Emodin inhibits M1 macrophage activation that related to acute and chronic kidney injury through EGFR/MAPK pathway.

BACKGROUND: Macrophages are the main inflammatory cells involved in kidney injury and play a significant role in the development of acute kidney injury (AKI) and progression of chronic kidney disease (CKD). Emodin is believed to stabilize macrophage homeostasis under pathological conditions. The objective of this study aimed to explore the underlying mechanisms and effects of Emodin on M1 macrophages. METHODS: Network pharmacology methods were used to predict target proteins associated with renal injury and identify the pathways affected by emodin. RAW264.7 macrophages were induced into M1 polarization using LPS and then treated with emodin at 20, 40, and 80 µM. The effects of emodin on cell viability, cytokines (IL-1ß, IL-6, TNF-α), M1 macrophage markers (F4/80 + CD86+), and the EGFR/MAPK pathway were evaluated. Additionally, we transfected RAW264.7 cells with an EGFR shRNA interference lentivirus to assess its effects on RAW264.7 cells function and MAPK pathway. After RAW264.7 cells were passaged to expanded culture and transfected with EGFR-interfering plasmid, macrophages were induced to polarize towards M1 with LPS and then treated with 80 µM emodin. CKD modeling was performed to test how emodin is regulated during CKD. RESULTS: There are 15 common targets between emodin and kidney injury, of which the EGFR/MAPK pathway is the pathway through which emodin affects macrophage function. Emodin significantly reduced the levels of IL-6, IL-1ß and TNF-α (p < 0.05) and the ratio of M1 macrophage surface markers F4/80 + CD86+ (p < 0.01) in the supernatant of RAW264.7 cells in a dose-dependent manner. Furthermore, the inhibitory effect of emodin on RAW264.7 cells was achieved by interfering with the EGFR/MAPK pathway. Moreover, emodin also affected the mRNA and protein expression of EGFR and Ras, leading to a decrease in the rate of M1 macrophages, thus inhibiting the pro-inflammatory effect of M1 macrophages. The addition of emodin reduced the rate of M1 macrophages in CKD and inhibited the further polarization of M1 macrophages, thus maintaining the pro-inflammatory and anti-inflammatory homeostasis in CKD, and these effects were achieved by emodin through the control of the EGRF/ERK pathway. CONCLUSION: Emodin attenuates M1 macrophage polarization and pro-inflammatory responses via the EGFR/MAPK signalling pathway. And the addition of emodin maintains pro- and anti-inflammatory homeostasis, which is important for maintaining organ function and tissue repair.

Microvesicles-delivering Smad7 have advantages over microvesicles in suppressing fibroblast differentiation in a model of Peyronie's disease.

BACKGROUND: This study compared the differences of microvesicles (MVs) and microvesicles-delivering Smad7 (Smad7-MVs) on macrophage M1 polarization and fibroblast differentiation in a model of Peyronie's disease (PD). METHODS: Overexpression of Smad7 in rat BMSCs was obtained by pCMV5-Smad7 transfection. MVs were collected from rat BMSCs using ultracentrifugation. In cells, 100 µg/mL of MVs or Smad7-MVs were used to treat the 100 ng/mL of lipopolysaccharide (LPS)-induced RAW264.7 cells or 10 ng/mL of recombinant transforming growth factor-ß1 (TGF-ß1)-induced fibroblasts. The pro-inflammatory cytokines and markers of M1 macrophages were measured in RAW264.7 cells, and the migration and markers of fibroblast differentiation were measured in fibroblasts. In rats, 50 µg of MVs or Smad7-MVs were used to treat the TGF-ß1-induced animals. The pathology of tunica albuginea (TA), the markers of M1 macrophages and fibroblast differentiation in the TA were measured. RESULTS: The MVs or Smad7-MVs treatment suppressed the LPS-induced macrophage M1 polarization and TGF-ß1-induced fibroblast differentiation. Moreover, the Smad7-MVs treatment decreased the fibroblast differentiation compared with the MVs treatment. In the TGF-ß1-induced TA of rats, MVs or Smad7-MVs treatment ameliorated the TA fibrosis by suppressing the macrophage M1 polarization and fibroblast differentiation. There was no significance on the M1-polarized macrophages between the MVs treatment and the Smad7-MVs treatment. Meanwhile, the Smad7-MVs treatment had an edge in terms of suppressing the fibroblast differentiation in the TGF-ß1-induced PD model compared with the MVs treatment. CONCLUSIONS: This study demonstrated that Smad7-MVs treatment had advantages over MVs treatment in suppressing of fibroblast differentiation in a model of PD.

