OBJECTIVE: To investigate the potential mechanism by which electroacupuncture (EA) induces macrophage polarization to promote muscle satellite cell proliferation and differentiation, accelerating the repair of acute skeletal muscle injury. METHODS: Forty-two SPF-grade SD rats were randomly divided into three groups: a blank group (n=6), a model group (n=18), and an EA group (n=18). The model and EA groups established acute blunt contusion model of the right gastrocnemius muscle using a self-made striking device. From day 1 after modeling, rats in the EA group received EA at "Chengshan" (BL57) and "Yanglingquan" (GB34) on the right side, using disperse-dense wave with a frequency of 2 Hz/100 Hz and a current of approximately 2 mA. The EA treatment was administered once daily for 30 minutes for 3, 7, or 14 days based on the designated sampling time points. Gait analysis was performed using the Cat Walk XT^TM system. Hematoxylin-eosin (HE) staining was used to observe the morphological changes in the gastrocnemius muscle. Masson staining was applied to evaluate collagen fiber content. Immunofluorescence was used to detect the expression of proliferating cell nuclear antigen (PCNA) in muscle satellite cells. Immunohistochemistry was used to assess the expression levels of CD68 and CD206, markers of macrophages. Serum levels of pro-inflammatory cytokines (TNF-α, IL-1β) and anti-inflammatory cytokines (IL-10, IL-13) were detected using ELISA. RESULTS: Compared with the blank group, the model group showed a significant reduction in average movement speed on days 3 and 7 after modeling (P<0.05), and a decrease in the right hind limb stride length on day 3 (P<0.05). Compared with the model group, the EA group showed increased average movement speed and right hind limb stride length on day 7 (P<0.05). In the blank group, the gastrocnemius muscle on the right side showed uniform and consistent inter-fiber spacing, with neatly and regularly arranged muscle cells. In contrast, the model group exhibited enlarged inter-fiber spacing, edema, and significant infiltration of red blood cells and inflammatory cells, with progressively increasing fibrosis over time. By day 14 after modeling, the EA group showed a return to baseline levels of inflammatory cell infiltration, and the degree of fibrosis was significantly lower than that observed in the model group. Compared with the blank group, the ratio of collagen fibers in the gastrocnemius muscle of the model group increased significantly on days 3, 7, and 14 after modeling (P<0.05). Compared with the model group, the EA group exhibited a lower collagen fiber ratio on days 3, 7, and 14 (P<0.05). Compared with the blank group, PCNA positive expression in the gastrocnemius muscle of the model group was significantly increased on days 3, 7, and 14 after modeling (P<0.05). Compared with the model group, the EA group exhibited significantly higher PCNA positive expression on days 3 and 7 (P<0.05). Compared with the blank group, the model group showed a significant increase in CD68-positive macrophage expression in the gastrocnemius muscle on day 3 after modeling (P<0.05), while CD206-positive macrophage expression increased on days 3, 7, and 14 (P<0.05). Compared with the model group, CD68 expression was significantly lower in the EA group on day 3 (P<0.05), whereas CD206 expression was significantly higher on days 3 and 7 (P<0.05), peaking on day 7 with CD206 expression. Compared with the blank group, serum TNF-α levels were significantly elevated in the model group on days 3 and 7 after modeling (P<0.05), while serum IL-1β levels were increased on days 3, 7, and 14 (P<0.05). Serum IL-10 and IL-13 levels were significantly higher on day 7 after modeling (P<0.05). Compared with the model group, the EA group exhibited lower serum TNF-α level on day 3 (P<0.05) and reduced serum IL-1β levels on days 3 and 7 (P<0.05), while serum IL-10 and IL-13 levels were significantly increased on day 7 (P<0.05). CONCLUSION EA could promote the repair of acute blunt contusion-induced gastrocnemius muscle injury by regulating the proliferation and differentiation of muscle satellite cells. This process is closely related to macrophage polarization.
Animals ; Electroacupuncture ; Rats, Sprague-Dawley ; Rats ; Macrophages/immunology* ; Muscle, Skeletal/immunology* ; Male ; Humans ; Female ; Tumor Necrosis Factor-alpha/immunology* ; Cell Proliferation

