基于miRNA与RAS系统探讨当归降压的分子机制研究

Essential hypertension is a kind of complicate multifactorial disease，and its development is determined by a combination of genetic susceptibility and environmental factors.it is an increasingly important health problem , affecting as many as 1 billion people worldwide with high associated morbidity and mortality. Hypertension often lead to other disease,such as diabetes，coronary heart disease，renal disease，myocardial infarction and so on.How can we prevent and cure this disease are the most important research field to cadiovascular researcher.RAS over-activity is one of the important pathogenesis of hypertension.In these days,more and more medical scholars pay more attention to microRNA which has made great progress in the field of cadiovascular.Researcher have discovered many miRMA related with Hypertension.Many aspects of the development of essential hypertension at the molecular level are still unknown. The elucidation of these processes regulated by microRNAs and the identification of novel microRNA targets in the pathogenesis of hypertension is a highly valuable and exciting strategy that may eventually led to the development of novel treatment approaches for hypertension.Angelica sinensis,one of the genuine medicinal herbs in Gansu,Especially in country of Minxian,where have high quality Angelica Sinensis.Its effects include: enrich the blood;activating blood circulation to dissipate blood stasis and so on.The recent research has proved that Angelica Sinensis can help lower blood pressure.Until now,There wasn't similar research about the effect of Angelica Sinensis on microRNA expression profile and function in essential hypertension.Our study material is spontaneously hypertensive rats,MiRNAs Profile will perform using miRNA array kit,and were quantitative RT-PCR for the different miRNA expression.Classified the different expression miRNA with cluster analysis.MiRanda, Target Scan and PicTar were utilized for predictive analysis of miRNAs and target genes. Luciferase report gene screening were constructed.The regulatory relationship of miRNAs and target genes were then verified by using Western Blot.So we can explore the effect of Angelica sinensison on target gene of hypertension especially to miR155 and its target gene-AT1R,we still clarified the role of ERK signal pathway and examine the expression of ACE、ACE2、PRA、AngⅡ、Ang1-7 、ERK and Mas Receptor .By this studying,we can not only clarity the miRNA mechanism of about the herbs lower blood pressure,but also establish solid experiment foundation for pharmacological study of traditional Chinese crude drug in Gansu.We still provide a new treatment target to RNA interfere therapy and supply much help to this research and development of new drug in essential hypertension.Advanced discussion in microRNA that may be important in treating hypertension.

原发性高血压是一种多因素所致的疾病，其中RAS系统过度活动是原发性高血压发病的重要机制之一； miRNA是一种新型的基因表达调控因子，目前发现了多种与高血压相关的 miRNA，其中包含作用于RAS系统的miRNA并以miR155为代表之一。当归是甘肃的道地药材，尤以甘肃岷县当归品质最佳。研究已证实当归具有降压的作用。有关当归提取液对高血压 miRNA的表达及其相关靶基因的影响未见报道。本研究拟以自发性高血压鼠为研究材料，分析当归提取液对高血压miRNA基因表达谱尤其对RAS系统miR155表达的影响，探索当归提取液对miR155靶基因及其相关信号通路表达调控的影响；同时分析当归提取液对RAS系统中ACE,ACE2酶及相关血管活性物质表达的影响，从分子层面阐明当归降血压的机制，为我省道地中药材的药理研究奠定实验基础，也为今后高血压的新药研发及RNA干扰治疗高血压提供新的靶点。

原发性高血压是一种多因素所致的疾病，其中RAAS 系统过度活动是原发性高血压发病的重要机制之一; miRNA 是一种新型的基因表达调控因子，目前发现了多种与高血压相关的 miRNA，其中包含作用于RAAS系统的miRNA并以miR155 为代表之一。当归是甘肃的道地药材，尤以甘肃岷县当归品质最佳。研究已证实当归具有降压的作用。本研究以自发性高血压鼠为研究材料，分析当归挥发油对高血压miRNA基因表达谱的影响及对RAAS系统中miR155 表达的干预作用，探索当归对miR155 靶基因及其相关信号通路表达调控的影响；同时分析当归挥发油对RAAS 系统中ACE,ACE2 酶及相关血管活性物质表达的影响，研究结果发现当归挥发油对自发性高血压大鼠血压有干预作用，可有效降低大鼠收缩压，以高剂量组为甚；同时对SHR心肌组织具有一定的保护作用。当归对高血压 miRNA基因表达谱有干预作用:通过对miRNA基因表达谱的分析发现，当归组呈差异性表达的miRNA共29个，表达上调13个，表达下调16个，通过GO与KEGG富集分析，当归挥发油可能作用于胰岛素相关信号通路及VEGF信号通路影响内皮功能来发挥血压调节作用，同时可能通过调节细胞凋亡信号通路抑制心肌纤维化或心肌肥大来保护心肌细胞。研究结果同时发现当归挥发油对miR155表达的影响甚微，但可以有效降低AT1R及相关信号通路ERK的mRNA及蛋白表达量，推测当归有可能通过其他途径作用于AT1R影响高血压的发生发展。当归挥发油也对RAAS系统产生影响，本项研究结果表明当归干预后，SHR血中肾素水平有降低趋势，AngⅡ水平显著降低，Ang(1-7)水平高于模型组，ACE的mRNA及蛋白表达水平均有所降低，而ACE2及Mas受体的蛋白表达水平显著升高，说明当归可以作用于ACE2 /Ang（1-7）/Mas 受体轴，通过拮抗ACE/ AngⅡ/AT1R的作用，激活ACE2基因，将 AngⅡ转化为 Ang（1-7）,促进Mas受体的表达而发挥降压的作用。本项研究从分子层面阐明了当归对血压的干预机制，为我省道地中药材的药理研究奠定实验基础，也为今后高血压的新药研发及mi RNA干扰治疗高血压提供新的靶点。