Macrophages derived from the human THP-1 cell line have been widely used as substitutes for primary macrophages in various macrophage-related studies. However, difficulties still exist in establishing THP-1 macrophage models. This research presents techniques for generating different phenotypes of activated macrophages derived from THP-1 cells by introducing specific stimuli and provides some potential markers to confirm each type of activated macrophage. It is hoped to provide novel and useful methods for scientific research and to help researchers explore this field more intuitively and effectively.
Humans ; Macrophages/physiology* ; THP-1 Cells ; Cell Culture Techniques/methods* ; Macrophage Activation ; Cell Polarity ; Cell Differentiation ; Phenotype ; Cell Line

OBJECTIVES: To investigate the effect of high glucose on macrophage polarization and the role of immune-responsive gene 1 (IRG1) in mediating its effect. METHODS: RAW264.7 cells were transfected with IRG1-overexpressing plasmid or IRG1 siRNA via electroporation and cultured in either normal or high glucose for 72 h to observe the changes in cell viability and morphology using CCK-8 assay and phase contrast microscopy. The protein levels of IRG1, iNOS, Arg-1, IL-1β and IL-10 in the treated cells were detected with Western blotting, and the fluorescence intensities of iNOS and Arg-1 were detected using immunofluorescence assay. The protein levels of IL-1β and IL-10 in the culture medium were determined with ELISA. RESULTS: High glucose exposure significantly reduced IRG1 and Arg-1 expressions, increased iNOS and IL-1β expressions and IL-1β secretion, and decreased IL-10 level in RAW264.7 cells. Transfection with the IRG1-overexpressing plasmid provided the cells with obvious resistance to high glucose-induced changes in iNOS, Arg-1, IL-1β and IL-10, whereas IRG1 knockdown further enhanced the effects of high glucose exposure on Arg-1 expression and the expression and secretion of IL-10. CONCLUSIONS High glucose promotes M1 polarization of the macrophages possibly through a mechanism to inhibit the expression of IRG1 protein, thus leading to chronic inflammatory response.
Animals ; Mice ; Macrophages/drug effects* ; Glucose/pharmacology* ; Interleukin-10/metabolism* ; Nitric Oxide Synthase Type II/metabolism* ; RAW 264.7 Cells ; Interleukin-1beta/metabolism* ; Arginase/metabolism* ; RNA, Small Interfering/genetics* ; Transfection ; Inflammation

OBJECTIVES: To explore the active components that mediate the therapeutic effect of Centella asiatica on psoriasis and their therapeutic mechanisms. METHODS: TCMSP, TCMIP, PharmMapper, Swiss Target Prediction, GeneCards, OMIM and TTD databases were searched for the compounds in Centella asiatica and their targets and the disease targets of psoriasis. A drug-active component-target network and the protein-protein interaction network were constructed, and DAVID database was used for pathway enrichment analysis. In a RAW264.7 macrophage model of LPS-induced inflammation, the anti-inflammatory effect of 7.5, 15, 30, and 60 μmol/L quercetin, asiaticoside, and asiatic acid, which were identified as the main active components in Centella asiatica, were tested by measuring cellular production of NO, TNF‑α and IL-6 using Griess method and ELISA and by detecting mRNA expressions of IL-23, IL-17A, TNF-α and IL-6 and protein expressions of p-STAT3 (Tyr705) and p-STAT3 (Ser727) with RT-qPCR and Western blotting. RESULTS: A total of 139 targets of Centella asiatica and 4604 targets of psoriasis were obtained, and among them CASP3, EGFR, PTGS2, and ESR1 were identified as the core targets. KEGG analysis suggested that quercetin, asiaticoside, and asiatic acid in Centella asiatica were involved in cancer and IL-17 and MAPK signaling pathways. In the RAW264.7 macrophage model of inflammation, treatment with quercetin significantly reduced cellular production of NO, TNF‑α and IL-6, and lowered mRNA expressions of IL-23, IL-17A, TNF‑α and IL-6 and protein expressions of p-STAT3 (Tyr705) and p-STAT3 (Ser727). CONCLUSIONS Quercetin, asiaticoside and asiatic acid are the main active components in Centella asiatica to mediate the therapeutic effect against psoriasis, and quercetin in particular is capable of suppressing cellular production of NO, TNF‑α and IL-6 and regulating the IL-23/IL-17A inflammatory axis by mediating STAT3 phosphorylation to inhibit inflammatory response.
Quercetin/pharmacology* ; Psoriasis/metabolism* ; STAT3 Transcription Factor/metabolism* ; Mice ; Animals ; Centella/chemistry* ; Triterpenes/pharmacology* ; Phosphorylation ; Interleukin-17/metabolism* ; Interleukin-23/metabolism* ; RAW 264.7 Cells ; Pentacyclic Triterpenes/pharmacology* ; Macrophages/drug effects* ; Signal Transduction ; Plant Extracts

