Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
10
pubmed:dateCreated
2007-9-17
pubmed:abstractText
Sodium-dependent vitamin C transporter (SVCT) 2-mediated L-ascorbic acid (AA) uptake is required in osteoblast-like differentiation of MC3T3-E1 cells, and prostaglandin E2 (PGE2) is among the most important local factors in bone formation, but the detailed mechanism by which PGE2 induces osteoblast differentiation remains obscure. We revealed that PGE2 induced AA uptake and osteoblast-like differential markers including alkaline phosphatase, collagen, osteocalcin expression, and mineralization in MC3T3-E1 cells. Inhibition of AA uptake by SVCT2 short isoform functioning as a dominant-negative mutant not only robustly attenuated PGE2-induced markers expression and mineralization, but also decreased their basal levels. However, upregulation of AA uptake resulted from PGE2-induced plasma membrane translocation of cytoplasm SVCT2, and this effect was abolished by pretreatment with EP4 receptor antagonist, AH-23848B or cAMP-dependent protein kinase A (PKA) inhibitor, H-89. Moreover, we showed SVCT2 physically interacted with PKA in immunoprecipitates, and PKA phosphorylated SVCT2 in vitro and in intact cells at Ser402 and Ser639 sites; however, mutation of Ser402 or/and Ser639 in SVCT2 severely diminished SVCT2 translocation in response to PGE2. Together, these results suggest that PGE2-induced SVCT2 plasma membrane translocation through EP4 receptor and subsequent phosphorylation of SVCT2 at Ser402 and Ser639 sites by PKA results in an increase of AA uptake and consequent promotion of osteoblast-like differentiation in MC3T3-E1 cells.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Oct
pubmed:issn
1350-9047
pubmed:author
pubmed:issnType
Print
pubmed:volume
14
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
1792-801
pubmed:dateRevised
2011-11-17
pubmed:meshHeading
pubmed:year
2007
pubmed:articleTitle
Activation of PKA and phosphorylation of sodium-dependent vitamin C transporter 2 by prostaglandin E2 promote osteoblast-like differentiation in MC3T3-E1 cells.
pubmed:affiliation
Zhejiang Respiratory Drugs Research Laboratory of State Foods and Drugs Administration of China, Medical School of Zhejiang University, No. 388 Yuhangtang Road, Hangzhou 310058, China.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't