Functional analysis of TET2 using a knockdown mouse model
Functional analysis of TET2 using a knockdown mouse model
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使用敲除小鼠模型对 TET2 进行功能分析
DOI：
10.11406/rinketsu.56.657
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发表时间：
2015
期刊：
影响因子：
--
通讯作者：
下田和哉
中科院分区：
文献类型：
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作者：
幣光太郎;亀田拓郎;下田和哉
在骨髓恶性肿瘤中，表观遗传调节基因发生突变，包括10 - 11-易位2（TET 2）。TET 2是一种催化5-甲基胞嘧啶转化为5-羟甲基胞嘧啶（5-hmC）的酶，5-hmC是氧化DNA去甲基化的关键中间体。我们使用通过基因捕获方法产生的Ayu 17 -449（TET 2（trap/trap））小鼠分析TET 2失败的体内表型，其中TET 2 mRNA水平降低至野生型（WT）小鼠中水平的约20%。在TET 2（陷阱/陷阱）小鼠中，与WT小鼠相比，骨髓（BM）细胞基因组DNA中的5-hmC水平降低。TET 2（陷阱/陷阱）小鼠以预期的孟德尔频率出生，但在出生后第3天死亡率很高，表明TET 2对生存至关重要。在造血系统分析中，TET 2（trap/trap）移植，而非WT胎肝细胞移植，导致WT受体小鼠轻度骨髓增生和脾肿大，但在12个月的随访期间未观察到致死性血液恶性肿瘤的发作。TET 2敲低导致体外BM细胞的连续再铺板能力增加，并且在竞争性再增殖和连续移植测定中体内造血干细胞（HSC）自我更新增加。这些数据表明TET 2在存活和HSC稳态中具有关键作用。
In myeloid malignancies, mutations have occurred in epigenetic regulator genes, including Ten-Eleven-Translocation 2 (TET2). TET2 is an enzyme that catalyzes the conversion of 5-methylcytosine into 5-hydroxymethylcytosine (5-hmC) which is a key intermediate for oxidative DNA demethylation. We analyzed the in vivo phenotype of TET2 failure using Ayu17-449 (TET2 (trap/trap)) mice created by the gene-trap method in which TET2 mRNA levels were decreased to about 20% of the level in wild-type (WT) mice. In TET2 (trap/trap) mice the levels of 5-hmC in genomic DNA from bone marrow (BM) cells were decreased in comparison to WT mice. TET2 (trap/trap) mice were born at an expected Mendelian frequency but died at a high rate by postnatal day 3, indicating TET2 to be essential for survival. In analysis of the hematopoietic system, transplantation of TET2 (trap/trap), but not WT fetal liver cells, led to mild myeloid hyperplasia and splenomegaly in WT recipient mice, but no onsets of lethal hematological malignancies were observed during a follow-up period of 12 months. TET2 knockdown led to an increased serial replating capacity of BM cells in vitro and increased hematopoietic stem cell (HSC) self-renewal in vivo in competitive repopulation and serial transplantation assays. These data indicate that TET2 has a critical role in survival and HSC homeostasis.