M1/M2 macrophages and their overlaps - myth or reality?

The secretomes of bovine mammary epithelial cell subpopulations differentially modulate macrophage function

Bovine mammosphere-derived epithelial cell (MDEC) cultures are heterogeneous and enriched for stem and progenitor cells. We previously reported that the bovine MDEC secretome, comprised of all bioactive factors secreted by the cells, displays regenerative properties, exerts antimicrobial effects, and modulates neutrophil activity, positioning it as a promising non-antibiotic biologic therapy for infectious diseases important to the dairy industry, like mastitis. Mastitis is defined as inflammation of the udder, and it is typically caused by bacterial infection. The effect of the MDEC secretome on macrophages, a first line of defense against bacterial infections in the udder, is unknown and could impact the utility of the secretome as a therapy for mastitis. To address this, we isolated bovine monocytes from peripheral blood and maintained them as an unpolarized (M0) population or polarized them into M1 or M2 phenotypes. Macrophages cultured with the secretome of bovine MDECs were assessed for their ability to phagocytose labeled bacterial particles and accumulate reactive oxygen species (ROS). We used single-cell RNA sequencing (scRNA-seq) and fluorescence-activated cell sorting (FACS) to isolate a subpopulation of MDECs that exert enhanced effects on macrophages. We found that the secretome of MDECs that do not express cluster of differentiation (CD) 73, a cell surface enzyme used as a marker for mesenchymal stromal cells, most strongly increased macrophage phagocytosis and ROS accumulation. These findings will help optimize the generation of the bovine MDEC secretome as a suitable treatment option for mastitis.

Decoding the immune landscape in Ewing sarcoma pathogenesis: The role of tumor infiltrating immune cells and immune milieu

Ewing sarcoma (EwS) is the second most prevalent pediatric bone malignancy, characterized by its aggressive behavior and unfavorable prognosis. The tumor microenvironment (TME) of EwS is shaped by immunosuppressive components, including myeloid-derived suppressor cells, tumor-associated macrophages, and immune checkpoint molecules such as PD-1/PD-L1 and HLA-G. These elements impair anti-tumor immune responses by modulating the function of tumor-infiltrating immune cells, such as regulatory T cells (Tregs), CD8+ T cells, and natural killer cells. Chemokines, including CXCL9 and CXCL12, and cytokines, such as transforming growth factor-beta and interleukin-10, further contribute to immune suppression and promote metastatic dissemination. Recent advances in immunotherapy have highlighted the therapeutic potential of modulating immune cells and signaling pathways to enhance anti-tumor immunity. This review provides a comprehensive analysis of the complex immune landscape within the EwS TME, focusing on the mechanistic roles of key immune components and their potential as therapeutic targets. Understanding these interactions could pave the way for innovative treatment strategies to improve clinical outcomes in patients with EwS.

MicroRNA-122-5p is upregulated in diabetic foot ulcers and decelerates the transition from the inflammatory to the proliferative stage

BACKGROUND

Shifting from the inflammatory to the proliferative phase represents a pivotal step during managing diabetic foot ulcers (DFUs); however, existing medical interventions remain insufficient. MicroRNAs (miRs) highlight notable capacity for accelerating the repair process of DFUs. Previous research has demonstrated which miR-122-5p regulates matrix metalloproteinases under diabetic conditions, thereby influencing extracellular matrix dynamics.

AIM

To investigate the impact of miR-122-5p on the transition from the inflammatory to the proliferative stage in DFU.

METHODS

Analysis for miR-122-5p expression in skin tissues from diabetic ulcer patients and mice was analyzed using quantitative real-time polymerase chain reaction (qRT-PCR). A diabetic wound healing model induced by streptozotocin was used, with mice receiving intradermal injections of adeno-associated virus -DJ encoding empty vector or miR-122. Skin tissues were retrieved at 3, 7, and 14 days after injury for gene expression analysis, histology, immunohistochemistry, and network studies. The study explored miR-122-5p's role in macrophage-fibroblast interactions and its effect on transitioning from inflammation to proliferation in DFU healing.

RESULTS

High-throughput sequencing revealed miR-122-5p as crucial for DFU healing. qRT-PCR showed significant upregulation of miR-122-5p within diabetic skin among DFU individuals and mice. Western blot, along with immunohistochemical and enzyme-linked immunosorbent assay, demonstrating the upregulation of inflammatory mediators (hypoxia inducible factor-1α, matrix metalloproteinase 9, tumor necrosis factor-α) and reduced fibrosis markers (fibronectin 1, α-smooth muscle actin) by targeting vascular endothelial growth factor. Fluorescence in situ hybridization indicated its expression localized to epidermal keratinocytes and fibroblasts in diabetic mice. Immunofluorescence revealed enhanced increased presence of M1 macrophages and reduced M2 polarization, highlighting its role in inflammation. MiR-122-5p elevated inflammatory cytokine levels while suppressing fibrotic activity from fibroblasts exposed to macrophage-derived media, highlighting its pivotal role in regulating DFU healing.

CONCLUSION

MiR-122-5p impedes cutaneous healing of diabetic mice via enhancing inflammation and inhibiting fibrosis, offering insights into miR roles in human skin wound repair.

Transcriptomic landscape around wound bed defines regenerative versus non-regenerative outcomes in mouse digit amputation

In the mouse distal terminal phalanx (P3), it remains mystery why amputation at less than 33% of the digit results in regeneration, while amputation exceeding 67% leads to non-regeneration. Unraveling the molecular mechanisms underlying this disparity could provide crucial insights for regenerative medicine. In this study, we aim to investigate the tissues within the wound bed to understand the tissue microenvironment associated with regenerative versus non-regenerative outcomes. We employed a P3-specific amputation model in mice, integrated with time-series RNA-seq and a macrophage assay challenged with pro- and anti-inflammatory cytokines, to explore these mechanisms. Our findings revealed that non-regenerative digits exhibit a greater intense early transcriptional response in the wound bed compared to regenerative ones. Furthermore, early macrophage phenotypes differ distinctly between regenerative and non-regenerative outcomes. Regenerative digits also display unique co-expression modules related to Bone Morphogenetic Protein 2 (Bmp2). The differentially expressed genes (DEGs) between regenerative and non-regenerative digits are enriched in targets of several transcription factors, such as HOXA11 and HOXD11 from the HOX gene family, showing a time-dependent pattern of enrichment. These transcription factors, known for their roles in bone regeneration, skeletal patterning, osteoblast activity, fracture healing, angiogenesis, and key signaling pathways, may act as master regulators of the regenerative gene signatures. Additionally, we developed a deep learning AI model capable of predicting post-amputation time and level from RNA-seq data, indicating that the regenerative probability may be "encoded" in the transcriptomic response to amputation.

Transcriptomic characterization of human pancreatic CD206- and CD206 + macrophages

Macrophages reside in all organs and participate in homeostatic- and immune regulative processes. Little is known about pancreatic macrophage gene expression. In the present study, global gene expression was characterized in human pancreatic macrophage subpopulations. CD206- and CD206 + macrophages were sorted separately from pancreatic islets and exocrine tissue to high purity using flow cytometry, followed by RNA-seq analysis. Comparing CD206- with CD206 + macrophages, CD206- showed enrichment in histones, proliferation and cell cycle regulation, glycolysis and SPP1-associated immunosuppressive polarization while CD206 + showed enrichment in complement and coagulation-, IL-10 and IL-2RA immune regulation, as well as scavenging-related gene sets. Comparing islet CD206- with exocrine CD206-, enrichments in islet samples included two sets involved in immune regulation, while enrichments in exocrine samples included sets related to extracellular matrix and immune activation. Fewer differences were found between CD206 + macrophages, with enrichments in islet samples including two IL2-RA related gene sets, while enrichments in exocrine samples included sets related to extracellular matrix and immune activation. Comparing macrophages between individuals with normoglycemia, elevated HbA1c or type 2 diabetes, only a few diverse differentially expressed genes were identified. This work characterizes global gene expression and identifies differences between CD206- and CD206 + macrophage populations within the human pancreas.

Modulation of M1 and M2 macrophage polarization by metformin: Implications for inflammatory diseases and malignant tumors

Macrophages perform an essential role in the body's defense mechanisms and tissue homeostasis. These cells exhibit plasticity and are categorized into two phenotypes, including classically activated/M1 pro-inflammatory and alternatively activated/M2 anti-inflammatory phenotypes. Functional deviation in macrophage polarization occurs in different pathological conditions that need correction. In addition to antidiabetic impacts, metformin also possesses multiple biological activities, including immunomodulatory, anti-inflammatory, anti-tumorigenic, anti-aging, cardioprotective, hepatoprotective, and tissue-regenerative properties. Metformin can influence the polarization of macrophages toward M1 and M2 phenotypes. The ability of metformin to support M2 polarization and suppress M1 polarization could enhance its anti-inflammatory properties and potentiate its protective effects in conditions such as chronic inflammatory diseases, atherosclerosis, and obesity. However, in metformin-treated tumors, the proportion of M2 macrophages is decreased, while the frequency ratio of M1 macrophages is increased, indicating that metformin can modulate macrophage polarization from a pro-tumoral M2 state to an anti-tumoral M1 phenotype in malignancies. Metformin affects macrophage polarization through AMPK-dependent and independent pathways involving factors, such as NF-κB, mTOR, ATF, AKT/AS160, SIRT1, STAT3, HO-1, PGC-1α/PPAR-γ, and NLRP3 inflammasome. By modulating cellular metabolism and apoptosis, metformin can also influence macrophage polarization. This review provides comprehensive evidence regarding metformin's effects on macrophage polarization and the underlying mechanisms. The polarization-inducing capabilities of metformin may provide significant therapeutic applications in various inflammatory diseases and malignant tumors.

