Hepatic ischemia-reperfusion injury (IRI) is observed in liver transplantation and hepato-biliary surgery and is associated with an inflammatory response. Human liver stem cell-derived extracellular vesicles (HLSC-EV) have been demonstrated to reduce liver damage in different experimental settings by accelerating regeneration and by modulating inflammation. The aim of the present study was to investigate whether HLSC-EV may protect liver from IRI in a mouse experimental model. Segmental IRI was obtained by selective clamping of intrahepatic pedicles for 90 min followed by 6 h of reperfusion. HLSC-EV were administered intravenously at the end of the ischemic period and histopathological and biochemical alterations were evaluated in comparison with controls injected with vehicle alone. Intra liver localization of labeled HLSC-EV was assessed by in in vivo Imaging System (IVIS) and the internalization into hepatocytes was confirmed by fluorescence analyses. As compared to the control group, administration of 3 × 10⁹ particles (EV1 group) significantly reduced alanine aminotransferase (ALT) and lactate dehydrogenase (LDH) release, necrosis extension and cytokines expression (TNF-α, CCL-2 and CXCL-10). However, the administration of an increased dose of HLSC-EV (7.5 × 10⁹ particles, EV2 group) showed no significant improvement in respect to controls at enzyme and histology levels, despite a significantly lower cytokine expression. In conclusion, this study demonstrated that 3 × 10⁹ HLSC-EV were able to modulate hepatic IRI by preserving tissue integrity and by reducing transaminases release and inflammatory cytokines expression. By contrast, a higher dose was ineffective suggesting a restricted window of biological activity.

在肝移植和肝胆手术中观察到肝缺血再灌注损伤 (IRI)，并与炎症反应有关。人类肝脏干细胞衍生的细胞外囊泡 (HLSC-EV) 已被证明可以通过加速再生和调节炎症来减少不同实验环境中的肝损伤。本研究的目的是调查 HLSC-EV 是否可以在小鼠实验模型中保护肝脏免受 IRI 的影响。节段性 IRI 是通过选择性夹住肝内蒂 90 分钟，然后再灌注 6 小时获得的。在缺血期结束时静脉内施用 HLSC-EV，并与仅注射载体的对照相比评估组织病理学和生化改变。通过体内成像系统 (IVIS) 评估标记的 HLSC-EV 的肝内定位，并通过荧光分析确认肝细胞内化。与对照组相比，给予 3 × 10⁹颗粒（EV1组）显着降低丙氨酸氨基转移酶（ALT）和乳酸脱氢酶（LDH）的释放、坏死扩展和细胞因子表达（TNF-α、CCL-2和CXCL-10）。然而，尽管细胞因子表达显着降低，但增加剂量的 HLSC-EV（7.5 × 10 ⁹颗粒，EV2 组）的给药在酶和组织学水平上与对照相比没有显着改善。总之，这项研究表明，3 × 10 ⁹ HLSC-EV 能够通过保持组织完整性和减少转氨酶释放和炎性细胞因子表达来调节肝脏 IRI。相比之下，较高的剂量是无效的，表明生物活性的窗口受限。