Issitt Theo, Toe Quezia K, Pedersen Sofia L, Shackshaft Thomas, Ghazaly Maziah Mohd, West Laura, Arnold Nadine D, Mahomed Abdul, Kagugube George W, Ramakrishnan Latha, Lawrie Allan, Quinlan Gregory J, Wort S John
NHLI, Faculty of Medicine Imperial College London London UK.
Institute of Tropical Biodiversity and Sustainable Development Univerity of Malaysia Terengganu Malaysia.
Pulm Circ. 2024 Dec 18;14(4):e70006. doi: 10.1002/pul2.70006. eCollection 2024 Oct.
Elevated circulating hepcidin levels have been reported in patients with pulmonary artery hypertension (PAH). Hepcidin has been shown to promote proliferation of human pulmonary artery smooth muscle cells (PASMCs) in vitro, suggesting a potential role in PAH pathogenesis. However, the role of human pulmonary artery endothelial cells (PAECs) as either a source of hepcidin, or the effect of hepcidin on PAEC function is not as well described. The objective of this study was to define the role of the hepcidin-ferroportin axis on the phenotype of PAEC and to study potential PAEC-PASMC interactions relevant to the pathogenesis of pulmonary vascular remodeling and PAH. PAECs treated with hepcidin, or interleukin-6 were investigated for both ferroportin and hepcidin release and regulation using immunofluorescence, mRNA levels and cellular release assays. Effects of hepcidin on PASMC and PAEC mitochondrial function was investigated using immunofluorescence and seahorse assay. Migration and proliferation of PASMCs treated with conditioned media from hPAEC treated with hepcidin was investigated using the xCELLigence system and other tools. We demonstrate in this study that PAECs express ferroportin; hepcidin treatment of PAECs resulted in mitochondrial iron accumulation and intracellular hepcidin biosynthesis and release. Conditioned media from hepcidin treated PAECs caused PASMCs to down-regulate ferroportin expression whilst promoting migration and proliferation. Inhibition of hepcidin in PAEC conditioned media limited these responses. PASMC cellular and mitochondrial iron retention are associated with migratory and proliferative responses. This study confirms that the hepcidin ferroportin axis is present and operational in PAECs. Modulation of this axis shows distinct differences in responses seen between PAECS and PASMCs. Stimulation of this axis in PAECs with hepcidin may well institute proliferative and migratory responses in PASMCs of relevance to pathogenesis of PAH offering potential novel therapeutic targets.
据报道，肺动脉高压（PAH）患者循环中铁调素水平升高。铁调素已被证明在体外可促进人肺动脉平滑肌细胞（PASMCs）增殖，提示其在PAH发病机制中可能发挥作用。然而，人肺动脉内皮细胞（PAECs）作为铁调素来源的作用，或铁调素对PAEC功能的影响尚未得到充分描述。本研究的目的是确定铁调素-铁转运蛋白轴对PAEC表型的作用，并研究与肺血管重塑和PAH发病机制相关的潜在PAEC-PASMC相互作用。使用免疫荧光、mRNA水平和细胞释放试验，研究了用铁调素或白细胞介素-6处理的PAECs中铁转运蛋白和铁调素的释放及调节情况。使用免疫荧光和海马试验研究了铁调素对PASMC和PAEC线粒体功能的影响。使用xCELLigence系统和其他工具，研究了用铁调素处理的hPAEC条件培养基处理的PASMCs的迁移和增殖情况。我们在本研究中证明，PAECs表达铁转运蛋白；铁调素处理PAECs导致线粒体铁积累以及细胞内铁调素生物合成和释放。铁调素处理的PAECs的条件培养基使PASMCs下调铁转运蛋白表达，同时促进迁移和增殖。抑制PAEC条件培养基中的铁调素可限制这些反应。PASMC细胞和线粒体铁潴留与迁移和增殖反应相关。本研究证实，铁调素-铁转运蛋白轴在PAECs中存在并起作用。该轴的调节显示出PAECs和PASMCs之间在反应上的明显差异。用铁调素刺激PAECs中的该轴可能会引发PASMCs中与PAH发病机制相关的增殖和迁移反应，从而提供潜在的新治疗靶点。
