Silver-quercetin-loaded honeycomb-like Ti-based interface combats infection-triggered excessive inflammation via specific bactericidal and macrophage reprogramming.

Excessive inflammation caused by bacterial infection is the primary cause of implant failure. Antibiotic treatment often fails to prevent peri-implant infection and may induce unexpected drug resistance. Herein, a non-antibiotic strategy based on the synergy of silver ion release and macrophage reprogramming is proposed for preventing infection and bacteria-induced inflammation suppression by the organic-inorganic hybridization of silver nanoparticle (AgNP) and quercetin (Que) into a polydopamine (PDA)-based coating on the 3D framework of porous titanium (SQPdFT). Once the planktonic bacteria (e.g., Escherichia coli, Staphylococcus aureus) reach the surface of SQPdFT, released Que disrupts the bacterial membrane. Then, AgNP can penetrate the invading bacterium and kill them, which further inhibits the biofilm formation. Simultaneously, released Que can regulate macrophage polarization homeostasis via the peroxisome proliferators-activated receptors gamma (PPARγ)-mediated nuclear factor kappa-B (NF-κB) pathway, thereby terminating excessive inflammatory responses. These advantages facilitate the adhesion and osteogenic differentiation of bone marrow-derived mesenchymal stem cells (BMSCs), concomitantly suppressing osteoclast maturation, and eventually conferring superior mechanical stability to SQPdFT within the medullary cavity. In summary, owing to its excellent antibacterial effect, immune remodeling function, and pro-osteointegration ability, SQPdFT is a promising protective coating for titanium-based implants used in orthopedic replacement surgery.

Diosmetin-7-O-ß-D-glucopyranoside from Pogostemonis Herba alleviated SARS-CoV-2-induced pneumonia by reshaping macrophage polarization and limiting viral replication.

ETHNOPHARMACOLOGICAL RELEVANCE: Viral pneumonia is the leading cause of death after SARS-CoV-2 infection. Despite effective at early stage, long-term treatment with glucocorticoids can lead to a variety of adverse effects and limited benefits. The Chinese traditional herb Pogostemonis Herba is the aerial part of Pogostemon Cablin (Blanco) Benth., which has potent antiviral, antibacterial, anti-inflammatory, and anticancer effects. It was used widely for treating various throat and respiratory diseases, including COVID-19, viral infection, cough, allergic asthma, acute lung injury and lung cancer. AIM OF THE STUDY: To investigate the antiviral and anti-inflammatory effects of chemical compounds from Pogostemonis Herba in SARS-CoV-2-infected hACE2-overexpressing mouse macrophage RAW264.7 cells and hACE2 transgenic mice. MATERIALS AND METHODS: The hACE2-overexpressing RAW264.7 cells were exposed with SARS-CoV-2. The cell viability was detected by CCK8 assay and cell apoptotic rate was by flow cytometric assay. The expressions of macrophage M1 phenotype markers (TNF-α and IL-6) and M2 markers (IL-10 and Arg-1) as well as the viral loads were detected by qPCR. The mice were inoculated intranasally with SARS-CoV-2 omicron variant to induce viral pneumonia. The levels of macrophages, neutrophils, and T cells in the lung tissues of infected mice were analyzed by full spectrum flow cytometry. The expressions of key proteins were detected by Western blot assay. RESULTS: Diosmetin-7-O-ß-D-glucopyranoside (DG) presented the strongest anti-SARS-CoV-2 activity. Intervention with DG at the concentrations of 0.625-2.5 µM not only reduced the viral replication, cell apoptosis, and the productions of inflammatory cytokines (IL-6 and TNF-α) in SARS-CoV-2-infected RAW264.7 cells, but also reversed macrophage polarity from M1 to M2 phenotype. Furthermore, treatment with DG (25-100 mg/kg) alleviated acute lung injury, and reduced macrophage infiltration in SARS-COV-2-infected mice. Mechanistically, DG inhibited SARS-COV-2 gene expression and HK3 translation via targeting YTHDF1, resulting in the inactivation of glycolysis-mediated NF-κB pathway. CONCLUSIONS: DG exerted the potent antiviral and anti-inflammatory activities. It reduced pneumonia in SARS-COV-2-infected mice via inhibiting the viral replication and accelerating M2 macrophage polarization via targeting YTHDF1, indicating its potential for COVID-19 treatment.

Quercetin Promotes the M1-to-M2 Macrophage Phenotypic Switch During Liver Fibrosis Treatment by Modulating the JAK2/STAT3 Signaling Pathway.