Potency assay to predict the anti-inflammatory capacity of a cell therapy product for macrophage-driven diseases: overcoming the challenges of assay development and validation.

BACKGROUND: Given the high level of product complexity and limited regulatory guidance, designing and implementing appropriate potency assays is often the most challenging part of establishing a quality control testing matrix for a cell-based medicinal product. Among the most elusive tasks are the selection of suitable read-out parameters, the development of assay designs that most closely model the pathophysiological conditions, and the validation of the methods. Here we describe these challenges and how they were addressed in developing an assay that measures the anti-inflammatory potency of mesenchymal stromal cells (MSCs) in an M1 macrophage-dominated inflammatory environment. METHODS: An in vitro inflammation model was established by coculturing skin-derived ABCB5+ MSCs with THP-1 monocyte-derived M1-polarized macrophages. Readout was the amount of interleukin 1 receptor antagonist (IL-1RA) secreted by the MSCs in the coculture, measured by an enzyme-linked immunosorbent assay. RESULTS: IL-1RA was quantified with guideline-concordant selectivity, accuracy and precision over a relevant concentration range. Consistent induction of the macrophage markers CD36 and CD80 indicated successful macrophage differentiation and M1 polarization of THP-1 cells, which was functionally confirmed by release of proinflammatory tumor necrosis factor α. Testing a wide range of MSC/macrophage ratios revealed the optimal ratio for near-maximal stimulation of MSCs to secrete IL-1RA, providing absolute maximum levels per individual MSC that can be used for future comparison with clinical efficacy. Batch release testing of 71 consecutively manufactured MSC batches showed a low overall failure rate and a high comparability between donors. CONCLUSIONS: We describe the systematic development and validation of a therapeutically relevant, straightforward, robust and reproducible potency assay to measure the immunomodulatory capacity of MSCs in M1 macrophage-driven inflammation. The insights into the challenges and how they were addressed may also be helpful to developers of potency assays related to other cellular functions and clinical indications.

Fritillaria cirrhosa D. Don Alleviates Inflammatory Progression and Suppresses M1 Polarization of Macrophages in Chronic Obstructive Pulmonary Disease.

INTRODUCTION: Chronic obstructive pulmonary disease (COPD) is a progressive and largely irreversible disease. Current therapeutic approaches for COPD are limited in terms of slowing disease progression and suppressing pulmonary inflammation. Therefore, this study aimed to identify a method for alleviating inflammation in COPD. METHODS: A COPD-like mouse model was established and treated with or without Fritillaria cirrhosa D. Don (hereinafter referred to as Fritillaria). The expression levels of inflammatory cytokines in mouse serum were detected by using enzyme-linked immunosorbent assay (ELISA). Additionally, lung tissue was analyzed by hematoxylin-eosin staining and immunohistochemistry analysis, respectively. MLE-12 cells were exposed to cigarette smoke extract (CSE) and treated with or without Fritillaria. The MTT assay was conducted to assess cell viability. The activation of NF-κB p65 was determined by Western blotting (WB). Finally, flow cytometry was applied to analyze the M1 macrophage percentage. RESULTS: The results displayed that Fritillaria downregulated the levels of IL-1ß, IL-6, IL-8, and TNF-α in the COPD-like mouse serum and MLE-12 cells. Fritillaria alleviated the inflammatory response in lung tissue of COPD-like mice. The cell viability of MLE-12 cells considerably decreased when exposed to CSE, which could be restored by adding Fritillaria. The Fritillaria reduced the activation of the pro-inflammatory factor NF-κB p65 and inhibited M1 polarization of macrophages, thereby mitigating the inflammatory response. CONCLUSION: In conclusion, Fritillaria exhibits beneficial effects in suppressing pulmonary infection-related inflammation in both the COPD-like mouse model and in vitro cell experiments.

Therapeutic Effect of a Novel M1 Macrophage-Targeted Nanodrug in Chronic Periodontitis Mice.

