Linked Life Data

9138075

Source:http://linkedlifedata.com/resource/pubmed/id/9138075

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1
pubmed:dateCreated
1997-6-30
pubmed:abstractText
To examine possible mechanisms underlying osteoblast differentiation from mesenchymal stem cells, we investigated bHLH functional activity in cell lines representing different stages of osteoblast maturation. Interaction of nuclear proteins with oligonucleotides corresponding to various bHLH binding sequences (known as E-boxes) was determined in mobility shift assays. Both ADD-1 oligonucleotide, a binding site for transcription factor ADD-1, and OCE-1, an E-box from osteocalcin promoter, produced retarded bands after incubation with nuclear extracts from osteogenic cells. Cells at different stages of osteogenic maturation demonstrated similar patterns and intensity of binding, as did cells treated with different osteogenic inducers. Binding to ADD-1 and OCE-1 was not tissue-specific as it was also observed in fibroblastic 10T1/2 cells. MEF-1 oligonucleotide, the E-box sequence from the muscle creatine kinase enhancer, demonstrated no changes in binding with nuclear extracts from moderately differentiated (W-20) or relatively mature (ROS 17/2.8) cells under any conditions tested. However, in poorly differentiated RI-2J cells, which do not express osteogenic markers unless treated with dexamethasone, induction of differentiation was reflected in transient inhibition of binding to MEF-1. Inhibition of binding was not seen under differentiation-restrictive conditions. Promoter-reporter studies also demonstrated inhibition of MEF-1 driven CAT expression by dexamethasone under differentiation-permissive conditions in RI-2J cells. These data suggest that bHLH gene expression is not required for the early steps of osteogenesis; moreover, inhibition of bHLH protein binding to a MEF1-type E box might be an integral part of osteogenic commitment.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Apr
pubmed:issn
0730-2312
pubmed:author
pubmed:issnType
Print
pubmed:volume
65
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
1-10
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed-meshheading:9138075-Alkaline Phosphatase, pubmed-meshheading:9138075-Animals, pubmed-meshheading:9138075-Binding Sites, pubmed-meshheading:9138075-Blotting, Northern, pubmed-meshheading:9138075-Bone Marrow Cells, pubmed-meshheading:9138075-Cyclic AMP, pubmed-meshheading:9138075-DNA, Complementary, pubmed-meshheading:9138075-DNA-Binding Proteins, pubmed-meshheading:9138075-Dexamethasone, pubmed-meshheading:9138075-Gene Expression, pubmed-meshheading:9138075-Glucocorticoids, pubmed-meshheading:9138075-Helix-Loop-Helix Motifs, pubmed-meshheading:9138075-Mice, pubmed-meshheading:9138075-MyoD Protein, pubmed-meshheading:9138075-Nuclear Proteins, pubmed-meshheading:9138075-Osteoblasts, pubmed-meshheading:9138075-Osteosarcoma, pubmed-meshheading:9138075-RNA, Messenger, pubmed-meshheading:9138075-Rats, pubmed-meshheading:9138075-Rats, Wistar, pubmed-meshheading:9138075-Regulatory Sequences, Nucleic Acid, pubmed-meshheading:9138075-Transcription Factors
pubmed:year
1997
pubmed:articleTitle
HLH transcription factor activity in osteogenic cells.
pubmed:affiliation
Department of Biochemistry, School of Dental Medicine, University of Pennsylvania, Philadelphia 19104-6003, USA.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, Non-U.S. Gov't