Ventura Telma, Fidanza Antonella, Wilson Marieangela C, Ferguson Daniel C J, Lewis Phillip A, May Alisha, Taylor Helen, Rimmer Michael P, Gregory Christopher D, Frayne Jan, Forrester Lesley M
Centre for Regenerative Medicine, Institute for Regeneration and Repair, University of Edinburgh, Edinburgh, United Kingdom.
Edinburgh Medical School, Biomedical Sciences, University of Edinburgh, Edinburgh, United Kingdom.
Front Mol Biosci. 2024 Apr 16;11:1370933. doi: 10.3389/fmolb.2024.1370933. eCollection 2024.
Erythroblastic island (EBI) macrophages play an essential role in the production and maturation of the vast numbers of red blood cells (RBCs) that are produced throughout life. Their location within the bone marrow makes it difficult to study the cellular and molecular interactions associated with their action so we have used an model of the EBI niche using macrophages derived from human induced pluripotent stem cells (hiPSCs). We previously demonstrated that the activation of the transcription factor KLF1 enhanced the activity of hiPSC-derived EBI macrophages. To elucidate the mechanisms associated with EBI-like activity we carried out a quantitative proteomic analysis and assessed the role of extracellular vesicles using Nanosight Tracking analyses and media filtration. Gene ontology analysis showed that many of the proteins upregulated by KLF1 were protein-binding factors, some of which were associated with the cell membrane or extracellular vesicles We demonstrated that filtration of macrophage-conditioned media resulted in a reduction in the supportive effects on erythroid cell viability and maturation implying a role for extracellular vesicles but this was not KLF1 dependent. Pathway analyses of the proteomic data revealed that proteins upregulated by KLF1 were associated with the citric acid cycle, pyruvate metabolism and ATP synthesis indicating that KLF1-activated macrophages had a metabolic profile comparable to a pro-reparative phenotype. This study has generated a proteomic dataset that could provide new insights into the role of macrophages within the EBI niche and has indicated a potential role for extracellular vesicles in the differentiation and maturation of RBCs . Further research will aid in the production of RBCs for use in disease modelling and cell therapy.
成红细胞岛（EBI）巨噬细胞在一生中产生的大量红细胞（RBC）的生成和成熟过程中发挥着至关重要的作用。它们在骨髓中的位置使得研究与其作用相关的细胞和分子相互作用变得困难，因此我们使用了一种EBI生态位模型，该模型采用源自人诱导多能干细胞（hiPSC）的巨噬细胞。我们之前证明转录因子KLF1的激活增强了hiPSC衍生的EBI巨噬细胞的活性。为了阐明与EBI样活性相关的机制，我们进行了定量蛋白质组学分析，并使用纳米颗粒跟踪分析和培养基过滤评估了细胞外囊泡的作用。基因本体分析表明，许多由KLF1上调的蛋白质是蛋白质结合因子，其中一些与细胞膜或细胞外囊泡相关。我们证明，对巨噬细胞条件培养基进行过滤会导致对红系细胞活力和成熟的支持作用降低，这意味着细胞外囊泡发挥了作用，但这并不依赖于KLF1。蛋白质组学数据的通路分析显示，由KLF1上调的蛋白质与柠檬酸循环、丙酮酸代谢和ATP合成相关，表明KLF1激活的巨噬细胞具有与促修复表型相当的代谢特征。这项研究生成了一个蛋白质组数据集，该数据集可以为巨噬细胞在EBI生态位中的作用提供新的见解，并表明细胞外囊泡在RBC分化和成熟中具有潜在作用。进一步的研究将有助于生产用于疾病建模和细胞治疗的RBC。
