MiR-19a-3p Suppresses M1 Macrophage Polarization by Inhibiting STAT1/IRF1 Pathway

Macrophages, an important type of immune cells, are generally polarized to classically activated macrophage (M1) or alternatively activated macrophage (M2) to respond to environmental stimuli. Signal transducer and activator of transcription 1 (STAT1), a very important transcription factor, can promote M1 macrophage polarization. However, the mechanisms of regulating STAT1 in macrophage polarization remain unclear. In the present study, STAT1 was markedly elevated, however, miR-19a-3p was down-regulated in interferon (IFN)-γ and lipopolysaccharide (LPS) treated RAW264.7 cells, and dual-luciferase reporter assay identified that miR-19a-3p directly targeted STAT1 by binding to its 3′UTR. Up-regulated miR-19a-3p inhibited M1 polarization by targeting STAT1/interferon regulatory factor 1 (IRF1) and vice versa in vitro. Consistently, overexpression of miR-19a-3p in LPS treated mice by systemically administering agomiR-19a-3p effectively reduced the inflammation in mouse lung tissues, and inhibited M1 macrophage polarization via suppressing STAT1/IRF1 pathway. In summary, our study confirmed that miR-19a-3p, as a direct regulator of STAT1, inhibited M1 macrophages polarization. The miR-19a-3p/STAT1/IRF1 pathway can potentially be used to design novel immunotherapy for modulating macrophage polarization.

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Kaempferol Alleviates Corneal Transplantation Rejection by Inhibiting NLRP3 Inflammasome Activation and Macrophage M1 Polarization via Promoting Autophagy

10.21203/rs.3.rs-368448/v1 ◽

2021 ◽

Author(s):

Huiwen Tian ◽

Shumei Lin ◽

Jing Wu ◽

Ming Ma ◽

Jian Yu ◽

...

Keyword(s):

Nlrp3 Inflammasome ◽

Macrophage Polarization ◽

Corneal Transplantation ◽

Inflammasome Activation ◽

M1 Polarization ◽

Nlrp3 Inflammasome Activation ◽

M1 Macrophage ◽

Transplantation Rejection

Abstract Corneal transplantation rejection remains a major threat to the success rate in high-risk patients. Given the many side effects presented by traditional immunosuppressants, there is an urgency to clarify the mechanism of corneal transplantation rejection and to identify new therapeutic targets. Kaempferol is a natural flavonoid that has been proven in various studies to possess anti-inflammatory, antioxidant, anticancer, and neuroprotective properties. However, the relationship between kaempferol and corneal transplantation remains largely unexplored. To address this, both in vivo and in vitro, we established a model of corneal allograft transplantation in Wistar rats and an LPS-induced inflammatory model in THP-1 derived human macrophages. In the transplantation experiments, we observed an enhancement in the NLRP3 / IL-1 β axis and in M1 macrophage polarization post-operation. In groups to which kaempferol intraperitoneal injections were administered, this response was effectively reduced. However, the effect of kaempferol was reversed after the application of autophagy inhibitors. Similarly, in the inflammatory model, we found that different concentrations of kaempferol can reduce the LPS-induced M1 polarization and NLRP3 inflammasome activation. Moreover, we confirmed that kaempferol induced autophagy and that autophagy inhibitors reversed the effect in macrophages. In conclusion, we found that kaempferol can inhibit the activation of the NLRP3 inflammasomes by inducing autophagy, thus inhibiting macrophage polarization, and ultimately alleviating corneal transplantation rejection. Thus, our study suggests that kaempferol could be used as a potential therapeutic agent in the treatment of allograft rejection.

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A Benzenediamine Analog FC-99 Drives M2 Macrophage Polarization and Alleviates Lipopolysaccharide- (LPS-) Induced Liver Injury

Mediators of Inflammation ◽

10.1155/2019/7823069 ◽

2019 ◽

Vol 2019 ◽

pp. 1-9 ◽

Cited By ~ 2

Author(s):

Wei Gong ◽

Haiyan Zhu ◽

Li Lu ◽

Yayi Hou ◽

Huan Dou

Keyword(s):

