Functional coupling of the NK1 tachykinin receptor to phospholipase D in chinese hamster ovary cells and astrocytoma cells.

Abstract

In [3H]myristic acid-prelabeled Chinese hamster ovary cells stably expressing the rat NK1 tachykinin receptor, the selective NK1 agonist [Pro9]substance P ([Pro9]SP) time and concentration dependently stimulated the formation of [3H]phosphatidylethanol in the presence of ethanol. This [Pro9]SP-induced activation of phospholipase D (PLD) was blocked by NK1 receptor antagonists and poorly or not mimicked by NK2 and NK3 agonists, respectively. In confirmation of previous observations, [Pro9]SP also stimulated the hydrolysis of phosphoinositides, the release of arachidonic acid, and the formation of cyclic AMP (cAMP). All these [Pro9]SP-evoked responses could be mimicked by aluminum fluoride, but they remained unaffected in cells pretreated with pertussis toxin, suggesting that a Gi/Go protein is not involved in these different signaling pathways. The activation of PLD by [Pro9]SP was sensitive to external calcium and required an active protein kinase C because the inhibition of this kinase (Ro 31-8220) or its down-regulation (long-term treatment with a phorbol ester) abolished the response. In contrast, a cAMP-dependent process was not involved in the activation of PLD because the [Pro9]SP-evoked response was neither affected by Rp-8-bromoadenosine 3',5'-cyclic monophosphorothioate nor mimicked by cAMP-generating compounds (cholera toxin or forskolin) or by 8-bromo-cyclic AMP. A functional coupling of NK1 receptors to PLD was also demonstrated in the human astrocytoma cell line U 373 MG stimulated by SP or [Pro9]SP. These results suggest that PLD activation could be an additional signaling pathway involved in the mechanism of action of SP in target cells expressing NK1 receptors.

• Authors: Y Torrens, J C Beaujouan, M Saffroy, J Glowinski, M Tencé
• Journal: Journal of neurochemistry (J Neurochem) Vol. 70 Issue 5 Pg. 2091-8 (May 1998) ISSN: 0022-3042 [Print] England
• PMID: 9572295 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Glycerophospholipids
• Phosphatidic Acids
• Phosphatidylcholines
• Receptors, Neurokinin-1
• Tachykinins
• phosphatidylethanol
• Myristic Acid
• substance P, Pro(9)-
• Substance P
• Cyclic AMP
• Protein Kinase C
• Phospholipase D
• GTP-Binding Proteins
• Calcium

Topics

• Animals
• Astrocytoma (metabolism, pathology)
• CHO Cells (metabolism)
• Calcium (pharmacology)
• Cricetinae
• Cyclic AMP (physiology)
• Enzyme Activation (drug effects)
• GTP-Binding Proteins (physiology)
• Glycerophospholipids
• Humans
• Myristic Acid (metabolism)
• Phosphatidic Acids (biosynthesis)
• Phosphatidylcholines (metabolism)
• Phospholipase D (metabolism)
• Protein Kinase C (physiology)
• Rats
• Receptors, Neurokinin-1 (metabolism)
• Substance P (analogs & derivatives, pharmacology)
• Tachykinins (pharmacology)
• Tumor Cells, Cultured