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Oxygen and arginine availability, and the tonicity and acidity in the tissue, have a major impact on type 2 nitric oxide synthase (NOS2) activity in situ. Commensal microbiota of the skin is critical for the induction of protective immune responses to Leishmania , but it also contributes to tissue pathology, depending on the context. During both the acute and persistent phases of infection, Leishmania parasites retreat into hematopoietic as well as non-hematopoietic host cells that function as safe replicative niches. Leishmania is an intracellular protozoan transmitted by sand fly vectors; it causes cutaneous, mucocutaneous, or visceral disease. Its growth and survival are impeded by type 1 T helper cell responses, which entail interferon (IFN)-γ-mediated macrophage activation. Leishmania partially escapes this host defense by triggering immune cell and cytokine responses that favor parasite replication rather than killing. Novel methods for in situ analyses have revealed that the pathways of immune control and microbial evasion are strongly influenced by the tissue context, the micro milieu factors, and the metabolism at the site of infection, which we collectively term the 'immunomicrotope'. Understanding the components and the impact of the immunomicrotope will enable the development of novel strategies for the treatment of chronic leishmaniasis. Leishmania is an intracellular protozoan transmitted by sand fly vectors; it causes cutaneous, mucocutaneous, or visceral disease. Its growth and survival are impeded by type 1 T helper cell responses, which entail interferon (IFN)-γ-mediated macrophage activation. Leishmania partially escapes this host defense by triggering immune cell and cytokine responses that favor parasite replication rather than killing. Novel methods for in situ analyses have revealed that the pathways of immune control and microbial evasion are strongly influenced by the tissue context, the micro milieu factors, and metabolism at the site of infection, which we collectively term the 'immunomicrotope'. Understanding the components and the impact of the immunomicrotope will enable the development of novel strategies for the treatment of chronic leishmaniasis. [ABSTRACT FROM AUTHOR]

Soluble CD163 (sCD163) is a biomarker of macrophage activation, not previously investigated in the circulation of traumatized patients. A biobank of 398 adult trauma patients was analyzed. Patients with an Injury Severity Score (ISS) >8 served as trauma patients (n = 195) and those with ISS ≤ 8 as trauma controls (n = 203). Serum samples obtained upon admission, 15h and 72h after were analyzed for sCD163 using an in-house ELISA. Multiple linear regression was used to analyze the association between admission levels of sCD163 with, 1: overall trauma severity (ISS), and 2: severity of injury to specified organs using Abbreviated Injury Score (AIS) and Glasgow Coma Scale (GCS). The association between the peak level of sCD163 with 1-year all-cause mortality was analyzed by logistic regression analysis. Median admission levels of sCD163 were higher in trauma patients than trauma controls [2.32 (IQR 1.73 to 2.86) vs. 1.92 (IQR 1.41 to 2.51) mg/L, p < 0.01]. Worsening GCS score was associated with a 10.3% (95% CI: 17.0 to 3.1, p < 0.01) increase in sCD163. Increasing Head-AIS score was associated with a 5.1% (95% CI: −0.5 to 11.0, p = 0.07) increase in sCD163. The remaining AIS scores and ISS were not consistently associated with sCD163 admission levels. Each mg/L increase in sCD163 peak level had an odds ratio 1.34 (95%CI: 0.98 to 1.83), p = 0.06) after adjustment for age, sex, and GCS. Circulating sCD163 is increased in traumatized patients and associated with worsening GCS. Our findings suggest an association between circulating sCD163 levels with 1-year all-cause mortality. [ABSTRACT FROM AUTHOR]

Circular RNA (circRNA) is a type of single-stranded RNA that forms a covalently closed continuous loop, unlike linear RNA. The expression of circRNAs in mammals is often conserved across species and shows tissue and cell specificity. Some circRNA serve as gene regulators. However, the biological function of most circRNAs is unclear. CircRNA does not have 5′ or 3′ ends. The unique structure of circRNAs provides them with a much longer half-life and more resistance to RNase R than linear RNAs. Inflammatory lung responses occur in the pathogenesis and recovery of many lung diseases. Macrophages form the first line of host defense/innate immune responses and initiate/mediate lung inflammation. For example, in bacterial pneumonia, upon pro-inflammatory activation, they release early response cytokines/chemokines that recruit neutrophils, macrophages, and lymphocytes to sites of infection and clear pathogens. The functional effects and mechanisms by which circRNAs exert physiological or pathological roles in macrophage activation and lung inflammation remain poorly understood. In this article, we will review the current understanding and progress of circRNA biogenesis, regulation, secretion, and degradation. Furthermore, we will review the current reports on the role of circRNAs in macrophage activation and polarization, as well as in the process of inflammatory lung responses. [ABSTRACT FROM AUTHOR]

Macrophages play a key role in ozone-induced lung injury by regulating both the initiation and resolution of inflammation. These distinct activities are mediated by pro-inflammatory and anti-inflammatory/proresolution macrophages which sequentially accumulate in injured tissues. Macrophage activation is dependent, in part, on intracellular metabolism. Herein, we used RNA-sequencing (seq) to identify signaling pathways regulating macrophage immunometabolic activity following exposure of mice to ozone (0.8 ppm, 3 h) or air control. Analysis of lung macrophages using an Agilent Seahorse showed that inhalation of ozone increased macrophage glycolytic activity and oxidative phosphorylation at 24 and 72 h post-exposure. An increase in the percentage of macrophages in S phase of the cell cycle was observed 24 h post ozone. RNA-seq revealed significant enrichment of pathways involved in innate immune signaling and cytokine production among differentially expressed genes at both 24 and 72 h after ozone, whereas pathways involved in cell cycle regulation were upregulated at 24 h and intracellular metabolism at 72 h. An interaction network analysis identified tumor suppressor 53 (TP53), E2F family of transcription factors (E2Fs), cyclin-dependent kinase inhibitor 1A (CDKN1a/p21), and cyclin D1 (CCND1) as upstream regulators of cell cycle pathways at 24 h and TP53, nuclear receptor subfamily 4 group a member 1 (NR4A1/Nur77), and estrogen receptor alpha (ESR1/ERα) as central upstream regulators of mitochondrial respiration pathways at 72 h. To assess whether ERα regulates metabolic activity, we used ERα−/− mice. In both air and ozone-exposed mice, loss of ERα resulted in increases in glycolytic capacity and glycolytic reserve in lung macrophages with no effect on mitochondrial oxidative phosphorylation. Taken together, these results highlight the complex interaction between cell cycle, intracellular metabolism, and macrophage activation which may be important in the initiation and resolution of inflammation following ozone exposure. [ABSTRACT FROM AUTHOR]

Tanshinone I (Tan I) has been proven to exert an anti-inflammatory effect, but the complete mechanism remains unclear. In this study, Tan I was described to have no effect on Syk expression in resting or LPS-stimulated macrophages ex vivo , but dramatically suppressed Syk phosphorylation and CD80, CD86, and IL-1β expression of macrophages. The inflammatory activity of macrophages in ApoC3-transgenic (ApoC3TG) mice is upregulated by Syk activation. Tan I was determined to downregulate Syk phosphorylation and inflammatory activity of macrophages in ApoC3TG mice, both ex vivo and in vivo. Intraperitoneal injection of Tan I (4 mg/kg) effectively alleviated DSS-induced colitis in mice, accompanying with suppressing the activation of intestinal macrophages. Mechanistically, Tan I-treated macrophages exhibited a decrease in cytoplasmic ROS, NLRP3, GSDMD, and IL-1β, which suggested that the alternative pathway of inflammasome activation in macrophages was suppressed. The SPR assay demonstrated that Tan I bound to Syk protein with a dissociation constant (KD) of 2.473 × 10−6 M. When Syk expression was knocked down by its shRNA, the inhibitory effects of Tan I on macrophages were blocked. Collectively, Tanshinone I effectively alleviated DSS-induced colitis in mice by inhibiting Syk-stimulated inflammasome activation, hence suppressing the inflammatory activity of macrophages. • Tanshinone I inhibited p-Syk and limited the inflammatory activity of macrophages. • Tanshinone I effectively alleviated DSS-induced colitis in mice by limiting the activation of intestinal macrophages. • Tanshinone I-treated macrophages exhibited a decrease in alternative pathway of inflammasome activation. • Direct binding of Tanshinone Ⅰ to Syk was confirmed by the surface plasmon resonance assay. [ABSTRACT FROM AUTHOR]

Alternatively activated macrophage (M2) polarization can result in one of four subtypes based on cytokines and signaling pathways associated with macrophage activation: M2a, M2b, M2c, and M2d macrophages. The majority of M2 subtypes are anti-inflammatory and pro-angiogenic, secreting growth factors (VEGF, PDGF) and matrix metalloproteinases (MMP2, MMP9) which boost tumor growth, metastasis, and invasion. M2-polarized macrophages are associated with immune suppressor cells harboring Myeloid derived suppressor cells, Regulatory T cells (Tregs), Regulatory B cells as well as alternatively activated (N2) neutrophils. Treg cells selectively support the metabolic stability, mitochondrial integrity, and survival rate of M2-like TAMs in an indirect environment. Also, the contribution of Breg cells influences macrophage polarization towards the M2 direction. TAM is activated when TAN levels in the tumor microenvironment are insufficient or vice versa, suggesting that macrophage and its polarization are fine-tuned. Understanding the functions of immune suppressive cells, mediators, and signaling pathways involved with M2 polarization will allow us to identify potential strategies for targeting the TAM repolarization phenotype for innovative immunotherapy approaches. In this review, we have highlighted the critical factors for M2 macrophage polarization, differential cytokine/chemokine profiles of M1 and M2 macrophage subtypes, and other immune cells' impact on the polarization within the immunosuppressive niche. Highlights: M2 macrophages are targetable immune cells for immunotherapy strategies. M2 type macrophages are more heterogeneous populations than M1 macrophages. M2 polarization is influenced by Tregs, Bregs, MDSCs, and N2 neutrophils. [ABSTRACT FROM AUTHOR]

