Macropinocytosis of extracellular glutathione ameliorates tumor necrosis factor α release in activated macrophages.

A number of inflammatory lung diseases have abnormally low glutathione (GSH) levels in the airway fluids. Lung macrophages are common mediators of inflammation, make up the majority of cells that are found in the airway epithelial lining fluid (ELF), and are commonly elevated in many lung diseases....

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Main Authors: Neal S Gould, Elysia Min, Brian J Day
Format: Article
Language:English
Published: Public Library of Science (PLoS) 2011-01-01
Series:PLoS ONE
Online Access:http://europepmc.org/articles/PMC3185039?pdf=render
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author Neal S Gould
Elysia Min
Brian J Day
author_facet Neal S Gould
Elysia Min
Brian J Day
author_sort Neal S Gould
collection DOAJ
description A number of inflammatory lung diseases have abnormally low glutathione (GSH) levels in the airway fluids. Lung macrophages are common mediators of inflammation, make up the majority of cells that are found in the airway epithelial lining fluid (ELF), and are commonly elevated in many lung diseases. Several animal models with altered ELF GSH levels are associated with similar alterations in the intracellular GSH levels of bronchoalveolar lavage (BAL) cells. The possible mechanisms and outcomes for this association between ELF GSH levels and intracellular BAL cell GSH are unknown. To investigate these issues, macrophages were grown in media supplemented with 500 µM GSH. GSH supplementation resulted in a 2-3 fold increase in macrophage intracellular GSH levels. The increase in macrophage intracellular GSH levels was associated with a significant reduction in NF-κB nuclear translocation and tumor necrosis factor α (TNFα) release upon LPS stimulation. Furthermore, co-treatment of macrophages with GSH and inhibitors of GSH breakdown or synthesis did not block GSH accumulation. In contrast, treatment with cytochalasin D, an inhibitor of actin dependent endocytosis, and amiloride, an inhibitor of macropinocytosis blocked, at least in part, GSH uptake. Furthermore, using two cigarette smoke exposure paradigms that result in two different GSH levels in the ELF and thus in the BAL cells resulted in modulation of cytokine release when stimulated with LPS ex vivo. These data suggest that macrophages are able to utilize extracellular GSH which can then modulate inflammatory signaling in response to proinflammatory stimuli. This data also suggests the lung can modulate inflammatory responses triggered by proinflammatory stimuli by altering ELF GSH levels and may help explain the dysregulated inflammation associated with lung diseases that have low ELF GSH levels.
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spelling doaj.art-ec20df59af614b6488c0bc5e0b1027672022-12-22T01:53:29ZengPublic Library of Science (PLoS)PLoS ONE1932-62032011-01-01610e2570410.1371/journal.pone.0025704Macropinocytosis of extracellular glutathione ameliorates tumor necrosis factor α release in activated macrophages.Neal S GouldElysia MinBrian J DayA number of inflammatory lung diseases have abnormally low glutathione (GSH) levels in the airway fluids. Lung macrophages are common mediators of inflammation, make up the majority of cells that are found in the airway epithelial lining fluid (ELF), and are commonly elevated in many lung diseases. Several animal models with altered ELF GSH levels are associated with similar alterations in the intracellular GSH levels of bronchoalveolar lavage (BAL) cells. The possible mechanisms and outcomes for this association between ELF GSH levels and intracellular BAL cell GSH are unknown. To investigate these issues, macrophages were grown in media supplemented with 500 µM GSH. GSH supplementation resulted in a 2-3 fold increase in macrophage intracellular GSH levels. The increase in macrophage intracellular GSH levels was associated with a significant reduction in NF-κB nuclear translocation and tumor necrosis factor α (TNFα) release upon LPS stimulation. Furthermore, co-treatment of macrophages with GSH and inhibitors of GSH breakdown or synthesis did not block GSH accumulation. In contrast, treatment with cytochalasin D, an inhibitor of actin dependent endocytosis, and amiloride, an inhibitor of macropinocytosis blocked, at least in part, GSH uptake. Furthermore, using two cigarette smoke exposure paradigms that result in two different GSH levels in the ELF and thus in the BAL cells resulted in modulation of cytokine release when stimulated with LPS ex vivo. These data suggest that macrophages are able to utilize extracellular GSH which can then modulate inflammatory signaling in response to proinflammatory stimuli. This data also suggests the lung can modulate inflammatory responses triggered by proinflammatory stimuli by altering ELF GSH levels and may help explain the dysregulated inflammation associated with lung diseases that have low ELF GSH levels.http://europepmc.org/articles/PMC3185039?pdf=render
spellingShingle Neal S Gould
Elysia Min
Brian J Day
Macropinocytosis of extracellular glutathione ameliorates tumor necrosis factor α release in activated macrophages.
PLoS ONE
title Macropinocytosis of extracellular glutathione ameliorates tumor necrosis factor α release in activated macrophages.
title_full Macropinocytosis of extracellular glutathione ameliorates tumor necrosis factor α release in activated macrophages.
title_fullStr Macropinocytosis of extracellular glutathione ameliorates tumor necrosis factor α release in activated macrophages.
title_full_unstemmed Macropinocytosis of extracellular glutathione ameliorates tumor necrosis factor α release in activated macrophages.
title_short Macropinocytosis of extracellular glutathione ameliorates tumor necrosis factor α release in activated macrophages.
title_sort macropinocytosis of extracellular glutathione ameliorates tumor necrosis factor α release in activated macrophages
url http://europepmc.org/articles/PMC3185039?pdf=render
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