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

This study delves into the mechanism of total flavone of Abelmoschus manihot(TFA) in treating ulcerative colitis(UC) and depression via inhibiting M1 polarization of macrophages and reshaping intestinal flora and glycerolphospholipid metabolism. The study established a mouse model of UC and depression induced by chronic restraint stress(CRS) and dextran sulfate sodium(DSS). The fecal microbiota transplantation(FMT) experiment after TFA intervention was conducted. Mice in the FMT donor group were modeled and treated, and fecal samples were taken to prepare the bacterial solution. Mice in the FMT receptor group were treated with antibiotic intervention, and then administered bacterial solution by gavage from mice in the donor group, followed by UC depression modeling. After the experiment, behavioral tests were conducted to evaluate depressive-like behaviors by measuring the levels of 5-hydroxytryptamine(5-HT) and brain-derived neurotrophic factor(BDNF) in the hippocampus of mice. The levels of tumor necrosis factor-α(TNF-α),interleukin-6(IL-6),and interleukin-1β(IL-1β)in the brain and colon tissue of mice were also measured, and the polarization status of macrophages was evaluated by measuring the mRNA levels of CD86 and CD206. 16S ribosomal RNA(16S rRNA) sequencing technology was used to analyze changes in the intestinal flora of mice. Wide target lipidomics was used to detect serum lipid metabolite levels in mice after FMT,and correlation analysis was conducted between lipids and differential intestinal flora significantly regulated by TFA. In vitro experiments, representative glycerophospholipid metabolites and glycerophospholipid inhibitors were used to intervene in Raw264.7 macrophages, and the mRNA levels of TNF-α,IL-6,IL-1β,CD86,and CD206 were detected. The results showed that TFA and FMT after intervention could significantly improve depressive-like behavior and intestinal inflammation in mice with UC and depression, significantly downregulate pro-inflammatory cytokines and CD86 mRNA expression in brain and colon tissue, inhibiting M1 polarization of macrophages, and significantly upregulate CD206 mRNA expression, promoting M2 polarization of macrophages. In addition, the high-dose group had a more significant effect. After TFA intervention, FMT significantly corrected the metabolic disorder of glycerophospholipids in mice with UC and depression, and there was a significant correlation between differential intestinal flora and glycerophospholipids. In vitro experiments showed that glycerophospholipid metabolites, especially lysophosphatidylcholine(LPC),significantly upregulated pro-inflammatory cytokines and CD86 mRNA expression, promote M1 polarization of macrophages, while glycerophospholipid inhibitors had the opposite effect. The results indicate that TFA effectively treats depression and UC by correcting intestinal flora dysbiosis and reshaping glycerophospholipid metabolism, thereby inhibiting M1 polarization of macrophages.
Animals ; Mice ; Gastrointestinal Microbiome/drug effects* ; Abelmoschus/chemistry* ; Macrophages/metabolism* ; Colitis, Ulcerative/immunology* ; Flavones/administration & dosage* ; Male ; Depression/genetics* ; Glycerophospholipids/metabolism* ; Humans ; Drugs, Chinese Herbal/administration & dosage* ; Mice, Inbred C57BL

The chemical constituents were systematically separated from the roots of Berberis polyantha by various chromatographic methods, including silica gel column chromatography, HP20 column chromatography, polyamide column chromatography, reversed-phase C_(18) column chromatography, and preparative high-performance liquid chromatography. The structures of the compounds were identified by physicochemical properties and spectroscopic techniques(1D NMR, 2D NMR, UV, MS, and CD). Four phenylpropanoids were isolated from the methanol extract of the roots of B. polyantha, and they were identified as(2R)-1-(4-hydroxy-3,5-dimethoxyphenyl)-1-propanone-O-β-D-glucopyranoside(1), methyl 4-hydroxy-3,5-dimethoxybenzoate(2),(+)-syringaresinol(3), and syringaresinol-4-O-β-D-glucopyranoside(4). Compound 1 was a new compound, and other compounds were isolated from this plant for the first time. The anti-inflammatory activity of these compounds was evaluated based on the release of nitric oxide(NO) in the culture of lipopolysaccharide(LPS)-induced RAW264.7 macrophages. At a concentration of 10 μmol·L~(-1), all the four compounds inhibited the LPS-induced release of NO in RAW264.7 cells, demonstrating potential anti-inflammatory properties.
Plant Roots/chemistry* ; Animals ; Mice ; Berberis/chemistry* ; RAW 264.7 Cells ; Macrophages/immunology* ; Drugs, Chinese Herbal/isolation & purification* ; Nitric Oxide/metabolism* ; Molecular Structure ; Anti-Inflammatory Agents/isolation & purification*

