Exploring the impact of inflammatory cytokines on alcoholic liver disease: a Mendelian randomization study with bioinformatics insights into potential biological mechanisms.

Background

Alcoholic liver disease (ALD) significantly contributes to global morbidity and mortality. The role of inflammatory cytokines in alcohol-induced liver injury is pivotal yet not fully elucidated.

Objectives

To establish a causal link between inflammatory cytokines and ALD using a Mendelian Randomization (MR) framework.

Methods

This MR study utilized genome-wide significant variants as instrumental variables (IVs) for assessing the relationship between inflammatory cytokines and ALD risk, focusing on individuals of European descent. The approach was supported by comprehensive sensitivity analyses and augmented by bioinformatics tools including differential gene expression, protein-protein interactions (PPI), Gene Ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis, and analysis of immune cell infiltration.

Results

Our findings reveal that increased levels of stem cell growth factor beta (SCGF-β, beta = 0.141, p = .032) and interleukin-7 (IL-7, beta = 0.311, p = .002) are associated with heightened ALD risk, whereas higher levels of macrophage inflammatory protein-1α (MIP-1α, beta = -0.396, p = .004) and basic fibroblast growth factor (bFGF, beta = -0.628, p = .008) are linked to reduced risk. The sensitivity analyses support these robust causal relationships. Bioinformatics analyses around inflammatory cytokine-associated SNP loci suggest multiple pathways through which cytokines influence ALD.

Conclusion

The genetic evidence from this study convincingly demonstrates that certain inflammatory cytokines play directional roles in ALD pathogenesis. These findings provide insights into the complex biological pathways involved and underscore the potential for developing targeted therapies that modulate these inflammatory responses, ultimately improving clinical outcomes for ALD patients.