M2b macrophage polarization and its roles in diseases

Regulation of SETD2 maintains immune regulatory function in macrophages to suppress airway allergy

SET domain-containing 2 (SETD2) is a histone methyltransferase. It regulates the activity of H3K36me3 to enhance gene transcription. Macrophages (Mϕs) are one of the cell types involved in immune response. The purpose of this study is to clarify the role of SETD2 in regulating the immune property of Mϕ. The Mφs were isolated from the bronchoalveolar lavage fluid (BALF) and analysed through flow cytometry and RNA sequencing. A mouse strain carrying Mφs deficient in SETD2 was used. A mouse model of airway allergy was established with the ovalbumin/alum protocol. Less expression of SETD2 was observed in airway Mϕs in patients with allergic asthma. SETD2 of M2 cells was associated with the asthmatic clinical response. Sensitization reduced the expression of SETD2 in mouse respiratory tract M2 cells, which is associated with the allergic reaction. Depletion of SETD2 in Mφs resulted in Th2 pattern inflammation in the lungs. SETD2 maintained the immune regulatory ability in airway M2 cells. SETD2 plays an important role in the maintenance of immune regulatory property of airway Mφs.

Molecular and epigenetic ex vivo profiling of testis cancer-associated fibroblasts and their interaction with germ cell tumor cells and macrophages

Germ cell tumors (GCT) are the most common solid tumors in young men of age 15 - 40. In previous studies, we profiled the interaction of GCT cells with cells of the tumor microenvironment (TM), which showed that especially the 3D interaction of fibroblasts (FB) or macrophages with GCT cells influenced the growth behavior and cisplatin response as well as the transcriptome and secretome of the tumor cells, suggesting that the crosstalk of these cells with GCT cells is crucial for tumor progression and therapy outcome. In this study, we shed light on the mechanisms of activation of cancer-associated fibroblasts (CAF) in the GCT setting and their effects on GCT cells lines and the monocyte cell line THP-1. Ex vivo cultures of GCT-derived CAF were established and characterized molecularly and epigenetically by performing DNA methylation arrays, RNA sequencing, and mass spectrometry-based secretome analysis. We demonstrated that the activation state of CAF is influenced by their former prevailing tumor environment in which they have resided. Hereby, we postulate that seminoma (SE) and embryonal carcinoma (EC) activate CAF, while teratoma (TER) play only a minor role in CAF formation. In turn, CAF influence proliferation and the expression of cisplatin sensitivity-related factors in GCT cells lines as well as polarization of in vitro-induced macrophages by the identified effector molecules IGFBP1, LGALS3BP, LYVE1, and PTX3. Our data suggests that the vital interaction of CAF with GCT cells and with macrophages has a huge influence on shaping the extracellular matrix as well as on recruitment of immune cells to the TM. In conclusion, therapeutically interfering with CAF and / or macrophages in addition to the standard therapy might slow-down progression of GCT and re-shaping of the TM to a tumor-promoting environment. Significance: The interaction of CAF with GCT and macrophages considerably influences the microenvironment. Thus, therapeutically interfering with CAF might slow-down progression of GCT and re-shaping of the microenvironment to a tumor-promoting environment.

The effect of intestinal flora metabolites on macrophage polarization

Intestinal flora metabolites played a crucial role in immunomodulation by influencing host immune responses through various pathways. Macrophages, as a type of innate immune cell, were essential in chemotaxis, phagocytosis, inflammatory responses, and microbial elimination. Different macrophage phenotypes had distinct biological functions, regulated by diverse factors and mechanisms. Advances in intestinal flora sequencing and metabolomics have enhanced understanding of how intestinal flora metabolites affect macrophage phenotypes and functions. These metabolites had varying effects on macrophage polarization and different mechanisms of influence. This study summarized the impact of gut microbiota metabolites on macrophage phenotype and function, along with the underlying mechanisms associated with different metabolites produced by intestinal flora.

Intraperitoneal injection of mesenchymal stem cells-conditioned media (MSCS-CM) treated monocyte can potentially alleviate motor defects in experimental autoimmune encephalomyelitis female mice; An original experimental study

INTRODUCTION

Multiple sclerosis (MS), as a destructive pathology of myelin in central nervous system (CNS), causes physical and mental complications. Experimental autoimmune encephalomyelitis (EAE) is laboratory model of MS widely used for CNS-associated inflammatory researches. Cell therapy using macrophage M2 (MPM2) is a cell type with anti-inflammatory characteristics for all inflammatory-based neuropathies. This experimental study investigated the probable therapeutic anti-inflammatory effects of intraperitoneal (IP) injection of MPM2 on alleviation of motor defect in EAE-affected animals.

MATERIALS AND METHODS

24 C57/BL6 female mice were divided into four groups of EAE, EAE + Dexa, EAE + PBS, and EAE + MP2. EAE was induced through deep cervical injection of spinal homogenate of guinea pigs. MPM2 cells were harvested from bone marrow and injected (106cells/ml) in three days of 10, 13 and 16 post-immunizations (p.i). Clinical score (CS), anti-inflammatory cytokines (IL-4, IL-10), pro-inflammatory gene expression (TNF-α, IL-1β) and histopathological investigations (HE, Nissl and Luxol Fast Blue) were considered. Data were analyzed using SPSS software (v.19) and p < 0.05 was considered significant level.

RESULTS

During EAE induction, the mean animal weight was decreased (p < 0.05); besides, following MPM2 injection, the weight gain was applied (p < 0.05) in EAE + MPM2 groups than control. Increased (p < 0.05) levels of CS was found during EAE induction in days 17-28 in EAE animals; besides, CS was decreased (p < 0.05) in EAE + MPM2 group than EAE animals. Also, in days 25-28 of experiment, the CS was decreased (p < 0.05) in EAE + MPM2 than EAE + Dexa. Histopathological assessments revealed low density of cell nuclei in corpus callosum, microscopically. LFB staining also showed considerable decrease in white matter density of corpus callosum in EAE group. Acceleration of white matter density was found in EAE + MPM2 group following cell therapy procedure. Genes expression of TNF-α, IL-1β along with IL-4 and IL-10 were decreased (p < 0.05) in EAE + MPM2 group.

CONCLUSION

IP injection of MPM2 to EAE-affected female mice can potentially reduce the CNS inflammation, neuronal death and myelin destruction. MPM2 cell therapy can improve animal motor defects.

Podocyte Pathogenic Bone Morphogenetic Protein-2 Pathway and Immune Cell Behaviors in Primary Membranous Nephropathy

Primary membranous nephropathy (PMN) is one of the leading causes of end-stage renal disease, and the most frequent cause of massive proteinuria in nondiabetic adults, resulting in fatal complications. However, the underlying pathomechanisms of PMN remain largely unclear. Here, single-cell RNA sequencing is employed to analyze kidney biopsies from eleven PMN patients and seven healthy subjects. Profiling 44 060 cells from patients allowed us to characterize the cellular composition and cell-type-specific gene expression in the PMN kidney. The complement-induced BMP2/pSMAD1/COL4 pathway is identified as the pathogenic pathway in podocytes, bridging two key events, i.e., complement system activation and glomerular basement membrane thickening in PMN. Augmented infiltration and activation of myeloid leukocytes and B lymphocytes are found, profiling delicate crosstalk of immune cells in PMN kidneys. Overall, these results provide valuable insights into the roles of podocytes and immune cells in PMN, and comprehensive resources toward the complete understanding of PMN pathophysiology.

Faecalibacterium prausnitzii-derived extracellular vesicles alleviate chronic colitis-related intestinal fibrosis by macrophage metabolic reprogramming

Faecalibacterium prausnitzii (F. prausnitzii) has been recognized for its various intestinal and extraintestinal benefits to human. And reduction of F. prausnitzii has been linked to an increased risk of intestinal fibrosis in patients of Crohn's disease (CD). In this study, oral administration of either live F. prausnitzii or its extracellular vesicles (FEVs) can markedly mitigate the severity of fibrosis in mice induced by repetitive administration of DSS. In vitro experiment revealed that FEVs were capable of directing the polarization of peripheral blood mononuclear cells (PBMCs) towards an M2b macrophage phenotype, which has been associated with anti-fibrotic activities. This effect of FEV was found to be stable under various conditions that promote the development of pro-fibrotic M1/M2a/M2c macrophages. Proteomics and RNA sequencing were performed to uncover the molecular modulation of macrophages by FEVs. Notably, we found that FEVs reprogramed every metabolism of macrophages by damaging the mitochondria, and inhibited oxidative phosphorylation and glycolysis. Moreover, FEV-treated macrophages showed a decreased expression of PPARγ and an altered lipid processing phenotype characterized by decreased cholesterol efflux, which may promote energy reprogramming. Taken together, these findings identify FEV as a driver of macrophage reprogramming, suggesting that triggering M2b macrophage polarization by oral admiration of FEV may serve as strategy to alleviate hyperfibrotic intestine conditions in CD.

