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 observe the evolution of intrahepatic macrophage polarization in mice with liver fibrosis induced by iron overload. METHODS: Thirty-two C57BL/6 mice (6-8 weeks) were randomized into control group (n=8) and liver fibrosis model group (n=24) induced by aidly intraperitoneal injection of iron dextran. At the 3rd, 5th, and 7th weeks of modeling, 8 mice in the model group were sacrificed for observing liver fibrosis using Masson, Sirius Red and immunohistochemical staining and detecting serum levels of ALT, AST and the levels of serum iron, ferritin, liver total Fe and ferrous Fe. iNOS⁺/F4/80⁺ cells and CD206⁺/F4/80⁺ cells were detected by double immunofluorescence assay to observe the proportion and distribution of M1 and M2 macrophages. The hepatic expressions of Arg-1, iNOS, IL-6, IL-10, and TNF‑α proteins were detected using Western blotting or ELISA, and the expression of CD206 mRNA was detected using RT-PCR. RESULTS: The mice in the model group showed gradual increase of fibrous tissue hyperplasia in the portal area over time, structural destruction of the hepatic lobules and formation of pseudolobules. With the passage of time during modeling, the rat models showed significantly increased hepatic expressions of α-SMA and COL-1, elevated serum levels of ALT, AST, Fe, ferritin, and increased liver total Fe and ferrous Fe levels. The expressions of M1 polarization markers IL-6, TNF‑α, and iNOS all increased with time and reached their peak levels at the 3rd week; The expressions of M2 polarization markers (IL-10 and Arg-1 proteins and CD206 mRNA) significantly increased in the 3rd week and but decreased in the 5th and 7th weeks. CONCLUSIONS Iron overload promotes M1 polarization of macrophages in mice. Liver fibrosis in the early stage promotes M2 polarization of macrophages but negatively regulate M2 polarization at later stages.
Animals ; Mice ; Mice, Inbred C57BL ; Iron Overload/pathology* ; Macrophages/metabolism* ; Male ; Liver Cirrhosis/etiology* ; Nitric Oxide Synthase Type II/metabolism* ; Interleukin-10/metabolism* ; Liver/pathology* ; Interleukin-6/metabolism* ; Mannose Receptor ; Tumor Necrosis Factor-alpha/metabolism* ; Mannose-Binding Lectins/metabolism* ; Arginase

Guided by molecular networking, nine novel curvularin derivatives (1-9) and 16 known analogs (10-25) were isolated from the hydrothermal vent sediment fungus Penicillium sp. HL-50. Notably, compounds 5-7 represented a hybrid of curvularin and purine. The structures and absolute configurations of compounds 1-9 were elucidated via nuclear magnetic resonance (NMR) spectroscopy, X-ray diffraction, electronic circular dichroism (ECD) calculations, ¹³C NMR calculation, modified Mosher's method, and chemical derivatization. Investigation of anti-inflammatory activities revealed that compounds 7-9, 11, 12, 14, 15, and 18 exhibited significant suppressive effects against lipopolysaccharide (LPS)-induced nitric oxide (NO) production in murine macrophage RAW264.7 cells, with IC₅₀ values ranging from 0.44 to 4.40 μmol·L^-1. Furthermore, these bioactive compounds were found to suppress the expression of inflammation-related proteins, including inducible NO synthase (iNOS), cyclooxygenase-2 (COX-2), NLR family pyrin domain-containing protein 3 (NLRP3), and nuclear factor kappa-B (NF-κB). Additional studies demonstrated that the novel compound 7 possessed potent anti-inflammatory activity by inhibiting the transcription of inflammation-related genes, downregulating the expression of inflammation-related proteins, and inhibiting the release of inflammatory cytokines, indicating its potential application in the treatment of inflammatory diseases.
Penicillium/chemistry* ; Mice ; Animals ; Anti-Inflammatory Agents/isolation & purification* ; RAW 264.7 Cells ; Nitric Oxide/metabolism* ; Hydrothermal Vents/microbiology* ; Macrophages/immunology* ; Molecular Structure ; Nitric Oxide Synthase Type II/immunology* ; Cyclooxygenase 2/immunology* ; Geologic Sediments/microbiology* ; NF-kappa B/immunology* ; NLR Family, Pyrin Domain-Containing 3 Protein/immunology*

