Rapamycin Augments the NMDA-Mediated TNF Suppression of MRSA-Stimulated RAW264.7 Murine Macrophages

Background. Methicillin-resistant Staphylococcus aureus (MRSA) can stimulate massive cytokine release. Ketamine suppresses tumor necrosis factor (TNF) secretion by MRSA-stimulated RAW264.7 macrophages, and the mechanism likely involves N-methyl-D-aspartic acid (NMDA) receptor antagonism. The downst...

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Main Authors:	Spentzas, Thomas, Shappley, Rebekah K. H., Savorgnan, Fabio, Meals, Elizabeth, English, B. Keith
Format:	Online
Language:	English
Published:	Hindawi Publishing Corporation 2012
Online Access:	https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3474976/

id	pubmed-3474976
recordtype	oai_dc
spelling	pubmed-34749762012-10-23 Rapamycin Augments the NMDA-Mediated TNF Suppression of MRSA-Stimulated RAW264.7 Murine Macrophages Spentzas, Thomas Shappley, Rebekah K. H. Savorgnan, Fabio Meals, Elizabeth English, B. Keith Research Article Background. Methicillin-resistant Staphylococcus aureus (MRSA) can stimulate massive cytokine release. Ketamine suppresses tumor necrosis factor (TNF) secretion by MRSA-stimulated RAW264.7 macrophages, and the mechanism likely involves N-methyl-D-aspartic acid (NMDA) receptor antagonism. The downstream effects of NMDA-mediated TNF suppression, specifically the PI3K/Akt and mTOR modulation, have not been described. Methods. RAW264.7 cells were stimulated for 18 hrs with 105 to 107 CFU/mL inocula of either of two prototypical community-acquired- (CA-) MRSA isolates, USA300 strain LAC and USA400 strain MW2. Then we added the NMDA inhibitors ketamine or 2R-amino-5-phosphonopentanoate (AP5), NMDA substrate, LY294002, and rapamycin in various combinations. Results. NMDA inhibition suppressed TNF secretion by almost a third compared to the no-ketamine control. When NMDA substrate was added, the TNF secretion increased by 10%. Addition of LY294002 suppressed TNF production by macrophages by 20%. Rapamycin exhibited a concentration-dependent TNF induction-suppression response: induction at doses of 0.1 and 1 ng/mL and suppression at 10 and 100 ng/mL. Induction of TNF was abolished when LY294002 was added and the suppression became uniform. Ketamine-induced suppression of TNF secretion was intensified 10–15% when rapamycin was added, but not when LY294002 was added. Conclusion. These findings suggest that NMDA-induced TNF suppression can be augmented by concurrent mTOR inhibition. Hindawi Publishing Corporation 2012 2012-10-10 /pmc/articles/PMC3474976/ /pubmed/23094196 http://dx.doi.org/10.1155/2012/542727 Text en Copyright © 2012 Thomas Spentzas et al. https://creativecommons.org/licenses/by/3.0/ This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
repository_type	Open Access Journal
institution_category	Foreign Institution
institution	US National Center for Biotechnology Information
building	NCBI PubMed
collection	Online Access
language	English
format	Online
author	Spentzas, Thomas Shappley, Rebekah K. H. Savorgnan, Fabio Meals, Elizabeth English, B. Keith
spellingShingle	Spentzas, Thomas Shappley, Rebekah K. H. Savorgnan, Fabio Meals, Elizabeth English, B. Keith Rapamycin Augments the NMDA-Mediated TNF Suppression of MRSA-Stimulated RAW264.7 Murine Macrophages
author_facet	Spentzas, Thomas Shappley, Rebekah K. H. Savorgnan, Fabio Meals, Elizabeth English, B. Keith
author_sort	Spentzas, Thomas
title	Rapamycin Augments the NMDA-Mediated TNF Suppression of MRSA-Stimulated RAW264.7 Murine Macrophages
title_short	Rapamycin Augments the NMDA-Mediated TNF Suppression of MRSA-Stimulated RAW264.7 Murine Macrophages
title_full	Rapamycin Augments the NMDA-Mediated TNF Suppression of MRSA-Stimulated RAW264.7 Murine Macrophages
title_fullStr	Rapamycin Augments the NMDA-Mediated TNF Suppression of MRSA-Stimulated RAW264.7 Murine Macrophages
title_full_unstemmed	Rapamycin Augments the NMDA-Mediated TNF Suppression of MRSA-Stimulated RAW264.7 Murine Macrophages
title_sort	rapamycin augments the nmda-mediated tnf suppression of mrsa-stimulated raw264.7 murine macrophages
description	Background. Methicillin-resistant Staphylococcus aureus (MRSA) can stimulate massive cytokine release. Ketamine suppresses tumor necrosis factor (TNF) secretion by MRSA-stimulated RAW264.7 macrophages, and the mechanism likely involves N-methyl-D-aspartic acid (NMDA) receptor antagonism. The downstream effects of NMDA-mediated TNF suppression, specifically the PI3K/Akt and mTOR modulation, have not been described. Methods. RAW264.7 cells were stimulated for 18 hrs with 105 to 107 CFU/mL inocula of either of two prototypical community-acquired- (CA-) MRSA isolates, USA300 strain LAC and USA400 strain MW2. Then we added the NMDA inhibitors ketamine or 2R-amino-5-phosphonopentanoate (AP5), NMDA substrate, LY294002, and rapamycin in various combinations. Results. NMDA inhibition suppressed TNF secretion by almost a third compared to the no-ketamine control. When NMDA substrate was added, the TNF secretion increased by 10%. Addition of LY294002 suppressed TNF production by macrophages by 20%. Rapamycin exhibited a concentration-dependent TNF induction-suppression response: induction at doses of 0.1 and 1 ng/mL and suppression at 10 and 100 ng/mL. Induction of TNF was abolished when LY294002 was added and the suppression became uniform. Ketamine-induced suppression of TNF secretion was intensified 10–15% when rapamycin was added, but not when LY294002 was added. Conclusion. These findings suggest that NMDA-induced TNF suppression can be augmented by concurrent mTOR inhibition.
publisher	Hindawi Publishing Corporation
publishDate	2012
url	https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3474976/
_version_	1611917157962088448

Rapamycin Augments the NMDA-Mediated TNF Suppression of MRSA-Stimulated RAW264.7 Murine Macrophages

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