Endothelial and macrophage interactions in the angiogenic niche

The interactions between vascular cells, especially endothelial cells, and macrophages play a pivotal role in maintaining the subtle balance of vascular biology, which is crucial for angiogenesis in both healthy and diseased states. These cells are central to ensuring a harmonious balance between tissue repair and preventing excessive angiogenic activity, which could lead to pathological conditions. Recent advances in sophisticated genetic engineering vivo models and novel sequencing approaches, such as single-cell RNA-sequencing, in immunobiology have significantly enhanced our understanding of the gene expression and behavior of macrophages. These insights offer new perspectives on the role macrophages play not only in development but also across various health conditions. In this review, we explore the complex interactions between multiple types of macrophages and endothelium, focusing on their impact on new blood vessel formation. By understanding these intricate interactions, we aim to provide insights into new methods for managing angiogenesis in various diseases, thereby offering hope for the development of novel therapeutic approaches.

NIR-II Light-Actuated Nanomotors for Enhanced Photoimmunotherapy Toward Hepatocellular Carcinoma

Light-propelled nanomotors, which can convert external light into mechanical motion, have shown considerable potential in the construction of a new generation of drug delivery systems. However, the therapeutic efficacy of light-driven nanomotors is always unsatisfactory due to the limited penetration depth of near-infrared-I (NIR-I) light and the inherent biocompatibility of the motor itself. Herein, an asymmetric nanomotor (Pd@ZIF-8/R848@M JNMs) with efficient motion capability is successfully constructed for enhanced photoimmunotherapy toward hepatocellular carcinoma. Under near-infrared-II (NIR-II) irradiation, Pd@ZIF-8/R848@M JNMs convert light energy into heat energy, exhibiting self-thermophoretic locomotion to penetrate deeper into tumor tissues to achieve photothermal therapy. At the same time, functionalized with an immune-activated agent Resiquimod (R848), our nanomotors could convert a "cold tumor" into a "hot tumor", transforming the immunosuppressive microenvironment into an immune-activated state, thus achieving immunotherapy. Dual photoimmunotherapy of the as-developed NIR-II light-driven Pd@ZIF-8/R848@M JNMs demonstrates considerable tumor inhibition effects, offering a promising therapeutic approach in the field of anticancer therapy.

Progress in reeducating tumor-associated macrophages in tumor microenvironment

Malignant tumor, one of the most threatening diseases to human health, has been comprehensively treated with surgery, radiotherapy, chemotherapy and targeted therapy, but the prognosis has not always been ideal. In the past decade, immunotherapy has shown increased efficacy in tumor treatment; however, for immunotherapy to achieve its fullest potential, obstacles are to be conquered, among which tumor microenvironment (TME) has been widely investigated. In remodeling the tumor immune microenvironment to inhibit tumor progression, macrophages, as the most abundant innate immune population, play an irreplaceable role in the immune response. Therefore, how to remodel TME and alter the recruitment and polarization status of tumor-associated macrophages (TAM) has been of wide interest. In this context, nanoparticles, photodynamic therapy and other therapeutic approaches capable of affecting macrophage polarization have emerged. In this paper, we categorize and organize the existing means and methods for reprogramming TAM to provide ideas for clinical application of novel tumor-related therapies.

Macrophage polarization and its impact on idiopathic pulmonary fibrosis

Idiopathic pulmonary fibrosis (IPF) is a lung disease that worsens over time, causing fibrosis in the lungs and ultimately resulting in respiratory failure and a high risk of death. Macrophages play a crucial role in the immune system, showing flexibility by transforming into either pro-inflammatory (M1) or anti-inflammatory (M2) macrophages when exposed to different stimuli, ultimately impacting the development of IPF. Recent research has indicated that the polarization of macrophages is crucial in the onset and progression of IPF. M1 macrophages secrete inflammatory cytokines and agents causing early lung damage and fibrosis, while M2 macrophages support tissue healing and fibrosis by releasing anti-inflammatory cytokines. Developing novel treatments for IPF relies on a thorough comprehension of the processes involved in macrophage polarization in IPF. The review outlines the regulation of macrophage polarization and its impact on the development of IPF, with the goal of investigating the possible therapeutic benefits of macrophage polarization in the advancement of IPF.

Alcohol inducing macrophage M2b polarization in colitis by modulating the TRPV1-MAPK/NF-κB pathways

BACKGROUND

Macrophages exhibit different phenotypes in inflammatory bowel disease (IBD) and promote inflammation or tissue repair depending on their polarization state. Alcohol is a widely used solvent in pharmaceutical formulations, and its consumption is associated with an increased risk of colitis; however, its effects on macrophages in IBD remain poorly understood.

PURPOSE

This study aimed to investigate the effect of alcohol on macrophages in dextran sodium sulfate (DSS)-induced colitis and understand the underlying mechanisms.

METHODS

DSS-treated C57BL/6 mice were exposed to varying concentrations of alcohol, transient receptor potential vanilloid 1 (TRPV1) antagonist, and 5-aminosalicylic acid. The distal colon was resected, fixed, stained, and histologically analyzed, through hematoxylin and eosin (H&E) staining and immunofluorescence staining. Ratio [Ca2+]i measurements, western blotting, quantitative polymerase chain reaction, cytokine measurements, and RNA sequencing analyses were also performed. Peritoneal macrophages and RAW264.7 cells were used for in vitro experiments, and various assays were performed to evaluate cellular responses, gene expression, and signaling pathways.

RESULTS

Alcohol exacerbated DSS-treated mice colitis and promoted the secretion of various inflammatory cytokines from colonic macrophages. Alcohol enhances the calcium ion influx induced by lipopolysaccharide (LPS) in peritoneal macrophages, while the TRPV1 antagonist capsazepine (CPZ) inhibits LPS- and/or alcohol- induced calcium influx in macrophages. Alcohol and LPS activate the MAPK/P38, MAPK/ERK, and NF-κB signaling pathways and induce the macrophage M2b polarization, resulting in the increased expression level of inflammatory cytokines such as Tnf, Il1b, and Il10. Additionally, CPZ can inhibit the facilitatory effects of alcohol or LPS on the abovementioned pathways and inflammatory factors, reversing macrophage M2b polarization and promoting alcohol-induced colitis. The inhibition of nucleotide binding oligomerization domain containing 2 (NOD2) partially suppressed the alcohol and LPS effects on macrophages.

CONCLUSION

Alcohol exacerbates experimental colitis and induces M2b polarization of macrophage via TRPV1-MAPK/NF-κB. Our study provides new insights into the potential therapeutic targets for IBD treatment by elucidating the role of TRPV1 in alcohol-exacerbated colitis, using CPZ as a potential therapeutic option. The identification of transient receptor potential ankyrin subtype 1 (TRPA1) as a therapeutic target expands the scope of future research.

Role of macrophage polarization in heart failure and traditional Chinese medicine treatment

Heart failure (HF) has a severe impact on public health development due to high morbidity and mortality and is associated with imbalances in cardiac immunoregulation. Macrophages, a major cell population involved in cardiac immune response and inflammation, are highly heterogeneous and polarized into M1 and M2 types depending on the microenvironment. M1 macrophage releases inflammatory factors and chemokines to activate the immune response and remove harmful substances, while M2 macrophage releases anti-inflammatory factors to inhibit the overactive immune response and promote tissue repair. M1 and M2 restrict each other to maintain cardiac homeostasis. The dynamic balance of M1 and M2 is closely related to the Traditional Chinese Medicine (TCM) yin-yang theory, and the imbalance of yin and yang will result in a pathological state of the organism. Studies have confirmed that TCM produces positive effects on HF by regulating macrophage polarization. This review describes the critical role of macrophage polarization in inflammation, fibrosis, angiogenesis and electrophysiology in the course of HF, as well as the potential mechanism of TCM regulation of macrophage polarization in preventing and treating HF, thereby providing new ideas for clinical treatment and scientific research design of HF.

