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Annexin A1 released from apoptotic cells acts through formyl peptide receptors to dampen inflammatory monocyte activation via JAK/STAT/SOCS signalling.

Pupjalis D, Goetsch J, Kottas DJ, Gerke V, Rescher U - EMBO Mol Med (2011)

Bottom Line: Supernatants from apoptotic neutrophils or the annexin A1 peptidomimetic Ac2-26 significantly reduced IL-6 signalling and the release of TNF-α from endotoxin-challenged monocytes.Ac2-26 activated STAT3 in a JAK-dependent manner, resulting in upregulated SOCS3 levels, and depletion of SOCS3 reversed the Ac2-26-mediated inhibition of IL-6 signalling.This identifies annexin A1 as part of the anti-inflammatory pattern of apoptotic cells and links the activation of FPRs to established signalling pathways triggering anti-inflammatory responses.

View Article: PubMed Central - PubMed

Affiliation: Centre for Molecular Biology of Inflammation, and Interdisciplinary Clinical Research Centre, Institute of Medical Biochemistry, University of Muenster, Muenster, Germany.

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The anti-inflammatory effects of apoptotic cells are mediated through activation of JAK/STAT3 signallingApoptotic neutrophil culture supernatants (apopt. SN) suppress LPS-induced TNF-α release. Monocytes were pre-treated for 3 h with apopt. SN and subsequently stimulated with LPS for 6 h. TNF-α contents in the culture media were measured by TNF-α ELISA.Activation of STAT3. Monocytes were treated with culture supernatants from either fresh or apoptotic cells for 1 h. STAT3 activation was detected by immunoblotting of cell lysates with the anti-pTYR705-STAT3 antibody. Total STAT3 levels were visualized by reprobing the membrane using a STAT3 antibody.Involvement of JAK in the dampening of acute TNF-α release by apoptotic cell supernatants. Monocytes were treated with apopt. SN for 3 h with or without a prior incubation with JAK inhibitor 1 for 15 min. Monocytes were then stimulated with LPS for 6 h and TNF-α levels in the culture media were measured by ELISA.STAT3 dependence of the inhibitory effect of apoptotic cell supernatants. Monocytes were pre-treated with the specific STAT3 Inhibitor VI for 30 min prior to treatment with the apoptotic neutrophil supernatant for 3 h and the LPS stimulation for 6 h. ELISA data are presented as the mean ± SEM of four independent experiments. The significance of the differences was evaluated by one-way ANOVA followed by Bonferroni's Multiple Comparison Test. p-values < 0.05 were considered significant. In (B), a representative blot of three independent experiments is shown.
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fig01: The anti-inflammatory effects of apoptotic cells are mediated through activation of JAK/STAT3 signallingApoptotic neutrophil culture supernatants (apopt. SN) suppress LPS-induced TNF-α release. Monocytes were pre-treated for 3 h with apopt. SN and subsequently stimulated with LPS for 6 h. TNF-α contents in the culture media were measured by TNF-α ELISA.Activation of STAT3. Monocytes were treated with culture supernatants from either fresh or apoptotic cells for 1 h. STAT3 activation was detected by immunoblotting of cell lysates with the anti-pTYR705-STAT3 antibody. Total STAT3 levels were visualized by reprobing the membrane using a STAT3 antibody.Involvement of JAK in the dampening of acute TNF-α release by apoptotic cell supernatants. Monocytes were treated with apopt. SN for 3 h with or without a prior incubation with JAK inhibitor 1 for 15 min. Monocytes were then stimulated with LPS for 6 h and TNF-α levels in the culture media were measured by ELISA.STAT3 dependence of the inhibitory effect of apoptotic cell supernatants. Monocytes were pre-treated with the specific STAT3 Inhibitor VI for 30 min prior to treatment with the apoptotic neutrophil supernatant for 3 h and the LPS stimulation for 6 h. ELISA data are presented as the mean ± SEM of four independent experiments. The significance of the differences was evaluated by one-way ANOVA followed by Bonferroni's Multiple Comparison Test. p-values < 0.05 were considered significant. In (B), a representative blot of three independent experiments is shown.

Mentions: We first examined the effects of mediators released by apoptotic human neutrophils on the lipopolysaccharide (LPS, Calbiochem)-induced TNF-α release in monocytes. Human monocytes were pre-treated with culture supernatants obtained from apoptotic neutrophils, challenged with LPS and the levels of released TNF-α were then determined by enzyme-linked immunosorbent assay (ELISA; Immunotools). As expected, a substantial TNF-α release occurred in LPS-stimulated monocytes. However, when monocytes were pre-treated with apoptotic supernatant, a significant decrease in the amount of released TNF-α was observed (Fig 1A).


