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

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*

Intervertebral disc degeneration (IDD) is the main cause of low back pain. Immune cells play an extremely important role in regulating the progression of IDD by interacting with nucleus pulposus (NP) cells and the extracellular matrix (ECM). Healthy NP tissue is a vascular-free and immune-privileged tissue that does not normally interact with macrophages. However, the establishment of neovascularization channels in damaged intervertebral discs has led to extensive cross-talk between NP and macrophages, with different results depending on microenvironmental stimuli. Based on this, this review reviewed the correlation between IDD and low back pain, summarized the source and function of macrophages, and discussed the possible regulatory mechanism between macrophages and discogenic pain. Finally, potential therapies targeting macrophages to delay IDD in recent years were also discussed, aiming to emphasize the important role of immunology in IDD and provide a new direction for the prevention and treatment of IDD.
Humans ; Intervertebral Disc Degeneration/complications* ; Macrophages/immunology* ; Low Back Pain/immunology* ; Nucleus Pulposus ; Animals ; Extracellular Matrix

Eight butyl-phthalides, senkyunolide K(1), senkyunolide N(2), butylphthalide(3), senkyunolide I(4), senkyunolide H(5),(Z)-butylidenephthalide(6),(Z)-ligustilide(7), and 3-butylidene-7-hydroxyphthalide(8) were isolated from the aerial part of Ligusticum sinense by column chromatography on silica gel column, ODS, Sephadex LH-20 and semi-preparative HPLC. Their structures were elucidated on the basis of spectroscopic and chemical data, especially NMR and MS. Compound 1 was a new butyl-phthalide and compounds 2-8 were isolated from the aerial part of L. sinense for the first time. Furthermore, the inhibitory activities of compounds 1-8 against the nitric oxide(NO) production induced by lipopolysaccharide(LPS) in mouse RAW264.7 macrophages in vitro were evaluated. The results showed that compounds 1-8 exerted inhibitory activities on NO production with IC_(50) of 19.34-42.16 μmol·L~(-1).
Animals ; Mice ; Nitric Oxide/biosynthesis* ; Ligusticum/chemistry* ; Benzofurans/isolation & purification* ; Drugs, Chinese Herbal/isolation & purification* ; Macrophages/immunology* ; RAW 264.7 Cells ; Molecular Structure

Metabolic diseases have seen a steady increase in incidence in recent years, becoming one of the main causes of sub-health status globally. Neutrophil extracellular traps(NETs) are reticular complexes containing DNA, which trap foreign microorganisms or induce an immune response. Current research indicates that NETs are widely active in various metabolic diseases and can cause severe damage to the body through multiple mechanisms, including promoting blood glucose elevation, damaging vascular endothelial cells, forming vascular embolisms, triggering intense inflammation, and promoting lipid accumulation. Therefore, intervening in NETs is an important approach to treating metabolic diseases. Research has shown a close relationship between the theory of spleen heat-turbid toxin theory and metabolic diseases-NETs mechanism. The basic pathogenesis include the internal accumulation of phlegm-dampness, qi stagnation and blood stasis, internal accumulation of dampness-heat, phlegm and blood stasis, and flourishing toxic heat. Various Chinese herbal medicines with the functions of dispelling dampness, resolving phlegm, promoting blood circulation to remove blood stasis, and clearing heat and toxins, along with their extracts and compound prescriptions, can treat metabolic diseases by regulating NETs and delaying disease progression. This paper systematically outlined the formation mechanisms of NETs, their connection to metabolic diseases, the theoretical basis in TCM, their roles in numerous metabolic diseases, and the current research status of TCM in regulating NETs to prevent and control metabolic diseases, aiming to provide effective reference ideas for developing therapeutic strategies for metabolic diseases.
Humans ; Extracellular Traps/metabolism* ; Metabolic Diseases/metabolism* ; Drugs, Chinese Herbal/therapeutic use* ; Animals ; Neutrophils/metabolism* ; Medicine, Chinese Traditional

Network pharmacology and molecular docking were employed to predict the mechanism of Zhizhu Decoction in regulating macrophage polarization to reduce adipose tissue inflammation in obese children, and animal experiments were then carried out to validate the prediction results. The active ingredients and targets of Zhizhu Decoction were retrieved from the Traditional Chinese Medicine Systems Pharmacology Database and Analysis Platform(TCMSP). The inflammation related targets in the adipose tissue of obese children were searched against GeneCards, OMIM, and DisGeNET, and a drug-disease-target network was established. STRING was used to construct a protein-protein interaction(PPI) network and screen for core targets. R language was used to carry out Gene Ontology(GO) and Kyoto Encyclopedia of Genes and Genomes(KEGG) pathway enrichment analyses. AutoDock was used for the molecular docking between core targets and active ingredients. 24 SPF grade 6-week C57B/6J male mice were adaptively fed for 1 week, and 8 mice were randomly selected as the blank group. The remaining 16 mice were fed with high-fat diet for 8 weeks to onstruct a high-fat diet induced mouse obesity model. After successful modeling, the 16 mice were randomly divided into model group and Zhizhu Decoction group, with 8 mice in each group. Zhizhu Decoction group was intervened by gavage for 14 days, once a day. Blank group and model group were given an equal amount of sterile double distilled water(ddH_2O) by gavage daily. After the last gavage, serum and inguinal adipose tissue were collected from mice for testing. The morphology of inguinal adipose tissue was observed by hematoxylin-eosin(HE) staining, the levels of inflammatory factors interleukin-6(IL-6) and tumor necrosis factor-α(TNF-α)were detected by enzyme-linked immunosorbent assay(ELISA), and the protein expression of macrophage marker molecule nitric oxide synthase(iNOS) and epidermal growth factor like hormone receptor 1(F4/80) was detected by immunofluorescence staining. Network pharmacology predicted luteolin, naringenin, and nobiletin as the main active ingredients in Zhizhu Decoction and 15 core targets. KEGG pathway enrichment analysis revealed involvement in the key signaling pathway of nuclear factor κB(NF-κB). Molecular docking showed that the active ingredients of Zhizhu Decoction bound well to the core targets. Animal experiment showed that compared with the model group, Zhizhu Decoction reduced the distribution of inflammatory cytokines in the inguinal adipose tissue of mice, lowered the levels of TNF-α and IL-6 in the serum(P<0.05, P<0.01), and down-regulated the expression of iNOS and F4/80(P<0.05). The results showed that the active ingredients in Zhizhu Decoction, such as luteolin, naringenin, and nobiletin, inhibit the aggregation of macrophages in adipose tissue, downregulate their classic activated macrophage(M1) polarization, reduce the expression of inflammatory factors IL-6 and TNF-α, and thus improve adipose tissue inflammation in obese mice.
Animals ; Drugs, Chinese Herbal/pharmacology* ; Molecular Docking Simulation ; Adipose Tissue/immunology* ; Mice ; Male ; Humans ; Network Pharmacology ; Macrophages/immunology* ; Mice, Inbred C57BL ; Child ; Protein Interaction Maps/drug effects* ; Obesity/genetics* ; Inflammation/drug therapy*