Macrophage Oxidative Stress Research Articles

Targeting ICAM1 to Ameliorate Vaso-Occlusion and Inflammation in Sickle Cell Disease.

Sickle cell disease (SCD) is a hereditary disorder characterized by vaso-occlusion, inflammation, and tissue damage. Intercellular adhesion molecule 1 (ICAM-1) plays a crucial role in the pathophysiology of SCD by promoting the adhesion of sickle cells to the endothelium, contributing to vaso-occlusion and tissue damage. The ICAM-1 gene encodes a glycoprotein that interacts with lymphocyte function-associated antigen 1 (LFA-1) and macrophage 1-antigen (Mac-1) receptors, perpetuating inflammation, and oxidative stress. The NF-κB signaling pathway regulates ICAM-1 expression, which is elevated in patients with SCD, leading to increased endothelial cell activation and damage. Targeting ICAM-1 and its interactions with sickle cells and the endothelium has emerged as a potential therapeutic strategy for managing SCD. This review highlights the complex interplay between ICAM-1, sickle cells, and the endothelium, and discusses the potential of ICAM-1-targeted therapies for mitigating VOC and improving the quality of life for patients with SCD.

PdZn/CoSA‐NC Nanozymes with Highly Efficient SOD/CAT Activities for Treatment of Osteoarthritis via Regulating Immune Microenvironment

AbstractInflammatory infiltration of synovial M1 macrophages, high levels of ROS, and NO exacerbate osteoarthritis (OA) progression. The PdZn/CoSA‐NC nanozymes, which are highly ordered PdZn intermetallic nanoparticles loaded with Co single atom N‐doped carbon‐rich in multi‐level pores, in an attempt to serve as SOD and CAT mimicking nanozymes for OA therapy is designed. The PdZn/CoSA‐NC nanozymes' high electron transfer and dual active site sufficient exposure enhances free radical adsorption and lower reaction energies, accelerating SOD‐like, CAT‐like, and GPx‐like catalyzed reactions, outperforming CoSA‐NC and PdZn/NC alone. Furthermore, PdZn/CoSA‐NC nanozymes exhibit favorable biocompatibility, reduce synovial macrophage oxidative stress in OA, alleviate hypoxia, restore mitochondrial function, regulate energy metabolism, increase antioxidant factors, and reduce inflammatory factors, thus effectively mitigating the progression of OA. Mechanistically, PdZn/CoSA‐NC nanozymes downregulate M1‐type phenotypic markers like IL‐1β by regulating purine metabolism. The PdZn/CoSA‐NC nanozymes offer a novel approach to treating oxidative stress‐related inflammatory diseases.

The glycyl-l-histidyl-l-lysine-Cu2+ tripeptide complex attenuates lung inflammation and fibrosis in silicosis by targeting peroxiredoxin 6

Silicosis is the most common type of pneumoconiosis, having a high incidence in workers chronically exposed to crystalline silica (CS). No specific medication exists for this condition. GHK, a tripeptide naturally occurring in human blood and urine, has antioxidant effects. We aimed to investigate the therapeutic effect of GHK-Cu on silicosis and its potential underlying molecular mechanism. An experimental silicosis mouse model was established to observe the effects of GHK-Cu on lung inflammation and fibrosis. Moreover, the effects of GHK-Cu on the alveolar macrophages (AM) were examined using the RAW264.7 cell line. Its molecular target, peroxiredoxin 6 (PRDX6), has been identified, and GHK-Cu can bind to PRDX6, thus attenuating lung inflammation and fibrosis in silicosis mice without significant systemic toxicity. These effects were partly related to the inhibition of the CS-induced oxidative stress in AM induced by GHK-Cu. Thus, our results suggest that GHK-Cu acts as a potential drug by attenuating alveolar macrophage oxidative stress. This, in turn, attenuates the progression of pulmonary inflammation and fibrosis, which provides a reference for the treatment of silicosis.

Sulforaphane Inhibits Oxidative Stress and May Exert Anti-Pyroptotic Effects by Modulating NRF2/NLRP3 Signaling Pathway in Mycobacterium tuberculosis-Infected Macrophages.

