Characterization of regulatory mechanisms mediating microRNA selection, packaging and transfer via microvesicles

心血管疾病，如冠心病，是世界范围内的主要死亡原因。其基本病理是动脉粥样硬化。内皮细胞含有内皮细胞，位于血管的最内层。内皮损伤导致内皮功能障碍，炎性细胞向血管壁迁移，形成动脉粥样硬化斑块，最终导致动脉粥样硬化形成。要打破这种最初损伤后的病理信号级联反应，是对内皮修复机制的更好理解，具有重要的治疗意义。初步工作表明，凋亡的内皮细胞释放称为微囊泡(microvesicles，MVS)或凋亡颗粒的小膜泡进入血流。MVS含有多种生物活性介质(RNA、microRNA、蛋白质、细胞因子)，可被转移到靶细胞，影响受体细胞的功能和表型。MIR是一种小的、非编码的RNA，通过与mRNA结合来控制基因的表达，代表着血管止血的关键调节因子。初步研究表明，内皮细胞衍生的MVS(EMVS)可被邻近的内皮细胞和循环中的祖细胞摄取，保护它们免受细胞凋亡的影响，并刺激内皮修复过程。EMV介导的miR-126-3p在受体内皮细胞中的转移和对spred-1的连续抑制可以被认为是EMV介导的内皮再生的基本机制。尽管越来越多的证据表明MVS中的miR在细胞间通讯过程中发挥着关键作用，但目前尚不清楚哪些因素控制着miR在细胞内的选择和包装成EMV。对miR选择、分选和包装成EMVS的细胞内调控机制的分子探索是目前应用的关键。此外，还将表征EMVS转导的miRs在靶细胞中的分子生物学效应。计划中的实验将有助于从机制上更好地理解EMVS的生物发生、分泌、组成以及与靶细胞的相互作用。从长远来看，我们的结果可能会为抗击心血管疾病开辟新的诊断和治疗选择。

Cardiovascular diseases, such as coronary heart disease, are the leading cause of death worldwide. The underlying pathology is atherosclerosis.The endothelium contains of endothelial cells, which are located at the innermost layer of blood vessels. Endothelial injury leads to endothelial dysfunction, the migration of inflammatory cells into the vessel wall, the development of atheroclerotic plaques, and finally to atherogenesis. To break this pathological signaling cascade after an initial injury, is a better understanding of endothelial repair mechanisms of great therapeutic relevance.Preliminary work has shown that apoptotic endothelial cells release small membrane vesicles, called microvesicles (MVs) or apoptotic particles, into the bloodstream. MVs contain a variety of bioactive mediators (RNA, microRNA, proteins, cytokines), which can be transferred into target cells influencing function and phenotype of the recipient cell.Recent studies have shown that the biological function of MVs mainly depends on the intravesicularly microRNA (miR) expression profile. MiRs are small, non-coding RNAs that control gene expression by binding to mRNA and represent key regulators of vascular hemostasis.Preliminary work has shown that endothelial cell-derived MVs (EMVs) are taken up by adjacent endothelial and circulating progenitor cells, protecting them from apoptosis and stimulating endothelial repair processes. The EMV-mediated transfer of miR-126-3p in recipient endothelial cells and the consecutive inhibition of spred-1 could be worked out as an underlying mechanism of EMV-mediated endothelial regeneration.While there is increasing evidence that miRs in MVs play a crucial role in intercellular communication processes, however, it is largely unclear which factors control the intracellular selection and packaging of miRs into EMVs.A molecular exploration of intracellular regulatory mechanisms of miR selection, sorting and packaging into EMVs represents a key point of the present application. Moreover, the molecular biological effect of miRs transferred by EMVs in target cells will be characterized. Finally, the role of MVs as a transfer and application vehicle for selected miRs will be explored.The planned experiments will contribute to a better mechanistic understanding regarding the biogenesis, the secretion, the composition and the interactions with target cells of EMVs. In the long term, our results could open new diagnostic and therapeutic options to combat cardiovascular disease.