To investigate the mechanism of Jianpi Qutan Formula in regulating the balance between classically activated macrophages(M1) and alternatively activated macrophages(M2) in atherosclerotic plaques through phosphorylation and activation of the signal transducer and activator of transcription 6(STAT6), thereby reducing inflammation, increasing plaque stability, and exerting anti-atherosclerosis(AS) effects. An AS model was established by feeding apolipoprotein E(ApoE)~(-/-) mice with atherosclerotic chow for 8 weeks. The ApoE~(-/-) mice were randomly divided into a model group(Mod group), a Jianpi Qutan Formula group(JPQT group, 8.97 g·kg~(-1)), and a Atorvastatin Calcium Tablets group(ATO group, 1.3 mg·kg~(-1)) according to a random table method, with 10 mice in each group. Additionally, 10 male C57BL/6J mice of the same age, fed with a normal diet, were set as the control group(Con group). The JPQT and ATO groups received their respective treatments via oral gavage for 8 consecutive weeks, while the Con and Mod groups were administered an equivalent volume of saline. Body weight was continuously monitored, and after blood collection, total cholesterol(TC) and triglyceride(TG) levels in the serum of each group were compared. Hematoxylin-eosin(HE) staining and oil red O staining were used to observe plaque formation in aortic tissue. Enzyme-linked immunosorbent assay(ELISA) was employed to detect the expression levels of pro-inflammatory cytokines interleukin(IL)-6 and IL-12, as well as the anti-inflammatory cytokine IL-10. Immunofluorescence was used to detect the positive expression of aortic cluster of differentiation(CD)86 and CD206. Western blot analysis was conducted to detect the protein expression levels of aortic inducible nitric oxide synthase(iNOS), arginase 1(Arg1), STAT6, and p-STAT6. Compared to the Con group, the Mod group exhibited increased body weight and blood lipid levels, disordered aortic structure, significant AS plaque formation accompanied by extensive lipid deposition, and elevated serum levels of pro-inflammatory cytokines IL-6 and IL-12, as well as elevated CD86 and iNOS protein levels. In contrast, the serum levels of the anti-inflammatory cytokine IL-10, along with the protein expression levels of CD206, Arg1, and p-STAT6/STAT6, were reduced. Compared to the Mod group, the drug intervention groups showed improvements in body weight and lipid metabolism, with a more significant improvement in aortic structure, reduced lipid accumulation, decreased serum levels of IL-6 and IL-12, and lower CD86 and iNOS protein levels. Meanwhile, levels of IL-10, CD206, Arg1, and p-STAT6/STAT6 increased. Jianpi Qutan Formula improves AS by regulating the imbalance in M1/M2 macrophage polarization, and its mechanism is likely closely related to the activation of the STAT6 signaling pathway.
Animals ; Atherosclerosis/metabolism* ; Male ; Drugs, Chinese Herbal/administration & dosage* ; Mice ; Macrophages/cytology* ; Mice, Inbred C57BL ; STAT6 Transcription Factor/immunology* ; Humans ; Apolipoproteins E/genetics* ; Interleukin-6/immunology*