Ferroptosis, an iron-dependent programmed cell death process driven by reactive oxygen species-mediated lipid peroxidation, is regulated by several metabolic processes, including iron metabolism, lipid metabolism, and redox system. Macrophages are a group of innate immune cells that are widely distributed throughout the body, and play pivotal roles in maintaining metabolic balance by its phagocytic and efferocytotic effects. There is a profound association between the biological functions of macrophage and ferroptosis. Therefore, this review aims to elucidate three key aspects of the unique relationship between macrophages and ferroptosis, including macrophage metabolism and their regulation of cellular ferroptosis; ferroptotic stress that modulates functions of macrophage and promotion of inflammation; and the effects of macrophage ferroptosis and its role in diseases. Finally, we also summarize the possible mechanisms of macrophages in regulating the ferroptosis process at the global and local levels, as well as the role of ferroptosis in the macrophage-mediated inflammatory process, to provide new therapeutic insights for a variety of diseases.
Ferroptosis/physiology* ; Macrophages/metabolism* ; Humans ; Animals ; Iron/metabolism* ; Reactive Oxygen Species/metabolism* ; Lipid Peroxidation/physiology* ; Inflammation/metabolism*

BACKGROUND: Immunosuppression is closely related to the pathogenesis of sepsis, but the underlying mechanisms have not yet been fully elucidated. In this study, we aimed to examine the role of the Sterile Alpha Motif, Src Homology 3 domain and nuclear localization signal 1 (SAMSN1) in sepsis and elucidate its potential molecular mechanism in sepsis induced immunosuppression. METHODS: RNA sequencing databases were used to validate SAMSN1 expression in sepsis. The impact of SAMSN1 on sepsis was verified using gene knockout mice. Flow cytometry was employed to delineate how SAMSN1 affects immunity in sepsis, focusing on immune cell types and T cell functions. Clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated protein 9 (Cas9)-mediated gene editing in RAW264.7 macrophages enabled interrogation of SAMSN1 's regulatory effects on essential macrophage functions, including cell proliferation and phagocytic capacity. The mechanism of SAMSN1 in the interaction between macrophages and T cells was investigated using the RAW264.7 cell line and primary cell lines. RESULTS: SAMSN1 expression was significantly increased in patients with sepsis and was positively correlated with sepsis mortality. Genetic deletion of Samsn1 in murine sepsis model improved T cell survival, elevated T cell cytolytic activity, and activated T cell signaling transduction. Concurrently, Samsn1 knockout augmented macrophage proliferation capacity and phagocytic efficiency. In macrophage, SAMSN1 binds to Kelch-like epichlorohydrin-associated protein 1 (KEAP1), causing nuclear factor erythroid 2-related factor 2 (NRF2) to dissociate from the KEAP1-NRF2 complex and translocate into the nucleus. This promotes the transcription of the coinhibitory molecules CD48/CD86/carcinoembryonic antigen related cell adhesion molecule 1 (CEACAM1), which bind to their corresponding receptors natural killer cell receptor 2B4/CD152/T cell immunoglobulin and mucin domain-containing protein 3 (TIM3) on the surface of T cells, inducing T-cell exhaustion. CONCLUSIONS SAMSN1 deletion augmented adaptive T cell immunity and macrophage phagocytic-proliferative dual function. Furthermore, it mediates the KEAP1-NRF2 axis, which affects the expression of coinhibitory molecules on macrophages, leading to T-cell exhaustion. This novel immunosuppression mechanism potentially provides a candidate molecular target for sepsis immunotherapy.
Animals ; NF-E2-Related Factor 2/metabolism* ; Mice ; Macrophages/immunology* ; Sepsis/metabolism* ; Kelch-Like ECH-Associated Protein 1/genetics* ; T-Lymphocytes/immunology* ; Humans ; Signal Transduction/physiology* ; RAW 264.7 Cells ; Mice, Knockout ; Mice, Inbred C57BL ; Male ; Flow Cytometry ; T-Cell Exhaustion

