基于NF-kB/HIF-1a信号通路交叉对话的朝药泽兰改善糖尿病心肌病的作用机制研究

Diabetic cardiomyopathy (DC) is a special diabetic complication characterized by glucose and lipid metabolism disorder, myocardial fibrosis, microvascular disease and insulin resistance, caused by oxidative stress and inflammatory reaction in the pathogenic process of DC. Hypoxia inducible factor-1a (HIF-1a), an oxygen-dependent transcriptional factor which plays a key role in oxygen homeostasis, and NF-kB, a major nuclear transcription factor which could regulate proinflammatory cytokine expression, were both important therapeutic target for DC and regulated by the upstream of MAPKs (ERK1/2, JNK, P38) and PI3K/Akt signaling pathway as well as activated the downstream of vascular endothelial growht factor (VEGF), haem oxygenase-1(HO-1), transforming growth factor-beta1 (TGF-beta1), and matrix metalloproteinase (MMP) participated in myocardial protection or injury of DC. Lycopus lucidus Turcz (LLT), a perennial herb widely used as the ‘Taiyin’ Medicine of Korean Traditional Medicine (KTM), has the function of promoting blood circulation, removing blood stasis, accelerating ‘Qi’, and eliminating ‘Zhuo’. According to KTM principle proposed that the drugs must be taken on the basis of ‘Constitution’, LLT is used to treat diabetes and its cardiovascular complications caused by ‘Taiyin’ physique characteristics of ‘blood Zhuo and Qi retardarce’. In our previous studies, we found that the LLT reduced the levels of blood glucose and lipid, improved cardiac systolic and diastolic functions, and upregulated protein levels of HIF-1a with down-regulation of NF-kB p65. Then, it would be provided DC injury models (in vivo), and myocardiac cells rat model wiht high glucose puls hypoxia injury (in vitro) in our projects. Overall, the purpose of the present study was to evaluate the therapeutic effects on DC by LLT and illuminated whether HIF-1a/NF-kB signaling pathway was regulated by upstream of MAPKs and PI3K/Akt signaling pathway. It would be provided essential theoretical and experimental evidence to KTM research for anti-DC injury.

糖尿病心肌病（DC)以糖脂代谢紊乱、心肌纤维化、微血管病变及胰岛素抵抗为主要特征，其病变涉及氧化应激与炎症反应。缺氧诱导因子-1（HIF-1）和核转录因子-kB(NF-kB) 分别是氧化应激与炎症反应的关键转录因子，受上游的MAPKs和PI3K/Akt信号通路的调控，从而激活其下游的VEGF, HO-1等基因表达，在DC心肌细胞损伤过程中发挥重要作用。泽兰属于朝医太阴人要药，临床常用于治疗“血浊气涩”引发的2型糖尿病及其合并心血管病变。前期研究发现，泽兰降低2型糖尿病大鼠血糖、血脂水平，改善心功能指标，上调HIF-1a表达，并抑制P65蛋白表达。为阐明泽兰改善DC的药用机制，本课题组拟从细胞、分子和整体水平，以NF-kB和HIF-1a为切入点，探讨泽兰通过对MAPKs和PI3K/Akt信号通路调节NF-B和HIF-1a的作用机制，为今后朝医药防治DC的基础研究提供必要的理论与实验依据。

糖尿病心肌病（DCM）是一种在糖尿病病程中以糖、脂代谢紊乱及心肌微血管病变的基础上引发缺血性心肌广泛灶性坏死为特点的特异性心脏病变，可涉及心肌细胞内氧化应激增强和炎症反应。缺氧诱导因子-1a（HIF-1a）作为细胞氧稳态调节的调控因子，与免疫炎症调节作用的核转录因子-kB(NF-kB)在DCM发病过程中共同发挥着重要作用，且两种信号通路存在交叉对话关系。因此，在观察HIF-1a和NF-kB信号通路之间在缺氧应激和炎症反应中的交叉对话基础上，通过发现更多新源药物更深入地研究抗DCM的作用靶点是DCM治疗的迫切需要。朝药泽兰可通过调控HIF-1a和NF-kB信号通路干预DCM的发病过程。体内实验使用高脂高糖加腹腔注射链脲佐菌素的方法建立大鼠糖尿病心肌病模型，通过灌胃朝药泽兰可调控PI3K/Akt/mTOR信号通路降低HIF-1a表达水平，有效改善心功能和糖代谢紊乱，并调节AMPK/TFG-beta/Smad2/3信号通路有效干预糖尿病合并心肌纤维化病程。此外，万金文武汤（含泽兰）通过减少p38 MAPK、NF-kB、HIF-1a等表达对DCM大鼠心肌发挥抗炎、抗氧化应激的作用。体外实验证实，朝药泽兰及其有效成分通过调控PI3K/Akt/mTOR信号通路和HIF-1a表达对心肌缺血再灌注损伤发挥保护作用，与体内实验结果一致。综上所述，朝药泽兰对拮抗糖尿病心肌病有显著的改善作用，具有潜在的药理学治疗特性。但是作为新源药物仍需要进一步深入研究，确定其确切的糖尿病心肌病治疗机制。