Identification of biomarkers associated with M1 macrophages in the ST-segment elevation myocardial infarction through bioinformatics and machine learning approaches

ST-segment elevation myocardial infarction (STEMI) is considered a critical cardiac condition with a poor prognosis. Shortly after STEMI occurs, the increased number of circulating leukocytes including macrophages can lead to the accumulation of more cells in the myocardium, affecting the cardiac immune microenvironment. Identifying serum biomarkers associated with immune infiltration after STEMI is important for diagnosing and treating STEMI. In this work, we aimed to use integrated bioinformatics and machine learning methods to identify new biomarkers. First, candidate genes closely associated with M1 macrophage immune infiltration and STEMI were obtained using the limma package, the CIBERSORTx package, weighted gene coexpression network analysis (WGCNA), and protein‒protein interaction (PPI) networks from the GSE59867 dataset, which comprises peripheral blood mononuclear cell (PBMC) samples. The STEMI patients were subsequently stratified into subtypes using the ConsensusClusterPlus package. Furthermore, using machine learning methods, we identified AKT3, GJC2, HMGCL and RBM17 as the genes with the greatest potential to be associated with STEMI subtypes and with M1 macrophage infiltration during the acute phase of STEMI. Finally, the expression profile and diagnostic value of the four feature genes were validated in the GSE59867 and GSE62646 datasets and in 24 patients using real-time PCR. This study revealed logically and comprehensively that AKT3, GJC2, HMGCL and RBM17, which are derived from PBMCs, could enhance the accuracy of STEMI diagnosis and might provide effective treatment options for STEMI patients.

Evaluation of Electrospun Poly-4-Hydroxybutyrate as Biofunctional and Degradable Scaffold for Pelvic Organ Prolapse in a Vaginal Sheep Model

Pelvic organ prolapse (POP) affects many women, especially after menopause. POP occurs due to the descent of weakened supportive tissue. Current prolapse surgeries have high failure rates, due to disturbed wound healing caused by lower tissue regeneration and estrogen depletion. Absorbable poly-4-hydroxybutyrate (P4HB) knit implants exhibited improved cell and tissue response leading to less complications from prolapse surgery. This study aims to enhance wound healing and improve surgical outcomes by using an electrospun (ES) P4HB scaffold (ES P4HB) that emulates natural tissue structure. Further 17β-estradiol (E2)-a prominent wound healing factor-is incorporated into the scaffold (ES P4HB-E2). Parous Dohne Merino sheep underwent posterior vaginal wall implantation of either P4HB (n = 6) or 17β-estradiol relasing P4HB-E2 (n = 6) scaffolds, or underwent native tissue repair (NTR) (n = 4). Vaginal explants were compared for short-term host response in terms of gross necropsy, histomorphology, biomechanics, tissue-integration, and degradation of P4HB at 3-months post-implantation. Both scaffolds show promising results with enhanced mechanical properties and increased macrophage infiltration compared to NTR, but without differences between scaffolds. Thus, it seems electrospun P4HB scaffolds already improve tissue integration and healing. Further long-term studies are needed before these scaffolds can be used in clinical practice.

Overexpression of ABCA1 in Carotid Endothelium of Hyperlipidemic Rabbits Modulates Vascular Inflammation

Endothelial activation and dysfunction are key early steps in atherogenesis. Vascular gene therapy targeting endothelial inflammation and cholesterol accumulation could decrease atherosclerosis progression. ATP-binding cassette subfamily A member 1 (ABCA1) exhibits anti-inflammatory properties and promotes cholesterol efflux. A mouse model showed that systemic endothelial overexpression of ABCA1 decreased diet-induced atherosclerosis. To test if local ABCA1 endothelial overexpression protects against atherosclerosis, we used helper-dependent adenoviral vectors (HDAd) to express ABCA1 or a "Null" control in the carotid endothelium of hyperlipidemic rabbits. Both ABCA1 mRNA and endothelial protein were increased 3 days after vector infusion. After 24 weeks on a high-fat diet, laser-microdissected endothelium showed increased ABCA1 mRNA expression, but whole-vessel ABCA1 mRNA was decreased with HDAdABCA1. Endothelial ABCA1 protein could not be measured at 24 weeks, so its overexpression may be transient. CD68 expression was decreased (-23%, p < 0.001), but ITGAM (-15%, p = 0.3) was unchanged. Macrophage markers for both M1-like macrophages (IL1B: -44% [p = 0.02]; IL6: -40% [p = 0.02]; CCL2: -25% [p = 0.02]) and M2-like macrophages (ARG1: -27% [p = 0.03]; IL10: -23% [p = 0.09]; TGFB1: -13% [p < 0.001]) were also decreased. The inflammatory cytokines IL6 (-100%; p < 0.001) and TNF (p < 0.05) were significantly decreased in the laser-microdissected endothelium, but VCAM1 (+5%, p = 1.0) was unchanged and ICAM1 (+101%; p = 0.03) increased. Lesion size, intimal lipid, and intimal macrophage content were all unchanged (p > 0.5 for all), and vascular cholesterol measured by mass spectrometry (-11%; p = 0.9) also showed no difference. There was a small decrease in the intimal/medial ratio. scRNAseq revealed that vector transcripts were not restricted to endothelial cells after 24+ weeks but were detected in most cell types. The exception was modulated smooth muscle cells, which were found in substantial numbers in larger lesions. Overall, transient overexpression of ABCA1 in the vascular endothelium subtly alters the expression of inflammatory markers, providing only a modest atheroprotection.

Topology-dependent T2 relaxivity in Fe3O cluster-based MOFs for enhanced tumor monitoring via MRI

Metal-organic frameworks (MOFs) are crystalline porous materials with tunable structures, where metal ions or clusters serve as magnetic centers and organic ligands offer spatial separation. These characteristics, combined with their diverse topologies, make MOFs promising candidates for contrast agents (CAs) in magnetic resonance imaging (MRI). Herein we synthesized four MOFs based on the same triangular Fe3O clusters with different topologies: MIL-101(Fe) (moo net), MIL-100(Fe) (mtn net), MIL-59(Fe) (pcu net), and MIL-88B(Fe) (acs net). To clarify the relationship between topologies and T2 relaxivities, the MOFs were tailored into uniform, nanoscale spherical morphologies. Notably, the value of T2 relaxivity for MIL-88B(Fe) with acs topology is nearly three times that for MIL-101(Fe) with moo topology at 7.0 T. By comparing the magnetic properties of Fe3O molecular clusters and Ga-doped MIL-88B(Fe), our analysis demonstrated the significant advantage of MOFs with fixed arrays, adjustable components and diverse topologies in enhancing magnetic relaxation. Cellular MRI experiments further revealed that MIL-88B(Fe) could differentiate between M1 and M2 macrophages, highlighting its potential for monitoring tumor progression. These findings offer valuable insights into how MOF topology can be strategically utilized to enhance T2 relaxivities for MRI applications.

A Broad-Spectrum Chemokine Inhibitor Drives M2 Macrophage Polarization Through Modulation of the Myometrial Secretome

The uterine smooth muscle (myometrium) is an immunomodulatory tissue capable of secreting multiple chemokines during pregnancy. We propose that before term labor, chemokines secreted as a result of mechanical stretch of the uterine walls by the growing fetus(es) induce infiltration of maternal monocytes into myometrium, drive their differentiation into macrophages, and induce pro-inflammatory (M1) polarization, leading to labor contractions. This study used high-throughput proteomic mass-spectrometry to investigate the underlying mechanisms and explored the therapeutic potential of a broad-spectrum chemokine inhibitor (BSCI, FX125L) in modulating these effects. Primary myocytes isolated from the myometrium of term pregnant women were subjected in vitro to static mechanical stretch. Proteomic analysis of stretched myocyte-conditioned media (CM) identified significant upregulation of chemokine-related pathways and ECM degradation proteins. CM induced in vitro differentiation of human monocytes to macrophages and polarization into an M1-like phenotype characterized by elevated ROS production. BSCI treatment altered the myocyte secretome, increasing tissue-remodeling and anti-inflammatory proteins, Annexin A1 and TGF-β. BSCI-treated myocyte secretions induced Annexin A1 expression in macrophages and enhanced their phagocytic activity. We conclude that factors secreted by mechanically stretched myocytes induce pro-inflammatory M1 macrophage polarization, while BSCI modulates myocyte secretome, which reprograms macrophages to a homeostatic M2-like phenotype, thus reducing inflammation. When treated with BSCI, M2-polarized macrophages reduced myocyte-driven collagen gel contraction, whereas M1 macrophages enhanced it. This study reveals novel insights into the myocyte-macrophage interaction and identifies BSCI as a promising drug to modulate myometrial activity. We suggest that uterine macrophages may represent a therapeutic target for preventing preterm labor in women.

