| With the gradually increasing of the aging population, the morbidity and mortality of ischemic heart disease is vastly increasd in recent years. Drug therapy is one of the most important ways in the clinical therapeutics of ischemic heart disease, especially for patients of coronary artery stenosis, which can not be treated by surgery. In china, a large number of traditional Chinese medicines were used for the prevention and treatment of ischemic heart disease, but the active componets and mechanisms of action of many traditional Chinese medicines are still unclear. Therapeutic angiogenesis is a recently proposed approach for the treatment of ischemic heart disease. It is belived that angiogenesis in ischemic region of myocardium may lead to the construction of new collateral circulation and resume blood supply. Therefore, studies on therapeutic angiogenesis induced by traditional Chinese medicine may play important roles in the treatment of ischemic heart disease.QI-SHEN-YI-QI showed a significant effect in treatment of ischemic heart disease, but the mechanisms were not clear. In this study, experimental techniques of pharmacology were used to study the angiogenic mechanisms of QI-SHEN-YI-QI. In vitro experiments were performed to study the accumulation of hypoxia-inducible factor-1α(HIF-1α) and angioenesis by astragaloside IV. Then metabolomics technique was used to study the effect of QI-SHEN-YI-QI on regulation of endogenous metabolites in rat plasma. The main contents of dissertation include:1. This study aims to determine the possible cardioprotective effects of QI-SHEN-YI-QI and its angiogenic mechanism. Male Sprague-Dauley rats were subjected to ligation of left anterior descending artery (LAD). Triphenyltetrazolium chloride (TTC) staining, immunohistochemistry, real-time PCR and western blotting were used to study the agiogenic effect of QI-SHEN-YI-QI. The results showed that QI-SHEN-YI-QI significantly reduced infarct size and increased density of vessel. The mRNA levels of VEGF, bFGF and PDGF-B were increased in QI-SHEN-YI-QI treated group compared to myocardial infarct group. Western blotting results further demonstrated that protein expression of VEGF and bFGF were also notably raised in QI-SHEN-YI-QI treated group. Our study demonstrated that therapeutic angiogenesis induced by QSYQ may lead to neovascularization and conferring myocardial protection by increaing expression of angiogenic factors.2. This study aims to determine the HIF-la accumulation and angiogenic effect of astragaloside IV and its underlying mechanisms. MTT assay, western blotting, real-time PCR, immunofluorescence, transwell, matrigel and chick chorioallantoic membrane (CAM) assays were used to study the effect of astragaloside IV on accumulation of HIF-1αand angiogenesis. The results showed that astragaloside IV significantly improved cell viability after hypoxia and stimulated HIF-1αaccumulation during hypoxia. Mechanism studies revealed that astragaloside IV did not affect the degradation of HIF-1αprotein or the mRNA level of HIF-1α. In contrast, astragaloside IV apparently activated the PI3K/AKT pathway, which regulates HIF-la protein synthesis. Moreover, HIF-1αwas translocated to nuclear and mRNA level of VEGF was significantly increased in astragaloside IV treated group. Astragaloside IV also stimulated cell migration, increased tube formation and promoted angiogenesis in chick chorioallantoic membrane assay. All angiogenic effects of astragaloside IV were reversed by PI3K inhibitor LY LY294002. Our data suggested that astragaloside IV was a novel regulator of HIF-1αand angiogenesis through the PI3K/AKT pathway in HUVECs exposed to hypoxia.3. GC-MS was employed to profiling the effect of QI-SHEN-YI-QI on endogenous metabolites in myocardial infarcted rats. The results showed that seven metabolites related to energy metabolism and seven metabolites related to metabolism of amino acids were significantly increased in the plasma of myocardial infracted rats. However, administration of QI-SHEN-YI-QI regulated those metabolites in energy and amino acids metabolism to the normal level. It suggested that QI-SHEN-YI-QI may exert its protective effect against myocardial ischemia through regulation of energy and amino acids metabolism.Taken together, QI-SHEN-YI-QI promoted angiogenesis by collaborative effect of VEGF, bFGF, PDGF-B and protected against myocardial ischemia through regulation of energy and amino acids metabolism. Astragaloside IV improved cell viability during hypoxia, stimulated HIF-1αaccumulation by P13K/AKT pathway, and increased mRNA level of VEGF, which may contribute the angiogenesis effect during hypoxia. |
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