OBJECTIVE: To investigate the underlying mechanism by which quercetin (Que) regulates macrophage polarization and its subsequent therapeutic effect on liver fibrosis, an important pathological precondition for hepatocellular carcinoma (HCC). METHODS: In vitro experiments were performed on the RAW264.7 mouse macrophage line. After the induction of M1-type macrophages with LPS, the effects of Que on cell morphology, M1/M2 surface marker expression, cytokine expression, and JAK2/STAT3 expression were analyzed. In vivo, male SD rats were used as a model of CCL4-induced hepatic fibrosis, and the effects of Que on serum aminotransferase levels, the histopathological structure of liver tissues, and macrophage-associated protein expression in liver tissues were analyzed. RESULTS: In vitro experiments revealed that Que can suppress the activation of the JAK2/STAT3 signaling pathway, leading to decreases in the expression of M1 macrophage surface markers and cytokines. Additionally, Que was found to increase the expression of M2 macrophage surface markers and cytokines. In vivo, assays demonstrated that Que significantly ameliorated the development of inflammation and fibrosis in a rat liver fibrosis model. CONCLUSION: Que can inhibit hepatic fibrosis by promoting M1 to M2 macrophage polarization, which could be associated with its ability to suppress the JAK2/STAT3 signaling pathway in macrophages.

Immune-response gene 1 deficiency aggravates inflammation-triggered cardiac dysfunction by inducing M1 macrophage polarization and aggravating Ly6Chigh monocyte recruitment.

The immune response gene 1 (IRG1) and its metabolite itaconate are implicated in modulating inflammation and oxidative stress, with potential relevance to sepsis-induced myocardial dysfunction (SIMD). This study investigates their roles in SIMD using both in vivo and in vitro models. Mice were subjected to lipopolysaccharide (LPS)-induced sepsis, and cardiac function was assessed in IRG1 knockout (IRG1-/-) and wild-type mice. Exogenous 4-octyl itaconate (4-OI) supplementation was also examined for its protective effects. In vitro, bone marrow-derived macrophages and RAW264.7 cells were treated with 4-OI following Nuclear factor, erythroid 2 like 2 (NRF2)-small interfering RNA administration to elucidate the underlying mechanisms. Our results indicate that IRG1 deficiency exacerbates myocardial injury during sepsis, while 4-OI administration preserves cardiac function and reduces inflammation. Mechanistic insights reveal that 4-OI activates the NRF2/HO-1 pathway, promoting macrophage polarization and attenuating inflammation. These findings underscore the protective role of the IRG1/itaconate axis in SIMD and suggest a therapeutic potential for 4-OI in modulating macrophage responses.

Europium-Containing Nanospheres for Treating Ovariectomy-Induced Osteoporosis: Targeted Bone Remodeling and Macrophage Polarization Modulation.

Purpose: Osteoporosis, characterized by reduced bone mass and structural deterioration, poses a significant healthcare challenge. Traditional treatments, while effective in reducing fracture risks, are often limited by side effects. This study introduces a novel nanocomplex, europium (Eu) ions-doped superparamagnetic iron oxide (SPIO) nanocrystals encapsulated in poly(lactic-co-glycolic acid) (PLGA) nanospheres, abbreviated as SPIO:Eu@PLGA nanospheres, as a potential therapeutic agent for osteoporosis by modulating macrophage polarization, enhancing osteoblast differentiation and inhibiting osteoclastogenesis. Methods: SPIO and SPIO:Eu nanocrystals were synthesized through pyrolysis and encapsulated in PLGA using an emulsification method. To evaluate the impact of SPIO:Eu@PLGA nanospheres on macrophage reprogramming and reactive oxygen species (ROS) production, flow cytometry analysis was conducted. Furthermore, an ovariectomized (OVX) rat model was employed to assess the therapeutic efficacy of SPIO:Eu@PLGA nanospheres in preventing the deterioration of osteoporosis. Results: In vitro, SPIO:Eu@PLGA nanospheres significantly attenuated M1 macrophage activation induced by lipopolysaccharides, promoting a shift towards the M2 phenotype. This action is linked to the modulation of ROS and the NF-κB pathway. Unlike free Eu ions, which do not achieve similar results when not incorporated into the SPIO nanocrystals. SPIO:Eu@PLGA nanospheres enhanced osteoblast differentiation and matrix mineralization while inhibiting RANKL-induced osteoclastogenesis. In vivo studies demonstrated that SPIO:Eu@PLGA nanospheres effectively targeted trabecular bone surfaces in OVX rats under magnetic guidance, preserving their structure and repairing trabecular bone loss by modulating macrophage polarization, thus restoring bone remodeling homeostasis. The study underscores the critical role of Eu doping in boosting the anti-osteoporotic effects of SPIO:Eu@PLGA nanospheres, evident at both cellular and tissue levels in vitro and in vivo. Conclusion: The inclusion of Eu into SPIO matrix suggests a novel approach for developing more effective osteoporosis treatments, particularly for conditions induced by OVX. This research provides essential insights into SPIO:Eu@PLGA nanospheres as an innovative osteoporosis treatment, addressing the limitations of conventional therapies through targeted delivery and macrophage polarization modulation.

