The role of ApoE genotype on blood-brain barrier functions

概述：本项目的目的是利用动物模型和一系列体内互补的技术手段，破译载脂蛋白E(ApoE)基因对血脑屏障(BBB)功能的作用。**背景：BBB控制内源性和外源性化合物在大脑中的进出，从而调节大脑的动态平衡。最近的证据表明，脑功能取决于载脂蛋白E基因，可能是通过改变血脑屏障的功能和结构完整性，但分子机制仍不清楚。**最近的进展：最近几年，我们积累的初步数据表明，在APOE2、E3和E4小鼠中，重要的血脑屏障相关参数受到载脂蛋白E基因的严重影响。**特定目的：将比较特定表达人载脂蛋白E亚型E2、E3或E4的小鼠的血脑屏障特性。技术方法将结合原位脑灌注、免疫荧光、免疫印迹和电子显微镜。具体的终点将包括：脑血管体积、血脑屏障表面和通透性、脑毛细血管形态和转运蛋白的功能和表达。我们方法的新颖性源于定量和定性方法的结合。**结论：目前拨款申请的主要预期5年成果是：(I)形成接受与血脑屏障相关的技术培训的研究生，这在世界上只有几个实验室可用；(Ii)更好地了解载脂蛋白E对血脑屏障功能在大脑稳态中的作用。********

OVERVIEW: The aim of the present project is to decipher the role of the apolipoprotein E (ApoE) genotype on blood-brain barrier (BBB) functions, using animal models and series of complementary in vivo technical approaches.**BACKGROUND: The BBB controls the entry and exit of endogenous and exogenous compounds in the brain, thereby regulating brain homeostasis. Recent evidence indicates that brain function depends on ApoE genotype, possibly through alterations in functional and structural integrity of the BBB, but molecular mechanisms remain elusive.**RECENT PROGRESS: In the last years, we accumulated preliminary data suggesting that important BBB-related parameters are critically affected by the ApoE genotype in ApoE2, E3, and E4 mice.**SPECIFIC OBJECTIVES: BBB properties will be compared in mice specifically expressing human ApoE isoforms E2, E3, or E4. Technical approaches will combine in situ cerebral perfusion, immunofluorescence, Western immunoblotting and electron microscopy. Specific endpoints will include: cerebrovascular volume, BBB surface and permeability, brain capillary morphology and transporter function and expression. The novelty of our approach stems from the combination of quantitative and qualitative methodologies.**CONCLUSION: The main expected 5-year deliverables of the present grant application are (i) the formation of graduate students with training on techniques pertaining to the BBB, which are available in just a few laboratories in the world, and (ii) a better understanding of the role of ApoE on BBB function in brain homeostasis. ********