KATP channels as biomechanical sensors in the regulation of ductus arteriosus tone

项目总结： 动脉导管是连接肺和全身的重要血管分流管。 胎儿生命中的循环。出生时，DA必须关闭，以便对新充气的肺进行充分的灌流。 然而，在某些情况下，DA无法关闭，这种情况被称为动脉导管未闭(PDA)。掌上电脑是一种 严重的心血管疾病，每500-2000年足月新生儿中就有1例，大多数 危重早产儿。目前的治疗方法有限，且存在令人担忧的非靶向效应。完成工作 过去三十年已经确定了DA通畅的“主要调节器”，即氧气、前列腺素和 一氧化氮信号。然而，pda的临床难题仍然存在，这表明还有其他不明原因的疾病。 DA语气的关键调节者。DA经历了一组独特的生物力学力量，使其有别于 体内的所有其他血管。血流模式和管壁伸展在治疗期间发生了显著变化。 地方检察官关闭的过程。然而，机械感觉以前并没有作为DA的调节器被研究过 语气。 其他人已经确定了一类离子通道，KATP通道，它可以感知和响应细胞内 血管内皮细胞和平滑肌细胞的生物力学作用力。我们证明了检察官对 生物力学力的变化和KATP通道在DA中的丰富和调节音调的作用。 此外，KATP通道基因突变的人类患有坎图综合症，这是一种疾病 以掌上电脑为特征的。因此，这一建议的主要假设是KATP通道调节DA音调 通过充当新的生物力学传感器，在出生时触发DA关闭并驱动循环适应。我们 将使用微流控或微流控培养的原代DA内皮和平滑肌细胞来解决这一假设 伸展装置。这些实验将阐明激活DA-KATP通道的参数 或被特定的血流动力学力量抑制。此外，我们将从单个细胞转移到完整的DAS，通过 用于确定KATP通道的分子机制的流动图实验 地方检察官的机械感应系统。综上所述，这些研究将确定KATP以前未知的角色 通道作为DA中的生物力学传感器。此外，通过确定KATP的分子机制 通道机械传感，这些研究将把KATP通道置于已建立的调节器的层次结构中 并为目前的DA闭合模式增加了一个新的生物力学组件。最后，这些 研究将使我们能够将我们的发现整合到人类PDA的病理生理学中，以获得更多 对早产儿和坎图综合征患者经常发生的动脉导管未闭的完全了解 希望开发出更有效的治疗方案。

Project Summary: The ductus arteriosus (DA) is a critical vascular shunt connecting the pulmonary and systemic circulations during fetal life. At birth, the DA must close to allow adequate perfusion of the newly inflated lungs. However, the DA fails to close in some cases, a condition termed patent ductus arteriosus (PDA). PDA is a significant cardiovascular disorder affecting 1 out of every 500-2000 term infants and 30-40% of the most critically ill premature neonates. Current therapies are limited and have worrisome off-target effects. Work over the past thirty years has identified the “master regulators” of DA patency, namely oxygen, prostaglandins, and nitric oxide signaling. However, the clinical conundrum of PDA persists, suggesting there are other unidentified critical regulators of DA tone. The DA experiences a unique set of biomechanical forces that set it apart from all other vessels in the body. Blood flow patterns and vessel wall stretching changes dramatically during the course of DA closure. And yet, mechanosensing has not been previously investigated as a regulator of DA tone. Others have identified a class of ion channels, KATP channels, that sense and respond to changes in biomechanical forces in endothelial and smooth muscle cells. We demonstrated that the DA is sensitive to changes in biomechanical forces and that KATP channels are enriched in the DA and serve to regulate tone. Moreover, humans with mutations in KATP channel genes suffer from Cantu Syndrome, a disorder characterized by PDA. Therefore, the major hypothesis of this proposal is that KATP channels regulate DA tone by acting as novel biomechanical sensors that trigger DA closure and drive circulatory adaptation at birth. We will address this hypothesis using primary DA endothelial and smooth muscle cells cultured in microfluidic or stretch devices. These experiments will elucidate the parameters under which DA KATP channels are activated or inhibited by specific hemodynamic forces. Additionally we will move from individual cells to intact DAs via flow-myography experiments in order to determine the molecular mechanism underlying KATP channel mechanosensing in the DA. Taken together, these studies will identify a previously unknown role for KATP channels as biomechanical sensors in the DA. Moreover, by determining the molecular mechanisms of KATP channel mechanosensing, these studies will place KATP channels within the hierarchy of established regulators of DA tone and add a novel biomechanical component to the current paradigm of DA closure. Finally, these studies will allow us to integrate our findings into the pathophysiology of PDA in humans to gain a more complete understanding of the PDAs that often occur in pre-term infants and Cantu syndrome patients with the hopes of developing more efficient therapeutic options.