Sulforaphane (SFN) is a natural isothiocyanate derived from cruciferous vegetables such as broccoli, Brussels sprouts, and cabbage. SFN plays a crucial role in maintaining redox homeostasis by interacting with the active cysteine residues of Keap1, leading to the dissociation and activation of NRF2 in various diseases. In this study, our objective was to investigate the impact of SFN on oxidative stress and pyroptosis in Mycobacterium tuberculosis (Mtb)-infected macrophages. Our findings demonstrated that Mtb infection significantly increased the production of iNOS and ROS, indicating the induction of oxidative stress in macrophages. However, treatment with SFN effectively suppressed the expression of iNOS and COX-2 and reduced MDA and ROS levels, while enhancing GSH content as well as upregulating NRF2, HO-1, and NQO-1 expression in Mtb-infected RAW264.7 macrophages and primary peritoneal macrophages from WT mice. These results suggest that SFN mitigates oxidative stress by activating the NRF2 signaling pathway in Mtb-infected macrophages. Furthermore, excessive ROS production activates the NLRP3 signaling pathway, thereby promoting pyroptosis onset. Further investigations revealed that SFN effectively suppressed the expression of NLRP3, Caspase-1, and GSDMD, IL-1β, and IL-18 levels, as well as the production of LDH, suggesting that it may exhibit anti-pyroptotic effects through activation of the NRF2 signaling pathway and reductions in ROS production during Mtb infection. Moreover, we observed that SFN also inhibited the expression of NLRP3, ASC, Caspase1, and IL-1β along with LDH production in Mtb-infected primary peritoneal macrophages from NFR2-/- mice. This indicates that SFN can directly suppress NLRP3 activation and possibly inhibit pyroptosis initiation in an NRF2-independent manner. In summary, our findings demonstrate that SFN exerts its inhibitory effects on oxidative stress by activating the NRF2 signaling pathway in Mtb-infected macrophages, while it may simultaneously exert anti-pyroptotic properties through both NRF2-dependent and independent mechanisms targeting the NLRP3 signaling pathway.

Inhibition of OGG1 ameliorates pulmonary fibrosis via preventing M2 macrophage polarization and activating PINK1-mediated mitophagy

Background8-Oxoguanine DNA glycosylase (OGG1), a well-known DNA repair enzyme, has been demonstrated to promote lung fibrosis, while the specific regulatory mechanism of OGG1 during pulmonary fibrosis remains unclarified.MethodsA bleomycin (BLM)-induced mouse pulmonary fibrosis model was established, and TH5487 (the small molecule OGG1 inhibitor) and Mitochondrial division inhibitor 1 (Mdivi-1) were used for administration. Histopathological injury of the lung tissues was assessed. The profibrotic factors and oxidative stress-related factors were examined using the commercial kits. Western blot was used to examine protein expression and immunofluorescence analysis was conducted to assess macrophages polarization and autophagy. The conditional medium from M2 macrophages was harvested and added to HFL-1 cells for culture to simulate the immune microenvironment around fibroblasts during pulmonary fibrosis. Subsequently, the loss- and gain-of function experiments were conducted to further confirm the molecular mechanism of OGG1/PINK1.ResultsIn BLM-induced pulmonary fibrosis, OGG1 was upregulated while PINK1/Parkin was downregulated. Macrophages were activated and polarized to M2 phenotype. TH5487 administration effectively mitigated pulmonary fibrosis, M2 macrophage polarization, oxidative stress and mitochondrial dysfunction while promoted PINK1/Parkin-mediated mitophagy in lung tissues of BLM-induced mice, which was partly hindered by Mdivi-1. PINK1 overexpression restricted M2 macrophages-induced oxidative stress, mitochondrial dysfunction and mitophagy inactivation in lung fibroblast cells, and OGG1 knockdown could promote PINK1/Parkin expression and alleviate M2 macrophages-induced mitochondrial dysfunction in HFL-1 cells.ConclusionOGG1 inhibition protects against pulmonary fibrosis, which is partly via activating PINK1/Parkin-mediated mitophagy and retarding M2 macrophage polarization, providing a therapeutic target for pulmonary fibrosis.

Activating Macrophage Continual Efferocytosis via Microenvironment Biomimetic Short Fibers for Reversing Inflammation in Bone Repair.

