Transcriptional profiling of the human monocyte-to-macrophage differentiation and polarization: new molecules and patterns of gene expression

Novel hypermorphic variants in IRF2BP2 identified in patients with common variable immunodeficiency and autoimmunity

The interferon regulatory factor 2 binding protein 2 (IRF2BP2) is a transcriptional regulator, functioning a transcriptional corepressor by interacting with the interferon regulatory factor-2. The ubiquitous expression of IRF2BP2 by diverse cell types and tissues suggests its potential involvement in different cell signalling pathways. Variants inIRF2BP2have been recently identified to cause familial common variable immunodeficiency (CVID) characterized by immune dysregulation. This study investigated three rare novel variants inIRF2BP2, identified in patients with primary antibody deficiency and autoimmunity by whole exome-sequencing (WES). Following transient overexpression of EGFP-fused mutants in HEK293 cells and transfection in Jurkat cell lines, we used fluorescence microscopy, real-time PCR and Western blotting to analyze their effects on IRF2BP2 expression, subcellular localization, nuclear translocation of IRF2, and the transcriptional activation of NFκB1(p50). We found altered IRF2BP2 mRNA and protein expression levels in the mutants compared to the wild type after IRF2BP2 overexpression. In confocal fluorescence microscopy, variants in the C-terminal RING finger domain showed an irregular aggregate formation and distribution instead of the expected nuclear localization compared to the variants in the N-terminal zinc finger domain and their wildtype counterpart. Immunoblotting revealed an impaired IRF2 and NFκB1 (p50) nuclear localization in the mutants compared to the IRF2BP2 wildtype counterpart. LPS stimulation reduced IRF2BP2 mRNA expression in the variants compared to the wild type. Our findings significantly contribute to understanding the clinical significance of IRF2BP2 mutations in the pathogenesis of immunodeficiency and immune dysregulation. We observed impairment of the nuclear translocation of IRF2 and NFκB1 (p50) due to the upregulation of IRF2BP2, potentially affecting specific gene expressions involved in immune regulation.

Exploring the molecular mechanisms and shared potential drugs between rheumatoid arthritis and arthrofibrosis based on large language model and synovial microenvironment analysis

Rheumatoid arthritis (RA) and arthrofibrosis (AF) are both chronic synovial hyperplasia diseases that result in joint stiffness and contractures. They shared similar symptoms and many common features in pathogenesis. Our study aims to perform a comprehensive analysis between RA and AF and identify novel drugs for clinical use. Based on the text mining approaches, we performed a correlation analysis of 12 common joint diseases including arthrofibrosis, gouty arthritis, infectious arthritis, juvenile idiopathic arthritis, osteoarthritis, post infectious arthropathies, post traumatic osteoarthritis, psoriatic arthritis, reactive arthritis, rheumatoid arthritis, septic arthritis, and transient arthritis. 5 bulk sequencing datasets and 4 single-cell sequencing datasets of RA and AF were integrated and analyzed. A novel drug repositioning method was found for drug screening, and text mining approaches were used to verify the identified drugs. RA and AF performed the highest gene similarity (0.77) and functional ontology similarity (0.84) among all 12 joint diseases. We figured out that they share the same key pathogenic cell including CD34 + sublining fibroblasts (CD34-SLF) and DKK3 + sublining fibroblasts (DKK3-SLF). Potential therapeutic target database (PTTD) was established with the differential expressed genes (DEGs) of these key pathogenic cells. Based on the PTTD, 15 potential drugs for AF and 16 potential drugs for RA were identified. This work provides a new perspective on AF and RA study which enhances our understanding of their pathogenesis. It also shed light on their underlying mechanism and open new avenues for drug repositioning studies.

The improvement of inflammatory infiltration and pregnancy outcome in mice with recurrent spontaneous abortion by human amniotic mesenchymal stem cells

Recurrent spontaneous abortion is thought to be mostly triggered by immune-related causes. Mesenchymal stem cells, which exhibit the traits of multi-directional differentiation capacity and low immunogenicity, have recently been recommended as a viable treatment for spontaneous abortion-prone mice to increase the success of pregnancy. Amniotic membrane tissue is a byproduct of pregnancy and delivery that has a wide range of potential uses due to its easy access to raw materials and little ethical constraints. To construct an abortion-prone mouse model for this investigation, CBA/J female mice were coupled with male DBA/2 mice, while CBA/J female mice were paired with male BALB/c mice as a control. The identical volume of human amniotic mesenchymal stem cells or phosphate buffer was injected intraperitoneally on the 4.5th day of pregnancy. CBA/J female mice were sacrificed by cervical dislocation on the 13.5th day of pregnancy, the embryo absorption rate was calculated, and the uterus, decidua tissues and placenta were gathered for examination. Through detection, it was discovered that human amniotic mesenchymal stem cells significantly increased the expression of interleukin 10 and transforming growth factor beta, while they significantly decreased the expression of interleukin 1 beta and interleukin 6, improved vascular formation and angiogenesis, and minimized the embryo absorption rate and inflammatory cell infiltration in the recurrent spontaneous abortion + human amniotic mesenchymal stem cells group. In any case, human amniotic mesenchymal stem cells regulate inflammatory factors and cell balance at the maternal-fetal interface, which result in a reduction in the rate of embryo absorption and inflammatory infiltration and provide an innovative perspective to the clinical therapy of recurrent spontaneous abortion.

The role of macrophage plasticity in neurodegenerative diseases

Tissue-resident macrophages and recruited macrophages play pivotal roles in innate immunity and the maintenance of brain homeostasis. Investigating the involvement of these macrophage populations in eliciting pathological changes associated with neurodegenerative diseases has been a focal point of research. Dysregulated states of macrophages can compromise clearance mechanisms for pathological proteins such as amyloid-β (Aβ) in Alzheimer's disease (AD) and TDP-43 in Amyotrophic lateral sclerosis (ALS). Additionally, recent evidence suggests that abnormalities in the peripheral clearance of pathological proteins are implicated in the pathogenesis and progression of neurodegenerative diseases. Furthermore, numerous genome-wide association studies have linked genetic risk factors, which alter the functionality of various immune cells, to the accumulation of pathological proteins. This review aims to unravel the intricacies of macrophage biology in both homeostatic conditions and neurodegenerative disorders. To this end, we initially provide an overview of the modifications in receptor and gene expression observed in diverse macrophage subsets throughout development. Subsequently, we outlined the roles of resident macrophages and recruited macrophages in neurodegenerative diseases and the progress of targeted therapy. Finally, we describe the latest advances in macrophage imaging methods and measurement of inflammation, which may provide information and related treatment strategies that hold promise for informing the design of future investigations and therapeutic interventions.

Targeting Macrophage Phenotypes and Metabolism as Novel Therapeutic Approaches in Atherosclerosis and Related Cardiovascular Diseases

PURPOSE OF THE REVIEW

Macrophage accumulation and activation function as hallmarks of atherosclerosis and have complex and intricate dynamics throughout all components and stages of atherosclerotic plaques. In this review, we focus on the regulatory roles and underlying mechanisms of macrophage phenotypes and metabolism in atherosclerosis. We highlight the diverse range of macrophage phenotypes present in atherosclerosis and their potential roles in progression and regression of atherosclerotic plaque. Furthermore, we discuss the challenges and opportunities in developing therapeutic strategies for preventing and treating atherosclerotic cardiovascular disease.

RECENT FINDINGS

Dysregulation of macrophage polarization between the proinflammatory M1 and anti-inflammatory M2 phenotypealters the immuno-inflammatory response during atherosclerosis progression, leading to plaque initiation, growth, and ultimately rupture. Altered metabolism of macrophage is a key feature for their function and the subsequent progression of atherosclerotic cardiovascular disease. The immunometabolism of macrophage has been implicated to macrophage activation and metabolic rewiring of macrophages within atherosclerotic lesions, thereby shifting altered macrophage immune-effector and tissue-reparative function. Targeting macrophage phenotypes and metabolism are potential therapeutic strategies in the prevention and treatment of atherosclerosis and atherosclerotic cardiovascular diseases. Understanding the precise function and metabolism of specific macrophage subsets and their contributions to the composition and growth of atherosclerotic plaques could reveal novel strategies to delay or halt development of atherosclerotic cardiovascular diseases and their associated pathophysiological consequences. Identifying biological stimuli capable of modulating macrophage phenotypes and metabolism may lead to the development of innovative therapeutic approaches for treating patients with atherosclerosis and coronary artery diseases.

Modulation of Breast Cancer Cell Apoptosis and Macrophage Polarization by Mistletoe Lectin in 2D and 3D Models

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

Stimuli-Mediated Macrophage Switching, Unraveling the Dynamics at the Nanoplatforms-Macrophage Interface

Macrophages play an essential role in immunotherapy and tissue regeneration owing to their remarkable plasticity and diverse functions. Recent bioengineering developments have focused on using external physical stimuli such as electric and magnetic fields, temperature, and compressive stress, among others, on micro/nanostructures to induce macrophage polarization, thereby increasing their therapeutic potential. However, it is difficult to find a concise review of the interaction between physical stimuli, advanced micro/nanostructures, and macrophage polarization. This review examines the present research on physical stimuli-induced macrophage polarization on micro/nanoplatforms, emphasizing the synergistic role of fabricated structure and stimulation for advanced immunotherapy and tissue regeneration. A concise overview of the research advancements investigating the impact of physical stimuli, including electric fields, magnetic fields, compressive forces, fluid shear stress, photothermal stimuli, and multiple stimulations on the polarization of macrophages within complex engineered structures, is provided. The prospective implications of these strategies in regenerative medicine and immunotherapeutic approaches are highlighted. This review will aid in creating stimuli-responsive platforms for immunomodulation and tissue regeneration.

