基于Ghrelin介导的PI3K/Akt/eNOS信号通路研究高血压从阳明论治的分子机制

Hypertension is the most important risk factor for cardiovascular disease, which has now become the number one killer that threatens the Chinese population health. Our previous clinical study demonstrated that selecting acupoints on the Yangming meridian exerts good antihypertensive effect. However, the mechanism is unclear. PI3K/Akt/eNos signal pathway has been discovered to be a new antihypertensive target. Ghrelin is an important factor in the regulation of this pathway. In addition, our previous animal study concluded that electro-acupuncture on the acupoints of YangMing Meridian is able to promote the gastrointestinal secretion of Ghrelin. Therefore, we hypothesized that electro-acupuncture on the acupoints of YangMing Meridian exert endothelial protection and antihypertensive effect via the promotion of gastrointestinal secretion of Ghrelin, futher activating PI3K/Akt/eNos signal pathway. We select spontaneous hypertensive rats as research subject. By means of multi-disciplinary technologies such as wireless telemetry、immunohistochemistry、post-transcriptional gene silencing、RT-PCR , based on the Ghrelin modulated PI3K/Akt/eNOS signal pathway, on the one hand, we will investigate the influence of blood pressure、endothelial function、Ghrelin and PI3K/Akt/eNOS signal pathway with the treatment of electro-acupuncture on the acupoints of YangMing Meridian in a positive way; on the other hand, we will study the influence with additional Ghrelin gene silencing and external treatment with Ghrelin in a negative way. So as to clarify the molecular mechanism of acupuncture on Yang Ming meridian for hypertension.

高血压是心血管疾病最重要的危险因素，已成为我国居民健康的头号杀手。前期研究发现高血压从阳明论治，具有良好的降压效应，但其作用机理尚未明确。PI3K/Akt/eNos信号通路是新近发现的降压靶点，Ghrelin是调控该通路的重要因子。且前期研究发现电针阳明经穴可促胃肠分泌Ghrelin。因此，我们提出“电针阳明经穴通过促胃肠分泌Ghrelin，激活PI3K/Akt/eNOS信号通路，保护内皮功能，从而产生降压效应”的工作假说，以自发性高血压大鼠为研究对象，采用无线遥测、免疫组化、基因沉默、RT-PCR等方法，从Ghrelin及PI3K/Akt/eNOS信号通路入手，一方面通过正向观察电针阳明经穴对自发性高血压大鼠血压、内皮功能、Ghrelin及PI3K/Akt/eNOS信号通路的影响；另一方面通过Ghrelin基因沉默及外源性Ghrelin干预反向进行观察，以明确高血压从阳明论治的分子机制。

高血压是心血管疾病最重要的危险因素，已成为我国居民健康的头号杀手。前期研究发现高血压从阳明论治，具有良好的降压效应，但其作用机理尚未明确。PI3K/Akt/eNOS信号通路是新近发现的降压靶点，Ghrelin是调控该通路的重要因子。且前期研究发现电针阳明经穴可促胃肠分泌Ghrelin。因此，我们提出“电针阳明经穴通过促胃肠分泌Ghrelin，激活PI3K/Akt/eNOS信号通路，保护内皮功能，从而产生降压效应”的工作假说。.本研究以自发性高血压大鼠为研究对象，采用无线遥测、免疫组化、免疫蛋白印迹等技术，以Ghrelin及PI3K/Akt/eNOS通路为切入点，通过外源性的给予Ghrelin及Ghrelin基因沉默，从正、反向观察电针阳明经穴对自发性高血压大鼠血压、血管形态学、内皮保护因子以及Ghrelin和PI3K/Akt/eNOS通路的影响，以明确高血压从阳明论治的分子机制。.本研究结果发现：电针手阳明大肠经人迎穴及曲池穴、足阳明胃经足三里穴及丰隆穴可有效降低自发性高血压大鼠的收缩压和舒张压，增加Ghrelin和NO的浓度，降低ET-1及TXA2水平，减轻血管壁受损程度，降低血管内皮细胞脱落程度，保护血管内皮，并上调PI3K/Akt/eNOS通路蛋白和mRNA表达；给予外源性Ghrelin后，电针阳明经穴的降压效应、血管内皮保护作用及PI3K/Akt/eNOS通路蛋白和mRNA的表达进一步增强；而Ghrelin基因沉默后，电针阳明经穴的降压效应、血管内皮保护作用及PI3K/Akt/eNOS通路蛋白和mRNA的表达减弱。上述结果表明，电针阳明经穴的降压效应与Ghrelin及PI3K/Akt/eNOS信号通路介导的血管内皮保护作用相关。本研究从正、反向验证了前期提出的工作假说，初步阐明了电针阳明经穴降压的分子生物学机制，有利于丰富针刺降压的理论，有助于针刺降压的临床推广应用。