Background: Diabetes mellitus (DM) is known to inhibit skin self-renewal and hair follicle stem cell (HFSC) activation, which may be key in the formation of chronic diabetic wounds. This study aimed to investigate the reasons behind the suppression of HFSC activation in DM mice. Methods: Type 1 DM (T1DM) was induced in 6-week-old mice via streptozotocin, and hair follicle growth was subsequently monitored. RNA sequencing, bioinformatics analyses, qRT‒PCR, immunostaining, and cellular experiments were carried out to investigate the underlying mechanisms involved. Results: T1DM inhibited HFSC activation, which correlated with an increase in caspase-dependent programmed cell death. Additionally, T1DM triggered apoptosis and pyroptosis, predominantly in HFSCs and epidermal regions, with pyroptosis being more pronounced in the inner root sheath of hair follicles. Notably, significant cutaneous immune imbalances were observed, particularly in macrophages. Cellular experiments demonstrated that M1 macrophages inhibited HaCaT cell proliferation and induced cell death, whereas high-glucose environments alone did not have the same effect. Conclusion: T1DM inhibits HFSC activation via macrophage reprogramming-mediated caspase-dependent pyroptosis, and there is a significant regional characterization of cell death. Moreover, T1DM-induced programmed cell death in the skin may be more closely related to immune homeostasis imbalance than to hyperglycemia itself. These findings shed light on the pathogenesis of diabetic ulcers and provide a theoretical basis for the use of hair follicle grafts in wound repair. [ABSTRACT FROM AUTHOR]

Macrophages represent primary players of the innate immune system. Macrophage activation triggers several signaling pathways and is tightly associated with metabolic changes, which drive different immune subsets. Recent studies unveil the role of various metabolic enzymes in macrophage activation. Here, we show that malic enzyme 1 (ME1) is overexpressed in LPS-induced macrophages. Through chromatin immunoprecipitation, we demonstrate that ME1 transcriptional regulation is under control of NF-κB. Furthermore, ME1 activity is also increased in activated human PBMC-derived macrophages. Notably, ME1 gene silencing decreases nitric oxide as well as reactive oxygen species and prostaglandin E2 inflammatory mediators. Therefore, modulating ME1 provides a potential approach for immunometabolic regulation and in turn macrophage function. [ABSTRACT FROM AUTHOR]

CD74 is a transmembrane protein that functions as a specialized chaperone of HLA class II and CD74 in tumor cells was suggested to be involved in cell proliferation in several kinds of malignant tumors. CD74 is also known to be expressed in macrophages, therefore, we investigated the CD74 expression in clear cell renal cell carcinoma (ccRCC). Immunohistochemistry of CD74 indicated that CD74 was expressed not only in cancer cells but also macrophages. CD74 was detected in surface membrane and cytoplasm of cancer cells in 92 of 94 cases (98%) and of 87 of 94 cases (93%). CD74 was expressed both in cancer cells and TAMs in 86 of 94 cases (91%). In vitro studies using cancer cell lines and monocyte-derived macrophages stimulated by anti-CD74 antibodies showed that CD74 signal accelerated cancer cell proliferation and macrophage activation. However, macrophage activation via CD74 signal did not influence macrophage-mediated cancer cell growth. RNA-sequence of macrophages stimulated by anti-CD74 antibodies indicated that CD74 signal was associated to inflammatory responses in macrophages. In conclusion, we examined the expression and functional significance of CD74 in ccRCC using tissue specimens and cell culture studies. The function of CD74 was suggested to be different in cancer cells and in macrophages, and further studies are necessary to clarify the functional significance of CD74 in ccRCC. [ABSTRACT FROM AUTHOR]

Pain is the leading symptom for most individuals with osteoarthritis (OA), a complex condition marked by joint discomfort. Recently, the dynamic interplay between the nervous and immune systems has become a focal point for understanding pain regulation. Despite this, there is still a substantial gap in our comprehensive understanding of the neuroimmune interactions and their effects on pain in OA. This review examines the bidirectional influences between immune cells and nerves in OA progression. It explores current approaches that target neuroimmune pathways, including promoting M2 macrophage polarization and specific neuronal receptor targeting, for effective pain reduction. Translational potential statement: This review provides a comprehensive overview of the mechanisms underlying the interplay between the immune system and nervous system during the progression of OA, as well as their contributions to pain. Additionally, it compiles existing intervention strategies targeting neuroimmunity for the treatment of OA pain. This information offers valuable insights for researchers seeking to address the challenge of OA pain.

BMP15 is a conserved regulator of ovarian development and maintenance in vertebrates. In humans, premature ovarian insufficiency is caused by autoimmunity and genetic factors, including mutation of BMP15. The cellular mechanisms underlying ovarian failure caused by BMP15 mutation and immune contributions are not understood. Using zebrafish, we established a causal link between macrophage activation and ovarian failure, which, in zebrafish, causes sex reversal. We define a germline-soma signaling axis that activates macrophages and drives ovarian failure and female-to-male sex reversal. Germline loss of zebrafish Bmp15 impairs oogenesis and initiates this cascade. Single-cell RNA sequencing and genetic analyses implicate ovarian somatic cells that express conserved macrophage-activating ligands as mediators of ovarian failure and sex reversal. Genetic ablation of macrophages or elimination of Csf1Rb ligands, Il34 or Csf1a, delays or blocks premature oocyte loss and sex reversal. The axis identified here provides insight into the cells and pathways governing oocyte and ovary maintenance and potential therapeutic targets to preserve female fertility.

Personalized neoantigen therapy has shown long‐term and stable efficacy in specific patient populations. However, not all patients have sufficient levels of neoantigens for treatment. Although somatic mutations are commonly found in tumours, a significant portion of these mutations do not trigger an immune response. Patients with low mutation burdens continue to exhibit unresponsiveness to this treatment. We propose a design paradigm for neoantigen vaccines by utilizing the highly immunogenic unnatural amino acid p‐nitrophenylalanine (pNO2Phe) for sequence alteration of somatic mutations that failed to generate neoepitopes. This enhances the immunogenicity of the mutations and transforms it into a suitable candidate for immunotherapy. The nitrated altered epitope vaccines designed according to this paradigm is capable of activating circulating CD8+ T cells and inducing immune cross‐reactivity against autologous mutated epitopes in different MHC backgrounds (H‐2Kb, H‐2Kd, and human HLA‐A02:01), leading to the elimination of tumour cells carrying the mutation. After immunization with the altered epitopes, tumour growth was significantly inhibited. It is noteworthy that nitrated epitopes induce tumour‐infiltrating macrophages to differentiate into the M1 phenotype, surprisingly enhancing the MHC II molecule presenting pathway of macrophages. Nitrated epitope‐treated macrophages have the potential to cross‐activate CD4+ and CD8+ T cells, which may explain why pNO2Phe can enhance the immunogenicity of epitopes. Meanwhile, the immunosuppressive microenvironment of the tumour is altered due to the activation of macrophages. The nitrated neoantigen vaccine strategy enables the design of vaccines targeting non‐immunogenic tumour mutations, expanding the pool of potential peptides for personalized and shared novel antigen therapy. This approach provides treatment opportunities for patients previously ineligible for new antigen vaccine therapy. [ABSTRACT FROM AUTHOR]

Abstract Background The immunologic features of nontuberculous mycobacterial pulmonary disease (NTM-PD) are largely unclear. This study investigated the immunologic features of NTM-PD using digital spatial profiling techniques. Methods Lung tissues obtained from six patients with NTM-PD between January 1, 2006, and December 31, 2020, at Seoul National University Hospital were subjected to RNA sequencing. Cores from the peribronchial areas were stained with CD3, CD68, and DNASyto13, and gene expression at the whole-transcriptome level was quantified using PCR amplification and Illumina sequencing. Lung tissues from six patients with bronchiectasis collected during the same period were used as controls. The RNA sequencing results were validated using immunohistochemistry (IHC) in another cohort (30 patients with NTM-PD and 15 patients with bronchiectasis). Results NTM-PD exhibited distinct gene expression patterns in T cells and macrophages. Gene set enrichment analysis revealed that pathways related to antigen presentation and processing were upregulated in NTM-PD, particularly in macrophages. Macrophages were more prevalent and the expression of genes associated with the M1 phenotype (CD40 and CD80) was significantly elevated. Although macrophages were activated in the NTM-PD group T cell activity was unaltered. Notably, expression of the costimulatory molecule CD28 was decreased in NTM-PD. IHC analysis showed that T cells expressing Foxp3 or TIM-3, which facilitate the regulatory functions of T cells, were increased. Conclusions NTM-PD exhibits distinct immunologic signatures characterized by the activation of macrophages without T cell activation.