Natural product/diet-based regulation of macrophage polarization: Implications in treatment of inflammatory-related diseases and cancer

Macrophages are phagocytic cells with important physiological functions, including the digestion of cellular debris, foreign substances, and microbes, as well as tissue development and homeostasis. The tumor microenvironment (TME) shapes the aggressiveness of cancer, and the biological and cellular interactions in this complicated space can determine carcinogenesis. TME can determine the progression, biological behavior, and therapy resistance of human cancers. The macrophages are among the most abundant cells in the TME, and their functions and secretions can determine tumor progression. The education of macrophages to M2 polarization can accelerate cancer progression, and therefore, the re-education and reprogramming of these cells is promising. Moreover, macrophages can cause inflammation in aggravating pathological events, including cardiovascular diseases, diabetes, and neurological disorders. The natural products are pleiotropic and broad-spectrum functional compounds that have been deployed as ideal alternatives to conventional drugs in the treatment of cancer. The biological and cellular interactions in the TME can be regulated by natural products, and for this purpose, they enhance the M1 polarization of macrophages, and in addition to inhibiting proliferation and invasion, they impair the chemoresistance. Moreover, since macrophages and changes in the molecular pathways in these cells can cause inflammation, the natural products impair the pro-inflammatory function of macrophages to prevent the pathogenesis and progression of diseases. Even a reduction in macrophage-mediated inflammation can prevent organ fibrosis. Therefore, natural product-mediated macrophage targeting can alleviate both cancerous and non-cancerous diseases.

Analysis of clinical cure outcome, macrophages number, cytokines levels and expression of annexin-A1 in the cutaneous infection in patients with Leishmania braziliensis

BACKGROUND

Leishmania braziliensis, a protozoan prevalent in Brazil, is the known causative agent of cutaneous leishmaniasis (CL). The activation of M1 macrophages is a pivotal factor in the host's ability to eliminate the parasite, whereas M2 macrophages may facilitate parasite proliferation. This study analyzed the clinical outcomes of CL and the patients' immunological profiles, focusing on the prevalence of M1 and M2 macrophages, cytokine production, and annexin-A1 (ANXA1) expression in the lesion.

METHODS

Data were obtained by polymerase chain reaction (PCR) and histopathological, immunofluorescence, and cytokine analyses.

RESULTS

Patients with exudative and cellular reaction-type (ECR)-type lesions that healed within 90 days showed a significant increase in M1. Conversely, patients with ECR and exudative and granulomatous reaction (EGR)types, who healed within 180 days, showed an elevated number of M2. Cytokines interferon (IFN)-γ and tumor necrosis factor (TNF)-α were higher in ECR lesions that resolved within 90 days (P<0.05). In contrast, IL-9 and IL-10 levels significantly increased in both ECR and EGR lesions that healed after 180 days (P<0.001). The production of IL-21, IL-23 and TGF-β was increased in patients with ECR or EGR lesions that healed after 180 days (P<0.05). The expression of ANXA1 was higher in M2 within ECR-type lesions in patients who healed after 180 days (P<0.05).

CONCLUSIONS

These findings suggest that the infectious microenvironment induced by L. braziliensis affects the differentiation of M1 and M2 macrophages, cytokine release, and ANXA1 expression, thereby influencing the healing capacity of patients. Therefore, histopathological and immunological investigations may improve the selection of CL therapy.

The choroid plexus synergizes with immune cells during neuroinflammation

The choroid plexus (ChP) is a vital brain barrier and source of cerebrospinal fluid (CSF). Here, we use longitudinal two-photon imaging in awake mice and single-cell transcriptomics to elucidate the mechanisms of ChP regulation of brain inflammation. We used intracerebroventricular injections of lipopolysaccharides (LPS) to model meningitis in mice and observed that neutrophils and monocytes accumulated in the ChP stroma and surged across the epithelial barrier into the CSF. Bi-directional recruitment of monocytes from the periphery and, unexpectedly, macrophages from the CSF to the ChP helped eliminate neutrophils and repair the barrier. Transcriptomic analyses detailed the molecular steps accompanying this process and revealed that ChP epithelial cells transiently specialize to nurture immune cells, coordinating their recruitment, survival, and differentiation as well as regulation of the tight junctions that control the permeability of the ChP brain barrier. Collectively, we provide a mechanistic understanding and a comprehensive roadmap of neuroinflammation at the ChP brain barrier.

Monitoring melanoma patients on treatment reveals a distinct macrophage population driving targeted therapy resistance

Resistance to targeted therapy remains a major clinical challenge in melanoma. To uncover resistance mechanisms, we perform single-cell RNA sequencing on fine-needle aspirates from resistant and responding tumors of patients undergoing BRAFi/MEKi treatment. Among the genes most prominently expressed in resistant tumors is POSTN, predicted to signal to a macrophage population associated with targeted therapy resistance (TTR). Accordingly, tumors from patients with fast disease progression after therapy exhibit high POSTN expression levels and high numbers of TTR macrophages. POSTN polarizes human macrophages toward a TTR phenotype and promotes resistance to targeted therapy in a melanoma mouse model, which is associated with a phenotype change in intratumoral macrophages. Finally, polarized TTR macrophages directly protect human melanoma cells from MEKi-induced killing via CD44 receptor expression on melanoma cells. Thus, interfering with the protective activity of TTR macrophages may offer a strategy to overcome resistance to targeted therapy in melanoma.

In vitro functional assays to assess the reciprocal interplay between tumor cells and macrophages

Tumor-associated macrophages (TAMs) are integral components of the tumor microenvironment. They are involved in various aspects of tumor cell biology, driving pathological processes such as tumor cell proliferation, metastasis, immunosuppression, and resistance to therapy. TAMs exert their tumorigenic effects by secreting growth factors, cytokines/chemokines, metabolites, and other soluble bioactive molecules. These mediators directly promote tumor cell proliferation and modulate interactions with immune and stromal cells, facilitating further tumor growth. As research into therapies targeting TAMs intensifies, there is a growing need for reliable methods to comprehend the impact of TAMs on cancer progression and to validate novel therapeutics directed at TAMs. The traditional "M1-M2" macrophage classification based on transcriptional profiles of TAMs is not only too simplistic to describe their physiological roles, it also does not explain differences observed between mouse and human macrophages. In this context, methods that assess how TAMs influence tumor or immune cells, either through direct contact or the release of soluble factors, offer a more promising approach. We describe here comprehensive protocols for in vitro functional assays to study TAMs, specifically regarding their impact on the growth of lung cancer cells. We have applied these methods to both mouse and human macrophages, achieving similar outcomes in promoting the proliferation of cancer cells. This methodology can serve as a standardized approach for testing novel therapeutic approaches, targeting TAMs with novel immunotherapeutic compounds, or utilizing gene-editing techniques. Taken together, the described methodology may contribute to our understanding of complex macrophage-tumor interactions and support the development of innovative therapeutic 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.

Dysregulated ribosome quality control in human diseases

Precise regulation of mRNA translation is of fundamental importance for maintaining homeostasis. Conversely, dysregulated general or transcript-specific translation, as well as abnormal translation events, have been linked to a multitude of diseases. However, driven by the misconception that the transient nature of mRNAs renders their abnormalities inconsequential, the importance of mechanisms that monitor the quality and fidelity of the translation process has been largely overlooked. In recent years, there has been a dramatic shift in this paradigm, evidenced by several seminal discoveries on the role of a key mechanism in monitoring the quality of mRNA translation - namely, Ribosome Quality Control (RQC) - in the maintenance of homeostasis and the prevention of diseases. Here, we will review recent advances in the field and emphasize the biological significance of the RQC mechanism, particularly its implications in human diseases.

Sema-3E/PlexinD1 axis modulates dendritic cell phenotypes and functions: Current status and future implications

This comprehensive research review explores the complex interplay between the Sema-3E/PlexinD1 axis and dendritic cells (DCs), highlighting its critical role in immune modulation with implications for clinical application Critical regulators of immune responses Dendritic cells are central to adaptive immunity, and the Sema-3E /PlexinD1 axis emerges as a key modulator affecting their phenotypes and functions Review delineates the impact of this signaling axis on DC maturation, migration, antigen presentation, and cytokine production, unravels its multifaceted role in shaping the immune response. Recognizing the limitations and gaps in current knowledge, the study highlights the need for further studies to condition downstream signaling events and related information experienced by the Sema-3E/PlexinD1 axis emphasizes the clarity of the immune system. The review concludes by identifying opportunities for translation, focusing on therapeutic and diagnostic potential. It highlights the importance of collaborative, interdisciplinary efforts to address the challenges and harness the therapeutic and pathological potential of targeting the Sema-3E/PlexinD1 axis, thus opening the way for transformative advances in immunology and clinical medicine.