Efferocytosis-mediated inflammatory reversal plays a crucial role in bone repairing process. However, in refractory bone defects, the macrophage continual efferocytosis may be suppressed due to the disrupted microenvironment homeostasis, particularly the loss of apoptotic signals and overactivation of intracellular oxidative stress. In this study, a polydopamine-coated short fiber matrix containing biomimetic "apoptotic signals" to reconstruct the microenvironment and reactivate macrophage continual efferocytosis for inflammatory reversal and bone defect repair is presented. The "apoptotic signals" (AM/CeO2) are prepared using CeO2 nanoenzymes with apoptotic neutrophil membrane coating for macrophage recognition and oxidative stress regulation. Additionally, a short fiber "biomimetic matrix" is utilized for loading AM/CeO2 signals via abundant adhesion sites involving π-π stacking and hydrogen bonding interactions. Ultimately, the implantable apoptosis-mimetic nanoenzyme/short-fiber matrixes (PFS@AM/CeO2), integrating apoptotic signals and biomimetic matrixes, are constructed to facilitate inflammatory reversal and reestablish the pro-efferocytosis microenvironment. In vitro and in vivo data indicate that the microenvironment biomimetic short fibers can activate macrophage continual efferocytosis, leading to the suppression of overactivated inflammation. The enhanced repair of rat femoral defect further demonstrates the osteogenic potential of the pro-efferocytosis strategy. It is believed that the regulation of macrophage efferocytosis through microenvironment biomimetic materials can provide a new perspective for tissue repair.

Inflammatory corpuscle AIM2 facilitates macrophage foam cell formation by inhibiting cholesterol efflux protein ABCA1

The inflammatory corpuscle recombinant absents in melanoma 2 (AIM2) and cholesterol efflux protein ATP binding cassette transporter A1(ABCA1) have been reported to play opposing roles in atherosclerosis (AS) plaques. However, the relationship between AIM2 and ABCA1 remains unclear. In this study, we explored the potential connection between AIM2 and ABCA1 in the modulation of AS by bioinformatic analysis combined with in vitro experiments. The GEO database was used to obtain AS transcriptional profiling data; screen differentially expressed genes (DEGs) and construct a weighted gene co-expression network analysis (WGCNA) to obtain AS-related modules. Phorbol myristate acetate (PMA) was used to induce macrophage modelling in THP-1 cells, and ox-LDL was used to induce macrophage foam cell formation. The experiment was divided into Negative Control (NC) group, Model Control (MC) group, AIM2 overexpression + ox-LDL (OE AIM2 + ox-LDL) group, and AIM2 short hairpin RNA + ox-LDL (sh AIM2 + ox-LDL) group. The intracellular cholesterol efflux rate was detected by scintillation counting; high-performance liquid chromatography (HPLC) was used to detect intracellular cholesterol levels; apoptosis levels were detected by TUNEL kit; levels of inflammatory markers (IL-1β, IL-18, ROS, and GSH) were detected by ELISA kits; and levels of AIM2 and ABCA1 proteins were detected by Western blot. Bioinformatic analysis revealed that the turquoise module correlated most strongly with AS, and AIM2 and ABCA1 were co-expressed in the turquoise module with a trend towards negative correlation. In vitro experiments demonstrated that AIM2 inhibited macrophage cholesterol efflux, resulting in increased intracellular cholesterol levels and foam cell formation. Moreover, AIM2 had a synergistic effect with ox-LDL, exacerbating macrophage oxidative stress and inflammatory response. Silencing AIM2 ameliorated the above conditions. Furthermore, the protein expression levels of AIM2 and ABCA1 were consistent with the bioinformatic analysis, showing a negative correlation. AIM2 inhibits ABCA1 expression, causing abnormal cholesterol metabolism in macrophages and ultimately leading to foam cell formation. Inhibiting AIM2 may reverse this process. Overall, our study suggests that AIM2 is a reliable anti-inflammatory therapeutic target for AS. Inhibiting AIM2 expression may reduce foam cell formation and, consequently, inhibit the progression of AS plaques.

Erythromycin regulates peroxisome proliferator-activated receptor γ to ameliorate cigarette smoke-induced oxidative stress in macrophages.

