Essential role of STAT3 for embryonic stem cell pluripotency
Essential role of STAT3 for embryonic stem cell pluripotency
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DOI：
10.1073/pnas.96.6.2846
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发表时间：
1999-03-16
影响因子：
11.1
通讯作者：
Levy, DE
中科院分区：
文献类型：
--
作者：
Raz, R;Lee, CK;Levy, DE
小鼠胚胎干（ES）细胞的体外增殖需要外源性白血病抑制因子（LIF）或相关细胞因子。 ES 细胞中 LIF 信号的潜在下游效应器包括 Src、Jak 和丝裂原激活蛋白家族的激酶以及信号转导器和转录激活器 STAT3。核STAT3的激活和ES细胞作为未分化克隆生长的能力在LIF撤除期间进行监测，发现STAT3活性水平与克隆密度下未分化表型的维持之间存在相关性。相反，STAT3活性的变化并不影响细胞增殖。通过在表现出不同程度的 LIF 依赖性的 ES 细胞系中进行定向诱变来分析对 STAT3 的需求。插入突变已设计出废除 Stat3 基因表达，但可以通过 Cre 重组介导的切除来逆转，Stat3 突变杂合的 ES 细胞只能从 E14 细胞中分离，该细胞系最不依赖 LIF 进行自我更新。从其他 ES 细胞系中分离出的靶向克隆始终是 11 号染色体三体性的，该染色体携带 Stat3 基因座，并保留了激活 STAT3 的正常水平。 Cre 调节的靶向整倍体 E14 克隆中 Stat3 基因拷贝数的减少导致 STAT3 活性和自我更新效率的剂量依赖性损失，而细胞周期进展没有相应的变化。这些结果证明了关键量的 STAT3 在维持未分化 ES 细胞表型中的重要作用。
Propagation of mouse embryonic stem (ES) cells in vitro requires exogenous leukemia inhibitory factor (LIF) or related cytokines. potential downstream effectors of the LIF signal in ES cells include kinases of the Src, Jak, and mitogen-activated protein families and the signal transducer and transcriptional activator STAT3. Activation of nuclear STAT3 and the ability of ES cells to grow as undifferentiated clones Here monitored during LIF withdrawal, A correlation was found between levels of STAT3 activity and maintenance of an undifferentiated phenotype at clonal density. In contrast, variation in STAT3 activity did not affect cell proliferation. The requirement for STAT3 was analyzed by targeted mutagenesis in ES cell lines exhibiting different degrees of LIF dependency. An insertional mutation Has devised that abrogated Stat3 gene expression but could be reversed by Cre recombination-mediated excision, ES cells heterozygous for the Stat3 mutation could be isolated only from E14 cells, the line least dependent on LIF for self-renewal. Targeted clones isolated from other ES cell lines were invariably trisomic for chromosome 11, which carries the Stat3 locus, and retained normal levels of activated STAT3. Cre-regulated reduction of Stat3 gene copy number in targeted, euploid E14 clones resulted in dose-dependent losses of STAT3 activity and the efficiency of self-renewal without commensurate changes in cell cycle progression. These results demonstrate an essential role for a critical amount of STAT3 in the maintenance of an undifferentiated ES cell phenotype.