The role of ApoE genotype on blood-brain barrier functions

概述：本项目的目的是使用动物模型和一系列互补的体内技术方法来破译载脂蛋白E（ApoE）基因型对血脑屏障（BBB）功能的作用。 背景：血脑屏障控制内源性和外源性物质进入和排出脑内，从而调节脑内环境的稳定。最近的证据表明，脑功能取决于ApoE基因型，可能通过改变BBB的功能和结构完整性，但分子机制仍然难以捉摸。 最新进展：在过去的几年中，我们积累的初步数据表明，重要的BBB相关参数是严重影响ApoE基因型在ApoE 2，E3和E4小鼠。 特异性抑制剂：将在特异性表达人ApoE亚型E2、E3或E4的小鼠中比较BBB特性。技术方法将结合联合收割机原位脑灌注，免疫荧光，Western免疫印迹和电子显微镜。具体终点包括：脑血管体积、BBB表面和通透性、脑毛细血管形态和转运蛋白功能和表达。我们的方法的新奇源于定量和定性方法的结合。 结论：本资助申请的主要预期5年交付成果是（i）培养研究生，接受有关BBB技术的培训，这些技术在世界上只有少数实验室可用，以及（ii）更好地了解ApoE对脑内稳态中BBB功能的作用。

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.