scholarly journals Alternative activation of macrophages by prostacyclin synthase ameliorates alcohol induced liver injury

2021 ◽  
Author(s):  
Xue-yin Pan ◽  
Ling Wang ◽  
Hong-mei You ◽  
Miao Cheng ◽  
Yang Yang ◽  
...  
Keyword(s):  
Liver Disease ◽  
Viral Vector ◽  
Macrophage Polarization ◽  
Janus Kinase ◽  
Luciferase Assay ◽  
Alternative Activation ◽  
Rna Seq ◽  
String Database ◽  
M2 Polarization ◽  
M1 Phenotype

AbstractAlcoholic liver disease (ALD) is a major cause of chronic liver disease worldwide. Macrophages exhibit different functional states and are classified as classically activated (M1) and alternatively activated (M2) macrophages. However, the mechanisms that govern M1/M2 polarization in chronic ALD remain to be elucidated. Prostacyclin (PGI2) synthase (PTGIS) is an enzyme of the prostaglandin pathway which catalyzes the conversion of Prostaglandin H2 (PGH2) to PGI2. PTGIS has anti-inflammatory properties. However, the function of PTGIS in ALD has not yet been determined. In this study, we demonstrated that PTGIS was downregulated in ALD and forced PTGIS expression in vivo using recombinant adeno-associated viral vector-packed PTGIS overexpression plasmid, which alleviated the inflammatory response and suppressed the macrophage M1 phenotype in mice. Loss- and gain-of function-experiments demonstrated that forced PTGIS expression inhibited the macrophage switch to the M1 phenotype and promoted M2 polarization. Furthermore, we identified the genes regulated by PTGIS through RNA-sequencing (RNA-seq) analysis. Gene ontology and KEGG pathway analyses showed that PTGIS regulates many genes involved in the immune response and is enriched in the Janus kinase/signal transducers and activators of transcription (JAK/STAT) signal transduction pathway, which plays an important role in regulating macrophage polarization. The proteins interacting with JAKs were predicted using the STRING database. The overlap between the RNA-seq and the STRING database was interleukin-6; this indicated that it was involved in macrophage polarization regulated by JAK/STAT signaling. We further explored the microRNAs that could regulate the expression of PTGIS through TargetScan. The results of luciferase assay illustrated that the expression of PTGIS was regulated by miR-140-3p.1. These results imply that PTGIS plays a pivotal role in ALD, partly by influencing macrophage polarization.

scholarly journals Xuebijing Injection Promotes M2 Polarization of Macrophages and Improves Survival Rate in Septic Mice

2015 ◽  
Vol 2015 ◽  
pp. 1-9 ◽  
Author(s):  
Yan-Cun Liu ◽  
Feng-Hua Yao ◽  
Yan-Fen Chai ◽  
Ning Dong ◽  
Zhi-Yong Sheng ◽  
...  
Keyword(s):  
Survival Rate ◽  
Macrophage Polarization ◽  
Janus Kinase ◽  
Chinese Herbs ◽  
Control Group ◽  
Septic Complications ◽  
M2 Polarization ◽  
Janus Kinase 1 ◽  
Cytokine Levels ◽  
Specific Proteins

Xuebijing (XBJ) injection, a concoction of several Chinese herbs, has been widely used as an immunomodulator for the treatment of severe sepsis in China. However, the precise mechanisms responsible for its efficacy have not been fully elucidated. In our study, we determined the flow cytometry markers (F4/80, CD11c, and CD206), the levels of secreted cytokines (TNF-α, IL-6, and IL-10), and the expression of specific proteins of M2 (Ym1, Fizz1, and Arg1) to assess macrophage polarization. Treatment with XBJ lowered M1 associated cytokine levels and increased the level of M2 associated cytokine level. The percentage of M2 phenotype cells of XBJ group was much higher than that of the control group. Expressions of phosphorylated Janus kinase 1 (JAK1) and signal transducer and activator of transcription 6 (STAT6) were markedly enhanced after the administration of XBJ; on the other hand, the M2 associated cytokines and proteins were decreased following treatment with JAK1 or STAT6 inhibitor. In addition, the treatment of XBJ significantly improved the survival rate of septic mice. These studies demonstrate that XBJ can markedly promote M2 polarization and improve the survival rate of septic mice, thereby contributing to therapeutic effect in the treatment of septic complications.

