【作者】 张江；

【导师】 张建军；

【作者基本信息】 上海交通大学 ， 外科学（普外科）， 2016， 硕士

【摘要】 肝脏缺血再灌注损伤(ischemia-reperfusion injury,IRI)是肝移植尤其心脏死亡(DCD)供肝移植中导致供体、受体损伤的重要临床问题。T细胞免疫激活及枯否细胞浸润及炎性介质释放是公认的主要机制。在之前的研究中,我们发现HIF-2α敲除可以使外周NKT细胞表面的Fas配体表达上调,促使NKT细胞向缺血的肾脏浸润并加重肾脏缺血再灌注损伤。说明HIF-2α在肾IRI中起到重要作用。我们推测HIF-2α的表达在肝脏IRI中同样发挥重要作用。我们采用Lck-Cre转基因小鼠来干扰T细胞和NKT细胞中的HIF-2α基因,并对小鼠构建肝脏缺血再灌注模型实验,观察HIF-2α敲除小鼠的肝脏IRI损伤程度。我们发现HIF-2α敲除同样加重了肝脏缺血再灌注损伤。然而,有趣的是,与脾脏中NKT细胞FasL活化不同,肝脏中NKT细胞的FasL未见明显活化。通过进一步的研究,我们发现敲除组与未敲除组中肝脏调节性T细胞的数量和功能具有明显差异。未敲除组小鼠使用腺苷受体A2A激动剂CGS21680预处理后,肝IRI明显减轻,然而,CGS21680预处理不能减轻敲除组小鼠的IRI。野生型小鼠的肝脏调节性T细胞提取后,经CGS21680处理,肝脏调节性T细胞比例增加。并且,Ras-MAP激酶通路在Hif-2α/ARA调控调节性T细胞功能上具有重要作用。总之,我们的结果不仅再次验证了之前的实验结果并且进一步揭示了HIF-2α在不同器官的作用机制的差异。更多还原

【Abstract】 Hepatic ischemia-reperfusion injury(ischemia-reperfusion injury,IRI)is a important clinical problem in liver transplantation,especially for donates from cardiac death(DCD),T cell immunity and Kupffer cell infiltration and release of inflammatory mediators are recognized as the primary mechanisms.In our previous studies,we found that HIF-2α knockout Fas ligand allows the outer circumferential surface of NKT cells upregulated can induce NKT cells to the ischemic kidney infiltration and aggravate renal ischemia-reperfusion injury.And HIF-2α play an important role in the inflammatory response.We hypothesized that the expression of HIF-2α also plays a role in the liver IRI.We used Lck-Cre transgenic mice to interfere HIF-2α gene in T cells and NKT cells,the mice were then performed with hepatic ischemia-reperfusion experiments.We found that HIF-2α knockout also increased hepatic ischemia-reperfusion injury.However,it is interesting that unlike spleen NKT cells’ Fasl activation,the liver NKT cells FasL showed no significant activation.Through further research,we found that the number and function of regulatory T cells in the liver have a significant difference between knockout and unkonocked groups.Also,in unknockout group mice with the A2 A adenosine receptor agonist CGS21680 pretreatment befor liver IRI can find significantly reduced injury;however,CGS21680 pretreatment faired to reduce IRI of mice in knockout group.So Hif-2αis a vital factor determinating whether CGS21680 can function.After the liver regulatory T cells in wild-type mice extracted,first by CGS21680 treatment increased the proportion of cells in the liver regulatory T.And,Ras-MAP kinase pathway in Hif-2α / ARA on regulatory T cells plays an important role in regulating the function.In conclusion,our results not only once again proven results before and further revealed HIF-2α difference in mechanism of action of different organs.更多还原