Promoting M2 Macrophage Research Articles

Sphingosine kinase 1 promotes M2 macrophage infiltration and enhances glioma cell migration via the JAK2/STAT3 pathway

Sphingosine kinase 1 (SPHK1) is a member of the SPHK family, enzymes essential for the phosphorylation of sphingosine to sphingosine-1-phosphate (S1P). Previous studies have revealed important roles of SPHK1 in inflammatory, anti-apoptotic, immune processes, and cancer. Although the predictive significance and possible roles of SPHK1 in gliomas have recently been examined, the precise molecular mechanisms remain unclear. We comprehensively examined SPHK1 and investigated its correlation with glioma survival time using different datasets. The correlation between SPHK1 and various cancer pathways was analyzed using the Kyoto encyclopedia of genes and genomes (KEGG) analysis. The SPHK1 influence on glioma migration was examined using transwell and wound healing experiments. M2 macrophage infiltration experiments investigated SPHK1’s role in the glioma immune microenvironment. We identified SPHK1 downstream pathways and further elucidated their regulatory relationship. Survival analysis illustrated that patients with high-SPHK1 expression, particularly glioblastoma and IDH-wildtype, tended to have a shorter survival time. The Cox regression model (COX) results demonstrated that SPHK1 was an independent prognostic factor affecting the survival of patients with glioma. Functional experiments illustrated that SPHK1 suppression led to a reduction in the migration capacity of glioma cells. Enrichment analysis and Western blotting revealed that SPHK1 functions as a JAK2/STAT3 pathway controller. The SPHK1 overexpression-induced migration was suppressed by the JAK2/STAT3 pathway suppressor (AG490). We found that SPHK1 promotes M2 macrophage infiltration. Further study indicated that SPHK1 could serve as a prognostic indicator of glioma and promote cell migration, providing new insights for glioma therapy.

The promoting effect of Balanus albicostatus cement protein 19k (Balcp19k) on wound healing by regulating fibroblast migration and relieving early-stage inflammation responses.

The high incidence of skin wounds (e.g., burns, diabetic ulcers, venous ulcers, pressure sores, and radiation injuries) remains a significant challenge in clinical settings. Dressing materials, infused with bioactive components, are essential and extensively utilized in specific circumstances. According to traditional Chinese medicine therapeutic regimens, powders made of the flesh/shells of Balanus albicostatus were used to treat sores due to their ability to alleviate inflammatory responses. Nevertheless, information is scarce regarding the effective components and the pharmacological mechanisms involved. In this work, purified Balanus albicostatus cement protein 19k (Balcp19k) was obtained as a single-component material via an E. coli-based heterologous expression system. It had the potential to promote fibroblast proliferation and migration, which were crucial for wound healing. Immunofluorescence revealed that Balcp19k treatment promoted M2 macrophage transformation in wound tissues. Correspondingly, the expression of inflammation-related genes (e.g., IL-6, TNF-α, and IFN-γ) was significantly reduced (p<0.05). Moreover, histological examination indicated that this treatment accelerated skin-wound healing by promoting collagen fiber deposition and angiogenesis, and restraining inflammatory cell infiltration in the full-thickness skin of mice. In conclusion, Balcp19k is a biocompatible, effective constituent found in Balanus albicostatus. This bioactive protein could be novel therapeutic material for wound healing, with ability to regulate fibroblast migration, alleviate early-stage inflammatory responses, and enhance collagen fiber deposition and angiogenesis.

A Hepatic Oxidative Metabolite of Palmatine Ameliorates DSS-Induced Ulcerative Colitis by Regulating Macrophage Polarization Through AMPK/NF-κB Pathway.

