Department of Biomedicine, University Hospital Basel & University Basel, Hebelstr. 20, 4031, Basel, Switzerland.
Department of Ophthalmology, University Hospital Basel & University Basel, Hebelstr. 20, 4031, Basel, Switzerland.
Fluids Barriers CNS. 2019 Jun 13;16(1):17. doi: 10.1186/s12987-019-0137-6.
Altered flow of cerebrospinal fluid (CSF) within the subarachnoid space (SAS) is connected to brain, but also optic nerve degenerative diseases. To overcome the lack of suitable in vitro models that faithfully recapitulate the intricate three-dimensional architecture, complex cellular interactions, and fluid dynamics within the SAS, we have developed a perfusion bioreactor-based 3D in vitro model using primary human meningothelial cells (MECs) to generate meningeal tissue constructs. We ultimately employed this model to evaluate the impact of impaired CSF flow as evidenced during optic nerve compartment syndrome on the transcriptomic landscape of MECs.
Primary human meningothelial cells (phMECs) were seeded and cultured on collagen scaffolds in a perfusion bioreactor to generate engineered meningeal tissue constructs. Engineered constructs were compared to human SAS and assessed for specific cell-cell interaction markers as well as for extracellular matrix proteins found in human meninges. Using the established model, meningeal tissue constructs were exposed to physiological and pathophysiological flow conditions simulating the impaired CSF flow associated with optic nerve compartment syndrome and RNA sequencing was performed.
Engineered constructs displayed similar microarchitecture compared to human SAS with regards to pore size, geometry as well as interconnectivity. They stained positively for specific cell-cell interaction markers indicative of a functional meningeal tissue, as well as extracellular matrix proteins found in human meninges. Analysis by RNA sequencing revealed altered expression of genes associated with extracellular matrix remodeling, endo-lysosomal processing, and mitochondrial energy metabolism under pathophysiological flow conditions.
Alterations of these biological processes may not only interfere with critical MEC functions impacting CSF and hence optic nerve homeostasis, but may likely alter SAS structure, thereby further impeding cerebrospinal fluid flow. Future studies based on the established 3D model will lead to new insights into the role of MECs in the pathogenesis of optic nerve but also brain degenerative diseases.
蛛网膜下腔（SAS）内脑脊液（CSF）流动的改变与大脑有关，但也与视神经退行性疾病有关。为了克服缺乏能够真实再现 SAS 内复杂三维结构、复杂细胞相互作用和流体动力学的合适体外模型的问题，我们开发了一种基于灌注生物反应器的 3D 体外模型，使用原代人脑脊膜细胞（MEC）生成脑膜组织构建体。我们最终使用该模型评估了视神经间隙综合征期间 CSF 流动受损对 MEC 转录组景观的影响。
将原代人脑脊膜细胞（phMEC）接种并在灌注生物反应器中的胶原支架上培养，以生成工程脑膜组织构建体。对工程构建体进行比较，以评估其与人类 SAS 的特定细胞-细胞相互作用标志物以及人类脑膜中发现的细胞外基质蛋白。使用已建立的模型，将脑膜组织构建体暴露于模拟与视神经间隙综合征相关的 CSF 流动受损的生理和病理生理流动条件下，并进行 RNA 测序。
与人类 SAS 相比，工程构建体在孔径、几何形状和连通性方面具有相似的微观结构。它们对指示功能性脑膜组织的特定细胞-细胞相互作用标志物以及人类脑膜中发现的细胞外基质蛋白呈阳性染色。RNA 测序分析显示，在病理生理流动条件下，与细胞外基质重塑、内溶酶体加工和线粒体能量代谢相关的基因表达发生改变。
这些生物学过程的改变不仅可能干扰影响 CSF 进而影响视神经稳态的关键 MEC 功能，而且可能改变 SAS 结构，从而进一步阻碍 CSF 流动。基于已建立的 3D 模型的未来研究将深入了解 MEC 在视神经但也在脑退行性疾病发病机制中的作用。
