Department of Biomedical Engineering, Tulane University, New Orleans, LA, USA.
J. Crayton Pruitt Family Department of Biomedical Engineering, University of Florida, Gainesville, FL, USA.
Microcirculation. 2020 Feb;27(2):e12595. doi: 10.1111/micc.12595. Epub 2019 Nov 8.
Emerging areas of vascular biology focus on lymphatic/blood vessel mispatterning and the regulation of endothelial cell identity. However, a fundamental question remains unanswered: Can lymphatic vessels become blood vessels in adult tissues? Leveraging a novel tissue culture model, the objective of this study was to track lymphatic endothelial cell fate over the time course of adult microvascular network remodeling.
Cultured adult Wistar rat mesenteric tissues were labeled with BSI-lectin and time-lapse images were captured over five days of serum-stimulated remodeling. Additionally, rat mesenteric tissues on day 0 and day 3 and 5 post-culture were labeled for PECAM + LYVE-1 or PECAM + podoplanin.
Cultured networks were characterized by increases in blood capillary sprouting, lymphatic sprouting, and the number of lymphatic/blood vessel connections. Comparison of images from the same network regions identified incorporation of lymphatic vessels into blood vessels. Mosaic lymphatic/blood vessels contained lymphatic marker positive and negative endothelial cells.
Our results reveal the ability for lymphatic vessels to transition into blood vessels in adult microvascular networks and discover a new paradigm for investigating lymphatic/blood endothelial cell dynamics during microvascular remodeling.
血管生物学的新兴领域关注淋巴管/血管的错位以及内皮细胞特性的调控。然而，一个基本问题仍未得到解答：在成人组织中，淋巴管能否转变为血管？本研究利用一种新的组织培养模型，旨在追踪淋巴管内皮细胞在成人微血管网络重塑过程中的命运。
用 BSI-lectin 标记培养的成年 Wistar 大鼠肠系膜组织，并在血清刺激重塑的五天内拍摄延时图像。此外，在培养的第 0 天、第 3 天和第 5 天对大鼠肠系膜组织进行 PECAM+LYVE-1 或 PECAM+podoplanin 标记。
培养的网络以毛细血管发芽、淋巴管发芽和淋巴管/血管连接数量的增加为特征。对同一网络区域的图像进行比较，发现淋巴管被整合到血管中。镶嵌性的淋巴管/血管包含阳性和阴性淋巴管内皮细胞。
我们的结果揭示了成人微血管网络中淋巴管向血管转化的能力，并发现了一种新的范式，用于研究微血管重塑过程中的淋巴管/血管内皮细胞动力学。