Toll-like receptors in kidney ischemia-reperfusion injury: Modulating macrophage responses for therapeutic insights

Kidney ischemia-reperfusion (I/R) injury is an acute clinical condition associated with inflammation and tissue damage during and after ischemia and reperfusion periods. In I/R injury, macrophages contribute to injury, and a family of proteins called toll-like receptors seem to have an immune modulatory role. When activated, TLRs initiate a series of signaling pathways, including MyD88 and TRIF. These pathways regulate the activation of tissue macrophages into either 'classically activated' M1 or 'alternatively activated' M2 phenotypes. Indeed, the relative abundance of these macrophage phenotypes defines the tissue injury level, which consequently requires reparative processes. The initial effector pro-inflammatory M1 macrophages aggravate tissue injury. Conversely, tissue reparative and anti-inflammatory M2 macrophages promote tissue repair and resolution-increased TLR signalling results in increased inflammation, prolonged healing and even renal failure. New evidence indicates that the change of macrophage responses through pharmacological targeting of the TLR pathways that regulate inflammation and tissue repair may have therapeutic implications. Some experimental treatment methods, in which early phases have been elaborated through experimental animal models, are TLR antagonists, small molecule inhibitors and nanotechnology-based delivery systems for Antisense oligonucleotide. Nevertheless, because the pathways regulated by TLRs and the subsets of macrophages are so countless and entangled, more extensive study is needed to provide more targeted actions. These findings shed light on the role and regulation of TLRs in macrophages during kidney I/R injury and investigate potential treatments with the potential to enhance care in this highly damaging condition.

Microenvironment-based immunotherapy in oral cancer: a comprehensive review

Oral cancer, a prevalent form of head and neck malignancy, accounts for 4% of global cancer cases. The most common type, oral squamous cell carcinoma (OSCC), has a survival rate of about 50%. Even though emerging molecular therapies show promise for managing oral cancer, current treatments like surgery, radiotherapy, and chemotherapy have significant side effects. In addition, the complex tumor microenvironment (TME), involving the extracellular matrix (ECM) and cells like fibroblasts and stromal cells like immune cells, promotes tumor growth and inhibits immune responses, complicating treatment. Nonetheless, immunotherapy is crucial in cancer treatment, especially in oral cancers. Indeed, its effectiveness lies in targeting immune checkpoints such as PD-1 and CTLA-4 inhibitors, as well as monoclonal antibodies like pembrolizumab and cetuximab, adoptive cell transfer methods (including CAR-T cell therapy), cytokine therapy such as IL-2, and tumor vaccines. Thus, these interventions collectively regulate tumor proliferation and metastasis by targeting the TME through autocrine-paracrine signaling pathways. Immunotherapy indeed aims to stimulate the immune system, leveraging both innate and adaptive immunity to counteract cancer cell signals and promote tumor destruction. This review will explore how the TME controls tumor proliferation and metastasis via autocrine-paracrine signaling pathways. It will then detail the effectiveness of immunotherapy in oral cancers, focusing on immune checkpoints, targeted monoclonal antibodies, adoptive cell transfer, cytokine therapy, and tumor vaccines.

The role of macrophages in hypertrophic scarring: molecular to therapeutic insights

Hypertrophic Scar (HS) is a common fibrotic disease of the skin, usually caused by injury to the deep dermis due to trauma, burns, or surgical injury. The main feature of HS is the thickening and hardening of the skin, often accompanied by itching and pain, which seriously affects the patient's quality of life. Macrophages are involved in all stages of HS genesis through phenotypic changes. M1-type macrophages primarily function in the early inflammatory phase by secreting pro-inflammatory factors, while M2-type macrophages actively contribute to tissue repair and fibrosis. Despite advances in understanding HS pathogenesis, the precise mechanisms linking macrophage phenotypic changes to fibrosis remain incompletely elucidated. This review addresses these gaps by discussing the pathological mechanisms of HS formation, the phenotypic changes of macrophages at different stages of HS formation, and the pathways through which macrophages influence HS progression. Furthermore, emerging technologies for HS treatment and novel therapeutic strategies targeting macrophages are highlighted, offering potential avenues for improved prevention and treatment of HS.

Sinhyotaklisan alleviates inflammation in LPS-activated macrophages by modulating the heme oxygenase pathway

ETHNOPHARMACOLOGICAL RELEVANCE

Shinhyotaklisan (SHTLS) is a time-honored traditional Korean herbal formula composed of four key herbs: Lonicerae Flos, Astragali Radix, Angelicae Gigantis Radix, and Glycyrrhizae Radix et Rhizoma. It has been extensively used to treat inflammatory diseases by expelling excessive heat, detoxifying the body, and promoting the drainage of pus from abscesses.

AIM OF THE STUDY

This study examines the therapeutic effects of SHTLS and elucidates its mechanisms of action in alleviating lipopolysaccharide (LPS)-induced inflammation in vitro.

MATERIALS AND METHODS

SHTLS was prepared by boiling four herbs in 30% ethanol, and its antioxidant and antimicrobial effects were assessed. Furthermore, SHTLS was applied to LPS-exposed RAW 264.7 cells, and its anti-inflammatory effects were evaluated using an MTT assay, nitric oxide (NO) and reactive oxygen species (ROS) assays, enzyme-linked immunosorbent assay, and western blotting.

RESULTS

SHTLS demonstrated potent antioxidant and antimicrobial effects. It effectively suppressed LPS-induced inflammatory cascades, resulting in a significant reduction in pro-inflammatory cytokines, including IL-6 and TNF-α, in murine macrophage cells. Moreover, SHTLS decreased COX-2 and iNOS expression levels, primarily through the inhibition of NF-κB and MAPK signaling pathways. Additionally, SHTLS significantly reduced intracellular ROS and reactive nitrogen species levels by upregulating heme oxygenase-1 (HO-1) expression. The anti-inflammatory effects of SHTLS were diminished by the addition of an HO-1 inhibitor, underscoring its strong association with intracellular antioxidant mechanisms.

CONCLUSION

Our results suggest that SHTLS exhibits strong antioxidant and anti-inflammatory effects, primarily by upregulating HO-1 and inhibiting the NF-κB and MAPK pathways, highlighting its potential as a therapeutic agent for inflammation-related conditions.

CD206 and dust particles are prognostic biomarkers of progressive fibrosing interstitial lung disease associated with air pollutant exposure

Current management strategies for progressive fibrosing interstitial lung disease (PF-ILD) and non-PF-ILD differ significantly, underscoring the need for early identification of PF-ILD patients. We analyzed the expression of macrophage markers and the number of dust particles (DP) in lung tissue, as well as complete blood count and blood chemistry tests to identify biomarkers of PF-ILD, and examined the effect of certain pollutants on these biomarkers. Lung biopsies were collected from 73 non-PF-ILD patients and 36 PF-ILD patients. DP were quantified in alveolar wall cells (DP-aw) and desquamated epithelial cells (DP-desq) using polarizing light microscopy. Expression of CD206, transforming growth factor β1 (TGF-β1), connective tissue growth factor (CTGF), C-X-C motif ligand 13 (CXCL13), fibroblast growth factor 2 (FGF-2), tumor necrosis factor α (TNFα), and interleukin 1β (IL-1β) was assessed in lung tissue by immunohistochemistry. The numbers of DP-desq, pulmonary expression of CXCL13, IL-1β and CD206 were higher in ILD patients resided for ≥ 15 days per year in places with 24-hour ambient PM10 level of ≥ 50 µg/m3 compared with ILD patients exposed for < 15 days per year to the similar PM10 concentration. Additionally, CXCL13 expression in lung tissue was higher in smoking ILD patients than in non-smoking ILD patients. Compared with non-PF-ILD patients, PF-ILD patients exhibited higher numbers of DP-aw and DP-desq, as well as increased expression of CD206, CXCL13, IL-1β, TGF-β1, and CTGF in lung tissue. Elevated blood neutrophil-to-lymphocyte (NLR) and platelet-to-lymphocyte ratios were also observed in PF-ILD patients. These biomarkers were found to be independent predictors of PF-ILD. A regression logistic model incorporating NLR, CD206, and DP-desq predicted PF-ILD with an AUC of 0.847, sensitivity of 84.6%, and specificity of 83.3%. Our findings may be useful in predicting PF-ILD and highlight the need for reducing pollutant emission.

Tumor Microenvironment Dynamics of Triple-Negative Breast Cancer Under Radiation Therapy

Triple-negative breast cancer (TNBC) is an aggressive subtype of breast cancer characterized by the absence of estrogen receptors (ER), progesterone receptors (PR), and HER2 expression. While TNBC is relatively less common, accounting for only 10-15% of initial breast cancer diagnosis, due to its aggressive nature, it carries a worse prognosis in comparison to its hormone receptor-positive counterparts. Despite significant advancements in the screening, diagnosis, and treatment of breast cancer, TNBC remains an important public health burden. Following treatment with chemotherapy, surgery, and radiation, over 40% of TNBC patients experience relapse within 3 years and achieve the least benefit from post-mastectomy radiation. The tumor microenvironment environment (TME) is pivotal in TNBC initiation, progression, immune evasion, treatment resistance, and tumor prognosis. TME is a complex network that consists of immune cells, non-immune cells, and soluble factors located in the region adjacent to the tumor that modulates the therapeutic response differentially between hormone receptor-positive breast cancer and TNBC. While the mechanisms underlying the radiation resistance of TNBC remain unclear, the immunosuppressive TME of TNBC has been implicated in chemotherapeutic resistance. Radiation therapy (RT) is known to alter the TME; however, immune changes elicited by radiation are poorly characterized to date, and whether these immune changes contribute to radiation resistance remains unknown. This review delves into the distinct characteristics of the TNBC TME, explores how RT influences TME dynamics, and examines mechanisms underlying tumor radiosensitization, radioresistance, and immune responses.