Harnessing the Power of Sugar-Based Nanoparticles: A Drug-Free Approach to Enhance Immune Checkpoint Inhibition against Glioblastoma and Pancreatic Cancer.

Cancer cells have a high demand for sugars and express diverse carbohydrate receptors, offering opportunities to improve delivery with multivalent glycopolymer materials. However, effectively delivering glycopolymers to tumors while inhibiting cancer cell activity, altering cellular metabolism, and reversing tumor-associated macrophage (TAM) polarization to overcome immunosuppression remains a challenging area of research due to the lack of reagents capable of simultaneously achieving these objectives. Here, the glycopolymer-like condensed nanoparticle (∼60 nm) was developed by a one-pot carbonization reaction with a single precursor, promoting multivalent interactions for the galactose-related receptors of the M2 macrophage (TAM) and thereby regulating the STAT3/NF-κB pathways. The subsequently induced M2-to-M1 transition was increased with the condensed level of glycopolymer-like nanoparticles. We found that the activation of the glycopolymer-like condensed galactose (CG) nanoparticles influenced monocarboxylate transporter 4 (MCT-4) function, which caused inhibited lactate efflux (similar to inhibitor effects) from cancer cells. Upon internalization via galactose-related endocytosis, CG NPs induced cellular reactive oxygen species (ROS), leading to dual functionalities of cancer cell death and M2-to-M1 macrophage polarization, thereby reducing the tumor's acidic microenvironment and immunosuppression. Blocking the nanoparticle-MCT-4 interaction with antibodies reduced their toxicity in glioblastoma (GBM) and affected macrophage polarization. In orthotopic GBM and pancreatic cancer models, the nanoparticles remodeled the tumor microenvironment from "cold" to "hot", enhancing the efficacy of anti-PD-L1/anti-PD-1 therapy by promoting macrophage polarization and activating cytotoxic T lymphocytes (CTLs) and dendritic cells (DCs). These findings suggest that glycopolymer-like nanoparticles hold promise as a galactose-elicited adjuvant for precise immunotherapy, particularly in targeting hard-to-treat cancers.

Combination of lipopolysaccharide and polygalacturonic acid exerts antitumor activity and augments anti-PD-L1 immunotherapy.

Polygalacturonic acid (PGA) restored the alpha-diversity of gut microbiota and promoted T cells infiltration in tumors. Here, we investigated whether oral administration of PGA could improve the anti-cancer effect of lipopolysaccharide-encapsulated PLGA-PEG-PLGA (LPS/PPP) in mice bearing CT26 tumors. Hydrogels with rapid thermogelling properties can achieve localized and controlled release of LPS, thus retaining the anti-cancer effect of LPS and avoiding a robust inflammatory storm. LPS/PPP promoted M1 macrophage polarization, TLR4 expression, and phagocytosis in tumors. The combination of PGA and LPS/PPP (PGA_LPS) notably repressed CT26 tumor growth and the inhibition rate reached 67.6 %. PGA_LPS triggered the recruitment of helper and cytotoxic T cells, IFN-γ level, decreased the proportion of immunosuppressive regulatory T cells. PGA_LPS also restored the beta-diversity of gut microbiota and increased short chain fatty acids abundance (butyric acid, 608.93 % vs. model group, P < 0.01). PGA_LPS followed by αPD-L1 resulted in obvious inhibition of both CT26 and 4T1 tumor growth, promoted cleaved-caspase 3 and Bax expression, T cell responses and the rescue of T cells exhaustion. These results confirmed that PGA_LPS reinforced the anticancer effect of αPD-L1, probably by reshaping the tumor microenvironment and intestinal flora, which sheds light on the combination approach to intensify the effect of immune checkpoint inhibitors.

Biomimetic Nanomodulator Regulates Oxidative and Inflammatory Stresses to Treat Sepsis-Associated Encephalopathy.

