携带miRNA的间充质干细胞来源外泌体治疗脓毒症心衰的研究

Sepsis induced cardiac dysfunction(SICD) remains a major cause of morbidity and mortality in the patient suffered from severe trauma despite appropriate resuscitative and antimicrobial approaches. Mesenchymal stem cells (MSCs) have been shown to elicit cardio-protective effects in sepsis. Studies have shown that MSCs can effectively improve the prognosis of sepsis by paracrine large amounts of microvesicles carrying miRNAs by repairing the injured host tissues but the underlying mechanism remains obscure. Researches showed that miRNA play important roles in cell proliferation, apoptosis, inflammation, lipid metabolism and immune response, which are associated with sepsis induced cardiac dysfunction relevant pathophysiological processes. We hypothesized that there are a class of miRNAs involve in various key regulations of SICD and MSC shed lights on the therapy of sepsis via regulation of these miRNAs. In the previous study, we used the microarray to screen out the sepsis related specific circulating miRNA expression profiles, and then validated it in a second cohort. In this project, we selected miR-320a from the previous data. Firstly, measured its effects on apoptosis, proliferation and other biological functions in cardiomyocytes. Secondly, a classic animal model of sepsis was employed in in vivo study of the overall effects of miR-320a. Thirdly, bioinformatics methods and classical molecular biology methods were adopted to predict and identify the upstream and downstream molecular signaling targets of miR-320a. Fourthly, to verifying whether miR-320a-TUD (silencing miR-320a ) have the anti-inflammatory effect in CLP induced septic mouse models, MSC generating exosomes containing a large number of therapeutic miRNAs(miR-320a-TUD), as a carrier to deliver these miRNAs to the injured site to enhance the therapeutic efficiency of BMSCs.

严重脓毒血症目前仍是重症监护室（ICU）非冠脉原因死亡的首要原因，脓毒症心衰病死率可达70%以上且尚缺有效治疗方法。前期研究表明MSC能通过释放大量携miRNA的微囊泡，作用于受损组织,有效改善脓毒症预后,但机制尚不明确。miRNA在细胞增殖、凋亡、炎症、脂质代谢和免疫应答等多种与脓毒症心衰相关的病理生理过程中发挥重要作用。我们推测MSC是通过分泌一类miRNAs治疗脓毒症心衰。前期我们采用芯片技术筛选出脓毒症心衰相关的miRNA, 并已验证。本项目中，我们将从多角度研究筛选出的miR-320a 对心肌细胞生物学效应的影响；并在经典的脓毒症动物模型中研究 miR-320a 的体内整体效应；通过生信预测和经典分生方法预测并确定 miR-320a 的上下游信号通路;并尝试通过转染携带报告基因的miR-320a到MSC，产生含大量治疗性外泌体，并回输至脓毒症小鼠体内，提高干细胞治疗效率。

严重脓毒血症目前仍是重症监护室（ICU）非冠脉原因死亡的首要原因，脓毒症心衰病死率可达70%以上且尚缺有效治疗方法。前期研究表明MSC能通过释放大量携miRNA的微囊泡，作用于受损组织,有效改善脓毒症预后,但机制尚不明确。miRNA在细胞增殖、凋亡、炎症、脂质代谢和免疫应答等多种与脓毒症心衰相关的病理生理过程中发挥重要作用。我们证明了MSC是通过分泌一类miRNAs治疗脓毒症心衰。前期我们采用芯片技术筛选出脓毒症心衰相关的miRNA,并已验证。本项目中，我们从多个角度研究筛选出的miR-320a 对脓毒症心肌细胞生物学效应的影响；并在经典的脓毒症动物模型中研究了 miR-320a 的体内整体效应；通过生信预测和经典分生方法预测并确定 miR-320a 的上下游信号通路;并尝试通过转染携带报告基因的miR-320a到MSC，产生含大量治疗性外泌体，并回输至脓毒症小鼠体内，提高干细胞治疗效率。