College of Pharmacy Harbin Medical University Daqing P. R. China.
Central Laboratory of Harbin Medical University Daqing P. R. China.
J Am Heart Assoc. 2024 Nov 5;13(21):e036757. doi: 10.1161/JAHA.124.036757. Epub 2024 Nov 4.
Unveiling pro-proliferation genes involved in crosstalk between pulmonary artery endothelial cells and pulmonary artery smooth muscle cells (PASMCs) are important to improving the therapeutic outcome of pulmonary hypertension (PH). Although growing studies have shown that super-enhancers (SEs) play a pivotal role in pathological and physiological processes, the SE-associated genes in PH and their impact on PASMC proliferation remain largely unexplored.
We used serotype 5 adenovirus-associated virus to interfere with syndecan-4 and constructed an SU5416 combined with hypoxia-PH model. Chromatin immunoprecipitation sequencing analysis, chromatin immunoprecipitation quantitative polymerase chain reaction, and bioinformatics were used to confirm early growth response 1 was involved in regulating syndecan-4-associated SE in PASMCs. The effects of syndecan-4 and its underlying mechanisms were subsequently elucidated using Western blot, coimmunoprecipitation, and cell coculture assays. Herein, we identified a novel SE-associated gene, syndecan-4, in hypoxia-exposed PASMCs. Syndecan-4 was transcriptionally driven by early growth response 1 via an SE and was significantly overexpressed in hypoxic PASMCs and plasma from patients with PH. Mechanism studies revealed that syndecan-4 induces PASMC proliferation by interacting and regulating protein kinase C α ubiquitination. In addition, syndecan-4 was enriched in exosomes secreted from hypoxic PASMCs, which subsequently transported and led to pulmonary artery endothelial cell dysfunction. Syndecan-4 inhibition in hypoxia by serotype 5 adenovirus-associated virus treatment attenuated the pulmonary artery remodeling and development of PH in vivo.
Taken together, our results demonstrate that an SE-driven syndecan-4 modulates crosstalk of PASMCs and pulmonary artery endothelial cells and promotes vascular remodeling via the protein kinase C α and exosome pathway, thus providing potential targets for the early diagnosis and treatment of hypoxic PH.
揭示肺血管内皮细胞与肺血管平滑肌细胞（PASMC）之间相互作用的促增殖基因对于改善肺动脉高压（PH）的治疗效果非常重要。尽管越来越多的研究表明超级增强子（SEs）在病理和生理过程中发挥着关键作用，但 PH 中的 SE 相关基因及其对 PASMC 增殖的影响在很大程度上仍未得到探索。
我们使用血清型 5 腺相关病毒干扰连接蛋白聚糖-4 并构建了 SU5416 联合低氧-PH 模型。染色质免疫沉淀测序分析、染色质免疫沉淀定量聚合酶链反应和生物信息学用于确认早期生长反应 1 参与调节 PASMC 中连接蛋白聚糖-4 相关 SE。随后使用 Western blot、共免疫沉淀和细胞共培养实验阐明了连接蛋白聚糖-4 的作用及其潜在机制。在此，我们在低氧暴露的 PASMC 中鉴定出一个新的 SE 相关基因连接蛋白聚糖-4。连接蛋白聚糖-4 通过 SE 由早期生长反应 1 转录驱动，在低氧 PASMC 和 PH 患者的血浆中表达显著上调。机制研究表明，连接蛋白聚糖-4 通过相互作用和调节蛋白激酶 Cα泛素化诱导 PASMC 增殖。此外，连接蛋白聚糖-4 在低氧 PASMC 分泌的外泌体中富集，随后这些外泌体运输并导致肺血管内皮细胞功能障碍。通过血清型 5 腺相关病毒治疗在低氧时抑制连接蛋白聚糖-4，可减轻体内肺动脉重塑和 PH 的发展。
综上所述，我们的研究结果表明，SE 驱动的连接蛋白聚糖-4 通过蛋白激酶 Cα和外泌体途径调节 PASMC 和肺血管内皮细胞的相互作用，促进血管重塑，从而为低氧 PH 的早期诊断和治疗提供了潜在的靶点。