Macroporous resin adsorption column chromatography, silica gel column chromatography, ODS column chromatography, and semi-preparative high-performance liquid chromatography, combined with analytical methods such as NMR and MS, were employed to separate and identify compounds from the 70% ethanol extract of Ajania purpurea. A total of 30 compounds were isolated and identified, including 13 phenolic acids, 7 coumarins, 2 lignans, 1 flavonoid, 2 sesquiterpenes, 1 steroid, and 4 others. Among them, compounds 1 and 2 were newly discovered compounds, and compounds 4, 6, 8, 12, 14-23, 25, 28, and 30 were isolated from Ajania plants for the first time. Bioactivity screening showed that multiple compounds significantly inhibited the production of nitric oxide in lipopolysaccharide-stimulated RAW264.7 cells in a dose-dependent manner. Furthermore, compound 2 elevated the levels of glutathione in LPS-induced BEAS-2B cells, reduced the expression of pro-inflammatory cytokines such as tumor necrosis factor(TNF)-α, interleukin(IL)-6, and IL-1β, enhanced the mRNA of GPX4, HMOX1, NFE2L2, and enhanced protein levels of GPX4, HO-1, Nrf2, and SLC7A11, demonstrating potential anti-ferroptotic effect.
Mice ; Animals ; Lignans/isolation & purification* ; RAW 264.7 Cells ; Humans ; Nitric Oxide ; Tumor Necrosis Factor-alpha/immunology* ; Drugs, Chinese Herbal/isolation & purification* ; NF-E2-Related Factor 2/metabolism* ; Macrophages/metabolism* ; Interleukin-6/immunology*

A variety of chromatographic techniques, including silica gel, ODS, Sephadex LH-20, and HPLC, were employed to isolate and purify the fermentation products of rice with Monascus sanguineus. A total of 38 compounds were isolated, and their structures were identified by UV, IR, NMR, MS, calculated ECD, and comparison with literature data. Compounds 1-4 were identified as new natural products, and other compounds were isolated from this fungus for the first time. A RAW264.7 macrophage model of lipopolysaccharide(LPS)-induced inflammation was used to evaluate the anti-inflammatory activities of all the compounds. The results showed that compound 6 exhibited a certain inhibitory effect on the production of nitric oxide in LPS-induced RAW264.7 cells, with an inhibition rate of 53.08%.
Monascus/chemistry* ; Mice ; Animals ; Anti-Inflammatory Agents/isolation & purification* ; RAW 264.7 Cells ; Macrophages/immunology* ; Nitric Oxide/immunology* ; Oryza/metabolism* ; Fermentation

This study investigated the protective effect of arbutin(Arb) in yam on lipopolysaccharide(LPS)-induced acute lung injury(ALI) in a mouse model and revealed its possible mechanism of action by metabolomics technology, providing a theoretical basis for clinical treatment of ALI. SPF BALB/c mice were randomly divided into normal control group, model group, resveratrol(Rv)-positive control group, Arb low-dose(15 mg·kg~(-1)) group, and Arb high-dose(30 mg·kg~(-1)) group. The LPS-induced ALI model was established in all groups except the normal control group. Hematoxylin-eosin(HE) staining, TUNEL staining, and WBP whole-body non-invasive pulmonary function testing were used to evaluate the degree of lung tissue damage and lung function changes. Enzyme-linked immunosorbent assay(ELISA) was used to detect the level of inflammatory factors in lung tissue. Flow cytometry was used to analyze the M1/M2 polarization status of macrophages in lung tissue. Western blot was used to detect the expression levels of the TLR4 signaling pathway and related apoptotic proteins. Liquid chromatograph-mass spectrometer(LC-MS) metabolomics was used to analyze the changes in serum metabolic profile after Arb intervention. The results showed that Arb pretreatment significantly alleviated LPS-induced lung tissue injury, improved lung function, reduced the levels of pro-inflammatory factors(IL-6, TNF-α, IL-18, and IL-1β), and regulated the polarization status of M1/M2 macrophages. In addition, Arb inhibited the activation of the TLR4 signaling pathway, reduced the expression of pro-apoptotic proteins such as Bax, caspase-3, and caspase-9, up-regulated the level of Bcl-2 protein, and inhibited apoptosis of lung cells. Metabolomic analysis showed that Arb significantly improved LPS-induced metabolic abnormalities, mainly involving key pathways such as galactose metabolism, phenylalanine metabolism, and lipid metabolism. In summary, Arb can significantly reduce LPS-induced ALI by regulating the release of inflammatory factors, inhibiting the activation of the TLR4 signaling pathway, improving metabolic disorders, and regulating macrophage polarization, indicating that Arb has potential clinical application value.
Animals ; Acute Lung Injury/chemically induced* ; Mice ; Mice, Inbred BALB C ; Arbutin/administration & dosage* ; Male ; Toll-Like Receptor 4/immunology* ; Apoptosis/drug effects* ; Lung/metabolism* ; Signal Transduction/drug effects* ; Protective Agents/administration & dosage* ; Humans ; Macrophages/immunology* ; Drugs, Chinese Herbal/administration & dosage*