Liver Injury ◽

Macrophage Polarization ◽

M2 Macrophage ◽

M1 Macrophage ◽

M2 Macrophage Polarization ◽

Underlying Mechanisms ◽

Sirna Knockdown ◽

Lower Expression ◽

Alternatively Activated

Macrophages have variable functional phenotypes, high diversity, and plasticity and are involved in the pathogenesis of sepsis-induced liver injury. Alteration of macrophage polarization through activated (M1) macrophage to alternatively activated (M2) macrophage has emerged as a potential therapeutic strategy. This study was designed to explore the effect of a benzenediamine analog FC-99 on macrophage polarization in vitro and lipopolysaccharide- (LPS-) induced liver injury followed by the underlying mechanisms. For in vitro experiments, FC-99 inhibited M1-related macrophage factors and promoted M2-related markers induced by IL-4 in the mouse macrophage cell line RAW264.7. Moreover, FC-99-induced macrophages polarized to M2 phenotype which could be repressed by a PPAR-γ inhibitor but not STAT6 siRNA knockdown, indicating FC-99-induced M2 macrophage polarization through PPAR-γ rather than STAT6 signal. In LPS-induced septic mice, FC-99 pretreated mice displayed lower expression of M1 markers together with the increased M2 marker CD206 and improvement of liver injury. These findings illustrated that FC-99 could promote M2 macrophage polarization via PPAR-γ signaling and seemed to be a potential therapeutic candidate for inflammatory liver injury.

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The N6-methyladenosine (m6A)-forming enzyme METTL3 facilitates M1 macrophage polarization through the methylation of STAT1 mRNA

AJP Cell Physiology ◽

10.1152/ajpcell.00212.2019 ◽

2019 ◽

Vol 317 (4) ◽

pp. C762-C775 ◽

Cited By ~ 9

Author(s):

Yihan Liu ◽

Zhujiang Liu ◽

Hao Tang ◽

Yicong Shen ◽

Ze Gong ◽

...

Keyword(s):

Epigenetic Modification ◽

Macrophage Polarization ◽

M2 Macrophage ◽

M1 Polarization ◽

M1 Macrophage ◽

Mouse Macrophages ◽

Rna Immunoprecipitation ◽

M2 Macrophage Polarization ◽

Plasmid Transfection

Compelling evidence indicates that epigenetic regulations orchestrate dynamic macrophage polarization. N6-methyladenosine (m6A) methylation is the most abundant epigenetic modification of mammalian mRNA, but its role in macrophage polarization is still completely unknown. Here, we show that the m6A-catalytic enzyme methyltransferase like 3 (METTL3) is specifically upregulated following the M1 polarization of mouse macrophages. Furthermore, METTL3 knockdown through siRNA transfection markedly inhibited M1, but enhanced M2, macrophage polarization. Conversely, its overexpression via plasmid transfection greatly facilitated M1, but attenuated M2, macrophage polarization. Further methylated RNA immunoprecipitation and in vitro m6A methylation assays suggested that METTL3 directly methylates mRNA encoding signal transducer and activator of transcription 1 (STAT1), a master transcription factor controlling M1 macrophage polarization, at its coding sequence and 3′-untranslated regions. In addition, METTL3-mediated STAT1 mRNA methylation significantly increased mRNA stability and subsequently upregulated STAT1 expression. In conclusion, METTL3 drives M1 macrophage polarization by directly methylating STAT1 mRNA, potentially serving as an anti-inflammatory target.

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CircN4bp1 Facilitates Sepsis-Induced Acute Respiratory Distress Syndrome Through Mediating Macrophage Polarization via the miR-138-5p/EZH2 Axis

10.21203/rs.3.rs-915755/v1 ◽

2021 ◽

Author(s):

Dongyang Zhao ◽

Chunxue Wang ◽

Xiandong Liu ◽

Na Liu ◽

Shougang Zhuang ◽

...

