Neuronal differentiation of bone marrow-derived stromal stem cells involves suppression of discordant phenotypes through gene silencing
Neuronal differentiation of bone marrow-derived stromal stem cells involves suppression of discordant phenotypes through gene silencing
复制标题
DOI：
10.1074/jbc.m413796200
复制
发表时间：
2005-06-24
影响因子：
4.8
通讯作者：
Nishimura, I
中科院分区：
文献类型：
--
作者：
Egusa, H;Schweizer, FE;Nishimura, I
组织工程包括构建可移植组织，其中骨髓抽吸物可作为自体多能间充质干细胞的可获得来源。越来越多的报道表明，成体间充质干细胞的谱系限制可能比以前认为的要少，并且基于干细胞的治疗方法等待能够实现规定的表型分化的有效方案的建立。我们研究了成年小鼠骨髓基质细胞（BMSCs）是如何被引导成神经和成骨表型的。幼稚BMSC被发现在广泛的mRNA和蛋白质的表达中具有令人惊讶的活性，包括通常在终末分化的神经元细胞和成骨细胞中报道的那些。幼稚BMSCs表现出类似于神经元引导的BMSCs的电压依赖性膜电流，尽管幅度较小。一旦骨髓间充质干细胞暴露于成骨培养条件下，神经元特征迅速消失。我们的数据表明，BMSC分化过程中不一致表型的丢失不能解释为从整个BMSC群体中选择和消除不合适的细胞。在神经源性或成骨分化培养基中，在最初的8-10天内，所检查的活的与死的BMSC的百分比没有变化，并且细胞脱离估计为<1%。然而，在此期间，骨相关的细胞外基质基因选择性下调神经引导的骨髓基质细胞。这些数据表明，抑制分化中的成体干细胞的不一致表型至少部分是通过沉默多余的基因簇来实现的。
Tissue engineering involves the construction of transplantable tissues in which bone marrow aspirates may serve as an accessible source of autogenous multipotential mesenchymal stem cells. Increasing reports indicate that the lineage restriction of adult mesenchymal stem cells may be less established than previously believed, and stem cell-based therapeutics await the establishment of an efficient protocol capable of achieving a prescribed phenotype differentiation. We have investigated how adult mouse bone marrow-derived stromal cells (BMSCs) are guided to neurogenic and osteogenic phenotypes. Naive BMSCs were found surprisingly active in expression of a wide range of mRNAs and proteins, including those normally reported in terminally differentiated neuronal cells and osteoblasts. The naive BMSCs were found to exhibit voltage-dependent membrane currents similar to the neuronally guided BMSCs, although with smaller amplitudes. Once BMSCs were exposed to the osteogenic culture condition, the neuronal characteristics quickly disappeared. Our data suggest that the loss of discordant phenotypes during BMSC differentiation cannot be explained by the selection and elimination of unfit cells from the whole BMSC population. The percent ratio of live to dead BMSCs examined did not change during the first 8-10 days in either neurogenic or osteogenic differentiation media, and cell detachment was estimated at < 1%. However, during this period, bone-associated extracellular matrix genes were selectively down-regulated in neuronally guided BMSCs. These data indicate that the suppression of discordant phenotypes of differentiating adult stem cells is achieved, at least in part, by silencing of superfluous gene clusters.