Advanced surface modification techniques for titanium implants: a review of osteogenic and antibacterial strategies

Titanium (Ti) implants are widely used in orthopedic and dental applications due to their excellent mechanical strength, corrosion resistance, and biocompatibility. However, their limited osteointegration and susceptibility to bacterial infections remain major clinical challenges. Recent advancements in surface modification techniques have significantly improved the osteogenic and antibacterial properties of Ti implants. This review summarizes key strategies, including ion doping, hydroxyapatite (HAp) coatings, nanostructured surfaces, and graphene-based modifications. Zinc (Zn)-doped coatings increase osteoblast proliferation by 25%, enhance cell adhesion by 40%, and inhibit Staphylococcus aureus by 24%. Magnesium (Mg)-doped Ti surfaces enhance osteoblast differentiation, with 38% increased alkaline phosphatase (ALP) activity and a 4.5-fold increase in cell proliferation. Copper (Cu)-doped coatings achieve 99.45% antibacterial efficacy against S. aureus and 98.65% against Escherichia coli (E. coli). Zn-substituted HAp promotes mineralized nodule formation by 4.5-fold and exhibits 16.25% bacterial inhibition against E. coli. Graphene-based coatings stimulate bone marrow stem cells (BMSCs) and provide light-responsive surface potentials for enhanced osteogenesis. Despite these advancements, challenges remain in optimizing ion release kinetics and long-term stability. Future research should focus on multi-functional coatings that integrate osteogenic, antibacterial, and immunomodulatory properties to enhance clinical performance and patient outcomes.

Guardians of the Lung: The Multifaceted Roles of Macrophages in Cancer and Infectious Disease

The lung as an organ that is fully exposed to the external environment for extended periods, comes into contact with numerous inhaled microorganisms. Lung macrophages are crucial for maintaining lung immunity and operate primarily through signaling pathways such as toll-like receptor 4 and nuclear factor-κB pathways. These macrophages constitute a diverse population with significant plasticity, exhibiting different phenotypes and functions on the basis of their origin, tissue residence, and environmental factors. During lung homeostasis, they are involved in the clearance of inhaled particles, cellular remnants, and even participate in metabolic processes. In disease states, lung macrophages transition from the inflammatory M1 phenotype to the anti-inflammatory M2 phenotype. These distinct phenotypes have varying transcriptional profiles and serve different functions, from combating pathogens to repairing inflammation-induced damage. However, macrophages can also exacerbate lung injury during prolonged inflammation or exposure to antigens. In this review, we delve into the diverse roles of pulmonary macrophages the realms in homeostasis, pneumonia, tuberculosis, and lung tumors.

Morphine's role in macrophage polarization: Exploring M1 and M2 dynamics and disease susceptibility

Morphine is a globally prevalent substance of misuse, renowned for its immunosuppressive effects mediated through opioid receptors expressed on immune cells. Macrophages are crucial antigen-presenting cells that fulfill diverse roles, such as antigen presentation, phagocytosis, wound healing, and disease protection. They are typically classified based on their activation states: M1 (proinflammatory), M2 (anti-inflammatory), and M0 (resting). Morphine significantly modulates immune responses and neuroinflammation, further complicating the landscape of opioid dependency and disease susceptibility. The association of macrophages under the influence of morphine needs to be understood under various diseased conditions. Several studies have been focused on investigating the impact of morphine on macrophage function and its implications in infectious diseases and brain-associated diseases. To light this subject, we have discussed recent advancements in understanding the influences between morphine, macrophage function, polarization, infection, brain tumors, and drug dependency. This article explores the complex relationship between morphine, macrophages, and related pathologies. Consequently, discussing deeper insights into these dynamics could guide effective treatments for substance abuse disorders.

A human histidyl-tRNA synthetase splice variant therapeutic targets NRP2 to resolve lung inflammation and fibrosis

Interstitial lung disease (ILD) consists of a group of immune-mediated disorders that can cause inflammation and progressive fibrosis of the lungs, representing an area of unmet medical need given the lack of disease-modifying therapies and toxicities associated with current treatment options. Tissue-specific splice variants (SVs) of human aminoacyl-tRNA synthetases (aaRSs) are catalytic nulls thought to confer regulatory functions. One example from human histidyl-tRNA synthetase (HARS), termed HARSWHEP because the splicing event resulted in a protein encompassing the WHEP-TRS domain of HARS (a structurally conserved domain found in multiple aaRSs), is enriched in human lung and up-regulated by inflammatory cytokines in lung and immune cells. Structural analysis of HARSWHEP confirmed a well-organized helix-turn-helix motif. This motif bound specifically and selectively to neuropilin-2 (NRP2), a receptor expressed by myeloid cells in active sites of inflammation, to inhibit expression of proinflammatory receptors and cytokines and to down-regulate inflammatory pathways in primary human macrophages. In animal models of lung injury and ILD, including bleomycin treatment, silicosis, sarcoidosis, chronic hypersensitivity pneumonitis, systemic sclerosis, and rheumatoid arthritis-ILD, HARSWHEP reduced lung inflammation, immune cell infiltration, and fibrosis. In patients with sarcoidosis, efzofitimod treatment resulted in down-regulation of gene expression for inflammatory pathways in peripheral immune cells and stabilization of inflammatory biomarkers in serum after steroid tapering. We demonstrate the immunomodulatory activity of HARSWHEP and present preclinical data supporting ongoing clinical development of the biologic efzofitimod based on HARSWHEP in ILD.

The Immune Environment in Colorectal Adenoma: A Systematic Review

Background/Objectives: Research on colorectal adenoma is significantly less comprehensive compared to studies on colorectal carcinoma. Although colorectal adenoma is a precursor of the majority of sporadic colorectal cancers, not all adenomas develop into carcinomas. The complex interaction of immune responses in the premalignant tumor microenvironment might be a factor for that. Methods: In this systematic review, we aim to provide a thorough analysis of the current research examining the immune infiltration patterns in sporadic colorectal adenoma tissues in the context of immune cell-based, cytokine-based, and other immunological factor-related changes along the conventional adenoma-carcinoma sequence. The articles included in the review extend up to December 2024 in PubMed and Web of Science databases. Results: Most included studies have shown significant differences in immune cell counts, densities, and cytokine expression levels associated with premalignant colorectal lesions (and/or colorectal cancer). No consensus on the immune-related tendencies concerning CD4+T cells and CD8+T cells was reached. Decreasing expression of mDCs and plasma and naïve B cells were detected along the ACS. The increased density of tissue eosinophils in the adenoma tissue dramatically diminishes after the transition to carcinoma. As the adenoma progresses, the increasing expression of IL-1α, IL-4, IL-6, IL-8, IL-10, IL-17A, IL-21, IL-23, IL-33, and TGF-β and decreasing levels of IL-12A, IL-18, IFN-γ, and TNFα cytokines in the invasive carcinoma stage is being detected. The over-expression of COX-2, PD-1/PD-L1, CTLA-4, and ICOS/ICOSLG in the colorectal adenomatous and cancerous tissues was also observed. Conclusions: Further studies are needed for a better understanding of the whole picture of colorectal adenoma-associated immunity and its impact on precancerous lesion's potential to progress.

The Role of Inflammation in the Pathogenesis of Comorbidity of Chronic Obstructive Pulmonary Disease and Pulmonary Tuberculosis

The comorbid course of chronic obstructive pulmonary disease (COPD) and pulmonary tuberculosis is an important medical and social problem. Both diseases, although having different etiologies, have many overlapping relationships that mutually influence their course and prognosis. The aim of the current review is to discuss the role of different immune mechanisms underlying inflammation in COPD and pulmonary tuberculosis. These mechanisms are known to involve both the innate and adaptive immune system, including various cellular and intercellular interactions. There is growing evidence that immune mechanisms involved in the pathogenesis of both COPD and tuberculosis may jointly contribute to the tuberculosis-associated obstructive pulmonary disease (TOPD) phenotype. Several studies have reported prior tuberculosis as a risk factor for COPD. Therefore, the study of the mechanisms that link COPD and tuberculosis is of considerable clinical interest.

Development of Anti-Inflammatory Agents Utilizing DC-SIGN Mediated IL-10 Secretion in Autoimmune and Immune-Mediated Disorders: Bridging Veterinary and Human Health

DC-SIGN (dendritic cell-specific intercellular adhesion molecule-3-grabbing non-integrin) is a C-type lectin receptor expressed on dendritic cells and M2 macrophages, playing a key role in immune regulation and pathogen recognition. Its ability to mediate anti-inflammatory effects by interacting with specific ligands triggers pathways that suppress pro-inflammatory responses and promote tissue repair, making it a potential therapeutic target for inflammatory and autoimmune diseases. DC-SIGN homologs in various animal species share structural similarities and perform comparable immune functions, offering valuable insights into its broader application across species. By recognizing carbohydrate ligands on pathogens, DC-SIGN facilitates immune modulation, which can be harnessed for developing therapies aimed at controlling inflammation. In veterinary medicine, autoimmune and inflammatory diseases, such as rheumatoid arthritis and inflammatory bowel disease, represent significant challenges, and the anti-inflammatory properties of DC-SIGN could provide new therapeutic options to improve disease management and enhance animal health. Future investigations should focus on the structural and functional analysis of DC-SIGN homologs in various species, as well as the development of preclinical models to translate these findings into clinical interventions bridging veterinary and human health.