BACKGROUND: Macrophage polarization anomalies and dysfunction play a crucial role in the pathogenesis of immune thrombocytopenia (ITP). Itaconate is a Krebs cycle-derived immunometabolite synthesized by myeloid cells to modulate cellular metabolism and inflammatory responses. This study aimed to evaluate the immunoregulatory effects of an itaconate derivative on macrophages in patients with ITP. METHODS: Peripheral blood-derived macrophages from patients with ITP and healthy controls were treated with 4-octyl itaconate (4-OI), a derivative of itaconate that can penetrate the cell membrane. Macrophage polarization, antigen-presenting functions, and phagocytic capability were measured via flow cytometry and enzyme-linked immunosorbent assay (ELISA). Macrophage glycolysis in patients with ITP and the metabolic regulatory effect of 4-OI were detected using a Seahorse XFe96 Analyzer. An active murine model of ITP was used to evaluate the therapeutic effects of 4-OI in vivo . RESULTS: 4-OI reduced the levels of CD80 and CD86 in M1 macrophages and suppressed the release of tumor necrosis factor-α (TNF-α) and interleukin (IL)-6 pro-inflammatory cytokines, suggesting that 4-OI could hinder the polarization of macrophages toward an M1 phenotype. We found that 4-OI pretreated M1 macrophages reduced the proliferation of CD4 + T cells and promoted the differentiation of regulatory T cells. In addition, after 4-OI treatment, the phagocytic capacity of M1 macrophages toward antibody-coated platelets decreased significantly in patients with ITP. In addition, the glycolytic function of M1 macrophages was elevated in individuals with ITP compared to those in healthy controls. 4-OI treatment downregulated glycolysis in M1 macrophages. The glycolysis inhibitor 2-deoxy-d-glucose (2-DG) also inhibited the polarization of M1 macrophages and restored their functions. In vivo , 4-OI treatment significantly increased platelet counts in the active ITP murine model. CONCLUSIONS Itaconate derivative 4-OI inhibited M1 macrophage polarization and restored impaired functions through metabolic reprogramming. This study provides a novel therapeutic option for ITP.
Macrophages/metabolism* ; Humans ; Animals ; Succinates/pharmacology* ; Mice ; Male ; Female ; Adult ; Middle Aged ; Flow Cytometry ; Tumor Necrosis Factor-alpha/metabolism* ; Enzyme-Linked Immunosorbent Assay ; Purpura, Thrombocytopenic, Idiopathic/metabolism* ; Glycolysis/drug effects* ; Metabolic Reprogramming

OBJECTIVES: To investigate the value of peripheral blood monocyte-to-lymphocyte ratio (MLR) and neutrophil-to-lymphocyte ratio (NLR) in evaluating the severity and prognosis of pediatric viral encephalitis (VE). METHODS: A retrospective analysis was performed for the clinical data of 268 children with VE who were admitted to the Department of Pediatrics, Zhucheng People's Hospital, from February 2020 to September 2024. According to the Glasgow Coma Scale (GCS) score, the children were divided into critical group (109 children; GCS score ≤8) and non-critical group (159 children; GCS score >8). According to the results of Glasgow Outcome Scale after follow-up for six months, the children were divided into poor prognosis group (84 children; grade 1-3) and good prognosis group (184 children; grade 4-5). The influencing factors for disease severity and prognosis were analyzed, and the value of peripheral blood MLR and NLR in predicting disease severity and prognosis was assessed. RESULTS: The multivariate logistic regression analysis showed that high neutrophil (NEU) count, high MLR, high NLR, and low lymphocyte (LYM) count were closely associated with the critical condition and poor prognosis in children with VE (P<0.05). The receiver operating characteristic curve analysis showed that MLR and NLR had an area under the curve (AUC) of 0.772 and 0.883, respectively, for predicting critical illness in children with VE (P<0.05), as well as an AUC of 0.715 and 0.930, respectively, for predicting poor prognosis (P<0.05). CONCLUSIONS Peripheral blood MLR and NLR are associated with critical condition and poor prognosis and can be used as biomarkers for assessing the disease severity and prognosis in children with VE on admission.
Humans ; Prognosis ; Male ; Female ; Child, Preschool ; Child ; Retrospective Studies ; Neutrophils ; Lymphocytes ; Infant ; Encephalitis, Viral/diagnosis* ; Monocytes ; Adolescent ; Logistic Models ; ROC Curve