Keyword(s):

Macrophage Activation ◽

Rna Binding ◽

Macrophage Polarization ◽

Expression Patterns ◽

Cecal Ligation ◽

Luciferase Reporter ◽

Mice Model ◽

Quantitative Expression ◽

M1 Macrophage

Abstract Background We recently reported the differential circRNAs expression patterns of the pulmonary macrophages in sepsis induced ARDS mice model by microarray analysis; However, their function and hidden molecular mechanism in regulation of macrophage activation and inflammation remains poorly understood. Methods In this study, serum were obtained from ARDS patients post sepsis and control subjects. Mice were subjected to Cecal ligation and puncture (CLP) surgery and intravenously injected with si-circN4bp1 plasmid transfected macrophages. Raw264.7 cells and MH-S cells were transfected with circN4bp1 overexpression or silence vectors and then polarized as M1 or M2 macrophages in vitro. Results We firstly examined the quantitative expression and localization of circN4bp1 in macrophages by Real-time PCR and fluorescence in situ hybridization (FISH), and found that circN4bp1 was overexpressed in PBMC and monocytes and its expression levels were correlated with a poor prognosis in ARDS patients induced by sepsis. In CLP-induced ARDS mice, we demonstrated that knockdown of circN4bp1 inhibited the lung injury and inflammatory cytokine release, and improved the long-time survival through blunting the M1 macrophage activation. Moreover, bioinformatics analysis predicated a circN4bp1/miR-138-5p ceRNA network, which was confirmed by Luciferase reporter assay and RNA binding protein immunoprecipitation (RIP). In vitro experiments, we indicated that circN4bp1 affected macrophage differentiation by binding to miR-138-5p, thus regulating the expression of EZH2. Lastly, we found that the m6A level of circN4bp1 was elevated in ARDS mice; inhibition of m6A methyltransferases METTL3 blocked this response in vitro. Conclusions These data suggest that circN4bp1 can function as a miR-138-5p sponge for the regulation of macrophage polarization and may serve as a potential target and/or prognostic marker for ARDS patients following sepsis.

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Histone lactylation drives oncogenesis by facilitating m6A reader protein YTHDF2 expression in ocular melanoma

Genome Biology ◽

10.1186/s13059-021-02308-z ◽

2021 ◽

Vol 22 (1) ◽

Author(s):

Jie Yu ◽

Peiwei Chai ◽

Minyue Xie ◽

Shengfang Ge ◽

Jing Ruan ◽

...

Keyword(s):

Macrophage Polarization ◽

Regulation Of Gene Expression ◽

Metabolic Stress ◽

Ocular Melanoma ◽

Rna Modifications ◽

M1 Macrophage ◽

Melanoma Therapy

Abstract Background Histone lactylation, a metabolic stress-related histone modification, plays an important role in the regulation of gene expression during M1 macrophage polarization. However, the role of histone lactylation in tumorigenesis remains unclear. Results Here, we show histone lactylation is elevated in tumors and is associated with poor prognosis of ocular melanoma. Target correction of aberrant histone lactylation triggers therapeutic efficacy both in vitro and in vivo. Mechanistically, histone lactylation contributes to tumorigenesis by facilitating YTHDF2 expression. Moreover, YTHDF2 recognizes the m6A modified PER1 and TP53 mRNAs and promotes their degradation, which accelerates tumorigenesis of ocular melanoma. Conclusion We reveal the oncogenic role of histone lactylation, thereby providing novel therapeutic targets for ocular melanoma therapy. We also bridge histone modifications with RNA modifications, which provides novel understanding of epigenetic regulation in tumorigenesis.

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In vivo and In vitro PPAR-y Activation Decreases M1-Macrophage Polarization and Improves Liver Ischemia Reperfusion Injury

Transplantation Journal ◽

10.1097/01.tp.0000543674.85457.9b ◽

2018 ◽

Vol 102 ◽

pp. S708

Author(s):

Ivan Linares ◽

Agata Bartczak ◽

Kaveh Farrokhi ◽

Dagmar Kollmann ◽

Moritz Kaths ◽

...

Keyword(s):

Reperfusion Injury ◽

Ischemia Reperfusion Injury ◽

Ischemia Reperfusion ◽

Macrophage Polarization ◽

Liver Ischemia ◽

M1 Macrophage

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847 Inflammasome activation in M2 macrophage restrain the immune suppressive function

Journal for ImmunoTherapy of Cancer ◽

10.1136/jitc-2020-sitc2020.0847 ◽

2020 ◽

Vol 8 (Suppl 3) ◽

pp. A900-A900

Author(s):

Ronghua Zhang ◽

Tienan Wang ◽

Qing Lin

Keyword(s):

