scholarly journals Non-Genomic AhR-Signaling Modulates the Immune Response in Endotoxin-Activated Macrophages After Activation by the Environmental Stressor BaP

2021 ◽  
Vol 12 ◽  
Author(s):  
Henning Großkopf ◽  
Katharina Walter ◽  
Isabel Karkossa ◽  
Martin von Bergen ◽  
Kristin Schubert

Emerging studies revealed that the Aryl hydrocarbon receptor (AhR), a receptor sensing environmental contaminants, is executing an immunomodulatory function. However, it is an open question to which extent this is achieved by its role as a transcription factor or via non-genomic signaling. We utilized a multi-post-translational modification-omics approach to examine non-genomic AhR-signaling after activation with endogenous (FICZ) or exogenous (BaP) ligand in endotoxin-activated (LPS) monocyte-derived macrophages. While AhR activation affected abundances of few proteins, regulation of ubiquitination and phosphorylation were highly pronounced. Although the number and strength of effects depended on the applied AhR-ligand, both ligands increased ubiquitination of Rac1, which participates in PI3K/AKT-pathway-dependent macrophage activation, resulting in a pro-inflammatory phenotype. In contrast, co-treatment with ligand and LPS revealed a decreased AKT activity mediating an anti-inflammatory effect. Thus, our data show an immunomodulatory effect of AhR activation through a Rac1ubiquitination-dependent mechanism that attenuated AKT-signaling, resulting in a mitigated inflammatory response.

2010 ◽  
Vol 2010 ◽  
pp. 1-10 ◽  
Author(s):  
Cinthia C. Stempin ◽  
Laura R. Dulgerian ◽  
Vanina V. Garrido ◽  
Fabio M. Cerban

A type 1 cytokine-dependent proinflammatory response inducing classically activated macrophages (CaMϕs) is crucial for parasite control during protozoan infections but can also contribute to the development of immunopathological disease symptoms. Type 2 cytokines such as IL-4 and IL-13 antagonize CaMϕs inducing alternatively activated macrophages (AaMϕs) that upregulate arginase-1 expression. During several infections, induction of arginase-1-macrophages was showed to have a detrimental role by limiting CaMϕ-dependent parasite clearance and promoting parasite proliferation. Additionally, the role of arginase-1 in T cell suppression has been explored recently. Arginase-1 can also be induced by IL-10 and transforming growth factor-β(TGF-β) or even directly by parasites or parasite components. Therefore, generation of alternative activation states of macrophages could limit collateral tissue damage because of excessive type 1 inflammation. However, they affect disease outcome by promoting parasite survival and proliferation. Thus, modulation of macrophage activation may be instrumental in allowing parasite persistence and long-term host survival.


2010 ◽  
Vol 107 (46) ◽  
pp. 19961-19966 ◽  
Author(s):  
N. T. Nguyen ◽  
A. Kimura ◽  
T. Nakahama ◽  
I. Chinen ◽  
K. Masuda ◽  
...  

2019 ◽  
Vol 476 (1) ◽  
pp. 85-99 ◽  
Author(s):  
Ivana Y. Quiroga ◽  
Magali Pellon-Maison ◽  
Amanda L. Suchanek ◽  
Rosalind A. Coleman ◽  
Maria R. Gonzalez-Baro

AbstractMacrophage classical M1 activation via TLR4 triggers a variety of responses to achieve the elimination of foreign pathogens. During this process, there is also an increase in lipid droplets which contain large quantities of triacylglycerol (TAG) and phospholipid (PL). The functional consequences of this increment in lipid mass are poorly understood. Here, we studied the contribution of glycerolipid synthesis to lipid accumulation, focusing specifically on the first and rate-limiting enzyme of the pathway: glycerol-3-phosphate acyltransferase (GPAT). Using bone marrow-derived macrophages (BMDMs) treated with Kdo2-lipid A, we showed that glycerolipid synthesis is induced during macrophage activation. GPAT4 protein level and GPAT3/GPAT4 enzymatic activity increase during this process, and these two isoforms were required for the accumulation of cell TAG and PL. The phagocytic capacity of Gpat3−/− and Gpat4−/− BMDM was impaired. Additionally, inhibiting fatty acid β-oxidation reduced phagocytosis only partially, suggesting that lipid accumulation is not necessary for the energy requirements for phagocytosis. Finally, Gpat4−/− BMDM expressed and released more pro-inflammatory cytokines and chemokines after macrophage activation, suggesting a role for GPAT4 in suppressing inflammatory responses. Together, these results provide evidence that glycerolipid synthesis directed by GPAT4 is important for the attenuation of the inflammatory response in activated macrophages.


2019 ◽  
Vol 11 (16) ◽  
pp. 2081-2094 ◽  
Author(s):  
Tingting Guo ◽  
Zhenzhong Su ◽  
Qi Wang ◽  
Wei Hou ◽  
Junyao Li ◽  
...  

Aim: Thus far, the anti-inflammatory effect of vanillin in acute lung injury (ALI) has not been studied. This study aimed to investigate the effect of vanillin in lipopolysaccharide (LPS)-induced ALI. Results & methodology: Our study detected the anti-inflammatory effects of vanillin by ELISA and western blot, respectively. Pretreatment of mice with vanillin significantly attenuated LPS-stimulated lung histopathological changes, myeloperoxidase activity and expression levels of proinflammatory cytokines by inhibiting the phosphorylation activities of ERK1/2, p38, AKT and NF-κB p65. In addition, vanillin inhibited LPS-induced TNF-α and IL-6 expression in RAW264.7 cells via ERK1/2, p38 and NF-κB signaling. Conclusion: Vanillin can inhibit macrophage activation and lung inflammation, which suggests new insights for clinical treatment of ALI.


