Asthma is a chronic inflammatory disease of the airway involving various cellular players. Among the different phenotypes of asthma, neutrophilic asthma is often associated with severe airway inflammation and a notable resistance to corticosteroid treatment. Macrophages, as innate immune cells, play a crucial role in the pathogenesis of neutrophilic asthma. They regulate neutrophil recruitment and activation to promote the progression of airway inflammation. During this process, macrophages also undergo changes in aspects such as efferocytosis. We reviewed the recent research progresses regarding the role of macrophages in the pathogenesis of neutrophilic asthma, aiming to provide valuable insights for future studies in this area.
Humans ; Asthma/pathology* ; Neutrophils/pathology* ; Macrophages/immunology* ; Animals ; Phagocytosis

Myeloid-derived cells (MDCs) are crucial in immune response and tissue homeostasis. They have high functional plasticity and can be polarized according to microenvironment signals. These cells, including macrophages, neutrophils, and dendritic cells (DCs), exhibit different functional polarization states in different pathological environments and are involved in the occurrence and development of diseases such as inflammation and tumors. Studies have shown that metabolic reprogramming plays a key role in the functional polarization of MDCs, affecting the cellular energy supply and regulating immune function. This paper reviews classification, function and polarization mechanism of MDCs and discusses metabolic reprogramming. In addition, the therapeutic strategies targeting MDC are summarized, which is expected to provide new targets for tumor immunotherapy.
Humans ; Tumor Microenvironment/immunology* ; Myeloid Cells/metabolism* ; Neoplasms/pathology* ; Animals ; Immunotherapy/methods* ; Dendritic Cells/immunology* ; Macrophages/immunology*

OBJECTIVES: To elucidate the underlying mechanisms of macrophage-mediated inflammation and tissue injury in diabetic foot ulcer (DFU). METHODS: Skin tissue samples were collected from patients with DFU and with non-DFU. A total of 79 272 high-quality cell transcriptomes were obtained using single-cell RNA sequencing. An unbiased clustering approach was employed to identify cell subpopulations. Seurat functions were used to identify differentially expressed genes between DFU and non-DFU groups, and gene ontology (GO) enrichment analysis was used to reveal gene function. Furthermore, cell-cell communication network construction and ligand-receptor interaction analysis were performed to reveal the mechanisms underlying cellular interactions and signaling regulation in the DFU microenvironment from multiple perspectives. RESULTS: The results revealed a significant expansion of myeloid cells in DFU tissues, alongside a marked reduction in structural cells such as endothelial cells, epithelial cells, and smooth muscle cells. Major cell types underwent functional reprogramming, characterized by immune activation and impaired tissue remodeling. Specifically, macrophages in DFU skin tissues exhibited a shift toward a pro-inflammatory M1 phenotype, with upregulation of genes associated with inflammation and oxidative stress. Cell communication analysis further demonstrated that M1 macrophages served as both primary signal receivers and influencers in the COMPLEMENT pathway mediated communication network, and as key signal senders and mediators in the secreted phosphoprotein 1 (SPP1) pathway mediated communication network, actively shaping the inflammatory microenvironment. Key ligand-receptor interactions driving macrophage signaling were identified, including C3-(ITGAM+ITGB2) and SPP1-CD44. CONCLUSIONS This study establishes a comprehensive single-cell atlas of DFU, revealing the role of macrophage-driven cellular networks in chronic inflammation and impaired healing. These findings may offer potential novel therapeutic targets for DFU treatment.
Humans ; Macrophages/immunology* ; Diabetic Foot/pathology* ; Single-Cell Analysis ; Transcriptome ; Gene Expression Profiling ; Inflammation ; Skin ; Cell Communication ; Signal Transduction ; Cellular Reprogramming

Sepsis is a life-threatening organ dysfunction caused by the body's dysregulated response to infection. Reversible myocardial dysfunction caused by sepsis is known as septic cardiomyopathy. A thorough understanding of the pathogenesis of septic cardiomyopathy is crucial for early intervention to prevent its progression and improve the success rate of sepsis treatment. At present, the research on the pathogenesis of septic cardiomyopathy mainly focuses on two aspects: the systemic neuroimmune mechanism and the local changes of cardiomyocytes. The former mainly includes the autonomic nervous dysfunction mainly caused by sympathetic overactivation and the inflammatory storm induced by immune response disorder. The latter covers the dysregulation of calcium homeostasis, mitochondrial dysfunction and energy metabolism disorder of cardiomyocytes. Immune dysfunction is one of the key factors that cause the poor prognosis of patients with septic cardiomyopathy. Macrophages are sentinel cells of the body's innate immunity. Cardiac macrophages have been confirmed to be one of the most heterogeneous immune cells in the heart. According to their origin and differentiation, they can be divided into bone marrow-derived tissue infiltrating macrophages and cardiac resident macrophages, which have roles of polarization, phagocytosis, regulation of inflammatory response, and participate in innate and adaptive immunity. In the occurrence and development of septic cardiomyopathy, cardiac macrophages recruited from the blood participate in balancing the inflammation and repair of myocardial tissue through the conversion of pro-inflammatory phenotype and anti-inflammatory phenotype. Cardiac resident macrophages mediate immune phagocytosis to maintain the local homeostasis of cardiomyocytes, and the glycometabolic reprogramming of macrophages regulates the release of inflammatory factors, while macrophage metabolic reprogramming regulates the release of inflammatory factors. A deeper understanding of the biological behavior of macrophages, and regulating the polarization, metabolism and phagocytosis of cardiac macrophages, could serve as new target for the prevention and treatment of septic cardiomyopathy. Therefore, this article reviews the key pathogenesis of septic cardiomyopathy and the role of macrophages of different origins and differentiation, revealing the possibility of developing new strategies for the prevention and treatment of septic cardiomyopathy.
Humans ; Cardiomyopathies/pathology* ; Macrophages/immunology* ; Sepsis/complications* ; Myocytes, Cardiac

