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Septic lung injury is strongly associated with polarization of M1 macrophages and excessive cytokine release. Fibroblast growth factor (FGF) signaling plays a role in both processes. However, the impact of FGF2 deficiency on macrophage polarization and septic acute lung injury remains unclear. To investigate this, we obtained macrophages from FGF2 knockout mice and examined their polarization and inflammatory cytokine expression. We also eliminated endogenous macrophages using clodronate liposomes and administered FGF2 knockout or WT macrophages intravenously in conjunction with cecal ligation and puncture (CLP) surgery to induce sepsis. In vitro analysis by flow cytometry and real-time PCR analysis demonstrated that FGF2 deficiency resulted in increased expression of M1 markers (iNOS and CD86) and inflammatory cytokines (CXCL1, IL1β, and IL6), especially after LPS stimulation. Additionally, immunofluorescence demonstrated increased nuclear translocation of p65 NF-κB in FGF2 knockout macrophages and RNA-seq analysis showed enrichment of differentially expressed genes in the IL17 and TNFα inflammatory signaling pathways. Furthermore, in vivo experiments revealed that depletion of FGF2 in macrophages worsened sepsis-induced lung inflammation, lung vascular leak, and lung histological injury, accompanied by an increase in CD86-positive cells and apoptosis. Our study suggests that FGF2 deficiency in macrophages plays a critical role in the pathogenesis of septic ALI, possibly because of the enhanced M1 macrophage polarization and production of proinflammatory cytokines. These findings provide empirical evidence for potential therapeutic interventions targeting FGF2 signaling to modulate the polarization of M1 and M2 macrophages in the management of sepsis-induced acute lung injury. [ABSTRACT FROM AUTHOR]

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In the tumor microenvironment, macrophages play crucial roles resulting in tumor suppression and progression, depending on M1 and M2 macrophages, respectively. In particular, macrophage-derived exosomes modulate the gene expression of cancer cells by delivering miRNAs which downregulate specific genes. The communication between macrophages and cancer cells is especially important in immunogenic tumors such as melanoma, where the cancer pogression is significantly influenced by the surrounding immune cells. In this study, we identified that M1 macrophages secrete exosomal miR-29c-3p in the co-culture system with melanoma cells. Simultaneously, ENPP2, the target of miR-29c-3p, decreased in the melanoma cells which are co-cultured with M1 macrophages. Additionally, we observed that the reduction of ENPP2 alleviates melanoma cell migration and invasion, due to the changes of cholesterol metabolism and ECM remodeling. Based on these findings, we demonstrated that M1 macrophages suppress aggressiveness of melanoma cells via exosomal miR-29c-3p-mediated knock-down of ENPP2 in cancer cells. [ABSTRACT FROM AUTHOR]

Organ structure destruction and functional decline leading to failure due to fibrosis pose severe threats to the human health and life. Macrophages are important immune cells present in various tissues and organs. Under the influence of numerous factors and pathways, such as transforming growth factor-β1 (TGF-β1), Toll-like receptor 4 (TLR4) /nuclear factor-κB (NF-κB), Janus kinase (JAK) /signal transducer and activator of transcription (STAT), Notch signaling pathway, peroxisome proliferator-activated receptor (PPAR), and cAMP response element-binding protein (CREB), the macrophages may undergo polarization. In visceral organ fibrosis, the macrophage polarization signaling network, composed of single or multiple factors and pathways, is one of the crucial mechanisms regulating fibrosis. After polarization, the macrophages produce the chemokines and matrix metalloproteinase (MMP), which are related to promoting fibrosis, leading to the occurrence and development of fibrosis. The current research conducted domestically and internationally mainly focuses on the roles of macrophages in infection, tumors, and fibrosis, with few summaries on the mechanisms of macrophage polarization in fibrosis. This review summarizes the pathways involved in macrophage polarization and the mechanisms of macrophage polarization in organ fibrosis, and provide the basis for the targeted therapy of fibrosis. [ABSTRACT FROM AUTHOR]

Tumor-associated macrophages (TAMs) are inflammatory cells that are important components of the tumor microenvironment. TAMs are functionally heterogeneous and divided into two main subpopulations with distinct and opposite functions: M1 and M2 macrophages. The secretory function of TAMs is essential for combating infections, regulating immune responses, and promoting tissue repair. Extracellular vesicles (EVs) are nanovesicles that are secreted by cells. They play a crucial role in mediating intercellular information transfer between cells. EVs can be secreted by almost all types of cells, and they contain proteins, microRNAs, mRNAs, and even long non-coding RNAs (lncRNAs) that have been retained from the parental cell through the process of biogenesis. EVs can influence the function and behavior of target cells by delivering their contents, thus reflecting, to some extent, the characteristics of their parental cells. Here, we provide an overview of the role of M1 macrophages and their EVs in cancer therapy by exploring the impact of M1 macrophage-derived EVs (M1-EVs) on tumors by transferring small microRNAs. Additionally, we discuss the potential of M1-EVs as drug carriers and the possibility of reprogramming M2 macrophages into M1 macrophages for disease treatment. We propose that M1-EVs play a crucial role in cancer therapy by transferring microRNAs and loading them with drugs. Reprogramming M2 macrophages into M1 macrophages holds great promise in the treatment of cancers. [ABSTRACT FROM AUTHOR]

Prostate cancer (PCa) is a prevalent malignant neoplasm affecting the male reproductive system globally. However, the diagnostic and therapeutic approaches fall short of meeting the demands posed by PCa. Poor expression of miRNA-203 (miR-203) within PCa tissues and cells implies its potential utility as a diagnostic indicator for PCa. Exosomes (Exo), membranous vesicles released by various cells, are rich reservoirs of miRNAs. However, the presence of miR-203 presents within Exo derived from PCa cells remains unclarified. In this study, Exo was isolated from urine specimens collected from clinical PCa patients and LNCaP cells to detect miR-203 expression. Meanwhile, the impact of overexpressed miR-203 on M0 macrophages (mø) was analyzed. Subsequently, alterations in the proliferative, migratory, and invasive capacities of LNCaP cells were examined within a co-culture system featuring elevated miR-203 levels in both macrophages and LNCaP cells. Furthermore, the repercussions of miR-203 upregulation or inhibition were explored in a murine PCa tumor model. The results revealed that Exo manifested a circular or elliptical morphology, encapsulating a phospholipid bilayer approximately 100 nm in diameter. Notably, Exo readily infiltrated, with both Exo and miR-203-overexpressing Exo prompting macrophage polarization toward the M1 subtype. In the co-culture system, miR-203 exhibited pronounced suppression of LNCaP cell proliferation, migration, and invasion, while concurrently fostering apoptosis as compared with the LNCaP group (Control). In vivo experiments further disclosed that miR-203 greatly inhibited the growth of PCa tumors in nude mice. Markedly heightened expression of M1 macrophage markers such as IL-1β, IL-6, IL-12, CXCL9, and CXCL10 was observed within the tumor microenvironment following miR-203 intervention, as opposed to the model group. However, the introduction of miR-203 antagomir led to a reversal in tumor growth trends. This investigation indicates the presence of miR-203 within the urine of PCa patients and Exo originating from cells, and that miR-203 exerted antitumor effect by facilitating M1 macrophage polarization. Our study furnishes valuable insights into the potential applicability of miR-203 as a diagnostic biomarker and therapeutic target for PCa. [ABSTRACT FROM AUTHOR]

Aim: Lung cancer is the leading cause of cancer-related deaths worldwide. Non-small cell lung cancer (NSCLC) is the most common subtype. Despite recent advancements in diagnostics and therapies, only a small percentage of patients benefit from immunotherapies. This underscores the urgent need to identify prognostic biomarkers for accurately assessing outcomes and providing treatment recommendations for NSCLC patients. Single-cell RNA sequencing (scRNA-seq) has revealed the heterogeneity of tumor-associated macrophages. Macrophages consist of M0, M1, and M2 subsets. M1 macrophages are often associated with improved clinical outcomes in various malignancies. However, there are no systematic studies on risk biomarkers for prognosticating NSCLC. Methods: CIBERSORT was used to calculate the macrophage subset infiltration percentage in bulk RNA-seq data from TCGA and GEO. The M1-related module was identified using the WGCNA algorithm. Potential M1 macrophage prognosis-associated genes were defined as the overlapping genes between marker genes in the M1 subpopulation from scRNA-seq data and prognosis-associated genes in M1 infiltrating cells. Results: Four risk genes (ADAM19, ICAM3, WIPF1, and LAP3) were identified through LASSO and multivariate Cox regression analysis. Forest plots demonstrated that the scoring model was an independent risk factor. A nomogram was provided to predict the prognosis of NSCLC patients. Finally, we validated the four risk genes at the protein expression levels and for copy number variations. Conclusions: In summary, our studies identified four risk genes related to M1 macrophages and presented a risk-scoring system to predict the outcomes of patients with NSCLC by integrating bulk and single-cell data.