Regulation of macrophage polarization by targeted metabolic reprogramming for the treatment of lupus nephritis

Lupus nephritis (LN) is a severe and common manifestation of systemic lupus erythematosus (SLE) that is frequently identified with a poor prognosis. Macrophages play an important role in its pathogenesis. Different macrophage subtypes have different effects on lupus-affected kidneys. Based on their origin, macrophages can be divided into monocyte-derived macrophages (MoMacs) and tissue-resident macrophages (TrMacs). During nephritis, TrMacs develop a hybrid pro-inflammatory and anti-inflammatory functional phenotype, as they do not secrete arginase or nitric oxide (NO) when stimulated by cytokines. The infiltration of these mixed-phenotype macrophages is related to the continuous damage caused by immune complexes and exposure to circulating inflammatory mediators, which is an indication of the failure to resolve inflammation. On the other hand, MoMacs differentiate into M1 or M2 cells under cytokine stimulation. M1 macrophages are pro-inflammatory and secrete pro-inflammatory cytokines, while the M2 main phenotype is essentially anti-inflammatory and promotes tissue repair. Conversely, MoMacs undergo differentiation into M1 or M2 cells in response to cytokine stimulation. M1 macrophages are considered pro-inflammatory cells and secrete pro-inflammatory mediators, whereas the M2 main phenotype is primarily anti-inflammatory and promotes tissue repair. Moreover, based on cytokine expression, M2 macrophages can be further divided into M2a, M2b, and M2c phenotypes. M2a and M2c have anti-inflammatory effects and participate in tissue repair, while M2b cells have immunoregulatory and pro-inflammatory properties. Further, memory macrophages also have a role in the advancement of LN. Studies have demonstrated that the polarization of macrophages is controlled by multiple metabolic pathways, such as glycolysis, the pentose phosphate pathway, fatty acid oxidation, sphingolipid metabolism, the tricarboxylic acid cycle, and arginine metabolism. The changes in these metabolic pathways can be regulated by substances such as fish oil, polyenylphosphatidylcholine, taurine, fumaric acid, metformin, and salbutamol, which inhibit M1 polarization of macrophages and promote M2 polarization, thereby alleviating LN.

Unifying considerations and evidence of macrophage activation mosaicism through human CSF1R and M1/M2 genes

Addressing the mononuclear phagocyte system (MPS) and macrophage M1/M2 activation is important in diagnosing hematological disorders and inflammatory pathologies and designing therapeutic tools. CSF1R is a reliable marker to identify all circulating MPS cells and tissue macrophages in humans using a single surface protein. CSF1R permits the quantification and isolation of monocyte and dendritic cell (DC) subsets in conjunction with CD14, CD16, and CD1c and is stable across the lifespan and sexes in the absence of overt pathology. Beyond cell detection, measuring M1/M2 activation in humans poses challenges due to response heterogeneity, transient signaling, and multiple regulation steps for transcripts and proteins. MPS cells respond in a conserved manner to M1/M2 pathways such as interleukin-4 (IL-4), steroids, interferon-γ (IFNγ), and lipopolysaccharide (LPS), for which we propose an ad hoc modular gene expression tool. Signature analysis highlights macrophage activation mosaicism in experimental samples, an emerging concept that points to mixed macrophage activation states in pathology.

CCR7 and CD48 as Predicted Targets in Acute Rejection Related to M1 Macrophage after Pediatric Kidney Transplantation

Background

Kidney transplantation (KT) is the best treatment for end-stage renal disease. Although long and short-term survival rates for the graft have improved significantly with the development of immunosuppressants, acute rejection (AR) remains a major risk factor attacking the graft and patients. The innate immune response plays an important role in rejection. Therefore, our objective is to determine the biomarkers of congenital immunity associated with AR after KT and provide support for future research.

Materials and Methods

A differential expression genes (DEGs) analysis was performed based on the dataset GSE174020 from the NCBI gene Expression Synthesis Database (GEO) and then combined with the GSE5099 M1 macrophage-related gene identified in the Molecular Signatures Database. We then identified genes in DEGs associated with M1 macrophages defined as DEM1Gs and performed gene ontology (GO) and Kyoto Encyclopedia of Genomes (KEGG) enrichment analysis. Cibersort was used to analyze the immune cell infiltration during AR. At the same time, we used the protein-protein interaction (PPI) network and Cytoscape software to determine the key genes. Dataset, GSE14328 derived from pediatric patients, GSE138043 and GSE9493 derived from adult patients, were used to verify Hub genes. Additional verification was the rat KT model, which was used to perform HE staining, immunohistochemical staining, and Western Blot. Hub genes were searched in the HPA database to confirm their expression. Finally, we construct the interaction network of transcription factor (TF)-Hub genes and miRNA-Hub genes.

Results

Compared to the normal group, 366 genes were upregulated, and 423 genes were downregulated in the AR group. Then, 106 genes related to M1 macrophages were found among these genes. GO and KEGG enrichment analysis showed that these genes are mainly involved in cytokine binding, antigen binding, NK cell-mediated cytotoxicity, activation of immune receptors and immune response, and activation of the inflammatory NF-κB signaling pathway. Two Hub genes, namely CCR7 and CD48, were identified by PPI and Cytoscape analysis. They have been verified in external validation sets, originated from both pediatric patients and adult patients, and animal experiments. In the HPA database, CCR7 and CD48 are mainly expressed in T cells, B cells, macrophages, and tissues where these immune cells are distributed. In addition to immunoinfiltration, CD4+T, CD8+T, NK cells, NKT cells, and monocytes increased significantly in the AR group, which was highly consistent with the results of Hub gene screening. Finally, we predicted that 19 TFs and 32 miRNAs might interact with the Hub gene.

Conclusions

Through a comprehensive bioinformatic analysis, our findings may provide predictive and therapeutic targets for AR after KT.

Targeting Macrophage Polarization in Infectious Diseases: M1/M2 Functional Profiles, Immune Signaling and Microbial Virulence Factors

INTRODUCTION

An event of increasing interest during host-pathogen interactions is the polarization of patrolling/naive monocytes (MOs) into macrophage subsets (MФs). Therapeutic strategies aimed at modulating this event are under investigation.

METHODS

This review focuses on the mechanisms of induction/development and profile of MФs polarized toward classically proinflammatory (M1) or alternatively anti-inflammatory (M2) phenotypes in response to bacteria, fungi, parasites, and viruses.

RESULTS AND DISCUSSION

It highlights nuclear, cytoplasmic, and cell surface receptors (pattern recognition receptors/PPRs), microenvironmental mediators, and immune signaling. MФs polarize into phenotypes: M1 MФs, activated by IFN-γ, pathogen-associated molecular patterns (PAMPs, e.g. lipopolysaccharide) and membrane-bound PPRs ligands (TLRs/CLRs ligands); or M2 MФs, induced by interleukins (ILs-4, -10 and -13), antigen-antibody complexes, and helminth PAMPs. Polarization toward M1 and M2 profiles evolve in a pathogen-specific manner, with or without canonicity, and can vary widely. Ultimately, this can result in varying degrees of host protection or more severe disease outcome. On the one hand, the host is driving effective MФs polarization (M1 or M2); but on the other hand, microorganisms may skew the polarization through virulence factors to increase pathogenicity. Cellular/genomic reprogramming also ensures plasticity of M1/M2 phenotypes. Because modulation of polarization can occur at multiple points, new insights and emerging perspectives may have clinical implications during the inflammation-to-resolution transition; translated into practical applications as for therapeutic/vaccine design target to boost microbicidal response (M1, e.g. triggering oxidative burst) with specifics PAMPs/IFN-γ or promote tissue repair (M2, increasing arginase activity) via immunotherapy.

Interleukin 27, Similar to Interferons, Modulates Gene Expression of Tripartite Motif (TRIM) Family Members and Interferes with Mayaro Virus Replication in Human Macrophages

BACKGROUND

The Tripartite motif (TRIM) family includes more than 80 distinct human genes. Their function has been implicated in regulating important cellular processes, including intracellular signaling, transcription, autophagy, and innate immunity. During viral infections, macrophages are key components of innate immunity that produce interferons (IFNs) and IL27. We recently published that IL27 and IFNs induce transcriptional changes in various genes, including those involved in JAK-STAT signaling. Furthermore, IL27 and IFNs share proinflammatory and antiviral pathways in monocyte-derived macrophages (MDMs), resulting in both common and unique expression of inflammatory factors and IFN-stimulated genes (ISGs) encoding antiviral proteins. Interestingly, many TRIM proteins have been recognized as ISGs in recent years. Although it is already very well described that TRIM expression is induced by IFNs, it is not fully understood whether TRIM genes are induced in macrophages by IL27. Therefore, in this study, we examined the effect of stimulation with IL27 and type I, II, and III IFNs on the mRNA expression profiles of TRIM genes in MDMs.

