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

心血管疾病，如冠心病，是全世界死亡的主要原因。其基本病理是动脉粥样硬化。内皮由内皮细胞组成，它们位于血管的最内层。内皮损伤导致内皮功能障碍，炎症细胞向血管壁迁移，形成动脉粥样硬化斑块，最终导致动脉粥样硬化。在初始损伤后打破这种病理信号级联，是更好地理解内皮修复机制的重要治疗意义。初步研究表明，凋亡的内皮细胞释放小的膜囊泡，称为微囊泡（MVs）或凋亡颗粒，进入血液。mv含有多种生物活性介质（RNA、microRNA、蛋白质、细胞因子），这些介质可以转移到靶细胞中，影响受体细胞的功能和表型。最近的研究表明，MVs的生物学功能主要取决于胞内microRNA （miR）的表达谱。MiRs是一种小的非编码rna，通过与mRNA结合来控制基因表达，是血管止血的关键调节因子。初步研究表明，内皮细胞来源的MVs （EMVs）被邻近的内皮细胞和循环祖细胞吸收，保护它们免受凋亡并刺激内皮修复过程。emv介导miR-126-3p在受体内皮细胞中的转移和spred-1的连续抑制可能是emv介导内皮细胞再生的潜在机制。虽然有越来越多的证据表明，MVs中的miRs在细胞间通讯过程中起着至关重要的作用，然而，哪些因素控制了细胞内的选择和miRs包装成emv，这在很大程度上是不清楚的。对miR选择、分类和包装成emv的细胞内调控机制的分子探索是当前应用的一个关键点。此外，emv在靶细胞中转移的miRs的分子生物学效应将被表征。最后，将探讨mv作为特定mir的转移和应用载体的作用。计划中的实验将有助于更好地了解emv的生物发生、分泌、组成及其与靶细胞的相互作用的机制。从长远来看，我们的研究结果可以为对抗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.