scholarly journals Network analysis reveals a distinct axis of macrophage activation in response to conflicting inflammatory cues

2019 ◽  
Author(s):  
Xiaji Liu ◽  
Jingyuan Zhang ◽  
Angela C. Zeigler ◽  
Anders R. Nelson ◽  
Merry L. Lindsey ◽  
...  
Keyword(s):  
Computational Model ◽  
Macrophage Activation ◽  
Expression Profiles ◽  
Interleukin 4 ◽  
Cytokine Signaling ◽  
Arginase 1 ◽  
M2 Polarization ◽  
Wide Range ◽  
Polarization Axis

AbstractMacrophages are subject to a wide range of cytokine and pathogen signals in vivo, which contribute to differential activation and modulation of inflammation. Understanding the response to multiple, often conflicting, cues that macrophages experience requires a network perspective. Here, we integrate data from literature curation and mRNA expression profiles to develop a large-scale computational model of the macrophage signaling network. In response to stimulation across all pairs of 9 cytokine inputs, the model predicted activation along the classic M1-M2 polarization axis but also a second axis of macrophage activation that distinguishes unstimulated macrophages from a mixed phenotype induced by conflicting cues. Along this second axis, combinations of conflicting stimuli, interleukin 4 (IL4) with lipopolysaccharide (LPS), interferon-γ (IFNγ), IFNβ, or tumor necrosis factor-α (TNFα), produced mutual inhibition of several signaling pathways, e.g. nuclear factor κB (NFκB) and signal transducer and activator of transcription 6 (STAT6), but also mutual activation of the phosphoinositide 3-kinases (PI3K) signaling module. In response to combined IFNγ and IL4, the model predicted genes whose expression was mutually inhibited, e.g. inducible nitric oxide synthase (iNOS) and arginase 1 (Arg1), or mutually enhanced, e.g. IL4 receptor-α (IL4Rα) and suppressor of cytokine signaling 1 (SOCS1), which was validated by independent experimental data. Knockdown simulations further predicted network mechanisms underlying functional crosstalk, such as mutual STAT3/STAT6-mediated enhancement of IL4Rα expression. In summary, the computational model predicts that network crosstalk mediates a broadened spectrum of macrophage activation in response to mixed pro- and anti-inflammatory cytokine cues, making it useful for modeling in vivo scenarios.Summary sentenceNetwork modeling of macrophage activation predicts responses to combinations of cytokines along both the M1-M2 polarization axis and a second axis associated with a mixed macrophage activation phenotype.

scholarly journals Simulation of P2X-mediated calcium signaling in microglia

2018 ◽  
Author(s):  
Ben Chun ◽  
Bradley D. Stewart ◽  
Darin Vaughan ◽  
Adam D. Bachstetter ◽  
Peter M. Kekenes-Huskey
Keyword(s):  
Computational Model ◽  
Purinergic Receptor ◽  
Receptor Activation ◽  
Quantitative Model ◽  
Published Data ◽  
Transcriptional Responses ◽  
Extracellular Adenosine ◽  
Wide Range ◽  
Intracellular Ca

AbstractMicroglia function is orchestrated through highly-coupled signaling pathways that depend on calcium (Ca2+). In response to extracellular adenosine triphosphate (ATP), transient increases in intracellular Ca2+ driven through the activation of purinergic receptors, P2X and P2Y, are sufficient to promote cytokine synthesis and potentially their release. While steps comprising the pathways bridging purinergic receptor activation with transcriptional responses have been probed in great detail, a quantitative model for how these steps collectively control cytokine production has not been established. Here we developed a minimal computational model that quantitatively links extracellular stimulation of two prominent ionotropic puriner-gic receptors, P2X4 and P2X7, with the graded production of a gene product, namely the tumor necrosis factor α (TNFα) cytokine. In addition to Ca2+ handling mechanisms common to eukaryotic cells, our model includes microglia-specific processes including ATP-dependent P2X4 and P2X7 activation, activation of NFAT transcription factors, and TNFα production. Parameters for this model were optimized to reproduce published data for these processes, where available. With this model, we determined the propensity for TNFα production in microglia, subject to a wide range of ATP exposure amplitudes, frequencies and durations that the cells could encounter in vivo. Furthermore, we have investigated the extent to which modulation of the signal transduction pathways influence TNFα production. Our key findings are that TNFα production via P2X4 is maximized at low ATP when subject to high frequency ATP stimulation, whereas P2X7 contributes most significantly at millimolar ATPranges. Given that Ca2+ homeostasis in microglia is profoundly important to its function, this computational model provides a quantitative framework to explore hypotheses pertaining to microglial physiology.

