IMPACT OF HEPG2.2.15-DERIVED EXOSOMES ON HEPATIC STELLATE CELL ACTIVATION AND FIBROSIS: IMPLICATIONS FOR LIVER HEALTH IN ATHLETES

Abstract

Objective: This study investigates the influence of HepG2.2.15-derived exosomes on the activation and fibrosis of hepatic stellate cells (LX2), exploring the underlying molecular mechanisms and their potential impact on liver health in athletes. Methods: Exosomes were isolated from HepG2.2.15 (a HepG2 cell line expressing hepatitis B virus), HepG2, and WRL68 cells. The presence of the exosomal marker protein CD9 was confirmed via Western blotting. Oil Red and DiI staining were used to assess activation and uptake of exosomes by LX2 cells, respectively. Cellular proliferation and the expression of fibrosis markers in LX2 cells were analyzed using EDU staining and Western blotting. Small RNA sequencing of the exosomes identified differentially expressed miRNAs (DE-miRNAs), with subsequent gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses performed to elucidate the functional roles and pathways of these miRNAs. Results: Exosomes derived from HepG2.2.15 cells significantly influenced the activation, proliferation, and fibrotic responses in LX2 cells. Notably, 27 miRNAs were differentially expressed in these exosomes. GO analysis highlighted that these DE-miRNAs targeted processes integral to cell differentiation, intracellular signal transduction, and the negative regulation of the apoptotic process, among others. KEGG pathway analysis revealed significant enrichment in pathways related to ubiquitin-mediated proteolysis, MAPK signaling, viral carcinogenesis, and toll-like receptor signaling. Conclusion: The study demonstrates that exosomes from HepG2.2.15 cells promote activation, proliferation, and fibrosis in hepatic stellate cells, potentially mediated by specific miRNAs. These findings suggest a mechanism by which liver health could be compromised, particularly in contexts of viral infection or chronic liver disease. Understanding these pathways provides crucial insights into the management of liver health in athletes, who may be susceptible to liver stress and damage through intense physical activity and metabolic demands. This research supports the development of targeted strategies to maintain liver function and overall health in athletic populations.