Abstract Septic lung injury is strongly associated with polarization of M1 macrophages and excessive cytokine release. Fibroblast growth factor (FGF) signaling plays a role in both processes. However, the impact of FGF2 deficiency on macrophage polarization and septic acute lung injury remains unclear. To investigate this, we obtained macrophages from FGF2 knockout mice and examined their polarization and inflammatory cytokine expression. We also eliminated endogenous macrophages using clodronate liposomes and administered FGF2 knockout or WT macrophages intravenously in conjunction with cecal ligation and puncture (CLP) surgery to induce sepsis. In vitro analysis by flow cytometry and real-time PCR analysis demonstrated that FGF2 deficiency resulted in increased expression of M1 markers (iNOS and CD86) and inflammatory cytokines (CXCL1, IL1β, and IL6), especially after LPS stimulation. Additionally, immunofluorescence demonstrated increased nuclear translocation of p65 NF-κB in FGF2 knockout macrophages and RNA-seq analysis showed enrichment of differentially expressed genes in the IL17 and TNFα inflammatory signaling pathways. Furthermore, in vivo experiments revealed that depletion of FGF2 in macrophages worsened sepsis-induced lung inflammation, lung vascular leak, and lung histological injury, accompanied by an increase in CD86-positive cells and apoptosis. Our study suggests that FGF2 deficiency in macrophages plays a critical role in the pathogenesis of septic ALI, possibly because of the enhanced M1 macrophage polarization and production of proinflammatory cytokines. These findings provide empirical evidence for potential therapeutic interventions targeting FGF2 signaling to modulate the polarization of M1 and M2 macrophages in the management of sepsis-induced acute lung injury.

Exosomes (EXOs) are important mediators of intercellular communication that contain a variety of substances, including miRNA, mRNA, DNA, and protein molecules, which can act on target cells and have broad medical prospects as “cell-free therapy”. The inclusion of EXOs varies with the type and state of the donor cell, thus EXOs from different cell types may exhibit different biological effects. Dental mesenchymal stem cell (DMSC)-derived EXOs (DMSC-EXOs) have gained increasing research attention in the fields of tissue regenerative medicine and immune regulation. Current research on EXOs is focused on the homeostasis between proinflammatory (M1)/anti-inflammatory (M2) macrophages and T-helper 17 (Th17)/regulatory T (Treg) cells during periodontal immune regulation. Studies have shown that DMSC-EXOs can promote the transformation of macrophages and T cells and that this function may be dependent on the surrounding microenvironment and the tissue origin of stem cells. For instance, miR-1246 in dental pulp stem cell-derived EXOs promotes M2 macrophage polarization by inhibiting nuclear factor kappa-B (NF-κB) p65. Meanwhile, EXOs derived from stem cells from apical papilla promote DNA demethylase Tet2-mediated demethylation of FoxP3, maintain stable FoxP3 expression, and promote Treg cell transformation, thus alleviating local inflammation in periodontitis. In addition, the immunomodulatory activities of DMSC-EXOs can be affected by inflammatory factors. For example, EXOs derived from lipopolysaccharide-preconditioned dental follicle stem cells can reduce the receptor activator of NF-κB ligand/osteoprotegerin ratio through the reactive oxygen species (ROS)/c-Jun N-terminal kinase signaling pathway and promote M2 macrophage polarization through the ROS/extracellular signal-regulated kinase signaling pathway. Additionally, EXOs derived from gingiva-derived mesenchymal stem cells pretreated with tumor necrosis factor-α and interferon-α proinflammatory cytokines can promote M2 macrophage polarization through high expression of CD73 and CD5L, while EXOs derived from inflammatory periodontal ligament stem cells can promote M1 macrophage polarization. This article reviews the research progress on the immunoregulation and effects of DMSC-EXOs on the homeostasis of M1/M2 macrophages and Th17/Treg cells during periodontal immune regulation and provides a reference for the treatment of periodontitis using DMSC-EXOs.

Abstract In the tumor microenvironment, macrophages play crucial roles resulting in tumor suppression and progression, depending on M1 and M2 macrophages, respectively. In particular, macrophage-derived exosomes modulate the gene expression of cancer cells by delivering miRNAs which downregulate specific genes. The communication between macrophages and cancer cells is especially important in immunogenic tumors such as melanoma, where the cancer pogression is significantly influenced by the surrounding immune cells. In this study, we identified that M1 macrophages secrete exosomal miR-29c-3p in the co-culture system with melanoma cells. Simultaneously, ENPP2, the target of miR-29c-3p, decreased in the melanoma cells which are co-cultured with M1 macrophages. Additionally, we observed that the reduction of ENPP2 alleviates melanoma cell migration and invasion, due to the changes of cholesterol metabolism and ECM remodeling. Based on these findings, we demonstrated that M1 macrophages suppress aggressiveness of melanoma cells via exosomal miR-29c-3p-mediated knock-down of ENPP2 in cancer cells. Graphical Abstract

Background: The expression and function of coexpression genes of M1 macrophage in cervical cancer have not been identified. And the CXCL9-expressing tumour-associated macrophage has been poorly reported in cervical cancer. Methods: To clarify the regulatory gene network of M1 macrophage in cervical cancer, we downloaded gene expression profiles of cervical cancer patients in TCGA database to identify M1 macrophage coexpression genes. Then we constructed the protein-protein interaction networks by STRING database and performed functional enrichment analysis to investigate the biological effects of the coexpression genes. Next, we used multiple bioinformatics databases and experiments to overall investigate coexpression gene CXCL9, including western blot assay and immunohistochemistry assay, GeneMANIA, Kaplan-Meier Plotter, Xenashiny, TISCH2, ACLBI, HPA, TISIDB, GSCA and cBioPortal databases. Results: There were 77 positive coexpression genes and 5 negative coexpression genes in M1 macrophage. The coexpression genes in Ml macrophage participated in the production and function of chemokines and chemokine receptors. Especially, CXCL9 was positively correlated with M1 macrophage infiltration levels in cervical cancer. CXCL9 expression would significantly decrease and high CXCL9 levels were linked to good prognosis in the cervical cancer tumour patients, it manifestly expressed in blood immune cells, and was positively related to immune checkpoints. CXCL9 amplification was the most common type of mutation. The CXCL9 gene interaction network could regulate immune-related signalling pathways, and CXCL9 amplification was the most common mutation type in cervical cancer. Meanwhile, CXCL9 may had clinical significance for the drug response in cervical cancer, possibly mediating resistance to chemotherapy and targeted drug therapy. Conclusion: Our findings may provide new insight into the Ml macrophage coexpression gene network and molecular mechanisms in cervical cancer, and indicated that Ml macrophage association gene CXCL9 may serve as a good prognostic gene and a potential therapeutic target for cervical cancer therapies. [ABSTRACT FROM AUTHOR]

Abstract Background M1 macrophages are closely associated with cardiac injury after myocardial infarction (MI). Increasing evidence shows that exosomes play a key role in pathophysiological regulation after MI, but the role of M1 macrophage-derived exosomes (M1-Exos) in myocardial regeneration remains unclear. In this study, we explored the impact of M1 macrophage-derived exosomes on cardiomyocytes regeneration in vitro and in vivo. Methods M0 macrophages were induced to differentiate into M1 macrophages with GM-CSF (50 ng/mL) and IFN-γ (20 ng/mL). Then M1-Exos were isolated and co-incubated with cardiomyocytes. Cardiomyocyte proliferation was detected by pH3 or ki67 staining. Quantitative real-time PCR (qPCR) was used to test the level of miR-155 in macrophages, macrophage-derived exosomes and exosome-treated cardiomyocytes. MI model was constructed and LV-miR-155 was injected around the infarct area, the proliferation of cardiomyocytes was counted by pH3 or ki67 staining. The downstream gene and pathway of miR-155 were predicted and verified by dual-luciferase reporter gene assay, qPCR and immunoblotting analysis. IL-6 (50 ng/mL) was added to cardiomyocytes transfected with miR-155 mimics, and the proliferation of cardiomyocytes was calculated by immunofluorescence. The protein expressions of IL-6R, p-JAK2 and p-STAT3 were detected by Western blot. Results The results showed that M1-Exos suppressed cardiomyocytes proliferation. Meanwhile, miR-155 was highly expressed in M1-Exos and transferred to cardiomyocytes. miR-155 inhibited the proliferation of cardiomyocytes and antagonized the pro-proliferation effect of interleukin 6 (IL-6). Furthermore, miR-155 targeted gene IL-6 receptor (IL-6R) and inhibited the Janus kinase 2(JAK)/Signal transducer and activator of transcription (STAT3) signaling pathway. Conclusion M1-Exos inhibited cardiomyocyte proliferation by delivering miR-155 and inhibiting the IL-6R/JAK/STAT3 signaling pathway. This study provided new insight and potential treatment strategy for the regulation of myocardial regeneration and cardiac repair by macrophages.

