares liver metabolism is a viable new therapeutic possibility. Future studies are needed to elucidate the exact role of PCSK9 in ALD and alcohol use disorder (AUD) and to evaluate efficacy and safety of anti-PCSK9 treatment in clinical populations with ALD/AUD.

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