scholarly journals Arachidonic Acid Metabolism Controls Macrophage Alternative Activation Through Regulating Oxidative Phosphorylation in PPARγ Dependent Manner

2021 ◽  
Vol 12 ◽  
Author(s):  
Miao Xu ◽  
Xiaohong Wang ◽  
Yongning Li ◽  
Xue Geng ◽  
Xudong Jia ◽  
...  
Keyword(s):  
Arachidonic Acid ◽  
Oxidative Phosphorylation ◽  
Acid Metabolism ◽  
Macrophage Polarization ◽  
Arachidonic Acid Metabolism ◽  
Metabolic Reprogramming ◽  
Alternative Activation ◽  
Dependent Manner ◽  
M2 Polarization

Macrophage polarization is mainly steered by metabolic reprogramming in the tissue microenvironment, thus leading to distinct outcomes of various diseases. However, the role of lipid metabolism in the regulation of macrophage alternative activation is incompletely understood. Using human THP-1 and mouse bone marrow derived macrophage polarization models, we revealed a pivotal role for arachidonic acid metabolism in determining the phenotype of M2 macrophages. We demonstrated that macrophage M2 polarization was inhibited by arachidonic acid, but inversely facilitated by its derived metabolite prostaglandin E2 (PGE2). Furthermore, PPARγ bridges these two seemingly unrelated processes via modulating oxidative phosphorylation (OXPHOS). Through inhibiting PPARγ, PGE2 enhanced OXPHOS, resulting in the alternative activation of macrophages, which was counterweighted by the activation of PPARγ. This connection between PGE2 biosynthesis and macrophage M2 polarization also existed in human and mouse esophageal squamous cell carcinoma. Our results highlight the critical role of arachidonic acid and metabolic PGE2 as immune regulators in modulating tissue homeostasis and pathological process.

scholarly journals LncGBP9/miR-34a axis drives macrophages toward a phenotype conducive for spinal cord injury repair via STAT1/STAT6 and SOCS3

2020 ◽  
Author(s):  
Jiahui Zhou ◽  
Zhiyue Li ◽  
Tianding Wu ◽  
Qun Zhao ◽  
Qiancheng Zhao ◽  
...  
Keyword(s):  
Spinal Cord ◽  
Spinal Cord Injury ◽  
Macrophage Polarization ◽  
Cytokine Signaling ◽  
Secondary Injury ◽  
Protein Levels ◽  
M2 Polarization ◽  
Cord Injury ◽  
Socs3 Expression ◽  
M1 Phenotype

Abstract Background: Acute spinal cord injury (SCI) could cause mainly two types of pathological sequelae, the primary mechanical injury, and the secondary injury. The macrophage in SCI are skewed toward the M1 phenotype that might cause the failure to post-SCI repair. Methods: SCI model was established in Balb/c mice, and the changes in macrophage phenotypes after SCI were monitored. Bioinformatic analyses were performed to select factors that might regulate macrophage polarization after SCI. Mouse bone marrow-derived macrophages ( BMDMs ) were isolated, identified, and induced for M1 or M2 polarization; the effects of lncRNA guanylate binding protein-9 (lnc GBP9 ) and suppressor of cytokine signaling 3 (SOCS 3) on macrophages polarization were examined in vitro and in vivo . The predicted miR-34a binding to lncGBP9 and SOCS3 was validated; the dynamic effects of lncGBP9 and miR-34a on SOCS3, signal transducer and activator of transcription 1 (STAT 1) /STAT6 signaling, and macrophage polarization were examined. Finally, we investigated whether STAT6 could bind the miR-34a promoter to activate its transcription. Results: In SCI Balb/c mice, macrophage skewing toward M1 phenotypes was observed after SCI. In M1 macrophages, lncGBP9 silencing significantly decreased p-STAT1 and SOCS3 expression and protein levels, as well as the production of Interleukin (IL)-6 and IL-12; in M2 macrophages, lncGBP9 overexpression increased SOCS3 mRNA expression and protein levels while suppressed p-STAT6 levels and the production of IL-10 and transforming growth factor-beta 1 (TGF-β1 ) , indicating that lncGBP9 overexpression promotes the M1 polarization of macrophages. In lncGBP9-silenced SCI mice, the M2 polarization was promoted on day 28 after the operation, further indicating that lncGBP9 silencing revised the predominance of M1 phenotype at the late stage of secondary injury after SCI, therefore improving the repair after SCI. IncGBP9 competed with SOCS3 for miR-34a binding to counteract miR-34a-mediated suppression on SOCS3 and then modulated STAT1/STAT6 signaling and the polarization of macrophages. STAT6 bound the promoter of miR-34a to activate its transcription. Conclusions: In macrophages, lncGBP9 sponges miR-34a to rescue SOCS3 expression, therefore modulating macrophage polarization through STAT1/STAT6 signaling. STAT6 bound the promoter of miR-34a to activate its transcription, thus forming two different regulatory loops to modulate the phenotype of macrophages after SCI.

