RIPK3-MLKL介导的坏死性凋亡促进脂肪肝缺血再灌注损伤（IRI）的作用和机制研究

脂肪肝在肝脏外科和肝移植手术中对缺血再灌注损伤(IRI)更加易感和严重，但其分子机制尚不十分清楚。通过分析脂肪肝及正常肝IR后肝组织中基因表达，发现IR后相较于正常肝，脂肪肝中细胞坏死性凋亡相关标志物(RIPK3和MLKL)表达显著增高。体外缺氧复氧(H/R)实验也证明，相较于正常肝，脂肪肝细胞坏死性凋亡相关指标显著上升。更重要的是，细胞坏死性凋亡抑制剂可显著保护小鼠脂肪肝IRI。鉴于细胞坏死性凋亡是一种促炎的细胞死亡方式，我们提出：脂肪肝IRI易感的机制可能是IRI引起脂肪性肝细胞发生坏死性凋亡，并通过释放大量DAPMs引起过激炎症反应，对肝脏细胞造成二次打击加重IRI。本项目拟从介导细胞坏死性凋亡的关键分子通路入手，结合肝细胞特异性RIPK3敲除小鼠及抑制剂等手段，阐明IRI时脂肪肝细胞发生坏死性凋亡的分子机制，探讨阻断坏死性凋亡减轻脂肪肝IRI的可能性，提出脂肪肝IRI易感的新机制。

Fatty liver is more susceptible and seriously to ischemia-reperfusion injury (IRI) in liver surgery and liver transplantation, but the molecular mechanism is unclear. By analyzing the gene expression in liver tissues of fatty liver and normal liver after IR treatment, it was found that the level of cell necroptosis-related markers (RIPK3 and MLKL) in fatty liver were significantly higher than that in normal liver. In vitro experiments also proved that compared with normal liver, cell necroptosis-related markers were increased significantly in fatty liver after hypoxia and reoxygenation (H/R) treatment. What's more, inhibiting cell necroptosis can significantly protect fatty liver from IRI. In view of the fact that cell necroptosis is a pro-inflammatory cell death mode, we propose that the mechanism of fatty liver susceptible to IRI may be that IRI induces cell necroptosis in fatty liver and causes excessive inflammation by releasing a large amount of DAPMs, and which induces a secondary hit to hepatocytes and aggravates IRI. This project aims to clarify the molecular mechanism of necroptosis in fatty liver cells during IRI through RIPK3 hepatocyte-specific knockout mice and various inhibitors, and explore the possibility to alleviate fatty liver IRI by inhibiting necrptosis, and propose a new mechanism of fatty liver susceptible to IRI.