Understanding lactate in the development of Hepatitis B virus-related hepatocellular carcinoma

Hepatitis B Virus (HBV) is a hepatotropic virus that can establish a persistent and chronic infection in humans. Chronic hepatitis B (CHB) infection is associated with an increased risk of hepatic decompensation, cirrhosis, and hepatocellular carcinoma (HCC). Lactate level, as the end product of glycolysis, plays a substantial role in metabolism beyond energy production. Emerging studies indicate that lactate is linked to patient mortality rates, and HBV increases overall glucose consumption and lactate production in hepatocytes. Excessive lactate plays a role in regulating the tumor microenvironment (TME), immune cell function, autophagy, and epigenetic reprogramming. The purpose of this review is to gather and summarize the existing knowledge of the lactate's functions in the dysregulation of the immune system, which can play a crucial role in the development of HBV-related HCC. Therefore, it is reasonable to hypothesize that lactate with intriguing functions can be considered an immunomodulatory metabolite in immunotherapy.

Decoding ecosystem heterogeneity and transcriptional regulation characteristics of multi-subtype renal cell carcinoma

Background

Renal cell carcinoma (RCC) is characterized by its heterogeneity and the complexity of its tumor microenvironment. This study addresses the need to understand RCC at a cellular level, with a focus on its three main subtypes: clear cell (ccRCC), chromophobe (chRCC), and papillary renal cell carcinoma (pRCC).

Objective

This study aims to comprehensively characterize the cellular diversity and intercellular communication networks of RCC subtypes using scRNA-seq technology. By focusing on macrophages and cancer-associated fibroblasts (CAFs), we seek to reveal their functional states, developmental trajectories, and signaling pathways.

Methodology

We utilized single-cell RNA sequencing (scRNA-seq) data from various kidney cancer subtypes. Advanced analytical techniques, including Uniform Manifold Approximation and Projection (UMAP) and Reactome Gene Set Variation Analysis (ReactomeGSA), were employed to assess cellular heterogeneity and pathway activities. The developmental dynamics of macrophages were studied using CytoTRACE, and cell-to-cell communication was analyzed to identify subtype-specific interaction networks.

Results

Our comprehensive analysis revealed significant cellular diversity within RCC. Distinct macrophage and CAF subpopulations were identified, each exhibiting unique gene expression profiles and pathway activities. Notably, ccRCC showed prominent bidirectional communication between macrophages and CAFs, while chRCC and pRCC displayed disrupted signaling pathways. Metabolic pathway analysis reflected the adaptability of macrophages and CAFs to the tumor microenvironment, and the MIF signaling pathway was identified as a key mediator of cellular interactions.

Conclusion

The study highlights the cellular heterogeneity and the intricate communication networks within RCC subtypes, underscoring the complexity of the tumor microenvironment. Our findings suggest that targeting specific cellular interactions and pathways may offer new avenues for therapeutic intervention in RCC. The unique macrophage and CAF profiles across RCC subtypes provide valuable insights for the development of personalized and targeted treatment strategies.

Macrophages and HLA-Class II Alleles in Multiple Sclerosis: Insights in Therapeutic Dynamics

Antigen presentation is a crucial mechanism that drives the T cell-mediated immune response and the development of Multiple Sclerosis (MS). Genetic alterations within the highly variable Major Histocompatibility Complex Class II (MHC II) have been proven to result in significant changes in the molecular basis of antigen presentation and the clinical course of patients with both Adult-Onset MS (AOMS) and Pediatric-Onset MS (POMS). Among the numerous polymorphisms of the Human Leucocyte Antigens (HLA), within MHC II complex, HLA-DRB1*15:01 has been labeled, in Caucasian ethnic groups, as a high-risk allele for MS due to the ability of its structure to increase affinity to Myelin Basic Protein (MBP) epitopes. This characteristic, among others, in the context of the trimolecular complex or immunological synapsis, provides the foundation for autoimmunity triggered by environmental or endogenous factors. As with all professional antigen presenting cells, macrophages are characterized by the expression of MHC II and are often implicated in the formation of MS lesions. Increased presence of M1 macrophages in MS patients has been associated both with progression and onset of the disease, each involving separate but similar mechanisms. In this critical narrative review, we focus on macrophages, discussing how HLA genetic alterations can promote dysregulation of this population's homeostasis in the periphery and the Central Nervous System (CNS). We also explore the potential interconnection in observed pathological macrophage mechanisms and the function of the diverse structure of HLA alleles in neurodegenerative CNS, seen in MS, by comparing available clinical with molecular data through the prism of HLA-immunogenetics. Finally, we discuss available and experimental pharmacological approaches for MS targeting the trimolecular complex that are based on cell phenotype modulation and HLA genotype involvement and try to reveal fertile ground for the potential development of novel drugs.

Harnessing the potential of monocytes/macrophages to regenerate tissue-engineered vascular grafts

Cell-free tissue-engineered vascular grafts provide a promising alternative to treat cardiovascular disease, but timely endothelialization is essential for ensuring patency and proper functioning post-implantation. Recent studies from our lab showed that blood cells like monocytes (MCs) and macrophages (Mϕ) may contribute directly to cellularization and regeneration of bioengineered arteries in small and large animal models. While MCs and Mϕ are leucocytes that are part of the innate immune response, they share common developmental origins with endothelial cells (ECs) and are known to play crucial roles during vessel formation (angiogenesis) and vessel repair after inflammation/injury. They are highly plastic cells that polarize into pro-inflammatory and anti-inflammatory phenotypes upon exposure to cytokines and differentiate into other cell types, including EC-like cells, in the presence of appropriate chemical and mechanical stimuli. This review focuses on the developmental origins of MCs and ECs; the role of MCs and Mϕ in vessel repair/regeneration during inflammation/injury; and the role of chemical signalling and mechanical forces in Mϕ inflammation that mediates vascular graft regeneration. We postulate that comprehensive understanding of these mechanisms will better inform the development of strategies to coax MCs/Mϕ into endothelializing the lumen and regenerate the smooth muscle layers of cell-free bioengineered arteries and veins that are designed to treat cardiovascular diseases and perhaps the native vasculature as well.

Targeting Macrophage Polarization for Reinstating Homeostasis following Tissue Damage

Tissue regeneration and remodeling involve many complex stages. Macrophages are critical in maintaining micro-environmental homeostasis by regulating inflammation and orchestrating wound healing. They display high plasticity in response to various stimuli, showing a spectrum of functional phenotypes that vary from M1 (pro-inflammatory) to M2 (anti-inflammatory) macrophages. While transient inflammation is an essential trigger for tissue healing following an injury, sustained inflammation (e.g., in foreign body response to implants, diabetes or inflammatory diseases) can hinder tissue healing and cause tissue damage. Modulating macrophage polarization has emerged as an effective strategy for enhancing immune-mediated tissue regeneration and promoting better integration of implantable materials in the host. This article provides an overview of macrophages' functional properties followed by discussing different strategies for modulating macrophage polarization. Advances in the use of synthetic and natural biomaterials to fabricate immune-modulatory materials are highlighted. This reveals that the development and clinical application of more effective immunomodulatory systems targeting macrophage polarization under pathological conditions will be driven by a detailed understanding of the factors that regulate macrophage polarization and biological function in order to optimize existing methods and generate novel strategies to control cell phenotype.

Direct Current Electrical Stimulation Shifts THP-1-Derived Macrophage Polarization towards Pro-Regenerative M2 Phenotype

A macrophage shift from the M1 to the M2 phenotype is relevant for promoting tissue repair and regeneration. In a previous in vivo study, we found that direct current (DC) electrical stimulation (EStim) increased the proportion of M2 macrophages in healing tissues and directed the balance of the injury response away from healing/scarring towards regeneration. These observations led us to hypothesize that DC EStim regulates macrophage polarization towards an M2 phenotype. THP-1-derived M0, M1 (IFN-γ and LPS), and M2 (IL-4 and IL-13) macrophages were exposed (or not: control group) to 100 mV/mm of DC EStim, 1 h/day for three days. Macrophage polarization was assessed through gene and surface marker expressions and cytokine secretion profiles. Following DC EStim treatment, M0 cells exhibited an upregulation of M2 marker genes IL10, CD163, and PPARG. In M1 cells, DC EStim upregulated the gene expressions of M2 markers IL10, TGM2, and CD206 and downregulated M1 marker gene CD86. EStim treatment also reduced the surface expression of CD86 and secretion of pro-inflammatory cytokines IL-1β and IL-6. Our results suggest that DC EStim differentially exerts pro-M2 effects depending on the macrophage phenotype: it upregulates typical M2 genes in M0 and M1 cells while inhibiting M1 marker CD86 at the nuclear and protein levels and the secretion of pro-inflammatory interleukins in M1 cells. Conversely, M2 cells appear to be less responsive to the EStim treatment employed in this study.

