选择性脂氧合酶基因修饰间充质干细胞负调控SAP-SIRS的机制研究

Systemic inflammatory response syndrome (SIRS) and multiple organ dysfunction caused by severe acute pancreatitis (SAP) are intractable clinical problems. We previously found that lipoxinA4 (LXA4), synthesized by inflammatory cells in the involuting phase of inflammation, can negatively regulate SAP induced SIRS and improve the injured organs. But the mechanism of synthesizing of LXA4 in the early stage of inflammation by non-inflammatory cells remains to be explored. Therefore, it is hypothesized that LXA4 can be synthesized by different lipoxygenase (LO) coding sequences modified mesenchymal stem cells (MSCs), and then SAP will be improved in the early stage of inflammation, with highly level of LXA4, and recruiting to the inflammatory site, to achieve the aim of negatively regulation of SAP-SIRS. Firstly, to explore the conditions how to enhanced synthesize LXA4 through transfecting the 5-LO and/or 15-LO genes into MSCs. Secondly, to verify the modified MSCs whether could achieve the effect of LXA4 as early synthesis, high level, and inflammatory local release. Finally, it’s to confirm that the modified MSCs could negatively regulate SIRS and protect the organ in SAP animal model. The aim of this study is to elucidate the mechanism of synthesizing LXA4 in non-inflammatory cells-MSCs, with enhancing the anti-inflammatory effects, in early phase of inflammation, and targeted treating to inflammation. This study will challenge the obstruction of SAP treatments and provide a new bright way to the negative regulation of SIRS and organ protection.

重症急性胰腺炎（SAP）引发的全身炎症反应综合征（SIRS）及多器官衰竭是困扰临床的难题。我们发现脂氧素A4（LXA4）能负调节SAP诱导的SIRS并保护脏器，但其却由炎症细胞在炎症消退期合成。于炎症早期，由非炎症细胞合成LXA4的机制仍属空白。故提出假设：用不同脂氧合酶（LO）基因编码序列修饰间充质干细胞（MSCs）来合成LXA4，输注此基因修饰细胞使SAP能在炎症早期、高浓度、炎症趋向性地获得干预，达到负调控SIRS的作用。首先，转5-LO和/或15-LO基因于MSCs，探索LXA4合成和增强的条件；验证LO修饰的MSCs可实现LXA4合成的早期性、高水平、趋向释放等效应；于SAP模型证实LO修饰的MSCs能负调控SIRS并保护器官。本研究旨在阐明在非炎症细胞-MSCs合成LXA4使抗炎作用前移、放大、靶向炎症的机制，尝试挑战SAP治疗的重大难点，为SIRS负调控和脏器保护提供新思路。

重症急性胰腺炎（SAP）引发的全身炎症反应综合征（SIRS）及多器官衰竭是困扰临床的难题。我们发现脂氧素A4（LXA4）能负调节SAP诱导的SIRS并保护脏器，但其却由炎症细胞在炎症消退期合成。于炎症早期，由非炎症细胞合成LXA4的机制仍属空白。我们用慢病毒转5-LO和/或15-LO基因于iMSCs，发现iMSCs（5LO+15LO）的组合是LXA4合成和增强的条件；验证LO修饰的MSCs可实现LXA4合成的早期性、高水平、趋向释放等效应；于SAP模型证实LO修饰的MSCs能负调控SIRS并保护肺脏等胰腺外器官。其机制是通过激活PI3K/AKT通路，抑制p38 MAPK的磷酸化，从而抑制下游的NF-κB p65，起到下调炎症的作用；同时激活激活Nrf2/ARE信号转导通路,诱导下游的抗氧化酶HO-1及NQO1的表达，对肺脏等脏器起到保护作用。因此，用不同脂氧合酶（LO）基因编码序列修饰间充质干细胞（MSCs）来合成LXA4，输注此基因修饰细胞使SAP能在炎症早期、高浓度、炎症趋向性地获得干预，达到负调控SIRS的作用。