Linked Life Data

19380828

Source:http://linkedlifedata.com/resource/pubmed/id/19380828

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
9
pubmed:dateCreated
2009-4-21
pubmed:abstractText
High-mobility group box 1 protein (HMGB1) has been studied as a key mediator of inflammatory diseases, including sepsis. Regulating secretion is important in the control of HMGB1-mediated inflammation. Previously, it was shown that HMGB1 needs to be phosphorylated for secretion. In this study, we show that HMGB1 is phosphorylated by the classical protein kinase C (cPKC) and is secreted by a calcium-dependent mechanism. For this study, RAW264.7 cells and human peripheral blood monocytes were treated with PI3K inhibitors wortmannin, LY294002, and ZSTK474, resulting in inhibition of LPS-stimulated HMGB1 secretion, whereas inhibitors of NF-kappaB and MAPKs p38 and ERK showed no inhibition. Akt inhibitor IV and mammalian target of rapamycin inhibitor rapamycin did not inhibit HMGB1 secretion. However, the PKC inhibitors Gö6983 (broad-spectrum PKC), Gö6976 (cPKC), and Ro-31-7549 (cPKC) and phosphoinositide-dependent kinase 1 inhibitor, which results in protein kinase C (PKC) inhibition, inhibited LPS-stimulated HMGB1 secretion. PKC activators, PMA and bryostatin-1, enhanced HMGB1 secretion. In an in vitro kinase assay, HMGB1 was phosphorylated by recombinant cPKC and by purified nuclear cPKC from LPS-stimulated RAW264.7 cells, but not by casein kinase II or cdc2. HMGB1 secretion was also induced by the calcium ionophore A23187 and inhibited by the Ca(2+) chelators BAPTA-AM and EGTA. These findings support a role for Ca(2+)-dependent PKC in HMGB1 secretion. Thus, we propose that cPKC is an effector kinase of HMGB1 phosphorylation in LPS-stimulated monocytes and PI3K-phosphoinositide-dependent kinase 1 may act in concert to control HMGB1 secretion independent of the NF-kappaB, p38, and ERK pathways.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
AIM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
May
pubmed:issn
1550-6606
pubmed:author
pubmed:issnType
Electronic
pubmed:day
1
pubmed:volume
182
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
5800-9
pubmed:meshHeading
pubmed:year
2009
pubmed:articleTitle
HMGB1 is phosphorylated by classical protein kinase C and is secreted by a calcium-dependent mechanism.
pubmed:affiliation
Department of Microbiology, Brain Korea 21 Project for Medical Science, Yonsei University College of Medicine, Seoul, Korea.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't