Supplemental Digital Content is available in the text. Pulmonary hypertension (PH) is a rare and fatal disorder involving the vascular remodeling of pulmonary arteries mediated by the enhanced proliferation of pulmonary artery smooth muscle cells (PASMCs). Long noncoding RNAs are a subclass of regulatory molecules with diverse cellular functions, but their role in PH remains largely unexplored. We aimed to identify and determine the functions of long noncoding RNAs involved in hypoxia-induced PH and PASMC proliferation. RNA sequencing in a hypoxic mouse model identified hypoxia-regulated long noncoding RNAs, including Rps4l. Rps4l expression was significantly reduced in PH-model mice and hypoxic PASMCs. The subcellular localization of Rps4l was detected by RNA fluorescence in situ hybridization and quantification of nuclear/cytoplasmic RNA. Rps4l overexpression rescued pulmonary arterial hypertension features, as demonstrated by right ventricle hypertrophy, right ventricular systolic pressure, hemodynamics, cardiac function, and vascular remodeling. At the cellular level, Rps4l overexpression weakened cell viability and proliferation and suppressed cell cycle progression. Potential Rps4l-binding proteins were identified via RNA pull-down followed by mass spectrometry, RNA immunoprecipitation, and microscale thermophoresis. These results indicated that Rps4l is associated with and affects the stabilization of ILF3 (interleukin enhancer-binding factor 3). Rps41 further regulates the levels of HIF-1α and consequently leads to hypoxia-induced PASMC proliferation and migration. Our results showed that in hypoxic PASMCs, Rps4l expression decreases due to regulation by hypoxia. This decrease affects the proliferation, migration, and cell cycle progression of PASMCs through ILF3/HIF-1α. These results provide a theoretical basis for further investigations into the pathological mechanism of hypoxic PH and may provide insight for the development of novel treatments.

中文翻译：

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长链非编码 RNA Rps4l 介导缺氧肺动脉平滑肌细胞的增殖

补充数字内容在文本中可用。肺动脉高压 (PH) 是一种罕见且致命的疾病，涉及由肺动脉平滑肌细胞 (PASMC) 增殖增强介导的肺动脉血管重塑。长链非编码 RNA 是具有多种细胞功能的调节分子的一个亚类，但它们在 PH 中的作用在很大程度上仍未得到探索。我们旨在鉴定和确定参与缺氧诱导的 PH 和 PASMC 增殖的长链非编码 RNA 的功能。缺氧小鼠模型中的 RNA 测序鉴定了缺氧调节的长非编码 RNA，包括 Rps4l。Rps4l 表达在 PH 模型小鼠和缺氧 PASMC 中显着降低。Rps41 的亚细胞定位通过 RNA 荧光原位杂交和核/细胞质 RNA 的定量检测。Rps4l 过表达挽救了肺动脉高压特征，如右心室肥大、右心室收缩压、血流动力学、心脏功能和血管重塑所证明的。在细胞水平上，Rps4l 过表达减弱了细胞活力和增殖并抑制了细胞周期进程。潜在的 Rps4l 结合蛋白通过 RNA 下拉、质谱、RNA 免疫沉淀和微量热泳来鉴定。这些结果表明 Rps4l 与 ILF3（白介素增强子结合因子 3）相关并影响其稳定性。Rps41 进一步调节 HIF-1α 的水平，从而导致缺氧诱导的 PASMC 增殖和迁移。我们的结果表明，在缺氧的 PASMC 中，由于缺氧的调节，Rps4l 表达降低。这种减少通过 ILF3/HIF-1α 影响 PASMC 的增殖、迁移和细胞周期进程。这些结果为进一步研究缺氧PH的病理机制提供了理论基础，并可能为开发新的治疗方法提供见解。