Palmatine (PAL) and berberine are both classified as protoberberine alkaloids, derived from several traditional Chinese herbs such as Coptis chinensis Franch. and Phellodendronchinense Schneid. These compounds are extensively used in treating dysentery and colitis. PAL is one of the crucial quality markers for these plants in the Chinese Pharmacopoeia. A key metabolite of PAL, 8-Oxypalmatine (OPAL), shows favorable anti-inflammatory activity and better safety compared to PAL, though its mechanisms in ulcerative colitis (UC) are not fully understood. This study used a dextran sodium sulfate-induced colitis mouse model to explore OPAL's effects. The results indicated that OPAL provided superior therapeutic effects to those of PAL, alleviating colitis symptoms and reducing colon inflammation by modulating pro-inflammatory (tumor necrosis factor-α, interleukin-1β, and interleukin-6) and anti-inflammatory (transforming growth factor-β and interleukin-10) cytokines. Additionally, OPAL helped rebuild the mucus barrier and upregulated tight junction proteins, thereby restoring intestinal integrity. Notably, OPAL inhibited the M1 macrophages infiltration while promoting M2 macrophage distribution in the colon. Its role in fostering M2 polarization and modulating the inflammatory cytokine profile was further confirmed invitro. Importantly, the anti-inflammatory effects were primarily linked to AMP-activated protein kinase activation, which subsequently inhibited the nuclear factor-kappa B pathway. These findings highlight OPAL as a crucial active metabolite responsible for the therapeutic effects of PAL against UC, emphasizing its potential as a novel treatment for this condition.

Structural characterization and immunomodulatory activity of polysaccharides from the flowers of Imperata cylindrica Beauv.var. major (Nees) C.E.Hubb

BackgroundPolysaccharides are the main active components of Imperata cylindrica; however, research primarily targets its roots, with limited studies on flower-derived polysaccharides.ResultsTwo polysaccharides, FIC-1 and FIC-2, were extracted from the flowers of Imperata cylindrica using water extraction and ethanol precipitation. They were characterized by FT-IR, HPGPC, and SEM, with FIC-1 undergoing additional methylation and NMR analysis. FIC-1 was a neutral polysaccharide with a molecular weight of 5.3 kDa, while FIC-2 was an acidic polysaccharide with a molecular weight of 23.3 kDa. The two polysaccharides had distinct surface morphologies: FIC-1 had a rough, flocculent structure, while FIC-2 was smooth and lamellar. FIC-1’s main chain consists of →4)-β-D-Glcp-(1→, α-D-Glcp-(1→, →3)-β-D-Galp-(1→, →5)-α-L-Araf-(1→, and →4,6)-α-D-Manp-(1→ linkages, with side chains mainly formed by α-L-Araf-(1→ linked at the O-4 position of →4,6)-α-D-Manp-(1→. Further analysis of FIC-1 indicated that it promoted M1 macrophage polarization, activated NF-κB signaling pathway, and enhanced glycolysis and phagocytosis. While FIC-1 did not directly kill cancer cells, the cytokine-rich medium from FIC-1-stimulated macrophages significantly inhibited the proliferation of LLC1, ID8, and Hepa1-6 cancer cells.ConclusionsThese findings provide useful evidence that support the development and potential clinical application of polysaccharides derived from the flowers of Imperata cylindrica.Graphical

Polyoxometalate-based injectable coacervate inhibits HCC metastasis after incomplete radiofrequency ablation via scavenging ROS

BackgroundIncomplete radiofrequency ablation (iRFA) stimulates residual hepatocellular carcinoma (HCC) metastasis, leading to a poor prognosis for patients. Therefore, it is imperative to develop an effective therapeutic strategy to prevent iRFA-induced HCC metastasis.ResultsOur study revealed that iRFA induced an abnormal increase in ROS levels within residual HCC, which enhanced tumor cell invasiveness and promoted macrophage M2 polarization, ultimately facilitating HCC metastasis. Molybdenum-based polyoxometalate (POM) is an excellent ROS-scavenging nanocluster, but its size is too small to be easily cleared by the kidneys, limiting its effectiveness in scavenging iRFA-induced ROS. To overcome this limitation, we synthesized an injectable POM-loaded coacervate delivery system named POM@Coa, which can sustainably scavenge iRFA-induced ROS by slowly releasing POM. POM@Coa markedly reduced HCC invasiveness, reversed macrophage polarization from M2 to M1, and promoted the infiltration and activation of CD8+ T cells, ultimately inhibiting HCC metastasis. Importantly, POM@Coa showed superior therapeutic efficacy to free POM in the absence of systemic toxicity.ConclusionsPOM@Coa exhibits the potential to decrease HCC invasiveness and activate anti-tumor immunity, opening up new avenues for the safe and effective treatment and prevention of HCC metastasis when combined with RFA.

SLAMF8 Disrupts Epithelial Barrier in Chronic Rhinosinusitis with Nasal Polyps via M1 Macrophage Polarization.