scholarly journals Luteolin transforms the BMDM polarity to regulate the expression of inflammatory factors

2020 ◽  
Author(s):  
Shuxia Wang ◽  
Shuhang Xu ◽  
Meng Cao ◽  
Jing Zhou ◽  
Xiaodong Mao ◽  
...  
Keyword(s):  
Bone Marrow Cells ◽  
Macrophage Polarization ◽  
Membrane Surface ◽  
Inflammatory Factors ◽  
Mouse Bone Marrow ◽  
M2 Polarization ◽  
M1 Phenotype ◽  
Ifn Γ ◽  
Anti Inflammatory ◽  
M1 Type

ABSTRACTMacrophage are indispensable regulator cells in inflammatory response. Macrophage polarization and its secreted inflammatory factors have affinity with the outcomes of inflammation. Luteolin, a flavonoid abundant in plants has anti-inflammatory activity, but whether luteolin can manipulate M1/M2 polarization of BMDM to suppress inflammation is still veiled. The purpose of this study was to observe the effects of luterolin on the polarity of BMDM derived from C57BL/6 mice and the expression of inflammatory factors, to explore the mechanism of luteolin regulating the BMDM polarity. M1-polarized BMDM were induced by LPS+IFN-γ, M2-polarization were stimulated with IL-4. BMDM morphology was observed by laser confocal microscopy; levels of BMDM differentiation and CD11c or CD206 on membrane surface were assessed by FCM; mRNA and protein of M1/M2-type inflammatory factors were performed by qPCR and ELISA, respectively; the expression of p-STAT1 and p-STAT6 protein pathways was detected by Western-blotting. The isolated mouse bone marrow cells were successfully differentiated into BMDM, LPS+IFN-γ induced BMDM M1-phenotype polarization, and IL-4 induced its M2-phenotype polarization. After M1-polarized BMDM treated with luteolin, M1-type pro-inflammatory factors including IL-6, TNF-α□iNOS, CD86 were down-regulated while M2-type anti-inflammatory factors including IL-10, Arg1, CD206 were up-regulated; the expression of M1-type surface marker CD11c decreased, nevertheless, M2-type marker CD206 increased; levels of inflammatory signaling protein p-STAT1 and p-STAT6 were attenuated and enhanced respectively. Our study suggests luteolin may transform BMDM polarity through p-STAT1/6 to regulate the expression of inflammatory mediators, thereby inhibiting inflammation. Naturally occurring luteolin hold promise as an anti-inflammatory and immunomodulatory agent.

scholarly journals Kdm2a deficiency in macrophages enhances thermogenesis to protect mice against HFD-induced obesity by enhancing H3K36me2 at the Pparg locus

2021 ◽  
Author(s):  
Longmin Chen ◽  
Jing Zhang ◽  
Yuan Zou ◽  
Faxi Wang ◽  
Jingyi Li ◽  
...  
Keyword(s):  
Insulin Resistance ◽  
High Fat Diet ◽  
Macrophage Polarization ◽  
Fatty Acid Uptake ◽  
Chromatin Accessibility ◽  
Acid Uptake ◽  
High Fat ◽  
M2 Polarization ◽  
Adipose Tissue Macrophages ◽  
Cold Challenge

