Investigation of anti-atherogenic effects of the alpha-tocopherol long-chain metabolites alpha-13-OH and alpha-13-COOH

动脉粥样硬化及其并发症如中风和心肌梗塞是西方工业化社会的主要死亡原因。因此，对潜在机制和治疗方法的研究比以往任何时候都更有需求。基于从体外和动物研究获得的若干结果，维生素E，特别是其最活性形式α-生育酚，被认为是预防动脉粥样硬化的治疗剂。在肝脏α-生育酚代谢中，长链代谢产物α-13-OH和α-13-COOH是通过细胞色素P（α）4F 2/3A 4依赖的ω-羟基化，然后ω-氧化形成的。我们的初步数据促进了这样的假设，即α-生育酚的长链代谢物存在于人血清中，并且至少是比α-生育酚更有效地介导效应的生物活性分子。因此，α-13-OH和α-13-COOH的抗动脉粥样硬化作用应在体外和体内与α-生育酚进行比较研究。该项目的目的是揭示α-生育酚的长链代谢物，即α-13-OH和α-13-COOH的分子作用模式，以及它们对（i）血小板功能，（ii）Apoe敲除小鼠模型中动脉粥样硬化，和（iii）改良的Apoe敲除小鼠模型中的动脉粥样硬化斑块稳定性。这种小鼠模型在斑块内出血、薄或破裂的纤维帽、腔内血栓形成和新血管形成等特征方面与人类不稳定斑块具有可比性。为了全面研究α-长链代谢物对动脉粥样硬化、血小板功能和斑块稳定性的影响，将采用创新的分子影像学技术、分子生物学方法、组织学染色和脂质组学分析等手段，研究α-长链代谢物对动脉粥样硬化的影响，斑块稳定性和血小板功能将有助于评估维生素E在心血管并发症中的真实的作用和分子作用模式。该项目将提供体外发现的长链代谢物的抗动脉粥样硬化特性是否可以在体内得到证实的重要信息。这将有助于完整表征α-长链代谢物作为调节分子的生物学效应及其在动脉粥样硬化发病机制中的重要性。

Atherosclerosis and its complications such as stroke and myocardial infarction are a leading cause of death in Western industrialized societies. Hence, research on underlying mechanisms and therapeutic approaches are on greater demand than ever. Based on several results obtained from in vitro and animal studies, vitamin E and in particular its most active form a-tocopherol, was considered as a therapeutic agent for preventing atherosclerosis. However, the promising reports on vitamin E failed to be reproduced in humans.In hepatic a-tocopherol metabolism the long-chain metabolites a-13-OH and a-13-COOH are formed by cytochrome P (CYP)4F2/3A4-dependent omega-hydroxylation followed by omega-oxidation. Our preliminary data promote the hypothesis that the long-chain metabolites of a-tocopherol occur in human serum and are at least bioactive molecules mediating effects more effectively than a-tocopherol. Therefore, anti-atherogenic effects of a-13-OH and a-13-COOH should be investigated in comparison to a-tocopherol in vitro and in vivo.The aim of the project is to unravel the molecular modes of action of the long-chain metabolites of a-tocopherol, namely a-13-OH and a-13-COOH, and their effects on (i) platelet function, (ii) atherosclerosis in the Apoe knockout mouse model, and (iii) atherosclerotic plaque stability in a modified Apoe knockout mouse model. This mouse model is unique in its comparability to human unstable plaques in such characteristics as intraplaque hemorrhage, thin or disrupted fibrous caps, intraluminal thrombosis and neovascularization. In order to comprehensively study the effects of the long-chain metabolites on atherosclerosis, platelet function and plaque stability innovative molecular imaging technologies, molecular biological methods, histological stainings and lipidomic analysis will be used.The investigation of the effects of a-long-chain metabolites on atherosclerosis, plaque stability and platelet function will help to assess the real contribution and the molecular modes of action of vitamin E in cardiovascular complications. The project will provide important information whether the anti-atherogenic properties of a-long-chain metabolites found in vitro can be confirmed in vivo. This will contribute to the complete characterization of the biological effects of a-long-chain metabolites as regulatory molecules and their importance for the pathogenesis of atherosclerosis.