Chronic periodontitis is a chronic, progressive, and destructive disease. Especially, the large accumulation of advanced glycation end products (AGEs) in a diseased body will aggravate the periodontal tissue damage, and AGEs induce M1 macrophages. In this project, the novel nanodrugs, glucose-PEG-PLGA@MCC950 (GLU@MCC), are designed to achieve active targeting with the help of glucose transporter 1 (GLUT1) which is highly expressed in M1 macrophages induced by AGEs. Then, the nanodrugs release MCC950, which is a kind of NLRP3 inhibitor. These nanodrugs not only can improve the water solubility of MCC950 but also exhibit superior characteristics, such as small size, stability, innocuity, etc. In vivo experiments showed that GLU@MCC could reduce periodontal tissue damage and inhibit cell apoptosis in periodontitis model mice. In vitro experiments verified that its mechanism of action might be closely related to the inhibition of the NLRP3 inflammatory factor in M1 macrophages. GLU@MCC could effectively reduce the damage to H400 cells caused by AGEs, decrease the expression of NLRP3, and also obviously reduce the M1-type macrophage pro-inflammatory factors such as IL-18, IL-1ß, caspase-1, and TNF-α. Meanwhile, the expression of anti-inflammatory factor Arg-1 in the M2 macrophage was increased. In brief, GLU@MCC would inhibit the expression of inflammatory factor NLRP3 and exert antiperiodontal tissue damage in chronic periodontitis via GLUT1 in the M1 macrophage as the gating target. This study provides a novel nanodrug for chronic periodontitis treatment.

Recombinantly expressed rhFEB remodeled the skin defect of db/db mice.

Fibronectin (FN) and collagen are vital components of the extracellular matrix (ECM). These proteins are essential for tissue formation and cell alignment during the wound healing stage. In particular, FN interacts with collagens to activate various intracellular signaling pathways to maintain ECM stability. A novel recombinant extra domain-B fibronectin (EDB-FN)-COL3A1 fusion protein (rhFEB) was designed to mimic the ECM to promote chronic and refractory skin ulcer wound healing. rhFEB significantly enhanced cell adhesion and migration, vascular ring formation, and the production of new collagen I (COL1A1) in vitro. rhFEB decreased M1 macrophages and further modulated the wound microenvironment, which was confirmed by the treatment of db/db mice with rhFEB. Accelerated wound healing was shown during the initial stages in rhFEB-treated db/db mice, as was enhanced follicle regeneration, re-epithelialization, collagen deposition, granulation, inflammation, and angiogenesis. The wound chronicity of diabetic foot ulcers (DFUs) remains the main challenge in current and future treatment. rhFEB may be a candidate molecule for regulating M1 macrophages during DFU healing. KEY POINTS: • A recombinant protein EDB-FN-collagen III (rhFEB) was highly expressed in Escherichia coli • rhFEB protein induces COL1A1 secretion in human skin fibroblasts • rhFEB protein accelerates diabetic wound healing.

The progression of inorganic nanoparticles and natural products for inflammatory bowel disease.

There is a growing body of evidence indicating a close association between inflammatory bowel disease (IBD) and disrupted intestinal homeostasis. Excessive production of reactive oxygen species (ROS) and reactive nitrogen species (RNS), along with an increase in M1 proinflammatory macrophage infiltration during the activation of intestinal inflammation, plays a pivotal role in disrupting intestinal homeostasis in IBD. The overabundance of ROS/RNS can cause intestinal tissue damage and the disruption of crucial gut proteins, which ultimately compromises the integrity of the intestinal barrier. The proliferation of M1 macrophages contributes to an exaggerated immune response, further compromising the intestinal immune barrier. Currently, intestinal nanomaterials have gained widespread attention in the context of IBD due to their notable characteristics, including the ability to specifically target regions of interest, clear excess ROS/RNS, and mimic biological enzymes. In this review, we initially elucidated the gut microenvironment in IBD. Subsequently, we delineate therapeutic strategies involving two distinct types of nanomedicine, namely inorganic nanoparticles and natural product nanomaterials. Finally, we present a comprehensive overview of the promising prospects associated with the application of nanomedicine in future clinical settings for the treatment of IBD (graphic abstract). Different classes of nanomedicine are used to treat IBD. This review primarily elucidates the current etiology of inflammatory bowel disease and explores two prominent nanomaterial-based therapeutic approaches. First, it aims to eliminate excessive reactive oxygen species and reactive nitrogen species. Second, they focus on modulating the polarization of inflammatory macrophages and reducing the proportion of pro-inflammatory macrophages. Additionally, this article delves into the treatment of inflammatory bowel disease using inorganic metal nanomaterials and natural product nanomaterials.

