藏药三味檀香散调控RAS稳态及保护HAPH大鼠右心室结构和功能的研究

High altitude pulmonary hypertension (HAPH) is a chronic high altitude disease which seriously affects the health of residents in high altitude, and right heart failure is the leading cause of death. In the case of primary etiology is difficult to eliminate, therefore looking for new view to protect the right ventricular structure and function is expected to provide a new strategy for the prevention and treatment of HAPH. We focus on steady-state change of heart and lung tissue ACE-Ang II-AT1 axis/ACE2-Ang (1-7) MAS axis. Our previous study showed that the Tibetan medicine Sanwei Tanxiang powder not only reduced HAPH, but also significantly decreased injury of myocardial tissue morphology and ultrastructure of mitochondria by regulating the expression of Ang II and ET-1 in the right ventricle. Does Sanwei Tanxiang powder preserve the structure and function of right ventricle by indirectly attenuating overload or by directly protecting cardiac muscle? If the protect effect of this medicine was based on regulating homeostasis of ACE-Ang II-AT1 axis/ ACE2-Ang(1-7)-Mas axis in heart and lung? To answer these questions, we proposed to RAS homeostasis as the research target, to right ventricular function, right ventricular-arterial coupling, pulmonary artery mechanical properties as detection index using echocardiography, laser scanning confocal microscope detection, to deeply explain the mechanism of traditional Tibetan medicine, thus provides new perspective for the prevention and treatment of chronic mountain sickness.

高原低氧性肺动脉高压（HAPH）是严重影响高原居民健康的慢性高原病，右心衰竭是其首要的死亡原因。在原发病因难以消除的情况下，保护右心室的结构和功能，有望为防治HAPH提供新的策略。课题组关注心肺组织ACE-Ang II-AT1轴/ACE2-Ang(1-7)-Mas轴的稳态。前期研究发现，藏药三味檀香散不仅可以改善HAPH，而且通过调控右心室AngⅡ及ET-1等因子的表达，明显减轻心肌组织形态学及线粒体超微结构的损伤。三味檀香散是通过减轻后负荷还是直接作用于心肌从而保护了HAPH大鼠右心室的结构和功能？其作用是否与调控ACE-Ang II-AT1轴/ACE2-Ang(1-7)-Mas轴的稳态有关？我们拟定以RAS稳态为研究靶点，以右心室功能、右心室-肺动脉动态耦合、肺动脉力学性能为指标，利用超声心动描记术、激光共聚焦等检测手段，深入阐释传统藏药的作用机制，以期为慢性高原病的防治提供新的视角。

本项目关注右心室结构和功能的保护在HAPH发展中的关键作用。我们发现：（1）三味檀香散水提物舒张肺小动脉血管环的作用与PGI2-cAMP途径，NO-cGMP途径和K+通道的开放有关；（2）三味檀香散可降低HAPH大鼠的mPAP和RVHI、改善右心室肥厚、降低右心室纤维化，但对大鼠体循环血压，心肺脏器体重比及血细胞计数无明显影响；（3）三味檀香散可抑制HAPH大鼠肺小动脉平滑肌增殖，提高肺动脉顺应性，其作用与抑制Cyclin D1和CDK4，提升p27Kip1表达，抑制胶原蛋白的合成有关；（4）三味檀香散抑制HAPH大鼠肺小动脉及肺组织ACE-AngII-AT1R轴因子的表达、激活ACE2及Mas因子的表达，同时降低肺组织内NA/NE、EPI、DA及ET-1的水平，综合发挥其舒张肺动脉，抑制增殖的作用。（5）三味檀香散改善HAPH大鼠右心室肥厚和纤维化的机制与抑制右心室组织中ACE-AngII-AT1R 轴因子表达和激活ACE2-Ang(1-7)-Mas轴因子表达，并恢复ACE-AngII-AT1R 轴与ACE2-Ang(1-7)-Mas轴的稳态，同时降低右心室组织内肾上腺素、去甲肾上腺素和多巴胺的水平有关；（6）三味檀香散（含挥发油）可以改善HAPH大鼠右心室功能，恢复RV-PA偶联，逆转血流动力学和血液学指标，减轻右心室重构；（7）三味檀香散对HAPH大鼠右心功能的保护与抑制ROCK信号通路及其下游信号分子的表达有关。（8）从三味檀香散水提物中鉴定出35种主要的化学成分。（9）从三味檀香散挥发油中共鉴定出35种化学成分。（10）异槲皮苷、熊果酸、利卡灵B、去氢二异丁香酚和2-(2-hydroxypropan-2-yl)-9-(3-methylbut-2-enyl)-2,3-dihydrofuro[3,2-g]chromen-7-one是抑制ROCK蛋白的潜在化合物。