Linked Life Data

17513494

Source:http://linkedlifedata.com/resource/pubmed/id/17513494

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
3
pubmed:dateCreated
2007-9-6
pubmed:abstractText
Ischemia-reperfusion-induced Ca(2+) overload results in activation of calpain-1 in the heart. Calpain-dependent proteolysis contributes to myocardial dysfunction and cell death. Previously, preischemic treatment with low doses of H(2)O(2) was shown to improve postischemic function and reduce myocardial infarct size. Our aim was to determine the mechanism by which H(2)O(2) protects the heart. We hypothesized that H(2)O(2) causes the activation of p38 MAPK which initiates translocation of heat shock protein 25/27 (HSP25/27) to the myofilament Z disk. We further hypothesized that HSP25/27 shields structural proteins, particularly desmin, from calpain-induced proteolysis. To address this hypothesis, we first determined that an ischemia-reperfusion-induced decrease in desmin content could be blocked by H(2)O(2) pretreatment of hearts from rats. We next determined that ventricular myocytes that underwent Ca(2+) overload also demonstrated a calpain-dependent disruption of desmin that could be reduced by H(2)O(2)/p38 MAPK activation. Furthermore, myocytes acutely treated with H(2)O(2) exhibited a decrease in cleavage of desmin upon exposure to exogenous calpain-1 compared with myocytes not pretreated with H(2)O(2). The H(2)O(2)-induced attenuation of desmin degradation by calpain-1 was blocked by inhibition of p38 MAPK. In a final series of experiments, we demonstrated that cardiac myofilaments exposed to recombinant phosphorylated HSP27, but not nonphosphorylated HSP27, had a significant reduction in the calpain-induced degradation of desmin compared with non-HSP27-treated myofilaments. These findings are consistent with the hypothesis that H(2)O(2)-induced activation of p38 MAPK and subsequent HSP25/27 translocation attenuates desmin degradation brought about by calpain-1 activation in ischemia-reperfused hearts.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Sep
pubmed:issn
0363-6135
pubmed:author
pubmed:issnType
Print
pubmed:volume
293
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
H1518-25
pubmed:dateRevised
2011-11-17
pubmed:meshHeading
pubmed:year
2007
pubmed:articleTitle
H2O2 activation of HSP25/27 protects desmin from calpain proteolysis in rat ventricular myocytes.
pubmed:affiliation
Department of Physiology, University of Tennessee Health Science Center, 894 Union Ave., Memphis, TN 38163, USA.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't, Research Support, N.I.H., Extramural