Message Transmission Between Adipocyte and Macrophage in Obesity.

Obesity is characterized by the chronic low-grade activation of the innate immune system. In this respect, macrophage-elicited metabolic inflammation and adipocyte-macrophage interaction have primary importance in obesity. Large quantity of macrophages is accumulated by different mechanisms in obese adipose tissue. Hypertrophic adipocyte-derived chemotactic monocyte chemoattractant protein-1 (MCP-1)/C-C chemokine receptor 2 (CCR2) pathway promotes more macrophage accumulation into the obese adipose tissue. However, obesity-induced changes in adipose tissue macrophage density are mainly dependent on increases in the triple-positive cluster of differentiation (CD)11b+ F4/80+ CD11c+ adipose tissue macrophage subpopulation. As epigenetic regulators, microRNAs (miRNAs) are one of the most important mediators of obesity. miRNAs are expressed by adipocytes as well as macrophages and regulate inflammation with the expression of target genes. A paracrine loop involving free fatty acids and tumor necrosis factor-alpha (TNF-α) between adipocytes and macrophages establishes a vicious cycle that aggravates inflammatory changes in the adipose tissue. Adipocyte-specific caspase-1 and production of interleukin-1beta (IL-1ß) by macrophages; both adipocyte and macrophage induction by toll-like receptor-4 (TLR4) through nuclear factor-kappaB (NF-κB) activation; free fatty acid-induced and TLR-mediated activation of c-Jun N-terminal kinase (JNK)-related pro-inflammatory pathways in CD11c+ immune cells; are effective in mutual message transmission between adipocyte and macrophage and in the development of adipose tissue inflammation. Thus, the metabolic status of adipocytes and their released exosomes are important determinants of macrophage inflammatory output. However, old adipocytes are removed by macrophages through trogocytosis or sending an "eat me" signal. As a single miRNA can be able to regulate a variety of target genes and signaling pathways, reciprocal transfer of miRNAs between adipocytes and macrophages via miRNA-loaded exosomes reorganizes the different stages of obesity. Changes in the expression of circulating miRNAs because of obesity progression or anti-obesity treatment indicate that miRNAs could be used as potential biomarkers. Therefore, it is believed that targeting macrophage-associated miRNAs with anti-obesity miRNA-loaded nano-carriers may be successful in the attenuation of both obesity and adipose tissue inflammation in clinical practice. Moreover, miRNA-containing exosomes and transferable mitochondria between the adipocyte and macrophage are investigated as new therapeutic targets for obesity-related metabolic disorders.

Macrophage polarization in human periapical lesions in relation to histopathological diagnosis, clinical features and lesion volume: An ex vivo study.

AIM: To evaluate M1 and M2 macrophage polarization in radicular cysts and periapical granulomas through an immunohistochemical analysis and the correlation between macrophage polarization and histopathological diagnosis, clinical characteristics and lesion volume using cone-beam computed tomography. METHODOLOGY: Periapical biopsies diagnosed as radicular cysts (n = 52) and periapical granulomas (n = 51) were analysed by immunohistochemical method. Teeth with periapical lesion with no history of root canal treatment (primary lesion) and lesions persistent to root canal treatment (persistent lesions) were included. Pathological diagnosis, patients' age, gender and clinical characteristics were obtained from treatment records. A cone-beam computed tomographic periapical volume index (CBCTPAVI) score was assigned to each periapical lesion based on the volume of the lesion. Immuno-expressions of CD68 and CD163 were quantified. The CD68/CD163 ratio was adopted to represent M1 or M2 macrophage polarization. Mann-Whitney U test was used to determine the different CD68/CD163 ratio between groups of radicular cyst and periapical granuloma. Spearman's correlation test was performed to assess the correlation between the CD68/CD163 ratio and lesion volume and CBCTPAVI score. RESULTS: Radicular cysts and periapical granulomas had CD68/CD163 median of 2.05 (IQR = 1.33) and 1.26 (IQR = 0.81), respectively. A significantly higher CD68/CD163 ratio was observed in radicular cysts (p < .001). In contrast, periapical granulomas had significantly lower median of CD68/CD163 ratio. Larger lesions had a higher median of CD68/CD163 ratio, while smaller lesions had lower median of CD68/CD163 ratio (p = .007, rs = .262). CD68/CD163 ratio was significantly correlated with the CBCTPAVI score in the overall periapical lesions (p = .002, rs = .306). The higher CD68/CD163 ratio in larger lesions indicated a higher degree of M1 polarization compared to smaller lesions. Regarding the pathological diagnosis, there was a significant positive correlation between CBCTPAVI score and CD68/CD163 ratio in periapical granulomas (p < .001, rs = .453), whereas the negative correlation was observed for radicular cysts (p < .001, rs = -.471). CONCLUSIONS: Periapical granulomas are characterized by a M2-dominant macrophage polarization, while radicular cysts have significantly higher M1 macrophages. The higher degree of M1 macrophage polarization was significantly correlated with larger volume and higher CBCTPAVI scores of overall periapical lesion and periapical granuloma.