Allergic rhinitis (AR) is a chronic non-specific inflammatory disease of the nasal mucosa caused by abnormal activation of the immune system, with alterations in macrophage polarization playing a crucial role in its occurrence and development. Non-coding RNA has been found to play a key role in the polarization of macrophages. This study aims to explore the latest developments in research on the role of non-coding RNA-regulated macrophage polarization in the pathogenesis of AR, with the goal of identifying new approaches and potential targets for the diagnosis and treatment of AR.
Humans ; Rhinitis, Allergic/immunology* ; Macrophages/metabolism* ; RNA, Untranslated/genetics* ; Animals ; Macrophage Activation/genetics* ; Cell Polarity/genetics*

Objective To investigate the effects of hyaluronic acid and proteoglycan-linked protein 1 (HAPLN1) secreted by synovial fibroblasts (FLS) on the polarization of macrophages (Mϕ) in rheumatoid arthritis (RA). Methods Human monocytic leukemia cells (THP-1) were differentiated into Mϕ, which were subsequently exposed to recombinant HAPLN1 (rHAPLN1). RA-FLS were transfected separately with HAPLN1 overexpression plasmid (HAPLN1^OE) or small interfering RNA targeting HAPLN1 (si-HAPLN1), and then co-cultured with Mϕ to establish a co-culture model. The viability of Mϕ was assessed using the CCK-8 assay, and the proportions of pro-inflammatory M1-type and anti-inflammatory M2-type Mϕ were analyzed by flow cytometry. Additionally, the expression levels of inflammatory markers, including interleukin 1β (IL-1β), tumor necrosis factor α (TNF-α), and inducible nitric oxide synthase (iNOS), were quantified using quantitative real-time PCR and Western blot analysis. Results The viability of Mϕ was increased in the rHAPLN1 group compared to the control group. Furthermore, both the M1/Mϕ ratio and inflammatory factor levels were elevated in the rHAPLN1 and HAPLN1^OE groups. In contrast, the si-HAPLN1 group exhibited a decrease in the M1/Mϕ ratio and inflammatory factor expression. Notably, the introduction of rHAPLN1 in rescue experiments further promoted Mϕ polarization towards the M1 phenotype. Conclusion HAPLN1, secreted by RA fibroblast-like synoviocytes (RA-FLS), enhances Mϕ polarization towards the M1 phenotype.
Humans ; Arthritis, Rheumatoid/genetics* ; Macrophages/immunology* ; Fibroblasts/metabolism* ; Phenotype ; Extracellular Matrix Proteins/genetics* ; Proteoglycans/genetics* ; Synovial Membrane/cytology* ; Tumor Necrosis Factor-alpha/genetics* ; Interleukin-1beta/genetics* ; Nitric Oxide Synthase Type II/genetics* ; Cell Differentiation ; Coculture Techniques ; THP-1 Cells

Macrophages are the crucial immune cells integral to host defense and the regulation of homeostasis, exhibiting remarkable plasticity across various tissues. Upon exposure to different stimuli, they can polarize into functional subsets. The reorganization process of cellular metabolism, known as metabolic reprogramming, involves the comprehensive adjustment of intracellular metabolites, enzymes, and metabolic pathways. Recent studies have revealed the critical role of metabolic reprogramming in shaping the phenotypes and functions of macrophages. Metabolism drives and regulates macrophages by generating bioenergy and biosynthetic precursors and by altering metabolites that affect gene expression and signal transduction. This review focuses on the immunomodulatory roles of key enzymes and specific products in major metabolic pathways, such as glucose metabolism, lipid metabolism and amino acid metabolism, in macrophages. Additionally, it will highlight recent advancements in targeting metabolic regulation of macrophages in the context of ocular diseases.
Humans ; Macrophages/immunology* ; Animals ; Eye Diseases/immunology* ; Lipid Metabolism ; Glucose/metabolism* ; Metabolic Networks and Pathways ; Signal Transduction ; Metabolic Reprogramming