Recent studies show that M1 macrophages accumulate predominantly in non-eosinophilic chronic rhinosinusitis with nasal polyps (neCRSwNP). However, the precise mechanisms regulating M1 macrophages and their impact on the epithelial barrier remain unclear. We aim to investigate the expression and regulatory role of SLAMF8, a molecule exclusively expressed in myeloid cells, in M1 macrophage polarization and its potential contribution to neCRSwNP development. We evaluated SLAMF8 expression and its correlation with clinical variables using real-time quantitative polymerase chain reaction and Western blot in sinonasal mucosa samples from CRSwNP and control subjects. Immunofluorescence staining confirmed the co-expression of SLAMF8 with macrophages. After SLAMF8 knockdown, we explored the influence on macrophage M1 polarization and the effect on epithelial-mesenchymal transition (EMT) process and tight junction integrity in epithelial cells through an indirect co-culture system of M1 macrophages with human nasal epithelial cells. SLAMF8 was highly expressed on M1 macrophages in polyp tissues, notably in neCRSwNP, and correlated with disease severity indices only in neCRSwNP. SLAMF8 knockdown in THP-1 cells reduced M1 macrophage markers (CD86, iNOS, and NLRP3) and decreased secretion of inflammatory cytokines (IL-1β, IL-6, and TNF-α). Co-culture with M1 macrophage supernatant after SLAMF8 knockdown enhanced epithelial viability, reduced EMT and apoptosis, and upregulated tight junction markers Occludin and Claudin-4 in nasal epithelial cells. SLAMF8 elevation correlates with the EMT, epithelial tight junction and disease severity in neCRSwNP. The SLAMF8 upregulation promotes M1 macrophage polarization, by which facilitates EMT and impairs nasal epithelial barrier function. SLAMF8 may represent a novel therapeutic target for neCRSwNP.

Histone lactylation regulates PRKN-Mediated mitophagy to promote M2 Macrophage polarization in bladder cancer.

Bladder cancer (BCa), particularly muscle-invasive bladder cancer (MIBC), is associated with poor prognosis, partly because of immune evasion driven by M2 tumor-associated macrophages (TAMs). Understanding the regulatory mechanisms of M2 macrophage polarization via PRKN-mediated mitophagy and histone lactylation (H3K18la) is crucial for improving treatment strategies. A single-cell atlas from 46 human BCa samples was constructed to identify macrophage subpopulations. Bioinformatics analysis and experimental validation, including ChIP-seq and lactylation modulation assays, were used to investigate the role of PRKN in M2 macrophage polarization and its regulation by H3K18la. Single-cell analysis revealed distinct macrophage subpopulations, including M1 and M2 types. PRKN was identified as a critical regulator of mitophagy in M2 macrophages, supporting their immunosuppressive function. Bulk RNA-seq and gene intersection analysis revealed a set of mitophagy-related macrophage polarization genes (Mito_Macro_RGs) enriched in mitophagy and immune pathways. Pseudotime analysis revealed that PRKN was upregulated during the M1-to-M2 transition. siRNA-mediated PRKN knockdown impaired M2 polarization, reducing the expression of CD206 and ARG1. ChIP-seq and histone lactylation modulation confirmed that H3K18la enhanced PRKN expression, promoting mitophagy and M2 polarization and thereby facilitating immune suppression and tumor progression. Histone lactylation regulated PRKN-mediated mitophagy, promoting M2 macrophage polarization and contributing to immune evasion in BCa.

IKZF1 promotes pyroptosis and prevents M2 macrophage polarization by inhibiting JAK2/STAT5 pathway in colon cancer.

