IRF-1-Rab27a轴调控的外泌体促进部分肝移植术后肝再生：miR-122/CXCR4双信号远程传递

部分肝移植术(PLTx)供肝的缺血再灌注损伤(IRI)程度和再生能力与预后密切相关，IRI和再生又紧密关联。申请人前期发现转录因子干扰素调节因子1(IRF-1)能与外泌体分泌调控蛋白Rab27a启动子结合，促进其转录和翻译后使外泌体分泌增加，加重IRI；敲低Rab27a抑制外泌体分泌，虽然能减轻IRI，但抑制了PLTx术后肝再生；IRF-1-Rab27a轴调控的外泌体高表达miR-122和CXCR4且能被骨髓来源的肝窦内皮前体细胞(BM-SPC)捕获。本项目拟在前期基础上，用染色质免疫共沉淀、凝胶迁移实验等方法验证生物信息学预测的IRF-1对miR-122和CXCR4转录调控使外泌体高表达此双信号；用外泌体与BM-SPC共培养和PLTx模型探讨该双信号经外泌体远程传递给BM-SPC，促进其增殖、分化并迁移至肝脏，从而增强再生的机制。最终为精准减轻IRI和促进再生，改善PLTx预后提供策略。

Ischemia reperfusion injury (IRI) and regeneration of transplanted liver correlate well with the prognosis in partial liver transplantation (PLTx). They have intimate relationship. Applicants previous research found that the transcription factor interferon regulatory factor 1 (IRF-1) can bind to the promoter of Rab27a which can regulate exosome secretion, promote Rab27a transcription and translation, and then promote exosome secretion. Such exosome can aggravate IRI. Reducing exosome secretion through knocking down Rab27a can alleviate IRI, but inhibit liver regeneration in a mice PLTx model. The IRF-1-Rab27a axis regulated exosome has higher miR-122 and CXCR4 expression and can be captured by bone marrow derived liver sinusoidal epithelial cells (BM-SPC). According to these pre-experimental data, this project will use (1) chromatin immunoprecipitation, electrophoretic mobility shift assay and so on to verify the transcription regulation of miR-122 and CXCR4 by IRF-1, which is predicted by bioinformatics software, leading to the dual signals up-expression in exosome; (2) and use exosome and BM-SPC co-culturing system, as well as mice PLTx model, to explore the molecule mechanisms which miR-122 and CXCR4 dual signals will be remote transferred to BM-SPC by the exosome. The two signals will promote BM-SPC to proliferation, differentiation and be recruited to liver to enhance regeneration. In the end, this project will provide a strategy to improve the prognosis of PLTx through accurately alleviating IRI and enhancing regeneration.