Abstract Some herbal extracts contain relatively high amounts of lipopolysaccharide (LPS). Because orally administered LPS activates innate immunity without inducing inflammation, it plays a role as an active ingredient in herbal extracts. However, the LPS content in herbal extracts remains extensively unevaluated. This study aimed to create a database of LPS content in herbal extracts; therefore, the LPS content of 414 herbal extracts was measured and the macrophage activation potential was evaluated. The LPS content of these hot water extracts was determined using the kinetic–turbidimetric method. The LPS concentration ranged from a few ng/g to hundreds of μg/g (Standard Escherichia coli LPS equivalent). Twelve samples had a high-LPS-content of > 100 μg/g, including seven samples from roots and three samples from leaves of the herbal extracts. These samples showed high phagocytosis and NO production capacity, and further investigation using polymyxin B, an LPS inhibitor, significantly inhibited macrophage activation. This study suggests that some herbal extracts contain sufficient LPS concentration to activate innate immunity. Therefore, a new approach to evaluate the efficacy of herbal extracts based on their LPS content was proposed. A database listing the LPS content of different herbal extracts is essential for this approach.

Abstract Background Extended contact with silica particles can lead to Silicosis, a chronic lung condition lacking established treatment protocols or clear mechanisms of development. The urgency for innovative treatments arises from the unavailability of effective treatment methodologies. The origin of silica-induced pulmonary fibrosis includes essential processes such as macrophage activation and the conversion of fibroblasts into myofibroblasts, with oxidative stress playing a pivotal role. Shionone (SHI), a triterpenoid extracted from the Aster tataricus plant, is recognized for its extensive health benefits. This study explores the capability of SHI to alleviate the effects of silica-induced lung fibrosis in mice. Methods This investigation explored the impact of SHI on lung inflammation and fibrosis at different stages (early and late) triggered by silica in mice, focusing specifically on the initial and more developed phases. It comprised an analysis of isolated peritoneal macrophages and fibroblasts extracted from mice to elucidate SHI's therapeutic potential and its underlying mechanism. The methodology employed encompassed quantitative PCR, immunofluorescence, flow cytometry, and western blotting to examine macrophage activity and their transition into myofibroblasts. The activation of the nuclear factor erythroid 2-related factor 2 (Nrf2) pathway by SHI was confirmed via immunofluorescence and western blot studies. SHI's antioxidative properties were evidenced by the measurement of reactive oxygen species (ROS) and mitochondrial ROS within both macrophages and fibroblasts, using 2′, 7′-dichlorodihydrofluorescein diacetate and MitoSOX, respectively. The relevance of SHI was further underscored by applying ML385 and Nrf2 siRNA to gauge its effectiveness. Results Starting SHI treatment early countered the harmful effects of lung inflammation and fibrosis caused by silica, while initiating SHI at a later phase decelerated the advancement of fibrosis. SHI's action was linked to the activation of the Nrf2 signaling pathway, a boost in antioxidant enzyme levels, and a decrease in oxidative stress and inflammation in macrophages affected by silica. Furthermore, SHI prevented the conversion of fibroblasts into myofibroblasts prompted by TGF-β, along with the resultant oxidative stress. The beneficial outcomes of SHI were negated when ML385 and Nrf2 siRNA were applied, highlighting the pivotal role of the Nrf2 pathway in SHI's efficacy. Conclusion SHI plays a significant role in stimulating the Nrf2 pathway, thereby defending against silica-induced oxidative stress and inflammatory reactions in macrophages, and inhibiting the conversion of fibroblasts to myofibroblasts due to TGF-β. This suggests that SHI is a viable option for treating lung inflammation and fibrosis in mice suffering from silicosis.

Macrophages play a pivotal role as host cells for Leishmania parasites, displaying a notable functional adaptability ranging from the proinflammatory, leishmanicidal M1 phenotype to the anti-inflammatory, parasite-permissive M2 phenotype. While macrophages can potentially eradicate amastigotes through appropriate activation, Leishmania employs diverse strategies to thwart this activation and redirect macrophages toward an M2 phenotype, facilitating its survival and replication. Additionally, a competition for iron between the two entities exits, as iron is vital for both and is also implicated in macrophage defensive oxidative mechanisms and modulation of their phenotype. This review explores the intricate interplay between macrophages, Leishmania, and iron. We focus the attention on the potential of iron oxide nanoparticles (IONPs) as a sort of immunotherapy to treat some leishmaniasis forms by reprogramming Leishmania-permissive M2 macrophages into antimicrobial M1 macrophages. Through the specific targeting of iron in macrophages, the use of IONPs emerges as a promising strategy to finely tune the parasite-host interaction, endowing macrophages with an augmented antimicrobial arsenal capable of efficiently eliminating these intrusive microbes. [ABSTRACT FROM AUTHOR]

Macrophages in the innate immune system play a vital role in various lung diseases such as asthma, chronic obstructive pulmonary disease (COPD), acute lung injury and pulmonary fibrosis. Macrophages involved in the process of immunity need to go through a process of activation, including changes in gene expression and cell metabolism. Epigenetic modifications are key factors of macrophage activation including DNA methylation, histone modification and non-coding RNA regulation. Understanding the role and mechanisms of epigenetic regulation of macrophage activation can provide insights into the function of macrophages in lung diseases and help identification of potential therapeutic targets. This review summarizes the latest progress in the epigenetic changes and regulation of macrophages in their development process and in normal physiological states, and the epigenetic regulation of macrophages in COPD as well as the influence of macrophage activation on COPD development. [ABSTRACT FROM AUTHOR]

Background: Excessive inflammation poses significant risks to human physical and mental health. Astilbe grandis, a traditional Miao medicine, is renowned for its anti-inflammatory properties. However, the specific anti-inflammatory effects and mechanisms of many compounds within this plant remain unclear. This study aims to investigate the anti-inflammatory effects and mechanisms of two characteristic oleanane triterpenoids, 3α-acetoxyolean-12-en-27-oic acid (1) and 3β-acetoxyolean-12-en-27-oic acid (2), isolated from Astilbe grandis, using lipopolysaccharide (LPS)-induced Macrophages. Methods: The anti-inflammatory effects and mechanisms of compounds 1 and 2 were investigated by establishing an LPS-induced inflammation model in RAW 264.7 cells and THP-1 cells. Nitric oxide (NO) levels were assessed using the Griess method. The concentrations of tumor necrosis factor-alpha (TNF-α), interleukin-6 (IL-6), and interleukin-1beta (IL-1β) were measured via enzymelinked immunosorbent assay (ELISA). The expression of cyclooxygenase-2 (COX-2) and inducible nitric oxide synthase (iNOS) was determined using western blotting and quantitative real-time PCR (qRT-PCR). Additionally, the phosphorylation level of p65 in nuclear factor-kappa B (NF-κB) was assessed through western blotting. The nuclear translocation of NF-κB p65 was assessed through immunofluorescence staining. Finally, the binding affinity of the compounds to NF-κB p65 target was validated through molecular docking. Results: Compounds 1 and 2 significantly inhibited the expression of NO, TNF-α, IL-6, IL-1β, COX-2, and iNOS in LPS-induced Macrophages. Mechanistically, they attenuated the activation of the NF-κB signaling pathway by downregulating the phosphorylation level and nuclear translocation of p65. Conclusion: This study elucidates the anti-inflammatory activities and potential mechanism of the characteristic oleanane triterpenoids with C-14 carboxyl group, compounds 1 and 2, in LPS-induced Macrophages by inhibiting the NF-κB signaling pathway for the first time. These findings suggest that these two compounds hold promise as potential candidates for anti-inflammatory interventions in the future. [ABSTRACT FROM AUTHOR]

Background: The Lin−Sca1+c-Kit+ (LSK) fraction of the bone marrow (BM) comprises multipotent hematopoietic stem cells (HSCs), which are vital to tissue homeostasis and vascular repair. While diabetes affects HSC homeostasis overall, the molecular signature of mRNA and miRNA transcriptomic under the conditions of long-standing type 2 diabetes (T2D;>6 months) remains unexplored. Methods: In this study, we assessed the transcriptomic signature of HSCs in db/db mice, a well-known and widely used model for T2D. LSK cells of db/db mice enriched using a cell sorter were subjected to paired-end mRNA and single-end miRNA seq library and sequenced on Illumina NovaSeq 6000. The mRNA sequence reads were mapped using STAR (Spliced Transcripts Alignment to a Reference), and the miRNA sequence reads were mapped to the designated reference genome using the Qiagen GeneGlobe RNA-seq Analysis Portal with default parameters for miRNA. Results: We uncovered 2076 out of 13,708 mRNAs and 35 out of 191 miRNAs that were expressed significantly in db/db animals; strikingly, previously unreported miRNAs (miR-3968 and miR-1971) were found to be downregulated in db/db mice. Furthermore, we observed a molecular shift in the transcriptome of HSCs of diabetes with an increase in pro-inflammatory cytokines (Il4, Tlr4, and Tnf11α) and a decrease in anti-inflammatory cytokine IL10. Pathway mapping demonstrated inflammation mediated by chemokine, cytokine, and angiogenesis as one of the top pathways with a significantly higher number of transcripts in db/db mice. These molecular changes were reflected in an overt defect in LSK mobility in the bone marrow. miRNA downstream target analysis unveils several mRNAs targeting leukocyte migration, microglia activation, phagosome formation, and macrophage activation signaling as their primary pathways, suggesting a shift to an inflammatory phenotype. Conclusion: Our findings highlight that chronic diabetes adversely alters HSCs' homeostasis at the transcriptional level, thus potentially contributing to the inflammatory phenotype of HSCs under long-term diabetes. We also believe that identifying HSCs-based biomarkers in miRNAs or mRNAs could serve as diagnostic markers and potential therapeutic targets for diabetes and associated vascular complications. [ABSTRACT FROM AUTHOR]