OBJECTIVES: To study the predictive value of serum macrophage M1/M2 markers for the risk of cardiac lesions in obese children. METHODS: A total of 60 obese children (mild-to-moderate obesity, n=32; severe obesity, n=28) and 50 healthy controls who visited the Second Affiliated Hospital of Nanchang University from June 2024 to December 2024 were included. The baseline characteristics and the levels of laboratory indicators, echocardiographic parameters, and macrophage markers (MCP-1, Arg-1, CD206, and CD86) were compared among the three groups. The correlation between macrophage marker levels and echocardiographic parameters and the influencing factors of cardiac lesions in obese children were analyzed. The receiver operating characteristic curve analysis was used to evaluate the predictive performance of each influencing factor for cardiac lesions in obese children. RESULTS: Multiple echocardiographic parameters differed significantly among the mild-to-moderate obesity, severe obesity, and control groups (P<0.01). Significant differences were also observed in MCP-1 and Arg-1 levels, CD206 positivity rate, and the CD86/CD206 ratio among the three groups (P<0.05). In obese children, MCP-1 and Arg-1 levels, as well as CD86 and CD206 positivity rates, were correlated with echocardiographic parameters (P<0.05). Univariate logistic regression identified MCP-1, Arg-1, the CD86/CD206 ratio, and the CD206 positivity rate as factors associated with cardiac lesions (P<0.05). The combined prediction model based on these markers yielded an area under the receiver operating characteristic curve of 0.887 (P<0.01). CONCLUSIONS Combined measurement of macrophage markers can predict the risk of early cardiac lesions in obese children.
Humans ; Male ; Female ; Child ; Biomarkers/blood* ; Macrophages ; Obesity/blood* ; Chemokine CCL2/blood* ; ROC Curve ; Adolescent ; Child, Preschool ; Heart Diseases/diagnosis* ; Echocardiography

Neutrophils, as the most abundant immune cells in the human body, possess the inherent ability to rapidly migrate to sites of inflammation and infection. Novel drug delivery systems leveraging neutrophils capitalize on their natural targeting and phagocytic capabilities to achieve precise drug delivery. Efficient drug loading into neutrophils within neutrophil-based delivery systems can be achieved through physical adsorption, chemical conjugation, and phagocytosis. Design strategies emphasize carrier selection and targeting ligand design to enhance delivery precision. Compared to traditional drug delivery systems, neutrophil-based systems offer significant advantages, including excellent biocompatibility and strong tissue penetration. These properties can significantly improve drug bioavailability and reduce adverse reactions associated with non-target tissue accumulation. However, these systems also face several challenges that require resolution, such as difficulties in cell collection and preservation, the need for stability optimization, challenges in large-scale production, and a lengthy clinical translation cycle. In disease treatment applications, neutrophil-based drug delivery systems enable precise delivery of anti-cancer drugs to tumor sites, potentially disrupting immunosuppression of the tumor microenvironment and enhancing therapeutic efficacy. For brain diseases, their unique ability to cross the blood-brain barrier facilitates effective drug delivery. In chronic inflammatory diseases, neutrophil-based systems can precisely deliver anti-inflammatory agents to mitigate inflammation. Performance enhancements for neutrophil-based systems can be achieved by the development of novel nanomaterials and optimization of targeting ligand affinity, thereby improving the accuracy and efficiency of drug delivery. This review comprehensively explores the design strategies, advantages, challenges, and future directions of neutrophil-based drug delivery systems. It summarizes research progress in disease treatment applica-tions, aiming to offer key insights for the development of novel drug delivery systems and advance precision medicine and targeted therapy.
Humans ; Drug Delivery Systems/methods* ; Neutrophils ; Phagocytosis ; Drug Carriers ; Blood-Brain Barrier ; Neoplasms/drug therapy*