Pyroptosis and macrophage pro-inflammatory activation play an important role in hepatocellular carcinoma (HCC) progression. However, the specific regulatory mechanisms remain unclear. We identified pyroptosis-related differentially expressed genes (DEGs) based on the GSE4183 and GSE44861 datasets as well as EVenn database. Expression levels of key genes were detected by qRT-PCR. IKZF1 was overexpressed in colon cancer cells and tumor-bearing mice, and its functions were assessed by various cell biology assays in vitro and in vivo. To investigate the interactions between IKZF1 and macrophages, a co-culture system was constructed. The activator RO8191 or inhibitor ruxolitinib of the JAK/STAT pathway was employed to confirm whether IKZF1 inhibited colon cancer development by regulating JAK2/STAT5 pathway. Pyroptosis-related hub genes RBBP7, HSP90AB1, and RBBP4 were highly expressed, while IKZF1, NLRP1, and PYCARD were lowly expressed. These hub genes had good performance in distinguishing colon cancer from controls. Furthermore, overexpression of IKZF1 inhibited tumor growth and promoted pyroptosis. Overexpression of IKZF1 suppressed cell proliferation, metastasis, and inactivated JAK2/STAT5 signaling pathway in colon cancer cells. Furthermore, upregulation of IKZF1 promoted M1 macrophage polarization while inhibiting M2 macrophage polarization in vivo and in vitro by inhibiting the JAK2/STAT5 signaling pathway. This study identifies IKZF1 as a potential biomarker inactivating JAK2/STAT5 pathway for colon cancer.

P0193 Oral administration of Sophora Flavescens-derived exosomes-like nanovesicles carrying CX5461 ameliorates DSS-induced colitis in mice

Abstract Background Ulcerative colitis (UC) belongs inflammatory disease with chronic and relapsing characterizations and increased-cancer risk. CX5461 has been demonstrated the important roles in autoimmune disease, immunological rejection, and macrophage-mediated vascular inflammation. However, whether CX5461 can serve as UC therapeutic drug remains unclear. The objective of this study is to investigate the therapeutic effect of oral administration of SFELNVs@CX5461 on DSS-induced colitis and its possible molecular mechanism. Methods SFELNVs were extracted and the morphology were charactered. The preparation of SFELNVs@CX5461 were electroporated and the loading efficiency of SFELNVs@CX5461 were calculated. We conducted the experiments using SFELNV, CX5461 and SFELNVs@CX5461 respectively. Proliferation and apoptosis of RAW264.7 cells were detected by flow cytometry according to the kits. C57BL/6 mice (8 weeks, 18-20g) were induced by 3% DSS in drinking water for a week to establish the colitis model. Then, DSS-induced C57BL/6 colitis mice models were orally administrated with SFELNVs@CX5461 (n=5, 80mg/kg) and SFELNVs (n=5, 80mg/kg) for 5 days. The body weight, consistency of stool, and rectal bleeding were measured each day. Finally, after sacrificing the mice, colons and main organs were obtained for the qPCR, HE, and IHC. Results Cellular uptake has shown that SFELNVs were targeted uptake by macrophages, thus increasing drug concentration. Additionally, Oral SFELNVs@CX5461 exhibited good safety and stability, as well as inflammation-targeting ability in the gastrointestinal tract of dextran sodium sulfate (DSS)-induced colitis mice. In vivo, Oral administration of SFELNVs and CX5461 could relieve mice colitis. More importantly, combined SFELNVs and CX5461 enhanced the treatment efficacy of mice colitis by inhibiting pro-inflammatory factors (TNF-α, IL-1β, and IL-6) expression and promoting M2 macrophage infiltration. Furthermore, SFELNVs promoted M2 polarization by miR4371c using miRNA sequencing. Our results suggest that SFELNVs@CX5461 represents a novel orally therapeutic drug that can ameliorate colitis, and a promising targeting strategy for safe and effective UC therapy. Conclusion In summary, SFELNVs@CX5461 represents a therapeutic strategy to UC with excellent biocompatibility due to the ability to enhance anti-inflammatory effects in vitro and in vivo to alleviate UC.

The Metabolite Indole-3-Acetic Acid of Bacteroides Ovatus Improves Atherosclerosis by Restoring the Polarisation Balance of M1/M2 Macrophages and Inhibiting Inflammation.

Emerging research has highlighted the significant role of the gut microbiota in atherosclerosis (AS), with microbiota-targeted interventions offering promising therapeutic potential. A central component of this process is gut-derived metabolites, which play a crucial role in mediating the distal functioning of the microbiota. In this study, a comprehensive microbiome-metabolite analysis using fecal and serum samples from patients with atherosclerotic cardiovascular disease and volunteers with risk factors for coronary heart disease and culture histology is performed, and identified the core strain Bacteroides ovatus (B. ovatus). Fecal microbiota transplantation experiments further demonstrated that the gut microbiota significantly influences AS progression, with B. ovatus alone exerting effects comparable to volunteer feces from volunteers. Notably, B. ovatus alleviated AS primarily by restoring the intestinal barrier and enhancing bile acid metabolism, particularly through the production of indole-3-acetic acid (IAA), a tryptophan-derived metabolite. IAA inhibited the TLR4/MyD88/NF-κB pathway in M1 macrophages, promoted M2 macrophage polarisation, and restored the M1/M2 polarisation balance, ultimately reducing aortic inflammation. These findings clarify the mechanistic interplay between the gut microbiota and AS, providing the first evidence that B. ovatus, a second-generation probiotic, can improve bile acid metabolism and reduce inflammation, offering a theoretical foundation for future AS therapeutic applications involving this strain.

