Hepatocyte-Derived Exosomes Reduce Hepatic Ischemia-Reperfusion (IR) Injury by Inhibiting Complement Activation.

Abstract

BACKGROUND: Exosomes are specialized secreted vesicles for intercellular communication and signaling pathways as specialized secreted vesicles. Multiple studies have suggested the potential roles of hepatocyte-derived exosomes as biomarkers of liver injury and facilitators of hepatocyte proliferation and liver regeneration. METHODS: By utilizing murine models of hepatic ischemia-reperfusion injury (IRI), we examined the impact of hepatocyte-derived exosomes on mitigating hepatic IRI. RESULTS: Our experiments have demonstrated that significantly lower levels of alanine transaminase, aspartate transaminase, and lactate dehydrogenase in mice treated with hepatocyte-derived exosomes compared with mice treated with phosphate-buffered saline (PBS). Furthermore, hepatocyte-derived exosomes inhibited hepatocyte apoptosis, reduced levels of inflammatory cytokines, and suppressed the entry of inflammatory cells into the liver following hepatic IRI. Complement 3d (C3d) expression showed a notable decrease in exosome-treated mice compared with PBS-treated mice, suggesting that hepatocyte-derived exosomes effectively inhibited complement activation during hepatic IRI. Blocking the fusion of exosomes with cells using Annexin V weakened the protective effects of the exosomes against hepatic IRI. CONCLUSIONS: Our findings highlight the ability of hepatocyte-derived exosomes to mitigate hepatic IRI by inhibiting complement activation. These results reveal a novel role for exosomes in blocking complement activation, suggesting a potential new therapeutic avenue for preventing hepatic IRI.