Abstract 19: Deletion of Myeloid GSK3α Attenuates Atherosclerosis and Promotes an M2 Macrophage Phenotype

2015 ◽  
Vol 35 (suppl_1) ◽  
Author(s):  
Cameron McAlpine ◽  
Aric Huang ◽  
Abby Emdin ◽  
Nicole Banko ◽  
Daniel Beriault ◽  
...  
Keyword(s):  
Glycogen Synthase ◽  
Macrophage Polarization ◽  
Myeloid Cells ◽  
Atherosclerotic Lesion ◽  
M2 Macrophage ◽  
Lesion Volume ◽  
Macrophage Phenotype ◽  
Expression Of Genes ◽  
M1 Macrophage ◽  
Deficient Mice

Objective: Glycogen synthase kinase (GSK)-3α/β has been implicated in the pathogenesis of diseases including diabetes, cancer, Alzheimer’s and atherosclerosis. The tissue and homolog specific functions of GSK3α and β in atherosclerosis are unknown. This study examines the effect of hepatocyte or myeloid cell specific deletion of GSK3α or GSK3β on atherosclerosis in LDLR-/- mice. Approach and results: We ablated GSK3α or GSK3β expression in hepatic or myeloid cells of LDLR-/- mice and mice were fed a high fat diet for 10 weeks. GSK3α or GSK3β deficiency in hepatic or myeloid cells did not affect metabolic parameters, including plasma lipid levels. Hepatic deletion of GSK3α or GSK3β did not affect the development of atherosclerosis or hepatic lipid content. Myeloid deletion of GSK3α, but not GSK3β, reduced atherosclerotic lesion volume as well as lesion complexity. Mice lacking GSK3α in myeloid cells had a less inflammatory and more anti-inflammatory plasma cytokine profile. Macrophages within atherosclerotic lesions of myeloid GSK3α deficient mice, but not GSK3β deficient mice, displayed reduced expression of markers associated with M1 macrophage polarization and enhanced expression of the M2 markers. Finally, bone marrow derived macrophages were isolated and differentiated into classical M1 macrophages or alternative M2 macrophages in vitro. GSK3α deletion, but not GSK3β deletion, attenuated the expression of genes associated with M1 polarization while promoting the expression of genes associated with M2 polarization. Mechanistically, GSK3α regulated macrophage polarization by modulating the phosphorylation and activation of STAT transcription factors. Conclusions: Our findings suggest that deletion of myeloid GSK3α attenuates the progression of atherosclerosis by regulating STAT activation and promoting an M2 macrophage phenotype.

scholarly journals Role of microRNA-21 and Its Underlying Mechanisms in Inflammatory Responses in Diabetic Wounds

2020 ◽  
Vol 21 (9) ◽  
pp. 3328 ◽  
Author(s):  
Cole Liechty ◽  
Junyi Hu ◽  
Liping Zhang ◽  
Kenneth W. Liechty ◽  
Junwang Xu
Keyword(s):  
Inflammatory Responses ◽  
Macrophage Polarization ◽  
Regulation Of Gene Expression ◽  
Mouse Skin ◽  
M2 Macrophage ◽  
Central Feature ◽  
Macrophage Phenotype ◽  
Macrophage Cells ◽  
M1 Macrophage ◽  
Diabetic Wounds

A central feature of diabetic wounds is the persistence of chronic inflammation, which is partly due to the prolonged presence of pro-inflammatory (M1) macrophages in diabetic wounds. Persistence of the M1 macrophage phenotype and failure to transition to the regenerative or pro-remodeling (M2) macrophage phenotype plays an indispensable role in diabetic wound impairment; however, the mechanism underlying this relationship remains unclear. Recently, microRNAs have been shown to provide an additional layer of regulation of gene expression. In particular, microRNA-21 (miR-21) is essential for an inflammatory immune response. We hypothesize that miR-21 plays a role in regulating inflammation by promoting M1 macrophage polarization and the production of reactive oxygen species (ROS). To test our hypothesis, we employed an in vivo mouse skin wound model in conjunction with an in vitro mouse model to assess miR-21 expression and macrophage polarization. First, we found that miR-21 exhibits a distinct expression pattern in each phase of healing in diabetic wounds. MiR-21 abundance was higher during early and late phases of wound repair in diabetic wounds, while it was significantly lower in the middle phase of wounding (at days 3 and 7 following wounding). In macrophage cells, M1 polarized macrophages exhibited an upregulation of miR-21, as well as the M1 and pro-inflammatory markers IL-1b, TNFa, iNos, IL-6, and IL-8. Overexpression of miR-21 in macrophage cells resulted in an upregulation of miR-21 and also increased expression of the M1 markers IL-1b, TNFa, iNos, and IL-6. Furthermore, hyperglycemia induced NOX2 expression and ROS production through the HG/miR-21/PI3K/NOX2/ROS signaling cascade. These findings provide evidence that miR-21 is involved in the regulation of inflammation. Dysregulation of miR-21 may explain the abnormal inflammation and persistent M1 macrophage polarization seen in diabetic wounds.

