Cowdin Mitzy A, Pramanik Tuli, Mohr-Allen Shelby R, Fu Yuting, Mills Austin, Spurgin Stephen B, Varner Victor D, Davis George E, Cleaver Ondine
Department of Molecular Biology, Center for Regenerative Science and Medicine (M.A.C., T.P., A.M., O.C.), University of Texas Southwestern Medical Center, Dallas.
Department of Bioengineering, University of Texas at Dallas, Richardson (S.R.M.-A., V.D.V.).
Arterioscler Thromb Vasc Biol. 2025 Sep;45(9):1521-1542. doi: 10.1161/ATVBAHA.124.322258. Epub 2025 Jun 12.
Mechanical cues exerted by shear stress from blood flow remodel an initial vascular plexus into a ramifying array of large and small vessels. Hemodynamic forces trigger changes in endothelial cell (EC) gene expression and dynamic alterations in cell shape and adhesion. The objective of this study is to elucidate the role of the Lats (large tumor suppressor) 1 and Lats2 (Lats1/2) Hippo pathway kinases in EC transducing of hemodynamic signals as vessels form.
Lats1/2 were genetically deleted in murine ECs () and developing vessels were evaluated using immunofluorescence. Primary human pulmonary artery ECs were used to model endothelial response to blood flow and Lats1/2 depletion was achieved via siRNA treatment. EC junctions, cytoskeletal rearrangements, cell shape, and polarization were assessed using immunofluorescence. mRNA expression analyses and Western blotting were performed to understand changes in the response of cultured ECs to shear stress.
We report a critical requirement for Lats1/2 in adapting to blood flow during vascular development. When Lats1/2 are genetically deleted in ECs, embryos develop severe defects in blood vessel formation, which lead to embryonic lethality by embryonic day 11.5. Vessel patterning and circulation initiate properly; however, remodeling of the initial vascular plexus fails due to lumen collapse. Lats1/2 depletion in cultured ECs leads to failed polarization, elongation, and VEcad (vascular endothelial cadherin 5 or Cdh5) junctional maturation under flow. Finally, YAP (Yes-associated protein)/TAZ (transcriptional coactivator with PDZ-binding motif) codepletion in Lats1/2 depleted conditions leads to a partial rescue of phenotypes in vivo and in vitro.
Our results suggest that Lats1/2 deficient cells no longer respond to laminar shear stress, in vivo and in vitro. This work identifies Lats1 and Lats2 as critical transducers of biomechanical cues during early blood vessel remodeling. This study provides new targets for treating vascular diseases and new directions for efforts to generate vascularized tissues for replacement therapies.
血流产生的剪切应力所施加的机械信号将最初的血管丛重塑为大小血管分支排列。血流动力学力引发内皮细胞（EC）基因表达的变化以及细胞形状和黏附的动态改变。本研究的目的是阐明大肿瘤抑制因子（Lats）1和Lats2（Lats1/2）Hippo通路激酶在血管形成过程中内皮细胞转导血流动力学信号中的作用。
在小鼠内皮细胞中通过基因敲除Lats1/2，并使用免疫荧光评估发育中的血管。使用原代人肺动脉内皮细胞模拟内皮细胞对血流的反应，并通过小干扰RNA（siRNA）处理实现Lats1/2缺失。使用免疫荧光评估内皮细胞连接、细胞骨架重排、细胞形状和极化。进行mRNA表达分析和蛋白质免疫印迹以了解培养的内皮细胞对剪切应力反应的变化。
我们报告了Lats1/2在血管发育过程中适应血流的关键需求。当在内皮细胞中通过基因敲除Lats1/2时，胚胎在血管形成中出现严重缺陷，导致在胚胎第11.5天胚胎致死。血管模式和循环正常启动；然而，由于管腔塌陷，最初的血管丛重塑失败。培养的内皮细胞中Lats1/2缺失导致在流动条件下极化、伸长和血管内皮钙黏蛋白5（VEcad或Cdh5）连接成熟失败。最后，在Lats1/2缺失条件下Yes相关蛋白（YAP）/具有PDZ结合基序的转录共激活因子（TAZ）共缺失导致体内和体外表型部分挽救。
我们的结果表明，Lats1/2缺陷细胞在体内和体外不再对层流剪切应力作出反应。这项工作确定Lats1和Lats2是早期血管重塑过程中生物力学信号的关键转导因子。本研究为治疗血管疾病提供了新靶点，并为努力生成用于替代疗法的血管化组织提供了新方向。