Protective effects of Amauroderma rugosum on dextran sulfate sodium-induced ulcerative colitis through the regulation of macrophage polarization and suppression of oxidative stress

BACKGROUND

Amauroderma rugosum (AR) is a medicinal mushroom commonly used to treat inflammation, gastric disorders, epilepsy, and cancers due to its remarkable anti-inflammatory and anti-oxidative properties. This study was designed to evaluate the pharmacological effects of AR and its underlying mechanism of action against ulcerative colitis (UC) in vitro and in vivo.

METHODS

A UC mouse model was established by administration of dextran sulfate sodium (DSS). AR extract was administered intragastrically to mice for 7 days. At the end of the experiment, histopathology, macrophage phenotype, oxidative stress, and inflammatory status were examined in vivo. Furthermore, RAW 264.7, THP-1, and Caco-2 cells were used to elucidate the mechanism of action of AR in vitro.

RESULTS

AR extract (0.5-2 mg/mL) significantly suppressed lipopolysaccharide (LPS) and interferon-gamma (IFN-γ)-induced M1 macrophage (pro-inflammatory) polarization in both RAW 264.7 and THP-1 cells. LPS-induced pro-inflammatory mediators (nitric oxide, TNF-α, IL-1β, MCP-1, and IL-6) were reduced by AR extract in a concentration-dependent manner. Similarly, AR extract downregulated MAPK signaling activity in LPS-stimulated RAW 264.7 cells. AR extract elicited a concentration-dependent increase in the mRNA expression of M2 (anti-inflammatory) phenotype markers (CD206, Arg-1, Fizz-1, and Ym-1) in RAW 264.7 cells. Moreover, AR extract suppressed DSS-induced ROS generation and mitochondrial dysfunction in Caco-2 cells. The in vivo experiment revealed that AR extract (200 mg/kg) increased colon length compared to the DSS-treated group. In addition, disease activity index, spleen ratio, body weight, oxidative stress, and colonic inflammation were markedly improved by AR treatment in DSS-induced UC mice. Finally, AR suppressed M1 and promoted M2 macrophage polarization in UC mice.

CONCLUSION

The AR extract protected against DSS-induced UC by regulating macrophage polarization and suppressing oxidative stress. These valuable findings suggest that adequate intake of AR can prevent and/or treat UC.

Interrelation of adipose tissue macrophages and fibrosis in obesity

Obesity is characterized by adipose tissue expansion, extracellular matrix remodelling and unresolved inflammation that contribute to insulin resistance and fibrosis. Adipose tissue macrophages represent the most abundant class of immune cells in adipose tissue inflammation and could be key mediators of adipocyte dysfunction and fibrosis in obesity. Although macrophage activation states are classically defined by the M1/M2 polarization nomenclature, novel studies have revealed a more complex range of macrophage phenotypes in response to external condition or the surrounding microenvironment. Here, we discuss the plasticity of adipose tissue macrophages (ATMs) in response to their microenvironment in obesity, with special focus on macrophage infiltration and polarization, and their contribution to adipose tissue fibrosis. A better understanding of the role of ATMs as regulators of adipose tissue remodelling may provide novel therapeutic strategies against obesity and associated metabolic diseases.

A Novel TGFβ Receptor Inhibitor, IPW-5371, Prevents Diet-induced Hepatic Steatosis and Insulin Resistance in Irradiated Mice

As the number of cancer survivors increases and the risk of accidental radiation exposure rises, there is a pressing need to characterize the delayed effects of radiation exposure and develop medical countermeasures. Radiation has been shown to damage adipose progenitor cells and increase liver fibrosis, such that it predisposes patients to developing metabolic-associated fatty liver disease (MAFLD) and insulin resistance. The risk of developing these conditions is compounded by the global rise of diets rich in carbohydrates and fats. Radiation persistently increases the signaling cascade of transforming growth factor β (TGFβ), leading to heightened fibrosis as characteristic of the delayed effects of radiation exposure. We investigate here a potential radiation medical countermeasure, IPW-5371, a small molecule inhibitor of TGFβRI kinase (ALK5). We found that mice exposed to sub-lethal whole-body irradiation and chronic Western diet consumption but treated with IPW-5371 had a similar body weight, food consumption, and fat mass compared to control mice exposed to radiation. The IPW-5371 treated mice maintained lower fibrosis and fat accumulation in the liver, were more responsive to insulin and had lower circulating triglycerides and better muscle endurance. Future studies are needed to verify the improvement by IPW-5371 on the structure and function of other metabolically active tissues such as adipose and skeletal muscle, but these data demonstrate that IPW-5371 protects liver and whole-body health in rodents exposed to radiation and a Western diet, and there may be promise in using IPW-5371 to prevent the development of MAFLD.

Modulating the immune system towards a functional chronic wound healing: A biomaterials and Nanomedicine perspective

Chronic non-healing wounds persist as a substantial burden for healthcare systems, influenced by factors such as aging, diabetes, and obesity. In contrast to the traditionally pro-regenerative emphasis of therapies, the recognition of the immune system integral role in wound healing has significantly grown, instigating an approach shift towards immunological processes. Thus, this review explores the wound healing process, highlighting the engagement of the immune system, and delving into the behaviors of innate and adaptive immune cells in chronic wound scenarios. Moreover, the article investigates biomaterial-based strategies for the modulation of the immune system, elucidating how the adjustment of their physicochemical properties or their synergistic combination with other agents such as drugs, proteins or mesenchymal stromal cells can effectively modulate the behaviors of different immune cells. Finally this review explores various strategies based on synthetic and biological nanostructures, including extracellular vesicles, to finely tune the immune system as natural immunomodulators or therapeutic nanocarriers with promising biophysical properties.

Mangiferin: A natural bioactive immunomodulating glucosylxanthone with potential against cancer and rheumatoid arthritis

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.

Chronic NOD2 stimulation by MDP confers protection against parthanatos through M2b macrophage polarization in RAW264.7 cells

Innate immune cells show enhanced responsiveness to secondary challenges after an initial non-related stimulation (Trained Innate Immunity, TII). Acute NOD2 activation by Muramyl-Dipeptide (MDP) promotes TII inducing the secretion of pro-inflammatory mediators, while a sustained MDP-stimulation down-regulates the inflammatory response, restoring tolerance. Here we characterized in-vitro the response of murine macrophages to lipopolysaccharide (LPS) challenge under NOD2-chronic stimulation. RAW264.7 cells were trained with MDP (1 μg/ml, 48 h) and challenged with LPS (5 μg/ml, 24 h). Trained cells formed multinucleated giant cells with increased phagocytosis rates compared to untrained/challenged cells. They showed a reduced mitochondrial activity and a switch to aerobic glycolysis. TNF-α, ROS and NO were upregulated in both trained and untrained cultures (MDP+, MDP- cells, p > 0.05); while IL-10, IL-6 IL-12 and MHCII were upregulated only in trained cells after LPS challenge (MDP + LPS+, p < 0.05). A slight upregulation in the expression of B7.2 was also observed in this group, although differences were not statistically significant. MDP-training induced resistance to LPS challenge (p < 0.01). The relative expression of PARP-1 was downregulated after the LPS challenge, which may contribute to the regulatory milieu and to the innate memory mechanisms exhibited by MDP-trained cells. Our results demonstrate that a sustained MDP-training polarizes murine macrophages towards a M2b profile, inhibiting parthanatos. These results may impact on the development of strategies to immunomodulate processes in which inflammation should be controlled.

Immunoregulatory role of platelet derivatives in the macrophage-mediated immune response

Background

Macrophages are innate immune cells that display remarkable phenotypic heterogeneity and functional plasticity. Due to their involvement in the pathogenesis of several human conditions, macrophages are considered to be an attractive therapeutic target. In line with this, platelet derivatives have been successfully applied in many medical fields and as active participants in innate immunity, cooperation between platelets and macrophages is essential. In this context, the aim of this review is to compile the current evidence regarding the effects of platelet derivatives on the phenotype and functions of macrophages to identify the advantages and shortcomings for feasible future clinical applications.

Methods

A total of 669 articles were identified during the systematic literature search performed in PubMed and Web of Science databases.

Results

A total of 27 articles met the inclusion criteria. Based on published findings, platelet derivatives may play an important role in inducing a dynamic M1/M2 balance and promoting a timely M1-M2 shift. However, the differences in procedures regarding platelet derivatives and macrophages polarization and the occasional lack of information, makes reproducibility and comparison of results extremely challenging. Furthermore, understanding the differences between human macrophages and those derived from animal models, and taking into account the peculiarities of tissue resident macrophages and their ontogeny seem essential for the design of new therapeutic strategies.