Background: The immunologic features of nontuberculous mycobacterial pulmonary disease (NTM-PD) are largely unclear. This study investigated the immunologic features of NTM-PD using digital spatial profiling techniques. Methods: Lung tissues obtained from six patients with NTM-PD between January 1, 2006, and December 31, 2020, at Seoul National University Hospital were subjected to RNA sequencing. Cores from the peribronchial areas were stained with CD3, CD68, and DNASyto13, and gene expression at the whole-transcriptome level was quantified using PCR amplification and Illumina sequencing. Lung tissues from six patients with bronchiectasis collected during the same period were used as controls. The RNA sequencing results were validated using immunohistochemistry (IHC) in another cohort (30 patients with NTM-PD and 15 patients with bronchiectasis). Results: NTM-PD exhibited distinct gene expression patterns in T cells and macrophages. Gene set enrichment analysis revealed that pathways related to antigen presentation and processing were upregulated in NTM-PD, particularly in macrophages. Macrophages were more prevalent and the expression of genes associated with the M1 phenotype (CD40 and CD80) was significantly elevated. Although macrophages were activated in the NTM-PD group T cell activity was unaltered. Notably, expression of the costimulatory molecule CD28 was decreased in NTM-PD. IHC analysis showed that T cells expressing Foxp3 or TIM-3, which facilitate the regulatory functions of T cells, were increased. Conclusions: NTM-PD exhibits distinct immunologic signatures characterized by the activation of macrophages without T cell activation. [ABSTRACT FROM AUTHOR]

Esophageal cancer is common worldwide, with ESCC being the most frequent tumor in East Asia. Tumor-associated macrophages are an important component of the ESCC microenvironment. SUMOylation is a post-translational modification of proteins, and SUMO-specific proteases (SENPs) play an important role in de-SUMOylation. In human patients, we discovered that the levels of SENP3 were upregulated in the tumor-associated macrophages. Furthermore, the loss of SENP3 enhanced the alternative activation of macrophages in the 4-NQO-induced ESCC mice model. This is the first study to identify SENP3-mediated macrophage polarization via the de-SUMOylation of interferon regulatory factor 4 (IRF4) at the K349 site. Alternative activation of macrophages increases the migration and invasion potential of ESCC cells and promotes their progression in vivo. Moreover, patients with relatively low SENP3 expression in macrophages exhibit higher primary PET SUVmax value and lymph node metastasis rates. In summary, this study revealed that SENP3-mediated IRF4 de-SUMOylation is crucial for the alternative activation of macrophages and influences the progression of ESCC. Highlights: • SENP3 expression is upregulated in macrophages in esophageal squamous cell carcinoma. • The absence of SENP3 in macrophages promotes the progression of esophageal squamous cell carcinoma both in patients and in the 4-NQO-induced ESCC mice model. • Loss of SENP3 promotes macrophages' alternative activation by attenuating the de-SUMOylation of IRF4 at the K349 site. • ESCC patients with relatively low SENP3 expression in macrophages had higher primary tumor SUVmax and lymph node metastasis rates. [ABSTRACT FROM AUTHOR]

Purpose: Exosomal microRNAs have been identified as important mediators of communication between tumor cells and macrophages in the microenvironment. miR-541-5p was reported to be involved in hepatocellular carcinoma progression, but its role in gastric cancer (GC) and in GC cell-macrophage crosstalk is unknown. Methods: Cell proliferation, migration and invasion were respectively assessed by CCK-8 assay, scratch and Transwell assays. RT-qPCR was used to detect the level of miR-541-5p, macrophage markers and DUSP3. The percentage of CD11b+CD206+ cell population was analyzed by flow cytometry. Western blotting was employed to evaluate DUSP3-JAK2/STAT3 pathway proteins and exosome markers. The interaction between miR-541-5p and DUSP3 was verified by luciferase assay. Results: The results showed that miR-541-5p was upregulated in GC tissues and cells, and stimulated GC cell growth, migration and invasion in vitro. GC cells induce M2 macrophage polarization by secreting the exosomal miR-541-5p. Exosomal miR-541-5p maintained JAK2/STAT3 pathway activation in macrophages by targeting negative regulation of DUSP3. Inhibiting miR-541-5p significantly limited tumor growth in vivo. Conclusion: In conclusion, miR-541-5p promotes GC cell progression. GC cells may induce macrophage M2 polarization through the exosomal miR-541-5p-mediated DUSP3/JAK2/STAT3 pathway. miR-541-5p may be a potential therapeutic target for GC. [ABSTRACT FROM AUTHOR]

Neural damage due to inflammatory activation of macrophages and microglia is a consequence of HIV infection that leads to cognitive dysfunction. The damage is due, in part, to the release of factors that impair neuronal function but the mechanisms that control their release are poorly understood. Previous studies have shown that mature nerve growth factor (NGF) binding to tropomyosin receptor kinase A (TrkA), and proNGF acting through the p75 neurotrophin receptor (p75NTR) differentially control the phenotype of macrophages in response to HIV. However, the mechanisms responsible for these actions are unclear. The current studies demonstrated that in human monocyte-derived macrophages, CCR5 tropic HIV virions interact with the CXCR4 receptor to promote a neurotoxic macrophage phenotype. TrkA cooperatively interacted with CXCR4 to promote quick and dynamic changes in CXCR4 phosphorylation and more stable downstream actin remodeling in the form of membrane ruffles. TrkA signaling also promoted increased moacrophage calcium spiking, and low neurotoxic activity. Disruption of these interactions by HIV led to an alternative podosome-bearing phenotype with minimal calcium signaling and enhanced toxicity. Neurotrophin receptors provide an independent yet cooperative pathway for modifying the actin cytoskeleton in response to chemokines and subsequent degenerative activity. The strong opposing effects of mature and proneurotrophins may provide the opportunity to develop novel therapies that regulate the phenotype of macrophages in the context of HIV infection and perhaps other degenerative diseases. [ABSTRACT FROM AUTHOR]

Background and Aims: Acute liver failure is a multisystem disorder with a high mortality and frequent need for emergency liver transplantation. Following massive innate immune system activation, soluble markers of macrophage activation are released during liver damage and their association with disease severity and prognosis requires exploration. Methods: Patients ALF from the United States Acute Liver Failure Study Group (USALFSG, n = 224) and King's College Hospital (n = 40) together with healthy controls (HC, n = 50) were recruited. Serum from early (Days 1–3) and late (>Day 3) time points were analysed for MAMs by enzyme‐linked immunosorbent assay correlated to markers of illness severity and 21‐day spontaneous survival. Surface expression phenotyping was performed via Flow Cytometry on CD14+ monocytes. Results: All MAMs serum concentrations were significantly higher in ALF compared to controls (p <.0001). sCD206 concentration was higher in early and late stages of the disease in patients with bacteraemia (p =.002) and infection in general (p =.006). In MELD‐adjusted multivariate modelling, sCD206 and sCD163 were independently associated with mortality. CD14+ monocyte expression of CD206 (p <.001) was higher in patients with ALF compared with controls and correlated with SOFA score (p =.018). sCD206 was independently validated as a predictor of infection in an external cohort. Conclusions: sCD206 is increased in serum of ALF patients with infections and poor outcome and is upregulated on CD14+ monocytes. Later measurements of sCD163 and sCD206 during the evolution of ALF have potential as mechanistic predictors of mortality. sCD206 should be explored as a biomarker of sepsis and mortality in ALF. [ABSTRACT FROM AUTHOR]

Foam cells in atheroma are engorged with lipid droplets (LDs) that contain esters of regulatory lipids whose metabolism remains poorly understood. LD-associated hydrolase (LDAH) has a lipase structure and high affinity for LDs of foam cells. Using knockout and transgenic mice of both sexes, here we show that LDAH inhibits atherosclerosis development and promotes stable lesion architectures. Broad and targeted lipidomic analyzes of primary macrophages and comparative lipid profiling of atheroma identified a broad impact of LDAH on esterified sterols, including natural liver X receptor (LXR) sterol ligands. Transcriptomic analyzes coupled with rescue experiments show that LDAH modulates the expression of prototypical LXR targets and leads macrophages to a less inflammatory phenotype with a profibrotic gene signature. These studies underscore the role of LDs as reservoirs and metabolic hubs of bioactive lipids, and suggest that LDAH favorably modulates macrophage activation and protects against atherosclerosis via lipolytic mobilization of regulatory sterols. The mechanisms and consequences of bioactive lipids release from lipid droplets remain poorly understood. Here the authors link a lipid droplet enzyme to mobilization of esters of regulatory sterols in foam cells and protection against atherosclerosis. [ABSTRACT FROM AUTHOR]

Cyclic-nucleotide phosphodiesterases (PDEs) represent a superfamily of enzymes playing a pivotal role in cell signaling by controlling cAMP and cGMP levels in response to receptor activation. PDE activity and expression are linked to many diseases including inflammatory diseases. In light of their specific biochemical properties, PDE inhibition has attracted the interest of several researrs In this context, PDE4 inhibition induces anti-inflammatory effects. Piclamilast and rolipram, well-known PDE4 inhibitors, are endowed with common side effects. The selective phosphodiesterase 4B (PDE4B) inhibitors could be a promising approach to overcome these side effects. In the present study, six potential PDE4B inhibitors have been investigated. Through this study, we identified three PDE4B inhibitors in human macrophages activated by lipopolysaccharide. Interestingly, two of them reduced reactive oxygen species production in pro-inflammatory macrophages. [ABSTRACT FROM AUTHOR]