Microglia, the resident immune cells in the central nervous system (CNS), rapidly transition from a resting to an active state in the acute phase of ischemic brain injury. This active state mediates a pro-inflammatory response that can exacerbate the injury. Targeting the pro-inflammatory response of microglia in the semi-dark band during this acute phase may effectively reduce brain injury. Shionone (SH), an active ingredient extracted from the dried roots and rhizomes of the genus Aster (Asteraceae), has been reported to regulate the inflammatory response of macrophages in sepsis-induced acute lung injury. However, its function in post-stroke neuroinflammation, particularly microglia-mediated neuroinflammation, remains uninvestigated. This study found that SH significantly inhibited lipopolysaccharide (LPS)-induced elevation of inflammatory cytokines, including interleukin-1β (IL-1β), tumor necrosis factor-α (TNF-α), and inducible nitric oxide synthase (iNOS), in microglia in vitro. Furthermore, the results demonstrated that SH alleviated infarct volume and improved behavioral performance in middle cerebral artery occlusion (MCAO) mice, which may be attributed to the inhibition of the microglial inflammatory response induced by SH treatment. Mechanistically, SH potently inhibited the phosphorylation of serine-threonine protein kinase B (AKT), mammalian target of rapamycin (mTOR), and signal transducer and activator of transcription 3 (STAT3). These findings suggest that SH may be a potential therapeutic agent for relieving ischemic stroke (IS) by alleviating microglia-associated neuroinflammation.
Animals ; Microglia/immunology* ; Mice ; Male ; Mice, Inbred C57BL ; Brain Ischemia/immunology* ; Neuroinflammatory Diseases/drug therapy* ; Neuroprotective Agents/administration & dosage* ; Interleukin-1beta/genetics* ; STAT3 Transcription Factor/genetics* ; TOR Serine-Threonine Kinases/genetics* ; Tumor Necrosis Factor-alpha/genetics* ; Proto-Oncogene Proteins c-akt/immunology* ; Nitric Oxide Synthase Type II/genetics* ; Lipopolysaccharides

Five meroterpenoids, rhodonoids K-M (1-2), daurichromene E (3), and grifolins A-B (4-5), together with seven known compounds (6-12), were isolated from Rhododendron anthopogonoides. The chemical structures of these compounds were elucidated through comprehensive analysis of high-resolution electrospray ionization mass spectrometry (HR-ESI-MS), ultraviolet (UV), infrared spectroscopy (IR), and nuclear magnetic resonance (NMR) data. Their absolute configurations were determined by comparing experimental electronic circular dichroism (ECD) spectra with computed values. Notably, compounds 1 and 3 demonstrated significant inhibitory effects on lipopolysaccharide (LPS)-induced inflammation in RAW264.7 cells. These compounds markedly suppressed the mRNA expressions of inflammatory factors, including interleukin (IL)-1β, IL-6, and tumor necrosis factor-α (TNF-α) while also down-regulating the protein expressions of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2).
Mice ; Rhododendron/chemistry* ; Animals ; Anti-Inflammatory Agents/isolation & purification* ; RAW 264.7 Cells ; Terpenes/isolation & purification* ; Molecular Structure ; Tumor Necrosis Factor-alpha/immunology* ; Cyclooxygenase 2/immunology* ; Nitric Oxide Synthase Type II/immunology* ; Macrophages/immunology* ; Interleukin-6/immunology* ; Lipopolysaccharides ; Interleukin-1beta/immunology*