Conclusion

Research on the combination of macrophages and platelet derivatives provides relevant information on the function and mechanisms of the immune response.

Correlation of Ktrans derived from dynamic contrast-enhanced MRI with treatment response and survival in locally advanced NSCLC patients undergoing induction immunochemotherapy and concurrent chemoradiotherapy

PURPOSE

This study aimed to investigate the prognostic significance of pretreatment dynamic contrast-enhanced (DCE)-MRI parameters concerning tumor response following induction immunochemotherapy and survival outcomes in patients with locally advanced non-small cell lung cancer (NSCLC) who underwent immunotherapy-based multimodal treatments.

MATERIAL AND METHODS

Unresectable stage III NSCLC patients treated by induction immunochemotherapy, concurrent chemoradiotherapy (CCRT) with or without consolidative immunotherapy from two prospective clinical trials were screened. Using the two-compartment Extend Tofts model, the parameters including Ktrans, Kep, Ve, and Vp were calculated from DCE-MRI data. The apparent diffusion coefficient was calculated from diffusion-weighted-MRI data. The receiver operating characteristic (ROC) curve and the area under the curve (AUC) were used to assess the predictive performance of MRI parameters. The Cox regression model was used for univariate and multivariate analysis.

RESULTS

111 unresectable stage III NSCLC patients were enrolled. Patients received two cycles of induction immunochemotherapy and CCRT, with or without consolidative immunotherapy. With the median follow-up of 22.3 months, the median progression-free survival (PFS) and overall survival (OS) were 16.3 and 23.8 months. The multivariate analysis suggested that Eastern Cooperative Oncology Group score, TNM stage and the response to induction immunochemotherapy were significantly related to both PFS and OS. After induction immunochemotherapy, 67 patients (59.8%) achieved complete response or partial response and 44 patients (40.2%) had stable disease or progressive disease. The Ktrans of primary lung tumor before induction immunochemotherapy yielded the best performance in predicting the treatment response, with an AUC of 0.800. Patients were categorized into two groups: high-Ktrans group (n=67, Ktrans＞164.3×10-3/min) and low-Ktrans group (n=44, Ktrans≤164.3×10-3/min) based on the ROC analysis. The high-Ktrans group had a significantly higher objective response rate than the low-Ktrans group (85.1% (57/67) vs 22.7% (10/44), p<0.001). The high-Ktrans group also presented better PFS (median: 21.1 vs 11.3 months, p=0.002) and OS (median: 34.3 vs 15.6 months, p=0.035) than the low-Ktrans group.

CONCLUSIONS

Pretreatment Ktrans value emerged as a significant predictor of the early response to induction immunochemotherapy and survival outcomes in unresectable stage III NSCLC patients who underwent immunotherapy-based multimodal treatments. Elevated Ktrans values correlated positively with enhanced treatment response, leading to extended PFS and OS durations.

Macrophages in CRSwNP: Do they deserve more attention?

Chronic rhinosinusitis (CRS) represents a heterogeneous disorder primarily characterized by the persistent inflammation of the nasal cavity and paranasal sinuses. The subtype known as chronic rhinosinusitis with nasal polyposis (CRSwNP) is distinguished by a significantly elevated recurrence rate and augmented challenges in the management of nasal polyps. The pathogenesis underlying this subtype remains incompletely understood. Macrophages play a crucial role in mediating the immune system's response to inflammatory stimuli. These cells exhibit remarkable plasticity and heterogeneity, differentiating into either the pro-inflammatory M1 phenotype or the anti-inflammatory and reparative M2 phenotype depending on the surrounding microenvironment. In CRSwNP, macrophages demonstrate reduced production of Interleukin 10 (IL-10), compromised phagocytic activity, and decreased autophagy. Dysregulation of pro-resolving mediators may occur during the inflammatory resolution process, which could potentially hinder the adequate functioning of anti-inflammatory macrophages in facilitating resolution. Collectively, these factors may contribute to the prolonged inflammation observed in CRSwNP. Additionally, macrophages may enhance fibrin cross-linking through the release of factor XIII-A (FAXIII), promoting fibrin deposition and plasma protein retention. Macrophages also modulate vascular permeability by releasing Vascular endothelial growth factor (VEGF). Moreover, they may disrupt the balance between Matrix Metalloproteinases (MMPs) and Tissue Inhibitors of Metalloproteinases (TIMPs), which favors extracellular matrix (ECM) degradation, edema formation, and pseudocyst development. Accumulating evidence suggests a close association between macrophage infiltration and CRSwNP; however, the precise mechanisms underlying this relationship warrant further investigation. In different subtypes of CRSwNP, different macrophage phenotypic aggregations trigger different types of inflammatory features. Increasing evidence suggests that macrophage infiltration is closely associated with CRSwNP, but the mechanism and the relationship between macrophage typing and CRSwNP endophenotyping remain to be further explored. This review discusses the role of different types of macrophages in the pathogenesis of different types of CRSwNP and their contribution to polyp formation, in the hope that a better understanding of the role of macrophages in specific CRSwNP will contribute to a precise and individualized understanding of the disease.

Deciphering the performance of macrophages in tumour microenvironment: a call for precision immunotherapy

Macrophages infiltrating tumour tissues or residing in the microenvironment of solid tumours are known as tumour-associated macrophages (TAMs). These specialized immune cells play crucial roles in tumour growth, angiogenesis, immune regulation, metastasis, and chemoresistance. TAMs encompass various subpopulations, primarily classified into M1 and M2 subtypes based on their differentiation and activities. M1 macrophages, characterized by a pro-inflammatory phenotype, exert anti-tumoural effects, while M2 macrophages, with an anti-inflammatory phenotype, function as protumoural regulators. These highly versatile cells respond to stimuli from tumour cells and other constituents within the tumour microenvironment (TME), such as growth factors, cytokines, chemokines, and enzymes. These stimuli induce their polarization towards one phenotype or another, leading to complex interactions with TME components and influencing both pro-tumour and anti-tumour processes.This review comprehensively and deeply covers the literature on macrophages, their origin and function as well as the intricate interplay between macrophages and the TME, influencing the dual nature of TAMs in promoting both pro- and anti-tumour processes. Moreover, the review delves into the primary pathways implicated in macrophage polarization, examining the diverse stimuli that regulate this process. These stimuli play a crucial role in shaping the phenotype and functions of macrophages. In addition, the advantages and limitations of current macrophage based clinical interventions are reviewed, including enhancing TAM phagocytosis, inducing TAM exhaustion, inhibiting TAM recruitment, and polarizing TAMs towards an M1-like phenotype. In conclusion, while the treatment strategies targeting macrophages in precision medicine show promise, overcoming several obstacles is still necessary to achieve an accessible and efficient immunotherapy.

Macrophage fate: to kill or not to kill?

Macrophages are dynamic innate immune cells that either reside in tissue, serving as sentinels, or recruited as monocytes from bone marrow into inflamed and infected tissue. In response to cues in the tissue microenvironment (TME), macrophages polarize on a continuum toward M1 or M2 with diverse roles in progression and resolution of disease. M1-like macrophages exhibit proinflammatory functions with antimicrobial and anti-tumorigenic activities, while M2-like macrophages have anti-inflammatory functions that generally resolve inflammatory responses and orchestrate a tissue healing process. Given these opposite phenotypes, proper spatiotemporal coordination of macrophage polarization in response to cues within the TME is critical to effectively resolve infectious disease and regulate wound healing. However, if this spatiotemporal coordination becomes disrupted due to persistent infection or dysregulated coagulation, macrophages' inappropriate response to these cues will result in the development of diseases with clinically unfavorable outcomes. Since plasticity and heterogeneity are hallmarks of macrophages, they are attractive targets for therapies to reprogram toward specific phenotypes that could resolve disease and favor clinical prognosis. In this review, we discuss how basic science studies have elucidated macrophage polarization mechanisms in TMEs during infections and inflammation, particularly coagulation. Therefore, understanding the dynamics of macrophage polarization within TMEs in diseases is important in further development of targeted therapies.