Korean mistletoe (Viscum album L. var. coloratum) is renowned for its medicinal properties, including anti-cancer and immunoadjuvant effects. This study aimed to elucidate the mechanisms by which Korean mistletoe lectin (V. album L. var. coloratum agglutinin; VCA) modulates breast cancer cell apoptosis and macrophage polarization. The specific objectives were to (1) investigate the direct effects of VCA on MCF-7 breast cancer cells and THP-1-derived M1/M2 macrophages; (2) analyze the impact of VCA on the paracrine interactions between these cell types; and (3) compare the efficacy of VCA in 2D vs. 3D co-culture models to bridge the gap between in vitro and in vivo studies. We employed both 2D and 3D models, co-culturing human M1/M2 macrophages with human MCF-7 breast cancer cells in a Transwell system. Our research demonstrated that M1 and M2 macrophages significantly influenced the immune and apoptotic responses of breast cancer cells when exposed to VCA. M1 macrophages exhibited cytotoxic characteristics and enhanced VCA-induced apoptosis in both 2D and 3D co-culture models. Conversely, M2 macrophages initially displayed a protective effect by reducing apoptosis in breast cancer cells, but this protective effect was reversed upon exposure to VCA. Furthermore, our findings illustrate VCA's ability to modulate M1 and M2 polarization in breast cancer cells. Finally, the use of magnetic 3D cell cultures suggests their potential to yield results comparable to conventional 2D cultures, bridging the gap between in vitro and in vivo studies. [ABSTRACT FROM AUTHOR]

Objective To explore the effect and mechanism of berberine combined with curcumin on atherosclerosis (AS) by mediating M1 macrophages polarization. Methods M1-type macrophages were obtained from mouse mononuclear macrophages (RAW264.7) induced by lipopolysaccharide (LPS, 100 ng/mL) and interferon (IFN)-γ (20 ng/mL). A cell model was established. The cells were divided into a control group, model group, berberine group, curcumin group and berberine plus curcumin group. Concentrations of berberine and curcumin were detected by CCK-8 assay. The expression levels of M1-type macrophage markers iNOS, TNF-α, CXCL9 and p-STAT6/STAT6 in macrophage supernatant were detected by ELISA. Levels of iNOS, TNF-α and CXCL9 mRNA were detected by RT-PCR. Levels of iNOS, STAT6 and p-STAT6 proteins in each group were detected by Western blot. After down-regulation of STAT6 level by siRNA technology, expression of p-STAT6 protein was detected by Western blot. Expression levels of iNOS, TNF-α, CXCL9 and p-STAT6 were detected by ELISA. Results In the polarization of M1 macrophages induced by LPS and IFN-γ, berberine (25 μmol/L) and curcumin (20 μmol/L) were the best concentrations as compared with other drug concentration groups, and neither alone nor combined use could significantly inhibit the viability of RAW264.7 cells (P < 0.05). As compared with the normal group, iNOS, TNF-α and CXCL9 mRNA and protein levels were increased in the model group, while P-STAT6/STAT6 levels were decreased, with statistical differences (P < 0.05). As compared with the model group, iNOS, TNF-α and CXCL9 mRNA and protein levels in the berberine group, curcumin group, and berberine plus curcumin group were decreased, while P-STAT6 /STAT6 levels were increased, and the changes were more obvious in berberine plus curcumin group, with statistical difference (P < 0.05). After transfection of STAT6 siRNA in M1 macrophages in the berberine plus curcumin group, P-STAT6 levels were down-regulated, while expressions of iNOS, TNF-α and CXCL9 were up-regulated, with statistical differences (P < 0.05). Conclusions Both berberine and curcumin can inhibit the activity of M1-type macrophages and reduce inflammatory response. The action of berberine combined with curcumin is more advantageous than that of either drug alone, which may be the main mechanism of action through activation of STAT6. [ABSTRACT FROM AUTHOR]

Background: M1 macrophages are closely associated with cardiac injury after myocardial infarction (MI). Increasing evidence shows that exosomes play a key role in pathophysiological regulation after MI, but the role of M1 macrophage-derived exosomes (M1-Exos) in myocardial regeneration remains unclear. In this study, we explored the impact of M1 macrophage-derived exosomes on cardiomyocytes regeneration in vitro and in vivo. Methods: M0 macrophages were induced to differentiate into M1 macrophages with GM-CSF (50 ng/mL) and IFN-γ (20 ng/mL). Then M1-Exos were isolated and co-incubated with cardiomyocytes. Cardiomyocyte proliferation was detected by pH3 or ki67 staining. Quantitative real-time PCR (qPCR) was used to test the level of miR-155 in macrophages, macrophage-derived exosomes and exosome-treated cardiomyocytes. MI model was constructed and LV-miR-155 was injected around the infarct area, the proliferation of cardiomyocytes was counted by pH3 or ki67 staining. The downstream gene and pathway of miR-155 were predicted and verified by dual-luciferase reporter gene assay, qPCR and immunoblotting analysis. IL-6 (50 ng/mL) was added to cardiomyocytes transfected with miR-155 mimics, and the proliferation of cardiomyocytes was calculated by immunofluorescence. The protein expressions of IL-6R, p-JAK2 and p-STAT3 were detected by Western blot. Results: The results showed that M1-Exos suppressed cardiomyocytes proliferation. Meanwhile, miR-155 was highly expressed in M1-Exos and transferred to cardiomyocytes. miR-155 inhibited the proliferation of cardiomyocytes and antagonized the pro-proliferation effect of interleukin 6 (IL-6). Furthermore, miR-155 targeted gene IL-6 receptor (IL-6R) and inhibited the Janus kinase 2(JAK)/Signal transducer and activator of transcription (STAT3) signaling pathway. Conclusion: M1-Exos inhibited cardiomyocyte proliferation by delivering miR-155 and inhibiting the IL-6R/JAK/STAT3 signaling pathway. This study provided new insight and potential treatment strategy for the regulation of myocardial regeneration and cardiac repair by macrophages. [ABSTRACT FROM AUTHOR]

Liver fibrosis is characterized by chronic inflammatory responses and progressive fibrous scar formation. Macrophages play a central role in the pathogenesis of hepatic fibrosis by reconstructing the immune microenvironment. Picroside II (PIC II), extracted from Picrorhizae Rhizoma, has demonstrated therapeutic potential for various liver damage. However, the mechanisms by which macrophage polarization initiates immune cascades and contributes to the development of liver fibrosis, and whether this process can be influenced by PIC II, remain unclear. In the current study, RNA sequencing and multiple molecular approaches were utilized to explore the underlying mechanisms of PIC II against liver fibrosis in multidrug-resistance protein 2 knockout (Mdr2−/−) mice. Our findings indicate that PIC II activates M1-polarized macrophages to recruit natural killer cells (NK cells), potentially via the CXCL16-CXCR6 axis. Additionally, PIC II promotes the apoptosis of activated hepatic stellate cells (aHSCs) and enhances the cytotoxic effects of NK cells, while also reducing the formation of neutrophil extracellular traps (NETs). Notably, the anti-hepatic fibrosis effects associated with PIC II were largely reversed by macrophage depletion in Mdr2−/− mice. Collectively, our research suggests that PIC II is a potential candidate for halting the progression of liver fibrosis. [ABSTRACT FROM AUTHOR]

Peroxidation of polyunsaturated fatty acids results in the creation of numerous α, β‐unsaturated aldehydes, many of which are complicated by the development of diabetes. Trans, trans‐2,4‐decadienal (DDE) is a dietary α, β‐unsaturated aldehyde that is commonly found in food and the environment. However, it is unknown whether DDE exposure has some negative effects on glucose homeostasis and insulin sensitivity. This study investigated the biological effects of long‐term DDE exposure in normal chow diet (NCD)‐fed non‐obese mice and high‐fat diet (HFD)‐fed obese mice. Results showed that oral administration of DDE for 14 weeks did not cause severe toxicity in NCD‐fed non‐obese mice but had significant adverse effects in HFD‐fed obese mice. It was found that DDE exposure caused significant increases in LDL and ALT levels and aggravated glucose intolerance and insulin resistance in obese mice. Moreover, DDE robustly accumulated in adipose tissue and promoted the impairment of the insulin signaling pathway in the adipose tissue of obese mice while not affecting the skeletal muscle or liver. Mechanistically, DDE aggravated adipose tissue inflammation by promoting M1 macrophage accumulation and increasing proinflammatory cytokines in the adipocytes of obese mice, thus leading to impaired systemic insulin resistance. These findings provide crucial insights into the potential health impacts of long‐term DDE exposure. [ABSTRACT FROM AUTHOR]

SeviL, a galactoside-binding lectin previously isolated from the mussel Mytilisepta virgata, was demonstrated to trigger apoptosis in HeLa ovarian cancer cells. Here, we show that this lectin can promote the polarization of macrophage cell lines toward an M1 functional phenotype at low concentrations. The administration of SeviL to monocyte and basophil cell lines reduced their growth in a dose-dependent manner. However, low lectin concentrations induced proliferation in the RAW264.7 macrophage cell line, which was supported by the significant up-regulation of TOM22, a component of the mitochondrial outer membrane. Furthermore, the morphology of lectin-treated macrophage cells markedly changed, shifting from a spherical to an elongated shape. The ability of SeviL to induce the polarization of RAW264.7 cells to M1 macrophages at low concentrations is supported by the secretion of proinflammatory cytokines and chemokines, as well as by the enhancement in the expression of IL-6- and TNF-α-encoding mRNAs, both of which encode inflammatory molecular markers. Moreover, we also observed a number of accessory molecular alterations, such as the activation of MAP kinases and the JAK/STAT pathway and the phosphorylation of platelet-derived growth factor receptor-α, which altogether support the functional reprogramming of RAW264.7 following SeviL treatment. These results indicate that this mussel β-trefoil lectin has a concentration-dependent multifunctional role in regulating cell proliferation, phenotype, and death in macrophages, suggesting its possible involvement in regulating hemocyte activity in vivo. [ABSTRACT FROM AUTHOR]