OBJECTIVES: To investigate the clinical significance of SLC1A5 overexpression in pan-cancer and its mechanism for promoting hepatocellular carcinoma (HCC) progression. METHODS: We analyzed the correlation of SLC1A5 expression with clinical stage, lymph node metastasis and prognosis in pan-cancer using TCGA and ICGC datasets and explored its association with immune cell infiltration using EPIC, CIBERSORT, and TIMER algorithms. In HCC cell lines, the effects of lentivirus-mediated SLC1A5 overexpression or RNA interference on cell proliferation were examined using CCK-8 assay, and the growth of HCC cell xenografts overexpressing SLC1A5 was observed in nude mice. The effects of SLC1A5 overexpression or silencing in HCC cells on macrophage polarization were evaluated in a cell co-culture system. RESULTS: SLC1A5 was mainly localized on cell membrane and was highly expressed in most cancers in association with clinical stage, lymph node metastasis and poor prognosis. SLC1A5 expression was positively correlated with immunity score in 13 cancer types, especially in low-grade glioma (LGG), LIHC and thyroid cancer. SLC1A5 was positively correlated with macrophage infiltration level in LGG and LIHC but negatively correlated with macrophage infiltration in 5 cancers including lung squamous carcinoma, pancreatic carcinoma, and gastric carcinoma. Patients with SLC1A5 overexpression and high level of M2 macrophage infiltration had the worst survival outcomes. SLC1A5 was correlated with immunosuppression-related genes, cytokines, and cytokine receptors, which was the most obvious in LGG and LIHC. SLC1A5 was highly expressed in different HCC cell lines, and its overexpression promoted HCC cell proliferation both in vitro and in nude mice. In the cell co-culture experiment, SLC1A5 was positively correlated with the molecular markers of M2 polarization of macrophages, and its overexpression strongly promoted M2 polarization of the macrophages and inhibited T cell secretion of IFN-γ. CONCLUSIONS SLC1A5 expression level is correlated with clinical stage, lymph node metastasis, prognosis, and immune cell infiltration in most cancers, and its overexpression promotes HCC progression by inhibiting T-cell function via promoting M2 polarization of macrophages.
Humans ; Carcinoma, Hepatocellular/metabolism* ; Liver Neoplasms/metabolism* ; Animals ; Macrophages/cytology* ; Disease Progression ; Cell Line, Tumor ; Mice ; Amino Acid Transport System ASC/genetics* ; Cell Proliferation ; Lymphatic Metastasis ; Mice, Nude ; Prognosis ; Minor Histocompatibility Antigens

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

Atherosclerosis (AS) is a prevalent clinical vascular condition and serves as a pivotal pathological foundation for cardiovascular diseases. Understanding the pathogenesis of AS has significant clinical and societal implications, aiding in the development of targeted drugs. Neutrophils, the most abundant leukocytes in circulation, assume a central role during inflammatory responses and closely interact with AS, which is a chronic inflammatory vascular disease. Neutrophil extracellular traps (NETs) are substantial reticular formations discharged by neutrophils that serve as an immune defense mechanism. These structures play a crucial role in inducing dysfunction of the vascular barrier following endothelial cell injury. Components released by NETs pose a threat to the integrity of vascular endothelium, which is essential as it acts as the primary barrier to maintain vascular wall integrity. Endothelial damage constitutes the initial stage in the onset of AS. Recent investigations have explored the intricate involvement of NETs in AS progression. The underlying structures of NETs and their active ingredients, including histone, myeloperoxidase (MPO), cathepsin G, neutrophil elastase (NE), matrix metalloproteinases (MMPs), antimicrobial peptide LL-37, alpha-defensin 1-3, and high mobility group protein B1 have diverse and complex effects on AS through various mechanisms. This review aims to comprehensively examine the interplay between NETs and AS while providing insights into their mechanistic underpinnings of NETs in this condition. By shedding light on this intricate relationship, this exploration paves the way for future investigations into NETs while guiding clinical translation efforts and charting new paths for therapeutic interventions.
Extracellular Traps/physiology* ; Humans ; Atherosclerosis/immunology* ; Neutrophils/physiology* ; Leukocyte Elastase/metabolism* ; Peroxidase/physiology* ; Matrix Metalloproteinases/physiology* ; Cathepsin G/metabolism* ; Cathelicidins ; HMGB1 Protein/physiology* ; Histones ; Animals ; Endothelium, Vascular

Malignant proliferating liver cancer cells possess the ability to detect and respond to various body signals, thereby facilitating tumor growth, invasion, and metastasis. One crucial mechanism through which hepatocellular carcinoma (HCC) cells interpret these signals is crosstalk. Within liver cancer tissues, cancer cells engage in communication with hepatic stellate cells (HSCs), tumor-associated macrophages (TAMs), and immune cells. This interaction plays a pivotal role in regulating the proliferation, invasion, and metastasis of HCC cells. Crosstalk occurs in multiple ways, each characterized by distinct functions. Its molecular mechanisms primarily involve regulating immune cell functions through the expression of specific receptors, such as CD24 and CD47, modulating cell functions by secreting cytokines like transforming growth factor-β (TGF-β) and platelet-derived growth factor (PDGF), and mediating cell growth and proliferation by activating pathways such as Wnt/β-catenin and Hedgehog. A comprehensive understanding of the mechanisms and interactions within crosstalk is essential for unraveling the pathogenesis of HCC. It also opens up new avenues for the development of innovative therapeutic strategies. This article reviews the relationship between crosstalk and the progression of HCC, offering insights and inspiration for future research.
Humans ; Carcinoma, Hepatocellular/metabolism* ; Liver Neoplasms/metabolism* ; Hepatic Stellate Cells/physiology* ; Disease Progression ; Signal Transduction/physiology* ; Transforming Growth Factor beta/metabolism* ; Cell Proliferation ; Hedgehog Proteins/metabolism* ; Tumor-Associated Macrophages ; Platelet-Derived Growth Factor/metabolism* ; Cell Communication/physiology*

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