Arachidonate release consequent to bradykinin-stimulated phospholipid metabolism in dorsal root ganglion cells

Morell, Pierre; Allen, Ann C.; Gammon, Charles M.; Lyons, Susan A.

doi:10.1042/bst0190411

Cited by 2 publications

(2 citation statements)

References 5 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…1). In neuronal cells, upon receptor stimulation, either PLC or PLD can help supply AAcontaining lipids to the PG synthetic pathway (20). The studies presented in this work demonstrate that PLD and DAGL likely supply AA that is converted into PGE 2 in Francisella tularensis LVS-infected macrophages and that cPLA 2 contributes to the macrophage inflammatory response.…”

mentioning

confidence: 77%

“…These results point to an alternative pathway of AA liberation involving PLD and DAGL in F. tularensis LVS-infected macrophages. Alternative enzymatic pathways that liberate AA for conversion into prostanoids have been noted in neurons (20) but, as far as we know, not in macrophages. The immediate lipid product generated by PLD or DAGL activity is not AA.…”

Section: Discussionmentioning

confidence: 99%

See 1 more Smart Citation

Francisella tularensis LVS Induction of Prostaglandin Biosynthesis by Infected Macrophages Requires Specific Host Phospholipases and Lipid Phosphatases

et al. 2014

View full text Add to dashboard Cite

Francisella tularensis induces the synthesis of prostaglandin E 2 (PGE 2 ) by infected macrophages to alter host immune responses, thus providing a survival advantage to the bacterium. We previously demonstrated that PGE 2 synthesis by F. tularensis-infected macrophages requires cytosolic phospholipase A2 (cPLA 2 ), cyclooxygenase 2 (COX-2), and microsomal prostaglandin E synthase 1 (mPGES1). During inducible PGE 2 synthesis, cPLA 2 hydrolyzes arachidonic acid (AA) from cellular phospholipids to be converted to PGE 2 . However, in F. tularensis-infected macrophages we observed a temporal disconnect between Ser505-cPLA 2 phosphorylation (a marker of activation) and PGE 2 synthesis. These results suggested to us that cPLA 2 is not responsible for the liberation of AA to be converted into PGE 2 by F. tularensis-infected macrophages. Utilizing small-molecule inhibitors, we demonstrated that phospholipase D and diacylglycerol lipase were required for providing AA for PGE 2 biosynthesis. cPLA 2 , on the other hand, was required for macrophage cytokine responses to F. tularensis. We also demonstrated for the first time that lipin-1 and PAP2a contribute to macrophage inflammation in response to F. tularensis. Our results identify both an alternative pathway for inducible PGE 2 synthesis and a role for lipid-modifying enzymes in the regulation of macrophage inflammatory function.

show abstract

mentioning

confidence: 77%

Section: Discussionmentioning

confidence: 99%

Francisella tularensis LVS Induction of Prostaglandin Biosynthesis by Infected Macrophages Requires Specific Host Phospholipases and Lipid Phosphatases

et al. 2014

View full text Add to dashboard Cite

show abstract

Thyrotropin-releasing hormone and lysine-bradykinin stimulate arachidonate liberation from rat anterior pituitary cells through different mechanisms.

Judd

MacLeod

1992

Endocrinology

View full text Add to dashboard Cite

TRH and lysine-bradykinin (Lys-bradykinin) increase PRL release and arachidonate liberation from anterior pituitary cells. We investigated whether the arachidonate liberation stimulated by TRH and Lys-bradykinin originates in pituitary lactotropes and whether these events are accomplished through similar mechanisms. Lys-bradykinin and TRH rapidly (0.5 min) increased the intracellular [3H]arachidonate content of rat anterior pituitary cells. Lys-bradykinin also increased [3H]arachidonate liberation and PRL release from lactotrope-enriched pituitary cells, but not from a pituitary cell preparation with a diminished number of lactotropes. In contrast, TRH increased [3H]arachidonate liberation from both lactotrope-enriched and lactotrope-diminished preparations; this increased [3H]arachidonate liberation stimulated by TRH in the lactotrope-diminished cells may originate in the thyrotropes. The effects of TRH and Lys-bradykinin on [3H]arachidonate and [14C]stearate liberation in perfused pituitary cells also were determined. Both secretagogues increased arachidonate and stearate liberation in a biphasic manner, characterized by a transient spike, followed by a lower magnitude wave of fatty acid release. The spike phase produced by Lys-bradykinin was more pronounced than that produced by TRH. The calcium dependence of TRH- and Lys-bradykinin-stimulated arachidonate liberation also was investigated. Cobalt and the low calcium medium containing ionomycin were used to block the secretagogue-induced increase in intracellular calcium concentrations. These conditions blocked TRH-stimulated arachidonate liberation, but only marginally decreased Lys-bradykinin-stimulated arachidonate liberation, indicating that the two peptides act through different mechanisms. Therefore, TRH stimulation of arachidonate liberation is linked to an increase in intracellular calcium. In contrast, Lys-bradykinin increases arachidonate liberation through a calcium-independent intracellular mediator. This calcium-independent increase in arachidonate liberation may involve the bradykinin receptor being coupled directly to a phospholipase, a G-protein that provides a link between the bradykinin receptor and the phospholipases that liberate arachidonate, or bradykinin-induced activation of a protein kinase-C that activates the phospholipases and subsequently liberates arachidonate.

show abstract

Arachidonate release consequent to bradykinin-stimulated phospholipid metabolism in dorsal root ganglion cells

Cited by 2 publications

References 5 publications

Francisella tularensis LVS Induction of Prostaglandin Biosynthesis by Infected Macrophages Requires Specific Host Phospholipases and Lipid Phosphatases

Francisella tularensis LVS Induction of Prostaglandin Biosynthesis by Infected Macrophages Requires Specific Host Phospholipases and Lipid Phosphatases

Thyrotropin-releasing hormone and lysine-bradykinin stimulate arachidonate liberation from rat anterior pituitary cells through different mechanisms.

Contact Info

Product

Resources

About