METHODS

We used bulk RNA-seq to examine the TRIM expression profile of MDMs treated with IFNs or IL27. Initially, we characterized the expression patterns of different TRIM subfamilies using a heatmap. Subsequently, a volcano plot was employed to identify commonly differentially expressed TRIM genes. Additionally, we conducted gene ontology analysis with ClueGO to explore the biological processes of the regulated TRIMs, created a gene-gene interaction network using GeneMANIA, and examined protein-protein interactions with the STRING database. Finally, RNA-seq data was validated using RT-qPCR. Furthermore, the effect of IL27 on Mayaro virus replication was also evaluated.

RESULTS

We found that IL27, similar to IFNs, upregulates several TRIM genes' expression in human macrophages. Specifically, we identified three common TRIM genes (TRIM19, 21, and 22) induced by IL27 and all types of human IFNs. Additionally, we performed the first report of transcriptional regulation of TRIM19, 21, 22, and 69 genes in response to IL27. The TRIMs involved a broad range of biological processes, including defense response to viruses, viral life cycle regulation, and negative regulation of viral processes. In addition, we observed a decrease in Mayaro virus replication in MDMs previously treated with IL27.

CONCLUSIONS

Our results show that IL27, like IFNs, modulates the transcriptional expression of different TRIM-family members involved in the induction of innate immunity and an antiviral response. In addition, the functional analysis demonstrated that, like IFN, IL27 reduced Mayaro virus replication in MDMs. This implies that IL27 and IFNs share many similarities at a functional level. Moreover, identifying distinct TRIM groups and their differential expressions in response to IL27 provides new insights into the regulatory mechanisms underlying the antiviral response in human macrophages.

Comprehensive analysis of lncRNA-associated ceRNA network reveals novel potential prognostic regulatory axes in glioblastoma multiforme

Deciphering the lncRNA-associated competitive endogenous RNA (ceRNA) network is essential in decoding glioblastoma multiforme (GBM) pathogenesis by regulating miRNA availability and controlling mRNA stability. This study aimed to explore novel biomarkers for GBM by constructing a lncRNA-miRNA-mRNA network. A ceRNA network in GBM was constructed using lncRNA, mRNA and miRNA expression profiles from the TCGA and GEO datasets. Seed nodes were identified by protein-protein interaction (PPI) network analysis of deregulated-mRNAs (DEmRNAs) in the ceRNA network. A lncRNA-miRNA-seed network was constructed by mapping the seed nodes into the preliminary ceRNA network. The impact of the seed nodes on the overall survival (OS) of patients was assessed by the GSCA database. Functional enrichment analysis of the deregulated-lncRNAs (DElncRNA) in the ceRNA network and genes interacting with OS-related genes in the PPI network were performed. Finally, the positive correlation between seed nodes and their associated lncRNAs and the expression level of these molecules in GBM tissue compared with normal samples was validated using the GEPIA database. Our analyzes revealed that three novel regulatory axes AL161785.1/miR-139-5p/MS4A6A, LINC02611/miR-139-5p/MS4A6A and PCED1B-AS1/miR-433-3p/MS4A6A may play essential roles in GBM pathogenesis. MS4A6A is upregulated in GBM and closely associated with shorter survival time of patients. We also identified that MS4A6A expression positively correlates with genes related to tumour-associated macrophages, which induce macrophage infiltration and immune suppression. The functional enrichment analysis demonstrated that DElncRNAs are mainly involved in neuroactive ligand-receptor interaction, calcium/MAPK signalling pathway, ribosome, GABAergic/Serotonergic/Glutamatergic synapse and immune system process. In addition, genes related to MS4A6A contribute to immune and inflammatory-related biological processes. Our findings provide novel insights to understand the ceRNA regulation in GBM and identify novel prognostic biomarkers or therapeutic targets.

ADP as a novel stimulus for NLRP3-inflammasome activation in mice fails to translate to humans

The NLRP3-inflammasome is a cytosolic multiprotein complex that triggers an inflammatory response to certain danger signals. Recently adenosine diphosphate (ADP) was found to activate the NLRP3-inflammasome in murine macrophages via the P2Y1 receptor. Blockade of this signaling pathway reduced disease severity in a murine colitis-model. However, the role of the ADP/P2Y1-axis has not yet been studied in humans. This present study confirmed ADP-dependent NLRP3-inflammasome activation in murine macrophages, but found no evidence for a role of ADP in inflammasome activation in humans. We investigated the THP1 cell line as well as primary monocytes and further looked at macrophages. Although all cells express the three human ADP-receptors P2Y1, P2Y12 and P2Y13, independent of priming, neither increased ASC-speck formation could be detected with flow cytometry nor additional IL-1β release be found in the culture supernatant of ADP stimulated cells. We now show for the first time that the responsiveness of monocytes and macrophages to ADP as well as the regulation of its purinergic receptors is very much dependent on the species. Therefore the signaling pathway found to contribute to colitis in mice is likely not applicable to humans.

Single-cell and spatial transcriptomics analysis of human adrenal aging

OBJECTIVE

The human adrenal cortex comprises three functionally and structurally distinct layers that produce layer-specific steroid hormones. With aging, the human adrenal cortex undergoes functional and structural alteration or "adrenal aging", leading to the unbalanced production of steroid hormones. Given the marked species differences in adrenal biology, the underlying mechanisms of human adrenal aging have not been sufficiently studied. This study was designed to elucidate the mechanisms linking the functional and structural alterations of the human adrenal cortex.

METHODS

We conducted single-cell RNA sequencing and spatial transcriptomics analysis of the aged human adrenal cortex.

RESULTS

The data of this study suggest that the layer-specific alterations of multiple signaling pathways underlie the abnormal layered structure and layer-specific changes in steroidogenic cells. We also highlighted that macrophages mediate age-related adrenocortical cell inflammation and senescence.

CONCLUSIONS

This study is the first detailed analysis of the aged human adrenal cortex at single-cell resolution and helps to elucidate the mechanism of human adrenal aging, thereby leading to a better understanding of the pathophysiology of age-related disorders associated with adrenal aging.

Patient-derived follicular lymphoma spheroids recapitulate lymph node signaling and immune profile uncovering galectin-9 as a novel immunotherapeutic target

Follicular lymphoma (FL), the most common indolent non-Hodgkin lymphoma, constitutes a paradigm of immune tumor microenvironment (TME) contribution to disease onset, progression, and heterogenous clinical outcome. Here we present the first FL-Patient Derived Lymphoma Spheroid (FL-PDLS), including fundamental immune actors and features of TME in FL lymph nodes (LNs). FL-PDLS is organized in disc-shaped 3D structures composed of proliferating B and T cells, together with macrophages with an intermediate M1/M2 phenotype. FL-PDLS recapitulates the most relevant B-cell transcriptional pathways present in FL-LN (proliferation, epigenetic regulation, mTOR, adaptive immune system, among others). The T cell compartment in the FL-PDLS preserves CD4 subsets (follicular helper, regulatory, and follicular regulatory), also encompassing the spectrum of activation/exhaustion phenotypes in CD4 and CD8 populations. Moreover, this system is suitable for chemo and immunotherapy testing, recapitulating results obtained in the clinic. FL-PDLS allowed uncovering that soluble galectin-9 limits rituximab, rituximab, plus nivolumab/TIM-3 antitumoral activities. Blocking galectin-9 improves rituximab efficacy, highlighting galectin-9 as a novel immunotherapeutic target in FL. In conclusion, FL-PDLS maintains the crosstalk between malignant B cells and the immune LN-TME and constitutes a robust and multiplexed pre-clinical tool to perform drug screening in a patient-derived system, advancing toward personalized therapeutic approaches.

Targeting PHGDH reverses the immunosuppressive phenotype of tumor-associated macrophages through α-ketoglutarate and mTORC1 signaling

Phosphoglycerate dehydrogenase (PHGDH) has emerged as a crucial factor in macromolecule synthesis, neutralizing oxidative stress, and regulating methylation reactions in cancer cells, lymphocytes, and endothelial cells. However, the role of PHGDH in tumor-associated macrophages (TAMs) is poorly understood. Here, we found that the T helper 2 (Th2) cytokine interleukin-4 and tumor-conditioned media upregulate the expression of PHGDH in macrophages and promote immunosuppressive M2 macrophage activation and proliferation. Loss of PHGDH disrupts cellular metabolism and mitochondrial respiration, which are essential for immunosuppressive macrophages. Mechanistically, PHGDH-mediated serine biosynthesis promotes α-ketoglutarate production, which activates mTORC1 signaling and contributes to the maintenance of an M2-like macrophage phenotype in the tumor microenvironment. Genetic ablation of PHGDH in macrophages from tumor-bearing mice results in attenuated tumor growth, reduced TAM infiltration, a phenotypic shift of M2-like TAMs toward an M1-like phenotype, downregulated PD-L1 expression and enhanced antitumor T-cell immunity. Our study provides a strong basis for further exploration of PHGDH as a potential target to counteract TAM-mediated immunosuppression and hinder tumor progression.

