Lee Young Jin, Baskakov Ilia V
a Center for Biomedical Engineering and; Technology Department of Anatomy and Neurobiology ; University of Maryland School of Medicine ; Baltimore , MD USA.
Prion. 2014;8(3):266-75. doi: 10.4161/pri.32079. Epub 2014 Nov 1.
Prion protein, PrP(C), is a glycoprotein that is expressed on the cell surface beginning with the early stages of embryonic stem cell differentiation. Previously, we showed that ectopic expression of PrP(C) in human embryonic stem cells (hESCs) triggered differentiation toward endodermal, mesodermal, and ectodermal lineages, whereas silencing of PrP(C) suppressed differentiation toward ectodermal but not endodermal or mesodermal lineages. Considering that PrP(C) might be involved in controlling the balance between cells of different lineages, the current study was designed to test whether PrP(C) controls differentiation of hESCs into cells of neuron-, oligodendrocyte-, and astrocyte-committed lineages. PrP(C) was silenced in hESCs cultured under three sets of conditions that were previously shown to induce hESCs differentiation into predominantly neuron-, oligodendrocyte-, and astrocyte-committed lineages. We found that silencing of PrP(C) suppressed differentiation toward all three lineages. Similar results were observed in all three protocols, arguing that the effect of PrP(C) was independent of differentiation conditions employed. Moreover, switching PrP(C) expression during a differentiation time course revealed that silencing PrP(C) expression during the very initial stage that corresponds to embryonic bodies has a more significant impact than silencing at later stages of differentiation. The current work illustrates that PrP(C) controls differentiation of hESCs toward neuron-, oligodendrocyte-, and astrocyte-committed lineages and is likely involved at the stage of uncommitted neural progenitor cells rather than lineage-committed neural progenitors.
朊病毒蛋白PrP(C)是一种糖蛋白,从胚胎干细胞分化的早期阶段开始就在细胞表面表达。此前,我们发现,在人类胚胎干细胞(hESC)中异位表达PrP(C)会触发其向内胚层、中胚层和外胚层谱系的分化,而沉默PrP(C)会抑制向外胚层谱系的分化,但不会抑制向内胚层或中胚层谱系的分化。鉴于PrP(C)可能参与控制不同谱系细胞之间的平衡,本研究旨在测试PrP(C)是否控制hESC向神经元、少突胶质细胞和星形胶质细胞定向谱系细胞的分化。在先前已证明可诱导hESC主要分化为神经元、少突胶质细胞和星形胶质细胞定向谱系的三组条件下培养的hESC中,沉默PrP(C)。我们发现,沉默PrP(C)会抑制向所有这三个谱系的分化。在所有这三个实验方案中均观察到了类似结果,这表明PrP(C)的作用与所采用的分化条件无关。此外,在分化时间进程中切换PrP(C)的表达表明,在与胚状体相对应的最早期阶段沉默PrP(C)的表达,比在分化后期沉默具有更显著的影响。当前的研究表明,PrP(C)控制hESC向神经元、少突胶质细胞和星形胶质细胞定向谱系的分化,并且可能在未定向的神经祖细胞阶段而非定向的神经祖细胞阶段发挥作用。