Linked Life Data

21302293

Source:http://linkedlifedata.com/resource/pubmed/id/21302293

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
11
pubmed:dateCreated
2011-9-21
pubmed:abstractText
We have previously demonstrated that glutamate (Glu) suppresses cellular proliferation toward self-renewal through a mechanism associated with intracellular GSH depletion mediated by the bidirectional cystine/Glu antiporter in osteoblastic MC3T3-E1 cells cultured in the absence of differentiation inducers. To further evaluate the possible role of the antiporter in osteoblastogenesis, in this study, we have established stable transfectants of the xCT subunit of the antiporter in MC3T3-E1 cells. Stable overexpression led to a significant facilitation of cellular proliferation determined by different indices with increased GSH levels and decreased ROS generation in addition to promoted [(14)C]cystine incorporation, while Glu failed to significantly inhibit cellular proliferation in stable xCT transfectants. In stable transfectants cultured under differentiation conditions, drastic decreases were invariably seen in Ca(2+) accumulation, alkaline phosphatase activity and several osteoblastic marker gene expressions, in addition to downregulation of mRNA and corresponding protein for runt-related transcription factor-2 (Runx2). Runx2 promoter activity was significantly promoted by the introduction of Runx2 expression vector in a manner sensitive to the prevention by the co-introduction of xCT expression vector in MC3T3-E1 cells. In both MC3T3-E1 cells and murine calvarial osteoblasts cultured with differentiation inducers, transient transfection with xCT siRNA significantly increased Runx2 protein expression along with decreases in xCT mRNA expression and 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazolium bromide reduction. These results suggest that the cystine/Glu antiporter plays a pivotal role in cellular differentiation through a mechanism related to the regulation of transactivation of Runx2 essential for osteoblastogenesis toward maturation in osteoblastic cells.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Nov
pubmed:issn
1097-4652
pubmed:author
pubmed:copyrightInfo
Copyright © 2011 Wiley-Liss, Inc.
pubmed:issnType
Electronic
pubmed:volume
226
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
2953-64
pubmed:meshHeading
pubmed:year
2011
pubmed:articleTitle
Negative regulation of osteoblastogenesis through downregulation of runt-related transcription factor-2 in osteoblastic MC3T3-E1 cells with stable overexpression of the cystine/glutamate antiporter xCT subunit.
pubmed:affiliation
Laboratory of Molecular Pharmacology, Division of Pharmaceutical Sciences, Kanazawa University Graduate School of Natural Science and Technology, Kanazawa, Ishikawa, Japan.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't