title: Inactivation of menin, the product of the multiple endocrine neoplasia type 1 gene, inhibits the commitment of multipotential mesenchymal stem cells into the osteoblast lineage.
abstract: The physiological roles of menin, the product of the multiple endocrine neoplasia type 1 gene, are not known. Homozygous menin knockout mice exhibit cranial and facial hypoplasia. We, therefore, investigated the role of menin in the regulation of osteoblastic differentiation. Menin antisense oligonucleotides (AS-oligo) reduced endogenous menin expression in the C3H10T1/2 (10T1/2) mouse mesenchymal stem cells and antagonized alkaline phosphatase (ALP) activity and the expression of type I collagen, Runx2/cbfa1 (Runx2), and osteocalcin (OCN) induced by bone morphogenetic protein 2 (BMP-2). AS-oligo did not affect adipogenic markers (Oil red staining and PPARgamma expression) and chondrogenic markers (Alcian blue staining and type IX collagen) induced by BMP-2 in 10T1/2 cells. Menin co-immunoprecipitated with Smad1 and Smad5, and inactivation of menin antagonized BMP-2-induced transcriptional activity of Smad1/5. In osteoblastic MC3T3-E1 cells, AS-oligo affected neither BMP-2-stimulated ALP activity nor the expression of Runx2 and OCN. Stable inactivation of menin in MC3T3-E1 cells increased ALP activity, mineralization, and the expression of type I collagen and OCN. In 21-day cultures of MC3T3-E1 cells and BMP-2-treated 10T1/2 cells, endogenous menin expression increased up to day 14 and declined thereafter. These data indicate that menin inactivation specifically inhibits the commitment of pluripotent mesenchymal stem cells to the osteoblast lineage, mediated by menin and Smad1/5 interactions. Menin is important for both early differentiation of osteoblasts and inhibition of their later differentiation, and it might be crucial for intramembranous ossification.
authors.affiliation: Division of Endocrinology, Department of Clinical Molecular Medicine, Kobe University Graduate School of Medicine, 7-5-2 Kusunoki-Cho, Chuo-ku, Kobe 650-0017, Japan.
authors.forename: Hideaki
authors.initials: H
authors.lastname: Sowa
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Kaji
authors.forename: Lucie
authors.initials: L
authors.lastname: Canaff
authors.forename: Geoffrey N
authors.initials: GN
authors.lastname: Hendy
authors.forename: Tatsuo
authors.initials: T
authors.lastname: Tsukamoto
authors.forename: Toru
authors.initials: T
authors.lastname: Yamaguchi
authors.forename: Kohei
authors.initials: K
authors.lastname: Miyazono
authors.forename: Toshitsugu
authors.initials: T
authors.lastname: Sugimoto
authors.forename: Kazuo
authors.initials: K
authors.lastname: Chihara
mesh_terms: D016475:3T3 Cells; D017667:Adipocytes / Q000166:cytology / Q000378:metabolism; D000818:Animals; D055396:Bone Morphogenetic Protein 2; D019485:Bone Morphogenetic Proteins / Q000494:pharmacology; D002454:Cell Differentiation / Q000187:drug effects / Q000502:physiology; D019070:Cell Lineage / Q000187:drug effects / Q000502:physiology; D002478:Cells, Cultured; D019902:Chondrocytes / Q000166:cytology / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000378:metabolism; D015870:Gene Expression; D008648:Mesoderm / Q000166:cytology; D051379:Mice; D008809:Mice, Inbred C3H; D018761:Multiple Endocrine Neoplasia Type 1 / Q000378:metabolism; D009363:Neoplasm Proteins / Q000235:genetics* / Q000378:metabolism*; D016376:Oligonucleotides, Antisense / Q000494:pharmacology; D010006:Osteoblasts / Q000166:cytology* / Q000378:metabolism; D010750:Phosphoproteins / Q000378:metabolism; D011518:Proto-Oncogene Proteins; D051785:Smad Proteins; D051898:Smad1 Protein; D051902:Smad5 Protein; D013234:Stem Cells / Q000166:cytology* / Q000378:metabolism; D015534:Trans-Activators / Q000378:metabolism; D016212:Transforming Growth Factor beta
chemical_list: C525719:Bmp2 protein, mouse; D055396:Bone Morphogenetic Protein 2; D019485:Bone Morphogenetic Proteins; D004268:DNA-Binding Proteins; C105373:MEN1 protein, human; D009363:Neoplasm Proteins; D016376:Oligonucleotides, Antisense; D010750:Phosphoproteins; D011518:Proto-Oncogene Proteins; D051785:Smad Proteins; D051898:Smad1 Protein; C497401:Smad1 protein, mouse; D051902:Smad5 Protein; C497798:Smad5 protein, mouse; D015534:Trans-Activators; D016212:Transforming Growth Factor beta