Wnt signaling mediates acquisition of blood-brain barrier properties in naïve endothelium derived from human pluripotent stem cells.
Wnt signaling mediates acquisition of blood-brain barrier properties in naïve endothelium derived from human pluripotent stem cells.
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Wnt信号传导介导人多能干细胞来源的幼稚内皮细胞获得血脑屏障特性。
DOI：
10.7554/elife.70992
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发表时间：
2021-11-10
期刊：
影响因子：
7.7
通讯作者：
Shusta EV
中科院分区：
文献类型：
--
作者：
Gastfriend BD;Nishihara H;Canfield SG;Foreman KL;Engelhardt B;Palecek SP;Shusta EV
中枢神经系统（CNS）中的内皮细胞（ECs）在外界信号作用下获得其特有的血脑屏障（BBB）特性，其中Wnt/β -连环蛋白信号通路协调该过程的多个方面。我们对中枢神经系统内皮细胞发育的认识在很大程度上是通过动物模型取得的，而人类多能干细胞（hPSCs）为在体外人类系统中研究血脑屏障发育提供了机会。在此，我们表明在人类多能干细胞衍生的原始内皮祖细胞中激活Wnt信号通路（而非在成熟内皮细胞中），可促使其强烈获得典型的血脑屏障表型，包括葡萄糖转运蛋白 - 1（GLUT - 1）的表达、紧密连接蛋白 - 5（claudin - 5）增加、质膜微囊相关蛋白（PLVAP）减少以及通透性降低。RNA测序揭示了一种类似于具有中枢神经系统特征的内皮细胞的转录组图谱，包括Wnt上调的淋巴增强因子1（LEF1）、含犰狳重复序列的蛋白下调因子1（APCDD1）和锌指蛋白3（ZIC3）的表达。总之，我们的工作明确了Wnt激活在原始内皮细胞中的作用，并建立了一种改进的基于人类多能干细胞的模型，用于探究中枢神经系统屏障发生。
血管内部的细胞被称为内皮细胞。在脑血管中，这些细胞形成一种被称为“血脑屏障”的结构，它允许营养物质从血液进入大脑，同时防止像毒素这样的有害物质穿过。血脑屏障的缺陷可能导致神经系统疾病，而且血脑屏障也会限制药物进入大脑，使得某些疾病难以治疗。了解形成血脑屏障的内皮细胞是如何发育的，可能为神经系统疾病的新疗法提供思路。
在胚胎发育过程中，内皮细胞由干细胞发育而来。它们也可以在实验室中由人类多能干细胞（hPSCs）产生，人类多能干细胞是一种能够产生更多与其自身相似的细胞，或者分化为身体内任何细胞类型的细胞。科学家可以用特定分子处理人类多能干细胞，使其分化为内皮细胞，或者改变它们的特性。这使得研究人员能够监测不同类型内皮细胞的形成过程。
血脑屏障处的内皮细胞是其中一种类型。在其发育过程中，这些细胞获得了独特的特征，包括产生被称为葡萄糖转运蛋白 - 1（GLUT - 1）、紧密连接蛋白 - 5（claudin - 5）和脂质清道夫受体（LSR）的蛋白质。葡萄糖转运蛋白 - 1将葡萄糖转运穿过内皮细胞的细胞膜，而紧密连接蛋白 - 5和脂质清道夫受体将相邻细胞紧密连接在一起，防止分子通过细胞间的空隙渗漏到大脑中。在小鼠内皮细胞中，一种被称为Wnt的信号蛋白负责启动编码这些蛋白质的基因。但是Wnt信号对人类内皮细胞有何影响呢？
加斯特弗里德等人探究了Wnt信号在实验室中从人类多能干细胞分化而来的人类内皮细胞上的作用。他们发现当Wnt信号被激活时，人类内皮细胞会形成独特的血脑屏障特征，产生葡萄糖转运蛋白 - 1（GLUT - 1）、紧密连接蛋白 - 5（claudin - 5）和脂质清道夫受体（LSR）。加斯特弗里德等人还发现人类内皮细胞在其发育早期对Wnt信号更敏感。此外，他们还确定了当Wnt信号被触发时在人类内皮细胞中被激活的基因。
这些发现为形成人类血脑屏障的内皮细胞的发育和特征提供了见解。这些结果是朝着更好地理解该结构在人类中如何运作迈出的第一步。这一信息也可能使研究人员能够开发将药物递送至大脑的新方法。
Endothelial cells (ECs) in the central nervous system (CNS) acquire their specialized blood–brain barrier (BBB) properties in response to extrinsic signals, with Wnt/β-catenin signaling coordinating multiple aspects of this process. Our knowledge of CNS EC development has been advanced largely by animal models, and human pluripotent stem cells (hPSCs) offer the opportunity to examine BBB development in an in vitro human system. Here, we show that activation of Wnt signaling in hPSC-derived naïve endothelial progenitors, but not in matured ECs, leads to robust acquisition of canonical BBB phenotypes including expression of GLUT-1, increased claudin-5, decreased PLVAP, and decreased permeability. RNA-seq revealed a transcriptome profile resembling ECs with CNS-like characteristics, including Wnt-upregulated expression of LEF1, APCDD1, and ZIC3. Together, our work defines effects of Wnt activation in naïve ECs and establishes an improved hPSC-based model for interrogation of CNS barriergenesis. The cells that line the inside of blood vessels are called endothelial cells. In the blood vessels of the brain, these cells form a structure called the ‘blood-brain barrier’, which allows nutrients to pass from the blood into the brain, while at the same time preventing harmful substances like toxins from crossing. Faults in the blood-brain barrier can contribute to neurological diseases, but the blood-brain barrier can also restrict drugs from accessing the brain, making it difficult to treat certain conditions. Understanding how the endothelial cells that form the blood-brain barrier develop may offer insight into new treatments for neurological diseases. During the development of the embryo, endothelial cells develop from stem cells. They can also be generated in the laboratory from human pluripotent stem cells or ‘hPSCs’, which are cells that can produce more cells like themselves, or differentiate into any cell type in the body. Scientists can treat hPSCs with specific molecules to make them differentiate into endothelial cells, or to modify their properties. This allows researchers to monitor how different types of endothelial cells form. Endothelial cells at the blood-brain barrier are one of these types. During their development, these cells gain distinct features, including the production of proteins called GLUT-1, claudin-5 and LSR. GLUT-1 transports glucose across endothelial cells’ membranes, while claudin-5 and LSR tightly join adjacent cells together, preventing molecules from leaking into the brain through the space between cells. In mouse endothelial cells, a signaling protein called Wnt is responsible for turning on the genes that code for these proteins. But how does Wnt signaling impact human endothelial cells? Gastfriend et al. probed the effects of Wnt signaling on human endothelial cells grown in the lab as they differentiate from hPSCs. They found that human endothelial cells developed distinct blood-brain barrier features when Wnt signaling was activated, producing GLUT-1, claudin-5 and LSR. Gastfriend et al. also found that human endothelial cells were more responsive to Wnt signaling earlier in their development. Additionally, they identified the genes that became activated in human endothelial cells when Wnt signaling was triggered. These findings provide insight into the development and features of the endothelial cells that form the human blood-brain barrier. The results are a first step towards a better understanding of how this structure works in humans. This information may also allow researchers to develop new ways to deliver drugs into the brain.