T Cell ◽

T Cell Activation ◽

Culture System ◽

Cell Activation ◽

Macrophage Polarization ◽

Inflammasome Activation ◽

M2 Macrophage ◽

M1 Macrophage ◽

Suppressive Phenotype

BackgroundMacrophage is an important component in tumor microenvironment (TME) and plays multiple roles in tumor initiation, progression and metastases. In response to various stimuli within TME, macrophage exhibits high level of functional heterogeneity. There are two distinct groups of macrophages: M1 macrophage exhibits pro-inflammatory phenotype with high levels of TNF-a, IL-6, and IL-1ß, while M2 macrophage displays immune suppressive phenotype with high levels of anti-inflammatory cytokines such as IL-10 and TGF-ß. In response to the M2 cytokines, myeloid cells within the TME further acquire higher expression of PD-L1 and thus inactivate T cells. M2 cytokines can also directly inhibit T cell activation. As a result, re-polarizing M2 macrophages becomes a key concept for cancer immunotherapy. The NLRP3 inflammasome is acquired by macrophages to fight against endogenous danger signals. Macrophage NLRP3 activation has been observed in several tumor models, but the function of NLRP3 on macrophage polarity remains controversial. Inflammasome activation with IL-1ß/IL-18 secretion was reported to promote M1 polarization. However, NLRP3 activation was also reported to promote M2 polarity through up-regulation of IL4 in asthma modelMethodsHere, we have established an in vitro human macrophage NLRP3 activation system (figure 1), coupled with M2 macrophage polarization assay, to dissect the role of NLRP3 in macrophage phenotype.ResultsOur results indicate that NLRP3 activation restrained M2 phenotype and further enhanced T cell activation in an M2/T cell co-culture system (figure 2).Abstract 847 Figure 1Inflammasome activation polarize M2 macrophage intUse LPS/ATP to stimulate NLRP3 in M2 macrophage and demonstrate NLRP3 activation could reduce CD163 and increase CD86Abstract 847 Figure 2Inflammasome in M2 rescue T cell activationestablish M2/T co-culture system in vitro to demonstrate M2 could suppress T activation while Inflammatory M2 could partial rescue the suppressive phenotypeConclusionsInflammasome could be the potential target for cancer by modulating T cell activation through macrophage polarization regulation

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Fargesin ameliorates osteoarthritis via macrophage reprogramming by downregulating MAPK and NF-κB pathways

10.21203/rs.3.rs-60253/v1 ◽

2020 ◽

Author(s):

Jiansen Lu ◽

Hongbo Zhang ◽

Jianying Pan ◽

Zhiqiang Hu ◽

Liangliang Liu ◽

...

Keyword(s):

Macrophage Polarization ◽

In Vitro Study ◽

Cartilage Degeneration ◽

Research Society ◽

Preventive Strategy ◽

Protective Effects ◽

Erk Mapk ◽

M1 Macrophage ◽

Main Components

Abstract Synovial macrophage polarization and interactions between chondrocytes and macrophages are essential for osteoarthritis (OA) development. The present study determined the role and regulatory mechanisms of fargesin, one of the main components of Magnolia fargesii, in macrophage reprogramming and crosstalk across cartilage and synovium. 10-week-old male C57BL/6 mice were randomly assigned to sham-operated, collagenase-induced OA (CIOA)-operated, or CIOA-operated with intraarticular fargesin treatment groups. Fargesin attenuated articular cartilage degeneration and synovitis, resulting in substantially lower Osteoarthritis Research Society International (OARSI) and synovitis scores. In particular, significantly increased M2 polarization and decreased M1 polarization in synovial macrophages were found in fargesin-treated CIOA mice compared to controls. This was accompanied by down-regulation of IL-6 and IL-1β and upregulation of IL-10 in serum. Although conditioned medium (CM) from the M1 macrophage treated with fargesin reduced the expression of matrix metalloproteinase-13, RUNX2, and type X collagen X in OA cartilage, it had no direct effect on chondrocyte metabolism in an in vitro study. Moreover, fargesin exerted protective effects by suppressing p38/ERK MAPK and p65/NF-κB signaling. This study showed that fargesin switched the polarized phenotypes of macrophages from M1 to M2 subtypes and prevented cartilage degeneration partially by down-regulating p38/ERK MAPK and p65/NF-κB signaling. Targeting macrophage reprogramming or blocking the crosstalk between macrophages and chondrocytes in early OA may be an effective preventive strategy.

