RNA-binding protein Musashi family: Roles for CNS stem cells and a subpopulation of ependymal cells revealed by targeted disruption and antisense ablation
RNA-binding protein Musashi family: Roles for CNS stem cells and a subpopulation of ependymal cells revealed by targeted disruption and antisense ablation
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DOI：
10.1073/pnas.232087499
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发表时间：
2002-11-12
影响因子：
11.1
通讯作者：
Okano, H
中科院分区：
文献类型：
--
作者：
Sakakibara, S;Nakamura, Y;Okano, H
Musashi家族的RNA结合蛋白的同源物在物种间进化上是保守的。在哺乳动物中，该家族的两个成员Musashi 1（Msi 1）和Musashi 2（Msi 2）在神经前体细胞（包括CNS干细胞）中强烈共表达。为了解决在神经发育中的MSI的体内作用，我们产生了有针对性的破坏基因编码的意志的小鼠。纯合子新生小鼠经常发展为阻塞性脑积水，室管膜细胞在中脑导水管周围的限制区域异常增殖。这些观察结果表明msi 1在室管膜细胞亚群的正常发育中起着至关重要的作用，室管膜细胞亚群被推测为出生后CNS干细胞的来源。另一方面，组织学检查和体外神经球试验表明，无论是胚胎中枢神经系统的发展，也没有自我更新的活动，中枢神经系统干细胞在胚胎前脑出现的msi 1的破坏的影响，但由干细胞产生的细胞类型的多样性适度减少的msil缺陷。因此，我们在胚胎神经前体细胞中进行了靶向msil和msi 2的反义消融实验。反义肽-核苷酸，其被设计为特异性下调msi 2的表达，给药msi 1（-/-）CNS干细胞培养物，以剂量依赖性的方式大大抑制了神经球的形成。反义处理的msi 1（-/-）CNS干细胞表现出降低的增殖活性。这些数据表明，msil和msi 2合作参与CNS干细胞群的增殖和维持。
Homologues of the Musashi family of RNA-binding proteins are evolutionarily conserved across species. in mammals, two members of this family, Musashi1 (Msi1) and Musashi2 (Msi2), are strongly coexpressed in neural precursor cells, including CNS stem cells. To address the in vivo roles of msi in neural development, we generated mice with a targeted disruption of the gene encoding Will. Homozygous newborn mice frequently developed obstructive hydrocephalus with aberrant proliferation of ependymal cells in a restricted area surrounding the Sylvius aqueduct. These observations indicate a vital role for msi1 in the normal development of this subpopulation of ependymal cells, which has been speculated to be a source of postnatal CNS stem cells. On the other hand, histological examination and an in vitro neurosphere assay showed that neither the embryonic CNS development nor the self-renewal activity of CNS stem cells in embryonic forebrains appeared to be affected by the disruption of msi1, but the diversity of the cell types produced by the stem cells was moderately reduced by the msil deficiency. Therefore, we performed antisense ablation experiments to target both msil and msi2 in embryonic neural precursor cells. Administration of the antisense peptide-nucleotides, which were designed to specifically down-regulate msi2 expression, to msi1(-/-) CNS stem cell cultures drastically suppressed the formation of neurospheres in a dose-dependent manner. Anti sense-treated msi1(-/-) CNS stem cells showed a reduced proliferative activity. These data suggest that msil and msi2 are cooperatively involved in the proliferation and maintenance of CNS stem cell populations.