Abstract Not all patients can benefit from chemotherapy due to the various of tumor type, stage, location, and the different distribution of immune cells in tumor immune microenvironment (TIME). Immune cells are widely involved in every step of cancer progression, including immune escape, metastasis, drug response, and prognosis. In this study, we explored the transcriptome data of 10 solid tumors treated with chemotherapy to identify the role of immune cells. We downloaded the transcriptome and mutation data of 10 cancers from TCGA databases, and used ESTIMATE and CIBERSORT algorithms to assess the proportion of immune cells in the TIME. According to the proportion of specific immune cell infiltration (SICI) of CD8+ T cells and M1 macrophages to group the patients, we found that compared with the SICI low and medium groups, the SICI high group had a larger tumor mutation burden, more gene mutations with targeted drugs, more activation of immune checkpoints (PD‐1, PD‐L1, CTLA‐4, LAG‐3, TIM‐3, and TIGIT), and immune molecules (CD8a, CD80, CD86, TLR2, HLA‐A, HLA‐B, and CD11a) (p

Abstract Background Extracellular vesicles (EVs) derived from human adipose-derived mesenchymal stem cells (hADSCs) have shown great therapeutic potential in plastic and reconstructive surgery. However, the limited production and functional molecule loading of EVs hinder their clinical translation. Traditional two-dimensional culture of hADSCs results in stemness loss and cellular senescence, which is unfavorable for the production and functional molecule loading of EVs. Recent advances in regenerative medicine advocate for the use of three-dimensional culture of hADSCs to produce EVs, as it more accurately simulates their physiological state. Moreover, the successful application of EVs in tissue engineering relies on the targeted delivery of EVs to cells within biomaterial scaffolds. Methods and Results The hADSCs spheroids and hADSCs gelatin methacrylate (GelMA) microspheres are utilized to produce three-dimensional cultured EVs, corresponding to hADSCs spheroids-EVs and hADSCs microspheres-EVs respectively. hADSCs spheroids-EVs demonstrate excellent production and functional molecule loading compared with hADSCs microspheres-EVs. The upregulation of eight miRNAs (i.e. hsa-miR-486-5p, hsa-miR-423-5p, hsa-miR-92a-3p, hsa-miR-122-5p, hsa-miR-223-3p, hsa-miR-320a, hsa-miR-126-3p, and hsa-miR-25-3p) and the downregulation of hsa-miR-146b-5p within hADSCs spheroids-EVs show the potential of improving the fate of remaining ear chondrocytes and promoting cartilage formation probably through integrated regulatory mechanisms. Additionally, a quick and innovative pipeline is developed for isolating chondrocyte homing peptide-modified EVs (CHP-EVs) from three-dimensional dynamic cultures of hADSCs spheroids. CHP-EVs are produced by genetically fusing a CHP at the N-terminus of the exosomal surface protein LAMP2B. The CHP + LAMP2B-transfected hADSCs spheroids were cultured with wave motion to promote the secretion of CHP-EVs. A harvesting method is used to enable the time-dependent collection of CHP-EVs. The pipeline is easy to set up and quick to use for the isolation of CHP-EVs. Compared with nontagged EVs, CHP-EVs penetrate the biomaterial scaffolds and specifically deliver the therapeutic miRNAs to the remaining ear chondrocytes. Functionally, CHP-EVs show a major effect on promoting cell proliferation, reducing cell apoptosis and enhancing cartilage formation in remaining ear chondrocytes in the M1 macrophage-infiltrated microenvironment. Conclusions In summary, an innovative pipeline is developed to obtain CHP-EVs from three-dimensional dynamic culture of hADSCs spheroids. This pipeline can be customized to increase EVs production and functional molecule loading, which meets the requirements for regulating remaining ear chondrocyte fate in the M1 macrophage-infiltrated microenvironment. Graphical Abstract

Macrophages have strong plasticity and heterogeneity, and can undergo functional transformation in response to different signal stimuli, such as classical activation of M1 type (M1 type polarization) and selective activation of M2 type (M2 type polarization). The pathways of macrophage M1/M2 polarization are quite extensive, involving nuclear factor-κB (NF-κB)/mitogen-activated protein kinase (MAPK) signaling pathway, interleukin-4 (IL-4)/signal transduction and activator of transcription 6 (STAT6) signaling pathway, Notch signaling pathway, Wnt/β-catenin signaling pathway, etc. At the same time, M1/M2 polarization of macrophages is also regulated by exosomes, metabolites, non-coding RNA, electrical stimulation, probiotics, etc., and its imbalance is closely related to the occurrence and development of different types of liver disease. In this paper, the mechanism of its polarization was reviewed, and it was found that M1 polarization of macrophages played a promoting role in the process of liver tissue injury, inflammation and fibrosis, while M2 polarization of macrophages played the opposite role. Among them, hepatocellular carcinoma, as the advanced stage of chronic liver disease, was characterized by increased M2 polarization and impaired M1 polarization of macrophages. Therefore, this paper pays attention to the role of M1/M2 polarization of macrophages in different types of liver diseases, in order to better establish the targeted therapy of macrophage subsets.

Abstract CD74 is a type-II transmembrane glycoprotein that has been linked to tumorigenesis. However, this association was based only on phenotypic studies, and, to date, no in-depth mechanistic studies have been conducted. In this study, combined with a multi-omics study, CD74 levels were significantly upregulated in most cancers relative to normal tissues and were found to be predictive of prognosis. Elevated CD74 expression was associated with reduced levels of mismatch-repair genes and homologous repair gene signatures in over 10 tumor types. Multiple fluorescence staining and bulk, spatial, single-cell transcriptional analyses indicated its potential as a marker for M1 macrophage infiltration in pan-cancer. In addition, CD74 expression was higher in BRCA patients responsive to conventional chemotherapy and was able to predict the prognosis of these patients. Potential CD74-activating drugs (HNHA and BRD-K55186349) were identified through molecular docking to CD74. The findings indicate activation of CD74 may have potential in tumor immunotherapy.

Abstract Background The combination of radiotherapy and immunotherapy (immunoradiotherapy) has been increasingly used for treating a wide range of cancers. However, some tumors are resistant to immunoradiotherapy. We have previously shown that MER proto-oncogene tyrosine kinase (MerTK) expressed on macrophages mediates resistance to immunoradiotherapy. We therefore sought to develop therapeutics that can mitigate the negative impact of MerTK. We designed and developed a MerTK specific antisense oligonucleotide (ASO) and characterized its effects on eliciting an anti-tumor immune response in mice. Methods 344SQR cells were injected into the right legs on day 0 and the left legs on day 4 of 8-12 weeks old female 129sv/ev mice to establish primary and secondary tumors, respectively. Radiation at a dose of 12 Gy was given to the primary tumors on days 8, 9, and 10. Mice received either anti-PD-1, anti-CTLA-4 or/and MerTK ASO starting from day 1 post tumor implantation. The composition of the tumor microenvironment and the level of MerTK on macrophages in the tumor were evaluted by flow cytometry. The expression of immune-related genes was investigated with NanoString. Lastly, the impact of MerTK ASO on the structure of the eye was histologically evaluated. Results Remarkably, the addition of MerTK ASO to XRT+anti-PD1 and XRT+anti-CTLA4 profoundly slowed the growth of both primary and secondary tumors and significantly extended survival. The ASO significantly reduced the expression of MerTK in tumor-associated macrophages (TAMs), reprograming their phenotype from M2 to M1. In addition, MerTK ASO increased the percentage of Granzyme B+ CD8+ T cells in the secondary tumors when combined with XRT+anti-CTLA4. NanoString results demonstrated that the MerTK ASO favorably modulated immune-related genes for promoting antitumor immune response in secondary tumors. Importantly, histological analysis of eye tissues demonstrated that unlike small molecules, the MerTK ASO did not produce any detectable pathology in the eyes. Conclusions The MerTK ASO can significantly downregulate the expression of MerTK on TAMs, thereby promoting antitumor immune response. The combination of MerTK ASO with immunoradiotherapy can safely and significantly slow tumor growth and improve survival. Graphical Abstract

Background The intestinal-liver axis is associated with various liver diseases. Here, we verified the role of the gut microbiota and macrophage activation in the progression of pyrrolizidine alkaloids-induced hepatic sinusoidal obstruction syndrome (PA-HSOS), and explored the possible mechanisms and new treatment options.Methods The HSOS murine model was induced by gavage of monocrotaline (MCT). An analysis of 16S ribosomal DNA (16S rDNA) of the feces was conducted to determine the composition of the fecal microbiota. Macrophage clearance, fecal microbiota transplantation (FMT), and butyrate supplementation experiments were used to assess the role of intestinal flora, gut barrier, and macrophage activation and to explore the relationships among these three variables.Results Activated macrophages and low microflora diversity were observed in HSOS patients and murine models. Depletion of macrophages attenuated inflammatory reactions and apoptosis in the mouse liver. Moreover, compared with control-FMT mice, the exacerbation of severe liver injury was detected in HSOS-FMT mice. Specifically, butyrate fecal concentrations were significantly reduced in HSOS mice, and administration of butyrate could partially alleviated liver damage and improved the intestinal barrier in vitro and in vivo. Furthermore, elevated lipopolysaccharides in the portal vein and high proportions of M1 macrophages in the liver were also detected in HSOS-FMT mice and mice without butyrate treatment, which resulted in severe inflammatory responses and further accelerated HSOS progression.Conclusions These results suggested that the gut microbiota exacerbated HSOS progression by regulating macrophage M1 polarization via altered intestinal barrier function mediated by butyrate. Our study has identified new strategies for the clinical treatment of HSOS.

