Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
12
pubmed:dateCreated
2006-11-20
pubmed:abstractText
Cell dysfunction and death induced by lipid accumulation in nonadipose tissues, or lipotoxicity, may contribute to the pathogenesis of obesity and type 2 diabetes. However, the mechanisms leading to lipotoxic cell death are poorly understood. We recently reported that, in Chinese hamster ovary (CHO) cells and in H9c2 cardiomyoblasts, lipid overload induced by incubation with 500 muM palmitate leads to intracellular accumulation of reactive oxygen species, which subsequently induce endoplasmic reticulum (ER) stress and cell death. Here, we show that palmitate also impairs ER function through a more direct mechanism. Palmitate was rapidly incorporated into saturated phospholipid and triglyceride species in microsomal membranes of CHO cells. The resulting membrane remodeling was associated with dramatic dilatation of the ER and redistribution of protein-folding chaperones to the cytosol within 5 h, indicating compromised ER membrane integrity. Increasing beta-oxidation, through the activation of AMP-activated protein kinase, decreased palmitate incorporation into microsomes, decreased the escape of chaperones to the cytosol, and decreased subsequent caspase activation and cell death. Thus, palmitate rapidly increases the saturated lipid content of the ER, leading to compromised ER morphology and integrity, suggesting that impairment of the structure and function of this organelle is involved in the cellular response to fatty acid overload.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Dec
pubmed:issn
0022-2275
pubmed:author
pubmed:issnType
Print
pubmed:volume
47
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
2726-37
pubmed:dateRevised
2007-12-3
pubmed:meshHeading
pubmed:year
2006
pubmed:articleTitle
Disruption of endoplasmic reticulum structure and integrity in lipotoxic cell death.
pubmed:affiliation
Center for Cardiovascular Research, Division of Cardiology, Department of Internal Medicine, Washington University School of Medicine, St. Louis, MO 63110, USA.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't, Research Support, N.I.H., Extramural