scholarly journals The Diverse Roles of the Global Transcriptional Regulator PhoP in the Lifecycle of Yersinia pestis

Pathogens ◽  
2020 ◽  
Vol 9 (12) ◽  
pp. 1039
Author(s):  
Hana S. Fukuto ◽  
Gloria I. Viboud ◽  
Viveka Vadyvaloo
Keyword(s):  
Yersinia Pestis ◽  
Current Knowledge ◽  
Response Regulator ◽  
Expression Profiles ◽  
Critical Role ◽  
Gene Expression Profiles ◽  
Acanthamoeba Castellanii ◽  
Wide Range

Yersinia pestis, the causative agent of plague, has a complex infectious cycle that alternates between mammalian hosts (rodents and humans) and insect vectors (fleas). Consequently, it must adapt to a wide range of host environments to achieve successful propagation. Y. pestis PhoP is a response regulator of the PhoP/PhoQ two-component signal transduction system that plays a critical role in the pathogen’s adaptation to hostile conditions. PhoP is activated in response to various host-associated stress signals detected by the sensor kinase PhoQ and mediates changes in global gene expression profiles that lead to cellular responses. Y. pestis PhoP is required for resistance to antimicrobial peptides, as well as growth under low Mg2+ and other stress conditions, and controls a number of metabolic pathways, including an alternate carbon catabolism. Loss of phoP function in Y. pestis causes severe defects in survival inside mammalian macrophages and neutrophils in vitro, and a mild attenuation in murine plague models in vivo, suggesting its role in pathogenesis. A Y. pestisphoP mutant also exhibits reduced ability to form biofilm and to block fleas in vivo, indicating that the gene is also important for establishing a transmissible infection in this vector. Additionally, phoP promotes the survival of Y. pestis inside the soil-dwelling amoeba Acanthamoeba castellanii, a potential reservoir while the pathogen is quiescent. In this review, we summarize our current knowledge on the mechanisms of PhoP-mediated gene regulation in Y. pestis and examine the significance of the roles played by the PhoP regulon at each stage of the Y. pestis life cycle.

scholarly journals Netrin-1-treated macrophages protect the kidney against ischemia-reperfusion injury and suppress inflammation by inducing M2 polarization

2013 ◽  
Vol 304 (7) ◽  
pp. F948-F957 ◽  
Author(s):  
Punithavathi Vilapakkam Ranganathan ◽  
Calpurnia Jayakumar ◽  
Ganesan Ramesh
Keyword(s):  
Reperfusion Injury ◽  
Macrophage Activation ◽  
Ischemia Reperfusion Injury ◽  
Ischemia Reperfusion ◽  
Macrophage Polarization ◽  
Kidney Injury ◽  
In Vitro Studies ◽  
Arginase 1 ◽  
M2 Polarization

Improper macrophage activation is pathogenically linked to various metabolic, inflammatory, and immune disorders. Therefore, regulatory proteins controlling macrophage activation have emerged as important new therapeutic targets. We recently demonstrated that netrin-1 regulates inflammation and infiltration of monocytes and ameliorates ischemia-reperfusion-induced kidney injury. However, it was not known whether netrin-1 regulates the phenotype of macrophages and the signaling mechanism through which it might do this. In this study, we report novel mechanisms underlying netrin-1's effects on macrophages using in vivo and in vitro studies. Overexpression of netrin-1 in spleen and kidney of transgenic mice increased expression of arginase-1, IL-4, and IL-13 and decreased expression of COX-2, indicating a phenotypic switch in macrophage polarization toward an M2-like phenotype. Moreover, flow cytometry analysis showed a significant increase in mannose receptor-positive macrophages in spleen compared with wild type. In vitro, netrin-1 induced the expression of M2 marker expression in bone marrow-derived macrophages, peritoneal macrophages, and RAW264.7 cells, and suppressed IFNγ-induced M1 polarization and production of inflammatory mediators. Adoptive transfer of netrin-1-treated macrophages suppressed inflammation and kidney injury against ischemia-reperfusion. Netrin-1 activated PPAR pathways and inhibition of PPAR activation abolished netrin-1-induced M2 polarization and suppression of cytokine production. Consistent with in vitro studies, administration of PPAR antagonist to mice abolished the netrin-1 protective effects against ischemia-reperfusion injury of the kidney. These findings illustrate that netrin-1 regulates macrophage polarization through PPAR pathways and confers anti-inflammatory actions in inflammed kidney tissue.