The immune mechanism underlying hepatitis B surface antigen (HBsAg) loss, particularly type I inflammatory response, during pegylated interferon‐α (PEG‐IFN) therapy remains unclear. In this study, we aimed to elucidate such immune mechanisms. Overall, 82 patients with chronic hepatitis B (CHB), including 41 with HBsAg loss (cured group) and 41 uncured patients, received nucleos(t)ide analogue and PEG‐IFN treatments. Blood samples from all patients, liver tissues from 14 patients with CHB, and hepatic perfusate from 8 liver donors were collected for immune analysis. Jurkat, THP‐1 and HepG2.2.15 cell lines were used in cell experiments. The proportion of IFN‐γ+ Th1 cells was higher in the cured group than in the uncured group, which was linearly correlated with HBsAg decline and alanine aminotransferase (ALT) levels during treatment. However, CD8+ T cells were weakly associated with HBsAg loss. Serum and intrahepatic levels of Th1 cell‐associated chemokines (C‐X‐C motif chemokine ligand [CXCL] 9, CXCL10, CXCL11, IFN‐γ) were significantly lower in the cured patients than in patients with a higher HBsAg quantification during therapy. Serum from cured patients induced more M1 (CD68+CD86+ macrophage) cells than that from uncured patients. Patients with chronic HBV infection had significantly lower proportions of CD86+ M1 and CD206+ M2 macrophages in their livers than healthy controls. M1 polarization of intrahepatic Kupffer cells promoted HBsAg loss by upregulating the effector function of tissue‐resident memory T cells with increased ALT levels. IFN‐γ+ Th1 activates intrahepatic resident memory T cells to promote HBsAg loss by inducing M1 macrophage polarization. [ABSTRACT FROM AUTHOR]

CD74 is a type-II transmembrane glycoprotein that has been linked to tumorigenesis. However, this association was based only on phenotypic studies, and, to date, no in-depth mechanistic studies have been conducted. In this study, combined with a multi-omics study, CD74 levels were significantly upregulated in most cancers relative to normal tissues and were found to be predictive of prognosis. Elevated CD74 expression was associated with reduced levels of mismatch-repair genes and homologous repair gene signatures in over 10 tumor types. Multiple fluorescence staining and bulk, spatial, single-cell transcriptional analyses indicated its potential as a marker for M1 macrophage infiltration in pan-cancer. In addition, CD74 expression was higher in BRCA patients responsive to conventional chemotherapy and was able to predict the prognosis of these patients. Potential CD74-activating drugs (HNHA and BRD-K55186349) were identified through molecular docking to CD74. The findings indicate activation of CD74 may have potential in tumor immunotherapy. [ABSTRACT FROM AUTHOR]

Acute aortic dissection (AAD) progresses rapidly and is associated with high mortality; therefore, there remains an urgent need for pharmacological agents that can protect against AAD. Herein, we examined the therapeutic effects of cannabidiol (CBD) in AAD by establishing a suitable mouse model. In addition, we performed human AAD single-cell RNA sequencing and mouse AAD bulk RNA sequencing to elucidate the potential underlying mechanism of CBD. Pathological assays and in vitro studies were performed to verify the results of the bioinformatic analysis and explore the pharmacological function of CBD. In a β-aminopropionitrile (BAPN)-induced AAD mouse model, CBD reduced AAD-associated morbidity and mortality, alleviated abnormal enlargement of the ascending aorta and aortic arch, and suppressed macrophage infiltration and vascular smooth muscle cell (VSMC) apoptosis. Bioinformatic analysis revealed that the pro-apoptotic gene PMAIP1 was highly expressed in human and mouse AAD samples, and CBD could inhibit Pmaip1 expression in AAD mice. Using human aortic VSMCs (HAVSMCs) co-cultured with M1 macrophages, we revealed that CBD alleviated HAVSMCs mitochondrial-dependent apoptosis by suppressing the BAPN-induced overexpression of PMAIP1 in M1 macrophages. PMAIP1 potentially mediates HAVSMCs apoptosis by regulating Bax and Bcl2 expression. Accordingly, CBD reduced AAD-associated morbidity and mortality and mitigated the progression of AAD in a mouse model. The CBD-induced effects were potentially mediated by suppressing macrophage infiltration and PMAIP1 (primarily expressed in macrophages)-induced VSMC apoptosis. Our findings offer novel insights into M1 macrophages and HAVSMCs interaction during AAD progression, highlighting the potential of CBD as a therapeutic candidate for AAD treatment. (A) CBD can potentially decrease AAD-associated morbidity and mortality and mitigate the progression of AAD in a mouse model. (B) Patients with AAD exhibit increased expression of PMAIP1 in aortic tissues. (C) Analysis of human AAD single-cell RNA-seq data reveals that PMAIP1 is predominantly expressed in macrophages. (D) CBD may protect against mitochondrial-dependent apoptosis of HAVSMCs during AAD progression by inhibiting PMAIP1 expression in M1 macrophages. AA, ascending aorta; Arch, aortic arch; AAD, acute aortic dissection; BAPN, β-aminopropionitrile; CBD, cannabidiol; EC, endothelial cell; FB, fibroblast; HAVSMCs, human aortic vascular smooth muscle cells; MP, macrophage; SMC, smooth muscle cell; T, T lymphocytes. [Display omitted] • CBD reduced AAD-associated mortality and mitigated AAD progression. • CBD suppressed macrophage infiltration and vascular smooth muscle cell apoptosis. • PMAIP1 induced vascular smooth muscle cell mitochondria-dependent apoptosis. • CBD inhibited PMAIP1 expression in M1 macrophages. • CBD is a potential pharmacological candidate for AAD treatment. [ABSTRACT FROM AUTHOR]

Macrophages have strong plasticity and heterogeneity, and can undergo functional transformation in response to different signal stimuli, such as classical activation of M1 type (M1 type polarization) and selective activation of M2 type (M2 type polarization). The pathways of macrophage M1/M2 polarization are quite extensive, involving nuclear factor-κB (NF-κB)/mitogenactivated protein kinase (MAPK) signaling pathway, interleukin-4 (IL-4)/signal transduction and activator of transcription 6 (STAT6) signaling pathway, Notch signaling pathway, Wnt/β-catenin signaling pathway, etc. At the same time, M1/M2 polarization of macrophages is also regulated by exosomes, metabolites, non-coding RNA, electrical stimulation, probiotics, etc., and its imbalance is closely related to the occurrence and development of different types of liver disease. In this paper, the mechanism of its polarization was reviewed, and it was found that M1 polarization of macrophages played a promoting role in the process of liver tissue injury, inflammation and fibrosis, while M2 polarization of macrophages played the opposite role. Among them, hepatocellular carcinoma, as the advanced stage of chronic liver disease, was characterized by increased M2 polarization and impaired M1 polarization of macrophages. Therefore, this paper pays attention to the role of M1/M2 polarization of macrophages in different types of liver diseases, in order to better establish the targeted therapy of macrophage subsets. [ABSTRACT FROM AUTHOR]

Ulcerative colitis (UC) is an idiopathic chronic intestinal inflammation. An increasing body of evidence shows that macrophages play an important role in the pathogenesis of UC. Interferon regulatory factor 4 (IRF4) is crucial for the development of autoimmune diseases via regulating immune cells. This research was designed to explore the function of IRF4 in UC and its association with macrophage polarization. The in vitro model of UC was established by stimulating colonic epithelial cells with tumor necrosis factor α (TNF‐α). A mouse model of UC was constructed by injecting C57BL/6 mice with dextran sulfate sodium salt. Flow cytometry was used to assess percentage of CD11b+CD86+ and CD11b+CD206+ cells in bone marrow macrophages. Occult blood tests were used to detect hematochezia. Hematoxylin and eosin staining assay was used to assess colon pathological changes. Enzyme‐linked immunosorbent assay (ELISA) was used to detect concentrations of inflammatory cytokines. The interaction of IRF4 and B‐cell lymphoma 6 (Bcl6) was confirmed using GST pull‐down and coimmunoprecipitation assays. Our findings revealed that IRF4 promoted cell apoptosis and stimulated M1 macrophage polarization in vitro. Furthermore, IRF4 aggravated symptoms of the mouse model of UC and aggravated M1 macrophage polarization in vivo. IRF4 negatively regulated Bcl6 expression. Downregulation of Bcl6 promoted apoptosis and M1 macrophage polarization in the presence of IRF4 in vitro and in vivo. Moreover, Bcl6 positively mediated the Janus kinase 2 (JAK2)/signal transducer and activator of transcription 3 (STAT3) signaling pathway. In conclusion, IRF4 aggravated UC progression through promoting M1 macrophage polarization via Bcl6/JAK2/STAT3 pathway. These findings suggested that IRF4 might be a good target to competitively inhibit or to treat with UC. [ABSTRACT FROM AUTHOR]

