Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
7
pubmed:dateCreated
2005-4-28
pubmed:abstractText
Interleukin-1 (IL-1) is a potent, proinflammatory cytokine, but local environmental factors in inflamed sites or in sepsis may affect cell metabolism and energetics, including the amplitude and duration of IL-1-induced signals, thereby leading to loss of tissue homeostasis. Currently, the mechanisms by which disruption of cell energetics affects inflammatory signaling are incompletely understood. Here, we examined the impact of cell energetics and mitochondrial function on the regulation of IL-1-induced Ca2+ signals and ERK activation in human gingival fibroblasts, cells that are important targets for IL-1-induced destruction of extracellular matrix in inflamed connective tissues. In untreated cells, IL-1 induced a prolonged increase of free intracellular calcium, which was required for ERK activation. Inhibition of cellular energetics by selective depolarization of mitochondria blocked Ca2+ uptake and almost completely abolished IL-1-induced cytosolic Ca2+ signals and ERK activation. IL-1 caused rapid Ca2+ release from the endoplasmic reticulum (ER), concomitant with mitochondrial Ca2+ uptake from ER and non-ER stores. Disruption of mitochondrial energetics abrogated IL-1 induced Ca2+ release from the ER but left other vital cellular functions intact. The negative effect of mitochondrial depolarization on ER release was bypassed by BAPTA/AM, indicating that mitochondrial Ca2+ buffering is the key mechanism in regulating ER release. Thus, in gingival fibroblasts, mitochondrial Ca2+ uptake is essential not only for shaping the kinetics and duration, but also the generation of, IL-1-induced Ca2+ signals. Consequently, mitochondria regulate key downstream effectors of IL-1, including MAP kinases.
pubmed:commentsCorrections
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
May
pubmed:issn
1530-6860
pubmed:author
pubmed:issnType
Electronic
pubmed:volume
19
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
837-9
pubmed:dateRevised
2009-11-19
pubmed:meshHeading
pubmed-meshheading:15728661-Adenosine Triphosphate, pubmed-meshheading:15728661-Calcium, pubmed-meshheading:15728661-Cells, Cultured, pubmed-meshheading:15728661-Chelating Agents, pubmed-meshheading:15728661-Egtazic Acid, pubmed-meshheading:15728661-Endoplasmic Reticulum, pubmed-meshheading:15728661-Energy Metabolism, pubmed-meshheading:15728661-Enzyme Activation, pubmed-meshheading:15728661-Extracellular Signal-Regulated MAP Kinases, pubmed-meshheading:15728661-Fibroblasts, pubmed-meshheading:15728661-Gingiva, pubmed-meshheading:15728661-Humans, pubmed-meshheading:15728661-Immunoblotting, pubmed-meshheading:15728661-Interleukin-1, pubmed-meshheading:15728661-Kinetics, pubmed-meshheading:15728661-Membrane Potentials, pubmed-meshheading:15728661-Mitochondria, pubmed-meshheading:15728661-Mitochondrial Membranes, pubmed-meshheading:15728661-Signal Transduction
pubmed:year
2005
pubmed:articleTitle
Mitochondrial function is a critical determinant of IL-1-induced ERK activation.
pubmed:affiliation
CIHR Group in Matrix Dynamics, University of Toronto, Toronto, Ontario M5S 3E2, Canada.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't