title: Class 3 semaphorins are transcriptionally regulated by 1,25(OH)2D3in osteoblasts.
abstract: The vitamin D endocrine system is essential for calcium metabolism and skeletal integrity. 1,25-dihydroxyvitamin D3[1,25(OH)2D3] regulates bone mineral homeostasis and acts directly on osteoblasts. In the present study we characterized the transcriptional regulation of the class 3 semaphorin (Sema3) gene family by 1,25(OH)2D3in osteoblastic cells. Class 3 semaphorins are secreted proteins that regulate cell growth, morphology and migration, and were recently shown to be involved in bone homeostasis. In ST2, MC3T3-E1 and primary calvarial osteoblast cell cultures we found that all members of the Sema3 gene family were expressed, and that Sema3e and Sema3f were the most strongly induced 1,25(OH)2D3target genes among the studied cell types. In addition, transcription of Sema3b and Sema3c was upregulated, whereas Sema3d and Sema3g was downregulated by 1,25(OH)2D3in different osteoblastic cells. Chromatin immunoprecipitation analysis linked to DNA sequencing (ChIP-seq analysis) revealed the presence of the vitamin D receptor at multiple genomic loci in the proximity of Sema3 genes, demonstrating that the genes are primary 1,25(OH)2D3targets. Furthermore, we showed that recombinant SEMA3E and SEMA3F protein were able to inhibit osteoblast proliferation. However, recombinant SEMA3s did not affect ST2 cell migration. The expression of class 3 semaphorins in osteoblasts together with their regulation by 1,25(OH)2D3suggests that these genes, involved in the regulation of bone homeostasis, are additional mediators for 1,25(OH)2D3signaling in osteoblasts.
authors.affiliation: Clinical and Experimental Endocrinology, KULeuven, Herestraat 49, Bus 902, 3000 Leuven, Belgium. Electronic address: jussi.ryynanen@med.kuleuven.be.
authors.forename: Jussi
authors.initials: J
authors.lastname: Ryynänen
authors.affiliation: Clinical and Experimental Endocrinology, KULeuven, Herestraat 49, Bus 902, 3000 Leuven, Belgium. Electronic address: c.kriebitzsch@gmx.net.
authors.forename: Carsten
authors.initials: C
authors.lastname: Kriebitzsch
authors.affiliation: Department of Biochemistry, University of Wisconsin-Madison, Madison, WI, 53706, USA. Electronic address: mmeyer@biochem.wisc.edu.
authors.forename: Mark B
authors.initials: MB
authors.lastname: Meyer
authors.affiliation: Clinical and Experimental Endocrinology, KULeuven, Herestraat 49, Bus 902, 3000 Leuven, Belgium. Electronic address: iris.janssens@med.kuleuven.be.
authors.forename: Iris
authors.initials: I
authors.lastname: Janssens
authors.affiliation: Department of Biochemistry, University of Wisconsin-Madison, Madison, WI, 53706, USA. Electronic address: pike@biochem.wisc.edu.
authors.forename: J Wesley
authors.initials: JW
authors.lastname: Pike
authors.affiliation: Clinical and Experimental Endocrinology, KULeuven, Herestraat 49, Bus 902, 3000 Leuven, Belgium. Electronic address: lieve.verlinden@med.kuleuven.be.
authors.forename: Lieve
authors.initials: L
authors.lastname: Verlinden
authors.affiliation: Clinical and Experimental Endocrinology, KULeuven, Herestraat 49, Bus 902, 3000 Leuven, Belgium. Electronic address: mieke.verstuyf@med.kuleuven.be.
authors.forename: Annemieke
authors.initials: A
authors.lastname: Verstuyf
mesh_terms: D000818:Animals; D002117:Calcitriol / Q000378:metabolism*; D002460:Cell Line; D049109:Cell Proliferation; D002478:Cells, Cultured; D003598:Cytoskeletal Proteins; D006023:Glycoproteins / Q000235:genetics; D008565:Membrane Proteins / Q000235:genetics; D051379:Mice; D009419:Nerve Tissue Proteins / Q000235:genetics; D010006:Osteoblasts / Q000166:cytology / Q000378:metabolism*; D039961:Semaphorins / Q000235:genetics*; D015533:Transcriptional Activation
chemical_list: D003598:Cytoskeletal Proteins; D006023:Glycoproteins; D008565:Membrane Proteins; D009419:Nerve Tissue Proteins; C526269:Sema3b protein, mouse; C111150:Sema3e protein, mouse; C491229:Sema3f protein, mouse; D039961:Semaphorins; C505763:semaphorin 3G, mouse; D002117:Calcitriol
keywords: Gene expression regulation; Osteoblast; Semaphorin; Transcription; Vitamin D; Vitamin d receptor