Chronic obstructive pulmonary disease (COPD) is significantly influenced by oxidative stress. Recent studies have elucidated the anti-oxidative stress properties of peroxisome proliferator-activated receptors γ (PPARγ), augmenting its known anti-inflammatory effects. The exact influence of PPARγ on oxidative stress in COPD remains elusive. This study aimed to investigate the potential mechanism by which PPARγ counteracts the oxidative stress instigated by cigarette smoke in macrophages. Macrophages were cultured and exposed to 1% cigarette smoke extract (CSE), 1 µg/mL erythromycin (EM), and 10 µmol/mL GW9662 (a PPARγ antagonist). Reactive oxygen species (ROS) in macrophages was identified using fluorescent microscopy. PPARγ expression was ascertained through reverse transcription-polymerase chain reaction (RT-PCR) and Western blot techniques. The superoxide dismutase (SOD) in macrophage supernatant was measured by enzyme linked immunosorbent assay (ELISA), as was malondialdehyde (MDA). Our results shown that cigarette smoke stimulated macrophages to increase ROS release, decrease the expression of PPARγ, increase the expression of MDA and decrease the expression of SOD. After PPARγ inhibitor acted on macrophages stimulated by cigarette smoke, the expression of MDA was inhibited and the content of SOD increased. When EM was used to treat macrophages stimulated by cigarette smoke, the expression of ROS decreased, the expression of PPARγ increased, the expression of MDA decreased and the expression of SOD increased. This study suggests that PPARγ plays an anti-oxidative role by inhibiting the expression of MDA and promoting the expression of SOD. Cigarette smoke induces oxidative stress by inhibiting PPARγ pathway. EM inhibits oxidative stress by activating PPARγ pathway.

Tpl2-/- macrophages exhibit impaired mitochondrial respiration due to type I interferon signaling in response to LPS stimulation.

Abstract Macrophages are essential to the innate immune system and their dysfunction has been implicated in many diseases, including autoimmunity, obesity, and cancer. Activated macrophages can alter their oxidative phosphorylation, metabolite production, and reactive oxygen species generation to elicit their diverse functions. Tumor progression locus 2 (Tpl2, MAP3K8, or COT) is a serine-threonine kinase involved in macrophage activation and function. In TLR-stimulated macrophages, TPL2 ablation induces high type I interferon (IFN) production. Previous research implicates type I IFNs in metabolic regulation, but their exact mechanism remains unclear. We hypothesize that TPL2 promotes oxidative phosphorylation in LPS-stimulated macrophages by suppressing type I IFN signaling. LPS-stimulated Tpl2-/- bone marrow-derived macrophages had decreased oxygen consumption, ATP production, and maximal respiration compared to LPS-stimulated wild type and Tpl2-/-IFNAR-/- macrophages. LPS-stimulated Tpl2-/- macrophages had reduced antioxidant gene expression compared to wild type macrophages, including SOD2, HMOX-1, and PRDX5. Disrupted IFN signaling in IFNAR-/- and Tpl2-/-IFNAR-/- macrophages significantly increased antioxidant gene expression, suggesting the absence of IFN signaling mitigates macrophage oxidative stress. These data indicate that Tpl2-/- macrophages are metabolically defective and type I IFNs contribute to the underlying dysfunction.

Investigating the role of itaconate in macrophage activation and oxidative stress injury in sepsis-associated acute kidney injury.

Sepsis may be linked to oxidative stress and can be controlled by itaconate, an activator of the nuclear factor erythroid 2-related factor 2 (Nrf2) pathway. Nevertheless, the itaconate impact on sepsis-associated acute kidney injury (SA-AKI) has yet to be definitively established. We employed SA-AKI mouse model through a cecal ligation and puncture (CLP) procedure for the in vivo investigation of the potential nephroprotective effect of itaconate in this study. A plasmid was transfected into RAW264.7 cells to examine the Nrf2 pathway function after itaconate administration. Finally, the immune-responsive gene 1-knockout (IRG1-/-) mice were used to study the itaconate impacts on oxidative stress-induced SA-AKI. We have shown that 4-octyl itaconate (OI) significantly reduced CD11b-positive macrophage aggregation and activated the Nrf2 pathway in the bone marrow-derived macrophages (BMDM). The impacts of Nrf2 inhibitor ML385 on the anti-inflammatory and antioxidant properties of itaconate were found to be partial. OI inhibited lipopolysaccharide-induced oxidative stress injury in RAW264.7 macrophages and activated Nrf2 in the nucleus to hinder the expression of nuclear factor kappa B p65, thereby suppressing oxidative stress injury in the macrophages. Additionally, the introduction of the transfected plasmid resulted in a partial inhibition of the anti-inflammatory impact of itaconate. The kidney injury caused by sepsis exhibited greater severity in the IRG1-/- mice than in the wild type mice. Exogenous OI partially attenuated the kidney injury induced by sepsis in the IRG1-/- mice and suppressed the oxidative stress injury in macrophages. This investigation offers new proof to support the itaconate function in the development and progression of SA-AKI and shows a new possible therapeutic agent for the SA-AKI treatment.