Multi-omics analysis-based macrophage differentiation-associated papillary thyroid cancer patient classifier

BACKGROUND

The reclassification of Papillary Thyroid Carcinoma (PTC) is an area of research that warrants attention. The connection between thyroid cancer, inflammation, and immune responses necessitates considering the mechanisms of differential prognosis of thyroid tumors from an immunological perspective. Given the high adaptability of macrophages to environmental stimuli, focusing on the differentiation characteristics of macrophages might offer a novel approach to address the issues related to PTC subtyping.

METHODS

Single-cell RNA sequencing data of medullary cells infiltrated by papillary thyroid carcinoma obtained from public databases was subjected to dimensionality reduction clustering analysis. The RunUMAP and FindAllMarkers functions were utilized to identify the gene expression matrix of different clusters. Cell differentiation trajectory analysis was conducted using the Monocle R package. A complex regulatory network for the classification of Immune status and Macrophage differentiation-associated Papillary Thyroid Cancer Classification (IMPTCC) was constructed through quantitative multi-omics analysis. Immunohistochemistry (IHC) staining was utilized for pathological histology validation.

RESULTS

Through the integration of single-cell RNA and bulk sequencing data combined with multi-omics analysis, we identified crucial transcription factors, immune cells/immune functions, and signaling pathways. Based on this, regulatory networks for three IMPTCC clusters were established.

CONCLUSION

Based on the co-expression network analysis results, we identified three subtypes of IMPTCC: Immune-Suppressive Macrophage differentiation-associated Papillary Thyroid Carcinoma Classification (ISMPTCC), Immune-Neutral Macrophage differentiation-associated Papillary Thyroid Carcinoma Classification (INMPTCC), and Immune-Activated Macrophage differentiation-associated Papillary Thyroid Carcinoma Classification (IAMPTCC). Each subtype exhibits distinct metabolic, immune, and regulatory characteristics corresponding to different states of macrophage differentiation.

Microglia and macrophage metabolism: a regulator of cerebral gliomas

Reciprocal interactions between the tumor microenvironment (TME) and cancer cells play important roles in tumorigenesis and progression of glioma. Glioma-associated macrophages (GAMs), either of peripheral origin or representing brain-intrinsic microglia, are the majority population of infiltrating immune cells in glioma. GAMs, usually classified into M1 and M2 phenotypes, have remarkable plasticity and regulate tumor progression through different metabolic pathways. Recently, research efforts have increasingly focused on GAMs metabolism as potential targets for glioma therapy. This review aims to delineate the metabolic characteristics of GAMs within the TME and provide a summary of current therapeutic strategies targeting GAMs metabolism in glioma. The goal is to provide novel insights and therapeutic pathways for glioma by highlighting the significance of GAMs metabolism.

A Lacticaseibacillus rhamnosus secretome induces immunoregulatory transcriptional, functional and immunometabolic signatures in human THP-1 monocytes

Macrophage responses to activation are fluid and dynamic in their ability to respond appropriately to challenges, a role integral to host defence. While bacteria can influence macrophage differentiation and polarization into pro-inflammatory and alternatively activated phenotypes through direct interactions, many questions surround indirect communication mechanisms mediated through secretomes derived from gut bacteria, such as lactobacilli. We examined effects of secretome-mediated conditioning on THP-1 human monocytes, focusing on the ability of the Lacticaseibacillus rhamnosus R0011 secretome (LrS) to drive macrophage differentiation and polarization and prime immune responses to subsequent challenge with lipopolysaccharide (LPS). Genome-wide transcriptional profiling revealed increased M2-associated gene transcription in response to LrS conditioning in THP-1 cells. Cytokine and chemokine profiling confirmed these results, indicating increased M2-associated chemokine and cytokine production (IL-1Ra, IL-10). These cells had increased cell-surface marker expression of CD11b, CD86, and CX3CR1, coupled with reduced expression of the M1 macrophage-associated marker CD64. Mitochondrial substrate utilization assays indicated diminished reliance on glycolytic substrates, coupled with increased utilization of citric acid cycle intermediates, characteristics of functional M2 activity. LPS challenge of LrS-conditioned THP-1s revealed heightened responsiveness, indicative of innate immune priming. Resting stage THP-1 macrophages co-conditioned with LrS and retinoic acid also displayed an immunoregulatory phenotype with expression of CD83, CD11c and CD103 and production of regulatory cytokines. Secretome-mediated conditioning of macrophages into an immunoregulatory phenotype is an uncharacterized and potentially important route through which lactic acid bacteria and the gut microbiota may train and shape innate immunity at the gut-mucosal interface.

Phenotypic comparison and the potential antitumor function of immortalized bone marrow-derived macrophages (iBMDMs)

Introduction

Macrophages are an important component of innate immunity and involved in the immune regulation of multiple diseases. The functional diversity and plasticity make macrophages to exhibit different polarization phenotypes after different stimuli. During tumor progression, the M2-like polarized tumor-associated macrophages (TAMs) promote tumor progression by assisting immune escape, facilitating tumor cell metastasis, and switching tumor angiogenesis. Our previous studies demonstrated that functional remodeling of TAMs through engineered-modifying or gene-editing provides the potential immunotherapy for tumor. However, lack of proliferation capacity and maintained immune memory of infused macrophages restricts the application of macrophage-based therapeutic strategies in the repressive tumor immune microenvironment (TIME). Although J2 retrovirus infection enabled immortalization of bone marrow-derived macrophages (iBMDMs) and facilitated the mechanisms exploration and application, little is known about the phenotypic and functional differences among multi kinds of macrophages.

Methods

HE staining was used to detect the biosafety of iBMDMs, and real-time quantitative PCR, immunofluorescence staining, and ELISA were used to detect the polarization response and expression of chemokines in iBMDMs. Flow cytometry, scratch assay, real-time quantitative PCR, and crystal violet staining were used to analyze its phagocytic function, as well as its impact on tumor cell migration, proliferation, and apoptosis. Not only that, the inhibitory effect of iBMDMs on tumor growth was detected through subcutaneous tumor loading, while the tumor tissue was paraffin sectioned and flow cytometry was used to detect its impact on the tumor microenvironment.

Results

In this study, we demonstrated iBMDMs exhibited the features of rapid proliferation and long-term survival. We also compared iBMDMs with RAW264.7 cell line and mouse primary BMDMs with in vitro and in vivo experiments, indicating that the iBMDMs could undergo the same polarization response as normal macrophages with no obvious cellular morphology changes after polarization. What's more, iBMDMs owned stronger phagocytosis and pro-apoptosis functions on tumor cells. In addition, M1-polarized iBMDMs could maintain the anti-tumor phenotypes and domesticated the recruited macrophages of receptor mice, which further improved the TIME and repressed tumor growth.

Discussion

iBMDMs can serve as a good object for the function and mechanism study of macrophages and the optional source of macrophage immunotherapy.

Tumor and Peritoneum-Associated Macrophage Gene Signature as a Novel Molecular Biomarker in Gastric Cancer

A spectrum of immune states resulting from tumor resident macrophages and T-lymphocytes in the solid tumor microenvironment correlates with patient outcomes. We hypothesized that in gastric cancer (GC), macrophages in a polarized immunosuppressive transcriptional state would be prognostic of poor survival. We derived transcriptomic signatures for M2 (M2TS, MRC1; MS4A4A; CD36; CCL13; CCL18; CCL23; SLC38A6; FGL2; FN1; MAF) and M1 (M1TS, CCR7; IL2RA; CXCL11; CCL19; CXCL10; PLA1A; PTX3) macrophages, and cytolytic T-lymphocytes (CTLTS, GZMA; GZMB; GZMH; GZMM; PRF1). Primary GC in a TCGA stomach cancer dataset was evaluated for signature expressions, and a log-rank test determined overall survival (OS) and the disease-free interval (DFI). In 341 TCGA GC entries, high M2TS expression was associated with histological types and later stages. Low M2TS expression was associated with significantly better 5-year OS and DFI. We validated M2TS in prospectively collected peritoneal fluid of a GC patient cohort (n = 28). Single-cell RNA sequencing was used for signature expression in CD68+CD163+ cells and the log-rank test compared OS. GC patients with high M2TS in CD68+CD163+ cells in their peritoneal fluid had significantly worse OS than those with low expression. Multivariate analyses confirmed M2TS was significantly and independently associated with survival. As an independent predictor of poor survival, M2TS may be prognostic in primary tumors and peritoneal fluid of GC patients.

