The impact of the physical microenvironment on trophoblast function

胎盘是一个重要的器官，在怀孕期间发育，使胎儿获得营养和排除废物。胎盘既是看门人又是内分泌器官；这两项功能对健康怀孕至关重要。然而，由于在整个怀孕阶段获得组织的伦理问题以及缺乏控制水平和生理相关性的体外或离体系统的不良，胎盘在系统扰动后的行为尚不清楚。在初步研究中，我们已经成功地制作了一个体外微流控胎盘模型，该模型允许在天然蛋白凝胶中培养三种不同的细胞类型（滋养细胞、成纤维细胞和内皮细胞）。微流体通道将剪切应力纳入模型，三细胞培养允许细胞间通信，这两者都被证明对生理相关的滋养细胞表型至关重要。细胞可以在取自人胎盘的天然基质上培养：(1)容易，(2)平行，(3)严格控制，(4)不需要微流体方面的专业技术。该模型可以很容易地更新，以研究健康或失调胎盘的许多机制和基本特性。妊娠期间可引起并发症的一种疾病，子痫前期（PE），与子宫壁有限重塑引起的胎盘破裂有关；这一过程对于确保胎盘组织的健康、适当的氧气浓度和胎盘内适当的剪切应力至关重要。由于子宫重构缺失，胎盘细胞外基质（ECM）因纤维化而硬化，氧张力降低，剪应力增加。我们假设胎盘中的这些物理微环境线索导致滋养细胞功能中断，这可以在我们的新型微流体胎盘模型中进行机械检查。在目标1中，我们将改变我们的微流体装置，以测试ECM失调如何改变滋养细胞功能。我们将从i型胶原和人胎盘来源的ECM中制作健康或致病硬度的间质层。胎盘来源的ECM将使我们能够测试胎盘ECM的完整环境如何影响滋养细胞功能，而胶原- i ECM将允许更严格地控制环境。在目的2中，我们将测试氧张力和剪应力对滋养层功能的密切关系。设备将在健康或致病的氧张力和剪切应力下培养，以阐明它们的刺激是否协同。这些研究将证明我们的系统能够轻松地控制系统的微物理特性，以阐明胎盘多细胞模型的机制特性。

The placenta is a critical organ that develops during pregnancy to allow the fetus to obtain nutrients and remove waste. The placenta acts as both a gatekeeper and an endocrine organ; two functions which are vital for a healthy pregnancy. However, how the placenta acts after perturbations of the system is not well known due to ethical concerns regarding obtaining tissue throughout all stages of pregnancy and poor in vitro or ex vivo systems that lack the level of control and physiological relevance needed. In preliminary studies, we have successfully made an in vitro microfluidic placenta model that allows for culture of three different cell types (trophoblast, fibroblasts, and endothelial cells) within natural protein gels. Microfluidic channels incorporate shear stress into the model and the tri-cell culture allows for cell-cell communication which have both been shown to be vital for physiologically relevant trophoblast phenotype. Cells can be cultured on natural substrates derived from human placenta with (1) ease, (2) in parallel, (3) with tight control, and (4) without the need for technical expertise in microfluidics. The model can easily be updated to study many mechanistic and fundamental properties of the healthy or dysregulated placenta. One disease that can cause complications during pregnancy, preeclampsia (PE), is associated with disrupted placentation from limited remodeling of the uterine wall; a process vital to ensure healthy placental tissue, proper oxygen concentration, and appropriate amount of shear stress within the placenta. Due to the lack of uterine remodeling, placental extracellular matrix (ECM) is stiffened via fibrosis, oxygen tension is lowered, and shear stress is increased. We hypothesize that these physical microenvironmental cues within the placenta cause disrupted trophoblast function that can be mechanistically examined in our novel microfluidic placenta model. In Aim 1 we will alter our microfluidic device in order to test how ECM dysregulation alters trophoblast function. We will make stromal layers of healthy or pathogenic stiffnesses from both collagen-I and human placenta derived ECM. Placental derived ECM will enable us to test how the full milieu of the placenta ECM impacts trophoblast function, while the collagen-I ECM will allow for tighter control of the environment. In Aim 2 we will test the closely tied relationship between oxygen tension and shear stress on trophoblast function. Devices will be cultured at healthy or pathogenic oxygen tension and shear stress to elucidate if their stimuli are synergistic. These studies will demonstrate the ease of our system in being able to control the microphysical properties of the system for elucidation of mechanistic properties of multi-cell models of the placenta.