Macrophage alternative activation is involved in kidney fibrosis. Previous researches have documented that the transcriptional regulators Yes‐associated protein (Yap)/transcriptional coactivator with PDZ‐binding motif (Taz) are linked to organ fibrosis. However, limited knowledge exists regarding the function and mechanisms of their downstream molecules in regulating macrophage activation and kidney fibrosis. In this paper, we observed that the Hippo pathway was suppressed in macrophages derived from fibrotic kidneys in mice. Knockout of Taz or Tead1 in macrophages inhibited the alternative activation of macrophages and reduced kidney fibrosis. Additionally, by using bone marrow–derived macrophages (BMDMs), we investigated that knockout of Taz or Tead1 in macrophages impeded both cell proliferation and migration. Moreover, deletion of Tead1 reduces p‐Smad3 and Smad3 abundance in macrophages. And chromatin immunoprecipitation (ChIP) assays showed that Tead1 could directly bind to the promoter region of Smad3. Collectively, these results indicate that Tead1 knockout in macrophages could reduce TGFβ1‐induced phosphorylation Smad3 via transcriptional downregulation of Smad3, thus suppressing macrophage alternative activation and IRI‐induced kidney fibrosis. [ABSTRACT FROM AUTHOR]

Background: Chronic obstructive pulmonary disease (COPD) remains a leading cause of morbidity and mortality worldwide, characterized by persistent respiratory symptoms and airflow limitation. The involvement of C–C motif chemokine ligand 2 (CCL2) in COPD pathogenesis, particularly in macrophage regulation and activation, is poorly understood despite its recognized role in chronic inflammation. Our study aims to elucidate the regulatory role and molecular mechanisms of CCL2 in the pathogenesis of COPD, providing new insights for therapeutic strategies. Methods: This study focused on the CCL2-CCR2 signaling pathway, exploring its role in COPD pathogenesis using both Ccl2 knockout (KO) mice and pharmacological inhibitors. To dissect the underlying mechanisms, we employed various in vitro and in vivo methods to analyze the secretion patterns and pathogenic effects of CCL2 and its downstream molecular signaling through the CCL2-CCR2 axis. Results: Elevated Ccl2 expression was confirmed in the lungs of COPD mice and was associated with enhanced recruitment and activation of macrophages. Deletion of Ccl2 in knockout mice, as well as treatment with a Ccr2 inhibitor, resulted in protection against CS- and LPS-induced alveolar injury and airway remodeling. Mechanistically, CCL2 was predominantly secreted by bronchial epithelial cells in a process dependent on STAT1 phosphorylation and acted through the CCR2 receptor on macrophages. This interaction activated the PI3K-AKT signaling pathway, which was pivotal for macrophage activation and the secretion of inflammatory cytokines, further influencing the progression of COPD. Conclusions: The study highlighted the crucial role of CCL2 in mediating inflammatory responses and remodeling in COPD. It enhanced our understanding of COPD's molecular mechanisms, particularly how CCL2's interaction with the CCR2 activates critical signaling pathways. Targeting the CCL2-CCR2 axis emerged as a promising strategy to alleviate COPD pathology. [ABSTRACT FROM AUTHOR]

Lactylation is a process where lactate, a cellular metabolism byproduct, is added to proteins, altering their functions. In the realm of macrophage activation, lactylation impacts inflammatory response and immune regulation. Understanding the effects of lactylation on macrophage activation is vital in lung diseases, as abnormal activation and function are pivotal in conditions like pneumonia, pulmonary fibrosis, COPD, and lung cancer. This review explores the concept of lactylation, its regulation of macrophage activation, and recent research progress in lung diseases. It offers new insights into lung disease pathogenesis and potential therapeutic targets. [ABSTRACT FROM AUTHOR]

Tumor-associated macrophages play a crucial role in the tumor microenvironment. Tripartite motif 59 (TRIM59), a member of the tripartite motif (TRIM) family, is known to be associated with immunological diseases and macrophage activation. The functional and molecular mechanisms by which TRIM59 affects the occurrence and development of colorectal cancer (CRC) through macrophages are still not well understood. To address this, we generated macrophage-specific TRIM59 conditional knockout mice and utilized these mice to establish colitis-associated cancer and MC38 transplanted CRC models for further investigation. We found that the deficiency of TRIM59 in macrophages inhibited colorectal tumorigenesis in mice. This tumor-suppressive effect was achieved by promoting the activation of M1 macrophages via STAT1 signaling pathway. Further mechanistic studies revealed that TRIM59 could regulate macrophage polarization by ubiquitinating and degrading STAT1. These findings provide evidence that TRIM59 deficiency promotes M1 macrophage activation and inhibits CRC through the STAT1 signaling pathway, suggesting that the TRIM59/STAT1 signaling pathway may be a promising target for CRC. [ABSTRACT FROM AUTHOR]

Tuberculosis (TB) remains a global public health threat. Understanding the dynamics of host-pathogen interactions within TB granulomas will assist in identifying what leads to the successful elimination of infection. In vitro TB models provide a controllable environment to study these granuloma dynamics. Previously we developed a biomimetic 3D spheroid granuloma model that controls bacteria better than a traditional monolayer culture counterpart. We used agent-based simulations to predict the mechanistic reason for this difference. Our calibrated simulations were able to predict heterogeneous bacterial dynamics that are consistent with experimental data. In one group of simulations, spheroids are found to have higher macrophage activation than their traditional counterparts, leading to better bacterial control. This higher macrophage activation in the spheroids was not due to higher counts of activated T cells, instead fewer activated T cells were able to activate more macrophages due to the proximity of these cells to each other within the spheroid. In a second group of simulations, spheroids again have more macrophage activation but also more T cell activation, specifically CD8+ T cells. This higher level of CD8+ T cell activation is predicted to be due to the proximity of these cells to the cells that activate them. Multiple mechanisms of control were predicted. Simulations removing individual mechanisms show that one group of simulations has a CD4+ T cell dominant response, while the other has a mixed/CD8+ T cell dominant response. Lastly, we demonstrated that in spheroids the initial structure and movement rules work synergistically to reduce bacterial load. These findings provide valuable insights into how the structural complexity of in vitro models impacts immune responses. Moreover, our study has implications for engineering more physiologically relevant in vitro models and advancing our understanding of TB pathogenesis and potential therapeutic interventions. Author summary: Tuberculosis (TB) is a respiratory infection that is associated with granulomas, organized clusters of immune cells that form around the bacteria. Recent work has focused on making in vitro models that better approximate these granulomas, such as our spheroid granuloma model. We found that this spheroid was better able to control bacteria than its traditional culture counterpart, so, in this work, we use agent-based modeling to explore the causes of this differential control. The simulated spheroids have increased macrophage activation. Surprisingly, this is not due to larger numbers of activated T cells, which activate these macrophages. Rather, the increase in activated macrophages is due to their proximity to fewer activated T cells. We also see a subset of simulations where the spheroids have increased cytotoxic CD8+ T cell activation. The simulation is further used to simulate changes in the structure of the in vitro models to explore its impact on immune response and bacterial control. These findings reveal the importance of structural complexity in in vitro models and offer insights into TB pathogenesis. Ultimately, our work paves the way for more realistic in vitro models and a deeper understanding of how our bodies combat TB. [ABSTRACT FROM AUTHOR]

Background: Aberrant activation of macrophages is associated with pathogenesis of acute lung injury (ALI). However, the potential pathogenesis has not been explored. Objectives: We aimed to identify whether histone deacetylase (HDAC) 10 is involved in lipopolysaccharide (LPS)-exposed ALI and reveal the underlying pathogenesis by which it promotes lung inflammation in LPS-exposed ALI via modifying P62 with deacetylation. Methods: We constructed an ALI mice model stimulated with LPS to determine the positive effect of Hdac10 deficiency. Moreover, we cultured murine alveolar macrophage cell line (MH-S cells) and primary bone marrow-derived macrophages (BMDMs) to explore the pro-inflammatory activity and mechanism of HDAC10 after LPS challenge. Results: HDAC10 expression was increased both in mice lung tissues and macrophage cell lines and promoted inflammatory cytokines production exposed to LPS. Hdac10 deficiency inhibited autophagy and inflammatory response after LPS stimulation. In vivo, Hdac10fl/fl-LysMCre mice considerably attenuated lung inflammation and inflammatory cytokines release exposed to LPS. Mechanistically, HDAC10 interacts with P62 and mediates P62 deacetylation at lysine 165 (K165), by which it promotes P62 expression and increases inflammatory cytokines production. Importantly, we identified that Salvianolic acid B (SAB), an HDAC10 inhibitor, reduces lung inflammatory response in LPS-stimulated ALI. Conclusion: These results uncover a previously unknown role for HDAC10 in regulating P62 deacetylation and aggravating lung inflammation in LPS-induced ALI, implicating that targeting HDAC10 is an effective therapy for LPS-exposed ALI. [ABSTRACT FROM AUTHOR]