Advancements of Macrophages Involvement in Pathological Progression of Colitis-Associated Colorectal Cancer and Associated Pharmacological Interventions

Intestinal macrophages play crucial roles in both intestinal inflammation and immune homeostasis. They can adopt two distinct phenotypes, primarily determined by environmental cues. These phenotypes encompass the classically activated pro-inflammatory M1 phenotype, as well as the alternatively activated anti-inflammatory M2 phenotype. In regular conditions, intestinal macrophages serve to shield the gut from inflammatory harm. However, when a combination of genetic and environmental elements influences the polarization of these macrophages, it can result in an M1/M2 macrophage activation imbalance, subsequently leading to a loss of control over intestinal inflammation. This shift transforms normal inflammatory responses into pathological damage within the intestines. In patients with ulcerative colitis-associated colorectal cancer (UC-CRC), disorders related to intestinal inflammation are closely correlated with an imbalance in the polarization of intestinal M1/M2 macrophages. Therefore, reinstating the equilibrium in M1/M2 macrophage polarization could potentially serve as an effective approach to the prevention and treatment of UC-CRC. This paper aims to scrutinize the clinical evidence regarding Chinese medicine (CM) in the treatment of UC-CRC, the pivotal role of macrophage polarization in UC-CRC pathogenesis, and the potential mechanisms through which CM regulates macrophage polarization to address UC-CRC. Our objective is to offer fresh perspectives for clinical application, fundamental research, and pharmaceutical advancement in UC-CRC.

Physically active pregnancies: Insights from the placenta

Physical activity (PA) positively influences pregnancy, a critical period for health promotion, and affects placental structure and function in ways previously overlooked. Here, we summarize the current body of literature examining the association between PA, placenta biology, and physiology while also highlighting areas where gaps in knowledge exist. PA during pregnancy induces metabolic changes, influencing nutrient availability and transporter expression in the placenta. Hormones and cytokines secreted during PA contribute to health benefits, with intricate interactions in pro- and anti-inflammatory markers. Extracellular vesicles and placental "-omics" data suggest that gestational PA can shape placental biology, affecting gene expression, DNA methylation, metabolite profiles, and protein regulation. However, whether cytokines that respond to PA alter placental proteomic profiles during pregnancy remains to be elucidated. The limited research on placenta mitochondria of physically active gestational parents (gesP), has shown improvements in mitochondrial DNA and antioxidant capacity, but the relationship between PA, placental mitochondrial dynamics, and lipid metabolism remains unexplored. Additionally, PA influences the placenta-immune microenvironment, angiogenesis, and may confer positive effects on neurodevelopment and mental health through placental changes, vascularization, and modulation of brain-derived neurotrophic factor. Ongoing exploration is crucial for unraveling the multifaceted impact of PA on the intricate placental environment.

In vitro study of cold atmospheric plasma-activated liquids inhibits malignant melanoma by affecting macrophage polarization through the ROS/JAK2/STAT1 pathway

Melanoma is a prevalent malignant skin tumor known for its high invasive ability and a high rate of metastasis, making clinical treatment exceptionally challenging. Tumor-associated macrophages (TAMs) are the most abundant immune cells in the tumor microenvironment and play a crucial role in tumor survival and development. Cold atmospheric plasma (CAP) is an emerging tool for tumor treatment that has garnered attention from scholars due to its interaction with non-tumor cells in the tumor microenvironment. Here, we used the macrophage lines THP-1 and RAW264.7, as well as the melanoma cell lines A375 and MV3, as research subjects to investigate the effect of plasma-activated liquid (PAL) on macrophage differentiation and its inhibitory effect on melanoma cell proliferation. We confirmed that the killing effect of PAL on melanoma cells was selective. Using flow cytometry and PCR, we discovered that PAL can influence macrophage differentiation. Through in vitro cell coculture, we demonstrated that PAL-treated macrophages can significantly impede tumor cell development and progression, and the effect is more potent than that of PAL directly targeting tumor cells. Furthermore, we have proposed the hypothesis that PAL promotes the differentiation of macrophages into the M1 type through the ROS/JAK2/STAT1 pathway. To test the hypothesis, we employed catalase and fludarabine to block different sites of the pathway. The results were then validated through Western Blot, qPCR and ELISA. This study illustrates that PAL therapy is an effective tumor immunotherapy and expands the scope of tumor immunotherapy. Furthermore, these findings establish a theoretical foundation for potential clinical applications of PAL.

IL-4 attenuates myocardial infarction injury by promoting M2 macrophage polarization

IL-4, an immunoregulatory cytokine, plays a role in various cellular pathways and is known to regulate M2 macrophage polarization. Numerous studies have suggested that promoting the polarization of macrophages toward the M2 phenotype is beneficial for myocardial infarction (MI) recovery. However, whether IL-4 can achieve therapeutic effects in MI by regulating M2 macrophage polarization remains unclear. In this study, the authors observed that IL-4 increased the proportion of M2 macrophages in the ischemic myocardium compared to the PBS group. Additionally, IL-4 reduced the infiltration of inflammatory cells and the expression of proinflammatory-related proteins, while enhancing the expression of genes associated with tissue repair. Furthermore, IL-4 facilitated the recovery of cardiac function and reduced fibrosis in the post-MI phase. Importantly, when macrophages were depleted, the therapeutic benefits of IL-4 mentioned above were attenuated. These findings provide evidence for the effectiveness of IL-4 in treating MI through the regulation of M2 macrophage polarization, thereby encouraging further development of this therapeutic approach.

Interaction of Macrophages with Bone Healing Microenvironment: Mechanism and Biomaterials

Extensive bone fractures, which can seriously impact both health and quality of life, cannot easily heal naturally, especially if the patient has an underlying medical condition or is aging. The most promising approach to addressing such fractures is bone regeneration through bone tissue engineering. Bone regeneration is a complex process that consists of three distinct phases: inflammation, repair, and remodeling. Macrophages play a bridging role between the various cells involved in each stage of bone regeneration, interacting with different microenvironments and advancing the bone healing process. Although the origin and function of macrophages have been extensively studied, the mechanisms underlying their interaction with the bone healing microenvironment remain unexplored, including the association of microenvironmental changes with macrophage reprogramming and the role of macrophages in cells in the microenvironment. This review summarizes the bone regeneration process and recent advances in research on interactions between macrophages and the bone healing microenvironment and discusses novel biological strategies to promote bone regeneration by modulating macrophages for the treatment of bone injury and loss.

IRX5's influence on macrophage polarization and outcome in papillary thyroid cancer

Background

With a rise in recent years, thyroid cancer (TC) is the most prevalent hormonal cancer worldwide. It is essential to investigate the inherent variability at the molecular level and the immune environment within tumors of various thyroid cancer subtypes in order to identify potential targets for therapy and provide precise treatment for patients with thyroid adenocarcinoma.

Methods

First, we analyzed the expression of IRX5 in pan-cancer and papillary thyroid carcinoma by bioinformatics methods and collected paired samples from our center for validation. Subsequently, we analyzed the significance of IRX5 on the prognosis and diagnosis of PTC. Next, we explored the possible mechanisms by which IRX5 affects the prognosis of thyroid cancer patients by GO/KEGG enrichment analysis, and further investigated the effect of IRX5 on immune infiltration of thyroid cancer. Ultimately, by conducting experiments on cells and animals, we were able to show how IRX5 impacts the aggressive characteristics of thyroid cancer cells and its influence on macrophages within the immune system of thyroid cancer.

Results

In 11 malignant tumors, including PTC, IRX5 is overexpressed and associated with a poor prognosis. IRX5 may affect the prognosis of PTC through embryonic organ development, ossification, mesenchyme development, etc. Increased IRX5 expression decreases the presence of cytotoxic and Th17 cells in papillary thyroid cancer. IRX5 was highly expressed in different PTC cell lines, such as K-1 and TPC-1. Silencing IRX5 effectively halted the growth and movement of PTC cells while also decreasing M2 polarization and enhancing M1 polarization in tumor-associated macrophages.

Conclusion

IRX5 could impact the outlook of individuals with PTC by stimulating the shift of macrophages to M2 in the immune surroundings of thyroid cancer growths, suggesting a potential new focus for treating thyroid cancer, particularly through immunotherapy.

Lipopolysaccharide pretreatment increases the sensitivity of the TRPV1 channel and promotes an anti-inflammatory phenotype of capsaicin-activated macrophages

BACKGROUND

The transient receptor potential vanilloid 1 (TRPV1) is well-established in neuronal function, yet its role in immune reactions remains enigmatic. The conflicting data on its inflammatory role, suggesting both pro-inflammatory and anti-inflammatory effects upon TRPV1 stimulation in immune cells, adds complexity. To unravel TRPV1 immunomodulatory mechanisms, we investigated how the TRPV1 agonist capsaicin influences lipopolysaccharide (LPS)-induced pro-inflammatory macrophage phenotypes.

