Abstract

Mixed populations of cardiosphere-derived stem and progenitor cells containing proliferative and cardiomyogenically committed cells were obtained from adult rat hearts. The cells were cultured in either static 2D monolayers or dynamic 3D scaffold systems with fluid flow. Cardiomyocyte lineage commitment in terms of GATA4 and Nkx2.5 expression was significantly enhanced in the dynamic 3D cultures compared with static 2D conditions. Treatment of the cells with 5-azacytidine (5-aza) produced different responses in the two culture systems, as activity of this chemical epigenetic conditioning agent depended on the cell attachment and hydrodynamic conditions provided during culture. Cell growth was unaffected by 5-aza in the static 2D cultures but was significantly reduced under dynamic 3D conditions relative to untreated controls. Myogenic differentiation measured as Mef2c expression was markedly upregulated by 5-aza in the dynamic 3D cultures but downregulated in the static 2D cultures. The ability of the physical environment to modulate the cellular cardiomyogenic response to 5-aza underscores the interactivity of biochemical and physical stimuli applied for cell differentiation. Accordingly, observations about the efficacy of 5-aza as a cardiomyocyte induction agent may not be applicable across different culture systems. Overall, use of dynamic 3D rather than static 2D culture was more beneficial for cardio-specific myogenesis than 5-aza treatment, which generated a more ambiguous differentiation response.

中文翻译：

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成年心脏干细胞和祖细胞的表观遗传调节和心肌细胞分化过程中生化和物理刺激的相互作用

摘要

从成年大鼠心脏获得含有增殖性和心肌原性细胞的心肌球衍生干细胞和祖细胞的混合群。细胞在具有流体流动的静态 2D 单层或动态 3D 支架系统中培养。与静态 2D 条件相比，动态 3D 培养物中 GATA4 和 Nkx2.5 表达的心肌细胞谱系承诺显着增强。用 5-氮杂胞苷 (5-aza) 处理细胞在两种培养系统中产生了不同的反应，因为这种化学表观遗传调节剂的活性取决于培养过程中提供的细胞附着和流体动力学条件。细胞生长在静态 2D 培养中不受 5-aza 的影响，但在动态 3D 条件下相对于未经处理的对照显着降低。测量为 Mef2c 表达的肌原性分化在动态 3D 培养中被 5-aza 显着上调，但在静态 2D 培养中下调。物理环境调节细胞对 5-氮杂的心肌细胞反应的能力强调了应用于细胞分化的生化和物理刺激的相互作用。因此，关于 5-aza 作为心肌细胞诱导剂的功效的观察结果可能不适用于不同的培养系统。总体而言，使用动态 3D 而不是静态 2D 培养比 5-aza 治疗更有益于心脏特异性肌生成，后者产生更模糊的分化反应。物理环境调节细胞对 5-氮杂的心肌细胞反应的能力强调了应用于细胞分化的生化和物理刺激的相互作用。因此，关于 5-aza 作为心肌细胞诱导剂的功效的观察结果可能不适用于不同的培养系统。总体而言，使用动态 3D 而不是静态 2D 培养比 5-aza 治疗更有益于心脏特异性肌生成，后者产生更模糊的分化反应。物理环境调节细胞对 5-氮杂的心肌细胞反应的能力强调了应用于细胞分化的生化和物理刺激的相互作用。因此，关于 5-aza 作为心肌细胞诱导剂的功效的观察结果可能不适用于不同的培养系统。总体而言，使用动态 3D 而不是静态 2D 培养比 5-aza 治疗更有益于心脏特异性肌生成，后者产生更模糊的分化反应。