Anticolorectal Cancer Activity of Bilobalide in Patient-Derived Colorectal Cancer Organoids and AOM/DSS Mouse Model

Bilobalide has shown strong anti-inflammatory activity. Colorectal cancer (CRC) is closely associated with inflammation. However, no studies have reported on the use of bilobalide for treating CRC. This study aims to evaluate the effect of bilobalide on CRC prevention. Enzyme-linked immunosorbent assay (ELISA), quantitative real-time polymerase chain reaction (RT-qPCR), Western blotting, and immunofluorescence showed that bilobalide significantly inhibits the M2 polarization of macrophages dependent on phorbol 12-myristate 13-acetate (PMA) and interleukin-4 (IL-4). Analysis of signaling pathways showed that the phosphorylation of extracellular signal-regulated kinase (ERK), c-Jun N-terminal kinase (JNK), and signal transducer and activator of transcription 3 (STAT3) was regulated. In particular, human CRC organoids were established. Western blotting, terminal deoxynucleotidyl transferase biotin-dUTP nick end labeling (TUNEL), and analysis of cell viability and morphology further supported the hypothesis that the anti-CRC effects of bilobalide could be explained by its ability to suppress M2 macrophage polarization and promote M1 transformation. C57BL/6 mice treated with azoxymethane (AOM)/dextran sodium sulfate (DSS) were divided into three groups, i.e., control, AOM/DSS, low (2.5 mg/kg), and high (5 mg/kg). High-dose bilobalide markedly inhibited the progression of CRC, as evidenced by the increased body weight, decrease in disease activity index (DAI) death rate, and alleviation of colon length reduction and tumorigenesis. According to the in vivo results, reduced levels of inflammatory cytokines in the serum included tumor necrosis factor (TNF-α), IL-6, IL-1β, and IL-10. Bilobalide reduced oxidative stress indices, lipid peroxide (LPO), and malondialdehyde (MDA) and increased reduced glutathione (GSH). In addition, the expression of proliferating cell nuclear antigen (PCNA), Ki67, cellular Myc (c-Myc), and CD206 was downregulated in the drug-treated groups, as confirmed by the immunohistochemical staining. Collectively, these results indicated that bilobalide administration improve experimental CRC by inhibiting M2 macrophage polarization and oxidative stress. Thus, bilobalide may prevent CRC and serve as a potential therapeutic target for CRC.

Iguratimod, an allosteric inhibitor of macrophage migration inhibitory factor (MIF), prevents mortality and oxidative stress in a murine model of acetaminophen overdose

BackgroundMacrophage migration inhibitory factor (MIF) is a pleiotropic cytokine that has been implicated in multiple inflammatory and non-inflammatory diseases, including liver injury induced by acetaminophen (APAP) overdose. Multiple small molecule inhibitors of MIF have been described, including the clinically available anti-rheumatic drug T-614 (iguratimod); however, this drug’s mode of inhibition has not been fully investigated.MethodsWe conducted in vitro testing including kinetic analysis and protein crystallography to elucidate the interactions between MIF and T-614. We also performed in vivo experiments testing the efficacy of T-614 in a murine model of acetaminophen toxicity. We analyzed survival in lethal APAP overdose with and without T-614 and using two different dosing schedules of T-614. We also examined MIF and MIF inhibition effects on hepatic hydrogen peroxide (H2O2) as a surrogate of oxidative stress in non-lethal APAP overdose.ResultsKinetic analysis was consistent with a non-competitive type of inhibition and an inhibition constant (Ki) value of 16 µM. Crystallographic analysis revealed that T-614 binds outside of the tautomerase active site of the MIF trimer, with only the mesyl group of the molecule entering the active site pocket. T-614 improved survival in lethal APAP overdose when given prophylactically, but this protection was not observed when the drug was administered late (6 h after APAP). T-614 also decreased hepatic hydrogen peroxide concentrations during non-lethal APAP overdose in a MIF-dependent fashion.ConclusionsT-614 is an allosteric inhibitor of MIF that prevented death and decreased hepatic hydrogen peroxide concentrations when given prophylactically in a murine model of acetaminophen overdose. Further studies are needed to elucidate the mechanistic role of MIF in APAP toxicity.

Myricanol attenuates sepsis-induced inflammatory responses by nuclear factor erythroid 2-related factor 2 signaling and nuclear factor kappa B/mitogen-activated protein kinase pathway via upregulating Sirtuin 1.