RESULTS

Changes in the surface molecules, cytokine production, and signaling cascades linked to the phenotype of M1 or M2 macrophages of the J774 macrophage cell line and bone marrow-derived macrophages, treated with capsaicin before or after the LPS-induced inflammatory reaction were determined. The functional capacity of macrophages was also assessed by infecting the stimulated macrophages with the intracellular parasite Leishmania mexicana.

CONCLUSION

Our findings reveal that TRPV1 activation yields distinct macrophage responses influenced by the inflammatory context. LPS pre-treatment followed by capsaicin activation prompted increased calcium influx, accompanied by a shift toward an anti-inflammatory M2b-like polarization state.

NF-κB-Signaling-Targeted Immunomodulatory Nanoparticle with Photothermal and Quorum-Sensing Inhibition Effects for Efficient Healing of Biofilm-Infected Wounds

The development of therapeutics with high antimicrobial activity and immunomodulatory effects is urgently needed for the treatment of infected wounds due to the increasing danger posed by recalcitrant-infected wounds. In this study, we developed light-controlled antibacterial, photothermal, and immunomodulatory biomimetic N/hPDA@M nanoparticles (NPs). This nanoplatform was developed by loading flavonoid naringenin onto hollow mesoporous polydopamine NPs in a π-π-stacked configuration and encasing them with macrophage membranes. First, our N/hPDA@M NPs efficiently neutralized inflammatory factors present within the wound microenvironment by the integration of macrophage membranes. Afterward, the N/hPDA@M NPs effectively dismantled bacterial biofilms through a combination of the photothermal properties of PDA and the quorum sensing inhibitory effects of naringenin. It is worth noting that N/hPDA@M NPs near-infrared-enhanced release of naringenin exhibited specificity toward the NF-κB-signaling pathway, effectively mitigating the inflammatory response. This innovative design not only conferred remarkable antibacterial properties upon the N/hPDA@M NPs but also endowed them with the capacity to modulate inflammatory responses, curbing excessive inflammation and steering macrophage polarization toward the M2 phenotype. As a result, this multifaceted approach significantly contributes to expediting the healing process of infected skin wounds.

The mysterious association between adiponectin and endometriosis

Adiponectin is a pleiotropic cytokine predominantly derived from adipose tissue. In addition to its role in regulating energy metabolism, adiponectin may also be related to estrogen-dependent diseases, and many studies have confirmed its involvement in mediating diverse biological processes, including apoptosis, autophagy, inflammation, angiogenesis, and fibrosis, all of which are related to the pathogenesis of endometriosis. Although many researchers have reported low levels of adiponectin in patients with endometriosis and suggested that it may serve as a protective factor against the development of the disease. Therefore, the purpose of this review was to provide an up-to-date summary of the roles of adiponectin and its downstream cytokines and signaling pathways in the aforementioned biological processes. Further systematic studies on the molecular and cellular mechanisms of action of adiponectin may provide novel insights into the pathophysiology of endometriosis as well as potential therapeutic targets.

The effect of macrophages and their exosomes in ischemic heart disease

Ischemic heart disease (IHD) is a leading cause of disability and death worldwide, with immune regulation playing a crucial role in its pathogenesis. Various immune cells are involved, and as one of the key immune cells residing in the heart, macrophages play an indispensable role in the inflammatory and reparative processes during cardiac ischemia. Exosomes, extracellular vesicles containing lipids, nucleic acids, proteins, and other bioactive molecules, have emerged as important mediators in the regulatory functions of macrophages and hold promise as a novel therapeutic target for IHD. This review summarizes the regulatory mechanisms of different subsets of macrophages and their secreted exosomes during cardiac ischemia over the past five years. It also discusses the current status of clinical research utilizing macrophages and their exosomes, as well as strategies to enhance their therapeutic efficacy through biotechnology. The aim is to provide valuable insights for the treatment of IHD.

Macrophage polarization in rheumatoid arthritis: signaling pathways, metabolic reprogramming, and crosstalk with synovial fibroblasts

Rheumatoid arthritis (RA) is a chronic autoimmune disease characterized by persistent synovial inflammation and progressive joint destruction. Macrophages are key effector cells that play a central role in RA pathogenesis through their ability to polarize into distinct functional phenotypes. An imbalance favoring pro-inflammatory M1 macrophages over anti-inflammatory M2 macrophages disrupts immune homeostasis and exacerbates joint inflammation. Multiple signaling pathways, including Notch, JAK/STAT, NF-κb, and MAPK, regulate macrophage polarization towards the M1 phenotype in RA. Metabolic reprogramming also contributes to this process, with M1 macrophages prioritizing glycolysis while M2 macrophages utilize oxidative phosphorylation. Redressing this imbalance by modulating macrophage polarization and metabolic state represents a promising therapeutic strategy. Furthermore, complex bidirectional interactions exist between synovial macrophages and fibroblast-like synoviocytes (FLS), forming a self-perpetuating inflammatory loop. Macrophage-derived factors promote aggressive phenotypes in FLS, while FLS-secreted mediators contribute to aberrant macrophage activation. Elucidating the signaling networks governing macrophage polarization, metabolic adaptations, and crosstalk with FLS is crucial to developing targeted therapies that can restore immune homeostasis and mitigate joint pathology in RA.

Injectable hydrogels activated with copper sulfide nanoparticles for enhancing spatiotemporal sterilization and osteogenesis in periodontal therapy

Developing biomaterials capable of promoting bone regeneration in bacteria-infected sites is of utmost urgency for periodontal disease therapies. Here we produce a hybrid hydrogel by integrating CuS nanoparticles (CuSNPs), which could kill bacteria through photothermal therapy (PTT) triggered by a near infrared (NIR) light, and a gelatin methacryloyl (GelMA) hydrogel, which is injectable and biocompatible. Specifically, CuSNPs were precipitated by chitosan (CS) firstly, then grafted with methacrylic anhydride (MA) to form CuSNP@CS-MA, which was photo-crosslinked with GelMA to synthesize hybrid hydrogels (GelMA/CuSNP). The hybrid hydrogels exhibited a broad-spectrum antibacterial property that could be spatiotemprorally manipulated through applying a NIR light. Their mechanical properties were adjustable by controlling the concentration of CuSNPs, enabling the hydrogels to become more adapted to the oral diseases. Meanwhile, the hybrid hydrogels showed good cytocompatibility in vitro and improved hemostasis in vivo. Moreover, they accelerated alveolar osteogenesis and vascular genesis, successfully treating periodontis in four weeks in a rat model. GelMA/CuSNP hydrogels showed a broad-spectrum sterilization ability via PTT in vitro and outstanding antibacterial property in vivo, suggesting that the hybrid hydrogels could function in the challenging, bacteria-rich, oral environment. Such injectable hybrid hydrogels, capable of achieving both facilitated osteogenesis and NIR-inducible sterilization, represent a new biomaterial for treating periodontitis.

Recent advances in potential targets for myocardial ischemia reperfusion injury: Role of macrophages

Myocardial ischemia-reperfusion injury (MIRI) is a complex process that occurs when blood flow is restored after myocardium infarction (MI) with exacerbated tissue damage. Macrophages, essential cell type of the immune response, play an important role in MIRI. Macrophage subpopulations, namely M1 and M2, are distinguished by distinct phenotypes and functions. In MIRI, macrophages infiltrate in infarcted area, shaping the inflammatory response and influencing tissue healing. Resident cardiac macrophages interact with monocyte-derived macrophages in MIRI, and influence injury progression. Key factors including chemokines, cytokines, and toll-like receptors modulate macrophage behavior in MIRI. This review aims to address recent findings on the classification and the roles of macrophages in the myocardium, spanning from MI to subsequent MIRI, and highlights various signaling pathways implicated in macrophage polarization underlining the complexity of MIRI. This article will shed light on developing advanced therapeutic strategies for MIRI management.