Mesoporous polymeric nanoparticles for effective treatment of inflammatory diseases: an in vivo study

Acute inflammatory diseases require suitable medicine over the existing therapeutics. In this line, the present work is focused on developing polymeric nanomedicine for the treatment of inflammatory disorders. Herein, cell viable nanoparticles (GlyNPs) of size 180-250 nm in diameter and pore size of 4-5 nm in diameter, based on glycine and acryloyl chloride, have been developed and proved to be a potential anti-inflammatory agent without using any conventional drugs. These particles exhibit colloidal stability (with a zeta potential of -35.6 mV). A network pharmacology-based computational study has been executed on 9076 genes and proteins responsible for inflammatory diseases, out of which 10 are selected that have a major role in rheumatoid arthritis (RA). In silico docking study has been conducted to find out the targeted efficiency of the GlyNPs considering 10 inflammation-specific markers, namely IL-6, IL-1β, TNF-α, TLR-4, STAT-1, MAPK-8, MAPK-14, iNOS, NF-κβ and COX-2. The results revealed that the GlyNPs could be an excellent anti-inflammatory component similar to aspirin. The in vitro inflammation activity of these GlyNPs has also been checked on an inflammation model generated by LPS in RAW 264.7 macrophages. Then, the in vitro anti-inflammation efficiency has been checked with 10-150 μg mL-1 of GlyNP doses. The treatment efficiency has been checked on inflammation-responsible immune markers (NO level, NF-κβ, INF-γ, IL-6, IL-10, and TNF-α) and it was found that the GlyNPs are an excellent component in reducing inflammation. The in vivo therapeutic response of GlyNPs on the induced rheumatoid arthritis (RA) model has been evaluated by measuring the morphological, biochemical and immune-cytokine and interferon levels responsible for the inflammation, using a 2 g kg-1 dose (sample to weight of rat). The anti-inflammatory efficiency of GlyNPs without using additional drugs was found to be excellent. Thus, GlyNPs could be paramount for the potential treatment of various inflammatory diseases.

Burn inhalation injury and intubation with dexamethasone-eluting endotracheal tubes modulate local microbiome and alter airway inflammation

Background

Inhalation injuries, caused by exposure to extreme heat and chemical irritants, lead to complications with speaking, swallowing, and breathing. This study investigates the effects of thermal injury and endotracheal tube (ETT) placement on the airway microbiome and inflammatory response. A secondary aim is to assess the impact of localized dexamethasone delivery via a drug-eluting ETT to reduce laryngeal scarring.

Methods

Inhalation injury was developed in swine by administering heated air (150°C-160°C) under endoscopic visualization. Following injury, segments of regular or dexamethasone-loaded endotracheal tubes (ETTs) were placed in the injured airways for 3 or 7 days. Computed tomography (CT) scans were used to assess airway narrowing post-injury. Biofilm formation on the ETTs was investigated using micro-CT and microscopy. The airway microbiome was analyzed via 16S rRNA sequencing. Inflammatory markers were quantified using an immunoassay and macrophage populations in laryngeal tissue were assessed with CD86 and CD206 staining. Tracheal tissues were also histologically examined for epithelial thickness, collagen area, and mucin production.

Results

CT scans confirmed airway narrowing post-injury, particularly around ETT sites. Biofilm formation was more extensive on dexamethasone-coated ETTs at later timepoints. Beta diversity analysis revealed significant shifts in microbial composition related to ETT type (R2 = 0.04, p < 0.05) and duration of placement (R2 = 0.22, p < 0.05). Differential abundance analysis demonstrated significant positive log fold changes in genera such as Bergeriella, Peptostreptococcus, and Bacteriodes with thermal injury over time. Inflammatory markers IFN-γ, IL-4, and IL-1β were elevated in dexamethasone-ETT groups at 3 days, then decreased by 7 days. Macrophage markers CD86 and CD206 were significantly greater in dexamethasone groups compared to regular ETT groups at 7 days (p = 0.002 and p = 0.0213, respectively). Epithelial thickness was significantly greater with regular ETT placement compared to dexamethasone ETT placement in the burn-injured airway at 3 days (p = 0.027).

Conclusion

Thermal inhalation injury and ETT placement significantly impact airway inflammation, structural integrity, and microbiome composition. Dexamethasone-eluting ETTs, intended to reduce inflammation, increased biofilm formation and elevated cytokine levels, suggesting complex interactions between the drug coating and the host immune response. The airway microbiome shifted significantly with specific taxa thriving in the inflamed environment.

Time-resolved single-cell secretion analysis via microfluidics

Revealing how individual cells alter their secretions over time is crucial for understanding their responses to environmental changes. Key questions include: When do cells modify their functions and states? What transitions occur? Insights into the kinetic secretion trajectories of various cell types are essential for unraveling complex biological systems. This review highlights seven microfluidic technologies for time-resolved single-cell secretion analysis: 1. Microwell real-time electrical detection: uses microelectrodes for precise, cell-specific, real-time measurement of secreted molecules. 2. Microwell real-time optical detection: employs advanced optical systems for real-time, multiplexed monitoring of cellular secretions. 3. Microvalve real-time optical detection: dynamically analyzes secretions under controlled in situ stimuli, enabling detailed kinetic studies at the single-cell level. 4. Droplet real-time optical detection: provides superior throughput by generating droplets containing single cells and sensors for high-throughput screening. 5. Microwell time-barcoded optical detection: utilizes sequential barcoding techniques to facilitate scalable assays for tracking multiple secretions over time. 6. Microvalve time-barcoded optical detection: incorporates automated time-barcoding via micro-valves for robust and scalable analysis. 7. Microwell time-barcoded sequencing: captures and labels secretions for sequencing, enabling multidimensional analysis, though currently limited to a few time points and extended intervals. This review specifically addresses the challenges of achieving high-resolution timing measurements with short intervals while maintaining scalability for single-cell screening. Future advancements in microfluidic devices, integrating innovative barcoding technologies, advanced imaging technologies, artificial intelligence-powered decoding and analysis, and automations are anticipated to enable highly sensitive, scalable, high-throughput single-cell dynamic analysis. These developments hold great promise for deepening our understanding of biosystems by exploring single-cell timing responses on a larger scale.

A micro-lung chip with macrophages for targeted anti-fibrotic therapy

Idiopathic pulmonary fibrosis (IPF) is a lethal lung disease of unknown etiology. Macrophages are implicated in the fibrotic process, but exhibit remarkable plasticity in the activated immune environmentin vivo, presenting significant challenges as therapeutic targets. To explore the influence of macrophages on IPF and develop macrophage-targeted therapies, we engineered a micro-lung chip with a lung epithelium-interstitium tissue unit to establish a controlled immune environment containing only macrophages. We discovered that macrophages exacerbated inflammation and fibrosis by comparing microchips treated with bleomycin (BLM) in the presence and absence of macrophages. Based on the duration of BLM treatment, we established pathological models corresponding to inflammation and fibrosis stages. Transcriptome analysis revealed that activation of the PI3K-AKT signalling pathway facilitates the transition from inflammation to fibrosis. However, LY294002, a PI3K inhibitor, not only suppressed fibrosis and decreased the accumulation of M2 macrophages but also intensified the severity of inflammation. These findings suggest that macrophages play a pivotal role in the potential development at the tissue level. The micro-lung chip co-cultured with macrophages holds significant potential for exploring the pathological progression of IPF and elucidating the mechanisms of anti-fibrotic drugs.

Unravelling approaches to study macrophages: from classical to novel biophysical methodologies

Macrophages play crucial roles in immune responses and tissue homeostasis. Despite the fact that macrophages were described more than a century ago, they continue to be the cells of intensive interest. Advanced understanding of phenotypic diversity in macrophages holds great promise for development of cell-based therapeutic strategies. The introduction of innovative approaches in cell biology greatly enhances our ability to investigate the unique characteristics of macrophages. The review considers both classical methods to study macrophages and high-tech approaches, including single-cell sequencing, single-cell mass spectrometry, droplet microfluidics, scanning probe microscopy and atomic force spectroscopy. This review will be valuable both to specialists beginning their study of macrophages and to experienced scientists seeking to deepen their understanding of methods at the intersection of biological and physical sciences.

Role of innate immune cells in multiple sclerosis

Multiple sclerosis (MS) is a chronic autoimmune, inflammatory and neurodegenerative disease affecting the central nervous system (CNS). MS is associated with a complex interplay between neurodegenerative and inflammatory processes, mostly attributed to pathogenic T and B cells. However, a growing body of preclinical and clinical evidence indicates that innate immunity plays a crucial role in MS promotion and progression. Accordingly, preclinical and clinical studies targeting different innate immune cells to control MS are currently under study, highlighting the importance of innate immunity in this pathology. Here, we reviewed recent findings regarding the role played by innate immune cells in the pathogenesis of MS. Additionally, we discuss potential new treatments for MS based on targets against innate immune components.

Immunogenic Cell Death: the Key to Unlocking the Potential for Combined Radiation and Immunotherapy

Immunogenic cell death (ICD) enhances anti-tumor immunity by releasing tumor-associated antigens and activating the anti-tumor immune system response. However, its potential remains understudied in combination therapies. Here, we develop a mathematical model to quantify the role of ICD in optimizing the efficacy of combined radiotherapy (RT) and macrophage-based immunotherapy. Using preclinical murine data targeting the SIRP α -CD47 checkpoint, we show that RT alone induces minimal ICD, whereas disrupting the SIRP α -CD47 axis significantly enhances both phagocytosis and systemic immune activation. Our model predicts an optimal RT dose (6-8 Gy) for maximizing ICD, a dose-dependent abscopal effect, and a hierarchy of treatment efficacy, with SIRP α -knockout macrophages exhibiting the strongest tumoricidal activity. These findings provide a quantitative framework for designing more effective combination therapies, leveraging ICD to enhance immune checkpoint inhibition and radiotherapy synergy.

