Menin is required for bone morphogenetic protein 2- and transforming growth factor β-regulated osteoblastic differentiation through interaction with Smads and Runx2
Menin is required for bone morphogenetic protein 2- and transforming growth factor β-regulated osteoblastic differentiation through interaction with Smads and Runx2
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DOI：
10.1074/jbc.m401312200
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发表时间：
2004-09-24
影响因子：
4.8
通讯作者：
Chihara, K
中科院分区：
文献类型：
--
作者：
Sowa, H;Kaji, H;Chihara, K
多发性内分泌瘤形成1型（MEN 1）基因的产物Menin是多潜能间充质干细胞向成骨细胞谱系定型所需的，然而，它抑制它们的后期分化（Sowa，H.，Kaji，H.，卡纳夫湖，亨迪，G. N.，Tsukamoto，T.，山口，T.，Miyazono，K.，Sugimoto，T.，和Chihara，K.（2003）J.Biol.Chem.278，21058 - 21069）。在这里，我们研究了menin在调节成骨细胞分化的作用机制，使用小鼠骨髓基质ST 2和成骨细胞MC 3 T3-E1细胞系。在ST 2细胞中，通过转染menin反义DNA（AS）实现的menin表达减少拮抗骨形态发生蛋白（BMP）-2诱导的碱性磷酸酶活性和骨钙素和Runx 2 mRNA表达。Menin与ST 2和MC 3 T3-E1细胞中的Smad 1/5共免疫沉淀，menin的失活拮抗ST 2细胞中BMP-2诱导的Smad 1/5转录活性，但不拮抗MC 3 T3-E1细胞中的Smad 1/5转录活性。Menin与关键的成骨细胞调节因子Runx 2共免疫沉淀，AS拮抗Runx 2的转录活性和Runx 2刺激碱性磷酸酶活性的能力，仅在ST 2细胞中，而不是在MC 3 T3-E1细胞中。在成骨细胞MC 3 T3-E1细胞中，转化生长因子β及其信号分子Smad 3负调控Runx 2转录活性。Menin和Smad 3共免疫沉淀，并结合menin和Smad 3过表达拮抗，而menin和显性负性Smad 3 DeltaC一起增强BMP-2诱导的Smad 1/5和Runx 2的转录活性。Smad 3单独使用没有效果。因此，menin在未定型间充质干细胞中与Runx 2在物理和功能上相互作用，但在分化良好的成骨细胞中不相互作用。在成骨细胞中，menin和转化生长因子β/Smad 3通路的相互作用负调节BMP-2/Smad 1/5和Runx 2诱导的转录活性，导致晚期分化的抑制。
Menin, the product of the multiple endocrine neoplasia type 1 (MEN1) gene, is required for commitment of multipotential mesenchymal stem cells to the osteoblast lineage, however, it inhibits their later differentiation (Sowa, H., Kaji, H., Canaff, L., Hendy, G. N., Tsukamoto, T., Yamaguchi, T., Miyazono, K., Sugimoto, T., and Chihara, K. ( 2003) J. Biol. Chem. 278, 21058 - 21069). Here, we have examined the mechanism of action of menin in regulating osteoblast differentiation using the mouse bone marrow stromal ST2 and osteoblast MC3T3-E1 cell lines. In ST2 cells, reduced menin expression achieved by transfection of menin antisense DNA ( AS) antagonized bone morphogenetic protein (BMP)-2-induced alkaline phosphatase activity and osteocalcin and Runx2 mRNA expression. Menin was co-immunoprecipitated with Smad1/5 in ST2 and MC3T3-E1 cells, and inactivation of menin antagonized BMP-2-induced transcriptional activity of Smad1/5 in ST2 cells, but not MC3T3-E1 cells. Menin was co-immunoprecipitated with the key osteoblast regulator, Runx2, and AS antagonized Runx2 transcriptional activity and the ability of Runx2 to stimulate alkaline phosphatase activity only in ST2 cells but not in MC3T3-E1 cells. In the osteoblast MC3T3-E1 cells, transforming growth factor-beta and its signaling molecule, Smad3, negatively regulated Runx2 transcriptional activity. Menin and Smad3 were co-immunoprecipitated, and combined menin and Smad3 overexpression antagonized, whereas menin and the dominant-negative Smad3DeltaC together enhanced BMP-2-induced transcriptional activity of Smad1/5 and Runx2. Smad3 alone had no effect. Therefore, menin interacts physically and functionally with Runx2 in uncommitted mesenchymal stem cells, but not in well differentiated osteoblasts. In osteoblasts the interaction of menin and the transforming growth factor-beta/Smad3 pathway negatively regulates the BMP-2/Smad1/5- and Runx2-induced transcriptional activities leading to inhibition of late-tage differentiation.