Lirispirolides A-L (1-12), twelve novel sesquiterpene-monoterpene heterodimers featuring distinctive carbon skeletons, were isolated from the branches and leaves of Chinese tulip tree [Liriodendron chinense (L. chinense)], a rare medicinal and ornamental plant endemic to China. The structural elucidation was accomplished through comprehensive spectroscopic analyses, quantum-chemical calculations, and X-ray crystallography. These heterodimers exhibit a characteristic 2-oxaspiro[4.5]decan-1-one structural motif, biosynthetically formed through intermolecular [4 + 2]-cycloaddition between a germacrane-type sesquiterpene and an ocimene-type monoterpene. The majority of the isolated compounds demonstrated significant anti-neuroinflammatory effects in lipopolysaccharide (LPS)-induced BV-2 microglial cells by reducing the production of pro-inflammatory mediators, specifically tumor necrosis factor-α (TNF-α) and nitric oxide (NO). Further investigation revealed that the lirispirolides' inhibition of NO release correlated with decreased messenger ribonucleic acid (mRNA) expression of inducible NO synthase (iNOS).
Sesquiterpenes/isolation & purification* ; Anti-Inflammatory Agents/isolation & purification* ; Animals ; Mice ; Tumor Necrosis Factor-alpha/genetics* ; Nitric Oxide/immunology* ; Microglia/immunology* ; Molecular Structure ; Liriodendron/chemistry* ; Monoterpenes/isolation & purification* ; Plants, Medicinal/chemistry* ; Cell Line ; Lipopolysaccharides ; Nitric Oxide Synthase Type II/immunology* ; Plant Extracts/pharmacology* ; China

In continuation of research aimed at identifying anti-inflammatory agents from natural sesquiterpenoids, an activity-guided fractionation approach utilizing lipopolysaccharide (LPS)-mediated RAW264.7 cells was employed to investigate chemical constituents from Inula Britannica (I. britannica). Seven novel sesquiterpenoid dimers inulabritanoids A-G (1-7) and two novel sesquiterpenoid monomers inulabritanoids H (8) and I (9) were isolated from I. britannica together with eighteen known compounds (10-27). The structural elucidation was accomplished through comprehensive analysis of 1D and 2D nuclear magnetic resonance (NMR), high-resolution mass spectrometry (HR-MS), and electronic circular dichroism (ECD) spectra, complemented by quantum chemical calculations. Compounds 1, 2, 12, 16, 19, and 26 demonstrated inhibitory effects on NO production, with IC₅₀ values of 3.65, 5.48, 3.29, 6.91, 3.12, and 5.67 μmol·L^-1, respectively. Mechanistic studies revealed that compound 1 inhibited IκB kinase β (IKKβ) phosphorylation, thereby blocking nuclear factor κB (NF-κB) nuclear translocation, and activated the kelch-like ECH-associated protein 1 (Keap1)/nuclear factor erythroid 2-related factor 2 (Nrf2) signal pathway, leading to decreased expression of NADPH oxidase 2 (NOX-2), inducible nitric oxide synthase (iNOS), tumor necrosis factor α (TNF-α), interleukin-6 (IL-6), monocyte chemotactic protein-1 (MCP-1), IL-1β, and IL-1α and increased expression of NAD(P)H: quinone oxidoreductase 1 (NQO-1) and heme oxygenase-1 (HO-1), thus exhibiting anti-inflammatory effects in vitro. These results indicate that dimeric sesquiterpenoids may serve as promising candidates for anti-inflammatory drug development.
Mice ; Animals ; Sesquiterpenes/isolation & purification* ; Anti-Inflammatory Agents/isolation & purification* ; Inula/chemistry* ; RAW 264.7 Cells ; Nitric Oxide ; Molecular Structure ; NF-kappa B/immunology* ; NF-E2-Related Factor 2/immunology* ; Macrophages/immunology* ; Nitric Oxide Synthase Type II/immunology* ; Plant Extracts/pharmacology* ; Lipopolysaccharides ; Tumor Necrosis Factor-alpha/immunology* ; I-kappa B Kinase/genetics*