Sepsis, a life-threatening condition characterized by dysregulated immune responses, remains a significant clinical challenge. Myricanol, a natural compound, plays a variety of roles in regulating lipid metabolism, anti-cancer, anti-neurodegeneration, and it could act as an Sirtuin 1 (SIRT1) activator. This study aimed to explore the therapeutic potential and underlying mechanism of myricanol in the lipopolysaccharide (LPS)-induced sepsis model. In vivo studies revealed that myricanol administration significantly improved the survival rate of LPS-treated mice, effectively mitigating LPS-induced inflammatory responses in lung tissue. Furthermore, in vitro studies demonstrated that myricanol treatment inhibited the expression of pro-inflammatory cytokines, attenuated signal pathway activation, and reduced oxidative stress in macrophages. In addition, we demonstrated that myricanol selectively enhances SIRT1 activation in LPS-stimulated macrophages, and all of the protective effect of myricanol were reversed through SIRT1 silencing. Remarkably, the beneficial effects of myricanol against LPS-induced sepsis were abolished in SIRT1 myeloid-specific knockout mice, underpinning the critical role of SIRT1 in mediating myricanol's therapeutic efficacy. In summary, this study provides significant evidence that myricanol acts as a potent SIRT1 activator, targeting inflammatory signal pathways and oxidative stress to suppress excessive inflammatory responses. Our findings highlight the potential of myricanol as a novel therapeutic agent for the treatment of LPS-induced sepsis.

Naringenin Inhibits Acid Sphingomyelinase-Mediated Membrane Raft Clustering to Reduce NADPH Oxidase Activation and Vascular Inflammation.

Macrophage inflammation and oxidative stress promote atherosclerosis progression. Naringenin is a naturally occurring flavonoid with antiatherosclerotic properties. Here, we elucidated the effects of naringenin on monocyte/macrophage endothelial infiltration and vascular inflammation. We found naringenin inhibited oxidized low-density lipoprotein (oxLDL)-induced pro-inflammatory cytokines such as IL-1β, IL-6, and TNF-α toward an M2 macrophage phenotype and inhibited oxLDL-induced TLR4 (Toll-like receptor 4) membrane translocation and downstream NF-κB transcriptional activity. Results from flow cytometric analysis showed that naringenin reduced monocyte/macrophage infiltration in the aorta of high-fat-diet-treated ApoE-deficient mice. The aortic cytokine levels were also inhibited in naringenin-treated mice. Further, we found that naringenin reduced lipid raft clustering and acid sphingomyelinase (ASMase) membrane gathering and inhibited the TLR4 and NADPH oxidase subunit p47phox membrane recruitment, which reduced the inflammatory response. Recombinant ASMase treatment or overexpression of ASMase abolished the naringenin function and activated macrophage and vascular inflammation. We conclude that naringenin inhibits ASMase-mediated lipid raft redox signaling to attenuate macrophage activation and vascular inflammation.

SLC15A3 plays a crucial role in pulmonary fibrosis by regulating macrophage oxidative stress.

Idiopathic pulmonary fibrosis (IPF) is a fatal and irreversible disease with few effective treatments. Alveolar macrophages (AMs) are involved in the development of IPF from the initial stages due to direct exposure to air and respond to external oxidative damage (a major inducement of pulmonary fibrosis). Oxidative stress in AMs plays an indispensable role in promoting fibrosis development. The oligopeptide histidine transporter SLC15A3, mainly expressed on the lysosomal membrane of macrophages and highly expressed in the lung, has proved to be involved in innate immune and antiviral signaling pathways. In this study, we demonstrated that during bleomycin (BLM)- or radiation-induced pulmonary fibrosis, the recruitment of macrophages induced an increase of SLC15A3 in the lung, and the deficiency of SLC15A3 protected mice from pulmonary fibrosis and maintained the homeostasis of the pulmonary microenvironment. Mechanistically, deficiency of SLC15A3 resisted oxidative stress in macrophages, and SLC15A3 interacted with the scaffold protein p62 to regulate its expression and phosphorylation activation, thereby regulating p62-nuclear factor erythroid 2-related factor 2 (NRF2) antioxidant stress pathway protein, which is related to the production of reactive oxygen species (ROS). Overall, our data provided a novel mechanism for targeting SLC15A3 to regulate oxidative stress in macrophages, supporting the therapeutic potential of inhibiting or silencing SLC15A3 for the precautions and treatment of pulmonary fibrosis.

Songorine modulates macrophage polarization and metabolic reprogramming to alleviate inflammation in osteoarthritis.

