Hirsch Kellen, Mandrycky Christian J, Kwan Isabella, Pi Hongyang, Altemeier William A, Lahm Tim, Leary Peter J, Gharib Sina A, Zheng Ying, Rayner Samuel G
University of Utah, Division of Cardiology, Department of Internal Medicine, Salt Lake City, UT.
University of Washington, Department of Bioengineering, Seattle, WA.
bioRxiv. 2025 Jul 31:2025.07.28.666693. doi: 10.1101/2025.07.28.666693.
Hemodynamic forces exert a profound influence on endothelial signaling and, when abnormal, contribute centrally to human vascular disease. Pulmonary arterial hypertension (PAH) is characterized by both hemodynamic derangement and pulmonary arterial endothelial cell (PAEC) dysfunction. Despite importance in disease initiation and progression, the combined effects of shear and pressure forces on PAEC biology remain incompletely understood, particularly in the context of PAH.
PAECs obtained at explant from controls and patients with idiopathic PAH or congenital heart disease-associated PAH (CHD-PAH) were cultured in a custom resistor-coupled microfluidic platform and exposed to static, low (3 dyne/cm), or high (20 dyne/cm) shear stress under either low or elevated (60 mmHg) pressure. After 24 hours, we assessed cellular morphology and performed transcriptomic analysis via bulk RNA sequencing, incorporating analyses of PAH subtype and donor sex.
Morphologically, PAECs (n=18 donors) aligned with flow under high, but not low, shear, and alignment was not significantly altered by disease state or pressure. As expected, shear stress fundamentally reorganized the PAEC transcriptome. The "dose-response" to increasing shear differed across biological pathways in six statistically significant patterns. Increasing shear led to divergence in transcription between control and PAH cells, particularly in pathways involved in immune activation, stress signaling, and vascular remodeling, with subtype differences also observed. Pressure had modest effects on transcription, with CHD-PAH PAECs notably displaying pressure-induced stress and inflammatory signaling. We identified sexual dimorphism in the endothelial shear response, including that male cells under shear enriched for proliferative and angiogenic pathways and female cells for fatty acid metabolism and stress responses.
We provide a systems-level overview of how shear and pressure shape PAEC transcription, revealing divergent responses across disease state, PAH subtype, and donor sex. These findings highlight the need for further investigation into mechanosensitive pathways in PAH as potential novel therapeutic targets.
血流动力学力对内皮信号传导有深远影响，异常时在人类血管疾病中起核心作用。肺动脉高压（PAH）的特征是血流动力学紊乱和肺动脉内皮细胞（PAEC）功能障碍。尽管在疾病的发生和发展中很重要，但剪切力和压力对PAEC生物学的综合影响仍未完全了解，尤其是在PAH的背景下。
从对照组以及特发性PAH或先天性心脏病相关PAH（CHD-PAH）患者的外植体中获取PAEC，在定制的电阻耦合微流控平台中培养，并在低或升高（60 mmHg）压力下暴露于静态、低（3达因/平方厘米）或高（20达因/平方厘米）剪切应力。24小时后，我们评估细胞形态，并通过大量RNA测序进行转录组分析，纳入PAH亚型和供体性别的分析。
形态学上，PAEC（n = 18名供体）在高剪切而非低剪切下与血流方向对齐，并且对齐情况不受疾病状态或压力的显著影响。正如预期的那样，剪切应力从根本上重组了PAEC转录组。在六个具有统计学意义的模式中，不同生物学途径对增加剪切力的“剂量反应”不同。剪切力增加导致对照组和PAH细胞之间的转录差异，特别是在免疫激活、应激信号传导和血管重塑相关途径中，也观察到亚型差异。压力对转录有适度影响，CHD-PAH的PAEC尤其表现出压力诱导的应激和炎症信号传导。我们在内皮剪切反应中发现了性别二态性，包括剪切下的雄性细胞富集增殖和血管生成途径，而雌性细胞富集脂肪酸代谢和应激反应途径。
我们提供了一个系统层面的概述，说明剪切力和压力如何塑造PAEC转录，揭示了疾病状态、PAH亚型和供体性别之间的不同反应。这些发现凸显了进一步研究PAH中机械敏感途径作为潜在新治疗靶点的必要性。