Polarized Tissue-Derived Macrophages Display Enhanced M2d Phenotype after Prolonged Stimulation with Adenosine A2A Receptor Agonist in the Presence of LPS

BACKGROUND

Macrophages (Mφ) are innate immune cells known for their different activation phenotypes, classically described as falling within two broad categories, M1 and M2. The latter were originally described as alternatively activated M2 cells to differentiate them from classically activated M1 cells. M2 cells were later classified into M2a (interleukin (IL)-4), M2b (immune complex), M2c (IL-10) and M2d (5-(N-ethylcarboxamido) adenosine (NECA) + lipopolysaccharide (LPS)) based on their inducing stimuli. Considering the established role of M2d/tumour-associated macrophage (TAM) cells within cancer initiation and proliferation, expanding on the knowledge of M2d characteristics can provide fundamental information for Mφ targeted immunotherapy. The precise characterization of M2d cells derived from tissues has not been described in detail.

METHODS

Our study focused on spleen-derived macrophages (SpM), which were also compared to bone marrow-derived macrophages (BMDMs).

RESULTS

By investigating different conditions for M2d-specific stimulation and employing various assays including functional tests, we show how Mφ M2d (NECA + LPS) polarization can be affected by prolonged culture conditions to induce a phenotype that was clearly different from M2a cells.

CONCLUSION

This work offers new insights into the properties of primary M2d Mφ following extended stimulation with LPS and NECA.

Placental malaria infection is associated with downregulation of STAT-6 and ANG-1 in decidual macrophages

Introduction

Macrophages play a crucial immunological role in maintaining pregnancy. Placental malaria infection may cause dysfunction in decidual macrophages which then culminates in the associated pregnancy complications. Here, we determined the influence of placental malaria on decidual macrophages, by assessing their distribution based on their unique phenotypes, and examining their expression levels of transcription factors as well as angiogenic factors, in placentas from women living in a malaria-endemic area.

Methods

We compared these macrophage parameters in placentas from malaria infected women to those from the uninfected women. Placentas were collected upon delivery and malaria infection determined by histology together with PCR from dry blood spots obtained from placental blood. Following enzymatic dissociation of placental tissue, immune cells were enriched from the total population of placental cells by density centrifugation. Macrophage phenotypic characteristics were then analyzed from the placental immune cells by flow cytometry. The expression of surface markers CD68, CD80, CD86, CD163, CD206, and CD209, was used to delineate the macrophage populations. For gene expression profiling, macrophages were isolated from the placental immune cells and the expression level of transcription factors STAT-1, IRF-5, STAT-6, c-Maf and angiogenic factors ANG-1, ANG-2 and VEGF determined by qPCR.

Results and Discussion

We found no difference in the total macrophage populations and M1 and M2 macrophage profiles between uninfected and infected placentas, however, M2 macrophages were significantly higher compared to their M1 counterparts regardless of infection status. Notably, the gene expression levels of the transcription factor STAT-6 and angiogenic factor ANG-1 were significantly lower in infected placentas. These findings provide a basis for further understanding of the role of placental macrophages in placental malaria pathogenesis. Analysis of the functional consequences of these observations is needed to determine if these factors can be explored to reprogram macrophage polarization to desired state.

SPP1-mediated M2 macrophage polarization shapes the tumor microenvironment and enhances prognosis and immunotherapy guidance in nasopharyngeal carcinoma

Secreted phosphoprotein 1 (SPP1) shows carcinogenic potential in multiple cancers, yet its role in nasopharyngeal carcinoma (NPC) remains elusive. Leveraging transcriptomic data sourced from an NPC cohort at Fujian Cancer Hospital, alongside datasets from the Gene Expression Omnibus cohort and a single-cell RNA sequencing dataset, this investigation explored the role of SPP1 in tumor progression and the tumor microenvironment of NPC. A co-culture system involving tumor cells and macrophages was established to elucidate the relationship between SPP1 and tumor-associated macrophages in NPC. Subsequently, we established an SPP1-driven M2 macrophage signature using a machine-learning-based framework to predict patient prognosis. The results of our analysis indicated that SPP1 is associated with an elevated risk of disease progression and poor prognosis in NPC. Single-cell analysis demonstrated that SPP1 is a pivotal gene in the polarization of M2 macrophages within the tumor microenvironment. In vitro experiments demonstrated that NPC-derived SPP1 has the potential to activate the CD44/JAK2/STAT3 signaling pathway, promoting macrophage recruitment and polarization of the M2 subtype. Furthermore, we established a comprehensive SPP1-related M2 macrophage signature that can predict the prognosis and immune characteristics of patients with NPC. Our findings offer new insights into the role of SPP1 in the tumor microenvironment of NPC, and provide a novel SPP1-driven M2 macrophage signature with the potential to serve as a valuable tool for prognosis prediction and personalized therapy in NPC.

The tryptophan metabolite kynurenic acid ameliorates septic colonic injury through activation of the PPARγ signaling pathway

Sepsis is the leading cause of death among critically ill patients in clinical practice, making it urgent to reduce its incidence and mortality rates. In sepsis, macrophage dysfunction often worsens and complicates the condition. M1 and M2 macrophages, two distinct types, contribute to pro-inflammatory and anti-inflammatory effects, respectively. An imbalance between them is a major cause of sepsis. The aim of this study was to explore the potential of a differential metabolite between M1 and M2 macrophages in mitigating septic colonic injury via multiomics in combination with clinical data and animal experiments. Using nontargeted metabolomics analysis, we found that Kynurenic acid (KYNA), a metabolite of tryptophan metabolism, was significantly upregulated in the supernatant of M2 macrophages. Furthermore, we discovered that the level of KYNA was significantly decreased in sepsis in both human and mouse serum and was negatively correlated with inflammatory factor levels. In vivo experiments demonstrated that KYNA can effectively alleviate septic colon injury and reduce inflammatory factor levels in mice, indicating that KYNA plays a very important protective role in sepsis. Mechanistically, KYNA promotes the transition of M1 macrophages to M2 macrophages by inhibiting the NF-κB signaling pathway and alleviates septic colonic injury through the PPARγ/NF-κB axis. This article reveals that KYNA, a differentially abundant metabolite between M1 and M2 macrophages, can become a new strategy for alleviating septic colon injury.

Aerobic exercise decreases the number and transcript expression of inflammatory M1 macrophages and CD8+ T cells in the epicardial adipose tissue of female pigs

Background

Epicardial adipose tissue (EAT) regulates coronary artery function via lipid metabolism and immune cell recruitment. Increased EAT is a risk factor for coronary artery disease (CAD), but aerobic exercise mitigates CAD. The effect of aerobic exercise on immune cells in EAT is unknown. We hypothesized that aerobic exercise creates an anti-inflammatory environment characterized by increased M2 macrophages and up-regulation of anti-inflammatory cytokine transcripts in EAT.

Methods

Female Yucatan pigs (n=7) were allocated to sedentary or exercised groups. To mimic CAD, a coronary artery was chronically occluded or remained non-occluded. EAT samples were processed for bulk and single nuclei transcriptomic sequencing.

Results

Sub-clustering identified immune, endothelial, smooth muscle, adipocytes, adipocyte progenitor cells (APSCs), and neuronal cells, with adipocytes and APSCs being dominant. Non-occluded sedentary EAT had the largest percentage of M1 macrophages and CD8+ T cells. Irrespective of occlusion, sedentary EAT had the largest fraction of cells expressing genes in the tumor necrosis factor (TNF) superfamily. Irrespective of occlusion, exercise upregulated peroxisome proliferator-activated receptor (PPAR) gamma (G) expression and enriched PPAR signaling pathways in adipocytes, macrophages, and T cells. However, PPARG expression was lowest in CD8+ T cells from non-occluded exercised EAT. The greatest number of significant cell-cell communications between adipocytes and immune cells via growth factors and adhesion molecules occurred in occluded sedentary EAT.

Conclusion

Aerobic exercise mitigates the proinflammatory nature of EAT in CAD via modulation of immune cell subpopulations, decreased TNF superfamily and increased PPARG gene expression, and decreased growth factor communication between adipocytes and immune cells.

Tumor-Associated Macrophages Nano-Reprogrammers Induce "Gear Effect" to Empower Glioblastoma Immunotherapy

Glioblastoma (GBM), the most malignant brain tumor with high prevalence, remains highly resistant to the existing immunotherapies due to the significant immunosuppression within tumor microenvironment (TME), predominantly manipulated by M2-phenotypic tumor-associated macrophages (M2-TAMs). Here in this work, an M2-TAMs targeted nano-reprogrammers, MG5-S-IMDQ, is established by decorating the mannose molecule as the targeting moiety as well as the toll-like receptor (TLR) 7/8 agonist, imidazoquinoline (IMDQ) on the dendrimeric nanoscaffold. MG5-S-IMDQ demonstrated an excellent capacity of penetrating the blood-brain barrier (BBB) as well as selectively targeting M2-TAMs in the GBM microenvironment, leading to a phenotype transformation and function restoration of TAMs shown as heightened phagocytic activity toward tumor cells, enhanced cytotoxic effects, and improved tumor antigen cross-presentation capability. In the meantime, by induction of a function-oriented "gear effect", MG5-S-IMDQ treatment extended its impact systemically by enhancing the infiltration of type I conventional dendritic cells (cDC1s) into the tumor sites and bolstering adaptive immune responses. In sum, by precisely working on M2-TAMs as a unique target in tumor situ, the nano-reprogrammers successfully established a robust immune network that worked synergistically to combat tumors. This facile nanoplatform-based immunomodulatory strategy, serving as a powerful and convenient immune monotherapy or as a complementary treatment alongside other therapies like surgery, provided deep insights for advancing translational study in GBM.