AbstractKdm2a catalyzes H3K36me2 demethylation to play an intriguing epigenetic regulatory role in cell proliferation, differentiation, and apoptosis. Herein we found that myeloid-specific knockout of Kdm2a (LysM-Cre-Kdm2af/f, Kdm2a−/−) promoted macrophage M2 program by reprograming metabolic homeostasis through enhancing fatty acid uptake and lipolysis. Kdm2a−/− increased H3K36me2 levels at the Pparg locus along with augmented chromatin accessibility and Stat6 recruitment, which rendered macrophages with preferential M2 polarization. Therefore, the Kdm2a−/− mice were highly protected from high-fat diet (HFD)-induced obesity, insulin resistance, and hepatic steatosis, and featured by the reduced accumulation of adipose tissue macrophages and repressed chronic inflammation following HFD challenge. Particularly, Kdm2a−/− macrophages provided a microenvironment in favor of thermogenesis. Upon HFD or cold challenge, the Kdm2a−/− mice manifested higher capacity for inducing adipose browning and beiging to promote energy expenditure. Collectively, our findings demonstrate the importance of Kdm2a-mediated H3K36 demethylation in orchestrating macrophage polarization, providing novel insight that targeting Kdm2a in macrophages could be a viable therapeutic approach against obesity and insulin resistance.

scholarly journals TNF and Increased Intracellular Iron Alter Macrophage Polarization to a Detrimental M1 Phenotype in the Injured Spinal Cord

Neuron ◽  
2014 ◽  
Vol 83 (5) ◽  
pp. 1098-1116 ◽  
Author(s):  
Antje Kroner ◽  
Andrew D. Greenhalgh ◽  
Juan G. Zarruk ◽  
Rosmarini Passos dos Santos ◽  
Matthias Gaestel ◽  
...  
Keyword(s):  
Spinal Cord ◽  
Macrophage Polarization ◽  
Injured Spinal Cord ◽  
Intracellular Iron ◽  
M1 Phenotype

Abstract T P80: Inhibition of Ezh2 Leads to Decreased M1 and Enhanced M2 Microglia Phenotypes

Stroke ◽  
2015 ◽  
Vol 46 (suppl_1) ◽  
Author(s):  
Edward Koellhoffer ◽  
Jeremy Grenier ◽  
Rodney Ritzel ◽  
Louise McCullough
Keyword(s):  
Ischemic Stroke ◽  
Pcr Analysis ◽  
M2 Polarization ◽  
M2 Microglia ◽  
M1 Polarization ◽  
Glial Cultures ◽  
M2 Response ◽  
M1 Phenotype ◽  
Cayman Chemical ◽  
M2 Phenotype

Background: Ischemic stroke results in the activation of microglia, which may polarize toward a pro-inflammatory (M1) phenotype or an anti-inflammatory, neuroprotective (M2) phenotype. Thus, simultaneously suppressing the M1 response and promoting the M2 response could be beneficial in the treatment of stroke. Recently, the epigenetic modulator Jmjd3 has been shown to be essential for M2 polarization. However, Jmjd3 is antagonized by Ezh2 which is associated with M1 polarization. Thus, we hypothesized that inhibition of Ezh2 tilts the balance between Jmjd3 and Ezh2, thereby enhancing polarization toward an M2 phenotype and improved outcome in ischemic stroke. Methods: Mixed glial cultures were isolated from P0.5-P2 C57BL/6J mice and cultured for 14 days before microglial isolation. Microglia were rested for 24 hours before treatment every other day with 6uM GSK343 (Cayman Chemical) or DMSO vehicle control. After 7 days, microglia were stimulated with LPS or IL-4 and RNA was isolated at 4hr and 24hr post-stimulation for qRT-PCR analysis. Results: LPS-induced IL6 and IL1B expression was significantly abrogated by 71% and 53%, respectively (p<0.05), at 24hr when Ezh2 was inhibited. Additionally, Ezh2 inhibition both increased baseline expression of M2-associated genes ARG1, CD206, and IRF4 by 196%, 257%, and 395%, respectively (p<0.05), and rescued their expression in the presence of LPS at 24hr (p<0.05) in which they were otherwise significantly down-regulated. Conclusion: Pharmacological inhibition of Ezh2 limits microglial M1 polarization and enhances M2 polarization.

scholarly journals Interstitial flow promotes macrophage polarization toward an M2 phenotype

