Perottoni Simone, Neto Nuno G B, Di Nitto Cesare, Dmitriev Ruslan I, Raimondi Manuela Teresa, Monaghan Michael G
Department of Chemistry, Materials and Chemical Engineering "Giulio Natta", Politecnico di Milano, Piazza Leonardo da Vinci, 32 - 20133 Milan, Italy.
Lab Chip. 2021 Apr 7;21(7):1395-1408. doi: 10.1039/d0lc01034k. Epub 2021 Feb 19.
The stem cell niche at the perivascular space in human tissue plays a pivotal role in dictating the overall fate of stem cells within it. Mesenchymal stem cells (MSCs) in particular, experience influential microenvironmental conditions, which induce specific metabolic profiles that affect processes of cell differentiation and dysregulation of the immunomodulatory function. Reports focusing specifically on the metabolic status of MSCs under the effect of pathophysiological stimuli - in terms of flow velocities, shear stresses or oxygen tension - do not model heterogeneous gradients, highlighting the need for more advanced models reproducing the metabolic niche. Organ-on-a-chip technology offers the most advanced tools for stem cell niche modelling thus allowing for controlled dynamic culture conditions while profiling tuneable oxygen tension gradients. However, current systems for live cell detection of metabolic activity inside microfluidic devices require the integration of microsensors. The presence of such microsensors poses the potential to alter microfluidics and their resolution does not enable intracellular measurements but rather a global representation concerning cellular metabolism. Here, we present a metabolic toolbox coupling a miniaturised in vitro system for human-MSCs dynamic culture, which mimics microenvironmental conditions of the perivascular niche, with high-resolution imaging of cell metabolism. Using fluorescence lifetime imaging microscopy (FLIM) we monitor the spatial metabolic machinery and correlate it with experimentally validated intracellular oxygen concentration after designing the oxygen tension decay along the fluidic chamber by in silico models prediction. Our platform allows the metabolic regulation of MSCs, mimicking the physiological niche in space and time, and its real-time monitoring representing a functional tool for modelling perivascular niches, relevant diseases and metabolic-related uptake of pharmaceuticals.
人体组织中血管周围空间的干细胞生态位在决定其中干细胞的整体命运方面起着关键作用。特别是间充质干细胞（MSC），会经历有影响力的微环境条件，这些条件会诱导特定的代谢谱，从而影响细胞分化过程和免疫调节功能的失调。专门关注病理生理刺激（如流速、剪切应力或氧张力）作用下MSC代谢状态的报告并未模拟异质梯度，这凸显了需要更先进的模型来重现代谢生态位。芯片器官技术为干细胞生态位建模提供了最先进的工具，从而在描绘可调节的氧张力梯度时允许进行可控的动态培养条件。然而，目前用于微流控设备内代谢活性活细胞检测的系统需要集成微传感器。这种微传感器的存在有可能改变微流控，并且其分辨率无法实现细胞内测量，而只能提供有关细胞代谢的整体表征。在这里，我们展示了一个代谢工具箱，它将用于人MSC动态培养的小型体外系统与细胞代谢的高分辨率成像相结合，该体外系统模拟了血管周围生态位的微环境条件。通过计算机模型预测设计沿流体腔室的氧张力衰减后，我们使用荧光寿命成像显微镜（FLIM）监测空间代谢机制，并将其与经过实验验证的细胞内氧浓度相关联。我们的平台允许对MSC进行代谢调节，在空间和时间上模拟生理生态位，并对其进行实时监测，这代表了一种用于模拟血管周围生态位、相关疾病和药物代谢相关摄取的功能工具。