scholarly journals Unique Expression of Suppressor of Cytokine Signaling 3 Is Essential for Classical Macrophage Activation in Rodents In Vitro and In Vivo

2008 ◽  
Vol 180 (9) ◽  
pp. 6270-6278 ◽  
Author(s):  
Yu Liu ◽  
Keith N. Stewart ◽  
Eileen Bishop ◽  
Carylyn J. Marek ◽  
David C. Kluth ◽  
...  
Keyword(s):  
Macrophage Activation ◽  
Cytokine Signaling ◽  
Suppressor Of Cytokine Signaling

scholarly journals Lactoferrin-containing immunocomplex mediates antitumor effects by resetting tumor-associated macrophages to M1 phenotype

2020 ◽  
Vol 8 (1) ◽  
pp. e000339 ◽  
Author(s):  
Hongliang Dong ◽  
Yueyao Yang ◽  
Chenhui Gao ◽  
Hehe Sun ◽  
Hongmin Wang ◽  
...  
Keyword(s):  
Protective Efficacy ◽  
Suppressor Cells ◽  
Interleukin 10 ◽  
Interleukin 4 ◽  
Tumor Associated Macrophages ◽  
Antitumor Effects ◽  
Tumoricidal Activity ◽  
Arginase 1

BackgroundTumor-associated macrophages (TAMs) resemble M2-polarized cells with potent immunosuppressive activity and play a pivotal role in tumor growth and progression. Converting TAMs to proinflammatory M1-like phenotype is thus an attractive strategy for antitumor immunotherapy.MethodsA mouse IgG1(kappa) monoclonal Ab, M-860, specific to human lactoferrin (LTF) was generated by using the traditional hybridoma cell fusion technology. TAMs were generated by culturing human and mouse CD14+monocytes in tumor-conditioned media containing a cytokine cocktail containing recombinant interleukin-4 (IL-4), interleukin-10 (IL-10) and macrophage colony stimulating factor (M-CSF). TAMs after treatment with immunocomplex (IC) between human LTF and M860 (LTF-IC) were phenotypically and functionally characterized by flow cytometry (FACS), ELISA, Q-PCR and killing assays. The antitumor effects of LTF-IC were further analyzed using in vivo experiments employing tumor-bearing human FcγRIIa-transgenic mouse models.ResultsThrough coligation of membrane-bound CD14 and FcγRIIa, LTF-IC rendered TAMs not only M2 to M1 conversion, evidenced by increased tumor necrosis factor α production, down-regulated M2-specific markers (CD206, arginase-1 and vascular endothelial growth factor) and upregulated M1-specific markers (CD86 and HLA-DR) expression, but also potent tumoricidal activity in vitro. LTF-IC administration conferred antitumor protective efficacy and prolonged animal survival in FcγRIIa-transgenic mice, accompanied by accumulation of M1-like macrophages as well as significantly reduced infiltration of immunosuppressive myeloid-derived suppressor cells and regulatory T cells in solid tumor tissues.ConclusionsLTF-IC is a promising cancer therapeutic agent capable of converting TAMs into tumoricidal M1-like cells.

scholarly journals IL-4 Alleviates Ischaemia-Reperfusion Injury by Inducing Kupffer Cells M2 Polarization via STAT6-JMJD3 Pathway after Rat Liver Transplantation

