Department of Respiratory and Critical Care Medicine, The First Affiliated Hospital of Xi'an Jiaotong University, No. 277, West Yanta Road, Xi'an, 710061, Shaanxi, China.
Department of Respiratory and Critical Care Medicine, The First Affiliated Hospital of Sun Yat-Sen University, Guangzhou, 510080, Guangdong, China.
Respir Res. 2023 Jun 2;24(1):149. doi: 10.1186/s12931-023-02454-x.
HMGB1 and ER stress have been considered to participate in the progression of pulmonary artery hypertension (PAH). However, the molecular mechanism underlying HMGB1 and ER stress in PAH remains unclear. This study aims to explore whether HMGB1 induces pulmonary artery smooth muscle cells (PASMCs) functions and pulmonary artery remodeling through ER stress activation.
Primary cultured PASMCs and monocrotaline (MCT)-induced PAH rats were applied in this study. Cell proliferation and migration were determined by CCK-8, EdU and transwell assay. Western blotting was conducted to detect the protein levels of protein kinase RNA-like endoplasmic reticulum kinase (PERK), activating transcription factor-4 (ATF4), seven in absentia homolog 2 (SIAH2) and homeodomain interacting protein kinase 2 (HIPK2). Hemodynamic measurements, immunohistochemistry staining, hematoxylin and eosin staining were used to evaluate the development of PAH. The ultrastructure of ER was observed by transmission electron microscopy.
In primary cultured PASMCs, HMGB1 reduced HIPK2 expression through upregulation of ER stress-related proteins (PERK and ATF4) and subsequently increased SIAH2 expression, which ultimately led to PASMC proliferation and migration. In MCT-induced PAH rats, interfering with HMGB1 by glycyrrhizin, suppression of ER stress by 4-phenylbutyric acid or targeting SIAH2 by vitamin K3 attenuated the development of PAH. Additionally, tetramethylpyrazine (TMP), as a component of traditional Chinese herbal medicine, reversed hemodynamic deterioration and vascular remodeling by targeting PERK/ATF4/SIAH2/HIPK2 axis.
The present study provides a novel insight to understand the pathogenesis of PAH and suggests that targeting HMGB1/PERK/ATF4/SIAH2/HIPK2 cascade might have potential therapeutic value for the prevention and treatment of PAH.
高迁移率族蛋白 B1（HMGB1）和内质网应激（ER 应激）被认为参与了肺动脉高压（PAH）的进展。然而，HMGB1 和 ER 应激在 PAH 中的分子机制尚不清楚。本研究旨在探讨 HMGB1 是否通过 ER 应激激活诱导肺动脉平滑肌细胞（PASMC）功能和肺血管重构。
本研究应用原代培养的 PASMC 和野百合碱（MCT）诱导的 PAH 大鼠。通过 CCK-8、EdU 和 Transwell 测定法检测细胞增殖和迁移。通过 Western blot 检测蛋白激酶 RNA 样内质网激酶（PERK）、激活转录因子 4（ATF4）、七结构域缺失蛋白 2（SIAH2）和同源结构域相互作用蛋白激酶 2（HIPK2）的蛋白水平。血流动力学测量、免疫组织化学染色、苏木精和伊红染色用于评估 PAH 的发展。通过透射电子显微镜观察 ER 的超微结构。
在原代培养的 PASMC 中，HMGB1 通过上调 ER 应激相关蛋白（PERK 和 ATF4）降低 HIPK2 表达，进而增加 SIAH2 表达，最终导致 PASMC 增殖和迁移。在 MCT 诱导的 PAH 大鼠中，通过甘草甜素干扰 HMGB1、通过 4-苯丁酸抑制 ER 应激或通过维生素 K3 靶向 SIAH2，可减轻 PAH 的发展。此外，作为中药的一种成分，川芎嗪通过靶向 PERK/ATF4/SIAH2/HIPK2 轴逆转了血液动力学恶化和血管重构。
本研究为理解 PAH 的发病机制提供了新的见解，并表明靶向 HMGB1/PERK/ATF4/SIAH2/HIPK2 级联可能具有预防和治疗 PAH 的潜在治疗价值。
