Sp6 downregulation of follistatin gene expression in ameloblasts
Sp6 downregulation of follistatin gene expression in ameloblasts
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DOI：
10.2152/jmi.55.87
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发表时间：
2008-02-01
影响因子：
0.7
通讯作者：
Noma, Takafumi
中科院分区：
文献类型：
--
作者：
Ruspita, Intan;Miyoshi, Keiko;Noma, Takafumi
Sp6是转录因子Sp家族的成员，其调节广泛的细胞功能，例如细胞生长和分化。为了研究Sp6在牙齿发育过程中的作用，我们首先建立了一株Sp6高表达的细胞株CHA 9，并对其细胞增殖和基因表达进行了分析。CHA 9的亲本细胞是我们先前从大鼠下切牙的牙上皮细胞中建立的成釉细胞系G5细胞。Sp6的过量产生加速细胞增殖并诱导成釉细胞分化的标志物成釉蛋白mRNA的表达。其次，我们通过微阵列分析对Sp6靶基因进行了全基因组筛选。在总共20，450个基因中，448个基因被Sp6上调，500个基因被Sp6下调。我们发现，卵泡抑素，BMP拮抗剂的表达，是22.4倍，在CHA 9比对照细胞低。将Sp6反义构建体转染入CHA9细胞后，卵泡抑素的表达恢复到对照细胞中的水平，表明Sp6调节成釉细胞中卵泡抑素基因的表达，我们的研究结果表明，卵泡抑素基因是成釉细胞中Sp6的靶基因之一，并表明Sp6通过抑制卵泡抑素基因的表达来促进成釉细胞的形成。
Sp6 is a member of the Sp family of transcription factors that regulate a wide range of cellular functions, such as cell growth and differentiation. Sp6, also called epiprofin, is specifically expressed in tooth germ, limb bud, and hair follicle, but there is little information on its function.To investigate the possible role of Sp6 in tooth development, first we established an Sp6 overproducing clone, CHA9, and analyzed the features of the cell, including cell proliferation and gene expression. The parental cells of CHA9 are the ameloblast-lineage G5 cells that we previously established from rat dental epithelia of lower incisor. Sp6 overproduction accelerated cell proliferation and induced the expression of ameloblastin mRNA, a marker of ameloblast differentiation. Second, we performed genome- wide screening of Sp6 target genes by microarray analysis. Out of a total 20,450 genes, 448 genes were up-regulated and 500 genes were down-regulated by Sp6. We found the expression of follistatin, a BMP antagonist, to be 22.4-fold lower in CHA9 than in control cells. Transfection of the Sp6-antisense construct into CHA9 cells restored follistatin expression back to equivalent levels seen in control cells, indicating that Sp6 regulates follistatin gene expression in ameloblasts.Our findings demonstrate that the follistatin gene is one of the Sp6 target genes in ameloblasts and suggest that Sp6 promotes amelogenesis through inhibition of follistatin gene expression.