Immune mechanisms and shared immune targets in neurodegenerative diseases

The immune system plays a major part in neurodegenerative diseases. In some, such as multiple sclerosis, it is the primary driver of the disease. In others, such as Alzheimer disease, amyotrophic lateral sclerosis and Parkinson disease, it has an amplifying role. Immunotherapeutic approaches that target the adaptive and innate immune systems are being explored for the treatment of almost all neurological diseases, and the targets and approaches are often common across diseases. Microglia are the primary immune cells in the brain that contribute to disease pathogenesis, and are consequently a common immune target for therapy. Other therapeutic approaches target components of the peripheral immune system, such as regulatory T cells and monocytes, which in turn act within the CNS. This Review considers in detail how microglia, monocytes and T cells contribute to the pathogenesis of multiple sclerosis, Alzheimer disease, amyotrophic lateral sclerosis and Parkinson disease, and their potential as shared therapeutic targets across these diseases. The microbiome is also highlighted as an emerging therapeutic target that indirectly modulates the immune system. Therapeutic approaches being developed to target immune function in neurodegenerative diseases are discussed, highlighting how immune-based approaches developed to treat one disease could be applicable to multiple other neurological diseases.

Bacteriophage derived dsRNA induces polarized activation of alveolar macrophages from Balb/c and C57Bl/6 mice in vitro in sex- and age-dependent manner

Bacteriophage-derived dsRNA (bp-dsRNA), also known as Larifan, is a poly-functional and wide-spectrum antiviral medication with potent interferonogenic activity. In the lungs of golden Syrian hamsters infected with SARS-CoV-2, Larifan substantially reduces viral load and decreases infection-induced pathological lesion severity. Alveolar macrophages (AM) are key sentinel cells in the lung, which play an important role in antiviral innate immune responses and, at the same time, can trigger infection-associated hyper-inflammatory response. This study revealed that treatment with bp-dsRNA (Larifan) in vitro modulates the functional profile of AM from intact Balb/c and C57Bl/6 mice. The pattern of the drug response depends on the animal strain, age and sex. AM from Balb/c mice generated a weaker response to the preparation as compared to cells from C57Bl/6 mice. Most emphatic responses to the treatment with bf-dsRNA (Larifan) were registered in AM from old males of both BALB/c and C57BL/6 strains with the strongest in the latter. AM from old C57BL/6 females were less likely to be influenced by the preparation. In most cases, exposure to bf-dsRNA (Larifan) increased AM phagocytic activity and was more often accompanied by the stimulation of intracellular reactive oxygen species generation, than by its decrease. In most animal groups, treatment with bf-dsRNA (Larifan) did not affect significantly CD206 expression and down-regulated CD80 expression in AM. Taken together, our findings suggest that bf-dsRNA (Larifan) not so much stimulates the bivalent phenotype of AM, as restrains their hyper-inflammatory responses through the control of antigen-presentation while preserving functional signatures typical of patrolling tissue-resident macrophages.

Inflammatory signalling during the perinatal period: Implications for short- and long-term disease risk

During pregnancy and the postpartum, there are dynamic fluctuations in steroid and peptide hormone levels as well as inflammatory signalling. These changes are required for a healthy pregnancy and can persist well beyond the postpartum. Many of the same hormone and inflammatory signalling changes observed during the perinatal period also play a role in symptoms related to autoimmune disorders, psychiatric disorders, and perhaps neurodegenerative disease later in life. In this review, we outline hormonal and immunological shifts linked to pregnancy and the postpartum and discuss the possible role of these shifts in increasing psychiatric, neurodegenerative disease risk and autoimmune symptoms during and following pregnancy. Furthermore, we discuss how key variables such as the number of births (parity) and sex of the fetus can influence inflammatory signalling, and possibly future disease risk, but are not often studied. We conclude by discussing the importance of studying female experiences such as pregnancy and parenting on physiology and disease.

Diverse Functions of Macrophages in Obesity and Metabolic Dysfunction-Associated Steatotic Liver Disease: Bridging Inflammation and Metabolism

Macrophages play crucial roles in immune response and tissue homeostasis, with their functions becoming increasingly complex in obesity-mediated metabolic disorders. This review explores the extensive range of macrophage activities within adipose and liver tissues, emphasizing their contribution to the pathogenesis and progression of obesity and its related metabolic dysfunction-associated steatotic liver disease (MASLD). In the context of obesity, macrophages respond adaptively to lipid overloads and inflammatory cues in adipose tissue, profoundly influencing insulin resistance and metabolic homeostasis. Concurrently, their role in the liver extends to moderating inflammation and orchestrating fibrotic responses, integral to the development of MASLD. Highlighting the spectrum of macrophage phenotypes across these metabolic landscapes, we summarize their diverse roles in linking inflammatory processes with metabolic functions. This review advocates for a deeper understanding of macrophage subsets in metabolic tissues, proposing targeted research to harness their therapeutic potential in mitigating MASLD and other metabolic disorders.

Macrophage metabolic reprogramming ameliorates diabetes-induced microvascular dysfunction

Macrophages play an important role in the development of vascular diseases, with their homeostasis closely linked to metabolic reprogramming. This study aims to explore the role of circular RNA-mediated epigenetic remodeling in maintaining macrophage homeostasis during diabetes-induced microvascular dysfunction. We identified a circular RNA, circRNA-sperm antigen with calponin homology and coiled-coil domains 1 (cSPECC1), which is significantly up-regulated in diabetic retinas and in macrophages under diabetic stress. cSPECC1 knockdown in macrophages attenuates M1 macrophage polarization and disrupts macrophage-endothelial crosstalk in vitro. cSPECC1 knockdown in macrophages mitigates diabetes-induced retinal inflammation and ameliorates retinal vascular dysfunction. Mechanistically, cSPECC1 regulates GPX2 expression by recruiting eIF4A3, enhancing GPX2 mRNA stability and altering arachidonic acid metabolism. The metabolic intermediate 12-HETE has emerged as a key mediator, regulating both macrophage homeostasis and the crosstalk between macrophages and endothelial cells. Exogenous 12-HETE supplementation interrupts the anti-angiogenic effects of cSPECC1 knockdown. Collectively, circSPECC1 emerges as a novel regulator of macrophage-mediated vascular integrity and inflammation. Targeting the metabolic reprogramming of macrophages presents a promising therapeutic strategy for mitigating diabetes-induced vascular dysfunction.

Chimeric Antigen Receptor Cell Therapy: Empowering Treatment Strategies for Solid Tumors

Chimeric antigen receptor-T (CAR-T) cell therapy has demonstrated impressive efficacy in the treatment of blood cancers; however, its effectiveness against solid tumors has been significantly limited. The differences arise from a range of difficulties linked to solid tumors, including an unfriendly tumor microenvironment, variability within the tumors, and barriers to CAR-T cell infiltration and longevity at the tumor location. Research shows that the reasons for the decreased effectiveness of CAR-T cells in treating solid tumors are not well understood, highlighting the ongoing need for strategies to address these challenges. Current strategies frequently incorporate combinatorial therapies designed to boost CAR-T cell functionality and enhance their capacity to effectively target solid tumors. However, these strategies remain in the testing phase and necessitate additional validation to assess their potential benefits. CAR-NK (natural killer), CAR-iNKT (invariant natural killer T), and CAR-M (macrophage) cell therapies are emerging as promising strategies for the treatment of solid tumors. Recent studies highlight the construction and optimization of CAR-NK cells, emphasizing their potential to overcome the unique challenges posed by the solid tumor microenvironment, such as hypoxia and metabolic barriers. This review focuses on CAR cell therapy in the treatment of solid tumors.

Human Primary Monocytes as a Model for in vitro Immunotoxicity Testing: Evaluation of the Regulatory Properties of TiO2 Nanoparticles

Introduction

A critical step preceding the potential biomedical application of nanoparticles is the evaluation of their immunomodulatory effects. Such nanoparticles are expected to enter the bloodstream where they can be recognized and processed by circulating monocytes. Despite the required biocompatibility, this interaction can affect intracellular homeostasis and modulate physiological functions, particularly inflammation. This study focuses on titanium dioxide (TiO2) as an example of relatively low cytotoxic nanoparticles with potential biomedical use and aims to evaluate their possible modulatory effects on the inflammasome-based response in human primary monocytes.

Methods

Monocyte viability, phenotypic changes, and cytokine production were determined after exposure to TiO2 (diameter, 25 nm; P25) alone. In the case of the modulatory effects, we focused on NLRP3 activation. The production of IL-1β and IL-10 was evaluated after (a) simultaneous activation of monocytes with bacterial stimuli muramyl dipeptide (MDP), or lipopolysaccharide (LPS), and TiO2 (co-exposure model), (b) prior activation with TiO2 alone and subsequent exposure to bacterial stimuli MDP or LPS. The differentiation of TiO2-treated monocytes into macrophages and their polarization were also assessed.