Characterization of High and Low IFNG-Expressing Subgroups in Atopic Dermatitis.

Atopic dermatitis (AD) is one of the most common chronic inflammatory skin diseases, with an increasing number of targeted therapies available. While biologics to treat AD exclusively target the key cytokines of type 2 immunity, Janus kinase inhibitors target a broad variety of cytokines, including IFN-γ. To better stratify patients for optimal treatment outcomes, the identification and characterization of subgroups, especially with regard to their IFNG expression, is of great relevance, as the role of IFNG in AD has not yet been fully clarified. This study aims to define AD subgroups based on their lesional IFNG expression and to characterize them based on their gene expression, T cell secretome and clinical attributes. RNA from the lesional and non-lesional biopsies of 48 AD patients was analyzed by RNA sequencing. Based on IFNG gene expression and the release of IFN-γ by lesional T cells, this cohort was categorized into three IFNG groups (high, medium, and low) using unsupervised clustering. The low IFNG group showed features of extrinsic AD with a higher prevalence of atopic comorbidities and impaired epidermal lipid synthesis. In contrast, patients in the high IFNG group had a higher average age and an activation of additional pro-inflammatory pathways. On the cellular level, higher amounts of M1 macrophages and natural killer cell signaling were detected in the high IFNG group compared to the low IFNG group by a deconvolution algorithm. However, both groups shared a common dupilumab response gene signature, indicating that type 2 immunity is the dominant immune shift in both subgroups. In summary, high and low IFNG subgroups correspond to intrinsic and extrinsic AD classifications and might be considered in the future for evaluating therapeutic efficacy or non-responders.

Induction of the PERK-eIF2α-ATF4 Pathway in M1 Macrophages under Endoplasmic Reticulum Stress.

Translation inhibition can activate two cell death pathways. The first pathway is activated by translational aberrations, the second by endoplasmic reticulum (ER) stress. In this work, the effect of ribosome-inactivating protein type II (RIP-II) viscumin on M1 macrophages derived from the THP-1 cell line was investigated. The number of modified ribosomes was evaluated by real-time PCR. Transcriptome analysis revealed that viscumin induces the ER stress activated by the PERK sensor.

[Role of macrophage polarization in pulmonary diseases and intervention of traditional Chinese medicines].

As important immune cells, macrophages are a key factor involved in maintaining the homeostasis of the pulmonary microenvironment. Under different conditions, macrophages with high plasticity can be polarized into classically activated(M1) and selectively activated(M2) macrophages, which have pro-inflammatory and anti-inflammatory effects, respectively. M1/M2 phenotype is associated with the occurrence and development of pulmonary diseases. A variety of information molecules and cytokines involved in the polarization of macrophages play a role in regulating phenotypes in pulmonary diseases, and the phenotype transformation varies significantly in different diseases. This paper introduces the biological characteristics of macrophage polarization and expounds the roles of macrophage polarization in bronchial asthma, chronic obstructive pulmonary disease, acute lung injury, and pulmonary fibrosis. Moreover, the research progress in the regulation of macrophage polarization by the active components in traditional Chinese medicine(TCM) and the TCM compound prescriptions in the treatment of pulmonary diseases was reviewed. This review aims to explore the potential of macrophage polarization in regulating pulmonary inflammation and provide new ideas for related clinical research.

Regulation of alveolar macrophage death in pulmonary fibrosis: a review.

