从ERS细胞凋亡信号通路探讨降糖舒心方对糖尿病心脏重塑影响的研究

Increasing morbidity and mortality have made heart failure (HF) become the most major cardiovascular disease of the 21 century in recent years. Diabetes mellitus is a world prevalent disease with increasing prevalence, followed with the rising number of the patients with coronary macrovascular disease, concomitant hypertension, microvascular complication, and cardiac autonomic neuropathy. It has been demonstrated now that the fundamental mechanisms responsible for the development and progression of HF is myocardial remodeling, which is defined as the changes of heart in structure, including the accumulation and altered composition of extracellular matrix(ECM). Myocardial remodeling is the common character, as a result of the development of various cardiac diseases. Cardiomyocyte apoptosis plays a critical role in myocardial remodeling, and endoplasmic reticulum stress (ERS) is one of intrinsic apoptosis pathways. The endoplasmic reticulum (ER) is a central organelle entrusted with lipid synthesis, calcium homeostasis, protein folding and maturation. Various factors, including oxidative stress, ischemia, disturbance of calcium homeostasis, and overexpression of incorrectly folded proteins, can interfere with ER function and lead to ERS. Multiple pathogenic factors of diabetes, such as hyperglycemia, hyperlipidemia, homocysteine(Hcy), Ang II, hypoxia and so on, can invoke ER stress and initiate the cardiac inflammation, which make a vicious cycle, and eventually lead to cell apoptosis and associated myocardial remodeling . Therefore, blocking endoplasmic reticulum stress-related cells apoptosis pathway can act as a potential approach for interrupting myocardial remodeling. 　 According to Traditional Chinese medicine（TCM）theory, diabetic myocardial remodeling is essentially belonged to the categories of Xiao Ke complicated with cardiopathy. Yin debilitation and Qi deficiency, Combined with dryness-heat, are the Xiao Ke cardiopathy basic constitution. With the development of the disease, heart Qi unable to promote the blood circulation, leading to Qi stagnation and blood stasis; Or the accumulation of internal heat damage body fluid, transform into fire and result in internal exuberance of fire-heat that may in turn consume or scorch the body Yin-fluids and blood, and subsequently lead to blood and fluid stasis and change into stasis toxin.Therefore, the co-existence of deficiency of both Qi and Yin, blood stasis and toxin accumulation is the important intrinsic pathogenesis of diabetic myocardial remodeling. The strategy of "Supplementing Qi and Nourishing Yin, Activating blood circulation and Detoxifying"（SNAD）is the basic method of treating diabetic myocardial remodeling.The purpose of this study is to explore the effect of JIANG TANG SUXI decoction，which possessing SNAD, confirm that SNAD may be one of the effective methods for the prevention and treatment of diabetic myocardial remodeling.

糖尿病心脏病(DC)是糖尿病(DM)常见的并发症，是导致糖尿病患者死亡的主要原因。目前已明确，导致心力衰竭发生发展的基本机制是心脏重塑，因此如何防止和延缓心脏重塑的发展是目前研究的热点。心肌细胞凋亡在心脏重塑进展中起着重要作用，而内质网应激(ERS)是导致细胞凋亡的原因之一。DM的多种病理因素，均易诱发ERS，产生严重而持久的ERS，超过内质网自我修复能力，使PERK、ATF6 及IRE-1与BIP分离，激活下游的凋亡信号分子：CHOP、c-JNK、Caspase12，导致心肌细胞凋亡。中医理论认为DM属于消渴病范畴，气虚致瘀，阴虚致内热，热瘀内蕴可化毒，因此"气阴两虚、瘀毒内蕴"是DC的主要病机。降糖舒心方有益气养阴、活血解毒的功能。本课题在前期研究的基础上，从ERS细胞凋亡信号通路探讨降糖舒心方对DC作用，揭示其抑制心脏重塑的分子机制，为"滋阴益气活血解毒"对DC的治疗提供科学依据。

目前已明确，导致心力衰竭发生发展的基本机制是心脏重塑，心肌细胞凋亡在心脏重塑进展中起着重要作用。糖调节蛋白-78 (GRP78)是内质网应激(ERS)的感受分子，内质网处于稳态时，GRP78与活化转录因子-6 (ATF6)、蛋白激酶R样内质网激酶(PERK)和肌醇需求酶1(IRE-l)的结构域结合；在持续而严重的ERS发生时，GRP78将与PERK、ATF6、IRE-1解离，解离后的PERK、ATF6和IRE则激活下游的CCAAT增强子结合蛋白同源蛋白(CHOP)、半胱氨酸天冬氨酸蛋白酶-12 (Caspase12)、c-JUN氨酸末端激酶(JNK)三个凋亡信号通路，导致细胞凋亡。ERS作为多种应激源的共同通路，通过非折叠蛋白反应(UPR)信号与炎症反应偶合，连接代谢异常和ERS凋亡反应过程。中医理论认为糖尿病(DM)属于消渴病范畴，“气阴两虚、瘀毒内蕴”是DM合并心脏病的主要病机。针对“气阴两虚，瘀毒内蕴”之消渴并心病病机，本研究以SD糖尿病大鼠为实验对象，以益气养阴、活血解毒为治法，以降糖舒心方为组方，通过观察：①诱发ERS的糖尿病相关指标；②心电图及心脏重塑体外数据；③心肌病理形态及心肌胶原纤维的表达；④心肌细胞凋亡水平；⑤ERS凋亡信号分子的mRNA转录及其功能蛋白表达水平，从ERS凋亡的分子信号通路方面，探讨降糖舒心方作用机制。本研究表明，降糖舒心方能抑制胰岛素抵抗，减轻氧化应激所导致的炎症反应，降低ERS标志性分子的mRNA及其功能蛋白的表达，减轻“氧化应激-内质网应激-细胞凋亡”的偶联反应，抑制ERS相关凋亡的通路，减少心肌细胞凋亡，对心肌组织结构及超微结构起到保护作用，提高心功能，发挥“滋阴益气、活血解毒”的多环节、多途径、多靶点的中医药整体调节防治特色。项目研究过程中，发表论文10篇(其中外文论文2篇，中文核心6篇，科技核心2篇)，研究成果已在国内和国际会议上交流宣读，培养研究生2人，本科生7人，课题组成员科研水平得到了提高，职称1人由初级晋升中级，1人由中级晋升副高，1人由副高晋升正高。项目投入经费45万元，支出24.39万元，各项支出基本与预算相符，剩余经费20.61万元计划用于本项目研究后续支出。