Background: The combination of radiotherapy and immunotherapy (immunoradiotherapy) has been increasingly used for treating a wide range of cancers. However, some tumors are resistant to immunoradiotherapy. We have previously shown that MER proto-oncogene tyrosine kinase (MerTK) expressed on macrophages mediates resistance to immunoradiotherapy. We therefore sought to develop therapeutics that can mitigate the negative impact of MerTK. We designed and developed a MerTK specific antisense oligonucleotide (ASO) and characterized its effects on eliciting an anti-tumor immune response in mice. Methods: 344SQR cells were injected into the right legs on day 0 and the left legs on day 4 of 8-12 weeks old female 129sv/ev mice to establish primary and secondary tumors, respectively. Radiation at a dose of 12 Gy was given to the primary tumors on days 8, 9, and 10. Mice received either anti-PD-1, anti-CTLA-4 or/and MerTK ASO starting from day 1 post tumor implantation. The composition of the tumor microenvironment and the level of MerTK on macrophages in the tumor were evaluted by flow cytometry. The expression of immune-related genes was investigated with NanoString. Lastly, the impact of MerTK ASO on the structure of the eye was histologically evaluated. Results: Remarkably, the addition of MerTK ASO to XRT+anti-PD1 and XRT+anti-CTLA4 profoundly slowed the growth of both primary and secondary tumors and significantly extended survival. The ASO significantly reduced the expression of MerTK in tumor-associated macrophages (TAMs), reprograming their phenotype from M2 to M1. In addition, MerTK ASO increased the percentage of Granzyme B+ CD8+ T cells in the secondary tumors when combined with XRT+anti-CTLA4. NanoString results demonstrated that the MerTK ASO favorably modulated immune-related genes for promoting antitumor immune response in secondary tumors. Importantly, histological analysis of eye tissues demonstrated that unlike small molecules, the MerTK ASO did not produce any detectable pathology in the eyes. Conclusions: The MerTK ASO can significantly downregulate the expression of MerTK on TAMs, thereby promoting antitumor immune response. The combination of MerTK ASO with immunoradiotherapy can safely and significantly slow tumor growth and improve survival. [ABSTRACT FROM AUTHOR]

Lymphatic vessels have been increasingly appreciated in the context of immunology not only as passive conduits for immune and cancer cell transport but also as key in local tissue immunomodulation. Targeting lymphatic vessel growth and potential immune regulation often takes advantage of vascular endothelial growth factor receptor-3 (VEGFR-3) signaling to manipulate lymphatic biology. A receptor tyrosine kinase, VEGFR- 3, is highly expressed on lymphatic endothelial cells, and its signaling is key in lymphatic growth, development, and survival and, as a result, often considered to be "lymphatic-specific" in adults. A subset of immune cells, notably of the monocyte-derived lineage, have been identified to express VEGFR-3 in tissues from the lung to the gut and in conditions as varied as cancer and chronic kidney disease. These VEGFR-3+ macrophages are highly chemotactic toward the VEGFR-3 ligands VEGF-C and VEGF-D. VEGFR-3 signaling has also been implicated in dictating the plasticity of these cells from pro-inflammatory to anti-inflammatory phenotypes. Conversely, expression may potentially be transient during monocyte differentiation with unknown effects. Macrophages play critically important and varied roles in the onset and resolution of inflammation, tissue remodeling, and vasculogenesis: targeting lymphatic vessel growth and immunomodulation by manipulating VEGFR-3 signaling may thus impact macrophage biology and their impact on disease pathogenesis. This mini review highlights the studies and pathologies in which VEGFR-3+ macrophages have been specifically identified,aswellastheactivityand polarization changes that macrophage VEGFR-3 signaling may elicit, and affords some conclusions as to the importance of macrophage VEGFR-3 signaling in disease. [ABSTRACT FROM AUTHOR]

Osteoporosis, which manifests as reduced bone mass and deteriorated bone quality, is common in the elderly population. It is characterized by persistent elevation of macrophage-associated inflammation and active osteoclast bone resorption. Currently, the roles of intracellular metabolism in regulating these processes remain unclear. In this study, we initially performed bioinformatics analysis and observed a significant increase in the proportion of M1 macrophages in bone marrow with aging. Further metabolomics analysis demonstrated a notable reduction in the expression of carnitine metabolites in aged macrophages, while carnitine was not detected in osteoclasts. During the differentiation process, osteoclasts took up carnitine synthesized by macrophages to regulate their own activity. Mechanistically, carnitine enhanced the function of Nrf2 by inhibiting the Keap1-Nrf2 interaction, reducing the proteasome-dependent ubiquitination and degradation of Nrf2. In silico molecular ligand docking analysis of the interaction between carnitine and Keap1 showed that carnitine binds to Keap1 to stabilize Nrf2 and enhance its function. In this study, we found that the decrease in carnitine levels in aging macrophages causes overactivation of osteoclasts, ultimately leading to osteoporosis. A decrease in serum carnitine levels in patients with osteoporosis was found to have good diagnostic and predictive value. Moreover, supplementation with carnitine was shown to be effective in the treatment of osteoporosis. Carnitine activates Nrf2 in macrophage by inhibiting Keap1-Nrf2 protein-protein interaction (PPI), which further exerts anti-osteoporosis effects. In addition, carnitine serves a diagnostic indicator for osteoporosis. [Display omitted] [ABSTRACT FROM AUTHOR]

The exact function of M1 macrophages and CXCL9 in forecasting the effectiveness of immune checkpoint inhibitors (ICIs) is still not thoroughly investigated. We investigated the potential of M1 macrophage and C‐X‐C Motif Chemokine Ligand 9 (CXCL9) as predictive markers for ICI efficacy, employing a comprehensive approach integrating multicohort analysis and single‐cell RNA sequencing. A significant correlation between high M1 macrophage and improved overall survival (OS) and objective response rate (ORR) was found. M1 macrophage expression was most pronounced in the immune‐inflamed phenotype, aligning with increased expression of immune checkpoints. Furthermore, CXCL9 was identified as a key marker gene that positively correlated with M1 macrophage and response to ICIs, while also exhibiting associations with immune‐related pathways and immune cell infiltration. Additionally, through exploring RNA epigenetic modifications, we identified Apolipoprotein B MRNA Editing Enzyme Catalytic Subunit 3G (APOBEC3G) as linked to ICI response, with high expression correlating with improved OS and immune‐related pathways. Moreover, a novel model based on M1 macrophage, CXCL9, and APOBEC3G‐related genes was developed using multi‐level attention graph neural network, which showed promising predictive ability for ORR. This study illuminates the pivotal contributions of M1 macrophages and CXCL9 in shaping an immune‐active microenvironment, correlating with enhanced ICI efficacy. The combination of M1 macrophage, CXCL9, and APOBEC3G provides a novel model for predicting clinical outcomes of ICI therapy, facilitating personalized immunotherapy. [ABSTRACT FROM AUTHOR]

Scope: Ribes fasciculatum Siebold & Zucc. var. chinense Maxim. Leave extract (RFE) has been reported to be non-toxic and suitable for consumption as a food, with documented anti-allergic and anti-obesity effects. Skeletal muscle atrophy in various chronic inflammatory conditions has been a significant concern, yet the role of RFE in ameliorating muscle atrophy remains to be demonstrated. This study aims to investigate the regulation of muscle atrophy by RFE in chronic inflammatory conditions. Methods and results: C2C12 myoblasts were treated with conditioned medium from Raw264.7 macrophages induced with LPS to simulate an inflammatory condition, or with conditioned medium containing RFE. This study found that muscle atrophy is significantly exacerbated in the inflammatory conditions, while RFE markedly improves this condition. RFE was found to recover the diminished differentiation capacity of myoblasts that occurs in chronic inflammatory conditions. Importantly, RFE mediates inhibition of polarization into pro-inflammatory M1 macrophages in Raw264.7 cells. This indicates that afzelin, active compound of RFE, interferes with the binding of LPS to the TLR4/MD2 complex. Conclusion: These results suggest that RFE can improve muscle atrophy in chronic inflammatory states by disrupting the binding of LPS to the TLR4/MD2 complex and inhibiting the polarization of macrophages into M1 phenotype.

