O-GlcNAc Transferase Regulates Angiogenesis in Idiopathic Pulmonary Arterial Hypertension
O-GlcNAc Transferase Regulates Angiogenesis in Idiopathic Pulmonary Arterial Hypertension
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DOI：
10.3390/ijms20246299
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发表时间：
2019-12-01
影响因子：
5.6
通讯作者：
Dweik, Raed A.
中科院分区：
文献类型：
--
作者：
Barnes, Jarrod W.;Tian, Liping;Dweik, Raed A.
特发性肺动脉高压（IPAH）被认为是一种血管病，其特征是由于血管收缩和/或肺重塑（如丛状病变，PAH的标志）以及细胞增殖和血管和血管生成功能障碍引起的肺血管阻力升高。丝氨酸/苏氨酸羟基连接的N-乙酰葡糖胺（O-GlcNAc）转移酶（OGT）已被证明可驱动IPAH中的肺动脉平滑肌细胞（PASMC）增殖。OGT是一种细胞营养传感器，通过调节细胞信号传导、增殖和代谢，对维持正常细胞功能至关重要。本研究的目的是确定OGT和O-GlcNAc在IPAH的血管和血管生成功能障碍中的作用。原代分离的人对照和IPAH患者PASMC和肺动脉内皮细胞（PAEC）在存在或不存在OGT抑制剂的情况下生长，并在单层培养物和管形成试验、体外血管发芽3D球体共培养模型和NODSCID小鼠中的新生血管化模型中进行生化评估。我们发现，敲低OGT导致IPAH原代分离的血管细胞中血管内皮生长因子（VEGF）表达减少。此外，特异性蛋白1（SP1），一种已知的VEGF表达刺激物，在生理（5 mM）和高（25 mM）葡萄糖浓度下，与对照组相比，在IPAH中显示出更高的O-GlcNAc水平，敲低导致VEGF蛋白水平降低。此外，与对照PAEC相比，人IPAH PAEC表现出显著更高程度的毛细管样结构和增加的长度。添加OGT抑制剂OSMI-1显着减少了管状结构的数量和管长，与对照水平相似。使用IPAH和对照PAEC/PASMC的体外3D球体共培养模型和使用对照和PAEC包埋的胶原植入物的体内血管化模型的血管发芽评估表明，与对照相比，IPAH中的血管化更高。然而，在这些实验中阻断OGT活性改变了IPAH中的血管发芽和新生血管形成，与对照组相比，与对照组水平相似。我们在本报告中的研究结果是第一个描述的作用，OGT/O-GlcNAc轴在调节血管内皮生长因子的表达和血管化的IPAH。这些发现提供了更深入的了解，改变葡萄糖摄取和代谢可能对血管生成过程和丛状病变的发展的潜在作用。因此，我们认为OGT/O-GlcNAc轴可能是治疗IPAH中存在的血管生成失调的潜在治疗靶点。
Idiopathic pulmonary arterial hypertension (IPAH) is considered a vasculopathy characterized by elevated pulmonary vascular resistance due to vasoconstriction and/or lung remodeling such as plexiform lesions, the hallmark of the PAH, as well as cell proliferation and vascular and angiogenic dysfunction. The serine/threonine hydroxyl-linked N-Acetylglucosamine (O-GlcNAc) transferase (OGT) has been shown to drive pulmonary arterial smooth muscle cell (PASMC) proliferation in IPAH. OGT is a cellular nutrient sensor that is essential in maintaining proper cell function through the regulation of cell signaling, proliferation, and metabolism. The aim of this study was to determine the role of OGT and O-GlcNAc in vascular and angiogenic dysfunction in IPAH. Primary isolated human control and IPAH patient PASMCs and pulmonary arterial endothelial cells (PAECs) were grown in the presence or absence of OGT inhibitors and subjected to biochemical assessments in monolayer cultures and tube formation assays, in vitro vascular sprouting 3D spheroid co-culture models, and de novo vascularization models in NODSCID mice. We showed that knockdown of OGT resulted in reduced vascular endothelial growth factor (VEGF) expression in IPAH primary isolated vascular cells. In addition, specificity protein 1 (SP1), a known stimulator of VEGF expression, was shown to have higher O-GlcNAc levels in IPAH compared to control at physiological (5 mM) and high (25 mM) glucose concentrations, and knockdown resulted in decreased VEGF protein levels. Furthermore, human IPAH PAECs demonstrated a significantly higher degree of capillary tube-like structures and increased length compared to control PAECs. Addition of an OGT inhibitor, OSMI-1, significantly reduced the number of tube-like structures and tube length similar to control levels. Assessment of vascular sprouting from an in vitro 3D spheroid co-culture model using IPAH and control PAEC/PASMCs and an in vivo vascularization model using control and PAEC-embedded collagen implants demonstrated higher vascularization in IPAH compared to control. Blocking OGT activity in these experiments, however, altered the vascular sprouting and de novo vascularization in IPAH similar to control levels when compared to controls. Our findings in this report are the first to describe a role for the OGT/O-GlcNAc axis in modulating VEGF expression and vascularization in IPAH. These findings provide greater insight into the potential role that altered glucose uptake and metabolism may have on the angiogenic process and the development of plexiform lesions. Therefore, we believe that the OGT/O-GlcNAc axis may be a potential therapeutic target for treating the angiogenic dysregulation that is present in IPAH.