2020 ◽  
Vol 2020 ◽  
pp. 1-12
Author(s):  
Minghua Deng ◽  
Jingyuan Wang ◽  
Hao Wu ◽  
Menghao Wang ◽  
Ding Cao ◽  
...  
Keyword(s):  
Liver Transplantation ◽  
Reperfusion Injury ◽  
Kupffer Cells ◽  
Interleukin 4 ◽  
Ischaemia Reperfusion Injury ◽  
Ischaemia Reperfusion ◽  
M2 Polarization ◽  
Hepatocellular Apoptosis

Background. Liver ischaemia-reperfusion injury (IRI) remains a problem in liver transplantation. Interleukin-4 (IL-4) has been found to reduce liver IRI, but the exact mechanism remains unclear. Methods. Donor livers were infused with recombinant IL-4 or normal saline during cold storage, and the hepatocellular apoptosis and the inflammatory response were detected. The effect of IL-4 treatment on Kupffer cells (KCs) polarization and expression of the STAT6-JMJD3 pathway was evaluated in vivo and in vitro. KCs in donor livers were depleted by clodronate liposome treatment or JMJD3 was inhibited by GSK-J4 before liver transplantation to determine whether the protective effect of IL-4 treatment was dependent on KCs. Results. IL-4 treatment decreased sALT and sAST levels and alleviated hepatocellular apoptosis and inflammation at 6 h after liver transplantation. IL-4 treatment induced KCs alternatively activated (M2) polarization in vitro and in vivo, and the expression of STAT6 and JMJD3 was increased. JMJD3 knockdown abolished KCs M2 polarization and reduced the antiapoptotic and anti-inflammatory effects induced by IL-4 treatment in vitro. In addition, the protection of IL-4 treatment against IRI induced by liver transplantation was significantly reduced after the depletion of KCs or the inhibition of JMJD3 in donor livers. Conclusions. IL-4 treatment-induced KCs M2 polarization was dependent on the STAT6-JMJD3 pathway and protected liver grafts from IRI after liver transplantation.

scholarly journals Venular endothelium-derived NO can affect paired arteriole: a computational model

2006 ◽  
Vol 290 (2) ◽  
pp. H716-H723 ◽  
Author(s):  
Mahendra Kavdia ◽  
Aleksander S. Popel
Keyword(s):  
Smooth Muscle ◽  
Computational Model ◽  
Reaction Rate ◽  
Soluble Guanylate Cyclase ◽  
Experimental Studies ◽  
Vascular Wall ◽  
No Production ◽  
Wide Range ◽  
Venular Endothelium

Venular endothelial cells can release nitric oxide (NO) in response to intraluminal flow both in isolated venules and in vivo. Experimental studies suggest that venular endothelium-released NO causes dilation of the adjacent paired arteriole. In the vascular wall, NO stimulates its target hemoprotein, soluble guanylate cyclase (sGC), which relaxes smooth muscle cells. In this study, a computational model of NO transport for an arteriole and venule pair was developed to determine the importance of the venular endothelium-released NO and its transport to the adjacent arteriole in the tissue. The model predicts that the tissue NO levels are affected within a wide range of parameters, including NO-red blood cell reaction rate and NO production rate in the arteriole and venule. The results predict that changes in the venular NO production affected not only venular endothelial and smooth muscle NO concentration but also endothelial and smooth muscle NO concentration in the adjacent arteriole. This suggests that the anatomy of microvascular tissue can permit the transport of NO from arteriolar to venular side, and vice versa, and may provide a mechanism for dilation of proximal arterioles by venules. These results will have significant implications for our understanding of tissue NO levels in both physiological and pathophysiological conditions.

scholarly journals Silicone Implants Immobilized with Interleukin-4 Promote the M2 Polarization of Macrophages and Inhibit the Formation of Fibrous Capsules

Polymers ◽  
2021 ◽  
Vol 13 (16) ◽  
pp. 2630
Author(s):  
Hyun-Seok Kim ◽  
Seongsoo Kim ◽  
Byung-Ho Shin ◽  
Chan-Yeong Heo ◽  
Omar Faruq ◽  
...  
Keyword(s):  
Tissue Regeneration ◽  
Capsular Contracture ◽  
Silicone Implant ◽  
Interleukin 4 ◽  
Silicone Implants ◽  
M2 Macrophage ◽  
Macrophage Phenotype ◽  
Arginase 1