Cervical cancer (CC) has been a hot topic in the field of gynecological cancer due to its high morbidity and mortality. As one of the major components, tumor-associated macrophages (TAMs) play a crucial role in the tumor microenvironment (TME), differentiating into M1 and M2 phenotypes under the influence of various cytokines, with a predominance of the M2 phenotype among TAMs. Notably, the functions of these two phenotypes are almost opposite. M1 macrophages promote inflammation and inhibit tumor development, while M2 macrophages tend to suppress the immune response and promote tumor growth. Additionally, TAMs can influence tumor invasion, metastasis and immune regulation through interacting with various lymphocytes and cytokines. Numerous studies have demonstrated that TAMs can be used as prognostic markers for CC, and as therapeutic targets in clinical setting. A deeper comprehension of interactions between TAMs and CC, achieved by integrating findings and conclusions from various studies, is conducive to the discovery of new directions for research and new perspectives for clinical treatment.
Humans ; Uterine Cervical Neoplasms/pathology* ; Female ; Tumor-Associated Macrophages/metabolism* ; Tumor Microenvironment/immunology* ; Disease Progression ; Cytokines/immunology* ; Animals ; Macrophages/immunology*

Ferroptosis is a form of regulated cell death, which is dependent on iron metabolism imbalance and characterized by lipid peroxidation. Ferroptosis plays a crucial role in various pathological processes. Studies have shown that the occurrence of ferroptosis is closely associated with the progression of hepatocellular carcinoma (HCC). Ferroptosis is involved in regulating the lipid metabolism, iron homeostasis, mitochondrial metabolism, and redox processes in HCC. Additionally, ferroptosis plays a key role in HCC tumor immunity by modulating the phenotype and function of various immune cells in the tumor microenvironment, affecting tumor immune escape and progression. Ferroptosis-induced lipid peroxidation and oxidative stress can promote the polarization of M1 macrophages and enhance the pro-inflammatory response in tumors, inhibiting immune suppressive cells such as myeloid-derived suppressor cells and regulatory T cells to disrupt their immune suppression function. The regulation of expression of ferroptosis-related molecules such as GPX4 and SLC7A11 not only affects the sensitivity of tumor cells to immunotherapy but also directly influences the activity and survival of effector cells such as T cells and dendritic cells, further enhancing or weakening host antitumor immune response. Targeting ferroptosis has demonstrated significant clinical potential in HCC treatment. Induction of ferroptosis by nanomedicines and molecular targeting strategies can directly kill tumor cells or enhance antitumor immune responses. The integration of multimodal therapies with immunotherapy further expands the application of ferroptosis targeting as a cancer therapy. This article reviews the relationship between ferroptosis and antitumor immune responses and the role of ferroptosis in HCC progression from the perspective of tumor immune microenvironment, to provide insights for the development of antitumor immune therapies targeting ferroptosis.
Ferroptosis ; Humans ; Carcinoma, Hepatocellular/pathology* ; Liver Neoplasms/metabolism* ; Tumor Microenvironment/immunology* ; Lipid Peroxidation ; Immunotherapy ; Oxidative Stress ; Iron/metabolism* ; Lipid Metabolism ; Phospholipid Hydroperoxide Glutathione Peroxidase/metabolism* ; Macrophages/immunology* ; Amino Acid Transport System y+