Stroke ◽  
2020 ◽  
Vol 51 (Suppl_1) ◽  
Author(s):  
Jonathan H DeLong ◽  
Sofia Velazquez ◽  
Margaret J Landreneau ◽  
Lauren H Sansing

Introduction: In response to intracerebral hemorrhage (ICH), monocytes are recruited to the brain parenchyma, where they differentiate into macrophages and contribute to a pathological inflammatory response. However, by day 3 after ICH, brain macrophages have adopted a more reparative phenotype and are important for clearance of apoptotic cells and recovery. The signals that control this inflammatory to reparative differentiation are incompletely understood, but cholesterol has been found to limit macrophage activation in multiple systems. The brain has the highest cholesterol content of any organ and we hypothesized that cholesterol uptake by macrophages limits inflammation and promotes the development of reparative macrophages following ICH. Methods and Results: Murine bone marrow-derived macrophages were stimulated with a cocktail of thrombin, S100A8, and IL-1b in order to mimic the Danger-Associated Molecular Patterns present in the brain after ICH (ICH-DAMP), LPS, or vehicle for 14-18 hours. Cytokine production was quantified by cytometric bead array and activation markers by flow cytometry. ICH-DAMP was found to upregulate CCL2, IL-6 and TNF, recapitulating the inflammatory phenotype seen in the first days after ICH. However, when cells were stimulated in the presence of cholesterol, production of CCL2, IL-6, and TNF were limited. Dectin-1 has inhibitory properties in some sterile injury models. ICH-DAMP was found to limit expression of dectin-1, and cholesterol reversed this inhibition. Exposure to exogenous cholesterol also upregulated the cholesterol transporter ABCA1, allowing cells to efflux excess cholesterol. The drug Valspodar was therefore used to block cholesterol efflux and was found to further limit ICH-DAMP-mediated upregulation of CCL2. Conclusion: These results suggest that the cholesterol in the brain may limit macrophage activation in response to the stimuli present during intracerebral hemorrhage.


2019 ◽  
Vol 20 (1) ◽  
Author(s):  
Ricardo Ramirez ◽  
Allen Michael Herrera ◽  
Joshua Ramirez ◽  
Chunjiang Qian ◽  
David W. Melton ◽  
...  

Abstract Background Macrophages show versatile functions in innate immunity, infectious diseases, and progression of cancers and cardiovascular diseases. These versatile functions of macrophages are conducted by different macrophage phenotypes classified as classically activated macrophages and alternatively activated macrophages due to different stimuli in the complex in vivo cytokine environment. Dissecting the regulation of macrophage activations will have a significant impact on disease progression and therapeutic strategy. Mathematical modeling of macrophage activation can improve the understanding of this biological process through quantitative analysis and provide guidance to facilitate future experimental design. However, few results have been reported for a complete model of macrophage activation patterns. Results We globally searched and reviewed literature for macrophage activation from PubMed databases and screened the published experimental results. Temporal in vitro macrophage cytokine expression profiles from published results were selected to establish Boolean network models for macrophage activation patterns in response to three different stimuli. A combination of modeling methods including clustering, binarization, linear programming (LP), Boolean function determination, and semi-tensor product was applied to establish Boolean networks to quantify three macrophage activation patterns. The structure of the networks was confirmed based on protein-protein-interaction databases, pathway databases, and published experimental results. Computational predictions of the network evolution were compared against real experimental results to validate the effectiveness of the Boolean network models. Conclusion Three macrophage activation core evolution maps were established based on the Boolean networks using Matlab. Cytokine signatures of macrophage activation patterns were identified, providing a possible determination of macrophage activations using extracellular cytokine measurements.


2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Mariko Hara-Chikuma ◽  
Manami Tanaka ◽  
Alan S. Verkman ◽  
Masato Yasui

Abstract Aquaporin 3 (AQP3) is a transporter of water, glycerol and hydrogen peroxide (H2O2) that is expressed in various epithelial cells and in macrophages. Here, we developed an anti-AQP3 monoclonal antibody (mAb) that inhibited AQP3-facilitated H2O2 and glycerol transport, and prevented liver injury in experimental animal models. Using AQP3 knockout mice in a model of liver injury and fibrosis produced by CCl4, we obtained evidence for involvement of AQP3 expression in nuclear factor-κB (NF-κB) cell signaling, hepatic oxidative stress and inflammation in macrophages during liver injury. The activated macrophages caused stellate cell activation, leading to liver injury, by a mechanism involving AQP3-mediated H2O2 transport. Administration of an anti-AQP3 mAb, which targeted an extracellular epitope on AQP3, prevented liver injury by inhibition of AQP3-mediated H2O2 transport and macrophage activation. These findings implicate the involvement of macrophage AQP3 in liver injury, and provide evidence for mAb inhibition of AQP3-mediated H2O2 transport as therapy for macrophage-dependent liver injury.


Sign in / Sign up

Export Citation Format

Share Document