scholarly journals Weak UVB Irradiation Promotes Macrophage M2 Polarization and Stabilizes Atherosclerosis

2021 ◽  
Author(s):  
Xin-Yun Li ◽  
Tao Qin ◽  
Peng-Fei Zhang ◽  
Wen-jiang Yan ◽  
Ling-Li Lei ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Macrophage Polarization ◽  
Atherosclerotic Lesion ◽  
Ultraviolet B ◽  
M2 Macrophage ◽  
Uvb Irradiation ◽  
Plaque Stability ◽  
M1 Macrophage

AbstractAtherosclerosis (AS) is a chronic cardiovascular disease endangering human health and is one of the most common causes of myocardial infarction and stroke. Macrophage polarization plays a vital role in regulating plaque stability. As an important component of sunlight, ultraviolet B (UVB) has been proven to promote vitamin D and nitric oxide synthesis. This research used an AS model in ApoE−/− mice to study the effects of UVB on macrophage polarization and atherosclerotic plaque stability. In vitro, UVB irradiation increased arginase-I (Arg-I, M2 macrophage) and macrophage mannose receptor (CD206) expression, while the expression of inducible nitric oxide synthase (iNOS) (M1 macrophage) and CD86 was decreased. UVB promoted Akt phosphorylation in vitro. In vivo, UVB irradiation promoted the stabilization of atherosclerotic lesion plaques, while the phenotype of M2 macrophages increased. Our research provides new evidence for UVB in preventing and treating atherosclerosis.

scholarly journals PAK1 Silencing Attenuated Proinflammatory Macrophage Activation and Foam Cell Formation by Increasing PPARγ Expression

2021 ◽  
Vol 2021 ◽  
pp. 1-13
Author(s):  
Wen-Lin Cheng ◽  
Quan Zhang ◽  
Bo Li ◽  
Jian-Lei Cao ◽  
Lin Jiao ◽  
...  
Keyword(s):  
Macrophage Activation ◽  
Foam Cell ◽  
Macrophage Polarization ◽  
Cell Formation ◽  
Foam Cell Formation ◽  
M2 Macrophage ◽  
Macrophage Phenotype ◽  
Loss Of Function ◽  
M1 Macrophage ◽  
Pparγ Expression

Macrophage polarization in response to environmental cues has emerged as an important event in the development of atherosclerosis. Compelling evidences suggest that P21-activated kinases 1 (PAK1) is involved in a wide variety of diseases. However, the potential role and mechanism of PAK1 in regulation of macrophage polarization remains to be elucidated. Here, we observed that PAK1 showed a dramatically increased expression in M1 macrophages but decreased expression in M2 macrophages by using a well-established in vitro model to study heterogeneity of macrophage polarization. Adenovirus-mediated loss-of-function approach demonstrated that PAK1 silencing induced an M2 macrophage phenotype-associated gene profiles but repressed the phenotypic markers related to M1 macrophage polarization. Additionally, dramatically decreased foam cell formation was found in PAK1 silencing-induced M2 macrophage activation which was accompanied with alternation of marker account for cholesterol efflux or influx from macrophage foam cells. Moderate results in lipid metabolism and foam cell formation were found in M1 macrophage activation mediated by AdshPAK1. Importantly, we presented mechanistic evidence that PAK1 knockdown promoted the expression of PPARγ, and the effect of macrophage activation regulated by PAK1 silencing was largely reversed when a PPARγ antagonist was utilized. Collectively, these findings reveal that PAK1 is an independent effector of macrophage polarization at least partially attributed to regulation of PPARγ expression, which suggested PAK1-PPARγ axis as a novel therapeutic strategy in atherosclerosis management.

