Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
3
pubmed:dateCreated
2009-3-5
pubmed:abstractText
Osteoblasts differentiate from mesodermal progenitors and play a pivotal role in bone formation and mineralization. Several transcription factors including runt-related transcription factor 2 (RUNX2), Osterix (OSX), and activating transcription factor4 (ATF4) are known to be crucial for the process, whereas the upstream signal transduction controlling the osteoblast differentiation sequence is largely unknown. Here, we explored the role of c-jun N-terminal kinase (JNK) in osteoblast differentiation using in vitro differentiation models of primary osteoblasts and MC3T3-E1 cells with ascorbic acid/beta-glycerophosphate treatment. Terminal osteoblast differentiation, represented by matrix mineralization, was significantly inhibited by the inactivation of JNK with its specific inhibitor and exogenous overexpression of MKP-M (MAP kinase phosphatase isolated from macrophages), which preferentially inactivates JNK. Conversely, enhanced mineral deposition was observed by inducible overexpression of p54(JNK2), whereas it was not observed by the overexpression of p46(JNK1) or p46(JNK2), indicating a distinct enhancing role of p54(JNK2) in osteoblast differentiation. Inactivation of JNK significantly inhibited late-stage molecular events of osteoblast differentiation, including gene expression of osteocalcin (Ocn) and bone sialoprotein (Bsp). In contrast, earlier differentiation events including alkaline phosphatase (ALP) activation and osteopontin (Opn) expression were not inhibited by JNK inactivation. Although the expression levels of two transcription factor genes, Runx2 and Osx, were not significantly affected by JNK inactivation, induction of Atf4 mRNA during osteoblast differentiation was significantly inhibited. Taken together, these data indicate that JNK activity is specifically required for the late-stage differentiation events of osteoblasts.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
http://linkedlifedata.com/resource/pubmed/chemical/Activating Transcription Factor 4, http://linkedlifedata.com/resource/pubmed/chemical/Atf4 protein, mouse, http://linkedlifedata.com/resource/pubmed/chemical/Core Binding Factor Alpha 1 Subunit, http://linkedlifedata.com/resource/pubmed/chemical/Ibsp protein, mouse, http://linkedlifedata.com/resource/pubmed/chemical/Integrin-Binding Sialoprotein, http://linkedlifedata.com/resource/pubmed/chemical/Isoenzymes, http://linkedlifedata.com/resource/pubmed/chemical/Mitogen-Activated Protein Kinase 9, http://linkedlifedata.com/resource/pubmed/chemical/Osteocalcin, http://linkedlifedata.com/resource/pubmed/chemical/Phosphoric Monoester Hydrolases, http://linkedlifedata.com/resource/pubmed/chemical/Protein Kinase Inhibitors, http://linkedlifedata.com/resource/pubmed/chemical/Runx2 protein, mouse, http://linkedlifedata.com/resource/pubmed/chemical/Sialoglycoproteins, http://linkedlifedata.com/resource/pubmed/chemical/Transcription Factors, http://linkedlifedata.com/resource/pubmed/chemical/osterix protein, mouse
pubmed:status
MEDLINE
pubmed:month
Mar
pubmed:issn
1523-4681
pubmed:author
pubmed:issnType
Electronic
pubmed:volume
24
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
398-410
pubmed:dateRevised
2010-11-18
pubmed:meshHeading
pubmed-meshheading:19016586-Activating Transcription Factor 4, pubmed-meshheading:19016586-Animals, pubmed-meshheading:19016586-Bone Matrix, pubmed-meshheading:19016586-Calcification, Physiologic, pubmed-meshheading:19016586-Cell Differentiation, pubmed-meshheading:19016586-Cell Line, pubmed-meshheading:19016586-Clone Cells, pubmed-meshheading:19016586-Core Binding Factor Alpha 1 Subunit, pubmed-meshheading:19016586-Gene Expression Regulation, pubmed-meshheading:19016586-Integrin-Binding Sialoprotein, pubmed-meshheading:19016586-Isoenzymes, pubmed-meshheading:19016586-Mice, pubmed-meshheading:19016586-Mice, Inbred C57BL, pubmed-meshheading:19016586-Mitogen-Activated Protein Kinase 9, pubmed-meshheading:19016586-Osteoblasts, pubmed-meshheading:19016586-Osteocalcin, pubmed-meshheading:19016586-Phosphoric Monoester Hydrolases, pubmed-meshheading:19016586-Protein Kinase Inhibitors, pubmed-meshheading:19016586-Sialoglycoproteins, pubmed-meshheading:19016586-Substrate Specificity, pubmed-meshheading:19016586-Transcription Factors
pubmed:year
2009
pubmed:articleTitle
JNK activity is essential for Atf4 expression and late-stage osteoblast differentiation.
pubmed:affiliation
Department of Oral Biochemistry, Field of Developmental Medicine, Graduate School of Medical and Dental Sciences, Kagoshima University, Kagoshima, Japan. tmatsugu@denta.hal.kagoshima-u.ac.jp
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't