Sepsis-associated encephalopathy (SAE) is a devastating complication of sepsis, affecting approximately 70% of patients with sepsis in intensive care units (ICU). Although the pathophysiological mechanisms remain elusive, sepsis is typically accompanied by systemic inflammatory response syndrome (SIRS) and hyper-oxidative conditions. Here, we introduce a biomimetic nanomodulator (mAOI NP) that specifically targets inflammation site and simultaneously regulates oxidative and inflammatory stresses. mAOI NPs are constructed using metal-coordinated polyphenolic antioxidants (tannic acid) and flavonoid quercetin, which are then coated with macrophage membrane to enhance pharmacokinetics and enable SAE targeting. In a cecal ligation and puncture (CLP)-induced severe sepsis model, mAOI NPs effectively mitigate oxidative stress by purging reactive oxygen species, repairing mitochondrial damage and activating the Nrf2/HO-1 signaling pathway; while polarizing M1 macrophages or microglia toward anti-inflammatory M2 subtype. mAOI NPs potently inhibit sepsis progress, prolong overall survival from 25 to 66% and enhance learning and memory capabilities in SAE mice. Further proteomics analysis reveals that mAOI NPs modulate neurodevelopment processes related to learning and memory formation while also exerting anti-inflammatory and antioxidative effects on brain tissue responses associated with SAE pathology. This study offers significant potential for improving patient outcomes and revolutionizing the treatment landscape for this devastating complication of sepsis.

SCG2 Mediates HNSCC Progression With CCL2/TGFß1high M2 Macrophage Infiltration.

OBJECTIVES: This study aims to unravel the mechanisms underlying M2 macrophage polarization in head and neck squamous cell carcinoma (HNSCC), and identify potential therapeutic targets. MATERIALS AND METHODS: We conducted an integrated bioinformatic analysis using HNSCC bulk transcriptomes from TCGA and GEO databases to pinpoint critical factors influencing M2 macrophage polarization and tumor prognosis. The significance of these genes was validated in function analysis, single-cell transcriptome datasets, and in vitro experiments. Their mechanisms in modulating M2 macrophage polarization were further explored by gene knockdown, cell coculture, and other assays for quantification. RESULTS: We identified a novel prognostic signature of five genes associated with M2 macrophage infiltration, in which SCG2 emerged as a pivotal factor in M2 macrophage polarization in HNSCC. High expression of SCG2 in tumor patients correlated with poorer prognoses, and knocking down SCG2 reduced the proliferation and migration of HNSCC cells, disrupting M2 macrophage polarization. Furthermore, interference of SCG2 resulted in a significant decrease in the secretion of pro-tumor cytokines such as CCL2 and TGFß1. CONCLUSIONS: Our findings provide deeper insights into the pathogenesis of HNSCC and offer promising therapeutic targets for HNSCC, especially SCG2, to inhibit M2 macrophage polarization and modulate cytokine secretion.

Bromodomain containing 4 inhibition combats gastric precancerous lesions via modulating macrophage polarization.

OBJECTIVE: Gastric precancerous lesions (GPL), characterized by intestinal metaplasia and dysplasia, marks a pivotal juncture in the transformation from gastritis to gastric cancer. Research on GPL could offer fresh perspectives on preventing cancer occurrence. METHODS: This study employed 1-methyl-3-nitro-1-nitrosoguanidine (MNNG) to establish GPL rat models and knocked BRD4 down in vivo to assess its impact on the lesions and macrophage morphology. Following that, the impacts of BRD4 knockdown on the malignant phenotypes of human gastric epithelial GES-1 cells were determined. Moreover, conditioned medium from macrophage was gathered and used for GES-1 cell culture. The involvement of macrophage polarization in the BRD4 regulatory mechanism in GES-1 cells was assessed. RESULTS: This study elucidated that MNNG induced an increase level of BRD4 in the rat models. BRD4 knockdown reduced lesions based on pathological sections and immunohistochemistry to detect proliferative antigens. Western blotting and immunofluorescence showed that BRD4 knockdown suppressed epithelial-mesenchymal transition and macrophage M2 polarization. In in vitro experiments, BRD4 knockdown inhibited the malignant phenotype of GES-1 cells and the differentiation of THP-1 cells into M2 macrophages, respectively. The conditioned medium from M2 macrophages with BRD4 knockdown was co-incubated with GES-1 cells, which attenuated the malignant phenotypes compared with the medium from M2 macrophages. CONCLUSION: Through in vivo and in vitro experiments, BRD4 upregulation was found to already occur during GPL, affecting macrophage polarization and epithelial cell cancerization. This finding provides an experimental basis for strategies targeting BRD4 inhibition at this critical stage.

LncRNA MEG3 suppresses hepatocellular carcinoma by stimulating macrophage M1 polarization and modulating immune system via inhibiting CSF-1 in vivo/vitro studies.