Pulmonary fibrosis (PF) is a disease in which excessive extracellular matrix (ECM) accumulation occurs in pulmonary mesenchyme, which induces the destruction of alveolar structures and poor prognosis. Macrophage death is responsible for ECM accumulation after alveolar epithelial injury in PF. Depending on the local micro-environments, macrophages can be polarized to either classically activated (M1) or alternatively activated (M2) macrophage phenotypes. In general, M1 macrophages can promote inflammation and sterilization, stop the continuous damage process and prevent excessive repair, while M2 macrophages are anti-inflammatory and promote tissue repair, and excessive M2 macrophage activity may inhibit the absorption and degradation of ECM. Emerging evidence has revealed that death forms such as pyroptosis mediated by inflammasome affect polarization direction and ultimately lead to the development of PF. Pharmacological manipulation of macrophages death signals may serve as a logical therapeutic strategy for PF. This review will focus on the current state of knowledge regarding the regulation and underlying mechanisms of macrophages and their mediators in the influence of macrophage death on the development of PF. We expect to provide help in developing effective therapeutic strategies in clinical settings.

Transcriptomic and proteomic profiling reveals distinct pathogenic features of peripheral non-classical monocytes in systemic lupus erythematosus.

Peripheral blood monocytes propagate inflammation in systemic lupus erythematosus (SLE). Three major populations of monocytes have been recognized namely classical (CM), intermediate (IM) and non-classical monocytes (NCM). Herein, we performed a comprehensive transcriptomic, proteomic and functional characterization of the three peripheral monocytic subsets from active SLE patients and healthy individuals. Our data demonstrate extensive molecular disruptions in circulating SLE NCM, characterized by enhanced inflammatory features such as deregulated DNA repair, cell cycle and heightened IFN signaling combined with differentiation and developmental cues. Enhanced DNA damage, elevated expression of p53, G0 arrest of cell cycle and increased autophagy stress the differentiation potential of NCM in SLE. This immunogenic profile is associated with an activated macrophage phenotype of NCM exhibiting M1 characteristics in the circulation, fueling the inflammatory response. Together, these findings identify circulating SLE NCM as a pathogenic cell type in the disease that could represent an additional therapeutic target.

Prognostic value of genetic aberrations and tumor immune microenvironment in primary acral melanoma.

BACKGROUND: Acral melanoma (AM) is the most common subtype in Chinese melanoma patients with a very poor prognosis. However, our understanding of the disease pathogenesis and molecular landscape is limited by the few studies that have been conducted. Here, we profiled the clinical characteristics, mutational landscapes and tumor immune microenvironment of AM patients to gain insights into disease characteristics and potential treatment strategies. METHODS: A total of 90 AM patients were enrolled and their tissue samples were subjected to next-generation sequencing and multiplexed immunohistochemistry tests. Kaplan-Meier curves and log-rank tests were used to analyze the prognostic potential of various genetic aberrations and immune cell compositions in AM. RESULTS: The median disease-free survival was 21.3 months and estimated median overall survival (OS) was 60 months. More advanced stages, older ages and thickness of greater than 4 mm were associated with worse prognosis in AM patients (HR = 2.57, 95% CI 1.25-5.29, p = 0.01; HR = 2.77, 95% CI 1.22-6.28, p = 0.02; HR = 3.43, 95% CI 1.51-7.82, p < 0.01, respectively), while patients who received post-surgical treatments had better survival (HR = 0.36, 95% CI 0.17-0.76, p = 0.01). The most frequently altered genes included BRAF (14.5%), KIT (16.9%), NRAS (12%), NF1 (10.8%), APC (7.2%), and ARID2 (6%). Copy number variations (CNV) were commonly found in CCND1 (19.3%), CDK4 (19.3%), MDM2 (14.5%) and FGF19 (12%). CDK4 amplifications was independently associated with shorter OS in AM patients (HR = 3.61, 95% CI 1.38-9.46, p = 0.01). CD8 + T cells (p < 0.001) and M1 macrophages (p = 0.05) were more highly enriched in the invasive margin than in the tumor center. Patients with higher levels of M1 macrophage infiltration in the invasive margin derived markedly longer OS (HR = 0.43, 95% CI 0.20-0.95, p = 0.03). Interestingly, in CDK4-amplified patients, there tended to be a low level of M1 macrophage infiltration in the invasive margin (p = 0.06), which likely explains the poor prognosis in such patients. CONCLUSIONS: Our study provided a comprehensive portrait of the clinicopathological features, genetic aberrations and tumor microenvironment profiles in AM patients and identified candidate prognostic factors, which may facilitate development of additional therapeutic options and better inform clinical management of AM patients. Based on these prognostic factors, further studies should focus on enhancing the infiltration of M1 macrophages, especially in CDK4-amplified AM patients.