Skeletal muscle of young females under resistance exercise exhibits a unique innate immune cell infiltration profile compared to males and elderly individuals

Muscle damage resulting from physical activities such as exercise triggers an immune response crucial for tissue repair and recovery. This study investigates the immune cell profiles in muscle biopsies of individuals engaged in resistance exercise (RE) and explores the impact of age and sex on the immune response following exercise-induced muscle damage. Microarray datasets from muscle biopsies of young and old subjects were analyzed, focusing on the gene expression patterns associated with immune cell activation. Genes were compared with immune cell signatures to reveal the cellular landscape during exercise. Results show that the most significant modulated gene after RE was Folliculin Interacting Protein 2 (FNIP2) a crucial regulator in cellular homeostasis. Moreover, the transcriptome was stratified based on the expression of FNIP2 and the 203 genes common to the groups obtained based on sex and age. Gene ontology analysis highlighted the FLCN-FNIP1-FNIP2 complex, which exerts as a negative feedback loop to Pi3k-Akt-mTORC1 pathway. Furthermore, we highlighted that the young females exhibit a distinct innate immune cell activation signature compared to males after a RE session. Specifically, young females demonstrate a notable overlap with dendritic cells (DCs), M1 macrophages, M2 macrophages, and neutrophils, while young males overlap with M1 macrophages, M2 macrophages, and motor neurons. Interestingly, in elderly subjects, both sexes display M1 macrophage activation signatures. Comparison of young and elderly signatures reveals an increased M1 macrophage percentage in young subjects. Additionally, common genes were identified in both sexes across different age groups, elucidating biological functions related to cell remodeling and immune activation. This study underscores the intricate interplay between sex, age, and the immune response in muscle tissue following RE, offering potential directions for future research. Nevertheless, there is a need for further studies to delve deeper and confirm the dynamics of immune cells in response to exercise-induced muscle damage.

Effect of acute inflammatory reaction induced by biopsy on tumor microenvironment

When it comes to the diagnosis of solid tumors, biopsy is always the gold standard. However, traumatic and inflammatory stimuli are so closely related to tumor initiation and development that the acute inflammatory response induced by biopsy can give rise to changes in the tumor microenvironment, including recruitment of immunosuppressive cells (M2 macrophages, Treg cells, Tumor-associated neutrophils) and secretion of inflammation-associated cytokines, to create immunosuppressive conditions that enable the increase of circulating tumor cells in the peripheral circulation and promote the metastatic spread of tumors after surgery. In this review, we discuss dynamic changes and inhibitory characteristics of biopsy on tumor microenvironment. By investigating its mechanism of action and summarizing the current therapeutic strategies for biopsy-induced tumor immunosuppressive microenvironment, the future of using biopsy-induced inflammation to improve the therapeutic effects and prognosis of patients is prospected.

High-Dimensional Single-Cell Multimodal Landscape of Human Carotid Atherosclerosis

BACKGROUND

Atherosclerotic plaques are complex tissues composed of a heterogeneous mixture of cells. However, our understanding of the comprehensive transcriptional and phenotypic landscape of the cells within these lesions is limited.

METHODS

To characterize the landscape of human carotid atherosclerosis in greater detail, we combined cellular indexing of transcriptomes and epitopes by sequencing and single-cell RNA sequencing to classify all cell types within lesions (n=21; 13 symptomatic) to achieve a comprehensive multimodal understanding of the cellular identities of atherosclerosis and their association with clinical pathophysiology.

RESULTS

We identified 25 cell populations, each with a unique multiomic signature, including macrophages, T cells, NK (natural killer) cells, mast cells, B cells, plasma cells, neutrophils, dendritic cells, endothelial cells, fibroblasts, and smooth muscle cells (SMCs). Among the macrophages, we identified 2 proinflammatory subsets enriched in IL-1B (interleukin-1B) or C1Q expression, 2 TREM2-positive foam cells (1 expressing inflammatory genes), and subpopulations with a proliferative gene signature and SMC-specific gene signature with fibrotic pathways upregulated. Further characterization revealed various subsets of SMCs and fibroblasts, including SMC-derived foam cells. These foamy SMCs were localized in the deep intima of coronary atherosclerotic lesions. Utilizing cellular indexing of transcriptomes and epitopes by sequencing data, we developed a flow cytometry panel, using cell surface proteins CD29, CD142, and CD90, to isolate SMC-derived cells from lesions. Lastly, we observed reduced proportions of efferocytotic macrophages, classically activated endothelial cells, and contractile and modulated SMC-derived cells, while inflammatory SMCs were enriched in plaques of clinically symptomatic versus asymptomatic patients.

CONCLUSIONS

Our multimodal atlas of cell populations within atherosclerosis provides novel insights into the diversity, phenotype, location, isolation, and clinical relevance of the unique cellular composition of human carotid atherosclerosis. These findings facilitate both the mapping of cardiovascular disease susceptibility loci to specific cell types and the identification of novel molecular and cellular therapeutic targets for the treatment of the disease.

Advances in Engineered Macrophages: A New Frontier in Cancer Immunotherapy

Macrophages, as pivotal cells within the tumour microenvironment, significantly influence the impact of and reactions to treatments for solid tumours. The rapid evolution of bioengineering technology has revealed the vast potential of engineered macrophages in immunotherapy, disease diagnosis, and tissue engineering. Given this landscape, the goal of harnessing and innovating macrophages as a novel strategy for solid tumour immunotherapy cannot be overstated. The diverse strategies for engineered macrophages in the realm of cancer immunotherapy, encompassing macrophage drug delivery systems, chimeric antigen receptor macrophage therapy, and synergistic treatment approaches involving bacterial outer membrane vesicles and macrophages, are meticulously examined in this review. These methodologies are designed to enhance the therapeutic efficacy of macrophages against solid tumours, particularly those that are drug-resistant and metastatic. Collectively, these immunotherapies are poised to supplement and refine current solid tumour treatment paradigms, thus heralding a new frontier in the fight against malignant tumours.

Acid-base transporters in the context of tumor heterogeneity

The copious metabolic acid production and -extrusion by cancer cells render poorly vascularized regions of solid tumors highly acidic. A growing list of proton - and bicarbonate transporters has been suggested to contribute to net acid extrusion from cancer cells, and/or been shown to be dysregulated and favor malignant development in various cancers. The great majority of these roles have been studied at the level of the cancer cells. However, recent advances in understanding of the cellular and physicochemical heterogeneity of solid tumors both enable and necessitate a reexamination of the regulation and roles of acid-base transporters in such malignancies. This review will briefly summarize the state-of-the-art, with a focus on the SLC9A and SLC4A families, for which most evidence is available. This is followed by a discussion of key concepts and open questions arising from recent insights and of the challenges that need to be tackled to address them. Finally, opportunities and challenges in therapeutic targeting of the acid-base transportome in cancers will be addressed.

Nanoparticle-encapsulated retinoic acid for the modulation of bone marrow hematopoietic stem cell niche

More effective approaches are needed in the treatment of blood cancers, in particular acute myeloid leukemia (AML), that are able to eliminate resistant leukemia stem cells (LSCs) at the bone marrow (BM), after a chemotherapy session, and then enhance hematopoietic stem cell (HSC) engraftment for the re-establishment of the HSC compartment. Here, we investigate whether light-activatable nanoparticles (NPs) encapsulating all-trans-retinoic acid (RA+NPs) could solve both problems. Our in vitro results show that mouse AML cells transfected with RA+NPs differentiate towards antitumoral M1 macrophages through RIG.1 and OASL gene expression. Our in vivo results further show that mouse AML cells transfected with RA+NPs home at the BM after transplantation in an AML mouse model. The photo-disassembly of the NPs within the grafted cells by a blue laser enables their differentiation towards a macrophage lineage. This macrophage activation seems to have systemic anti-leukemic effect within the BM, with a significant reduction of leukemic cells in all BM compartments, of animals treated with RA+NPs, when compared with animals treated with empty NPs. In a separate group of experiments, we show for the first time that normal HSCs transfected with RA+NPs show superior engraftment at the BM niche than cells without treatment or treated with empty NPs. This is the first time that the activity of RA is tested in terms of long-term hematopoietic reconstitution after transplant using an in situ activation approach without any exogenous priming or genetic conditioning of the transplanted cells. Overall, the approach documented here has the potential to improve consolidation therapy in AML since it allows a dual intervention in the BM niche: to tackle resistant leukemia and improve HSC engraftment at the same time.

A deep profile of gene expression across 18 human cancers

Clinically and biologically valuable information may reside untapped in large cancer gene expression data sets. Deep unsupervised learning has the potential to extract this information with unprecedented efficacy but has thus far been hampered by a lack of biological interpretability and robustness. Here, we present DeepProfile, a comprehensive framework that addresses current challenges in applying unsupervised deep learning to gene expression profiles. We use DeepProfile to learn low-dimensional latent spaces for 18 human cancers from 50,211 transcriptomes. DeepProfile outperforms existing dimensionality reduction methods with respect to biological interpretability. Using DeepProfile interpretability methods, we show that genes that are universally important in defining the latent spaces across all cancer types control immune cell activation, while cancer type-specific genes and pathways define molecular disease subtypes. By linking DeepProfile latent variables to secondary tumor characteristics, we discover that tumor mutation burden is closely associated with the expression of cell cycle-related genes. DNA mismatch repair and MHC class II antigen presentation pathway expression, on the other hand, are consistently associated with patient survival. We validate these results through Kaplan-Meier analyses and nominate tumor-associated macrophages as an important source of survival-correlated MHC class II transcripts. Our results illustrate the power of unsupervised deep learning for discovery of novel cancer biology from existing gene expression data.