Aim: Ferroptosis is a novel type of programmed cell death that performs a critical function in diabetic nephropathy (DN). Augmenter of liver regeneration (ALR) exists in the inner membrane of mitochondria, and inhibits inflammation, apoptosis, and oxidative stress in acute kidney injury; however, its role in DN remains unexplored. Here, we aimed to identify the role of ALR in ferroptosis induction and macrophage activation in DN. Methods: The expression of ALR was examined in DN patients, db/db DN mice, and HK‐2 cells treated with high glucose (HG). The effects of ALR on ferroptosis and macrophage activation were investigated with ALR conditional knockout, lentivirus transfection, transmission electron microscopy, qRT‐PCR and western blotting assay. Mass spectrometry and rescue experiments were conducted to determine the mechanism of ALR. Results: ALR expression was reduced in the kidney tissues of DN patients and mice, serum of DN patients, and HG‐HK‐2 cells. Moreover, the inhibition of ALR promoted ferroptosis, macrophage activation, and DN progression. Mechanistically, ALR can directly bind to carnitine palmitoyltransferase‐1A (CPT1A), the key rate‐limiting enzyme of fatty acid oxidation (FAO), and inhibit the expression of CPT1A to regulate lipid metabolism involving FAO and lipid droplet‐mitochondrial coupling in DN. Conclusion: Taken together, our findings revealed a crucial protective role of ALR in ferroptosis induction and macrophage activation in DN and identified it as an alternative diagnostic marker and therapeutic target for DN. [ABSTRACT FROM AUTHOR]

Summary: Previous studies demonstrated the interrelationship between antioxidant activity and solvent extracts prepared according to cultivars and plant parts of Centella asiatica (CA) cultivated in Korea. In this study, the macrophage‐stimulating activity of solvent extracts was assayed, and we analysed the characteristics of the active fractions of these extracts and the mechanisms underlying the macrophage‐stimulating activity of these fractions. Treatment of macrophages with cold water (CW) extracts (GO‐L‐CW) prepared from the leaves (L) of the 'GOOD' (GO) cultivar significantly increased the secretion of immunostimulatory factors. Specifically, the high molecular weight (HMW) fraction (GO‐L‐CW‐HMW) isolated from GO‐L‐CW potently activated the secretion of immunostimulatory factors and increased the mRNA levels of genes encoding these factors or involved in the production of these factors. In addition, GO‐L‐CW‐HMW triggered the phosphorylation of ERK and p38 of MAPK along with p65 and IκBα of the NF‐κB family in the intracellular signalling pathway. The GO‐L‐CW‐HMW was identified as a complex polysaccharide with a molecular weight of 93–129 kDa. In conclusion, polysaccharides present in GO‐L‐CW suggest the possibility of application as a new immunostimulating material. [ABSTRACT FROM AUTHOR]

Background: Extracellular vesicles (EVs) have been implicated in the pathogenesis of asthma, however, how EVs contribute to immune dysfunction and type 2 airway inflammation remains incompletely understood. We aimed to elucidate roles of airway EVs and their miRNA cargo in the pathogenesis of NSAID‐exacerbated respiratory disease (N‐ERD), a severe type 2 inflammatory condition. Methods: EVs were isolated from induced sputum or supernatants of cultured nasal polyp or turbinate tissues of N‐ERD patients or healthy controls by size‐exclusion chromatography and characterized by particle tracking, electron microscopy and miRNA sequencing. Functional effects of EV miRNAs on gene expression and mediator release by human macrophages or normal human bronchial epithelial cells (NHBEs) were studied by RNA sequencing, LC–MS/MS and multiplex cytokine assays. Results: EVs were highly abundant in secretions from the upper and lower airways of N‐ERD patients. N‐ERD airway EVs displayed profoundly altered immunostimulatory capacities and miRNA profiles compared to airway EVs of healthy individuals. Airway EVs of N‐ERD patients, but not of healthy individuals induced inflammatory cytokine (GM‐CSF and IL‐8) production by NHBEs. In macrophages, N‐ERD airway EVs exhibited an impaired potential to induce cytokine and prostanoid production, while enhancing M2 macrophage activation. Let‐7 family miRNAs were highly enriched in sputum EVs from N‐ERD patients and mimicked suppressive effects of N‐ERD EVs on macrophage activation. Conclusion: Aberrant airway EV miRNA profiles may contribute to immune dysfunction and chronic type 2 inflammation in N‐ERD. Let‐7 family miRNAs represent targets for correcting aberrant macrophage activation and mediator responses in N‐ERD. [ABSTRACT FROM AUTHOR]

Background and aim: Sepsis-induced acute lung injury (ALI) is a complex and life-threatening condition lacking specific and efficient clinical treatments. Extracellular histones, identified as a novel type of damage-associated molecular patterns, have been implicated in the inflammatory process of ALI. However, further elucidation is needed regarding the precise mechanism through which extracellular histones induce inflammation. The aim of this study was to investigate whether extracellular histones can activate NLRP3 inflammasome-mediated inflammation in alveolar macrophages (AMs) by affecting TWIK2-dependent potassium efflux. Methods and results: We conducted experiments using cecal ligation and puncture (CLP) C57BL/6 mice and extracellular histone-stimulated LPS-primed MH-S cells. The results demonstrated a significant increase in the levels of extracellular histones in the plasma and bronchoalveolar lavage fluid (BALF) of CLP mice. Furthermore, neutralizing extracellular histone mitigated lung injury and inflammation in CLP-induced ALI mice. In vitro studies confirmed that extracellular histones upregulated the expression of NLRP3 inflammasome activation-related proteins in MH-S cells, and this effect was dependent on increased potassium efflux mediated by the TWIK2 channel on the plasma membrane. Moreover, extracellular histones directly triggered a substantial influx of calcium, leading to increased Rab11 activity and facilitating the trafficking and location of TWIK2 to the plasma membrane. Conclusion: These findings underscore the critical role of extracellular histone-induced upregulation of TWIK2 expression on the plasma membrane of alveolar macrophages (AMs). This upregulation leads to potassium efflux and subsequent activation of the NLRP3 inflammasome, ultimately exacerbating lung inflammation and injury during sepsis. [ABSTRACT FROM AUTHOR]

Long noncoding RNAs (lncRNA) are emerging players in regulation of gene expression and cell signaling and their dysregulation has been implicated in a multitude of human diseases. Recent studies from our laboratory revealed that lncRNAs play critical roles in cytokine regulation, inflammation, and metabolism. We demonstrated that lncRNA HOTAIR, which is a well-known regulator of gene silencing, plays critical roles in modulation of cytokines and proinflammatory genes, and glucose metabolism in macrophages during inflammation. In addition, we recently discovered a series of novel lncRNAs that are closely associated with inflammation and macrophage activation. We termed these as long-noncoding inflammation associated RNAs (LinfRNAs). We are currently engaged in the functional characterization of these hLinfRNAs (human LinfRNAs) with a focus on their roles in inflammation, and we are investigating their potential implications in chronic inflammatory human diseases. Here, we have summarized experimental methods that have been utilized for the discovery and functional characterization of lncRNAs in inflammation and macrophage activation. [ABSTRACT FROM AUTHOR]

BACKGROUND: Vesicle-associated membrane protein 7 (VAMP7) plays oncogenic roles in cancers. However, its clinical significance in breast cancer (BC) tissues remains unknown. OBJECTIVE: To elucidate the clinical implications of VAMP7, as well as its involvement in the tumor microenvironment and molecular pathways of breast cancer. METHODS: BC (n = 100) and non-cancerous breast tissues (n = 100) were collected for an immunohistochemical experiment (1:200). The protein expression level of VAMP7 was determined by using a semi-quantitative scoring method. High-throughput RNA-sequencing data of BC tissues were analyzed to confirm the mRNA expression trend of VAMP7. Additionally, the largest BC prognosis cohort data were collected to mine the potential impact VAMP7 has on BC progression. The association between VAMP7 and the microenvironment of BC was evaluated by using a CIBERSORT algorithm. Moreover, we explored the co-expressed molecular mechanisms of VAMP7 in BC by calculating Pearson correlation coefficients and overexpressed genes. Finally, the biological mechanism underlying the relationship between VAMP7 and the key pathways was also explored using gene set enrichment analysis (GSEA). Potential therapeutic strategies were predicted targeting VAMP7. RESULTS: VAMP7 protein was significantly over-expressed in BC tissue than that in controls (p < 0.001). Compared with 459 normal breast tissues and 113 non-cancerous breast tissues, the expression level of VAMP7 mRNA was significantly increased in 1111 BC tissues. CD4+T cells, macrophages, and naïve B cells had a higher infiltration rate in BC tissues with high VAMP7 expression, while regulatory T cells and CD8+T cells had a lower infiltration rate. Over-expressed VAMP7 was associated with macrophages activation and transition from M1 to M2 polarization. Upregulated VAMP7 could predicted poorer OS, DMFS, PPS, and RFS outcomes. Upregulated VAMP7 co-expressed genes were significantly enriched in the cell cycle checkpoints. GSEA confirmed that over-expressed VAMP7 are markedly associated with functional enrichment in cell cycle related categories, including mitotic spindle, G2M checkpoint, and E2F targets. KU-55933 was predicted as a putative therapeutic drug for BC targeting VAMP7. CONCLUSIONS: VAMP7 was upregulated in BC tissue and correlated with poor prognosis of BC patients. VAMP7 may promote BC progression by targeting the cell cycle pathway. [ABSTRACT FROM AUTHOR]

