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Vimentin regulates activation of the NLRP3 inflammasome.

dos Santos G, Rogel MR, Baker MA, Troken JR, Urich D, Morales-Nebreda L, Sennello JA, Kutuzov MA, Sitikov A, Davis JM, Lam AP, Cheresh P, Kamp D, Shumaker DK, Budinger GR, Ridge KM - Nat Commun (2015)

Bottom Line: Activation of the NLRP3 inflammasome and subsequent maturation of IL-1β have been implicated in acute lung injury (ALI), resulting in inflammation and fibrosis.Furthermore, decreased active caspase-1 and IL-1β levels are observed in vitro in Vim(-/-) and vimentin-knockdown macrophages.This study provides insights into lung inflammation and fibrosis and suggests that vimentin may be a key regulator of the NLRP3 inflammasome.

View Article: PubMed Central - PubMed

Affiliation: Division of Pulmonary and Critical Care Medicine, Northwestern University, Chicago, Illinois 60611, USA.

ABSTRACT
Activation of the NLRP3 inflammasome and subsequent maturation of IL-1β have been implicated in acute lung injury (ALI), resulting in inflammation and fibrosis. We investigated the role of vimentin, a type III intermediate filament, in this process using three well-characterized murine models of ALI known to require NLRP3 inflammasome activation. We demonstrate that central pathophysiologic events in ALI (inflammation, IL-1β levels, endothelial and alveolar epithelial barrier permeability, remodelling and fibrosis) are attenuated in the lungs of Vim(-/-) mice challenged with LPS, bleomycin and asbestos. Bone marrow chimeric mice lacking vimentin have reduced IL-1β levels and attenuated lung injury and fibrosis following bleomycin exposure. Furthermore, decreased active caspase-1 and IL-1β levels are observed in vitro in Vim(-/-) and vimentin-knockdown macrophages. Importantly, we show direct protein-protein interaction between NLRP3 and vimentin. This study provides insights into lung inflammation and fibrosis and suggests that vimentin may be a key regulator of the NLRP3 inflammasome.

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Related in: MedlinePlus

Vimentin is required for ALI and inflammasome activation in response to LPS(A), Survival of WT and Vim-/- mice subjected to a lethal dose of LPS (80 mg/kg, intraperitoneally) was measured and compared. The survival curves were analyzed using the log rank test, which calculates the chi-square (X2) for each event time for each group and sums the results. The summed results for each group were added to derive the ultimate chi-square to compare the full curves of each group. The log rank test for the entire data set was P = 0.001. (B-F): WT and Vim-/- mice were challenged with a sublethal dose of LPS and markers of ALI were measured after 48 h, as assessed by H&E staining (scale bars, 200 μm) (B); by wet-to-dry lung weight ratio (C); and by protein content in the BALF (D). Inflammasome activation was measured by ELISA for caspase-1 (E) or IL-1β (F) in BALF from Vim-/- and WT mice. Data in B–E are from three independent experiments of n = 6–8 animals per group and presented as mean ± SD *P < 0.05, **P < 0.001, ***P<0.0001 relative to WT versus Vim-/-, by one way ANOVA with a correction provided by the Bonferroni multiple comparisons test.
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Figure 1: Vimentin is required for ALI and inflammasome activation in response to LPS(A), Survival of WT and Vim-/- mice subjected to a lethal dose of LPS (80 mg/kg, intraperitoneally) was measured and compared. The survival curves were analyzed using the log rank test, which calculates the chi-square (X2) for each event time for each group and sums the results. The summed results for each group were added to derive the ultimate chi-square to compare the full curves of each group. The log rank test for the entire data set was P = 0.001. (B-F): WT and Vim-/- mice were challenged with a sublethal dose of LPS and markers of ALI were measured after 48 h, as assessed by H&E staining (scale bars, 200 μm) (B); by wet-to-dry lung weight ratio (C); and by protein content in the BALF (D). Inflammasome activation was measured by ELISA for caspase-1 (E) or IL-1β (F) in BALF from Vim-/- and WT mice. Data in B–E are from three independent experiments of n = 6–8 animals per group and presented as mean ± SD *P < 0.05, **P < 0.001, ***P<0.0001 relative to WT versus Vim-/-, by one way ANOVA with a correction provided by the Bonferroni multiple comparisons test.

Mentions: Lipopolysaccharide (LPS) is a potent inducer of inflammation and a known NLRP3 inflammasome activator26-28. To determine whether vimentin is important in the inflammatory response, wild-type (WT) and vimentin knockout (Vim-/-) mice were subjected to a lethal dose of LPS, which induces both pro-inflammatory cytokine expression and a systemic inflammatory response that is associated with significant mortality. Wild-type mice displayed about a 3-fold increase in mortality compared with Vim-/- mice. Vim-/- mice had a median survival of 138 h, whereas WT animals had a median survival of ∼40 h (Figure 1A). Surviving Vim-/- mice exhibited mild lethargy, coat ruffling, febrile shaking, and eye watering but recovered by day 7.