Brucellosis is a global zoonotic infection caused by Brucella bacteria, which poses a significant burden on society. While transmission prevention is currently the most effective method, the absence of a licenced vaccine for humans necessitates the urgent development of a safe and effective vaccine. Recombinant protein-based subunit vaccines are considered promising options, and in this study, the Brucella BP26 protein is expressed using prokaryotic expression systems. The immune responses are evaluated using the well-established adjuvant CpG-ODN. The results demonstrate that rBP26 supplemented with a CpG adjuvant induces M1 macrophage polarization and stimulates cellular immune responses mediated by Th1 cells and CD8+ T cells. Additionally, it generates high levels of rBP26-specific antibodies in immunized mice. Furthermore, rBP26 immunization activates, proliferates, and produces cytokines in T lymphocytes while also maintaining immune memory for an extended period of time. These findings shed light on the potential biological function of rBP26, which is crucial for understanding brucellosis pathogenesis. Moreover, rBP26 holds promise as an effective subunit vaccine candidate for use in endemic areas.

Patients diagnosed with non-small cell lung cancer (NSCLC) have a limited lifespan and exhibit poor immunotherapy outcomes. M1 macrophages have been found to be essential for antitumor immunity. This study aims to develop an immunotherapy response evaluation model for NSCLC patients based on transcription. RNA sequencing profiles of 254 advanced-stage NSCLC patients treated with immunotherapy are downloaded from the POPLAR and OAK projects. Immune cell infiltration in NSCLC patients is examined, and thereafter, different coexpressed genes are identified. Next, the impact of M1 macrophage-related genes on the prognosis of NSCLC patients is investigated. Six M1 macrophage coexpressed genes, namely, NKX2-1, CD8A , SFTA3, IL2RB, IDO1, and CXCL9, exhibit a strong association with the prognosis of NSCLC and serve as effective predictors for immunotherapy response. A response model is constructed using a Cox regression model and Lasso Cox regression analysis. The M1 genes are validated in our TD-FOREKNOW NSCLC clinical trial by RT-qPCR. The response model shows excellent immunotherapy response prediction and prognosis evaluation value in advanced-stage NSCLC. This model can effectively predict advanced NSCLC prognosis and aid in identifying patients who could benefit from customized immunotherapy as well as sensitive drugs.

Macrophages are critical components of the immune system and play vital roles in pathogen defense, immune regulation, and tissue repair. These cells exhibit different polarization states depending on environmental signals, and the M1/M2 paradigm is a useful tool for comprehending these states. This review article comprehensively presents the underlying mechanisms of M1 and M2 macrophage polarization and examines their polarization in various skin diseases. Additionally, this paper discusses therapeutic strategies that target M1 and M2 macrophage polarization in skin diseases. A more profound understanding of macrophage polarization in skin diseases could provide valuable insights for the development of innovative therapeutic strategies. [ABSTRACT FROM AUTHOR]

Background: Obesity is an inducible factor for the cause of chronic diseases and is described by an increase in the size and number of adipocytes that differentiate from precursor cells (preadipocytes). Parasitic helminths are the strongest natural trigger of type 2 immune system, and several studies have showed that helminth infections are inversely correlated with metabolic syndromes. Methodology/Principal findings: To investigate whether helminth-derived molecules have therapeutic effects on high-fat diet (HFD)-induced obesity, we isolated total lysates from Trichinella spiralis muscle larvae. We then checked the anti-obesity effect after intraperitoneal administration and intraoral administration of total lysate from T. spiralis muscle larvae in a diet-induced obesity model. T. spiralis total lysates protect against obesity by inhibiting the proinflammatory response and/or enhancing M2 macrophages. In addition, we determined the effects of total lysates from T. spiralis muscle larvae on anti-obesity activities in 3T3-L1 preadipocytes by investigating the expression levels of key adipogenic regulators, including peroxisome proliferator-activated receptor gamma (PPARγ), CCAAT-enhancer-binding protein alpha (C/EBPa) and adipocyte protein 2 (aP2). Oil Red O staining showed that the total lysates from T. spiralis muscle larvae decreased the differentiation of 3T3-L1 preadipocytes by decreasing the number of lipid droplets. In addition, the production levels of proinflammatory cytokines IL-1β, IL-6, IFN-γ and TNF-α were examined by enzyme-linked immunosorbent assay (ELISA). T. spiralis total lysates decreased intracellular lipid accumulation and suppressed the expression levels of PPARγ, C/EBPα and aP2. Conclusion/Significance: These results show that T. spiralis total lysate significantly suppresses the symptoms of obesity in a diet- induced obesity model and 3T3-L1 cell differentiation and suggest that it has potential for novel anti-obesity therapeutics. [ABSTRACT FROM AUTHOR]

Macrophages display extreme plasticity, and the mechanisms and applications of polarization and de-/repolarization of macrophages have been extensively investigated. However, the regulation of macrophage hysteresis after de-/repolarization remains unclear. In this study, by using a large-scale computational analysis of macrophage multi-omics data, we report a list of hysteresis genes that maintain their expression patterns after polarization and de-/repolarization. While the polarization in M1 macrophages leads to a higher level of hysteresis in genes associated with cell cycle progression, cell migration, and enhancement of the immune response, we found weak levels of hysteresis after M2 polarization. During the polarization process from M0 to M1 and back to M0, the factors IRFs/STAT, AP-1, and CTCF regulate hysteresis by altering their binding sites to the chromatin. Overall, our results show that a history of polarization can lead to hysteresis in gene expression and chromatin accessibility over a given period. This study contributes to the understanding of de-/repolarization memory in macrophages. [ABSTRACT FROM AUTHOR]

Research in tumor treatment has shown promising results using extracellular vesicles (EVs) derived from immune cells. EVs derived from M1 macrophages (proinflammatory), known as M1-EVs, have properties that suppress tumor growth, making them a promising treatment tool for immune susceptible tumors such as melanoma. Here, small unaltered M1-EVs (M1-sEVs) were employed in a 3D mouse melanoma model (melanospheres) to evaluate such activity. Macrophages were polarized and EVs were isolated by ultracentrifugation. The EVs obtained were characterized based on size, with measurements performed by dynamic light scattering and electron microscopy, and the expression profiles of microRNAs were analyzed by microarray and PCR. Melanospheres were used to evaluate the cytotoxicity of M1-sEVs. Pondering a possible future transposition from the animal model to the human, human melanoma cells were transfected with a specific miRNA, and the impact on cell proliferation was evaluated. The isolated EVs showed a size distribution between 50–400 nm in diameter, but preeminently in a range of 70–90 nm. M1-sEVs demonstrated a remarkable ability to reduce cell proliferation and viability in the melanospheres, leading to a decrease in their volume. M1-sEVs contained unique miRNAs, including miR-29a-3p, which exhibited significant antitumor activities according to bioinformatics analysis. Validation of the antitumor effects of miR-29a-3p was obtained by a functional evaluation, i.e., by inducing miRNA overexpression in human melanoma cells (SK-MEL-28). Although further research would be advisable, the study provides evidence supporting the potential of M1-sEVs and their miRNA load as a possible targeted immune therapy for melanoma. [ABSTRACT FROM AUTHOR]

Background: Tumor-associated macrophages (TAMs) are an important subset of innate immune cells in the tumor microenvironment, and they are pivotal regulators of tumor-promoting inflammation and tumor progression. Evidence has proven that TAM numbers are substantially increased in cancers, and most of these TAMs are polarized toward the alternatively activated M2 phenotype; Thus, these TAMs strongly promote the progression of cancer diseases. Type 1 innate lymphocytes (ILC1s) are present in high numbers in intestinal tissues and are characterized by the expression of the transcription factor T-bet and the secretion of interferon (IFN)-γ, which can promote macrophages to polarize toward the classically activated antitumor M1 phenotype. However, the relationship between these two cell subsets in colon cancer remains unclear. Methods: Flow cytometry was used to determine the percentages of M1-like macrophages, M2-like macrophages and ILC1s in colon cancer tissues and paracancerous healthy colon tissues in the AOM/DSS-induced mouse model of colon cancer. Furthermore, ILC1s were isolated and bone marrow-derived macrophages were generated to analyze the crosstalk that occurred between these cells when cocultured in vitro. Moreover, ILC1s were adoptively transferred or inhibited in vivo to explore the effects of ILC1s on tumor-infiltrating macrophages and tumor growth. Results: We found that the percentages of M1-like macrophages and ILC1s were decreased in colon cancer tissues, and these populations were positively correlated. ILC1s promoted the polarization of macrophages toward the classically activated M1-like phenotype in vitro, and this effect could be blocked by an anti-IFN-γ antibody. The in vivo results showed that the administration of the Group 1 innate lymphocyte-blocking anti-NK1.1 antibody decreased the number of M1-like macrophages in the tumor tissues of MC38 tumor-bearing mice and promoted tumor growth, and adoptive transfer of ILC1s inhibited tumors and increased the percentage of M1-like macrophages in MC38 tumor-bearing mice. Conclusions: Our studies preliminarily prove for the first time that ILC1s promote the activation of M1-like macrophages by secreting IFN-γ and inhibit the progression of colon cancer, which may provide insight into immunotherapeutic approaches for colon cancer. [ABSTRACT FROM AUTHOR]

