Alcohol-associated liver disease: Epidemiology and management

Delineating the heterogeneity of senescence-induced-functional alterations in hepatocytes

BACKGROUND AND AIM

Cellular senescence of hepatocytes involves permanent cell cycle arrest, disrupted cellular bioenergetics, resistance to cell death, and the release of pro-inflammatory cytokines. This 'zombie-like' state perpetuates harmful effects on tissues and holds potential implications for liver disease progression. Remarkably, senescence exhibits heterogeneity, stemming from two crucial factors: the inducing stressor and the cell type. As such, our present study endeavors to characterize stressor-specific changes in senescence phenotype, its related molecular patterns, and cellular bioenergetics in primary mouse hepatocytes (PMH) and hepatocyte-derived liver organoids (HepOrgs).

METHODS

PMH, isolated by collagenase-perfused mouse liver (C57B6/J; 18-23 weeks), were cultured overnight in William's E-medium supplemented with 2% FBS, L-glutamine, and hepatocyte growth supplements. HepOrgs were developed by culturing cells in a 3D matrix for two weeks. The senescence was induced by DNA damage (doxorubicin, cisplatin, and etoposide), oxidative stress (H2O2, and ethanol), and telomere inhibition (BIBR-1532), p53 activation (nutlin-3a), DNA methyl transferase inhibition (5-azacitidine), and metabolism inhibitors (galactosamine and hydroxyurea). SA-β galactosidase activity, immunofluorescence, immunoblotting, and senescence-associated secretory phenotype (SASP), and cellular bioenergetics were used to assess the senescence phenotype.

RESULTS

Each senescence inducer triggers a unique combination of senescence markers in hepatocytes. All senescence inducers, except hydroxyurea and ethanol, increased SA-β galactosidase activity, the most commonly used marker for cellular senescence. Among the SASP factors, CCL2 and IL-10 were consistently upregulated, while Plasminogen activator inhibitor-1 exhibited global downregulation across all modes of senescence. Notably, DNA damage response was activated by DNA damage inducers. Cell cycle markers were most significantly reduced by doxorubicin, cisplatin, and galactosamine. Additionally, DNA damage-induced senescence shifted cellular bioenergetics capacity from glycolysis to oxidative phosphorylation. In HepOrgs exposed to senescence inducers, there was a notable increase in γH2A.X, p53, and p21 levels. Interestingly, while showing a similar trend, SASP gene expression in HepOrgs was significantly higher compared to PMH, demonstrating a several-fold increase.

CONCLUSION

In our study, we demonstrated that each senescence inducer activates a unique combination of senescence markers in PMH. Doxorubicin demonstrated the highest efficacy in inducing senescence, followed by cisplatin and H2O2, with no impact on apoptosis. Each inducer prompted DNA damage response and mitochondrial dysfunction, independent of MAPK/AKT.

Safety and compliance of long-term low-dose ondansetron in alcohol use disorder treatment

BACKGROUND

The increasing prevalence of alcohol use disorder (AUD) and the parallel surge in alcohol-associated liver disease (ALD) emphasize the urgent need for comprehensive alcohol management strategies. Low-dose ondansetron (AD04, a 5-HT3 antagonist) was shown recently to be a promising treatment for AUD with a specific genotypic profile (5-marker). The liver safety of AD04 has never been evaluated in subjects with AUD. The aim of the present study was to assess the liver safety profile of AD04 compared with placebo in subjects with AUD.

METHODS

Liver biochemical parameters were assessed in subjects with AUD with a 5-marker genetic profile who participated in a Phase 3 randomized controlled trial and received either twice-daily, low-dose AD04 (ondansetron 0.33 mg twice daily) or matching placebo, combined with brief psychosocial counseling. ALT, AST, GGT, Serum Bilirubin, MCV, and Prothrombin were evaluated at weeks 0, 12, and 24. Adverse cardiac events, general well-being, and study completion were also assessed.

RESULTS

Low-dose AD04 did not significantly change biochemical markers of liver injury, such as ALT, AST, and Serum Bilirubin. While patients with AUD displayed elevated GGT levels, typically associated with increased alcohol consumption, this parameter remained unaffected by low-dose AD04. Notably, no significant adverse effects were observed due to oral low-dose AD04 treatment.

CONCLUSIONS

Low-dose AD04 has the potential to be a safe treatment option for subjects with AUD and ALD, indicating the need for an RCT for this specific cohort. Such a trial would pave the way for the design of a precision treatment for combined AUD with ALD.

A public health perspective on mitigating the global burden of chronic liver disease

Chronic liver disease is a significant global health problem. Epidemiological trends do not show improvement in chronic liver disease incidence but rather a shift in etiologies, with steatotic liver disease (SLD) from metabolic dysfunction and alcohol becoming increasingly important causes. Consequently, there is a pressing need to develop a comprehensive public health approach for SLD. To that end, we propose a public health framework for preventing and controlling SLD. The framework is anchored on evidence linking physical inactivity, unhealthy dietary patterns, alcohol use, and obesity with both incidence and progression of SLD. Guided by the framework, we review examples of federal/state-level, community-level, and individual-level interventions with the potential to address these determinants of SLD. Ultimately, mitigating SLD's burden requires primary risk factor reduction at multiple socioecological levels, by scaling up the World Health Organization's "best buys," in addition to developing and implementing SLD-specific control interventions.