Prostacyclin production by confluent and non-confluent human endothelial cells in culture

Evans, Cameron; Billington, David C.; McEVOY, Finbar A.

doi:10.1016/0262-1746(84)90209-9

Cited by 22 publications

(14 citation statements)

References 23 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…7). This represents a novel molecular switch for the control of endothelial prostaglandin generation and accounts for earlier observations that confluent endothelial cells generate lower levels of prostaglandins compared with nonconfluent endothelial cells (14,15). In this study, we describe the Ca 2ϩ -induced association of cPLA 2 ␣ with the ER/ERGIC of nonconfluent HUVECs.…”

Section: Discussionmentioning

confidence: 82%

See 1 more Smart Citation

The Confluence-dependent Interaction of Cytosolic Phospholipase A2-α with Annexin A1 Regulates Endothelial Cell Prostaglandin E2 Generation

Herbert

Odell

Ponnambalam

et al. 2007

Journal of Biological Chemistry

View full text Add to dashboard Cite

The regulated generation of prostaglandins from endothelial cells is critical to vascular function. Here we identify a novel mechanism for the regulation of endothelial cell prostaglandin generation. Cytosolic phospholipase A 2 -␣ (cPLA 2 ␣) cleaves phospholipids in a Ca 2؉ -dependent manner to yield free arachidonic acid and lysophospholipid. Arachidonic acid is then converted into prostaglandins by the action of cyclooxygenase enzymes and downstream synthases. By previously undefined mechanisms, nonconfluent endothelial cells generate greater levels of prostaglandins than confluent cells. Here we demonstrate that Ca 2؉-independent association of cPLA 2 ␣ with the Golgi apparatus of confluent endothelial cells correlates with decreased prostaglandin synthesis. Golgi association blocks arachidonic acid release and prevents functional coupling between cPLA 2 ␣ and COX-mediated prostaglandin synthesis. When inactivated at the Golgi apparatus of confluent endothelial cells, cPLA 2 ␣ is associated with the phospholipid-binding protein annexin A1. Furthermore, the siRNA-mediated knockdown of endogenous annexin A1 significantly reverses the inhibitory effect of confluence on endothelial cell prostaglandin generation. Thus the confluence-dependent interaction of cPLA 2 ␣ and annexin A1 at the Golgi acts as a novel molecular switch controlling cPLA 2 ␣ activity and endothelial cell prostaglandin generation.

show abstract

Section: Discussionmentioning

confidence: 82%

“…(14,15). We predicted that the sequestration of cPLA 2 ␣ at confluence would be important to the control of prostaglandin generation.…”

Section: E)mentioning

confidence: 99%

The Confluence-dependent Interaction of Cytosolic Phospholipase A2-α with Annexin A1 Regulates Endothelial Cell Prostaglandin E2 Generation

Herbert

Odell

Ponnambalam

et al. 2007

Journal of Biological Chemistry

View full text Add to dashboard Cite

show abstract

“…Some investigators have reported that stimulated production of prostacyclin by endothelial cells changes with increasing time in culture or with repeated passage of the cells although the pattern of change is variable from study to study (1,(14)(15)(16). To clarify this, we first examined the stimulated production of prostacyclin (PGI2), the major arachidonic acid metabolite, by endothelial cells as they progressed from an actively dividing, preconfluent state to a contact-inhibited monolayer.…”

Section: Resultsmentioning

confidence: 99%

“…Many phenotypic changes occur in cultured endothelial cells as they progress from an actively dividing, preconfluent cell to a contact-inhibited monolayer. Several studies have shown that the ability of endothelial cells to produce PGI2 changes as the cells are maintained in culture, particularly with multiple passes (1,(14)(15)(16). Thus, there is evidence that arachidonic acid metabolism is in some way related to the growth state of endothelial cells in culture.…”

Section: Introductionmentioning

confidence: 99%

Proliferation-dependent changes in release of arachidonic acid from endothelial cells.

