Arachidonate mobilization is coupled to depletion of intracellular calcium stores and influx of extracellular calcium in differentiated U937 cells

Rzigalinski, Beverly A.; Blackmore, Peter F.; Rosenthal, Miriam D.

doi:10.1016/0005-2760(95)00224-3

Cited by 38 publications

(27 citation statements)

References 45 publications

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“…Second, in order to function as CIF, arachidonic acid must first be released from its intracellular phospholipid storage pool through the action of PLA 2 , followed by metabolism via cytochrome P450. We have previously reported a coupling between cPLA 2 , arachidonic acid release, and depletion of calcium from intracellular stores (8). In the present report, we demonstrate that thapsigargin-stimulated arachidonic acid release is coupled to release of calcium from intracellular stores in the astrocytes.…”

Section: Discussionsupporting

confidence: 72%

“…It has been hypothesized that CIF represents a complex of several different biochemical components (4, 42). Our previous results suggest that the link to CIF requires the activation of cPLA 2 and release of arachidonic acid from cellular phospholipids in U937 cells (8). Other groups have reported similar correlations between arachidonic acid release and calcium influx (43,44).…”

Section: Discussionsupporting

confidence: 54%

“…Arachidonic Acid Release-Arachidonic acid release was measured as described previously (8,26). Briefly, 1 ϫ 10 6 cells grown in a 25-mm diameter well were radiolabeled by addition of 0.5 Ci of […”

Section: ϩmentioning

confidence: 99%

See 2 more Smart Citations

Calcium Influx Factor, Further Evidence It Is 5,6-Epoxyeicosatrienoic Acid

Rzigalinski

Willoughby

Hoffman

et al. 1999

Journal of Biological Chemistry

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129

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We present evidence in astrocytes that 5,6-epoxyeicosatrienoic acid, a cytochrome P450 epoxygenase metabolite of arachidonic acid, may be a component of calcium influx factor, the elusive link between release of Ca 2؉ from intracellular stores and capacitative Ca 2؉ influx. Capacitative influx of extracellular Ca 2؉ was inhibited by blockade of the two critical steps in epoxyeicosatrienoic acid synthesis: release of arachidonic acid from phospholipid stores by cytosolic phospholipase A 2 and cytochrome P450 metabolism of arachidonic acid. AAOCF 3 , which inhibits cytosolic phospholipase A 2 , blocked thapsigargin-stimulated release of arachidonic acid as well as thapsigargin-stimulated elevation of intracellular free calcium. Inhibition of P450 arachidonic acid metabolism with SKF525A, econazole, or N-methylsulfonyl-6-(2-propargyloxyphenyl)hexanamide, a substrate inhibitor of P450 arachidonic acid metabolism, also blocked thapsigargin-stimulated Ca 2؉ influx. Nanoto picomolar 5,6-epoxyeicosatrienoic acid induced [Ca 2؉ ] i elevation consistent with capacitative Ca 2؉ influx. We have previously shown that 5,6-epoxyeicosatrienoic acid is synthesized and released by astrocytes. When 5,6-epoxyeicosatrienoic acid was applied to the rat brain surface, it induced vasodilation, suggesting that calcium influx factor may also serve a paracrine function. In summary, our results suggest that 5,6-epoxyeicosatrienoic acid may be a component of calcium influx factor and may participate in regulation of cerebral vascular tone.

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Section: Discussionsupporting

confidence: 72%

Section: Discussionsupporting

confidence: 54%

See 1 more Smart Citation

Calcium Influx Factor, Further Evidence It Is 5,6-Epoxyeicosatrienoic Acid

Rzigalinski

Willoughby

Hoffman

et al. 1999

Journal of Biological Chemistry

Self Cite

129

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“…There is direct evidence that AA, the substrate for EETs, is mobilized by store depletion (29,75,76). Furthermore, CCE was inhibited by specific inhibitors of the cytosolic phospholipase A 2 that may be responsible for AA release (29,75,76). Upon agonist stimulation, cytosolic phospholipase A 2 may translocate to the membranes of the ER and nuclear envelope (77).…”

Section: Discussionmentioning

confidence: 99%

Calcium Influx Factor from Cytochrome P-450 Metabolism and Secretion-like Coupling Mechanisms for Capacitative Calcium Entry in Corneal Endothelial Cells

Xie

Zhang

Zhai

et al. 2002

Journal of Biological Chemistry

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“…Indeed, arachidonate mobilization was recently demonstrated to be coupled to activation of the capacitive pathway of calcium entry (68), suggesting that cPLA 2 may promote its own negative control by increasing [Ca 2ϩ ] i to levels necessary for annexin V inhibitory effect.…”

Section: Discussionmentioning

confidence: 99%

Inhibition of Cytosolic Phospholipase A2 by Annexin V in Differentiated Permeabilized HL-60 Cells

Mira

Dubois

Oudinet

et al. 1997

Journal of Biological Chemistry

107

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Annexin V belongs to a family of proteins that interact with phospholipids in a Ca 2؉ -dependent manner. This protein has been demonstrated to have anti-phospholipase A 2 activity. However, this effect has never yet been reported with the 85-kDa cytosolic PLA 2 (cPLA 2 ). We studied, in a model of differentiated and streptolysin O-permeabilized HL-60 cells, the effect of annexin V on cPLA 2 activity after stimulation by calcium, GTP␥S (guanosine 5-O-(3-thiotriphosphate)), formyl-Met-LeuPhe, or phorbol 12-myristate 13-acetate. Both recombinant and human placental purified annexin V inhibit cPLA 2 activity whatever the stimulus used. The decrease of arachidonic acid release is of 40 and 50%, respectively, at [Ca 2؉ ] of 3 and 10 M. The mechanism of inhibition was also analyzed. cPLA 2 requires calcium and protein kinase C (PKC) or mitogen-activated protein kinase phosphorylation for its activation. As annexin V was shown to be an endogenous inhibitor of PKC, PKC-stimulated cPLA 2 activity was analyzed. Using GF109203x, a specific PKC inhibitor, we demonstrated that this pathway is of minor importance in our model. cPLA 2 inhibition by annexin V is not linked to PKC inhibition. To test the hypothesis of phospholipid depletion, mutants of annexin V were constructed using mutagenesis directed to Ca 2؉ site. We demonstrate that the Ca 2؉ site located in domain I is necessary for the inhibitory effect of annexin V on cPLA 2 activity. The site in domain IV is also involved but with less efficiency. In contrast, mutations in site II and III do not modify this effect. Moreover, annexin V mutated on all sites does not inhibit cPLA 2 . Thus, we propose a predominant role of module (I/IV) in the biological action of annexin V, which, in physiological conditions, may control cPLA 2 activity by depletion of the phospholipid substrate.

show abstract

Arachidonate mobilization is coupled to depletion of intracellular calcium stores and influx of extracellular calcium in differentiated U937 cells

Cited by 38 publications

References 45 publications

Calcium Influx Factor, Further Evidence It Is 5,6-Epoxyeicosatrienoic Acid

Calcium Influx Factor, Further Evidence It Is 5,6-Epoxyeicosatrienoic Acid

Calcium Influx Factor from Cytochrome P-450 Metabolism and Secretion-like Coupling Mechanisms for Capacitative Calcium Entry in Corneal Endothelial Cells

Inhibition of Cytosolic Phospholipase A2 by Annexin V in Differentiated Permeabilized HL-60 Cells

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