Single cell atlas of human gastric muscle immune cells and macrophage-driven changes in idiopathic gastroparesis

Gastrointestinal immune cells, particularly muscularis macrophages (MM) interact with the enteric nervous system and influence gastrointestinal motility. Here we determine the human gastric muscle immunome and its changes in patients with idiopathic gastroparesis (IG). Single cell sequencing was performed on 26,000 CD45+ cells obtained from the gastric tissue of 20 subjects. We demonstrate 11 immune cell clusters with T cells being most abundant followed by myeloid cells. The proportions of cells belonging to the 11 clusters were similar between IG and controls. However, 9/11 clusters showed 578-11,429 differentially expressed genes. In IG, MM had decreased expression of tissue-protective and microglial genes and increased the expression of monocyte trafficking and stromal activating genes. Furthermore, in IG, IL12 mediated JAK-STAT signaling involved in the activation of tissue-resident macrophages and Eph-ephrin signaling involved in monocyte chemotaxis were upregulated. Patients with IG had a greater abundance of monocyte-like cells. These data further link immune dysregulation to the pathophysiology of gastroparesis.

CD4+ T cell activation distinguishes response to anti-PD-L1+anti-CTLA4 therapy from anti-PD-L1 monotherapy

Cancer patients often receive a combination of antibodies targeting programmed death-ligand 1 (PD-L1) and cytotoxic T lymphocyte antigen-4 (CTLA4). We conducted a window-of-opportunity study in head and neck squamous cell carcinoma (HNSCC) to examine the contribution of anti-CTLA4 to anti-PD-L1 therapy. Single-cell profiling of on- versus pre-treatment biopsies identified T cell expansion as an early response marker. In tumors, anti-PD-L1 triggered the expansion of mostly CD8+ T cells, whereas combination therapy expanded both CD4+ and CD8+ T cells. Such CD4+ T cells exhibited an activated T helper 1 (Th1) phenotype. CD4+ and CD8+ T cells co-localized with and were surrounded by dendritic cells expressing T cell homing factors or antibody-producing plasma cells. T cell receptor tracing suggests that anti-CTLA4, but not anti-PD-L1, triggers the trafficking of CD4+ naive/central-memory T cells from tumor-draining lymph nodes (tdLNs), via blood, to the tumor wherein T cells acquire a Th1 phenotype. Thus, CD4+ T cell activation and recruitment from tdLNs are hallmarks of early response to anti-PD-L1 plus anti-CTLA4 in HNSCC.

NLRP3 Inhibition Leads to Impaired Mucosal Fibroblast Function in Patients with Inflammatory Bowel Diseases

BACKGROUND AND AIMS

Inflammatory bowel diseases (IBD) are characterized by mucosal inflammation and sequential fibrosis formation, but the exact role of the hyperactive NLRP3 inflammasome in these processes is unclear. Thus, we studied the expression and function of the NLRP3 inflammasome in the context of inflammation and fibrosis in IBD.

METHODS

We analysed intestinal NLRP3 expression in mucosal immune cells and fibroblasts from IBD patients and NLRP3-associated gene expression via single-cell RNA sequencing and microarray analyses. Furthermore, cytokine secretion of NLRP3 inhibitor treated blood and mucosal cells, as well as proliferation, collagen production, and cell death of NLRP3 inhibitor treated intestinal fibroblasts from IBD patients were studied.

RESULTS

We found increased NLRP3 expression in the inflamed mucosa of IBD patients and NLRP3 inhibition led to reduced IL-1β and IL-18 production in blood cells and diminished the bioactive form of mucosal IL-1β. Single cell analysis identified overlapping expression patterns of NLRP3 and IL-1β in classically activated intestinal macrophages and we also detected NLRP3 expression in CD163+ macrophages. In addition, NLRP3 expression was also found in intestinal fibroblasts from IBD patients. Inhibition of NLRP3 led to reduced proliferation of intestinal fibroblasts, which was associated with a marked decrease in production of collagen type I and type VI in IBD patients. Moreover, NLRP3 inhibition in intestinal fibroblasts induced autophagy, a cellular process involved in collagen degradation.

CONCLUSIONS

In the presented study, we demonstrate that inhibiting NLRP3 might pave the way for novel therapeutic approaches in IBD, especially to prevent the severe complication of intestinal fibrosis formation.

Dissecting the immune discrepancies in mouse liver allograft tolerance and heart/kidney allograft rejection

The liver is the most tolerogenic of transplanted organs. However, the mechanisms underlying liver transplant tolerance are not well understood. The comparison between liver transplantation tolerance and heart/kidney transplantation rejection will deepen our understanding of tolerance and rejection in solid organs. Here, we built a mouse model of liver, heart and kidney allograft and performed single-cell RNA sequencing of 66,393 cells to describe the cell composition and immune cell interactions at the early stage of tolerance or rejection. We also performed bulk RNA-seq of mouse liver allografts from Day 7 to Day 60 post-transplantation to map the dynamic transcriptional variation in spontaneous tolerance. The transcriptome of lymphocytes and myeloid cells were characterized and compared in three types of organ allografts. Cell-cell interaction networks reveal the coordinated function of Kupffer cells, macrophages and their associated metabolic processes, including insulin receptor signalling and oxidative phosphorylation in tolerance induction. Cd11b+ dendritic cells (DCs) in liver allografts were found to inhibit cytotoxic T cells by secreting anti-inflammatory cytokines such as Il10. In summary, we profiled single-cell transcriptome analysis of mouse solid organ allografts. We characterized the immune microenvironment of mouse organ allografts in the acute rejection state (heart, kidney) and tolerance state (liver).

Peri-operative individually tailored psychological intervention in breast cancer patients improves psychological indices and molecular biomarkers of metastasis in excised tumors

Perioperative stress and inflammatory signaling can invigorate pro-metastatic molecular processes in patients' tumors, potentially worsening long-term survival. Yet, it is unknown whether pre-operative psychotherapeutic interventions can attenuate such effects. Herein, three weeks before surgery, forty women diagnosed with stage I-III invasive ductal/lobular breast carcinoma were randomized to a 6-week one-on-one psychological intervention (6 meetings with a medical psychologist and bi-weekly phone calls) versus standard nursing-staff-attention. The intervention protocol was individually tailored based on evaluation of patients' emotional, cognitive, physiological, and behavioral stress response-patterns, and also included psychoeducation regarding medical treatments and recruitment of social support. Resected primary tumors were subjected to whole-genome RNA sequencing and bioinformatic analyses, assessing a priori hypothesized cancer-relevant molecular signatures. Self-report questionnaires (BSI-18, Hope-18, MSPSS, and a stress-scale) were collected three (T1) and one (T2) week before surgery, a day before (T3) and after (T4) surgery, and three weeks (T5) and 3-months (T6) following surgery. The intervention reduced distress (GSI), depression, and somatization scores (BSI-18: p < 0.01, p < 0.05, p < 0.05; T5 vs. T1). Additionally, tumors from treated patients (vs. controls) showed: (i) decreased activity of transcription control pathways involved in adrenergic and glucocorticoid signaling (CREB, GR) (p < 0.001), pro-inflammatory signaling (NFkB) (p < 0.01), and pro-malignant signaling (ETS1, STAT and GATA families) (p < 0.001, p < 0.01, p < 0.005); (ii) increased M1 macrophage polarization (p < 0.05), and CD4+ T cell activity (p < 0.01); and an unexpected increase in epithelial-to-mesenchymal-transition (EMT) signature (p < 0.005). This is the first randomized controlled trial to show beneficial effects of a psychological perioperative intervention on tumor pro-metastatic molecular biomarkers.

Tissue-resident macrophages specifically express Lactotransferrin and Vegfc during ear pinna regeneration in spiny mice

The details of how macrophages control different healing trajectories (regeneration vs. scar formation) remain poorly defined. Spiny mice (Acomys spp.) can regenerate external ear pinnae tissue, whereas lab mice (Mus musculus) form scar tissue in response to an identical injury. Here, we used this dual species system to dissect macrophage phenotypes between healing modes. We identified secreted factors from activated Acomys macrophages that induce a pro-regenerative phenotype in fibroblasts from both species. Transcriptional profiling of Acomys macrophages and subsequent in vitro tests identified VEGFC, PDGFA, and Lactotransferrin (LTF) as potential pro-regenerative modulators. Examining macrophages in vivo, we found that Acomys-resident macrophages secreted VEGFC and LTF, whereas Mus macrophages do not. Lastly, we demonstrate the requirement for VEGFC during regeneration and find that interrupting lymphangiogenesis delays blastema and new tissue formation. Together, our results demonstrate that cell-autonomous mechanisms govern how macrophages react to the same stimuli to differentially produce factors that facilitate regeneration.

PD-L1-expressing tumor-associated macrophages are immunostimulatory and associate with good clinical outcome in human breast cancer

Tumor-associated macrophages (TAMs) are the predominant cells that express programmed cell death ligand 1 (PD-L1) within human tumors in addition to cancer cells, and PD-L1+ TAMs are generally thought to be immunosuppressive within the tumor immune microenvironment (TIME). Using single-cell transcriptomic and spatial multiplex immunofluorescence analyses, we show that PD-L1+ TAMs are mature and immunostimulatory with spatial preference to T cells. In contrast, PD-L1- TAMs are immunosuppressive and spatially co-localize with cancer cells. Either higher density of PD-L1+ TAMs alone or ratio of PD-L1+/PD-L1- TAMs correlate with favorable clinical outcome in two independent cohorts of patients with breast cancer. Mechanistically, we show that PD-L1 is upregulated during the monocyte-to-macrophage maturation and differentiation process and does not require external IFN-γ stimulus. Functionally, PD-L1+ TAMs are more mature/activated and promote CD8+ T cells proliferation and cytotoxic capacity. Together, our findings reveal insights into the immunological significance of PD-L1 within the TIME.