Hepatocellular carcinoma (HCC) is characterized by a complex tumor microenvironment (TME), and long non-coding RNAs (lncRNAs) MEG3 emerged as regulators of macrophage polarization with a negative relationship with colony-stimulating factor 1 (CSF-1). Few studies are on the interplay among MEG3, CSF-1, T helper cells (Th), and the programmed cell death protein 1 and its ligands (PD-1/PD-Ls) in TME of HCC.MEG3 expression in THP-1 macrophages, monitored polarization, and PD-1/PD-Ls expression were through flow cytometry, WB, and RT-qPCR. In co-cultures, the interaction of MEG3, macrophage, and HCC was assayed by ELISA. The invasive and migratory of HCC were assessed through experiments such as CCK-8, clonogenic assay, wound healing, and Transwell. A xenograft mouse model of HCC was established, administered with MEG3 overexpression (OE) or knockdown (KD) constructs, and monitored tumor growth. In vitro, MEG3 OE induced a robust M1 macrophage phenotype, evidenced by elevated expression of M1 markers and a significant increase in Th1 cytokines, with a concomitant decrease in Th2 cytokines. This was paralleled by reduced CSF-1 and PD-1/PD-Ls expression. In contrast, MEG3 KD promoted an M2 phenotype with increased CSF-1 and PD-1/PD-Ls expression, and an upregulation of Th2 cytokines. MEG3 OE inhibited the growth, invasion, and migration of HCC, while the opposite was observed when MEG3 was downregulated. In vivo, MEG3 OE resulted in significantly reduced tumor growth, with decreased PD-1/PD-Ls expression on macrophages and enhanced Th1 response. Conversely, MEG3 KD promoted tumor growth with increased PD-1/PD-Ls and a Th2-skewed immune response. MEG3 modulates the TME by affecting TAMs through CSF-1, thereby influencing the balance of Th1/Th2 cells and altering the expression of PD-1/PD-L1s. This study demonstrates that targeting MEG3 is an effective therapeutic strategy for HCC.

[Potential pathways for traditional Chinese medicine intervention in diabetic kidney disease: macrophage polarization].

Diabetic kidney disease(DKD) is a prevalent and severe microvascular complication of type 2 diabetes mellitus(T2DM). Chronic microinflammation is an important factor exacerbating renal tissue damage in DKD individuals. Macrophages play a crucial role in immune-inflammatory responses, and they can transiently and reversibly polarize into the pro-inflammatory M1 phenotype and anti-inflammatory M2 phenotype based on microenvironmental differences. The imbalance in M1/M2 macrophage polarization can exacerbate DKD progression by fostering inflammatory cytokine aggregation in the glomeruli and renal interstitium. Therefore, restoring the balance of macrophage is a pivotal avenue to ameliorate the chronic microinflammation state in DKD. Macrophage polarization is a complex and dynamic process. Various information molecules and cytokines involved in the polarization process play important roles in regulating phenotypes during the progression of DKD. They are closely related to various mechanisms such as metabolism, inflammation, fibrosis, and mitochondrial autophagy in DKD. By coordinating the inflammatory responses through polarization, they play a key role in regulating inflammation in metabolic-related diseases. The complex network of pathways involved in macrophage polarization corresponds well with the multi-pathway, multi-target treatment model of traditional Chinese medicine(TCM). Active ingredients and formulas of TCM can intervene in DKD by regulating macrophage polarization. Studies on relieving renal inflammation, repairing renal tissues, and promoting renal function recovery through macrophage polarization modulation are not uncommon. Therefore, based on exis-ting evidence, this study reviews TCM in targeting M1/M2 macrophage polarization balance to improve DKD, aiming to explore the potential of macrophage polarization in regulating DKD, which is expected to provide evidence support for the clinical diagnosis and treatment of DKD with TCM as well as the exploration of its biological mechanisms.

[Traditional Chinese medicine and active ingredients regulate M1/M2 macrophage polarization balance to treat chronic obstructive pulmonary disease: a review].

Chronic obstructive pulmonary disease(COPD) is a progressive lung dysfunction(disease) caused by long-term inhalation of toxic particles, especially smoking. The continued exposure to harmful substances triggers an abnormal inflammatory response, which causes permanent damage to the respiratory system, ultimately leading to irreversible pathological changes. Lung macrophages(LMs) are key innate immune effectors involved in the recognition, phagocytosis, and clearance of pathogens, as well as in the processing of inhaled hazardous particulate matter(e. g., cigarette smoke and particulate matter). LMs are polarized toward the M1 or M2 phenotype in response to the activation of inflammatory mediators to exert pro-/anti-inflammatory effects, respectively, thus being involved in the pulmonary parenchymal damage(emphysema) and repair(airway remodeling) throughout the process of COPD.In addition, they are responsible for phagocytosis and clearance of apoptotic or necrotic tissue cells, which helps to maintain the stability of the microenvironment in the lungs of COPD patients. Modern studies have revealed that macrophage polarization plays a pivotal role in the pathogenesis and development of COPD and is considered a potential target for treating COPD because of its ability to reduce airway inflammation, inhibit tissue remodeling, and combat oxidative stress. In recent years, traditional Chinese medicine(TCM) and its active ingredients have become a hot area in the treatment of COPD by targeting the balance of M1/M2 macrophage polarization. TCM and its active ingredients can intervene in the inflammatory response to promote the repair of the lung tissue in the patients with COPD. This paper reviews the research achievements of TCM and its active ingredients in this field in recent years,aiming to provide a scientific basis and strong support for the precise diagnosis and treatment of COPD.

