title: Systematic assessment of the human osteoblast transcriptome in resting and induced primary cells.
abstract: Osteoblasts are key players in bone remodeling. The accessibility of human primary osteoblast-like cells (HObs) from bone explants makes them a lucrative model for studying molecular physiology of bone turnover, for discovering novel anabolic therapeutics, and for mesenchymal cell biology in general. Relatively little is known about resting and dynamic expression profiles of HObs, and to date no studies have been conducted to systematically assess the osteoblast transcriptome. The aim of this study was to characterize HObs and investigate signaling cascades and gene networks with genomewide expression profiling in resting and bone morphogenic protein (BMP)-2- and dexamethasone-induced cells. In addition, we compared HOb gene expression with publicly available samples from the Gene Expression Omnibus. Our data show a vast number of genes and networks expressed predominantly in HObs compared with closely related cells such as fibroblasts or chondrocytes. For instance, genes in the insulin-like growth factor (IGF) signaling pathway were enriched in HObs (P = 0.003) and included the binding proteins (IGFBP-1, -2, -5) and IGF-II and its receptor. Another HOb-specific expression pattern included leptin and its receptor (P < 10(-8)). Furthermore, after stimulation of HObs with BMP-2 or dexamethasone, the expression of several interesting genes and pathways was observed. For instance, our data support the role of peripheral leptin signaling in bone cell function. In conclusion, we provide the landscape of tissue-specific and dynamic gene expression in HObs. This resource will allow utilization of osteoblasts as a model to study specific gene networks and gene families related to human bone physiology and diseases.
authors.affiliation: McGill University and Genome Quebec Innovation Centre, Montreal, Canada.
authors.forename: Elin
authors.initials: E
authors.lastname: Grundberg
authors.forename: Helena
authors.initials: H
authors.lastname: Brändström
authors.forename: Kevin C L
authors.initials: KC
authors.lastname: Lam
authors.forename: Scott
authors.initials: S
authors.lastname: Gurd
authors.forename: Bing
authors.initials: B
authors.lastname: Ge
authors.forename: Eef
authors.initials: E
authors.lastname: Harmsen
authors.forename: Andreas
authors.initials: A
authors.lastname: Kindmark
authors.forename: Osten
authors.initials: O
authors.lastname: Ljunggren
authors.forename: Hans
authors.initials: H
authors.lastname: Mallmin
authors.forename: Olle
authors.initials: O
authors.lastname: Nilsson
authors.forename: Tomi
authors.initials: T
authors.lastname: Pastinen
mesh_terms: D000328:Adult; D055396:Bone Morphogenetic Protein 2; D019485:Bone Morphogenetic Proteins / Q000494:pharmacology; D002478:Cells, Cultured; D002940:Circadian Rhythm / Q000187:drug effects / Q000235:genetics; D016000:Cluster Analysis; D003907:Dexamethasone / Q000494:pharmacology; D005260:Female; D020869:Gene Expression Profiling; D005786:Gene Expression Regulation / Q000187:drug effects; D005938:Glucocorticoids / Q000494:pharmacology; D006801:Humans; D007334:Insulin-Like Growth Factor I / Q000235:genetics; D020738:Leptin / Q000235:genetics; D008297:Male; D008875:Middle Aged; D010006:Osteoblasts / Q000737:chemistry / Q000187:drug effects / Q000378:metabolism*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D015398:Signal Transduction / Q000187:drug effects; D016212:Transforming Growth Factor beta / Q000494:pharmacology
chemical_list: C525718:BMP2 protein, human; D055396:Bone Morphogenetic Protein 2; D019485:Bone Morphogenetic Proteins; D005938:Glucocorticoids; D020738:Leptin; D016212:Transforming Growth Factor beta; D007334:Insulin-Like Growth Factor I; D003907:Dexamethasone