scholarly journals Effect of Platelet-Rich Plasma on M1/M2 Macrophage Polarization

2021 ◽  
Vol 22 (5) ◽  
pp. 2336
Author(s):  
Ryoka Uchiyama ◽  
Eriko Toyoda ◽  
Miki Maehara ◽  
Shiho Wasai ◽  
Haruka Omura ◽  
...  
Keyword(s):  
Culture Media ◽  
Platelet Rich Plasma ◽  
Point Of Care ◽  
Macrophage Polarization ◽  
Osteoarthritis Of The Knee ◽  
M2 Macrophage ◽  
Related Factors ◽  
Humoral Factors ◽  
M1 Macrophage ◽  
M2 Macrophage Polarization

Osteoarthritis of the knee (OAK) is a chronic degenerative disease and progresses with an imbalance of cytokines and macrophages in the joint. Studies regarding the use of platelet-rich plasma (PRP) as a point-of-care treatment for OAK have reported on its effect on tissue repair and suppression of inflammation but few have reported on its effect on macrophages and macrophage polarization. Based on our clinical experience with two types of PRP kits Cellaid Serum Collection Set P type kit (leukocyte-poor-PRP) and an Autologous Protein Solution kit (APS leukocyte-rich-PRP), we investigated the concentrations of humoral factors in PRPs prepared from the two kits and the effect of humoral factors on macrophage phenotypes. We found that the concentrations of cell components and humoral factors differed between PRPs purified using the two kits; APS had a higher concentration of M1 and M2 macrophage related factors. The addition of PRP supernatants to the culture media of monocyte-derived macrophages and M1 polarized macrophages revealed that PRPs suppressed M1 macrophage polarization and promoted M2 macrophage polarization. This research is the first to report the effect of PRPs purified using commercial kits on macrophage polarization.

847 Inflammasome activation in M2 macrophage restrain the immune suppressive function

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

scholarly journals Analysis of the Influence of Jaw Periosteal Cells on Macrophages Phenotype Using an Innovative Horizontal Coculture System

Biomedicines ◽  
2021 ◽  
Vol 9 (12) ◽  
pp. 1753
Author(s):  
Fang He ◽  
Felix Umrath ◽  
Christiane von Ohle ◽  
Siegmar Reinert ◽  
Dorothea Alexander
Keyword(s):  
Macrophage Polarization ◽  
Maxillofacial Surgery ◽  
Inflammatory Factors ◽  
Osteogenic Potential ◽  
Oral And Maxillofacial Surgery ◽  
M2 Macrophage ◽  
Macrophage Phenotype ◽  
Flow Cytometric ◽  
Coculture System ◽  
Gene And Protein Expression

Jaw periosteum-derived mesenchymal stem cells (JPCs) represent a promising cell source for bone tissue engineering in oral and maxillofacial surgery due to their high osteogenic potential and good accessibility. Our previous work demonstrated that JPCs are able to regulate THP-1-derived macrophage polarization in a direct coculture model. In the present study, we used an innovative horizontal coculture system in order to understand the underlying paracrine effects of JPCs on macrophage phenotype polarization. Therefore, JPCs and THP-1-derived M1/M2 macrophages were cocultured in parallel chambers under the same conditions. After five days of horizontal coculture, flow cytometric, gene and protein expression analyses revealed inhibitory effects on costimulatory and proinflammatory molecules/factors as well as activating effects on anti-inflammatory factors in M1 macrophages, originating from multiple cytokines/chemokines released by untreated and osteogenically induced JPCs. A flow cytometric assessment of DNA synthesis reflected significantly decreased numbers of proliferating M1/M2 cells when cocultured with JPCs. In this study, we demonstrated that untreated and osteogenically induced JPCs are able to switch macrophage polarization from a classical M1 to an alternative M2-specific phenotype by paracrine secretion, and by inhibition of THP-1-derived M1/M2 macrophage proliferation.