[Daidzein attenuates high glucose-induced inflammatory injury in macrophages by regulating NLRP3 inflammasome signaling pathway].

This study aims to explore the inhibitory effect of daidzein on macrophage inflammation induced by high glucose via regulating the NOD-like receptor protein 3(NLRP3) inflammasome signaling pathway. The cell counting kit-8(CCK-8) assay was employed to detect the effects of daidzein at different concentrations on the viability of RAW264.7 cells. Western blot was employed to determine the protein level of tumor necrosis factor(TNF)-α in macrophages exposed to different concentrations of glucose for different time periods as well as the expression levels of proteins involved in the polarization and Toll-like receptor 4(TLR4)-myeloid differentiation factor(MyD88)-NLRP3 inflammasome pathway of the macrophages exposed to high glucose. Enzyme-linked immunosorbent assay was employed to measure the levels of TNF-α, interleukin(IL)-18, and IL-1ß secreted by macrophages. The expression level of nuclear factor-kappa B(NF-κB) p65 in macrophages exposed to high glucose was detected by immunofluorescence, and the level of intracellular reactive oxygen species(ROS) was detected by the DCFH-DA fluorescent probe. The mRNA levels of NLRP3, TNF-α, and IL-18 in macrophages were determined by qRT-PCR. The results showed that treatment with 30 mmol·L~(-1) glucose for 48 h was the best condition for the modeling of macrophage injury. Compared with the blank group, the model group showed improved polarization of macrophages, increased secretion of TNF-α, IL-18, and IL-1ß, elevated ROS level, and up-regulated expression of NF-κB p65. In addition, the modeling up-regulated the mRNA levels of NLRP3, TNF-α, and IL-18 and the protein levels of TLR4, MyD88, NLRP3, NF-κB p65, p-NF-κB p65, I-κB, p-I-κB, ASC, pro-caspase-1, pro-IL-1ß, cleaved IL-1ß, and pro-IL-18. Compared with the model group, daidzein(10, 20, and 40 µmol·L~(-1)) lowered the levels of inflammatory cytokines and down-regulated the mRNA levels of NLRP3, TNF-α, and IL-18 as well as the protein levels of TLR4, MyD88, NLRP3, NF-κB p65, p-NF-κB p65, I-κB, p-I-κB, ASC, pro-caspase-1, pro-IL-1ß, cleaved IL-1ß, and pro-IL-18. In addition, daidzein reduced intracellular ROS. According to the available reports and the experimental results, high glucose can induce the polarization of macrophages and promote the secretion of inflammatory cytokines. Daidzein can inhibit the expression of ROS in macrophages by regulating the NLRP3 inflammasome signaling pathway, thereby reducing the inflammation of macrophages exposed to high glucose.

Triptolide-induced acute liver injury and its mechanism with estradiol in regulating macrophage-mediated inflammation and hepatocyte function.

Triptolide (TP), a diterpene from Tripterygium wilfordii, exhibits potent anti-inflammatory, immunomodulatory, and antitumor properties but is limited by severe hepatotoxicity. This study investigates sex differences in TP-induced liver injury and the protective role of estradiol (E2) in modulating macrophage-mediated inflammation and hepatocyte function. An acute liver injury model was established in male and female Balb/c mice using intraperitoneal TP injection. Liver function tests, histological analyses, and immunohistochemical staining were performed. THP-1 macrophage and various liver cell lines were used to study the effects of TP and E2 in vitro. Virtual screening, molecular docking, luciferase assays, and qPCR were employed to identify potential targets and elucidate underlying mechanisms. TP caused more severe liver injury in female mice, evidenced by increased liver indices, aspartate aminotransferase (AST) levels, and extensive hepatocyte damage. TP promoted M1 macrophage polarization, enhancing inflammation, particularly in female mice. E2 mitigated TP-induced inflammatory responses by downregulating pro-inflammatory cytokines and macrophage activation markers. Molecular docking and functional assays identified Nuclear receptor subfamily 1 group I member 2 (NR1I2) as a key target mediating the protective effects of E2. The study highlights significant sex differences in TP-induced hepatotoxicity, with females being more susceptible. E2 exerts protective effects against TP-induced liver injury by modulating immune responses, presenting a potential therapeutic approach to mitigate drug-induced liver injury (DILI). Further research on NR1I2 could lead to targeted therapies for reducing drug-induced liver damage.