Suberosin attenuates rheumatoid arthritis by repolarizing macrophages and inhibiting synovitis via the JAK/STAT signaling pathway

BackgroundRheumatoid arthritis (RA) is a systemic disease that primarily manifests as chronic synovitis of the symmetric small joints. Despite the availability of various targeted drugs for RA, these treatments are limited by adverse reactions, warranting new treatment approaches. Suberosin (SBR), isolated from Plumbago zeylanica—a medicinal plant traditionally used to treat RA in Asia—possesses notable biological activities. This study aimed to investigate the effects and potential underlying pathways of SBR on RA.MethodsTumor necrosis factor-alpha (TNF-α) induced inflammation in RA-derived fibroblast-like synoviocytes (RA-FLS), and the expression of proinflammatory mediators was assessed using q-RT PCR and ELISA after treatment with various SBR concentrations. Bone marrow-derived macrophages (BMDMs) were induced to differentiate into M1 and M2 macrophages, followed by treatment with various SBR concentrations and macrophage polarization assessment. Low-dose (0.5 mg/kg/d) and high-dose (2 mg/kg/d) SBR regimens were administered to a collagen-induced arthritis (CIA) mouse model for 21 days, and the anti-arthritic effects of SBR were evaluated. Network pharmacology and molecular docking analyses were used to predict the anti-arthritic targets of SBR. The effect of SBR on the Janus kinase/signal transducer and activator of transcription (JAK/STAT) pathway was evaluated.ResultsSBR suppressed macrophage polarization toward the M1 phenotype while enhancing their polarization toward the M2 phenotype. SBR reduced the levels of proinflammatory mediators in TNF-α-induced RA-FLS. Mechanistically, SBR inhibited the phosphorylation of the JAK1/STAT3 signaling pathway in RA-FLS and M1 macrophages and promoted the phosphorylation of the JAK1/STAT6 pathway in M2 macrophages, enhancing M2 polarization. In vivo, prophylactic treatment of low-dose SBR reduced M1 macrophage infiltration into synovial tissue, increased the proportion of M2 macrophages, and decreased the expression of inflammatory mediators in the serum and synovial tissue, alleviating synovial inflammation. SBR significantly alleviated arthritis in CIA mice through macrophage repolarization and inhibition of inflammation.ConclusionSBR significantly reduced clinical symptoms, joint pathological damage, and expression inflammatory cytokine expression in CIA mice. SBR exhibited anti-arthritic effects via the JAK1/STAT3 and JAK1/STAT6 signaling pathways, inhibiting synovial tissue inflammation and M1 macrophage polarization while promoting M2 macrophage polarization. Therefore, SBR may be an effective candidate for RA treatment.

Hydrogel loaded with cerium-manganese nanoparticles and nerve growth factor enhances spinal cord injury repair by modulating immune microenvironment and promoting neuronal regeneration