Abstract 260: Apolipoprotein A-I Binding Protein Regulates Macrophage Polarization in Atherosclerosis

2016 ◽  
Vol 36 (suppl_1) ◽  
Author(s):  
Dina A Schneider ◽  
Longhou Fang ◽  
Yury I Miller
Keyword(s):  
Lipid Rafts ◽  
Lipid Accumulation ◽  
Cholesterol Efflux ◽  
Binding Protein ◽  
Macrophage Polarization ◽  
Atherosclerotic Lesion ◽  
Negative Regulator ◽  
High Cholesterol Diet ◽  
Apolipoprotein A ◽  
M1 Macrophage

Our laboratory recently demonstrated that Apolipoprotein A-I Binding Protein (AIBP), an evolutionarily conserved intracellular and secreted protein, mediates cholesterol efflux from endothelial cells, which in turn disrupts lipid rafts and limits angiogenic signaling. Since lipid rafts are implicated in multiple cell signal cascades, to better understand the in vivo role of AIBP our laboratory has generated Apoa1bp -/- mice. The Apoa1bp -/- mice exhibit increased levels of inflammatory cytokines, and have an increased content of M1 macrophages in white adipose tissue in comparison to wild type mice when challenged with a high fat diet. Since AIBP accelerates cholesterol efflux from macrophages to HDL, and vascular lipid accumulation and inflammation are key factors in atherosclerosis, we hypothesized that AIBP is atheroprotective by suppressing macrophage lipid accumulation and inflammatory M1 macrophage polarization. Immunohistochemistry shows that AIBP is present in atherosclerotic lesion macrophages. However, elicited macrophages lacking AIBP expression do not exhibit any impairment in their ability to polarize to M1, suggesting that deficiency in secreted extracellular AIBP may be responsible for the M1 phenotype observed in Apoa1bp -/- mice. Indeed, treating macrophages with recombinant AIBP prior to polarization resulted in suppression of M1 polarization. In a high-cholesterol diet feeding experiment, Apoa1bp -/- Ldlr -/- mice had increased M1 macrophage content in their aorta and aortic root atherosclerotic lesions, as determined by FACS and immunohistochemistry, respectively. In conclusion, AIBP is an important negative regulator of macrophage polarization and lipid accumulation. A better understanding of AIBP’s regulatory functions in the context of atherosclerosis will provide new mechanistic insights and targeted therapies.

scholarly journals Interleukin 26 Skews Macrophage Polarization Towards M1 Phenotype by Activating cJUN and the NF-κB Pathway

Cells ◽  
2020 ◽  
Vol 9 (4) ◽  
pp. 938
Author(s):  
Yi-Hsuan Lin ◽  
Yi-Hsun Wang ◽  
Yi-Jen Peng ◽  
Feng-Cheng Liu ◽  
Gu-Jiun Lin ◽  
...  
Keyword(s):  
Rheumatoid Arthritis ◽  
Messenger Rna ◽  
Molecular Mechanisms ◽  
Macrophage Polarization ◽  
Enzyme Linked Immunosorbent Assay ◽  
M2 Macrophage ◽  
Macrophage Differentiation ◽  
Macrophage Cells ◽  
M1 Macrophage ◽  
Interleukin 26

Interleukin 26 (IL-26) is a new member of the IL-10 family that is highly expressed in rheumatoid arthritis (RA). However, the functions of IL-26 produced by macrophages in RA have not been elucidated. In the present work, we evaluated the effects and the mechanisms of IL-26 on M1 and M2 macrophage differentiation. Human or mouse macrophage cells were treated with lipopolysaccharides (LPS), interferon gamma (IFNγ), or IL-4 alone or concurrently treated with IL-26 to monitor M1 or M2 macrophage subtypes. The expression level of M1 or M2 macrophage genes was evaluated by reverse transcription polymerase chain reaction (RT-PCR) and enzyme-linked immunosorbent assay (ELISA). The molecular mechanisms of downstream signaling activation during differentiation were investigated by immunoblotting assay. Our results found that IL-26 promoted macrophage cells from CD80+ M1 macrophage differentiation, not from the CD206+ M2 phenotype. The messenger RNA of M1-type macrophage markers tumor necrosis factor alpha (TNFα) and inducible nitric oxide synthase (iNOS) was up-regulated in the IL-26-treated group. Also, the M1-related proinflammatory cytokines TNFα and IL-6 were induced after IL-26 stimulation. Interestingly, IL-10, a cytokine marker of M2 macrophage, was also elevated after IL-26 stimulation. Moreover, the M1-like macrophage stimulated by IL-26 underwent cJUN, nuclear factor kappa B (NF-κB), and signal transducer and activator of transcription 1 (STAT1) activation. Our findings suggested the role of IL-26 in synovial macrophages of active rheumatoid arthritis and provided a new insight into IL-26 as a candidate therapeutic target in rheumatoid arthritis.