Neu1 deficiency and fibrotic lymph node microenvironment lead to imbalance in M1/M2 macrophage polarization.

Macrophages play a pivotal role in tissue homeostasis, pathogen defense, and inflammation resolution. M1 and M2 macrophage phenotypes represent two faces in a spectrum of responses to microenvironmental changes, crucial in both physiological and pathological conditions. Neuraminidase 1 (Neu1), a lysosomal and cell surface sialidase responsible for removing terminal sialic acid residues from glycoconjugates, modulates several macrophage functions, including phagocytosis and Toll-like receptor (TLR) signaling. Current evidence suggests that Neu1 expression influences M1/M2 macrophage phenotype alterations in the context of cardiovascular diseases, indicating a potential role for Neu1 in macrophage polarization. For this reason, we investigated the impact of Neu1 deficiency on macrophage polarization in vitro and in vivo. Using bone marrow-derived macrophages (BMDMs) and peritoneal macrophages from Neu1 knockout (Neu1-/- ) mice and wild-type (WT) littermate controls, we demonstrated that Neu1-deficient macrophages exhibit an aberrant M2-like phenotype, characterized by elevated macrophage mannose receptor 1 (MMR/CD206) expression and reduced responsiveness to M1 stimuli. This M2-like phenotype was also observed in vivo in peritoneal and splenic macrophages. However, lymph node (LN) macrophages from Neu1-/- mice exhibited phenotypic alterations with reduced CD206 expression. Further analysis revealed that peripheral LNs from Neu1-/- mice were highly fibrotic, with overexpression of transforming growth factor-beta 1 (TGF-ß1) and hyperactivated TGF-ß signaling in LN macrophages. Consistently, TGF-ß1 was found to alter M1/M2 macrophage polarization in vitro. Our findings showed that Neu1 deficiency prompts macrophages towards an M2 phenotype and that microenvironmental changes, particularly increased TGF-ß1 in fibrotic tissues such as peripheral LNs in Neu1-/- mice, further influence M1/M2 macrophage polarization, highlighting its sensitivity to the local microenvironment. Therapeutic interventions targeting Neu1 or TGF-ß signaling pathways may offer the potential to regulate macrophage behavior across different diseases.

Anti-inflammatory effects of 1,7-dihydroxy-3,4-dimethoxyxanthone through inhibition of M1-phenotype macrophages via arginine/mitochondrial axis.

It is known that 1,7-dihydroxy-3,4-dimethoxyxanthone (XAN), derived from Securidaca inappendiculata Hassk., exhibits anti-inflammatory and analgesic activities and inhibits M1 polarization of macrophages. However, its ability to alleviate inflammation induced by pro-inflammatory cytokines in THP-1 cells and its anti-inflammatory mechanisms remain unclear. THP-1 cells were treated with phorbol 12-myristate-13-acetate to differentiate and divided into three groups. They were stimulated with lipopolysaccharide (LPS) and interferon-γ (IFN-γ). The toxicity of XAN was assessed using Cell Counting Kit-8, and the expression of various genes and proteins was analyzed using real-time quantitative polymerase chain reaction, flow cytometry, and western blotting. Transmission electron microscopy was used to observe changes in mitochondrial structure. XAN at concentrations ≤ 10 µg/mL did not affect THP-1 cell viability and reduced the mRNA expression of pro-inflammatory factors, including interleukin (IL)-1ß, inducible nitric oxide synthase (iNOS), NOD-like receptor thermal protein domain protein 3 (NLRP3), and tumor necrosis factor-α (TNF-α). XAN also increased the levels of anti-inflammatory factors, including chemokine ligand 22, mannose receptor (CD206), IL-10, peroxisome proliferator-activated receptor-γ, and transglutaminase 2. Additionally, XAN downregulated the expression of inflammation-related proteins iNOS, NLRP3, and IL-1ß; significantly increased the expression of arginase 1, ornithine decarboxylase, and arginine metabolism-related proteins and genes; inhibited mitochondrial damage; and reduced reactive oxygen species (ROS) generation. XAN enhanced the arginine metabolism pathway, prevented mitochondrial damage, reduced ROS levels, and provided an effective defensive response against LPS/IFN-γ-induced inflammation.

