Abstract Body: Background: Metabolic dysfunction-associated steatotic liver disease (MASLD) poses substantial implications for cardiovascular health. With global increases in obesity, MASLD—strongly linked to excess adiposity—has become a leading cause of chronic liver disease. Projections estimate an 18.3% rise in MASLD prevalence by 2030, potentially affecting up to 100 million Americans. Cross-organ communication is increasingly recognised as a determinant of disease progression. Extracellular vesicles (EVs), which shuttle diverse bioactive cargo between cells, are emerging as mediators of inter-organ signalling capable of reprogramming recipient cell gene expression and function.
Hypothesis: Hepatic-derived EVs produced under MASLD conditions carry specific RNA cargo that modulates cardiovascular disease–relevant gene expression programmes and thereby alters human cardiomyocyte phenotype and metabolism.
Aims: To determine whether EVs released from MASLD-modelled liver cells contain distinct RNA species and whether these EVs modify transcriptional, metabolic, and phenotypic characteristics of human cardiomyocytes (hCMs), consistent with a metabolic cardiomyopathy signature.
Methods: Primary human liver cell populations (hepatocytes, hepatic stellate cells, Kupffer cells, and liver sinusoidal endothelial cells) were co-cultured in a three-dimensional liver-on-chip (LOC) platform and exposed to pathophysiological concentrations of fatty acids to recapitulate a MASLD microenvironment. EVs were isolated from conditioned LOC effluents, characterised for size and cargo, and applied to cultured hCMs. hCM responses were evaluated by high-resolution microscopy to assess lipid accumulation and morphology, quantitative PCR, transcriptomics to profile expression of genes controlling fatty acid and glucose metabolism, as well as untargeted metabolomics to quantify changes in key metabolites and lipid species.
Results: EVs derived from MASLD-modelled LOCs induced coordinated changes in hCM gene expression affecting fatty acid oxidation and glucose utilisation pathways, increased intracellular lipid content, and elicited metabolomic shifts indicative of altered substrate handling and energetic stress.
Conclusion: These findings support an EV-mediated liver–heart communication axis in MASLD and implicate hepatic EV RNA cargo in promoting cardiomyocyte metabolic remodelling characteristic of metabolic cardiomyopathy.