2018 ◽  
Vol 29 (16) ◽  
pp. 1927-1940 ◽  
Author(s):  
Ran Li ◽  
Jean Carlos Serrano ◽  
Hao Xing ◽  
Tara A. Lee ◽  
Hesham Azizgolshani ◽  
...  
Keyword(s):  
Fluid Flow ◽  
Tumor Microenvironment ◽  
Tumor Progression ◽  
Cancer Cell ◽  
Interstitial Fluid ◽  
Macrophage Polarization ◽  
Interstitial Flow ◽  
Interstitial Fluid Flow ◽  
M2 Polarization ◽  
Tumor Tissues

Tumor tissues are characterized by an elevated interstitial fluid flow from the tumor to the surrounding stroma. Macrophages in the tumor microenvironment are key contributors to tumor progression. While it is well established that chemical stimuli within the tumor tissues can alter macrophage behaviors, the effects of mechanical stimuli, especially the flow of interstitial fluid in the tumor microenvironment, on macrophage phenotypes have not been explored. Here, we used three-dimensional biomimetic models to reveal that macrophages can sense and respond to pathophysiological levels of interstitial fluid flow reported in tumors (∼3 µm/s). Specifically, interstitial flow (IF) polarizes macrophages toward an M2-like phenotype via integrin/Src-mediated mechanotransduction pathways involving STAT3/6. Consistent with this flow-induced M2 polarization, macrophages treated with IF migrate faster and have an enhanced ability to promote cancer cell migration. Moreover, IF directs macrophages to migrate against the flow. Since IF emanates from the tumor to the surrounding stromal tissues, our results suggest that IF could not only induce M2 polarization of macrophages but also recruit these M2 macrophages toward the tumor masses, contributing to cancer cell invasion and tumor progression. Collectively, our study reveals that IF could be a critical regulator of tumor immune environment.

scholarly journals Luteolin Inhibits Respiratory Syncytial Virus Replication by Regulating the MiR-155/SOCS1/STAT1 Signaling Pathway

2020 ◽  
Author(s):  
Saisai Wang ◽  
Yiting Ling ◽  
Yuanyuan Yao ◽  
Gang Zheng ◽  
Wenbin Chen
Keyword(s):  
Respiratory Syncytial Virus ◽  
Signaling Pathway ◽  
Western Blotting ◽  
Virus Replication ◽  
Janus Kinase ◽  
Luciferase Assay ◽  
Luciferase Reporter ◽  
Cytokine Signaling ◽  
Stat1 Signaling ◽  
Syncytial Virus

Abstract Background: Respiratory syncytial virus (RSV) is a major cause of acute lower respiratory tract infection in infants, children, immunocompromised adults, and elderly individuals. Currently, there are few therapeutic options available to prevent RSV infection. The present study aimed to investigate the effects of luteolin on RSV replication and the related mechanisms. Material and methods: We pretreated cells and mice with luteolin before infection with RSV, the virus titer, expressions of RSV-F, interferon (IFN)-stimulated genes (ISGs), and production of IFN-α and IFN-β were determined by plaque assay, RT-qPCR, and ELISA, respectively. The activation of Janus kinase (JAK)-signal transducer and activator of transcription 1 (STAT1) signaling pathway was detected by Western blotting and luciferase assay. Proteins which negatively regulates STAT1 was determined by Western blotting. Then cells were transfected with suppressor of cytokine signaling 1 (SOCS1) plasmid and virus replication and ISGs expression was determined. Luciferase reporter assay and Western blotting was performed to detect the relationship between SOCS1 and miR-155. Results: Luteolin inhibited RSV replication, as shown by the decreased viral titer and RSV-F mRNA expression both in vitro and in vivo. The antiviral activity of luteolin was attributed to the enhanced phosphorylation of STAT1, resulting in the increased production of ISGs. Further study showed that SOCS1 was downregulated by luteolin and SOCS1 is a direct target of microRNA-155 (miR-155). Inhibition of miR-155 rescued luteolin-mediated SOCS1 downregulation, whereas upregulation of miR-155 enhanced the inhibitory effect of luteolin. Conclusion: Luteolin inhibits RSV replication by regulating the miR-155/SOCS1/STAT1 signaling pathway.

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