The microphthalmia transcription factor regulates expression of the tartrate-resistant acid phosphatase gene during terminal differentiation of osteoclasts
The microphthalmia transcription factor regulates expression of the tartrate-resistant acid phosphatase gene during terminal differentiation of osteoclasts
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DOI：
10.1359/jbmr.2000.15.3.451
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发表时间：
2000-03-01
影响因子：
6.2
通讯作者：
Ostrowski, MC
中科院分区：
文献类型：
--
作者：
Luchin, A;Purdom, G;Ostrowski, MC
小眼畸形转录因子（MITF）基因的mi等位基因纯合子小鼠中破骨细胞的有缺陷的终末分化暗示MITF在破骨细胞个体发育期间调节基因表达中起关键作用。为了开始解决该转录因子在破骨细胞中的作用，需要鉴定靶基因。一些证据表明，编码抗酒石酸酸性磷酸酶（TRAP）的基因对胚胎前肢体内破骨细胞的分析表明，在软骨内分泌过程中，MITE和TRAP RNA以动态模式共表达长骨骨化。从mi/mi突变小鼠产生的原代破骨细胞样细胞（OCL）表达TRAP信使RNA（mRNA）的水平比来自正常小鼠的OCL低8倍，表明MITF功能和TRAP表达之间的直接联系。小鼠TRAP启动子-报告基因的活性通过DNA介导的转染在原代OCL中测定，并且该活性显示依赖于位于近端启动子中的保守序列（GGTCATGTGAG）。重组MITE蛋白特异性识别该保守序列元件。TRAP启动子-绿色荧光蛋白（GFP）转基因的表达模拟了破骨细胞样细胞分化过程中内源性TRAP基因的表达，当置于突变型mi/mi背景中时，转基因的表达降低了8倍。这些结果与MITE在破骨细胞终末分化过程中基因表达中的作用一致，并将使破骨细胞特异性基因调控机制得到更详细的研究。
The defective terminal differentiation of osteoclasts in mice homozygous for the mi allele of the microphthalmia transcription factor (MITF) gene implies that MITF plays a critical role in regulating gene expression during osteoclast ontogeny, To begin addressing the role of this transcription factor in the osteoclast, target genes need to be identified, In the present work, several lines of evidence show that the gene encoding the enzyme tartrate-resistant acid phosphatase (TRAP) is a target of MITE Analysis of osteoclasts in vivo in the embryonic forelimb showed that MITE and TRAP RNA were coexpressed in a dynamic pattern during the process of endochondral ossification of long bone. Primary osteoclast-like cells (OCLs) produced from mi/mi mutant mice expressed TRAP messenger RNA (mRNA) at 8-fold lower levels than in OCLs derived from normal mice, indicating a direct link between MITF function and TRAP expression. The activity of mouse TRAP promoter-reporter genes was assayed in the primary OCLs by DNA-mediated transfection, and this activity was shown to depend on a conserved sequence (GGTCATGTGAG) located in the proximal promoter. Recombinant MITE protein recognized specifically this conserved sequence element. Expression of a TRAP promoter-green fluorescent protein (GFP) transgene mimicked the expression of the endogenous TRAP gene during differentiation of osteoclast-like cells, and the expression of the transgene was decreased 8-fold when placed into the mutant mi/mi background. These results are consistent with a role for MITE in gene expression during terminal differentiation of the osteoclast and will allow osteoclast-specific mechanisms of gene regulation to be studied in greater detail.