Linked Life Data

18980246

Source:http://linkedlifedata.com/resource/pubmed/id/18980246

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
6
pubmed:dateCreated
2008-11-27
pubmed:abstractText
This study examined how L-leucine affected DNA synthesis and cell cycle regulatory protein expression in cultured primary chicken hepatocytes. L-Leucine promoted DNA synthesis in a dose- and time-dependent manner, with concomitant increases in cyclin D1 and cyclin E expression. Phospholipase C (PLC) and protein kinase C (PKC) mediated the L-leucine-induced increases in [3H]-thymidine incorporation and cyclin D1/CDK4 and cyclin E/CDK2 expression, as U73122 (a PLC inhibitor) or bisindolylmaleimide I (a PKC blocker) inhibited these effects. L-Leucine also increased PKC phosphorylation and intracellular Ca2+ levels. L-Leucine-mediated increases in [3H]-thymidine incorporation and cyclin/CDK expression were sensitive to LY 294002 (PI3K inhibitor), Akt inhibitor, PD 98059 (MEK inhibitor). It was also observed that L-leucine-induced increases of cyclin/CDK expression were inhibited by PI3K siRNA and ERK siRNA; L-leucine increased extracellular signal-regulated kinases 1/2 (ERK1/2) and Akt phosphorylation levels. Bisindolylmaleimide I attenuated L-leucine-induced phosphorylation of ERK1/2 but did not influence Akt phosphorylation, and PI3K siRNA and LY 294002 inhibited L-leucine-induced ERK1/2 phosphorylation, suggesting some cross-talk between the PKC and ERK1/2 or PI3K/Akt and ERK1/2 pathways. L-Leucine also increased the levels of phosphorylated molecular target of rapamycin (mTOR) and two of its targets, ribosomal protein S6 kinase (p70S6K), and 4E binding protein 1 (4E-BP1); furthermore, rapamycin (an mTOR inhibitor) blocked all of the mitogenic effects of L-leucine. In addition, Akt inhibitor blocked L-leucine-induced mTOR phosphorylation. In conclusion, L-leucine stimulated DNA synthesis and promoted cell cycle progression in primary cultured chicken hepatocytes through PKC, ERK1/2, PI3K/Akt, and mTOR.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Dec
pubmed:issn
1097-4644
pubmed:author
pubmed:issnType
Electronic
pubmed:day
15
pubmed:volume
105
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
1410-9
pubmed:dateRevised
2010-11-18
pubmed:meshHeading
pubmed:year
2008
pubmed:articleTitle
L-leucine increases [3H]-thymidine incorporation in chicken hepatocytes: involvement of the PKC, PI3K/Akt, ERK1/2, and mTOR signaling pathways.
pubmed:affiliation
Department of Veterinary Physiology, College of Veterinary Medicine, Biotherapy Human Resources Center (BK21), Chonnam National University, Gwangju 500-757, Korea.
pubmed:publicationType
Journal Article