scholarly journals Crosstalk between adipocytes and M2 macrophages compensates for osteopenic phenotype in the Lrp5-deficient mice

2020 ◽  
pp. 153537022097232
Author(s):  
Lisha Li ◽  
Xuemin Qiu ◽  
Na Zhang ◽  
Yan Sun ◽  
Yan Wang ◽  
...  
Keyword(s):  
Bone Marrow ◽  
Wnt Signaling ◽  
Macrophage Polarization ◽  
Myeloid Cells ◽  
Osteogenic Potential ◽  
Enzyme Linked Immunosorbent Assay ◽  
Tartrate Resistant Acid Phosphatase ◽  
M2 Macrophage ◽  
M2 Macrophages ◽  
Alizarin Red

A loss-of-function mutation in the Lrp5 gene in mice leads to a low bone mass disorder due to the inhibition of the canonical Wnt signaling pathway; however, the role of bone marrow microenvironment in mice with this mutation remains unclear. In this study, we evaluated proliferation and osteogenic potential of mouse osteoblasts using the MTT assay and Alizarin red staining. The levels of alkaline phosphatase, tartrate-resistant acid phosphatase, and adiponectin in culture supernatants were measured using the enzyme-linked immunosorbent assay. Osteoclast bone resorbing activity was evaluated by toluidine staining and the number and area of bone resorption pits were determined. We observed increased osteogenesis in osteoblasts co-cultured with the BM-derived myeloid cells compared to the osteoblasts cultured alone. Mice with global Lrp5 deletion had a relatively higher bone density compared to the mice carrying osteoblast/osteocyte-specific Lrp5 deletion. An increased frequency of M2 macrophages and reduced expression of inflammatory cytokines were detected in the myeloid cells derived from the bone marrow of mice with global Lrp5 deletion. Higher adipogenic potential and elevated levels of adiponectin in the global Lrp5 deletion mice contributed to the preferential M2 macrophage polarization. Here, we identified a novel systemic regulatory mechanism of bone formation and degradation in mice with global Lrp5 deletion. This mechanism depends on a crosstalk between the adipocytes and M2 macrophages in the bone marrow and is responsible for partly rescuing osteopenia developed as a result of decreased Wnt signaling.

scholarly journals ECM1 is an essential factor for the determination of M1 macrophage polarization in IBD in response to LPS stimulation

2020 ◽  
Vol 117 (6) ◽  
pp. 3083-3092 ◽  
Author(s):  
Yaguang Zhang ◽  
Xuezhen Li ◽  
Zhongguang Luo ◽  
Liyan Ma ◽  
Songling Zhu ◽  
...  
Keyword(s):  
Matrix Protein ◽  
Intestinal Inflammation ◽  
Macrophage Polarization ◽  
Extracellular Matrix Protein ◽  
Mechanistic Study ◽  
Macrophage Phenotype ◽  
Inflammatory Conditions ◽  
Arginase 1 ◽  
M1 Macrophage ◽  
Macrophage Colony

Inflammatory bowel disease (IBD) comprises chronic relapsing disorders of the gastrointestinal tract characterized pathologically by intestinal inflammation and epithelial injury. Here, we uncover a function of extracellular matrix protein 1 (ECM1) in promoting the pathogenesis of human and mouse IBD. ECM1 was highly expressed in macrophages, particularly tissue-infiltrated macrophages under inflammatory conditions, and ECM1 expression was significantly induced during IBD progression. The macrophage-specific knockout of ECM1 resulted in increased arginase 1 (ARG1) expression and impaired polarization into the M1 macrophage phenotype after lipopolysaccharide (LPS) treatment. A mechanistic study showed that ECM1 can regulate M1 macrophage polarization through the granulocyte-macrophage colony-stimulating factor/STAT5 signaling pathway. Pathological changes in mice with dextran sodium sulfate-induced IBD were alleviated by the specific knockout of the ECM1 gene in macrophages. Taken together, our findings show that ECM1 has an important function in promoting M1 macrophage polarization, which is critical for controlling inflammation and tissue repair in the intestine.

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