Liu Geng, Nie Han, Zhang Xu, Huang Zi-Sheng, Yoshiura Koh-Ichiro, Liu Ke-Xiang, Liu Yi, Li Tao-Sheng
Department of Stem Cell Biology, Atomic Bomb Disease Institute, Nagasaki University, Nagasaki, Japan; Department of Stem Cell Biology, Graduate School of Biomedical Sciences, Nagasaki University, Nagasaki, Japan.
Department of Cardiovascular Surgery, The Second Hospital of Jilin University, Changchun, Jilin, China.
Cell Stress Chaperones. 2025 Jul;30(4):100089. doi: 10.1016/j.cstres.2025.100089. Epub 2025 Jul 2.
Switching from a contractile to a synthetic phenotype of pulmonary arterial smooth muscle cells (PASMCs) is known to play a crucial role in pulmonary arterial hypertension (PAH). We investigated how hypoxia and mechanical stress mediate the phenotypic switching of PASMCs.
Human PASMCs were used for experiments. Hypoxia treatment was done by culturing cells under 1% O₂. Mechanical stress was induced by loading cells to 50 mmHg hydrostatic pressure. We analyzed cell morphology, cell proliferation, phenotypic marker protein expression, cytokine release, and the activation of stress-related pathways at 24 h after treatment. Bulk and single-cell RNA-sequencing datasets were used to analyze heat shock protein family D member 1 (HSPD1) expression in PAH lungs and PASMCs. Heat shock protein 60 (HSP60) was knocked down in PASMCs by transfection of HSPD1-siRNA.
Either hypoxia or mechanical stress alone induced the morphology change, increased cell proliferation, and promoted the phenotypic switching and inflammatory cytokines release of PASMCs. Interestingly, all those were dramatically enhanced under the combination of hypoxia and mechanical stress. Mechanistically, we found that the combination of hypoxia and mechanical stress not only significantly enhanced the mitochondrial HSP60 expression but also induced its partial redistribution to the cytosol. Bioinformatic analyses also confirmed the elevated HSPD1 expression in PAH lungs and PASMCs. HSP60 knockdown effectively attenuated the phenotypic switching of PASMCs induced by hypoxia and mechanical stress.
Hypoxia- and mechanical stress-induced upregulation of mitochondrial HSP60 is associated with phenotypic switching of PASMCs.
肺动脉平滑肌细胞（PASMCs）从收缩表型转变为合成表型在肺动脉高压（PAH）中起着关键作用。我们研究了缺氧和机械应力如何介导PASMCs的表型转换。
使用人PASMCs进行实验。通过在1% O₂条件下培养细胞进行缺氧处理。通过将细胞加载到50 mmHg静水压来诱导机械应力。我们在处理后24小时分析细胞形态、细胞增殖、表型标记蛋白表达、细胞因子释放以及应激相关途径的激活。使用批量和单细胞RNA测序数据集分析PAH肺组织和PASMCs中热休克蛋白家族D成员1（HSPD1）的表达。通过转染HSPD1-siRNA敲低PASMCs中的热休克蛋白60（HSP60）。
单独的缺氧或机械应力均可诱导PASMCs的形态改变、细胞增殖增加，并促进其表型转换和炎性细胞因子释放。有趣的是，在缺氧和机械应力联合作用下，所有这些变化均显著增强。机制上，我们发现缺氧和机械应力联合作用不仅显著增强了线粒体HSP60的表达，还诱导其部分重新分布到细胞质中。生物信息学分析也证实了PAH肺组织和PASMCs中HSPD1表达升高。HSP60敲低有效减弱了缺氧和机械应力诱导的PASMCs表型转换。
缺氧和机械应力诱导的线粒体HSP60上调与PASMCs的表型转换有关。
