Analysis of activin A gene expression in human bone marrow stromal cells
Analysis of activin A gene expression in human bone marrow stromal cells
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DOI：
10.1002/(sici)1097-4644(19980701)70:1
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发表时间：
1998-07-01
影响因子：
4
通讯作者：
Yu, J
中科院分区：
文献类型：
--
作者：
Dolter, KE;Palyash, JC;Yu, J
活化素A是TGF-β超家族的成员，在分化和发育中发挥作用，包括造血。我们的前期研究表明，人骨髓细胞和单核细胞激活素A的表达受炎性细胞因子和糖皮质激素的高度调节。本研究旨在探讨激活素A基因在人骨髓基质细胞系L 87/4和HS-5以及原代基质细胞中的表达调控。北方印迹表明，像原代基质细胞，细胞系表达四种激活素A RNA转录物（6.4，4.0，2.8和1.6 kb），尽管四种大小的RNA分布不同。通过北方印迹和RNA酶保护测定研究RNA的5'末端的位置。结果鉴定了翻译起始密码子上游212个核苷酸处的转录起始位点。此外，使用一系列缺失构建体的荧光素酶表达测定来鉴定激活素A基因上游的调控序列。一个58 bp的上游序列表现出启动子活性。然而，几倍更高的表达需要由额外的71 bp的上游区域组成的阳性元件。启动子活性也被确定在起始密码子上游2.5和3.6 kb之间。这些发现表明，激活素A在转录水平的表达遵循复杂的调控模式。(C)1998 Wiley-Liss Inc.
Activin A, a member of the TGF-beta superfamily, plays roles in differentiation and development, including hematopoiesis. Our previous studies indicated that the expression of activin A by human bone marrow cells and monocytes is highly regulated by inflammatory cytokines and glucocorticoids. The present study was undertaken to investigate the regulation of activin A gene expression in the human bone marrow stromal cell lines L87/4 and HS-5, as well as in primary stromal cells. Northern blots demonstrated that, like primary stromal cells, the cell lines expressed four activin A RNA transcripts (6.4, 4.0, 2.8, and 1.6 kb), although distribution of the RNA among the four sizes varied. The locations of the 5' ends of the RNAs were investigated by Northern blots and RNase protection assays. The results identified a transcription start site at 212 nucleotides upstream of the translation start codon. In addition, luciferase expression assays of a series of deletion constructs were used to identify regulatory sequences upstream of the activin A gene. A 58 bp upstream sequence exhibits promoter activity. However, severalfold higher expression requires a positive element consisting of an additional 71 bp of the upstream region. Promoter activity was also identified between 2.5 and 3.6 kb upstream of the start codon. These findings suggest that expression of activin A at the transcriptional level follows complex patterns of regulation. (C) 1998 Wiley-Liss Inc.