Herberth B, Minkó K, Csillag A, Jaffredo T, Madarász E
Institute of Experimental Medicine of Hungarian Academy of Sciences, Neural Cell Biology Group, Szigony u. 43, 1083 Budapest, Hungary.
Int J Dev Neurosci. 2005 Aug;23(5):449-63. doi: 10.1016/j.ijdevneu.2005.05.008.
SCL, Lmo2 and GATA factors form common transcription complexes during hematopoietic differentiation. The overlapping expression of SCL with GATA-2 and GATA-3 in the developing brain indicated that these factors might collaborate also in the course of neural tissue differentiation. The expression pattern of Lmo2 in the developing CNS, however, is not well understood. Here, we show that neural cells in the early embryonic chick mid- and hindbrain express SCL and GATA-2, while Lmo2 is expressed only in vascular elements. The lack of Lmo2 transcripts in neural cells demonstrated that SCL and GATA-2 cannot form common complexes with Lmo2 in the developing brain. In the course of neural tissue genesis, GATA-2 mRNA appeared prior to the SCL transcript. While GATA-2 expression decreased with maturation, SCL expression persisted at a high level also in post-neurogenic periods. The temporal pattern of SCL and GATA-2/3 expression was investigated also in vitro, in the course of induced neurogenesis by NE-4C neural stem cells. While GATA-2 expression increased from the very beginning of differentiation, SCL expression appeared only in more differentiated cells expressing proneural genes. GATA-3 expression, on the other hand, was detected only in advanced stages of the neuronal maturation, which were characterised by the activation of the Math2 neuronal gene. Similarly to the hematopoietic differentiation, GATA-2 expression precedes the activation of both SCL and GATA-3, and may play roles in the activation of the SCL gene in neuronal development. In contrast to hematopoietic differentiation, however, our results failed to demonstrate co-assembling of GATA factors or SCL with Lmo2. While overlapping expression of GATA-2/3 and SCL was detected, Lmo2 activation could not be demonstrated in neural cells in the investigated period of neuronal development.
在造血分化过程中，SCL、Lmo2和GATA因子形成共同的转录复合体。SCL与GATA - 2和GATA - 3在发育中的大脑中重叠表达，这表明这些因子在神经组织分化过程中也可能协同作用。然而，Lmo2在发育中的中枢神经系统中的表达模式尚不清楚。在这里，我们表明，早期胚胎鸡中脑和后脑的神经细胞表达SCL和GATA - 2，而Lmo2仅在血管成分中表达。神经细胞中缺乏Lmo2转录本表明，在发育中的大脑中，SCL和GATA - 2不能与Lmo2形成共同的复合体。在神经组织发生过程中，GATA - 2 mRNA在SCL转录本之前出现。虽然GATA - 2的表达随着成熟而降低，但SCL的表达在神经发生后的时期也持续维持在高水平。我们还在体外由NE - 4C神经干细胞诱导神经发生的过程中研究了SCL和GATA - 2/3表达的时间模式。虽然GATA - 2的表达从分化一开始就增加，但SCL的表达仅出现在表达神经前体基因的更分化的细胞中。另一方面，GATA - 3的表达仅在神经元成熟的晚期被检测到，其特征是Math2神经元基因的激活。与造血分化类似，GATA - 2的表达先于SCL和GATA - 3的激活，并且可能在神经元发育中SCL基因的激活中发挥作用。然而，与造血分化不同的是，我们的结果未能证明GATA因子或SCL与Lmo2的共同组装。虽然检测到GATA - 2/3和SCL的重叠表达，但在所研究的神经元发育时期，神经细胞中未能证明Lmo2的激活。