Direct conversion of cardiac fibroblasts (CFs) to cardiomyocytes (CMs) in vivo to regenerate heart tissue is an attractive approach. After myocardial infarction (MI), heart repair proceeds with an inflammation stage initiated by monocytes infiltration of the infarct zone establishing an immune microenvironment. However, whether and how the MI microenvironment influences the reprogramming of CFs remains unclear. Here, we found that in comparison with cardiac fibroblasts (CFs) cultured in vitro, CFs that transplanted into infarct region of MI mouse models resisted to cardiac reprogramming. RNA-seq analysis revealed upregulation of interferon (IFN) response genes in transplanted CFs, and subsequent inhibition of the IFN receptors increased reprogramming efficiency in vivo. Macrophage-secreted IFN-β was identified as the dominant upstream signaling factor after MI. CFs treated with macrophage-conditioned medium containing IFN-β displayed reduced reprogramming efficiency, while macrophage depletion or blocking the IFN signaling pathway after MI increased reprogramming efficiency in vivo. Co-IP, BiFC and Cut-tag assays showed that phosphorylated STAT1 downstream of IFN signaling in CFs could interact with the reprogramming factor GATA4 and inhibit the GATA4 chromatin occupancy in cardiac genes. Furthermore, upregulation of IFN-IFNAR-p-STAT1 signaling could stimulate CFs secretion of CCL2/7/12 chemokines, subsequently recruiting IFN-β-secreting macrophages. Together, these immune cells further activate STAT1 phosphorylation, enhancing CCL2/7/12 secretion and immune cell recruitment, ultimately forming a self-reinforcing positive feedback loop between CFs and macrophages via IFN-IFNAR-p-STAT1 that inhibits cardiac reprogramming in vivo. Cumulatively, our findings uncover an intercellular self-stimulating inflammatory circuit as a microenvironmental molecular barrier of in situ cardiac reprogramming that needs to be overcome for regenerative medicine applications.
Animals ; Mice ; Macrophages/immunology* ; Fibroblasts/cytology* ; Cellular Reprogramming ; STAT1 Transcription Factor/genetics* ; Signal Transduction ; Interferon-beta/genetics* ; Myocardial Infarction/pathology* ; Myocytes, Cardiac/cytology* ; Mice, Inbred C57BL ; GATA4 Transcription Factor/genetics* ; Male ; Cells, Cultured

Inhibition of macrophage-mediated phagocytosis has emerged as an essential mechanism for tumor immune evasion. One mechanism inhibiting the innate response is the presence of the macrophage inhibitory molecule, signal regulatory protein-α (SIRPα), on tumor-associated macrophages (TAMs) and its cognate ligand cluster of differentiation 47 (CD47) on tumor cells in the tumor microenvironment. On the basis of a recently discovered programmed death protein 1 (PD-1) in TAMs, we discuss the potential inhibitory receptors that possess new functions beyond T cell exhaustion in this review. As more and more immune receptors are found to be expressed on TAMs, the corresponding therapies may also stimulate macrophages for phagocytosis and thereby provide extra anti-tumor benefits in cancer therapy. Therefore, identification of biomarkers and combinatorial therapeutic strategies, have the potential to improve the efficacy and safety profiles of current immunotherapies.
Antigens, Surface ; metabolism ; Apoptosis Regulatory Proteins ; metabolism ; Humans ; Immunotherapy ; methods ; Macrophages ; immunology ; Neoplasms ; immunology ; pathology ; therapy ; Phagocytosis ; immunology ; Treatment Outcome ; Tumor Microenvironment ; immunology

Metastasis is the leading cause of death in breast cancer patients. However, the mechanisms underlying metastasis are not well understood and there is no effective treatment in the clinic. Here, we demonstrate that in MMTV-PyMT, a highly malignant spontaneous breast tumor model, IL-25 (also called IL-17E) was expressed by tumor-infiltrating CD4 T cells and macrophages. An IL-25 neutralization antibody, while not affecting primary tumor growth, substantially reduced lung metastasis. Inhibition of IL-25 resulted in decreased type 2 T cells and macrophages in the primary tumor microenvironments, both reported to enhance breast tumor invasion and subsequent metastasis to the lung. Taken together, our data suggest IL-25 blockade as a novel treatment for metastatic breast tumor.
Animals ; Antibodies, Neoplasm ; pharmacology ; Antibodies, Neutralizing ; pharmacology ; Breast Neoplasms ; drug therapy ; genetics ; immunology ; CD4-Positive T-Lymphocytes ; immunology ; pathology ; Female ; Humans ; Interleukin-17 ; antagonists & inhibitors ; genetics ; immunology ; Interleukins ; antagonists & inhibitors ; genetics ; immunology ; Macrophages ; immunology ; pathology ; Mammary Neoplasms, Animal ; drug therapy ; genetics ; immunology ; Mice ; Neoplasm Metastasis ; Tumor Microenvironment ; drug effects ; genetics ; immunology

Atherosclerosis is an inflammatory disease as well as a lipid disorder. Atherosclerotic plaque formed in vessel walls may cause ischemia, and the rupture of vulnerable plaque may result in fatal events, like myocardial infarction or stroke. Because morphological imaging has limitations in diagnosing vulnerable plaque, molecular imaging has been developed, in particular, the use of nuclear imaging probes. Molecular imaging targets various aspects of vulnerable plaque, such as inflammatory cell accumulation, endothelial activation, proteolysis, neoangiogenesis, hypoxia, apoptosis, and calcification. Many preclinical and clinical studies have been conducted with various imaging probes and some of them have exhibited promising results. Despite some limitations in imaging technology, molecular imaging is expected to be used both in the research and clinical fields as imaging instruments become more advanced.
Atherosclerosis/*diagnosis/pathology/radiography ; Endothelial Cells/metabolism ; Humans ; Inflammation/pathology ; Lipoproteins, LDL/metabolism ; Macrophages/immunology/metabolism ; Plaque, Atherosclerotic ; Positron-Emission Tomography ; Tomography, Emission-Computed, Single-Photon