Effect of geometrical constraints on human pluripotent stem cell nuclei in pluripotency and differentiation
Effect of geometrical constraints on human pluripotent stem cell nuclei in pluripotency and differentiation
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DOI：
10.1039/c7ib00194k
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发表时间：
2018-05-01
影响因子：
2.5
通讯作者：
Elvassore, Nicola
中科院分区：
文献类型：
--
作者：
Grespan, Eleonora;Giobbe, Giovanni G.;Elvassore, Nicola
通过细胞骨架传递到细胞核的机械刺激和几何约束影响细胞核的形态和细胞功能。人多能干细胞（hPSC）代表了用于评估核变形性从多能阶段到分化阶段的转变以及用于破译潜在机制的有效工具。我们报告的第一项研究，调查核变形性诱导的几何约束的hPSC在多能性阶段和早期胚层规格。我们专门开发了微结构表面，结合高含量的成像分析算法，以定量表征核变形能力。我们的结果表明，hPSC具有高的核变形能力，这不会改变多能性。我们观察到核变形过渡沿着早期胚层规范：在早期外胚层分化核变形能力强烈降低，在早期内胚层分化核保持变形的形状和早期中胚层规范，他们表现出中间的行为。已经观察到在平坦表面和微结构表面上分化的hPSC之间的不同mRNA表达沿着沿着早期中胚层和早期内胚层特化。为了更好地了解早期外胚层分化过程中观察到的核变形性转变的机制，我们还采用了细胞骨架和核蛋白抑制剂来评估它们在确定核形状中的作用。肌动蛋白和nesprin是维持变形的细胞核所必需的，而核纤层蛋白A/C和中间丝赋予细胞核刚性。这项研究表明，核变形能力在分化过程中受到高度调节。
Mechanical stimuli and geometrical constraints transmitted across the cytoskeleton to the nucleus affect the nuclear morphology and cell function. Human pluripotent stem cells (hPSCs) represent an effective tool for evaluating transitions in nuclear deformability from the pluripotent to differentiated stage, and for deciphering the underlying mechanisms. We report the first study that investigates the nuclear deformability induced by geometrical constraints of hPSCs both in the pluripotent stage and during early germ layer specification. We specifically developed micro-structured surfaces coupled with high-content imaging analysis algorithms to quantitatively characterize nuclear deformability. Our results show that hPSCs possess high nuclear deformability, which does not alter pluripotency. We observed nuclear deformability transition along early germ layer specification: during early ectoderm differentiation nuclear deformability is strongly reduced, during early endoderm differentiation nuclei keep a deformed shape and during early mesoderm specification they show an intermediate behaviour. Different mRNA expressions between hPSCs differentiated on flat and micro-structured surfaces have been observed along early mesoderm and early endoderm specification. In order to better understand the mechanisms of the nuclear deformability transition observed during early ectoderm differentiation, we also employed cytoskeletal and nuclear protein inhibitors to evaluate their role in determining the nuclear shape. Actin and nesprin are essential for maintaining deformed nuclei, while lamin A/C and intermediate filaments confer rigidity to the nucleus. This study suggests that nuclear deformability is highly regulated during differentiation.