人内皮细胞中血管内皮生长因子受体1(VEGFR1)、血管内皮生长因子受体2(VEGFR2)和神经纤毛蛋白1(NRP1)的转运动力学
Trafficking dynamics of VEGFR1, VEGFR2, and NRP1 in human endothelial cells.
作者信息
Sarabipour Sarvenaz, Kinghorn Karina, Quigley Kaitlyn M, Kovacs-Kasa Anita, Annex Brian H, Bautch Victoria L, Mac Gabhann Feilim
机构信息
Institute for Computational Medicine and Department of Biomedical Engineering, Johns Hopkins University, Baltimore, Maryland, United States of America.
Curriculum in Cell Biology and Physiology, University of North Carolina, Chapel Hill, North Carolina, United States of America.
出版信息
PLoS Comput Biol. 2024 Feb 7;20(2):e1011798. doi: 10.1371/journal.pcbi.1011798. eCollection 2024 Feb.
The vascular endothelial growth factor (VEGF) family of cytokines are key drivers of blood vessel growth and remodeling. These ligands act via multiple VEGF receptors (VEGFR) and co-receptors such as Neuropilin (NRP) expressed on endothelial cells. These membrane-associated receptors are not solely expressed on the cell surface, they move between the surface and intracellular locations, where they can function differently. The location of the receptor alters its ability to 'see' (access and bind to) its ligands, which regulates receptor activation; location also alters receptor exposure to subcellularly localized phosphatases, which regulates its deactivation. Thus, receptors in different subcellular locations initiate different signaling, both in terms of quantity and quality. Similarly, the local levels of co-expression of other receptors alters competition for ligands. Subcellular localization is controlled by intracellular trafficking processes, which thus control VEGFR activity; therefore, to understand VEGFR activity, we must understand receptor trafficking. Here, for the first time, we simultaneously quantify the trafficking of VEGFR1, VEGFR2, and NRP1 on the same cells-specifically human umbilical vein endothelial cells (HUVECs). We build a computational model describing the expression, interaction, and trafficking of these receptors, and use it to simulate cell culture experiments. We use new quantitative experimental data to parameterize the model, which then provides mechanistic insight into the trafficking and localization of this receptor network. We show that VEGFR2 and NRP1 trafficking is not the same on HUVECs as on non-human ECs; and we show that VEGFR1 trafficking is not the same as VEGFR2 trafficking, but rather is faster in both internalization and recycling. As a consequence, the VEGF receptors are not evenly distributed between the cell surface and intracellular locations, with a very low percentage of VEGFR1 being on the cell surface, and high levels of NRP1 on the cell surface. Our findings have implications both for the sensing of extracellular ligands and for the composition of signaling complexes at the cell surface versus inside the cell.
细胞因子血管内皮生长因子(VEGF)家族是血管生长和重塑的关键驱动因素。这些配体通过多种VEGF受体(VEGFR)以及内皮细胞上表达的共受体(如神经纤毛蛋白(NRP))发挥作用。这些膜相关受体并非仅表达于细胞表面,它们会在细胞表面和细胞内位置之间移动,在不同位置其功能也有所不同。受体的位置会改变其“看见”(接近并结合)配体的能力,从而调节受体激活;位置的改变还会影响受体与亚细胞定位的磷酸酶的接触,进而调节其失活。因此,处于不同亚细胞位置的受体在数量和质量上都会引发不同的信号传导。同样,其他受体的共表达局部水平会改变对配体的竞争。亚细胞定位由细胞内运输过程控制,进而控制VEGFR活性;所以,要理解VEGFR活性,我们必须了解受体运输。在此,我们首次同时定量了同一细胞(具体为人脐静脉内皮细胞(HUVECs))上VEGFR1、VEGFR2和NRP1的运输情况。我们构建了一个计算模型,描述这些受体的表达、相互作用和运输,并利用该模型模拟细胞培养实验。我们使用新的定量实验数据对模型进行参数化,进而为该受体网络的运输和定位提供机制性见解。我们发现,HUVECs上VEGFR2和NRP1的运输情况与非人类内皮细胞不同;并且我们还发现VEGFR1的运输与VEGFR2不同,其内化和再循环速度更快。因此,VEGF受体在细胞表面和细胞内位置之间分布不均,VEGFR1在细胞表面的比例非常低,而NRP1在细胞表面的水平较高。我们的研究结果对于细胞外配体的感知以及细胞表面与细胞内信号复合物的组成均具有重要意义。