The anti-inflammatory phytochemical investigation of the leaves of Illicium dunnianum (I. dunnianum) resulted in the isolation of five pairs of new lignans (1-5), and 7 known analogs (6-12). The separation of enantiomer mixtures 1-5 to 1a/1b-5a/5b was achieved using a chiral column with acetonitrile-water mixtures as eluents. The planar structures of 1-2 were previously undescribed, and the chiral separation and absolute configurations of 3-5 were reported for the first time. Their structures were determined through comprehensive spectroscopic data analysis [nuclear magnetic resonance (NMR), high-resolution electrospray ionization mass (HR-ESI-MS), infrared (IR), and ultraviolet (UV)] and quantum chemistry calculations (ECD). The new isolates were evaluated by measuring their inhibitory effect on NO in lipopolysaccharide (LPS)-stimulated BV-2 cells. Compounds 1a, 3a, 3b, and 5a demonstrated partial inhibition of NO production in a concentration-dependent manner. Western blot and real-time polymerase chain reaction (PCR) assays revealed that 1a down-regulated the messenger ribonucleic acid (mRNA) levels of tumor necrosis factor α (TNF-α), interleukin-6 (IL-6), COX-2, and iNOS and the protein expressions of COX-2 and iNOS. This research provides guidance and evidence for the further development and utilization of I. dunnianum.
Lignans/isolation & purification* ; Plant Leaves/chemistry* ; Anti-Inflammatory Agents/isolation & purification* ; Mice ; Animals ; Molecular Structure ; Plant Extracts/pharmacology* ; Illicium/chemistry* ; Cyclooxygenase 2/immunology* ; Interleukin-6/immunology* ; Nitric Oxide/metabolism* ; Cell Line ; Tumor Necrosis Factor-alpha/immunology* ; Nitric Oxide Synthase Type II/immunology* ; Lipopolysaccharides

Based on the α7 nicotinic acetylcholine receptor(α7nAChR), this study examined how tetrahydropalmatine(THP) affected BV2 microglia exposed to lipopolysaccharide(LPS), aiming to clarify the possible mechanism underlying the anti-depression effect of THP from the perspectives of preventing inflammation and regulating polarization. First, after molecular docking and determination of the content of Corydalis saxicola Bunting total alkaloids, THP was initially identified as a possible anti-depression component. The BV2 microglia model of inflammation was established with LPS. BV2 microglia were allocated into a normal group, a model group, low-and high-dose(20 and 40 μmol·L~(-1), respectively) THP groups, and a THP(20 μmol·L~(-1))+α7nAChR-specific antagonist MLA(1 μmol·L~(-1)) group. The CCK-8 assay was used to screen the safe concentration of THP. A light microscope was used to examine the morphology of the cells. Western blot and immunofluorescence were used to determine the expression of α7nAChR. qRT-PCR was performed to determine the mRNA levels of inducible nitric oxide synthase(iNOS), cluster of differentiation 86(CD86), suppressor of cytokine signaling 3(SOCS3), arginase-1(Arg-1), cluster of differentiation 206(CD206), tumor necrosis factor(TNF)-α, interleukin(IL)-6, and IL-1β. Enzyme-linked immunosorbent assay(ELISA) was employed to measure the levels of TNF-α, IL-6, and IL-1β in the cell supernatant. The experimental results showed that THP at concentrations of 40 μmol·L~(-1) and below had no effect on BV2 microglia. THP improved the morphology of BV2 microglia, significantly up-regulated the protein level of α7nAChR, significantly down-regulated the mRNA levels of iNOS, CD86, SOCS3, TNF-α, IL-6, and IL-1β, significantly up-regulated the mRNA levels of Arg-1 and CD206, and dramatically lowered the levels of TNF-α, IL-6, and IL-1β in the cell supernatant. However, the antagonist MLA abolished the above-mentioned ameliorative effects of THP on LPS-treated BV2 microglia. As demonstrated by the aforementioned findings, THP protected LPS-treated BV2 microglia by regulating the M1/M2 polarization and preventing inflammation, which might be connected to the regulation of α7nAChR on BV2 microglia.
Berberine Alkaloids/chemistry* ; alpha7 Nicotinic Acetylcholine Receptor/chemistry* ; Microglia/metabolism* ; Mice ; Animals ; Cell Line ; Corydalis/chemistry* ; Humans ; Molecular Docking Simulation ; Inflammation/drug therapy* ; Nitric Oxide Synthase Type II/immunology* ; Tumor Necrosis Factor-alpha/immunology*

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