BackgroundSpinal cord injury (SCI) treatment remains a formidable challenge, as current therapeutic approaches provide only marginal relief and fail to reverse the underlying tissue damage. This study aims to develop a novel composite material combining enzymatic nanoparticles and nerve growth factor (NGF) to modulate the immune microenvironment and enhance SCI repair.MethodsCeMn nanoparticles (NP) and CeMn NP-polyethylene glycol (PEG) nanozymes were synthesized via sol–gel reaction and DSPE-mPEG modification. Transmission Electron Microscopy, Selected-Area Electron Diffraction, X-ray Diffraction and X-ray Photoelectron Spectroscopy confirmed their crystalline structure, mixed-valence states, and redox properties. Size uniformity, biocompatibility, and catalytic activity were assessed via hydrodynamic diameter, zeta potential, and elemental analysis. The Lightgel/NGF/CeMn NP-PEG composite was synthesized and characterized via electron microscopy, compression testing, rheological analysis, NGF release kinetics, and 30-day degradation studies. Both in vitro and in vivo experiments were conducted to evaluate the therapeutic effects of the composite on SCI.ResultsThe Lightgel/NGF/CeMn NP-PEG composite was successfully synthesized, exhibiting favorable physical properties. At a CeMn NP-PEG concentration of 4 µg/mL, the composite maintained cell viability and demonstrated enhanced biological activity. It also showed superior mechanical properties and an effective NGF release profile. Notably, the composite significantly upregulated the expression of nerve growth-associated proteins, reduced inflammatory cytokines, scavenged reactive oxygen species (ROS), and promoted M2 macrophage polarization by inhibiting the cyclic GMP-AMP synthase (cGAS)-stimulator of interferon genes (STING) signaling pathway. In a rat SCI model, it facilitated functional recovery and attenuated inflammation.ConclusionThe Lightgel/NGF/CeMn NP-PEG composite shows significant therapeutic promise for SCI, effectively eliminating ROS, promoting M2 macrophage polarization, reducing pro-inflammatory cytokines, and supporting neuronal regeneration. These effects substantially enhance motor function in SCI rats, positioning it as a promising candidate for future clinical applications.Graphical

Innovative treatment of age-related hearing loss using MSCs and EVs with Apelin

Utilizing single-cell transcriptome sequencing (scRNA-seq) technology, this study explores the viability of employing mesenchymal stem cells (MSCs) as a therapeutic approach for age-related hearing loss (ARHL). The research demonstrates MSCs' ability to differentiate into inner ear cell subpopulations, particularly hair cells, delivering Apelin via extracellular vesicles (EVs) to promote M2 macrophage polarization. In vitro experiments show reduced inflammation and preservation of hair cell health. In elderly mice, MSCs transplantation leads to hair cell regeneration, restoring auditory function. These findings highlight the regenerative capabilities of MSCs and EV-mediated therapeutic approaches for ARHL.

B cells recruitment promotes M2 macrophage polarization to inhibit inflammation during wound healing.

Wound healing causes heavy economic burdens for families and society, becoming a critical issue in the global healthcare system. While the role of immune cells in the wound healing process is well-established, the involvement of B cells remains poorly understood. This study aims to elucidate the essentiality of B cells in wound repair. Our findings demonstrate a rise in B cell population during the early stage of wound healing, which further intensifies during the later stage. We employed anti-CD20 antibodies to deplete B cells in mice and created a whole skin excisional wound mice model, analyzing wound closure over 12 days. B cells were isolated from the animals' spleen and co-cultured with macrophages from bone marrow. The polarization of M1 and M2 macrophages was analyzed by real-time qPCR and flow cytometry. The wound healing process in mice was observed to be considerably delayed following the elimination of B cells. The wounds exhibited a state of inflammation primarily characterized by the presence of pro-inflammatory M1 macrophages. The decrease in M2 macrophages within the local wound area resulted in impairment of the wound repair mechanism. B cell-macrophage co-culture system revealed that B cells effectively induce the polarization of macrophages towards M2-like phenotype. Furthermore, we found that follicular B cells play predominant role in modulating the polarization of M2 macrophages. Consequently, our findings indicate that B cells can be recruited to the wound site and facilitate the polarization of M2-like macrophages, thereby accelerating the healing process during wound healing.

Inhibition of Mitochondrial Succinate Dehydrogenase with Dimethyl Malonate Promotes M2 Macrophage Polarization by Enhancing STAT6 Activation.