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miR-657 Promotes Macrophage Polarization toward M1 by Targeting FAM46C in Gestational Diabetes Mellitus

Mediators of Inflammation ◽

10.1155/2019/4851214 ◽

2019 ◽

Vol 2019 ◽

pp. 1-9

Author(s):

Pingping Wang ◽

Zengfang Wang ◽

Guojie Liu ◽

Chengwen Jin ◽

Quan Zhang ◽

...

Keyword(s):

Diabetes Mellitus ◽

Gestational Diabetes ◽

Gestational Diabetes Mellitus ◽

Macrophage Polarization ◽

Vital Role ◽

Luciferase Reporter ◽

M2 Macrophage ◽

And Migration

MicroRNA (miRNA) has been widely suggested to play a vital role of in the pathogenesis of gestational diabetes mellitus (GDM). We have previously demonstrated that miR-657 can regulate macrophage inflammatory response in GDM. However, the role of miR-657 on M1/M2 macrophage polarization in GDM pathogenesis is not clear yet. This study is aimed at elucidating this issue and identifying novel potential GDM therapeutic targets based on miRNA network. miR-657 is found to be upregulated in placental macrophages demonstrated by real-time PCR, which can enhance macrophage proliferation and migration in vitro. Luciferase reporter assay shows the evidence that FAM46C is a target of miR-657. In addition, miR-657 can promote macrophage polarization toward the M1 phenotype by downregulating FAM46C in macrophages. The present study strongly suggests miR-657 is involved in GDM pathogenesis by regulating macrophage proliferation, migration, and polarization via targeting FAM46C. miR-657/FAM46C may serve as promising targets for GDM diagnosis and treatment.

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The gut microbial metabolite trimethylamine N-oxide aggravates GVHD by inducing M1 macrophage polarization in mice

Blood ◽

10.1182/blood.2019003990 ◽

2020 ◽

Vol 136 (4) ◽

pp. 501-515 ◽

Cited By ~ 8

Author(s):

Kunpeng Wu ◽

Yan Yuan ◽

Huihui Yu ◽

Xin Dai ◽

Shu Wang ◽

...

Keyword(s):

Nlrp3 Inflammasome ◽

Macrophage Polarization ◽

Short Chain Fatty Acids ◽

Inflammasome Activation ◽

Microbial Metabolites ◽

M1 Macrophage ◽

The Impact

Abstract The diversity of the human microbiome heralds the difference of the impact that gut microbial metabolites exert on allogenic graft-versus-host (GVH) disease (GVHD), even though short-chain fatty acids and indole were demonstrated to reduce its severity. In this study, we dissected the role of choline-metabolized trimethylamine N-oxide (TMAO) in the GVHD process. Either TMAO or a high-choline diet enhanced the allogenic GVH reaction, whereas the analog of choline, 3,3-dimethyl-1-butanol reversed TMAO-induced GVHD severity. Interestingly, TMAO-induced alloreactive T-cell proliferation and differentiation into T-helper (Th) subtypes was seen in GVHD mice but not in in vitro cultures. We thus investigated the role of macrophage polarization, which was absent from the in vitro culture system. F4/80+CD11b+CD16/32+ M1 macrophage and signature genes, IL-1β, IL-6, TNF-α, CXCL9, and CXCL10, were increased in TMAO-induced GVHD tissues and in TMAO-cultured bone marrow–derived macrophages (BMDMs). Inhibition of the NLRP3 inflammasome reversed TMAO-stimulated M1 features, indicating that NLRP3 is the key proteolytic activator involved in the macrophage’s response to TMAO stimulation. Consistently, mitochondrial reactive oxygen species and enhanced NF-κB nuclear relocalization were investigated in TMAO-stimulated BMDMs. In vivo depletion of NLRP3 in GVHD recipients not only blocked M1 polarization but also reversed GVHD severity in the presence of TMAO treatment. In conclusion, our data revealed that TMAO-induced GVHD progression resulted from Th1 and Th17 differentiation, which is mediated by the polarized M1 macrophage requiring NLRP3 inflammasome activation. It provides the link among the host choline diet, microbial metabolites, and GVH reaction, shedding light on alleviating GVHD by controlling choline intake.

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