妊娠晚期合并重症急性胰腺炎时胎盘损伤机制及对胎鼠的影响

Severe acute pancreatitis (SAP) is a serious complication in pregnancy which leading to fetal disress or even death in uterus frequently.In our early experiments of SAP rats in the third trimester model, server damage of placenta in rats were discovered and the macrophage migration inhibitory factor (MIF) in both serum and placenta were highly expressed, significantly. The important roles of MIF induced MAPKs singaling pathways in the progress of SAP and complication were verified by other researches. In order to fully understand the function and mechanism of MIF in placental injury of pregnance with SAP, and the consequent influence on rat fetus. the following experiments were plotted:1)to investigate the expressions of MIF and MAPKs(P38/JNK/ ERK)in placenta of pregnance with SAP rat models, and apply MIF inhibitors to observe changes of downstream MAPKs pathways;2)use siRNA to down-regulate MIF expression in placental trophoblastic cell in vitro, clarify the involvment of MIF in regulating MAPKs pathways and activation to downstream pathway of NF-kB and AP-1 in placental injury. 3) Detect fetal mouse liver, lung, kidney pathological and ultrastructural changes and inflammatory mediator expression in umbilical cord serum, discuss the influences of damage on placenta fetal rats.This study aimed to clarify the mchanism of MIF in placenta injury at severe acute pancreatitis in the third trimester and the effects of placental injury to fetal rats.

妊娠合并重症急性胰腺炎(SAP)是严重的妊娠合并症，常引发胎儿宫内窘迫甚至胎死宫内的严重后果。本课题组前期实验发现在妊娠晚期大鼠合并SAP时血清和胎盘巨噬细胞移动抑制因子(MIF)呈现特异性高表达，且胎盘出现严重损伤。已有研究证实MIF介导的MAPKs信号通路在非妊娠SAP发病过程中起关键作用。因此拟开展以下研究：1）研究妊娠晚期合并SAP大鼠模型中，MIF及MAPKs(P38/JNK/ERK)胎盘表达情况，并通过使用MIF抑制剂观察其对MAPKs通路的影响；2）应用MIF siRNA、抑制剂下调体外培养胎盘滋养细胞MIF表达，阐明MIF在胎盘损伤中参与调控MAPKs通路并激活下游NF-kB、AP-1通路；3）通过检测胎鼠肝、肺、肾脏病理和超微结构变化和脐血中炎症介质表达情况探讨胎盘损伤对胎鼠的影响。通过上述研究旨在阐明MIF在妊娠合并SAP胎盘损伤中的作用机制及胎盘损伤对胎鼠的影响。

妊娠期急性胰腺炎（APIP）是一种不常见的疾病，好发于妊娠晚期，其病情凶险，严重威胁母婴生命安全，但其具体机制尚未完全阐明。胎盘是母体与胎儿之间交换营养物质和代谢产物的重要器官，对胎儿的存活有决定性的作用，胎盘在妊娠期急性胰腺炎中受损可能是导致较高胎儿死亡率的原因之一。巨噬细胞移动抑制因子（MIF）是一种多功能细胞因子，能阻止单核/巨噬细胞的迁移，它还可以通过激活丝裂原激活蛋白激酶，参与多种急性炎症性疾病的发生发展。本课题组结合既往研究，采用胰胆管逆行注射5%牛磺胆酸钠的方式成功建立妊娠晚期合并急性坏死性胰腺（ANPIP）胎盘损伤模型，并采用MIF拮抗剂ISO-1、JNK抑制剂SP600125、p38MAPK抑制剂SB203580进行干预处理，利用血清生化、免疫组化、免疫荧光、TUNEL、ELISA、Western Blot等技术，观察并评估了ANPIP大鼠胰腺、胎盘以及胎鼠肝肾肺的病理改变，超微结构变化，检测MIF和MAPK信号通路的相关蛋白表达水平，了解MIF与MAPK信号通路的相互作用关系。结果证实，阻断MIF可以通过抑制p38MAPK和JNK信号通路的激活，下调胎盘组织和胎鼠肝肾肺中凋亡相关蛋白和炎症相关蛋白的表达水平，减少胎盘和胎鼠肝肾肺的炎症浸润和细胞凋亡，改善胎盘和胎鼠肝肾肺的病理损伤。而且，ISO-1对JNK和p38MAPK的抑制作用与后两者的特异性抑制剂的作用类似。细胞层面，通过应用重组人MIF干预刺激BeWo细胞，模拟ANPIP胎盘损伤，并采用ISO-1、SB203580、SP600125进行干预处理，通过免疫荧光、Western Blot、流式细胞术等方法，对比三种抑制剂的干预效果，进一步证实了MIF/MAPK信号通路在滋养细胞炎症反应和细胞凋亡过程中的作用，为APIP的临床防治和改善APIP母婴的预后提供理论依据和可能的干预靶点。