Microvascular endothelial cell heterogeneity in the central nervous system

微血管内皮异质性的问题极大地影响了健康和糖尿病患者的血管功能。 疾病，并可能严重复杂化使用基于组织培养的模型来研究内皮细胞 行为然而，尽管这一主题已经在外周血管床中进行了相当深入的探索， 令人惊讶的是，很少有人关注中枢神经系统（CNS）的微血管轴。 尽管如此，描述特定基因的不相关报告仍然有力地表明， 内皮基因表达可能存在于节段水平（即，在小动脉，毛细血管和 小静脉）以及CNS的区域水平，并且接近或超过在外周中发现的水平。 考虑到微血管网络在形成血脑屏障和血脑屏障方面的卓越作用， 脊髓屏障，并在炎症，感染，退行性病变的显着微血管参与 和创伤性条件的中枢神经系统，这是至关重要的，有一个系统和详细的评估，这是 临床重要问题。在微血管组织上进行这种分析更重要 因为内皮细胞基因表达非常容易受到环境调节。因此，委员会认为， 本文的具体研究目的是：1）验证和优化耦合激光捕获的方法 脑微血管内皮细胞的显微切割（LCM），通过DMA进行整体基因表达谱分析 微阵列分析。这将包括通过最大限度地提高成绩单的百分比来证明可行性 仅在毛细管中检测（P调用率），并通过鉴定技术和 微阵列数据中方差的生物学来源; 2）使用LCM/微阵列方法比较 毛细血管、小静脉和小动脉内皮细胞的整体基因表达谱。R21 选择的格式是专门为探索性项目设计的，可能涉及相当大的风险，但 导致可能对研究领域产生重大影响的新技术的发展。在这 考虑到，这里获得的结果将为评估神经血管的区域基因表达奠定基础。 在这两种情况下，沿着CNS微血管树沿着细胞（即内皮细胞和密切相关的神经细胞）， 健康和疾病。反过来，这些研究将使制定更精确的内皮模型，以研究 脑微血管生理和病理生理过程的分子基础。

The issue of microvascular endothelial heterogeneity greatly impacts vascular function in both health and disease, and potentially severly complicates the use of tissue culture-based models to study endothelial behavior. Yet, despite this topic having been explored in considerable depth in peripheral vascular beds, surprisingly little attention has yet been focused on the microvascular axis of central nervous system (CNS). Unrelated reports describing particular genes have, nonetheless, provocatively suggested that a diversity in endothelial gene expression may exist at the segmental level (i.e., between arterioles, capillaries and venules) as well as the regional level of the CNS, and approximate or surpass that found in the periphery. Given the preeminance of the microvascular network in forming both the blood-brain barrier and blood- spinal cord barrier, and the significant microvascular involvement in inflammatory, infectious, degenerative and traumatic conditions of the CNS, it is critical that there be a systematic and detailed evaluation of this cliinically important issue. It is of further importance that such analysis be performed on microvascular tissue in situ," as endothelial cell gene expression is exquisitely prone to environmental modulation. Accordingly, we propose the following Specific Aims: 1) To validate and optimize the approach of coupling laser capture microdissection (LCM) of brain microvascular endothelial cells, with global gene expression profiling byDMA microarray analysis. This will include demonstrating feasibility, by maximizing the percentage of transcripts detected (P call rate) in capillaries only, and establishing reproducibility, by identifying both technical and biological sources of variance in microarray data; and 2) To use the LCM/microarray approach to compare the global gene expression profiles of endothelial cells from capillaries, venules and arterioles. The R21 format chosen is specifically designed for projects that are exploratory and may involve considerable risk, but lead to the development of novel techniques that could have major impact on a field of research. In this regard, results obtained here will set the stage for evaluating regional gene expression by the neurovascular unit (i.e,endothelial cells and intimately associated neural cells) along the CNS microvascular tree in both health and disease. In turn, these studies will enable formulation of more precise endothelial models to study the molecular basis of physiological and pathophysiological processes of the cerebral microvasculature.