Biofilm-forming strains of P. aeruginosa and S. aureus isolated from cystic fibrosis patients differently affect inflammatory phenotype of macrophages.

OBJECTIVE: Lung cystic fibrosis (CF) is characterized by chronic infections and hyperinflammatory response of neutrophils and macrophages. P. aeruginosa (PA) and S. aureus (MSSA, MRSA) are major pathogens of advanced CF. The main goal of this study was to compare the inflammatory phenotype of murine C57BL/6 macrophages exposed to PA57 with that exposed to MSSA60, both strains isolated from the same patient with severe CF. In the present study, we used C57BL/6 mice sensitive to lung infection with P. aeruginosa. METHODS: We measured the release of cytokines and the expression of phenotypic markers of murine neutrophils and macrophages exposed to bacterial cells and biofilm components (i.e., EPS) of the selected bacteria. In addition, a quantitative proteomic approach was used for the characterization of proteome-wide changes in macrophages. RESULTS: Neutrophils stimulated with PA57 and MSSA60 strains produced hyperinflammatory pattern of cytokines. The pro-inflammatory impact of PA57 was significantly higher than that of MSSA60 (IL-6/IL-10 ratio: PA57 = 9.3 vs. MSSA60 = 1.7). Macrophages produced significantly lower amount of cytokines, but showed classical pattern of M1 markers (iNOS-High; arginase-1 and mannose receptor MRC1-Low). Importantly, as evidenced by proteomic analysis, PA57 and PA57-EPS were stronger inducers of M1 macrophage polarization than the MSSA60 counterparts. CONCLUSIONS: Our study demonstrated that strong biofilm P. aeruginosa strains, CF isolates, are dominant inducers of M1 macrophages, termed biofilm-associated macrophages (BAMs). We suggest that repolarization of detrimental BAMs might be a new therapeutic strategy to ameliorate the airway damage in CF.

Critical contributions of protein cargos to the functions of macrophage-derived extracellular vesicles.

BACKGROUND: Macrophages are highly plastic innate immune cells that play key roles in host defense, tissue repair, and homeostasis maintenance. In response to divergent stimuli, macrophages rapidly alter their functions and manifest a wide polarization spectrum with two extremes: M1 or classical activation and M2 or alternative activation. Extracellular vesicles (EVs) secreted from differentially activated macrophages have been shown to have diverse functions, which are primarily attributed to their microRNA cargos. The role of protein cargos in these EVs remains largely unexplored. Therefore, in this study, we focused on the protein cargos in macrophage-derived EVs. RESULTS: Naïve murine bone marrow-derived macrophages were treated with lipopolysaccharide or interlukin-4 to induce M1 or M2 macrophages, respectively. The proteins of EVs and their parental macrophages were subjected to quantitative proteomics analyses, followed by bioinformatic analyses. The enriched proteins of M1-EVs were involved in proinflammatory pathways and those of M2-EVs were associated with immunomodulation and tissue remodeling. The signature proteins of EVs shared a limited subset of the proteins of their respective progenitor macrophages, but they covered many of the typical pathways and functions of their parental cells, suggesting their respective M1-like and M2-like phenotypes and functions. Experimental examination validated that protein cargos in M1- or M2-EVs induced M1 or M2 polarization, respectively. More importantly, proteins in M1-EVs promoted viability, proliferation, and activation of T lymphocytes, whereas proteins in M2-EVs potently protected the tight junction structure and barrier integrity of epithelial cells from disruption. Intravenous administration of M2-EVs in colitis mice led to their accumulation in the colon, alleviation of colonic inflammation, promotion of M2 macrophage polarization, and improvement of gut barrier functions. Protein cargos in M2-EVs played a key role in their protective function in colitis. CONCLUSION: This study has yielded a comprehensive unbiased dataset of protein cargos in macrophage-derived EVs, provided a systemic view of their potential functions, and highlighted the important engagement of protein cargos in the pathophysiological functions of these EVs.

Phytocannabinoids Reduce Inflammation of Primed Macrophages and Enteric Glial Cells: An In Vitro Study.