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

OBJECTIVE: To study the expression of SPOP in patients with acute myeloid leukemia (AML) and its effect on proliferation, apoptosis and cycle of AML cells. METHODS: RT-qPCR was used to detect the expression of SPOP mRNA in bone marrow samples of patients with newly diagnosed AML and normal controls. The stable overexpression of SPOP in AML cell lines THP-1 and U937 were constructed by liposome transfection. The effect of SPOP on cell proliferation was detected by CCK-8, and the effect of SPOP on apoptosis and cell cycle was detected by flow cytometry. The expressions of anti-apoptotic protein Bcl-2 and apoptotic protein Bax, Caspase3 were detected by Western blot. RESULTS: The median expression level of SPOP mRNA in normal control group was 0.993 1(0.6303, 1.433), while that in AML group was 0.522 1(0.242 2, 0.723 7). The expression level of SPOP in AML group was significantly lower than that in normal control group ( P < 0.001). After the overexpression of SPOP, the proportion of apoptotic cells in the U937 overexpression group and THP-1 overexpression group was 10.9%±0.3% and 4.6%±015%, which were higher than 8.9%±0.3% and 3.0%±0.30% in the Empty Vector group, respectively (both P < 0.05). The expression of Caspase3 in U937 overexpression group and THP-1 overexpression group was 1.154±0.086 and 1.2±0.077, which were higher than 1 in Empty Vector group, respectively (both P < 0.05). The ratio of Bax/Bcl-2 in U937 overexpression group and THP-1 overexpression group was 1.328±0.057 and 1.669±0.15, which were higher than 1 in Empty Vector group, respectively (both P < 0.05). In the cell proliferation experiment, the number of cells in the U937 overexpression group and THP-1 overexpression group were both slightly lower than those in the Empty Vector group, but the differences were not statistically significant (P >0.05). In the cell cycle experiment, the proportion of G₁ cells in the U937 overexpression group and THP-1 overexpression group were both slightly higher than those in the Empty Vector group, but the differences were not statistically significant (P >0.05). CONCLUSION SPOP can promote the apoptosis of leukemic cells, and its mechanism may be related to down-regulation of Bcl-2 expression and up-regulation of Bax and Caspase3 expression.
Humans ; Leukemia, Myeloid, Acute/pathology* ; Apoptosis ; Repressor Proteins/genetics* ; Cell Proliferation ; Nuclear Proteins/genetics* ; Cell Cycle ; Proto-Oncogene Proteins c-bcl-2/metabolism* ; Caspase 3/metabolism* ; bcl-2-Associated X Protein/metabolism* ; U937 Cells ; Cell Line, Tumor ; RNA, Messenger/genetics*

Bone marrow microenvironment is the environment in which hematopoietic stem cells live, mainly composed of bone marrow stromal cells, microvessels, nerves, and cytokines secreted by stromal cells. The bone marrow microenvironment plays a crucial role in the self-renewal, directed differentiation and proliferation of hematopoietic stem cells and the regulation of proliferation, differentiation and maturation of hematopoietic cells. A class of macrophages exists in the bone marrow microenvironment, the bone marrow-resident tissue macrophages, which plays a crucial role in maintaining homeostasis in vivo, and three subpopulations of bone marrow-resident tissue macrophages have been characterized: erythroblastic island macrophages (EIMs), hematopoietic stem cell niche macrophages, and bone macrophages. This review focuses on the functions, surface markers and modeling of EIMs.
Macrophages/cytology* ; Humans ; Erythroblasts/cytology* ; Animals ; Hematopoietic Stem Cells/cytology*