Isoliquiritigenin (ISL) is a chalcone‐type flavonoid derived from the root of licorice with antioxidant, anti‐inflammatory, anti‐tumour and neuroprotective properties. ISL has been proven to downregulate the productions of IL‐1β, TNF‐α and IL‐6 by macrophages. However, detailed molecular mechanisms of this modulation remain elusive. Here, ISL suppressed Syk phosphorylation and CD80, CD86, IL‐1β, TNF‐α and IL‐6 expressions in lipopolysaccharide‐stimulated macrophages ex vivo. ApoC3‐transgenic (ApoC3TG) mice had more activated macrophages. ISL was also able to downregulate the inflammatory activities of macrophages from ApoC3TG mice. Administration of ISL inhibited Syk activation and inflammatory activities of macrophages in ApoC3TG mice in vivo. The treatment of ISL further alleviated MCD‐induced non‐alcoholic fatty liver disease (NAFLD) in wild‐type and ApoC3TG mice, accompanied by less recruitment and activation of liver macrophages. Due to the inhibition of Syk phosphorylation, ISL‐treated macrophages displayed less production of cytoplasmic ROS, NLRP3, cleaved‐GSDMD and cleaved‐IL‐1β, suggesting less inflammasome activation. Finally, the molecular docking study demonstrated that ISL bound to Syk directly with the Kd of 1.273 × 10−8 M. When the Syk expression was knocked down by its shRNA, the inhibitory effects of ISL on activated macrophages disappeared, indicating that Syk was at least one of key docking‐molecules of ISL. Collectively, ISL could alleviate MCD‐induced NAFLD in mice involved with the inhibition of macrophage inflammatory activity by the blockade of Syk‐induced inflammasome activation. [ABSTRACT FROM AUTHOR]

Background: Icariin (ICA) inhibits inflammatory response in various diseases, but the mechanism underlying ICA treating airway inflammation in asthma needs further understood. We aimed to predict and validate the potential targets of ICA against asthma‐associated airway inflammation using network pharmacology and experiments. Methods: The ovalbumin‐induced asthma‐associated airway inflammation mice model was established. The effects of ICA were evaluated by behavioral, airway hyperresponsiveness, lung pathological changes, inflammatory cell and cytokines counts. Next, the corresponding targets of ICA were mined via the SEA, CTD, HERB, PharmMapper, Symmap database and the literature. Pubmed‐Gene and GeneCards databases were used to screen asthma and airway inflammation‐related targets. The overlapping targets were used to build an interaction network, analyze gene ontology and enrich pathways. Subsequently, flow cytometry, quantitative real‐time PCR and western blotting were employed for validation. Results: ICA alleviated the airway inflammation of asthma; 402 targets of ICA, 5136 targets of asthma and 4531 targets of airway inflammation were screened; 216 overlapping targets were matched and predicted ICA possesses the potential to modulate asthmatic airway inflammation by macrophage activation/polarization. Additionally, ICA decreased M1 but elevated M2. Potential targets that were disrupted by asthma inflammation were restored by ICA treatment. Conclusions: ICA alleviates airway inflammation in asthma by inhibiting the M1 polarization of alveolar macrophages, which is related to metabolic reprogramming. Jun, Jak2, Syk, Tnf, Aldh2, Aldh9a1, Nos1, Nos2 and Nos3 represent potential targets of therapeutic intervention. The present study enhances understanding of the anti‐airway inflammation effects of ICA, especially in asthma. [ABSTRACT FROM AUTHOR]

It has been found that CD226 plays an important role in regulating macrophage function, but its expression and function in macrophages during renal fibrogenesis have not been studied. Our data demonstrated that CD226 expression in macrophages was obviously upregulated in the unilateral ureteral obstruction model, while CD226 deficiency attenuated collagen deposition in renal interstitium along with fewer M1 within renal cortex and renal medulla and a lower level of proinflammatory factors compared to that of control littermates. Further studies demonstrated that Cd226−/− bone marrow–derived macrophages transferring could significantly reduce the tubular injury, collagen deposition, and proinflammatory cytokine secretion compared with that of Cd226+/+ bone marrow–derived macrophages transferring in the unilateral ureteral obstruction model. Mechanistic investigations revealed that CD226 promoted proinflammatory M1 macrophage accumulation in the kidney via suppressing KLF4 expression in macrophages. Therefore, our results uncovered a pathogenic role of CD226 during the development of chronic kidney disease by promoting monocyte infiltration from peripheral blood into the kidney and enhancing macrophage activation toward the inflammatory phenotype by suppressing KLF4 expression. [ABSTRACT FROM AUTHOR]

Mangiferin is a naturally occurring glucosylxanthone that has shown promising immunomodulatory effects. It is generally isolated from the leaves, peels, bark, and kernels of Mangifera indica Linn. Mangiferin is like a miraculous natural bioactive molecule that has an immunomodulatory function that makes it a potential therapeutic candidate for the treatment of rheumatoid arthritis (RA) and cancer. The anticancer activity of mangiferin acts by blocking NF‐κB, as well as regulating the β‐catenin, EMT, MMP9, MMP2, LDH, ROS, and NO, and also by the activation of macrophages. It has no cytotoxic effect on grown chondrocytes and lowers matrix metalloproteinase levels. Additionally, it has a potent proapoptotic impact on synoviocytes. The precise molecular mechanism of action of mangiferin on RA and malignancies is still unknown. This comprehensive review elaborates on the immunomodulatory effect of mangiferin and its anticancer and anti‐RA activity. This also explained the total synthesis of mangiferin and its in vitro and in vivo screening models. [ABSTRACT FROM AUTHOR]

Introduction: Therapeutic antibodies have become a major strategy to treat oncologic diseases. For chronic lymphocytic leukemia, antibodies against CD20 are used to target and elicit cytotoxic responses against malignant B cells. However, efficacy is often compromised due to a suppressive microenvironment that interferes with cellular immune responses. To overcome this suppression, agonists of pattern recognition receptors have been studied which promote direct cytotoxicity or elicit anti-tumoral immune responses. NOD2 is an intracellular pattern recognition receptor that participates in the detection of peptidoglycan, a key component of bacterial cell walls. This detection then mediates the activation of multiple signaling pathways in myeloid cells. Although several NOD2 agonists are being used worldwide, the potential benefit of these agents in the context of antibody therapy has not been explored. Methods: Primary cells from healthy-donor volunteers (PBMCs, monocytes) or CLL patients (monocytes) were treated with versus without the NOD2 agonist L18-MDP, then antibody-mediated responses were assessed. In vivo, the EµTCL1 mouse model of CLL was used to test the effects of L18-MDP treatment alone and in combination with anti-CD20 antibody. Results: Treatment of peripheral blood mononuclear cells with L18-MDP led to activation of monocytes from both healthy donors and CLL patients. In addition, there was an upregulation of activating FcgR in monocytes and a subsequent increase in antibody-mediated phagocytosis. This effect required the NF-kB and p38 signaling pathways. Treatment with L18-MDP plus anti-CD20 antibody in the Eµ-TCL model of CLL led to a significant reduction of CLL load, as well as to phenotypic changes in splenic monocytes and macrophages. Conclusions: Taken together, these results suggest that NOD2 agonists help overturn the suppression of myeloid cells, and may improve the efficacy of antibody therapy for CLL. [ABSTRACT FROM AUTHOR]

Background: Inflammatory cytokines play key pathogenic roles in liver fibrosis. IL-15 is a proinflammatory cytokine produced by myeloid cells. IL-15 promotes pathogenesis of several chronic inflammatory diseases. However, increased liver fibrosis has been reported in mice lacking IL-15 receptor alpha chain (IL-15Ra), suggesting an anti-fibrogenic role for IL-15. As myeloid cells are key players in liver fibrosis and IL-15 signaling can occur independently of IL-15Ra, we investigated the requirement of IL-15 and IL-15Ra in liver fibrosis. Methods: We induced liver fibrosis in Il15-/-, Il15ra-/- and wildtype C57BL/6 mice by the administration of carbon tetrachloride (CCl4). Liver fibrosis was evaluated by Sirius red and Mason’s trichrome staining and a-smooth muscle acting immunostaining of myofibroblasts. Gene expression of collagens, matrix modifying enzymes, cytokines and chemokines was quantified by RT-qPCR. The phenotype and the numbers of intrahepatic lymphoid and myeloid cell subsets were evaluated by flow cytometry. Results: Both Il15-/- and Il15ra-/- mice developed markedly reduced liver fibrosis compared to wildtype control mice, as revealed by reduced collagen deposition and myofibroblast content. Il15ra-/- mice showed further reduction in collagen deposition compared to Il15-/- mice. However, Col1a1 and Col1a3 genes were similarly induced in the fibrotic livers of wildtype, Il15-/- and Il15ra-/- mice, although notable variations were observed in the expression of matrix remodeling enzymes and chemokines. As expected, Il15-/- and Il15ra-/- mice showed markedly reduced numbers of NK cells compared to wildtype mice. They also showed markedly less staining of CD45+ immune cells and CD68+ macrophages, and significantly reduced inflammatory cell infiltration into the liver, with fewer pro-inflammatory and antiinflammatory monocyte subsets compared to wildtype mice. Conclusion: Our findings indicate that IL-15 exerts its profibrogenic role in the liver by promoting macrophage activation and that this requires transpresentation of IL-15 by IL-15Ra. [ABSTRACT FROM AUTHOR]

