Thompson Gunnar B, Barnhouse Victoria R, Bierman Sydney K, Harley Brendan A C
Department of Chemical and Biomolecular Engineering, University of Illinois at Urbana-Champaign, Urbana, IL, 61801, USA.
Department of Bioengineering, University of Illinois at Urbana-Champaign, Urbana, IL, 61801, USA.
Adv Healthc Mater. 2025 May;14(14):e2500858. doi: 10.1002/adhm.202500858. Epub 2025 Apr 26.
Hematopoietic stem cell (HSC) fate is shaped by distinct microenvironments termed niches within the bone marrow. Quiescence, expansion, and differentiation are directly and indirectly regulated by complex combinations of cell secretomes, cell-cell interactions, mechanical signals, and metabolic factors including oxygen tension. The perivascular environment in the bone marrow has been implicated in guiding HSC fate. However, bone marrow presents an environment which is hypoxic (≈1-4% O) relative to traditional cell culture conditions, and the study of hypoxia in vitro is complicated by the speed with which normoxic conditions during HSC isolation induce differentiation. There is a unique opportunity to use engineered models of the bone marrow to investigate the impact of defined hypoxia on HSC fate. Here, the coordinated impact of oxygen tension and the perivascular secretome upon murine hematopoietic stem and progenitor cells (HSPCs) is examined in vitro. The findings highlight the importance of mitigating oxygen shock during cell isolation in engineered marrow models. We report a shift toward the Lineage phenotype with hypoxic culture, expansion of HSPCs in response to perivascular niche conditioned medium, and enhanced HSPC maintenance in a hydrogel model of bone marrow in hypoxic culture when oxygen shock is mitigated during isolation using cyclosporin A.
造血干细胞（HSC）的命运由骨髓内被称为龛的独特微环境塑造。静止、增殖和分化直接或间接受细胞分泌组、细胞间相互作用、机械信号以及包括氧张力在内的代谢因子的复杂组合调控。骨髓中的血管周围环境被认为在引导造血干细胞命运方面发挥作用。然而，相对于传统细胞培养条件，骨髓呈现出低氧环境（约1 - 4%氧气），并且体外低氧研究因造血干细胞分离过程中常氧条件诱导分化的速度而变得复杂。利用工程化的骨髓模型来研究特定低氧对造血干细胞命运的影响存在独特的机会。在此，体外研究了氧张力和血管周围分泌组对小鼠造血干细胞和祖细胞（HSPCs）的协同影响。研究结果突出了在工程化骨髓模型中细胞分离过程中减轻氧应激的重要性。我们报告了低氧培养时向谱系表型的转变、对血管周围龛条件培养基的反应中造血干细胞和祖细胞的增殖，以及当使用环孢素A在分离过程中减轻氧应激时，在低氧培养的骨髓水凝胶模型中造血干细胞和祖细胞维持能力的增强。