Macrophages exhibit diverse phenotypes depending on environment status, which contribute to physiological and pathological processes of immunological diseases, including sepsis, asthma, multiple sclerosis and colitis. The alternative activation of macrophages is tightly regulated to avoid excessive activation and damage of tissues and organs. Certain works characterized that succinate dehydrogenase (SDH) altered function of macrophages and promoted inflammatory response in M1 macrophages via mitochondrial reactive oxygen species (ROS). However, the effect of succinate dehydrogenase on M2 macrophage polarization remains incompletely understood. We employed dimethyl malonate (DMM) to inhibit succinate dehydrogenase activity and took use of RNA-seq to analyze the changes of inflammatory response of LPS-activated M1 macrophages or IL 4-activated M2 macrophages. Our data revealed that inhibition of SDH with DMM increased expression of M2 macrophages-associated signature genes, including Arg1, Ym1 and Mrc1. Consistent with previous work, we also observed that inhibition of SDH decreased the expression of IL-1β and enhanced the levels of IL-10 in M1 macrophages. Additionally, inhibition of SDH with DMM inhibited the production of chemokines, such as Cxcl3, Cxcl12, Ccl20 and Ccl9. DMM also amplified the M2 macrophages-related signature genes in IL-13-activated M2 macrophages. Mechanistic studies revealed that DMM promoted M2 macrophages polarization through mitochondrial ROS dependent STAT6 activation. Blocking ROS with mitoTEMPO or inhibiting STAT6 activation with ruxolitinib abrogated the promotion effect of DMM on M2 macrophages. Finally, dimethyl malonate treatment promoted peritoneal M2 macrophages differentiation and exacerbated OVA-induced allergy asthma in vivo. Collectively, we identified SDH as a braker to suppress M2 macrophage polarization via mitochondrial ROS, suggesting a novel strategy to treatment of M2 macrophages-mediated inflammatory diseases.

ATF3 triggers M2 macrophage polarization to protect against pulp inflammation through WNT4 regulation.

Pulpitis is a common inflammatory oral disease that can lead to pulp necrosis. The aim of this study is to investigate the expression and regulatory mechanisms of ATF3, a potential therapeutic marker, in pulpitis. A mouse pulpitis model with different degrees of inflammation is established, and the expression of ATF3 in pulpitis is explored. The histological features of healthy pulp and pulpitis are analyzed by HE staining, and classical inflammatory factors are detected by immunohistochemistry (IHC). In an in vitro study, we investigate the role of ATF3 in the regulation of WNT4 transcription and explore the effects of the ATF3/WNT4 axis on the polarization of RAW264.7 macrophages, the inflammatory response and the osteogenic differentiation of human dental pulp stem/stromal cells (hDPSCs). Our results show that ATF3 is expressed at low levels in inflamed pulp tissues; overexpression of ATF3 reduces the area of pulp necrosis, decreases the level of pro-inflammatory factors, and promotes macrophage polarization toward the M2 type. Furthermore, we reveal that ATF3 binds to the WNT4 promoter region and positively regulates the expression of WNT4 and that ATF3 downregulates M1 markers and increases the expression of M2 markers by regulating WNT4 expression. In addition, ATF3 promotes the osteogenic differentiation of dental pulp stem cells. In summary, this study reveals that ATF3 promotes M2 macrophage polarization by regulating WNT4, which in turn inhibits pulpal inflammatory responses and promotes the osteogenic differentiation of dental pulp stem cells. These findings suggest that ATF3 may be a potential target for pulpitis treatment.

YTHDF1-mediated m6A modification of GBP4 promotes M1 macrophage polarization in acute lung injury

BackgroundAcute lung injury (ALI) is a severe condition with multifaceted causes, including inflammation and oxidative stress. This research investigates the influence of m6A (N6-methyladenosine) modification on GBP4, a protein pivotal for macrophage polarization, a critical immune response in ALI.MethodsUtilizing a mouse model to induce ALI, the study analyzed GBP4 expression in alveolar macrophages. By overexpressing or knocking down GBP4, the study assessed its impact on M1 macrophage polarization. The role of YTHDF1 was also explored through knockdown experiments to determine its effect on GBP4 expression and macrophage polarization.ResultsIncreased GBP4 expression was noted in ALI model mice, promoting M1 macrophage polarization. YTHDF1 was found to enhance GBP4 expression by recognizing m6A sites on its mRNA, which was linked to reduced inflammation in MLE-12 cells upon YTHDF1 knockdown.ConclusionThe study emphasizes the crucial roles of GBP4 and YTHDF1 in ALI development and immune response regulation. It suggests m6A modification as a potential therapeutic target, contributing to the understanding of ALI’s molecular mechanisms and guiding future treatment strategies.

Chiral Nanofibers of Camptothecin Trigger Pyroptosis for Enhanced Immunotherapy.