Role of microglia/macrophage polarisation in intraocular diseases (Review)

Macrophages form a crucial component of the innate immune system, and their activation is indispensable for various aspects of immune and inflammatory processes, tissue repair, and maintenance of the balance of the body's state. Macrophages are found in all ocular tissues, spanning from the front surface, including the cornea, to the posterior pole, represented by the choroid/sclera. The neural retina is also populated by specialised resident macrophages called microglia. The plasticity of microglia/macrophages allows them to adopt different activation states in response to changes in the tissue microenvironment. When exposed to various factors, microglia/macrophages polarise into distinct phenotypes, each exhibiting unique characteristics and roles. Furthermore, extensive research has indicated a close association between microglia/macrophage polarisation and the development and reversal of various intraocular diseases. The present article provides a review of the recent findings on the association between microglia/macrophage polarisation and ocular pathological processes (including autoimmune uveitis, optic neuritis, sympathetic ophthalmia, retinitis pigmentosa, glaucoma, proliferative vitreoretinopathy, subretinal fibrosis, uveal melanoma, ischaemic optic neuropathy, retinopathy of prematurity and choroidal neovascularization). The paradoxical role of microglia/macrophage polarisation in retinopathy of prematurity is also discussed. Several studies have shown that microglia/macrophages are involved in the pathology of ocular diseases. However, it is required to further explore the relevant mechanisms and regulatory processes. The relationship between the functional diversity displayed by microglia/macrophage polarisation and intraocular diseases may provide a new direction for the treatment of intraocular diseases.

Tumor-Associated Senescent Macrophages, Their Markers, and Their Role in Tumor Microenvironment

Tumor-associated macrophages (TAMs) are an important component of the tumor microenvironment (TME) and the most abundant population of immune cells infiltrating a tumor. TAMs can largely determine direction of anti-tumor immune response by promoting it or, conversely, contribute to formation of an immunosuppressive TME that allows tumors to evade immune control. Through interactions with tumor cells or other cells in the microenvironment and, as a result of action of anti-cancer therapy, macrophages can enter senescence. In this review, we have attempted to summarize information available in the literature on the role of senescent macrophages in tumors. With the recent development of senolytic therapeutic strategies aimed at removing senescent cells from an organism, it seems important to discuss functions of the senescent macrophages and potential role of the senolytic drugs in reprogramming TAMs to enhance anti-tumor immune response and improve efficacy of cancer treatment.

Monocytes and macrophages: Origin, homing, differentiation, and functionality during inflammation

Monocytes and macrophages are essential components of innate immune system and have versatile roles in homeostasis and immunity. These phenotypically distinguishable mononuclear phagocytes play distinct roles in different stages, contributing to the pathophysiology in various forms making them a potentially attractive therapeutic target in inflammatory conditions. Several pieces of evidence have supported the role of different cell surface receptors expressed on these cells and their downstream signaling molecules in initiating and perpetuating the inflammatory response. In this review, we discuss the current understanding of the monocyte and macrophage biology in inflammation, highlighting the role of chemoattractants, inflammasomes, and integrins in the function of monocytes and macrophages during events of inflammation. This review also covers the recent therapeutic interventions targeting these mononuclear phagocytes at the cellular and molecular levels.

The Role of Copper-Induced M2 Macrophage Polarization in Protecting Cartilage Matrix in Osteoarthritis

BACKGROUND The pathological mechanism of osteoarthritis is still unclear. The regulation of the immune microenvironment has been of growing interest in the progression and treatment of osteoarthritis. Macrophages with different phenotypes, producing different cytokines, have been linked to the mechanism of cartilage injury in osteoarthritis. Copper ions play a role in the immune response and are involved in the pathological mechanisms of osteoarthritis by affecting the metabolism of the cartilage matrix. Bioactive glass (BG) is an osteogenic material with superior biocompatibility. Here, we report on the regulatory behavior of macrophages using a copper-based composite BG material. MATERIAL AND METHODS Cu-BGC powder was prepared by sol-gel method, and scaffolds were fabricated and characterized using 3D printing. Macrophage cultures grown with Cu-BGC were examined for cell culture and proliferation. The effect of Cu-BGC on the degradation metabolism of chondrocytes, cultured in the environment of inflammatory cytokine IL-1ß, was determined. In addition, the morphology of macrophages, secretion of inflammatory cytokines, and expression of surface markers were examined. RESULTS The results show that Cu-BGC promotes macrophage proliferation at a range of concentrations and increases the secretion of anti-inflammatory cytokines while inhibiting proinflammatory cytokines. At the same time, M2-type cell surface markers are definitely expressed and the morphology of macrophages is altered. In addition, Cu-BGC inhibited the degradation metabolism of chondrocytes in the inflammatory environment induced by IL-1ß. CONCLUSIONS These results suggest that Cu-BGC induced macrophage polarization into an M2 type anti-inflammatory phenotype, and inhibition of immune injury response may play a role in delaying cartilage matrix damage in osteoarthritis.

Research progress on the role of macrophages in acne and regulation by natural plant products

Acne vulgaris is one of the most common skin diseases. The current understanding of acne primarily revolves around inflammatory responses, sebum metabolism disorders, aberrant hormone and receptor expression, colonization by Cutibacterium acnes, and abnormal keratinization of follicular sebaceous glands. Although the precise mechanism of action remains incompletely understood, it is plausible that macrophages exert an influence on these pathological features. Macrophages, as a constituent of the human innate immune system, typically manifest distinct phenotypes across various diseases. It has been observed that the polarization of macrophages toward the M1 phenotype plays a pivotal role in the pathogenesis of acne. In recent years, extensive research on acne has revealed an increasing number of natural remedies exhibiting therapeutic efficacy through the modulation of macrophage polarization. This review investigates the role of cutaneous macrophages, elucidates their potential significance in the pathogenesis of acne, a prevalent chronic inflammatory skin disorder, and explores the therapeutic mechanisms of natural plant products targeting macrophages. Despite these insights, the precise role of macrophages in the pathogenesis of acne remains poorly elucidated. Subsequent investigations in this domain will further illuminate the pathogenesis of acne and potentially offer guidance for identifying novel therapeutic targets for this condition.

Tumor-associated macrophages affect the treatment of lung cancer

As one of the most common malignant tumors in the world, lung cancer has limited benefits for patients despite its diverse treatment methods due to factors such as personalized medicine targeting histological type, immune checkpoint expression, and driver gene mutations. The high mortality rate of lung cancer is partly due to the immune-suppressive which limits the effectiveness of anti-cancer drugs and induces tumor cell resistance. The currently widely recognized TAM phenotypes include the anti-tumor M1 and pro-tumor M2 phenotypes. M2 macrophages promote the formation of an immune-suppressive microenvironment and hinder immune cell infiltration, thereby inhibiting activation of the anti-tumor immune system and aiding tumor cells in resisting treatment. Analyzing the relationship between different treatment methods and macrophages in the TME can help us better understand the impact of TAMs on lung cancer and confirm the feasibility of targeted TAM therapy. Targeting TAMs to reduce the M2/M1 ratio and reverse the immune-suppressive microenvironment can improve the clinical efficacy of conventional treatment methods and potentially open up more efficient combination treatment strategies, maximizing the benefit for lung cancer patients.

Targeting Macrophages: Therapeutic Approaches in Diabetic Kidney Disease

Diabetes is not solely a metabolic disorder but also involves inflammatory processes. The immune response it incites is a primary contributor to damage in target organs. Research indicates that during the initial phases of diabetic nephropathy, macrophages infiltrate the kidneys alongside lymphocytes, initiating a cascade of inflammatory reactions. The interplay between macrophages and other renal cells is pivotal in the advancement of kidney disease within a hyperglycemic milieu. While M1 macrophages react to the inflammatory stimuli induced by elevated glucose levels early in the disease progression, their subsequent transition to M2 macrophages, which possess anti-inflammatory and tissue repair properties, also contributes to fibrosis in the later stages of nephropathy by transforming into myofibroblasts. Comprehending the diverse functions of macrophages in diabetic kidney disease and regulating their activity could offer therapeutic benefits for managing this condition.

Spatially resolved immune exhaustion within the alloreactive microenvironment predicts liver transplant rejection

Allograft rejection is common following clinical organ transplantation, but defining specific immune subsets mediating alloimmunity has been elusive. Calcineurin inhibitor dose escalation, corticosteroids, and/or lymphocyte depleting antibodies have remained the primary options for treatment of clinical rejection episodes. Here, we developed a highly multiplexed imaging mass cytometry panel to study the immune response in archival biopsies from 79 liver transplant (LT) recipients with either no rejection (NR), acute T cell-mediated rejection (TCMR), or chronic rejection (CR). This approach generated a spatially resolved proteomic atlas of 461,816 cells (42 phenotypes) derived from 96 pathologist-selected regions of interest. Our analysis revealed that regulatory (HLADR+ Treg) and PD1+ T cell phenotypes (CD4+ and CD8+ subsets), combined with variations in M2 macrophage polarization, were a unique signature of active TCMR. These data provide insights into the alloimmune microenvironment in clinical LT, including identification of potential targets for focused immunotherapy during rejection episodes and suggestion of a substantial role for immune exhaustion in TCMR.