Osteoarthritis (OA) is a prevalent joint disorder characterized by multifaceted pathogenesis, with macrophage dysregulation playing a critical role in perpetuating inflammation and joint degeneration. This study focuses on Songorine, derived from Aconitum soongaricum Stapf, aiming to unravel its therapeutic mechanisms in OA. Comprehensive analyses, including PCR, Western blot, and immunofluorescence, were employed to evaluate Songorine's impact on the joint microenvironment and macrophage polarization. RNA-seq analysis was conducted to unravel its anti-inflammatory mechanisms in macrophages. Metabolic alterations were explored through extracellular acidification rate monitoring, molecular docking simulations, and PCR assays. Oxygen consumption rate measurements were used to assess mitochondrial oxidative phosphorylation, and Songorine's influence on macrophage oxidative stress was evaluated through gene expression and ROS assays. Songorine effectively shifted macrophage polarization from a pro-inflammatory M1 phenotype to an anti-inflammatory M2 phenotype. Notably, Songorine induced metabolic reprogramming, inhibiting glycolysis and promoting mitochondrial oxidative phosphorylation. This metabolic shift correlated with a reduction in macrophage oxidative stress, highlighting Songorine's potential as an oxidative stress inhibitor. In an in vivo rat model of OA, Songorine exhibited protective effects against cartilage damage and synovial inflammation, emphasizing its therapeutic potential. This comprehensive study elucidates Songorine's multifaceted impact on macrophage modulation, metabolic reprogramming, and the inflammatory microenvironment, providing a theoretical foundation for its therapeutic potential in OA.

Examining the function of macrophage oxidative stress response and immune system in glioblastoma multiforme through analysis of single-cell transcriptomics.

Glioblastoma (GBM), a prevalent malignant neoplasm within the neuro-oncological domain, has been a subject of considerable scrutiny. Macrophages, serving as the principal immunological constituents, profoundly infiltrate the microenvironment of GBM. However, investigations elucidating the intricate immunological mechanisms governing macrophage involvement in GBM at the single-cell level remain notably limited. We conducted a comprehensive investigation employing single-cell analysis, aiming to redefine the intricate cellular landscape within both the core and peripheral regions of GBM tumors. Our analytical focus extended to the profound study of macrophages, elucidating their roles within the context of oxidative stress, intercellular information exchange, and cellular trajectories concerning GBM and its assorted subpopulations. We pursued the identification of GBM prognostic genes intricately associated with macrophages. Utilizing experimental research to investigate the relevance of MANBA in the context of GBM. Our investigations have illuminated the central role of macrophages in the intricate interplay among various subpopulations within the GBM microenvironment. Notably, we observed a pronounced intensity of oxidative stress responses within macrophages when compared to their GBM counterparts in other subpopulations. Moreover, macrophages orchestrated intricate cellular communication networks, facilitated by the SPP1-CD44 axis, both internally and with neighboring subpopulations. These findings collectively suggest the potential for macrophage polarization from an M1 to an M2 phenotype, contributing to immune suppression within the tumor microenvironment. Furthermore, our exploration unearthed GBM prognostic genes closely associated with macrophages, most notably MANBA and TCF12. Remarkably, MANBA appears to participate in the modulation of neuroimmune functionality by exerting inhibitory effects on M1-polarized macrophages, thereby fostering tumor progression. To bolster these assertions, experimental validations unequivocally affirmed the promotional impact of MANBA on GBM, elucidated through its capacity to curb cell proliferation, invasiveness, and metastatic potential. These revelations represent a pivotal step towards unraveling the intricate immunological mechanisms governing the interactions between macrophages and diverse subpopulations within the GBM milieu. Furthermore, they lay the foundation for the development of an innovative GBM prognostic model, with MANBA at its epicenter, and underscore the potential for novel immunotherapeutic targets in the ongoing pursuit of enhanced treatment modalities for this formidable malignancy.

Glutamine Protects against Mouse Abdominal Aortic Aneurysm through Modulating VSMC Apoptosis and M1 Macrophage Activation.