Vimentin regulates activation of the NLRP3 inflammasome.

dos Santos G, Rogel MR, Baker MA, Troken JR, Urich D, Morales-Nebreda L, Sennello JA, Kutuzov MA, Sitikov A, Davis JM, Lam AP, Cheresh P, Kamp D, Shumaker DK, Budinger GR, Ridge KM - Nat Commun (2015)

Vimentin is required for ALI and inflammasome activation in response to LPS(A), Survival of WT and Vim-/- mice subjected to a lethal dose of LPS (80 mg/kg, intraperitoneally) was measured and compared. The survival curves were analyzed using the log rank test, which calculates the chi-square (X2) for each event time for each group and sums the results. The summed results for each group were added to derive the ultimate chi-square to compare the full curves of each group. The log rank test for the entire data set was P = 0.001. (B-F): WT and Vim-/- mice were challenged with a sublethal dose of LPS and markers of ALI were measured after 48 h, as assessed by H&E staining (scale bars, 200 μm) (B); by wet-to-dry lung weight ratio (C); and by protein content in the BALF (D). Inflammasome activation was measured by ELISA for caspase-1 (E) or IL-1β (F) in BALF from Vim-/- and WT mice. Data in B–E are from three independent experiments of n = 6–8 animals per group and presented as mean ± SD *P < 0.05, **P < 0.001, ***P<0.0001 relative to WT versus Vim-/-, by one way ANOVA with a correction provided by the Bonferroni multiple comparisons test.
© Copyright Policy
Related In: Results  -  Collection

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Figure 1: Vimentin is required for ALI and inflammasome activation in response to LPS(A), Survival of WT and Vim-/- mice subjected to a lethal dose of LPS (80 mg/kg, intraperitoneally) was measured and compared. The survival curves were analyzed using the log rank test, which calculates the chi-square (X2) for each event time for each group and sums the results. The summed results for each group were added to derive the ultimate chi-square to compare the full curves of each group. The log rank test for the entire data set was P = 0.001. (B-F): WT and Vim-/- mice were challenged with a sublethal dose of LPS and markers of ALI were measured after 48 h, as assessed by H&E staining (scale bars, 200 μm) (B); by wet-to-dry lung weight ratio (C); and by protein content in the BALF (D). Inflammasome activation was measured by ELISA for caspase-1 (E) or IL-1β (F) in BALF from Vim-/- and WT mice. Data in B–E are from three independent experiments of n = 6–8 animals per group and presented as mean ± SD *P < 0.05, **P < 0.001, ***P<0.0001 relative to WT versus Vim-/-, by one way ANOVA with a correction provided by the Bonferroni multiple comparisons test.
Mentions: Lipopolysaccharide (LPS) is a potent inducer of inflammation and a known NLRP3 inflammasome activator26-28. To determine whether vimentin is important in the inflammatory response, wild-type (WT) and vimentin knockout (Vim-/-) mice were subjected to a lethal dose of LPS, which induces both pro-inflammatory cytokine expression and a systemic inflammatory response that is associated with significant mortality. Wild-type mice displayed about a 3-fold increase in mortality compared with Vim-/- mice. Vim-/- mice had a median survival of 138 h, whereas WT animals had a median survival of ∼40 h (Figure 1A). Surviving Vim-/- mice exhibited mild lethargy, coat ruffling, febrile shaking, and eye watering but recovered by day 7.

Bottom Line: Activation of the NLRP3 inflammasome and subsequent maturation of IL-1β have been implicated in acute lung injury (ALI), resulting in inflammation and fibrosis.Furthermore, decreased active caspase-1 and IL-1β levels are observed in vitro in Vim(-/-) and vimentin-knockdown macrophages.This study provides insights into lung inflammation and fibrosis and suggests that vimentin may be a key regulator of the NLRP3 inflammasome.

View Article: PubMed Central - PubMed

Affiliation: Division of Pulmonary and Critical Care Medicine, Northwestern University, Chicago, Illinois 60611, USA.

ABSTRACT
Activation of the NLRP3 inflammasome and subsequent maturation of IL-1β have been implicated in acute lung injury (ALI), resulting in inflammation and fibrosis. We investigated the role of vimentin, a type III intermediate filament, in this process using three well-characterized murine models of ALI known to require NLRP3 inflammasome activation. We demonstrate that central pathophysiologic events in ALI (inflammation, IL-1β levels, endothelial and alveolar epithelial barrier permeability, remodelling and fibrosis) are attenuated in the lungs of Vim(-/-) mice challenged with LPS, bleomycin and asbestos. Bone marrow chimeric mice lacking vimentin have reduced IL-1β levels and attenuated lung injury and fibrosis following bleomycin exposure. Furthermore, decreased active caspase-1 and IL-1β levels are observed in vitro in Vim(-/-) and vimentin-knockdown macrophages. Importantly, we show direct protein-protein interaction between NLRP3 and vimentin. This study provides insights into lung inflammation and fibrosis and suggests that vimentin may be a key regulator of the NLRP3 inflammasome.

Show MeSH
Related in: MedlinePlus