Project description:Bone mineral density (BMD) is a highly heritable predictor of osteoporotic fracture. Genome wide association studies (GWAS) have identified hundreds of loci influencing BMD, but few have been functionally analyzed. In this study, we show that SNPs within a BMD locus on Chromosome 14q32.32 alter splicing and expression of PAR-1a/MARK3, a conserved serine/threonine kinase known to regulate bioenergetics, cell division and polarity. Mice lacking Mark3 either globally or selectively in osteoblasts have increased bone mass at maturity. RNA profiling from Mark3 deficient osteoblasts suggested changes in the expression of components of the Notch signaling pathway. Mark3 deficient osteoblasts exhibited greater matrix mineralization compared with controls that was accompanied by reduced Jag1/Hes1 expression and diminished downstream JNK signaling. Overexpression of Jag1 in Mark3 deficient osteoblasts both in vitro and in vivo normalized mineralization capacity and bone mass, respectively. Together, these findings reveal a mechanism whereby genetically regulated alterations in Mark3 expression perturb cell signaling in osteoblasts to influence bone mass.
Project description:In order to explore molecules whose expression is controlled by Slc39a13, we investigated gene expression profiling of primary osteoblast isolated from wild-type and Slc39a13 knockout mice. Keywords: knockout vs wild-type
Project description:Mucolipidosis type II (MLII) is a severe inherited multisystemic disorder caused by mutations in the GNPTAB gene. Skeletal abnormalities are a predominant feature of MLII. Here we investigate the gene expression in a knock-in mouse model for mucolipidosis type II, generated by the insertion of a cytosine in the murine Gnptab gene (c.3082insC) that is homologous to a homozygous mutation in an MLII patient. Since osteoblasts are critically involved in regulating bone development and remodeling, a genome-wide expression analysis was performed with RNA isolated from primary cultures of osteoblasts originating from MLII knock-in mice (KI) compared to RNA from wild-type (WT) osteoblasts to identify dysregulated genes involved in pathogenic mechanisms. Primary osteoblasts were isolated from calvaria of 5-day-old wild-type (WT) and MLII knock-in littermates (KI). RNA was extracted at day 10 of differentiation induced by ascorbic acid and beta-glycerophosphate and hybridization on Affymetrix microarrays. We used preparations of RNA from two individual primary cultures of osteoblasts for every genotype (WT_OB_I, WT_OB_II, KI_OB_I, KI_OB_II) and compared WT vs KI samples.
Project description:Mucolipidosis type II (MLII) is a severe inherited multisystemic disorder caused by mutations in the GNPTAB gene. Skeletal abnormalities are a predominant feature of MLII. Here we investigate the gene expression in a knock-in mouse model for mucolipidosis type II, generated by the insertion of a cytosine in the murine Gnptab gene (c.3082insC) that is homologous to a homozygous mutation in an MLII patient. Since osteoblasts are critically involved in regulating bone development and remodeling, a genome-wide expression analysis was performed with RNA isolated from primary cultures of osteoblasts originating from MLII knock-in mice (KI) compared to RNA from wild-type (WT) osteoblasts to identify dysregulated genes involved in pathogenic mechanisms.
Project description:In order to explore molecules whose expression is controlled by Slc39a13, we investigated gene expression profiling of primary osteoblast isolated from wild-type and Slc39a13 knockout mice. Keywords: knockout vs wild-type wild-type vs Slc39a13 knockout
Project description:A microRNA array was performed using human primary osteoblasts (hOB) obtained from trabecular bone of postmenopausal women after knee replacement due to osteoarthritis in order to determine the miRNAs expressed in these osteoblastic cells.