Dunster Joanne L, Unsworth Amanda J, Bye Alexander P, Haining Elizabeth J, Sowa Marcin A, Di Ying, Sage Tanya, Pallini Chiara, Pike Jeremy A, Hardy Alexander T, Nieswandt Bernhard, García Ángel, Watson Steve P, Poulter Natalie S, Gibbins Jonathan M, Pollitt Alice Y
Institute for Cardiovascular and Metabolic Research (ICMR), School of Biological Sciences, University of Reading, Reading, UK.
Department of Life Sciences, School of Science and Engineering, Manchester Metropolitan University, Manchester, UK.
J Thromb Haemost. 2020 Feb;18(2):485-496. doi: 10.1111/jth.14673. Epub 2019 Dec 6.
Accurate protein quantification is a vital prerequisite for generating meaningful predictions when using systems biology approaches, a method that is increasingly being used to unravel the complexities of subcellular interactions and as part of the drug discovery process. Quantitative proteomics, flow cytometry, and western blotting have been extensively used to define human platelet protein copy numbers, yet for mouse platelets, a model widely used for platelet research, evidence is largely limited to a single proteomic dataset in which the total amount of proteins was generally comparatively higher than those found in human platelets.
To investigate the functional implications of discrepancies between levels of mouse and human proteins in the glycoprotein VI (GPVI) signalling pathway using a systems pharmacology model of GPVI.
The protein copy number of mouse platelet receptors was determined using flow cytometry. The Virtual Platelet, a mathematical model of GPVI signalling, was used to determine the consequences of protein copy number differences observed between human and mouse platelets.
Despite the small size of mouse platelets compared to human platelets they possessed a greater density of surface receptors alongside a higher concentration of intracellular signalling proteins. Surprisingly the predicted temporal profile of Syk activity was similar in both species with predictions supported experimentally. Super resolution microscopy demonstrates that the spatial distribution of Syk is similar between species, suggesting that the spatial distribution of receptors and signalling molecules in activated platelets, rather than their copy number, is important for signalling pathway regulation.
在使用系统生物学方法时，准确的蛋白质定量是做出有意义预测的重要前提条件，系统生物学方法越来越多地用于揭示亚细胞相互作用的复杂性，并作为药物发现过程的一部分。定量蛋白质组学、流式细胞术和蛋白质印迹法已被广泛用于确定人类血小板的蛋白质拷贝数，但对于广泛用于血小板研究的小鼠血小板模型，证据主要限于单个蛋白质组数据集，其中蛋白质总量通常比人类血小板中的蛋白质总量高。
使用糖蛋白VI（GPVI）的系统药理学模型研究小鼠和人类蛋白质在GPVI信号通路中水平差异的功能影响。
使用流式细胞术测定小鼠血小板受体的蛋白质拷贝数。GPVI信号的数学模型“虚拟血小板”用于确定在人类和小鼠血小板之间观察到的蛋白质拷贝数差异的后果。
尽管与人类血小板相比，小鼠血小板体积较小，但它们具有更高密度的表面受体以及更高浓度的细胞内信号蛋白。令人惊讶的是，两种物种中Syk活性的预测时间概况相似，预测结果得到了实验支持。超分辨率显微镜显示，物种间Syk的空间分布相似，这表明活化血小板中受体和信号分子的空间分布而非其拷贝数对信号通路调节很重要。