Gypenoside LXXV Alleviates Colitis by Reprograming Macrophage Polarization via the Glucocorticoid Receptor Pathway.

An imbalance in the macrophage phenotype is closely related to various inflammatory diseases. Here, we discovered that gypenoside LXXV (GP-75), a type of saponin from Gynostemma pentaphyllum, can reprogram M1-like macrophages into M2-like ones. On a mechanistic level, GP-75 inhibits NF-κB-COX2 signaling by targeting the glucocorticoid receptor (GR). Administration of GP-75, either orally or by intraperitoneal injection, significantly alleviates ulcerative colitis in mice, a pathogenesis associated with macrophage polarization. Clodronate liposomes, which deplete macrophages in mice, as well as GR antagonist RU486, abrogate the anticolitis effect of GP-75, thus confirming the pivotal role of macrophages in GP-75 function. We also showed that GP-75 has no toxicity in mice. Overall, this is the first report that demonstrates the effect of GP-75 on macrophage reprograming and as an agent against colitis. Because G. pentaphyllum is gaining popularity as a functional food, our findings offer new perspectives on the use of gypenosides as potential nutraceuticals for medical purposes.

Probing Nanotopography-Mediated Macrophage Polarization via Integrated Machine Learning and Combinatorial Biophysical Cue Mapping.

Inflammatory responses, leading to fibrosis and potential host rejection, significantly hinder the long-term success and widespread adoption of biomedical implants. The ability to control and investigated macrophage inflammatory responses at the implant-macrophage interface would be critical for reducing chronic inflammation and improving tissue integration. Nonetheless, the systematic investigation of how surface topography affects macrophage polarization is typically complicated by the restricted complexity of accessible nanostructures, difficulties in achieving exact control, and biased preselection of experimental parameters. In response to these problems, we developed a large-scale, high-content combinatorial biophysical cue (CBC) array for enabling high-throughput screening (HTS) of the effects of nanotopography on macrophage polarization and subsequent inflammatory processes. Our CBC array, created utilizing the dynamic laser interference lithography (DLIL) technology, contains over 1 million nanotopographies, ranging from nanolines and nanogrids to intricate hierarchical structures with dimensions ranging from 100 nm to several microns. Using machine learning (ML) based on the Gaussian process regression algorithm, we successfully identified certain topographical signals that either repress (pro-M2) or stimulate (pro-M1) macrophage polarization. The upscaling of these nanotopographies for further examination has shown mechanisms such as cytoskeletal remodeling and ROCK-dependent epigenetic activation to be critical to the mechanotransduction pathways regulating macrophage fate. Thus, we have also developed a platform combining advanced DLIL nanofabrication techniques, HTS, ML-driven prediction of nanobio interactions, and mechanotransduction pathway evaluation. In short, our developed platform technology not only improves our ability to investigate and understand nanotopography-regulated macrophage inflammatory responses but also holds great potential for guiding the design of nanostructured coatings for therapeutic biomaterials and biomedical implants.

The role of apoptosis, immunogenic cell death, and macrophage polarization in carbon ion radiotherapy for keloids: Targeting the TGF-ß1/SMADs signaling pathway.

Keloids, characterized by excessive extracellular matrix (ECM) deposition and aberrant fibrous tissue proliferation, present significant therapeutic challenges due to their recalcitrant and recurrent nature. This study explores the efficacy of Carbon Ion Radiotherapy (CIRT) as a novel therapeutic approach for keloids, focusing on its impact on fibroblast proliferation, apoptosis induction, immunogenic cell death (ICD), macrophage polarization, and the TGF-ß/SMAD signaling pathway. Utilizing a murine model of keloid formed by subcutaneous injection of zeocin in C57BL/6 mice, we demonstrated that CIRT effectively reduces collagenous fiber synthesis and collagen production in keloid tissues. Further, CIRT was shown to inhibit keloid fibroblast proliferation and to induce apoptosis, as evidenced by increased expression of apoptosis-related proteins and confirmed through flow cytometry and TUNEL assay. Notably, CIRT induced mitochondrial stress, leading to enhanced immunogenicity of cell death, characterized by increased expression of ICD markers and secretion of interferon-γ. Additionally, CIRT promoted a shift from M2 to M1 macrophage polarization, potentially reducing TGF-ß release and mitigating ECM deposition. Our findings suggest that CIRT mediates its therapeutic effects through the inhibition of the TGF-ß/SMAD signaling pathway, thereby attenuating ECM formation and offering a promising avenue for keloid treatment. This study underscores the potential of CIRT as an innovative strategy for managing keloids, highlighting its multifaceted impact on key cellular processes involved in keloid pathogenesis.