Background: Extended contact with silica particles can lead to Silicosis, a chronic lung condition lacking established treatment protocols or clear mechanisms of development. The urgency for innovative treatments arises from the unavailability of effective treatment methodologies. The origin of silica-induced pulmonary fibrosis includes essential processes such as macrophage activation and the conversion of fibroblasts into myofibroblasts, with oxidative stress playing a pivotal role. Shionone (SHI), a triterpenoid extracted from the Aster tataricus plant, is recognized for its extensive health benefits. This study explores the capability of SHI to alleviate the effects of silica-induced lung fibrosis in mice. Methods: This investigation explored the impact of SHI on lung inflammation and fibrosis at different stages (early and late) triggered by silica in mice, focusing specifically on the initial and more developed phases. It comprised an analysis of isolated peritoneal macrophages and fibroblasts extracted from mice to elucidate SHI's therapeutic potential and its underlying mechanism. The methodology employed encompassed quantitative PCR, immunofluorescence, flow cytometry, and western blotting to examine macrophage activity and their transition into myofibroblasts. The activation of the nuclear factor erythroid 2-related factor 2 (Nrf2) pathway by SHI was confirmed via immunofluorescence and western blot studies. SHI's antioxidative properties were evidenced by the measurement of reactive oxygen species (ROS) and mitochondrial ROS within both macrophages and fibroblasts, using 2′, 7′-dichlorodihydrofluorescein diacetate and MitoSOX, respectively. The relevance of SHI was further underscored by applying ML385 and Nrf2 siRNA to gauge its effectiveness. Results: Starting SHI treatment early countered the harmful effects of lung inflammation and fibrosis caused by silica, while initiating SHI at a later phase decelerated the advancement of fibrosis. SHI's action was linked to the activation of the Nrf2 signaling pathway, a boost in antioxidant enzyme levels, and a decrease in oxidative stress and inflammation in macrophages affected by silica. Furthermore, SHI prevented the conversion of fibroblasts into myofibroblasts prompted by TGF-β, along with the resultant oxidative stress. The beneficial outcomes of SHI were negated when ML385 and Nrf2 siRNA were applied, highlighting the pivotal role of the Nrf2 pathway in SHI's efficacy. Conclusion: SHI plays a significant role in stimulating the Nrf2 pathway, thereby defending against silica-induced oxidative stress and inflammatory reactions in macrophages, and inhibiting the conversion of fibroblasts to myofibroblasts due to TGF-β. This suggests that SHI is a viable option for treating lung inflammation and fibrosis in mice suffering from silicosis. [ABSTRACT FROM AUTHOR]

Human milk oligosaccharides (HMOs) are present in high numbers in milk of lactating women. They are beneficial to gut health and the habitant microbiota, but less is known about their effect on cells from the immune system. In this study, we investigated the direct effect of three structurally different HMOs on human derived macrophages before challenge with Staphylococcus aureus (S. aureus). The study demonstrates that individual HMO structures potently affect the activation, differentiation and development of monocyte-derived macrophages in response to S. aureus. 6´-Sialyllactose (6’SL) had the most pronounced effect on the immune response against S. aureus, as illustrated by altered expression of macrophage surface markers, pointing towards an activated M1-like macrophage-phenotype. Similarly, 6’SL increased production of the pro-inflammatory cytokines TNF-α, IL-6, IL-8, IFN-γ and IL-1β, when exposing cells to 6’SL in combination with S. aureus compared with S. aureus alone. Interestingly, macrophages treated with 6’SL exhibited an altered proliferation profile and increased the production of the classic M1 transcription factor NF-κB. The HMOs also enhanced macrophage phagocytosis and uptake of S. aureus. Importantly, the different HMOs did not notably affect macrophage activation and differentiation without S. aureus exposure. Together, these findings show that HMOs can potently augment the immune response against S. aureus, without causing inflammatory activation in the absence of S. aureus, suggesting that HMOs assist the immune system in targeting important pathogens during early infancy. [ABSTRACT FROM AUTHOR]

Nanostructured surfaces are effective at physically killing bacterial cells, highlighting their prospective application as biomaterials. The benefits of application of mechano‐bactericidal nanostructures as an alternative to chemical functionalisation are well documented, however, the effects of protein adsorption are not well understood. In this work, theoretical and experimental analyses are conducted by studying the adsorption of human serum proteins (HSP) to nanosheet titanium (Ti) and its subsequent effect on the mechano‐bactericidal efficacy toward Staphylococcus aureus and Pseudomonas aeruginosa cells. The nanosheet pattern exhibits enhanced antibiofouling behaviour mantaining high bactericidal efficiency toward both Gram‐negative and Gram‐positive cells in the presence of adsorbed HSP. To ascertain the immunomodulatory response, S. aureus cells are introduced to protein‐conditioned Ti nanosheet surfaces prior to introducing RAW 264.7 macrophages. On the pre‐infected nanostructured surfaces, macrophages exhibit wound healing behaviour with superior activation of M2‐like macrophage polarization and secretion of anti‐inflammatory cytokines. By contrast, macrophages attached to infected smooth surfaces activated the M1‐like polarized phenotype via the high expression of pro‐inflammatory cytokines, indicating persistent inflammation. The outcomes of this work demonstrate the suitability of Ti nanosheets as a potential biomaterial surface whereby the mechano‐bactericidal activity is not compromised by HSP adsorption and, furthermore, positively influenced an anti‐inflammatory immune response. [ABSTRACT FROM AUTHOR]

Cancer immunotherapy is a pillar of clinical oncology but only achieves long-term remissions in a minority of cases. In this issue, van Elsas et al. show that effective immunotherapy requires a series of processes orchestrated by CD8+ T cells that result in the recruitment and local activation of M1-like macrophages. [ABSTRACT FROM AUTHOR]

Heart failure with preserved ejection fraction (HFpEF) is a multifaceted pathogenesis disease and the exact mechanisms driving HFpEF have not been completely elucidated. Pressure overload hypertrophy (POH) related fibroblasts and M2 macrophages in HFpEF myocardium have been recently identified and are now of great interest. Sympathetic overdrive has also been implicated in HFpEF. This study is designed to dynamically observe the potential roles of aforementioned mechanisms in pathological remodeling and cardiac dysfunction in chronic PO rats. Surgical constriction of the abdominal aorta was used for induction of HFpEF. Echocardiography, electrocardiogram, hemodynamic measurement, hematoxylin and eosin staining, Masson staining, immunohistochemistry and immunofluorescence were performed to assess the changes in heart dysfunction, cardiac remodeling and driving mechanisms at different time points (2, 18, 24 weeks). The PO induced HFpEF model was well established, which was confirmed by the persistent increase in carotid artery systolic and diastolic blood pressure, and left ventricle hypertrophy at the corresponding postoperative stage. Meanwhile, PO hypertrophy gradually developed into HFpEF, associated with QT and QTc intervals prolongation, normal systolic (EF was maintained at >50%) but impaired diastolic function (increasing LVEDP and LV -dP/dtmin, abnormal E/A ratio), increased myocytes size, and observed relatively slight inflammatory infiltration but robust reactive fibrosis. IHC staining further confirmed that macrophages (CD68) but not neutrophils (MPO) or T cells (CD3) accounted for a predominant proportion of infiltrating cells. Mechanistically, we found that the infiltrating macrophages in the heart expressed high levels of CD206 which was simultaneously adjacent to POH fibroblasts appeared to overexpression of α-SMA in PO rats at late stages. Interestingly, we distinguished two different POHF sub-populations during PO induced HFpEF development, according to non overlapping signals of α-SMA and PDGFRα/β proteins. Additionally, PO led to a pronounced exaggeration in sympathetic fibers at all time points. These findings suggest that the establishing model here begins with cardiac sympathetic overdrive, subsequently along with immune cells especially M2 macrophage accumulation and fibroblast heterogeneity at later stages is associated with the development of cardiac maladaptive remodeling and diastolic dysfunction thus further progression to HFpEF. [ABSTRACT FROM AUTHOR]

More than 500 kinases are implicated in the control of most cellular process in mammals, and deregulation of their activity is linked to cancer and inflammatory disorders. 80 clinical kinase inhibitors (CKIs) have been approved for clinical use and hundreds are in various stages of development. However, CKIs inhibit other kinases in addition to the intended target(s), causing both enhanced clinical effects and undesired side effects that are only partially predictable based on in vitro selectivity profiling. Here, we report an integrative approach grounded on the use of chromatin modifications as unbiased, information-rich readouts of the functional effects of CKIs on macrophage activation. This approach exceeded the performance of transcriptome-based approaches and allowed us to identify similarities and differences among CKIs with identical intended targets, to recognize novel CKI specificities and to pinpoint CKIs that may be repurposed to control inflammation, thus supporting the utility of this strategy to improve selection and use of CKIs in clinical settings. Synopsis: Unbiased genome-wide analyses of epigenomic alterations induced by clinical kinase inhibitors (CKIs) in macrophages activated by inflammatory stimuli allow identifying insofar unknown similarities and differences among CKIs, improving their annotations and showing opportunities for repurposing. A genome-wide analysis was developed that exploits epigenetic changes as unbiased, high-content and information-rich read-outs of CKIs' effects. Effects of CKIs on epigenomic changes induced by macrophage activation can be explained by drug-specific combinations of on-target and off-target effects on different sets of signal-regulated transcription factors. CKIs with similar intended annotated target(s) show only partially overlapping epigenomic effects. Conversely, similarities among CKIs with distinct annotations indicate opportunities for drug repurposing. An epigenomic readout was shown to exceed transcription-based analyses in capturing functional effects of CKIs and similarities among them. Unbiased genome-wide analyses of epigenomic alterations induced by clinical kinase inhibitors (CKIs) in macrophages activated by inflammatory stimuli allow identifying insofar unknown similarities and differences among CKIs, improving their annotations and showing opportunities for repurposing. [ABSTRACT FROM AUTHOR]