Protein kinase D drives the secretion of invasion mediators in triple-negative breast cancer cell lines

The protein kinase D (PKD) family members regulate the fission of cargo vesicles at the Golgi complex and play a pro-oncogenic role in triple-negative breast cancer (TNBC). Whether PKD facilitates the secretion of tumor-promoting factors in TNBC, however, is still unknown. Using the pharmacological inhibition of PKD activity and siRNA-mediated depletion of PKD2 and PKD3, we identified the PKD-dependent secretome of the TNBC cell lines MDA-MB-231 and MDA-MB-468. Mass spectrometry-based proteomics and antibody-based assays revealed a significant downregulation of extracellular matrix related proteins and pro-invasive factors such as LIF, MMP-1, MMP-13, IL-11, M-CSF and GM-CSF in PKD-perturbed cells. Notably, secretion of these proteins in MDA-MB-231 cells was predominantly controlled by PKD2 and enhanced spheroid invasion. Consistently, PKD-dependent secretion of pro-invasive factors was more pronounced in metastatic TNBC cell lines. Our study thus uncovers a novel role of PKD2 in releasing a pro-invasive secretome.

Spatial transcriptomics reveals alterations in perivascular macrophage lipid metabolism in the onset of Wooden Breast myopathy in broiler chickens

This study aims to use spatial transcriptomics to characterize the cell-type-specific expression profile associated with the microscopic features observed in Wooden Breast myopathy. 1 cm3 muscle sample was dissected from the cranial part of the right pectoralis major muscle from three randomly sampled broiler chickens at 23 days post-hatch and processed with Visium Spatial Gene Expression kits (10X Genomics), followed by high-resolution imaging and sequencing on the Illumina Nextseq 2000 system. WB classification was based on histopathologic features identified. Sequence reads were aligned to the chicken reference genome (Galgal6) and mapped to histological images. Unsupervised K-means clustering and Seurat integrative analysis differentiated histologic features and their specific gene expression pattern, including lipid laden macrophages (LLM), unaffected myofibers, myositis and vasculature. In particular, LLM exhibited reprogramming of lipid metabolism with up-regulated lipid transporters and genes in peroxisome proliferator-activated receptors pathway, possibly through P. Moreover, overexpression of fatty acid binding protein 5 could enhance fatty acid uptake in adjacent veins. In myositis regions, increased expression of cathepsins may play a role in muscle homeostasis and repair by mediating lysosomal activity and apoptosis. A better knowledge of different cell-type interactions at early stages of WB is essential in developing a comprehensive understanding.

Blockade of C5a receptor unleashes tumor-associated macrophage antitumor response and enhances CXCL9-dependent CD8+ T cell activity

Macrophages play a crucial role in shaping the immune state within the tumor microenvironment (TME) and are often influenced by tumors to hinder antitumor immunity. However, the underlying mechanisms are still elusive. Here, we observed abnormal expression of complement 5a receptor (C5aR) in human ovarian cancer (OC), and identified high levels of C5aR expression on tumor-associated macrophages (TAMs), which led to the polarization of TAMs toward an immunosuppressive phenotype. C5aR knockout or inhibitor treatment restored TAM antitumor response and attenuated tumor progression. Mechanistically, C5aR deficiency reprogrammed macrophages from a protumor state to an antitumor state, associating with the upregulation of immune response and stimulation pathways, which in turn resulted in the enhanced antitumor response of cytotoxic T cells in a manner dependent on chemokine (C-X-C motif) ligand 9 (CXCL9). The pharmacological inhibition of C5aR also improved the efficacy of immune checkpoint blockade therapy. In patients, C5aR expression associated with CXCL9 production and infiltration of CD8+ T cells, and a high C5aR level predicted poor clinical outcomes and worse benefits from anti-PD-1 therapy. Thus, our study sheds light on the mechanisms underlying the modulation of TAM antitumor immune response by the C5a-C5aR axis and highlights the potential of targeting C5aR for clinical applications.

The Bisdioxopiperazine ICRF-193 Attenuates LPS-induced IL-1β Secretion by Macrophages

Inhibiting pathological secretion of Interleukin-1β has shown beneficial effects in disease models and in the clinic and thus there is interest in finding inhibitors that can reduce its release from macrophages in response to their activation by foreign pathogens. We used an in vitro human macrophage model to investigate whether ICRF-193, a Topoisomerase II inhibitor could modulate IL1B mRNA expression and IL-1β secretion. These macrophage-like cells readily secrete IL-1β in response to Lipopolysaccharide (LPS). Upon exposure to a non-toxic dose of ICRF-193, IL-1β secretion was diminished by ~ 40%; however, level of transcription of IL1B was unaffected. We show that there was no Topoisomerase 2B (TOP2B) binding to several IL1B gene sites, which may explain why ICRF-193 does not alter IL1B mRNA levels. Hence, we show for the first time that ICRF-193 can reduce IL-1β secretion. Its low cost and the development of water-soluble prodrugs of ICRF-193 warrants its further investigation in the modulation of pathological secretion of this cytokine for the treatment of inflammatory disorders. (165 words).

Antigen presenting cells in cancer immunity and mediation of immune checkpoint blockade

Antigen-presenting cells (APCs) are pivotal mediators of immune responses. Their role has increasingly been spotlighted in the realm of cancer immunology, particularly as our understanding of immunotherapy continues to evolve and improve. There is growing evidence that these cells play a non-trivial role in cancer immunity and have roles dependent on surface markers, growth factors, transcription factors, and their surrounding environment. The main dendritic cell (DC) subsets found in cancer are conventional DCs (cDC1 and cDC2), monocyte-derived DCs (moDC), plasmacytoid DCs (pDC), and mature and regulatory DCs (mregDC). The notable subsets of monocytes and macrophages include classical and non-classical monocytes, macrophages, which demonstrate a continuum from a pro-inflammatory (M1) phenotype to an anti-inflammatory (M2) phenotype, and tumor-associated macrophages (TAMs). Despite their classification in the same cell type, each subset may take on an immune-activating or immunosuppressive phenotype, shaped by factors in the tumor microenvironment (TME). In this review, we introduce the role of DCs, monocytes, and macrophages and recent studies investigating them in the cancer immunity context. Additionally, we review how certain characteristics such as abundance, surface markers, and indirect or direct signaling pathways of DCs and macrophages may influence tumor response to immune checkpoint blockade (ICB) therapy. We also highlight existing knowledge gaps regarding the precise contributions of different myeloid cell subsets in influencing the response to ICB therapy. These findings provide a summary of our current understanding of myeloid cells in mediating cancer immunity and ICB and offer insight into alternative or combination therapies that may enhance the success of ICB in cancers.

Single-cell RNA sequencing combined with proteomics of infected macrophages reveals prothymosin-α as a target for treatment of apical periodontitis

INTRODUCTION

Chronic apical periodontitis (CAP) is a common infectious disease of the oral cavity. Immune responses and osteoclastogenesis of monocytes/macrophages play a crucial role in CAP progression, and this study want to clarify role of monocytes/macrophages in CAP, which will contribute to treatment of CAP.

OBJECTIVES

We aim to explore the heterogeneity of monocyte populations in periapical lesion of CAP tissues and healthy control (HC) periodontal tissues by single-cell RNA sequencing (scRNA-seq), search novel targets for alleviating CAP, and further validate it by proteomics and in vitro and in vivo evaluations.

METHODS

ScRNA-seq was used to analyze the heterogeneity of monocyte populations in CAP, and proteomics of THP-1-derived macrophages with porphyromonas gingivalis infection were intersected with the differentially expressed genes (DEGs) of macrophages between CAP and HC tissues. The upregulated PTMA (prothymosin-α) were validated by immunofluorescence staining and quantitative real time polymerase chain reaction. We evaluated the effect of thymosin α1 (an amino-terminal proteolytic cleavage product of PTMA protein) on inflammatory factors and osteoclast differentiation of macrophages infected by P. gingivalis. Furthermore, we constructed mouse and rat mandibular bone lesions caused by apical periodontitis, and estimated treatment of systemic and topical administration of PTMA for CAP. Statistical analyses were performed using GraphPad Prism software (v9.2) RESULTS: Monocytes were divided into seven sub-clusters comprising monocyte-macrophage-osteoclast (MMO) differentiation in CAP. 14 up-regulated and 21 down-regulated genes and proteins were intersected between the DEGs of scRNA-seq data and proteomics, including the high expression of PTMA. Thymosin α1 may decrease several inflammatory cytokine expressions and osteoclastogenesis of THP-1-derived macrophages. Both systemic administration in mice and topical administration in the pulp chamber of rats alleviated periapical lesions.

CONCLUSIONS

PTMA upregulation in CAP moderates the inflammatory response and prevents the osteoclastogenesis of macrophages, which provides a basis for targeted therapeutic strategies for CAP.