Glutamine (Gln), known as the most abundant free amino acid, is widely spread in human body. In this study, we demonstrated the protective effects of glutamine against mouse abdominal aortic aneurysm (AAA) induced by both angiotensin II (AngII) and calcium phosphate (Ca3(PO4)2) in vivo, which was characterized with lower incidence of mouse AAA. Moreover, histomorphological staining visually presented more intact elastic fiber and less collagen deposition in abdominal aortas of mice treated by glutamine. Further, we found glutamine inhibited the excessive production of reactive oxide species (ROS), activity of matrix metalloproteinase (MMP), M1 macrophage activation, and apoptosis of vascular smooth muscle cells (VSMCs) in suprarenal abdominal aortas of mice, what's more, the high expressions of MMP-2 protein, MMP-9 protein, pro-apoptotic proteins, and IL-6 as well as TNF-α in protein and mRNA levels in cells treated by AngII were down-regulated by glutamine. Collectively, these results revealed that glutamine protected against mouse AAA through inhibiting apoptosis of VSMCs, M1 macrophage activation, oxidative stress, and extracellular matrix degradation.

BRD3308 suppresses macrophage oxidative stress and pyroptosis via upregulating acetylation of H3K27 in sepsis-induced acute lung injury

Abstract Background Sepsis-induced acute lung injury (ALI) leads to severe hypoxemia and respiratory failure, contributing to poor prognosis in septic patients. Endotoxin dissemination triggers oxidative stress and the release of inflammatory cytokines in macrophages, initiating diffuse alveolar damage. The role of epigenetic histone modifications in organ injury is increasingly recognized. The present study aimed to investigate the use of a histone modification inhibitor to alleviate sepsis-induced ALI, revealing a new strategy for improving sepsis patient survival. Methods In vivo models of ALI were established through the intraperitoneal injection of lipopolysaccharide and cecal ligation and puncture surgery. Furthermore, the disease process was simulated in vitro by stimulating Tamm-Horsfall protein-1 (THP-1) cells with lipopolysaccharide. Hematoxylin and eosin staining, blood gas analysis and pulmonary function tests were utilized to assess the extent of lung tissue damage. Western blot analysis, real-time polymerase chain reaction, enzyme-linked immunosorbent assay and immunofluorescence were used to measure the levels and distribution of the indicated indicators within cells and tissues. Reactive oxygen species and autophagic flux alterations were detected using specific probes. Results BRD3308, which is a inhibitor of histone deacetylase 3, improved lung tissue damage, inflammatory infiltration and edema in ALI by inhibiting Nod-like receptor protein3-mediated pyroptosis in macrophages. By upregulating autophagy, BRD3308 improved the disruption of redox balance in macrophages and reduced the accumulation of reactive oxygen species. Mechanistically, BRD3308 inhibited histone deacetylase 3 activity by binding to it and altering its conformation. Following histone deacetylase 3 inhibition, acetylation of H3K27 was significantly increased. Moreover, the increase in H3K27Ac led to the upregulation of autophagy-related gene 5, a key component of autophagosomes, thereby activating autophagy. Conclusions BRD3308 inhibits oxidative stress and pyroptosis in macrophages by modulating histone acetylation, thereby preventing sepsis-induced ALI. The present study provides a potential strategy and theoretical basis for the clinical treatment of sepsis-induced ALI.

Targeted modulation and enhancement of macrophages via sonodynamic therapy-driven cupferroptosis-like stress for implant-associated biofilm infections

As the vanguard against implant-associated infections (IAIs), macrophages facilitate the phagocytosis and pro-inflammatory polarization of planktonic and biofilm infections, but indirectly serve as a “Trojan horse” for intracellular bacterial infections. Effective drug delivery and macrophage immunomodulation to eliminate intracellular infections will contribute to the treatment of refractory IAIs and prevention of relapse. Herein, we developed an ultrasound-responsive copper-based nanoparticle targeting macrophages by encapsulating copper in a porphyrin metal-organic framework and surface-grafting D-Mannosamine to synthesize CuTCPP@MOF nanodots@ Mannosamine (CTMM) with macrophage-targeting functionality. Concurrent generation of hydroxyl radicals and singlet oxygen in biofilm microenvironment mediated by ultrasound disrupts the biofilm structure, achieving CTMM overload and interfering with bacterial biofilm growth and metabolism. By regulating macrophage oxidative stress metabolism, CTMM induced a cupferroptosis-like stress, characterized by concurrent cuproptosis and ferroptosis, to eliminate intracellular infections. Transcriptomic analysis verified that the cupferroptosis-like stress based on GPX4 axis modulation further promotes macrophage inflammatory activation. This CTMM+US-mediated bacterial clearance in biofilms and macrophage immunomodulation informs the "Trojan War" strategy to combat IAIs clinically.