基于“钙稳态--内质网应激--细胞凋亡”通路探究“肠道菌群--TMAO”加重心衰和芪参颗粒干预的机制

The heart failure has become a major public health problem with increased incidence rate, and its prevention and treatment are becoming difficulty and focus of cardiovascular diseases. The intestinal flora is called “the second genome of humans”, and increasing studies showed that its metabolite TMAO is closely related to heart failure. Currently, the clinical treatment of heart failure lacks effective intervention of Chinese medicine. Therefore, being sponsored by National Science and Technology Major Project(No.2012ZX09103201-011), the research group studied the principal pathogenesis of heart failure and created a Chinese medicine with independent intellectual property rights--Qishen granules based on principle of “nourishing qi and warming up yang, activating blood and resolving toxins”. The priliminary experiments and studies have proven that Qishen graules could treat chronic heart failure effectively. Thus, based on previous studies, researchers took rat with heart failure and H9C2 cardiomyocytes and left coronary artery ligation as objects, and based on “calcium homeostasis-endoplasmic reticulum stress-apoptosis” pathway, conducted study on aspects of cardiac function, histopathology, intestinal flora, overall metabolism and molecular regulation network through modern biological technology such as 16sRNA and targeted metabolomics, so as to expolre the mechanism of “intestinal flora-TMAO” aggravating the heart failure and the interventional mechanism of Qishen granules. This study could further reveal and enrich the scientific connotation of TCM in treating heart failure, and provide clues for the development of new drugs to treat heart failure, and promote clinical application of Chinese medicine in treating heart failure.

随着发病率的攀升，心衰已成为全球性重大公共卫生问题，其防治也成为心血管学科面临的重点和难点。肠道菌群被称为“人类的第二基因组”，越来越多研究显示肠道菌群代谢产物TMAO与心衰关系密切。目前临床治疗心衰缺乏有效的干预中药，故针对心衰核心病机，依托国家科技重大专项（编号2012ZX09103201-011），课题组以“益气温阳、活血解毒”立法，创制具有自主知识产权中药组方--芪参颗粒。芪参颗粒前期基础实验证实能够有效治疗慢性心衰，因此在前期研究的基础上，本研究以H9C2心肌细胞损伤模型和左冠状动脉结扎术致大鼠心衰模型为研究对象，围绕“钙稳态--内质网应激--细胞凋亡”通路，借助16sRNA和靶向代谢组学等现代生物学技术，从心脏功能、组织病理、肠道菌群、整体代谢、分子调控网络多层次进行研究，探究“肠道菌群--TMAO”加重心衰和芪参颗粒可能的干预机制，以进一步揭示和丰富中医药治疗心衰的科学内涵。

随着发病率的攀升，心衰已成为全球性重大公共卫生问题，其防治也成为心血管学科面临的重点和难点。肠道菌群被称为“人类的第二基因组”，越来越多研究显示肠道菌群代谢产物TMAO与心衰关系密切。目前临床治疗心衰缺乏有效的干预中药，故针对心衰核心病机，依托国家科技重大专项（编号2012ZX09103201-011），课题组以“益气温阳、活血解毒”立法，创制具有自主知识产权中药组方--芪参颗粒。芪参颗粒前期基础实验证实能够有效治疗慢性心衰，因此在前期研究的基础上，本研究以H9C2心肌细胞损伤模型和左冠状动脉结扎术致大鼠心衰模型为研究对象，围绕“钙稳态--内质网应激--细胞凋亡”通路，借助16sRNA和靶向代谢组学等现代生物学技术，从心脏功能、组织病理、肠道菌群、整体代谢、分子调控网络多层次进行研究，探究“肠道菌群--TMAO”加重心衰和芪参颗粒可能的干预机制，以进一步揭示和丰富中医药治疗心衰的科学内涵。 本研究初步验证了课题最初提出的设想，TMAO会加重心衰，造成钙稳态的失衡和内质网应激，而芪参颗粒干预后，心功能好转，胞浆钙离子浓度趋于正常水平，内质网应激程度减弱。但血浆中TMAO浓度并未降低，根据肠道菌群的结果，可能是因为芪参颗粒上调了某些菌属，例如Blautia/ Bacteroides的丰度，这些菌属的其他代谢产物对于心血管系统有益，而恰好又含有促进胆碱转化为TMA的关键酶。同时我们关注到脂肪酸和葡萄糖代谢对心肌的影响，芪参颗粒能改善心衰模型的心功能，减轻心肌重构。芪参颗粒可显著降低血清TC、TG和LDL-C水平。芪参颗粒上调了介导FA摄取、转运至线粒体和β-氧化的蛋白(FAT/CD36、CPT1A、ACADL、ACADM、ACAA2和SCP2)以及FA代谢的上游转录调控因子(PPARα、RXRα、RXRβ和RXRγ)。在葡萄糖代谢方面，芪参颗粒通过降低LDHA抑制糖酵解活性，通过降低PDK4刺激葡萄糖氧化。芪参颗粒通过增加SUCLA2、CKMT2和PGC-1α，同时降低UCP2，促进三羧酸循环，促进ATP从线粒体向细胞质运输，恢复线粒体功能。线粒体功能障碍也是导致内质网应激发生的重要因素之一。