Camptothecin (CPT), a chemotherapeutic agent, demonstrates significant potential in cancer therapy. However, as a drug, CPT molecule suffers from poor water solubility, limited bioavailability, and insufficient immune response. Herein, we construct CPT nanofibers (CNF) with a right-handed chiral property via supramolecular self-assembly, which significantly overcomes the solubility barriers associated with bioavailability and improves tumor immune prognosis. The CNF exhibits high chiral asymmetry factor (gabs) (~ 0.11) and remarkable structure stability under pH 6.5 condition. By formulating chiral CNF with mitochondrial-targeted DSPE-PEG-TPP, CNF accumulates specifically in the mitochondria of cancer cells, leading to mitochondrial dysfunction and a 3.42-fold increase in reactive oxygen species (ROS) generation compared to the CPT molecule. This ROS amplification activates the caspase-1/gasdermin D (GSDMD) pathway, inducing pyroptosis that promotes M1 macrophage polarization and enhences CD8+ T-cell-dependent antitumor immunity. Consequently, CNF achieves 1.8-fold greater growth inhibition of distant tumor and reduces tumor metastasis compared to the CPT molecule. Our innovative platform, assembling CPT molecules into chiral CNF structure, is highly anticipated to overcome the current clinical limitations of CPT molecules and offer a new direction for the development of next-generation immunotherapy strategies.

Chiral Nanofibers of Camptothecin Trigger Pyroptosis for Enhanced Immunotherapy

Abstract: Camptothecin (CPT), a chemotherapeutic agent, demonstrates significant potential in cancer therapy. However, as a drug, CPT molecule suffers from poor water solubility, limited bioavailability, and insufficient immune response. Herein, we construct CPT nanofibers (CNF) with a right‐handed chiral property via supramolecular self‐assembly, which significantly overcomes the solubility barriers associated with bioavailability and improves tumor immune prognosis. The CNF exhibits high chiral asymmetry factor (gabs) (~ 0.11) and remarkable structure stability under pH 6.5 condition. By formulating chiral CNF with mitochondrial‐targeted DSPE‐PEG‐TPP, CNF accumulates specifically in the mitochondria of cancer cells, leading to mitochondrial dysfunction and a 3.42‐fold increase in reactive oxygen species (ROS) generation compared to the CPT molecule. This ROS amplification activates the caspase‐1/gasdermin D (GSDMD) pathway, inducing pyroptosis that promotes M1 macrophage polarization and enhences CD8+ T‐cell‐dependent antitumor immunity. Consequently, CNF achieves 1.8‐fold greater growth inhibition of distant tumor and reduces tumor metastasis compared to the CPT molecule. Our innovative platform, assembling CPT molecules into chiral CNF structure, is highly anticipated to overcome the current clinical limitations of CPT molecules and offer a new direction for the development of next‐generation immunotherapy strategies.

IFN-τ Maintains Immune Tolerance by Promoting M2 Macrophage Polarization via Modulation of Bta-miR-30b-5p in Early Uterine Pregnancy in Dairy Cows.

Pregnancy failure in the first trimester of cows significantly impacts the efficiency of the dairy industry. As a type I interferon exclusively to ruminants, IFN-τ plays a key role in maternal recognition and immune tolerance of fetuses. Macrophages are the most common immune cells within the ruminant endometrium. Nevertheless, deeply analyzing the mechanisms of IFN-τ regulating macrophage polarization still needs further study. In this study, a notable decline of bta-miR-30b-5p expression via the increase of SOCS1 was observed in uterine tissues of pregnant cows. We then confirmed that the 3'UTR of SOCS1 was to be directly targeted by bta-miR-30b-5p. After that, we demonstrated that this obviously promoted the bovine macrophages (BoMac) polarized to M2 through enhancing SOCS1 expression with the treatment of IFN-τ. Furthermore, we found that SOCS1 restrained the expression of the key proteins p65 and p-P65 in the NF-κB pathway. Causing, the wide range of cross-species activities of IFN-τ, therefore we established a pregnant mouse model for the future confirmation of the above mechanism. The results verified that IFN-τ significantly improved this mechanism and maintained normal pregnancy status in mice, but miR-30b-5p significantly reduced the M2 polarization by inhibiting SOCS1, which activated the NF-κB signaling pathway, and then leading to the failure of embryo implantation. All these results indicated that IFN-τ can regulate immune tolerance during pregnancy by promoting M2 macrophage polarization through inhibiting bta-miR-30b-5p targeting SOCS1 to deactivate the NF-κB signaling pathway.