“核HO-1”调控miRNA-125a-5p影响血脊髓屏障结构和功能的机制研究

项目名称： “核HO-1”调控miRNA-125a-5p影响血脊髓屏障结构和功能的机制研究

项目编号： No.81471853

项目类型： 面上项目

立项/批准年度： 2015

项目学科： 医药、卫生

项目作者： 曹阳

作者单位： 锦州医科大学

项目金额： 72万元

中文摘要： 脊髓损伤是一种严重的中枢神经系统损伤，伴有血脊髓屏障(blood-spinal cord barrier,BSCB)的破坏。研究证实核HO-1可参与基因调控，维持血管内皮细胞正常功能。本课题组将携带HO-1CΔ23（核HO-1)的质粒转染入血管内皮细胞中，证实转染核HO-1的血管内皮细胞，miRNA-125a-5p表达显著上调，且显著降低缺氧或ROS诱导的BSCB的通透性。因此，我们推测核HO-1是调控BSCB通透性的重要靶点。本项目首先研究核HO-1对BSCB结构和功能的影响；进一步研究miRNA-125a-5p在核HO-1调节BSCB中的作用和机制；最后研究外源性给予表达核HO-1的重组腺病毒，对脊髓损伤后BSCB通透性和神经功能的影响。本项目首次揭示了核HO-1改善脊髓损伤后BSCB的功能和调控机制，丰富了脊髓损伤修复理论，为脊髓损伤的治疗开创新靶点。

中文关键词： 脊髓损伤；血管内皮细胞；血管反应性；血脊髓屏障；核血红素氧合酶1

英文摘要： Spinal cord injury (SCI) is one kind of serious injuries in Central Nervous System, accompanied with the disruption of blood-spinal cord barrier (BSCB). The study demonstrated that the disruption of BSCB is involved in the pathophysiologyic process of SCI. And the repair of BSCB will lead to a significant neuroprotective effect. BSCB is a metabolism barrier between the spinal cord tissue and blood circulation, which strictly keep the microenvironment of spinal cord. Heme oxygenase 1 (HO-1) is a stress inducible gene, played an important role in heme metabolism. Recently, the function of nuclear translocation draw the attention of people: the nuclear HO-1 protein itself might have an important role in the regulation of intracellular signal transduction. And HO-1 is not a traditional transcription factor, therefore, its regulation on gene expression is likely to play an indirect role. Recently, microRNAs (miRNA) have emerged as a critical class of regulators of gene expression. miRNA are endogenous small 21-23 nucleotide nonocoding RNAs that possess remarkable evolutionary conservation.It has been proved that, miRNA is widely present in eukaryotic cells, is one of the largest gene families, account for about 1% of the whole genome, plays an important role in the regulation of gene expression and biological growth process. Disorders of any miRNA will result in the change of the function of cells. Therapeutic application of microRNAs, such as miRNA-125a-5p, potentially could re-establish normal function of the brain vasculature in endothelial cell-based neurological diseases. At present, researchers began to pay attention to the effect of HO-1 on miRNA function, and found the HO-1 could regulate the expression of miRNA by binding to specific miRNA promoter or a specific sequence and then realize the protective role on cells. To search for miR-125a-5p which may be involved in the regulation of BSCB permeability induced by SCI. After the plasmid carried HO-1C Δ 23 was transfected into vascular endothelial cells, miRNA-125a-5p expression was markedly up-regulated and BSCB permeability induced by hypoxia and ROS was significantly reduced. Therefore, we persume that nuclear HO-1 is an important target for the regulation of BSCB through miRNA-125a-5p.The first aim of this study is to investigate the effects of nuclear HO-1 on structure and function of BSCB in vitro under different injury conditions. The second aim of this project are to investigate the role of miRNA-125a-5p in regulating the BSCB induced by nuclear HO-1. Finally, we investigated that the effect o exogenous recombinant adenovirus of nuclear HO-1 (Ad-HO-1C Δ 23) on BSCB permeability and the nervous function after SCI. This study will clarify that the role and mechanism of nuclear HO-1 in regulating the BSCB, providing the theoretical and experimental evidences to fully understand the related mechanisms, and create a new strategy for drug development in SCI.

英文关键词： spinal cord injury;vascular endothelial;vascular activity;blood-spinal cord injury;nuclear HO-1