Whatley¹,

Satoh²,

Zimmerman³

et al. 1994

J. Clin. Invest.

View full text Add to dashboard Cite

Stimulation of endothelial cells resulted in release of arachidonic acid from phospholipids. The magnitude of this response decreased as the cells became confluent and the change coincided with a decrease in the percentage of cells in growth phases (G2 + M); this was not a consequence of time in culture or a factor in the growth medium. Preconfluent cells released 30% of arachidonic acid; confluent cells released only 6%. The decreasing release of arachidonic acid was demonstrated using metabolic labeling, mass measurements of arachidonic acid, and measurement of PGI2. The decrease was not due to a changing pool of arachidonic acid, and mass measurements showed no depletion of arachidonic acid. Release from each phospholipid and from each phospholipid class decreased with confluence. Conversion of confluent cells to the proliferative phenotype by mechanical wounding of the monolayer caused increased release of arachidonic acid. Potential mechanisms for these changes were investigated using assays of phospholipase activity. Phospholipase A2 activity changed in concert with the alteration in release, a consequence of changes in phosphorylation of the enzyme. The increased release of arachidonic acid from preconfluent, actively dividing cells may have important physiologic implications and may help elucidate mechanisms regulating release of arachidonic acid. (J. Clin.

show abstract

“…These studies indicate that the production of eicosanoids is greater in the exponential phase of growth as compared with confluent monolayers (2). Confluent cells do not make PGI2 continuously but react to stimulation with transiently enhanced product formation (18). Interestingly, PGI2 production by non-confluent cultures decreases as cell density increases (18) which eventually is due to release of a synthesis inhibitor, such as PGI2 (1).…”

Section: Regulation Of Eicosanoid Formation In Endothelial Cellsmentioning

confidence: 99%

Prostaglandins, other eicosanoids and endothelial cells

Schrör

1985

Basic Res Cardiol

View full text Add to dashboard Cite

Endothelial cells are an important source of eicosanoid formation in the cardiovascular systems. All major pathways of eicosanoid production have been demonstrated in endothelial cells, yielding significant amounts of prostacyclin (PGI2), PGE2, PGF2 alpha, thromboxane A2, leukotrienes and a number of hydroxy fatty acids. The regulation of eicosanoid formation by endothelial cells is poorly understood. There is evidence that precursors, such as arachidonic acid or prostaglandin endoperoxides, may also be provided by other cell types. Endothelial cell-derived eicosanoids are involved in the regulation of local vessel tone, intravascular platelet activation, cell locomotion and, eventually, cell proliferation. Most of the available information considers PGI2. This compound is the quantitatively dominating eicosanoid in endothelial cells. Major actions of PGI2 include inhibition of platelet activation and aggregation, relaxation of arterial vessels and inhibition of growth-factor release. There is probably a tight interaction with other biologically active mediators which needs further evaluation. This also applies to the clinical significance of eicosanoid-related pathways for the mechanism of action of cardiovascular drugs, such as organic nitrates or acetylsalicylic acid. The unique property of the eicosanoid system to become activated only in response to stimulation, the local nature of this reaction, the multiplicity of products formed and the short half-time of most of them are currently the most significant obstacles to define the role of endothelial cell-derived eicosanoids in clinical practice.

show abstract

Prostacyclin production by confluent and non-confluent human endothelial cells in culture

Cited by 22 publications

References 23 publications

The Confluence-dependent Interaction of Cytosolic Phospholipase A2-α with Annexin A1 Regulates Endothelial Cell Prostaglandin E2 Generation

The Confluence-dependent Interaction of Cytosolic Phospholipase A2-α with Annexin A1 Regulates Endothelial Cell Prostaglandin E2 Generation

Proliferation-dependent changes in release of arachidonic acid from endothelial cells.

Prostaglandins, other eicosanoids and endothelial cells

Contact Info

Product

Resources

About