microRNA-21靶向调控Spry1介导高糖促进树突状细胞分化、成熟的机制研究

Inflamation and immune response are regarded as the most important pathological physiological mechanism of atherosclerosis formation in diabetes patients. Dendritic cells (DC), as the most potent professional antigen presenting cells, play an important role in this process. Hyperglycaemia is the hallmark of diabetes and is a major independent risk factor for diabetic macrovascular disease. Recent studies suggested that high glucose could promote atherosclerosis through the immune response induced by DCs. But the mechanism remains unclear. miR-21 have been identified to play an important role in differentiation of human monocyte-derived DC. Previous work of our group showed that high glucose could upregulate miR-21 in DC. In this study, the functional role of miR-21 in atherosclerotic physiological process and inflammatory effect was observed in vitro by chemically modified DC with miR-21 mimics and inhibitor. After treated by high glucose, flow cytometry analysis was used to investigate immunophenotypic protein expression on DC and supernatant cytokine measurements were used for immune function assays. Spry1, a potent inhibitor of the Ras/MEK/ERKpathway was identified as a target gene of miR-21. Firefly luciferase activity was determined using the dual luciferase reporter assay system to confirm the target gene．In vivo, we use Apo E-/-;db/db diabetes atherosclerosis mice model to confirm the role of miR-21 in the formation of atherosclerosis. The present study will be expected to provide the novel targets for clinical prevention and treatment of atherosclerosis induced by diabetes mellitus as well as to offer an experimental evidence for establishing effective therapeutic strategies.

炎症和免疫反应近年来被认为是糖尿病（DM）引起动脉粥样硬化（AS）的病理生理基础，树突状细胞（DC）在其中发挥了重要作用。高血糖是DM患者体内最重要和最具特征性的异常，高糖可促进DC的分化、成熟进而参与AS的形成，但其中的机制尚不明确。研究证实miR-21在DC的分化及成熟中具有重要调控作用，我们前期研究发现高糖干预DC后，miR-21的表达明显上调，生物学信息预测Spry1为miR-21的靶基因。基于此，本研究将通过构建高低表达miR-21的DC模型，再用高糖干预，探究miR-21在高糖促进DC分化成熟中的作用及MAPK信号通路变化，并研究miR-21是否通过靶基因Spry1发挥作用；同时利用糖尿病动脉粥样硬化小鼠模型，在体观察miR-21对AS斑块形成及DC分化、成熟的影响。本研究将从miR-21靶向调控角度，为糖尿病动脉粥样硬化的发病机制及AS防治提供新的方向和靶点。

炎症和免疫反应近年来被认为是糖尿病（DM）引起动脉粥样硬化（AS）的病理生理基础，树突状细胞（DC）在其中发挥了重要作用。高血糖是DM患者体内最重要和最具特征性的异常，高糖可促进DC的分化、成熟进而参与AS的形成，但其中的机制尚不明确。我们研究发现高糖干预DC后，miR-144和miR-21的表达明显上调，基于此，本研究通过构建高低表达miR-144和miR-21的DC模型，并用高糖干预，证实了miR-144在高糖促进DC分化成熟中的作用及MAPK信号通路变化；用萤光素酶基因检测及基因沉默方法明确miR-144对CAMKK2的调控作用，并进一步证明mir-144是通过降解CaMKK2的蛋白水平从而调控MAPK通路。本研究将从miR-144靶向调控角度，为糖尿病动脉粥样硬化的发病机制及AS防治提供新的方向和靶点。