Breast augmentations with silicone implants can have adverse effects on tissues that, in turn, lead to capsular contracture (CC). One of the potential ways of overcoming CC is to control the implant/host interaction using immunomodulatory agents. Recently, a high ratio of anti-inflammatory (M2) macrophages to pro-inflammatory (M1) macrophages has been reported to be an effective tissue regeneration approach at the implant site. In this study, a biofunctionalized implant was coated with interleukin (IL)-4 to inhibit an adverse immune reaction and promoted tissue regeneration by promoting polarization of macrophages into the M2 pro-healing phenotype in the long term. Surface wettability, nitrogen content, and atomic force microscopy data clearly showed the successful immobilization of IL-4 on the silicone implant. Furthermore, in vitro results revealed that IL-4-coated implants were able to decrease the secretion of inflammatory cytokines (IL-6 and tumor necrosis factor-α) and induced the production of IL-10 and the upregulation of arginase-1 (mannose receptor expressed by M2 macrophage). The efficacy of this immunomodulatory implant was further demonstrated in an in vivo rat model. The animal study showed that the presence of IL-4 diminished the capsule thickness, the amount of collagen, tissue inflammation, and the infiltration of fibroblasts and myofibroblasts. These results suggest that macrophage phenotype modulation can effectively reduce inflammation and fibrous CC on a silicone implant conjugated with IL-4.

Abstract 18687: PARP9 and PARP14 are Novel Regulators of Macrophage Activation

Circulation ◽  
2014 ◽  
Vol 130 (suppl_2) ◽  
Author(s):  
Hiroshi Iwata ◽  
Hideo Yoshida ◽  
Piero Ricchiuto ◽  
Takuya Hara ◽  
Iwao Yamada ◽  
...  
Keyword(s):  
Macrophage Activation ◽  
High Resolution Mass Spectrometry ◽  
Macrophage Phenotype ◽  
Adp Ribosylation ◽  
Macrophage Activity ◽  
Arginase 1 ◽  
Anti Inflammatory ◽  
Unstable Plaques ◽  
Underlying Mechanisms

Background: Pro-inflammatory “M1” macrophages may promote atherogenesis, while “M2” macrophages may favor an anti-inflammatory milieu. Our global proteomics of M1 and M2 cells identified ADP-ribosylation enzymes PARP9 and PARP14 as novel regulators of macrophage activation. The present study has examined the underlying mechanisms and explored in vivo evidence for their role in vascular disease. Methods and Results: IFN gamma (M1) stimulation induced and IL-4 (M2) decreased PARP9 and PARP14 in mouse and human macrophages. siRNA silencing of PARP14 enhanced expression of M1 genes (e.g. TNFα, iNOS) and activation (phosphorylation) of pro-inflammatory STAT1 while suppressing M2 markers (e.g., Arginase 1) and anti-inflammatory STAT6. Conversely, PARP9 silencing suppressed M1 polarization and STAT1 activation. These results suggest that PARP14 inhibits and PARP9 promotes a pro-inflammatory macrophage phenotype. Co-immunoprecipitation indicated that PARP14 and PARP9 physically interact. ADP-ribosylation assays revealed that PARP9 impairs PARP14-induced ribosylation (Figure A). Targeted proteomics via high-resolution mass spectrometry demonstrated that PARP14 ADP-ribosylates at least two sites in STAT1α, which PARP9 suppressed. Mechanically injured arteries of Parp14-/- mice had accelerated lesion formation and macrophage accumulation. Peritoneal and plaque macrophages of PARP14-/- mice showed increased STAT1 phosphorylation, decreased STAT6 phosphorylation, enhanced M1 gene expression, and reduced M2 responses (Figure B, laser capture microdissection). More macrophages[[Unable to Display Character: &#61472;]]were immunoreactive for PARP9 in human “unstable” plaques than in “stable” plaques (64.6±16.2% vs. 30.8±12.3%, p<0.01, n=5). Conclusions: PARP14 and PARP9 reciprocally regulate the mechanisms of macrophage activation, offering the potential for new therapies for cardiovascular diseases and other conditions, in which macrophage activity impacts outcomes.

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