中国神经再生研究(英文版) ›› 2023, Vol. 18 ›› Issue (5): 1052-1056.doi: 10.4103/1673-5374.355760

• 原著:脑损伤修复保护与再生 • 上一篇    下一篇

整合素结合肽促进大鼠原代皮质血管内皮细胞的生长和血管样网络形成

  

  • 出版日期:2023-05-15 发布日期:2022-11-01

Integrin binding peptides facilitate growth and interconnected vascular-like network formation of rat primary cortical vascular endothelial cells in vitro

Ram Kuwar1, Xuejun Wen2, Ning Zhang3, Dong Sun1, *   

  1. 1Department of Anatomy and Neurobiology, Medical College of Virginia Campus, Virginia Commonwealth University, Richmond, VA, USA;  2Department of Chemical and Life Science Engineering, College of Engineering, Virginia Commonwealth University, Richmond, VA, USA;  3Department of Biomedical Engineering, College of Engineering, Virginia Commonwealth University, Richmond, VA, USA
  • Online:2023-05-15 Published:2022-11-01
  • Contact: Dong Sun, MD, PhD, dong.sun@vcuhealth.org or dsun@vcu.edu.
  • Supported by:
    This study was supported by NIH grant RO1 NS093985 (to DS, NZ, XW) and RO1 NS101955 (to DS). Confocal microscope images were performed at the VCU Microscopy Facility, supported, in part, by funding from NIH-NCI Cancer Center Support Grant P30 CA016059.

摘要: 大脑中的新生血管和血管生成是大脑正常发育和损伤后修复/再生的重要生理过程。整合素作为细胞表面黏附受体,参与细胞存活和生长,以及组织器官的分化和形成。实验使用整合素结合阵列平台来确定促进大鼠原代脑微血管内皮细胞(BMECs)的黏附、生长、发育和管状血管网的形成的重要整合素类型及其结合肽。BMECs是在出生后第7天从大鼠大脑中分离出来的。细胞在一个定制设计的整合素阵列系统中培养,该系统含有与脊椎动物细胞上普遍表达的16种整合素结合的短合成肽。培养7天后,对BMECs内皮细胞标记物Von Willibrand因子(VWF)和血小板内皮细胞粘附分子(PECAM-1)进行免疫染色。以BrdU法评估细胞增殖。在测试的16个整合素中,α5β1、αvβ5和αvβ8明显促进了ECs增殖。为了研究整合素结合肽在促进血管新生和血管生成方面的作用,将上述3种整合素的结合肽固定在我们定制设计的水凝胶上,在BMECs的3-D培养中加入血管内皮生长因子(VEGF)。 在为期7d的三维培养后,对培养物进行固定和处理,用VWF或PECAM-1对phalloidin进行双标染色。在与整合素结合肽共轭的水凝胶中进行三维培养时,BMECs形成了相互连接的血管状网络,其管腔清晰可辨,与体内脑微血管网络近似。利用新的整合素结合阵列系统,已经确定了BMECs上介导细胞粘附和生长的特定类型的整合素,然后使用结合肽对三维水凝胶培养系统进行功能化处理,使BMECs在三维培养中形成强大的生长和管腔化的微血管状网络。该技术可用于移植体或脑部病变的体外和体内血管化,以促进神经系统损伤后的脑组织再生。

https://orcid.org/0000-0002-3837-7319 (Dong Sun)

Abstract: Neovascularization and angiogenesis in the brain are important physiological processes for normal brain development and repair/regeneration following insults. Integrins are cell surface adhesion receptors mediating important function of cells such as survival, growth and development during tissue organization, differentiation and organogenesis. In this study, we used an integrin-binding array platform to identify the important types of integrins and their binding peptides that facilitate adhesion, growth, development, and vascular-like network formation of rat primary brain microvascular endothelial cells. Brain microvascular endothelial cells were isolated from rat brain on post-natal day 7. Cells were cultured in a custom-designed integrin array system containing short synthetic peptides binding to 16 types of integrins commonly expressed on cells in vertebrates. After 7 days of culture, the brain microvascular endothelial cells were processed for immunostaining with markers for endothelial cells including von Willibrand factor and platelet endothelial cell adhesion molecule. 5-Bromo-2′-dexoyuridine was added to the culture at 48 hours prior to fixation to assess cell proliferation. Among 16 integrins tested, we found that α5β1, αvβ5 and αvβ8 greatly promoted proliferation of endothelial cells in culture. To investigate the effect of integrin-binding peptides in promoting neovascularization and angiogenesis, the binding peptides to the above three types of integrins were immobilized to our custom-designed hydrogel in three-dimensional (3D) culture of brain microvascular endothelial cells with the addition of vascular endothelial growth factor. Following a 7-day 3D culture, the culture was fixed and processed for double labeling of phalloidin with von Willibrand factor or platelet endothelial cell adhesion molecule and assessed under confocal microscopy. In the 3D culture in hydrogels conjugated with the integrin-binding peptide, brain microvascular endothelial cells formed interconnected vascular-like network with clearly discernable lumens, which is reminiscent of brain microvascular network in vivo. With the novel integrin-binding array system, we identified the specific types of integrins on brain microvascular endothelial cells that mediate cell adhesion and growth followed by functionalizing a 3D hydrogel culture system using the binding peptides that specifically bind to the identified integrins, leading to robust growth and lumenized microvascular-like network formation of brain microvascular endothelial cells in 3D culture. This technology can be used for in vitro and in vivo vascularization of transplants or brain lesions to promote brain tissue regeneration following neurological insults.  

Key words: 3D culture, angiogenesis, brain microvascular endothelial cells, hydrogel, integrins, platelet endothelial cell adhesion molecule (PECAM-1), vascular endothelial growth factor (VEGF), vascularization