The non-neuronal and non-muscular effects of botulinum toxin type A (BTXA) on scar reduction has been discovered. This study was designed to investigate the effects of BTXA on macrophages polarization during the early stage of skin repair. A skin defect model was established on the dorsal skin of SD rats. BTXA was intracutaneous injected into the edge of wound immediately as the model was established. Histological examinations were performed on scar samples. Raw 264.7 was selected as the cell model of recruited circulating macrophages, and was induced for M1 polarization by LPS. Identify the signaling pathways that primarily regulated M1 polarization and respond to BTXA treatment. Application of BTXA at early stage of injury significantly reduced the scar diameter without delaying wound closure. BTXA treatment improved fiber proliferation and arrangement, and inhibited angiogenesis in scar granular tissue. The number of M1 macrophages and the levels of pro-inflammation were decreased after treated with BTXA in scar tissues. LPS activated JAK2/STAT1 and IκB/NFκB pathways were downregulated by BTXA, as well as LPS induced M1 polarization. At early stage of skin wound healing, injection of BTXA effectively reduced the number of M1 macrophages and the levels of pro-inflammatory mediators which contributes to scar alleviation. BTXA resisted the M1 polarization of macrophages induced by LPS via deactivating the JAK2/STAT1 and IκB/NFκB pathways.

Abstract The exact function of M1 macrophages and CXCL9 in forecasting the effectiveness of immune checkpoint inhibitors (ICIs) is still not thoroughly investigated. We investigated the potential of M1 macrophage and C‐X‐C Motif Chemokine Ligand 9 (CXCL9) as predictive markers for ICI efficacy, employing a comprehensive approach integrating multicohort analysis and single‐cell RNA sequencing. A significant correlation between high M1 macrophage and improved overall survival (OS) and objective response rate (ORR) was found. M1 macrophage expression was most pronounced in the immune‐inflamed phenotype, aligning with increased expression of immune checkpoints. Furthermore, CXCL9 was identified as a key marker gene that positively correlated with M1 macrophage and response to ICIs, while also exhibiting associations with immune‐related pathways and immune cell infiltration. Additionally, through exploring RNA epigenetic modifications, we identified Apolipoprotein B MRNA Editing Enzyme Catalytic Subunit 3G (APOBEC3G) as linked to ICI response, with high expression correlating with improved OS and immune‐related pathways. Moreover, a novel model based on M1 macrophage, CXCL9, and APOBEC3G‐related genes was developed using multi‐level attention graph neural network, which showed promising predictive ability for ORR. This study illuminates the pivotal contributions of M1 macrophages and CXCL9 in shaping an immune‐active microenvironment, correlating with enhanced ICI efficacy. The combination of M1 macrophage, CXCL9, and APOBEC3G provides a novel model for predicting clinical outcomes of ICI therapy, facilitating personalized immunotherapy.

Abstract Background Despite intensive developments of adoptive T cell and NK cell therapies, the efficacy against solid tumors remains elusive. Our study demonstrates that macrophage-based cell therapy could be a potent therapeutic option against solid tumors. Methods To this end, we determine the effect of a natural triterpene glycoside, cucumarioside A2-2 (CA2-2), on the polarization of mouse macrophages into the M1 phenotype, and explore the antitumor activity of the polarized macrophage. The polarization of CA2-2-pretreated macrophages was analyzed by flow cytometry and confocal imaging. The anti-cancer activity of CA2-2 macrophages was evaluated against 4T1 breast cancer cells and EAC cells in vitro and syngeneic mouse model in vivo. Results Incubation of murine macrophages with CA2-2 led to polarization into the M1 phenotype, and the CA2-2-pretreated macrophages could selectively target and kill various types of cancer in vitro. Notably, loading near-infrared (NIR) fluorochrome-labeled nanoparticles, MnMEIO-mPEG-CyTE777, into macrophages substantiated that M1 macrophages can target and penetrate tumor tissues in vivo efficiently. Conclusion In this study, CA2-2-polarized M1 macrophages significantly attenuated tumor growth and prolonged mice survival in the syngeneic mouse models. Therefore, ex vivo CA2-2 activation of mouse macrophages can serve as a useful model for subsequent antitumor cellular immunotherapy developments.

Abstract Background Tumor-associated macrophages (TAMs) are an important subset of innate immune cells in the tumor microenvironment, and they are pivotal regulators of tumor-promoting inflammation and tumor progression. Evidence has proven that TAM numbers are substantially increased in cancers, and most of these TAMs are polarized toward the alternatively activated M2 phenotype; Thus, these TAMs strongly promote the progression of cancer diseases. Type 1 innate lymphocytes (ILC1s) are present in high numbers in intestinal tissues and are characterized by the expression of the transcription factor T-bet and the secretion of interferon (IFN)-γ, which can promote macrophages to polarize toward the classically activated antitumor M1 phenotype. However, the relationship between these two cell subsets in colon cancer remains unclear. Methods Flow cytometry was used to determine the percentages of M1-like macrophages, M2-like macrophages and ILC1s in colon cancer tissues and paracancerous healthy colon tissues in the AOM/DSS-induced mouse model of colon cancer. Furthermore, ILC1s were isolated and bone marrow-derived macrophages were generated to analyze the crosstalk that occurred between these cells when cocultured in vitro. Moreover, ILC1s were adoptively transferred or inhibited in vivo to explore the effects of ILC1s on tumor-infiltrating macrophages and tumor growth. Results We found that the percentages of M1-like macrophages and ILC1s were decreased in colon cancer tissues, and these populations were positively correlated. ILC1s promoted the polarization of macrophages toward the classically activated M1-like phenotype in vitro, and this effect could be blocked by an anti-IFN-γ antibody. The in vivo results showed that the administration of the Group 1 innate lymphocyte-blocking anti-NK1.1 antibody decreased the number of M1-like macrophages in the tumor tissues of MC38 tumor-bearing mice and promoted tumor growth, and adoptive transfer of ILC1s inhibited tumors and increased the percentage of M1-like macrophages in MC38 tumor-bearing mice. Conclusions Our studies preliminarily prove for the first time that ILC1s promote the activation of M1-like macrophages by secreting IFN-γ and inhibit the progression of colon cancer, which may provide insight into immunotherapeutic approaches for colon cancer.

Tumor-associated macrophages (TAMs) are inflammatory cells that are important components of the tumor microenvironment. TAMs are functionally heterogeneous and divided into two main subpopulations with distinct and opposite functions: M1 and M2 macrophages. The secretory function of TAMs is essential for combating infections, regulating immune responses, and promoting tissue repair. Extracellular vesicles (EVs) are nanovesicles that are secreted by cells. They play a crucial role in mediating intercellular information transfer between cells. EVs can be secreted by almost all types of cells, and they contain proteins, microRNAs, mRNAs, and even long non-coding RNAs (lncRNAs) that have been retained from the parental cell through the process of biogenesis. EVs can influence the function and behavior of target cells by delivering their contents, thus reflecting, to some extent, the characteristics of their parental cells. Here, we provide an overview of the role of M1 macrophages and their EVs in cancer therapy by exploring the impact of M1 macrophage-derived EVs (M1-EVs) on tumors by transferring small microRNAs. Additionally, we discuss the potential of M1-EVs as drug carriers and the possibility of reprogramming M2 macrophages into M1 macrophages for disease treatment. We propose that M1-EVs play a crucial role in cancer therapy by transferring microRNAs and loading them with drugs. Reprogramming M2 macrophages into M1 macrophages holds great promise in the treatment of cancers.

Korean mistletoe (Viscum album L. var. coloratum) is renowned for its medicinal properties, including anti-cancer and immunoadjuvant effects. This study aimed to elucidate the mechanisms by which Korean mistletoe lectin (V. album L. var. coloratum agglutinin; VCA) modulates breast cancer cell apoptosis and macrophage polarization. The specific objectives were to (1) investigate the direct effects of VCA on MCF-7 breast cancer cells and THP-1-derived M1/M2 macrophages; (2) analyze the impact of VCA on the paracrine interactions between these cell types; and (3) compare the efficacy of VCA in 2D vs. 3D co-culture models to bridge the gap between in vitro and in vivo studies. We employed both 2D and 3D models, co-culturing human M1/M2 macrophages with human MCF-7 breast cancer cells in a Transwell system. Our research demonstrated that M1 and M2 macrophages significantly influenced the immune and apoptotic responses of breast cancer cells when exposed to VCA. M1 macrophages exhibited cytotoxic characteristics and enhanced VCA-induced apoptosis in both 2D and 3D co-culture models. Conversely, M2 macrophages initially displayed a protective effect by reducing apoptosis in breast cancer cells, but this protective effect was reversed upon exposure to VCA. Furthermore, our findings illustrate VCA’s ability to modulate M1 and M2 polarization in breast cancer cells. Finally, the use of magnetic 3D cell cultures suggests their potential to yield results comparable to conventional 2D cultures, bridging the gap between in vitro and in vivo studies.