基于MCP-1/CCR2轴探讨大黄联合UC-MSCs移植治疗重症急性胰腺炎的机制研究

Severe acute panereatitis (SAP) is a clinical acute abdomen,The mortality rate of SAP is about10%-30%, and the prognosis is unfevorable. Traditional chinese medicine consider SAP as “abdominal pain” “thoracic stagnation” “Yang Ming Fu-Organ Syndrome”. So far, inhibition of pancreatic exocrine, prophylactic antibiotic and nutrition supports are predominat therapy principals for SAP. Rhubarb play in the adjuvant treatment of SAP. Umbilical cord mesenchymal stem cells (UC‑MSCs) have been suggested as a candidate for SAP clinical applications, however, there are major limitations include the lack of organ‑specific accumulation and low survival rates of transplanted cells. In the present study, it was hypothesized that the rhubarb may enhance stem cell‑based tissue repair and regeneration by promoting the specific homing of UC-MSCs and the overall ability to drive them to the damaged area by MCP‑1/CCR2 axes. Therapeutic effects of Rhubarb combined with UC-MSCs transplantation on severe acute pancreatitis was analyzed using RNAi and confocal laser scanning microscope techniques. Subsequently, UC‑MSC were labeled with PKH26 and analyze migration，planting and differentiation. The expression levels of CCR2 were determined in the UC‑MSCs using RT-PCR and flow cytometry. The results of the present study may develop new protocols for the improvement of SAP therapy.

重症急性胰腺炎发病凶险，预后差，病死率高达10%-30%，属中医“腹痛”、“结胸”、“阳明腑实证”等范畴，运用中药大黄治疗有一定功效。脐带间充质干细胞移植可以减轻胰腺炎病情，改善预后，但仍然存在移植细胞存活率低、缺乏靶向性等问题。本课题拟通过中西医结合的手段，研究中药大黄联合脐带间充质干细胞移植治疗重症急性胰腺炎的疗效以及大黄对脐带间充质干细胞迁移及CCR2受体表达的影响，通过RNA干扰、Transwell细胞迁移以及激光共聚焦等方法，阐明MCP-1/CCR2通路在促进脐带间充质干细胞迁移以及治疗重症急性胰腺炎中的作用。本课题的完成有望提高脐带间充质干细胞移植效率和疗效，加速其在重症急性胰腺炎中的临床应用。同时在研究过程中，亦可对大黄改善损伤组织微环境，促进脐带间充质干细胞迁移与分化有新的发现，对于阐释大黄联合脐带间充质干细胞治疗重症急性胰腺炎的作用机理也具有十分重要的理论和临床意义。

间充质干细胞的增殖，迁移和分化能力是影响干细胞治疗效果的重要因素。本课题前期发现通过大黄预处理MSCs可以提高MSCs细胞表面的CCR2受体的表达，通过大鼠体内试验发现，MSCs的迁移能力与对照组相比却没有显著性提高，因此，我们推断，还有其他重要因素和途径控制着MSCs细胞的迁移。现有的研究重点集中在控制间充质干细胞迁移的分子信号通路，然而随着表观遗传学的发展，有多项研究证实间充质干细胞的重要细胞功能包括生长，分化等都受到表观遗传的调控。通过前期的学习，本人利用RNA干扰表观遗传调控基因后，进行细胞迁移能力的筛选，RNA-seq和Chip-qPCR等试验，进而发现JMJD6组蛋白去甲基化酶可以通过调控PDE1C基因结合的组蛋白H4R3me2a的甲基化程度，影响细胞cGMP，5'GMP，cAMP和5'AMP的水平，从而控制间充质干细胞的迁移和细胞动力学特性。本研究的发现，可以更好的调控间充质干细胞的迁移能力和细胞活性，从而提高间充质干细胞治疗的疗效。