Results

The selected TiO2 concentration range (30-120 µg/mL) did not induce any significant cytotoxic effects. The highest dose of TiO2 promoted monocyte survival and differentiation into macrophages, with the M2 subset being the most prevalent. Nanoparticles alone did not induce substantial production of inflammatory cytokines IL-1β, IL-6, or TNF-α. The immunomodulatory effect on NLRP3 depended on the type of costimulant used. While co-exposure of monocytes to MDP and TiO2 boosted NLRP3 activity, co-exposure to LPS and TiO2 inhibited NLRP3 by enhancing IL-10 release. The inhibitory effect of TiO2 on NLRP3 based on the promotion of IL-10 was confirmed in a post-exposure model for both costimulants.

Conclusion

This study confirmed a non-negligible modulatory effect on primary monocytes in their inflammasome-based response and differentiation ability.

Systematic review of innate immune responses against Mycobacterium tuberculosis complex infection in animal models

Background

Mycobacterium tuberculosis (Mtb) complex (MTBC) includes ten species that affect mammals and pose a significant global health concern. Upon infection, Mtb induces various stages in the host, including early bacterial elimination, which may or may not involve memory responses. Deciphering the role of innate immune responses during MTBC infection is crucial for understanding disease progression or protection. Over the past decade, there has been growing interest in the innate immune response to Mtb, with new preclinical models emerging.

Methods

We conducted a systematic review following PRISMA guidelines, focused on innate immune mediators linked to protection or disease progression in animal models of MTBC infection. We searched two databases: National Library of Medicine and Web of Science. Two researchers independently extracted data based on specific inclusion and exclusion criteria.

Results

Eighty-three articles were reviewed. Results were categorized in four groups: MTBC species, animal models, soluble factors and innate pathways, and other molecules (metabolites and drugs). Mtb and M. bovis were the only species studied. P2X7R receptor's role in disease progression and higher macrophage recruitment were observed differentially after infection with hypervirulent Mtb strains. Mice and non-human primates (NHPs) were the most used mammals, with emerging models like Galleria mellonella and planarians also studied. NHPs provided insights into age-dependent immunity and markers for active tuberculosis (ATB). Key innate immune factors/pathways identified included TNF-α, neutrophil recruitment, ROS/RNS responses, autophagy, inflammasomes, and antimicrobial peptides, with homologous proteins identified in insects. Metabolites like vitamin B5 and prostaglandin E2 were associated with protection. Immunomodulatory drugs targeting autophagy and other mechanisms were studied, exhibiting their potential as therapeutic alternatives.

Conclusion

Simpler, physiologically relevant, and ethically sound models, such as G. mellonella, are needed for studying innate responses in MTBC infection. While insects lack adaptive immunity, they could provide insights into "pure" innate immune responses. The dissection of "pure," "sustained" (later than 7 days post-infection), and trained innate immunity presents additional challenges that require high-resolution temporospatial analytical methods. Identifying early innate immune mediators and targetable pathways in the blood and affected tissues could identify biomarkers for immunization efficiency, disease progression, and potential synergistic therapies for ATB.

Innate Immune Memory is Stimulus Specific

Innate immune memory (also termed trained immunity) is defined in part by its ability to cross-protect against heterologous pathogens, and can be generated by many different stimuli, suggesting a "universal" trained state. However, different stimuli could form distinct memories, leading to stimulus-specific trained responses. Here, we use primary human monocyte-derived macrophages to demonstrate phenotypic and epigenetic stimulus specificity of innate immune memory six days after initial exposure. Quantification of cytokine production with single-molecule RNA imaging demonstrates stimulus-specific patterns of response to restimulation at the single cell level. Differential licensing of inflammatory transcription factors is associated with encoding of specificities in chromatin. Trained cells show stronger responses to secondary stimuli that are more similar to the initial stimulus they experienced, suggesting a functional role for these stimulus-specific memories. Rather than activating a universal training state, our findings demonstrate that different stimuli impart specific memories that generate distinct training phenotypes in macrophages.

Bee Pollen Phytochemicals and Nutrients as Unequaled Pool of Epigenetic Regulators: Implications for Age-Related Diseases

Bee pollen is characterized by an exceptional diversity and abundance of micronutrients and bioactive phytochemicals. This richness remains very sparsely investigated, but accumulating evidence strongly supports a promising future for bee pollen in human nutrition and medicine. Epigenetic regulation is among the most compelling biomedical topics that remain completely untapped in bee pollen and bee derivative research. In our current research, we identified numerous ubiquitous compounds that are consistently present in this matrix, regardless of its botanical and geographical origins, and that have been well studied and documented as epigenetic regulators in recent years. Given the relative newness of both bee pollen biomedical research and epigenetic studies within nutritional, pharmaceutical, and medical sciences, this review aims to bridge these valuable fields and advance related experimental investigations. To the best of our knowledge, this is the first work that has aimed to comprehensively investigate the epigenetic modulatory potential of bee pollen compounds. Our findings have also unveiled several intriguing phenomena, such as a dual effect of the same compound depending on the cellular context or the effect of some compounds on the cross-generational heritability of epigenetic traits. Although experimental studies of epigenetic regulation by bee pollen as a whole or by its extract are still lacking, our current study clearly indicates that this research avenue is very promising and worth further investigations. We hope that our current work constitutes a foundational cornerstone of future investigations for this avenue of research.

Serotonin receptor 5-HT7 modulates inflammatory-associated functions of macrophages

The hormone and neurotransmitter serotonin regulates numerous physiological functions within the central nervous system and in the periphery upon binding to specific receptors. In the periphery, the serotonin receptor 7 (5-HT7R) is expressed on different immune cells including monocytes and macrophages. To investigate the impact of 5-HT7R-mediated signaling on macrophage properties, we used human THP-1 cells and differentiated them into pro-inflammatory M1- and anti-inflammatory M2-like macrophages. Pharmacological 5-HT7R activation with the specific agonist LP-211 especially modulates morphology of M1-like macrophages by increasing the number of rounded cells. Furthermore, 5-HT7R stimulation results in significantly reduced phagocytic and migratory ability of M1-like macrophages. Noteworthy, LP-211 treatment leads to changes in secretory properties of all macrophage types with the highest effects obtained for M0- and M2c-like macrophages. Finally, the importance of 5-HT7R for regulation of phagocytosis was confirmed in human primary CD14+ cells. These results indicate that 5-HT7R activation selectively impairs basic functions of macrophages and might thus be a new access point for the modulation of macrophage responses in the future treatment of inflammatory diseases.

Inhibition of MEK1/2 Signaling Pathway Limits M2 Macrophage Polarization and Interferes in the Dental Socket Repair Process in Mice

Dental socket repair theoretically involves a constructive inflammatory immune response, which evolves from an initial M1 prevalence to a subsequent M2 dominance. In this scenario, the MEK1/2 signaling pathway is allegedly involved in M2 polarization. This study aimed to evaluate the impact of MEK1/2 pharmacological inhibition in the local host response and repair outcome. C57Bl/6-WT 8-week-old male mice were submitted to the extraction of the right upper incisor and treated (or not, control group) with MEK1/2 inhibitor PD0325901 (10 mg/kg/24 h/IP, MEK1/2i group) and analyzed at 0, 3, 7, and 14 days using microcomputed tomography, histomorphometry, birefringence, immunohistochemistry, and PCR array analysis. The results demonstrate that MEK1/2 inhibition limits the development of M2 response over time, being associated with lower expression of M2, MSCs, and bone markers, lower levels of growth and osteogenic factors, along with a higher expression of iNOS, IL-1b, IL-6, and TNF-α, as well inflammatory chemokines, indicating a predominantly M1 pro-inflammatory environment. This modulation of local inflammatory immune response is associated with impaired bone formation as demonstrated by microtomographic and histomorphometric data. The results show that MEK1/2 inhibition delays bone repair after tooth extraction, supporting the concept that M2 macrophages are essential elements for host response regulation and proper repair.

Molecular Mechanisms Underlying Neuroinflammation Intervention with Medicinal Plants: A Critical and Narrative Review of the Current Literature

Neuroinflammation is a key factor in the progression of neurodegenerative diseases, driven by the dysregulation of molecular pathways and activation of the brain's immune system, resulting in the release of pro-inflammatory and oxidative molecules. This chronic inflammation is exacerbated by peripheral leukocyte infiltration into the central nervous system. Medicinal plants, with their historical use in traditional medicine, have emerged as promising candidates to mitigate neuroinflammation and offer a sustainable alternative for addressing neurodegenerative conditions in a green healthcare framework. This review evaluates the effects of medicinal plants on neuroinflammation, emphasizing their mechanisms of action, effective dosages, and clinical implications, based on a systematic search of databases such as PubMed, SCOPUS, and Web of Science. The key findings highlight that plants like Cleistocalyx nervosum var. paniala, Curcuma longa, Cannabis sativa, and Dioscorea nipponica reduce pro-inflammatory cytokines (TNF-α, IL-6, and IL-1β), inhibit enzymes (COX-2 and iNOS), and activate antioxidant pathways, particularly Nrf2. NF-κB emerged as the primary pro-inflammatory pathway inhibited across studies. While the anti-inflammatory potential of these plants is significant, the variability in dosages and phytochemical compositions limits clinical translation. Here, we highlight that medicinal plants are effective modulators of neuroinflammation, underscoring their therapeutic potential. Future research should focus on animal models, standardized protocols, and safety assessments, integrating advanced methodologies, such as genetic studies and nanotechnology, to enhance their applicability in neurodegenerative disease management.