Annexin A1 released from apoptotic cells acts through formyl peptide receptors to dampen inflammatory monocyte activation via JAK/STAT/SOCS signalling.

Pupjalis D, Goetsch J, Kottas DJ, Gerke V, Rescher U - EMBO Mol Med (2011)

The anti-inflammatory effects of apoptotic cells are mediated through activation of JAK/STAT3 signallingApoptotic neutrophil culture supernatants (apopt. SN) suppress LPS-induced TNF-α release. Monocytes were pre-treated for 3 h with apopt. SN and subsequently stimulated with LPS for 6 h. TNF-α contents in the culture media were measured by TNF-α ELISA.Activation of STAT3. Monocytes were treated with culture supernatants from either fresh or apoptotic cells for 1 h. STAT3 activation was detected by immunoblotting of cell lysates with the anti-pTYR705-STAT3 antibody. Total STAT3 levels were visualized by reprobing the membrane using a STAT3 antibody.Involvement of JAK in the dampening of acute TNF-α release by apoptotic cell supernatants. Monocytes were treated with apopt. SN for 3 h with or without a prior incubation with JAK inhibitor 1 for 15 min. Monocytes were then stimulated with LPS for 6 h and TNF-α levels in the culture media were measured by ELISA.STAT3 dependence of the inhibitory effect of apoptotic cell supernatants. Monocytes were pre-treated with the specific STAT3 Inhibitor VI for 30 min prior to treatment with the apoptotic neutrophil supernatant for 3 h and the LPS stimulation for 6 h. ELISA data are presented as the mean ± SEM of four independent experiments. The significance of the differences was evaluated by one-way ANOVA followed by Bonferroni's Multiple Comparison Test. p-values < 0.05 were considered significant. In (B), a representative blot of three independent experiments is shown.
© Copyright Policy
Related In: Results  -  Collection

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getmorefigures.php?uid=PMC3377061&req=5

fig01: The anti-inflammatory effects of apoptotic cells are mediated through activation of JAK/STAT3 signallingApoptotic neutrophil culture supernatants (apopt. SN) suppress LPS-induced TNF-α release. Monocytes were pre-treated for 3 h with apopt. SN and subsequently stimulated with LPS for 6 h. TNF-α contents in the culture media were measured by TNF-α ELISA.Activation of STAT3. Monocytes were treated with culture supernatants from either fresh or apoptotic cells for 1 h. STAT3 activation was detected by immunoblotting of cell lysates with the anti-pTYR705-STAT3 antibody. Total STAT3 levels were visualized by reprobing the membrane using a STAT3 antibody.Involvement of JAK in the dampening of acute TNF-α release by apoptotic cell supernatants. Monocytes were treated with apopt. SN for 3 h with or without a prior incubation with JAK inhibitor 1 for 15 min. Monocytes were then stimulated with LPS for 6 h and TNF-α levels in the culture media were measured by ELISA.STAT3 dependence of the inhibitory effect of apoptotic cell supernatants. Monocytes were pre-treated with the specific STAT3 Inhibitor VI for 30 min prior to treatment with the apoptotic neutrophil supernatant for 3 h and the LPS stimulation for 6 h. ELISA data are presented as the mean ± SEM of four independent experiments. The significance of the differences was evaluated by one-way ANOVA followed by Bonferroni's Multiple Comparison Test. p-values < 0.05 were considered significant. In (B), a representative blot of three independent experiments is shown.
Mentions: We first examined the effects of mediators released by apoptotic human neutrophils on the lipopolysaccharide (LPS, Calbiochem)-induced TNF-α release in monocytes. Human monocytes were pre-treated with culture supernatants obtained from apoptotic neutrophils, challenged with LPS and the levels of released TNF-α were then determined by enzyme-linked immunosorbent assay (ELISA; Immunotools). As expected, a substantial TNF-α release occurred in LPS-stimulated monocytes. However, when monocytes were pre-treated with apoptotic supernatant, a significant decrease in the amount of released TNF-α was observed (Fig 1A).

Bottom Line: Supernatants from apoptotic neutrophils or the annexin A1 peptidomimetic Ac2-26 significantly reduced IL-6 signalling and the release of TNF-α from endotoxin-challenged monocytes.Ac2-26 activated STAT3 in a JAK-dependent manner, resulting in upregulated SOCS3 levels, and depletion of SOCS3 reversed the Ac2-26-mediated inhibition of IL-6 signalling.This identifies annexin A1 as part of the anti-inflammatory pattern of apoptotic cells and links the activation of FPRs to established signalling pathways triggering anti-inflammatory responses.

View Article: PubMed Central - PubMed

Affiliation: Centre for Molecular Biology of Inflammation, and Interdisciplinary Clinical Research Centre, Institute of Medical Biochemistry, University of Muenster, Muenster, Germany.

Show MeSH
Related in: MedlinePlus