Intestinal inflammation is mediated by a subset of cells populating the intestine, such as enteric glial cells (EGC) and macrophages. Different studies indicate that phytocannabinoids could play a possible role in the treatment of inflammatory bowel disease (IBD) by relieving the symptoms involved in the disease. Phytocannabinoids act through the endocannabinoid system, which is distributed throughout the mammalian body in the cells of the immune system and in the intestinal cells. Our in vitro study analyzed the putative anti-inflammatory effect of nine selected pure cannabinoids in J774A1 macrophage cells and EGCs triggered to undergo inflammation with lipopolysaccharide (LPS). The anti-inflammatory effect of several phytocannabinoids was measured by their ability to reduce TNFα transcription and translation in J774A1 macrophages and to diminish S100B and GFAP secretion and transcription in EGCs. Our results demonstrate that THC at the lower concentrations tested exerted the most effective anti-inflammatory effect in both J774A1 macrophages and EGCs compared to the other phytocannabinoids tested herein. We then performed RNA-seq analysis of EGCs exposed to LPS in the presence or absence of THC or THC-COOH. Transcriptomic analysis of these EGCs revealed 23 differentially expressed genes (DEG) compared to the treatment with only LPS. Pretreatment with THC resulted in 26 DEG, and pretreatment with THC-COOH resulted in 25 DEG. To evaluate which biological pathways were affected by the different phytocannabinoid treatments, we used the Ingenuity platform. We show that THC treatment affects the mTOR and RAR signaling pathway, while THC-COOH mainly affects the IL6 signaling pathway.

Natural Isoforms of Listeria monocytogenes Virulence Factor Inlb Differ in c-Met Binding Efficiency and Differently Affect Uptake and Survival Listeria in Macrophage.

Listeria monocytogenes virulence factor InlB specifically interacts with the receptors c-Met and gC1q-R. Both receptors are present in non-professional and professional phagocytes, including macrophages. Phylogenetically defined InlB isoforms differently support invasion into non-professional phagocytes. This work deals with the effects of InlB isoforms on L. monocytogenes uptake and intracellular proliferation in human macrophages. Three isoforms of the receptor binding domain (idInlB) were derived from phylogenetically distinct L. monocytogenes strains belonging to the highly virulent CC1 (idInlBCC1), medium-virulence CC7 (idInlBCC7), and low-virulence CC9 (idInlBCC9) clonal complexes. The constant dissociation increased in the order idInlBCC1 << idInlBCC7 < idInlBCC9 for interactions with c-Met, and idInlBCC1 ≈ idInlBCC7 < idInlBCC9 for interactions with gC1q-R. The comparison of uptake and intracellular proliferation of isogenic recombinant strains which expressed full-length InlBs revealed that the strain expressing idInlBCC1 proliferated in macrophages twice as efficiently as other strains. Macrophage pretreatment with idInlBCC1 followed by recombinant L. monocytogenes infection disturbed macrophage functions decreasing pathogen uptake and improving its intracellular multiplication. Similar pretreatment with idInlBCC7 decreased bacterial uptake but also impaired intracellular multiplication. The obtained results demonstrated that InlB impaired macrophage functions in an idInlB isoform-dependent manner. These data suggest a novel InlB function in L. monocytogenes virulence.

Human Bone Marrow Mesenchymal Stem Cells Promote the M2 Phenotype in Macrophages Derived from STEMI Patients.

Acute ST-elevation myocardial infarction (STEMI) leads to myocardial injury or necrosis, and M1 macrophages play an important role in the inflammatory response. Bone marrow mesenchymal stem/stromal cells (BM-MSCs) are capable of modulating macrophage plasticity, principally due to their immunoregulatory capacity. In the present study, we analyzed the capacity of MSCs to modulate macrophages derived from monocytes from patients with STEMI. We analyzed the circulating levels of cytokines associated with M1 and M2 macrophages in patients with STEMI, and the levels of cytokines associated with M1 macrophages were significantly higher in patients with STEMI than in controls. BM-MSCs facilitate the generation of M1 and M2 macrophages. M1 macrophages cocultured with MSCs did not have decreased M1 marker expression, but these macrophages had an increased expression of markers of the M2 macrophage phenotype (CD14, CD163 and CD206) and IL-10 and IL-1Ra signaling-induced regulatory T cells (Tregs). M2 macrophages from patients with STEMI had an increased expression of M2 phenotypic markers in coculture with BM-MSCs, as well as an increased secretion of anti-inflammatory cytokines and an increased generation of Tregs. The findings in this study indicate that BM-MSCs have the ability to modulate the M1 macrophage response, which could improve cardiac tissue damage in patients with STEMI.