M2 Macrophage Polarization Research Articles

Histone Lactylation-Driven GPD2 Mediates M2 Macrophage Polarization to Promote Malignant Transformation of Cervical Cancer Progression.

Cervical cancer (CC) is the most common cancer in women. This study aims to explore the molecular mechanism of lactate secreted by CC cells modulating macrophage polarization in CC via histone lactylation. Normal cervical epithelium (NCE), low-grade squamous intraepithelial lesion (LSIL), high-grade squamous intraepithelial lesion (HSIL), and cervical squamous cell carcinoma (CESC) were collected to assess H3K18la level and macrophage infiltration. Macrophages were incubated with SiHa cell-derived conditioned medium to detect M1 and M2 markers. NCE, HSIL, and CESC samples were used for ChIP-seq of H3K18la. Histone lactylation-dirven GPD2 was knocked down in macrophages. Compared to NCE, H3K18la level and M2 macrophage abundance were increased in LSIL, HSIL, and CESC. Lactate secreted by CC cells upregulated H3K18la and M2 markers but downregulated M1 markers in macrophages. ChIP-seq revealed that upregulated pathways in HSIL vs. NCE and CESC vs. HSIL were commonly enriched in lipid metabolism. Notably, lactate upregulated H3K18la-modified GPD2 expression in macrophages, and GPD2 knockdown reversed lactate induction to M2 macrophages. Collectively, lactate secreted by CC cells upregulates GPD2 via histone lactylation, thereby promoting M2 macrophage polarization in CC. This study provides new insights into the role of histone lactylation in macrophage polarization in the malignant transformation of CC.

Extracellular vesicle-packaged miR-4253 secreted by cancer-associated fibroblasts facilitates cell proliferation in gastric cancer by inducing macrophage M2 polarization

ABSTRACT Cancer-associated fibroblasts (CAFs) can interact with macrophages in the tumor microenvironment by secreting extracellular vesicles (EVs), thereby affecting tumor progression. However, the mechanisms of CAF-secreted EVs in gastric cancer (GC) remain not well understood. Here, we investigated the effect of CAF-EVs on macrophage polarization in GC and the underlying mechanisms. Macrophage polarization was evaluated using flow cytometry and quantitative real-time polymerase chain reaction. GC cell proliferation was determined using cell counting kit-8, EdU, and colony formation assays. The molecular mechanism was explored using microarray analysis, dual-luciferase reporter assay, and RNA pull-down analysis. The results showed that CAFs secreted EVs that inhibit macrophage M1 polarization and promote M2 polarization. Moreover, miR-4253 expression was increased in CAF-EVs, and inhibition of miR-4253 reversed the macrophage polarization induced by EVs. IL6R was identified as the target of miR-4253. Additionally, macrophages treated with EVs that encapsulated miR-4253 promote GC cell proliferation. In conclusion, CAF-secreted EVs packaging miR-4253 facilitate macrophage polarization from M1 to M2 phenotype by targeting IL6R, thereby accelerating GC cell proliferation. The findings suggest that EV-encapsulated miR-4253 may be a promising therapeutic target of GC.

Mechanisms and treatment of atherosclerosis: focus on macrophages

Macrophages are the basic mediators and coordinators of various types of chronic inflammation and play a crucial role in the formation and development of atherosclerosis (AS). In the complex microenvironment of atherosclerotic plaques, macrophages of different sources are exposed to different signal stimuli and thus polarized into various subpopulations. Various types of macrophages with predominantly M1 and M2 phenotypes also play different regulatory roles in the initiation and progression of AS. Lipid-lowering drugs, mainly statins, are widely used in clinical practice, but the adverse reactions are obvious and there is a lack of personalized treatment. Emerging targeted macrophage and Traditional Chinese medicine (TCM)-related therapies can regulate the cellular microenvironment, inhibit the polarization of M1 macrophages, and promote the activation of M2 macrophages, providing new ideas for the prevention and treatment of AS.

Empagliflozin Attenuates High-Glucose-Induced Astrocyte Activation and Inflammation via NF-κB Pathway

Sodium-glucose cotransporter-2 (SGLT2) inhibitors regulate blood glucose levels in patients with type 2 diabetes mellitus and may also exert anti-inflammatory and anti-atherosclerotic effects by promoting M2 macrophage polarization. Although SGLT2 is expressed in brain regions that influence glucose balance and cognitive function, its roles in the central nervous system are unclear. This study investigated the effects of empagliflozin (EMPA), an SGLT2 inhibitor, on hypothalamic inflammation associated with metabolic diseases. Mice were subjected to a high-fat diet (HFD) for varying durations (3 d, 3 weeks, and 16 weeks) and treated with EMPA for 3 weeks (NFD, NFD + EMPA, HFD, HFD + EMPA; n = 5/group). EMPA regulated the expression of astrocyte markers and pro-inflammatory cytokine mRNA in the hypothalamus of HFD-induced mice, which was linked to regulation of the NF-κB pathway. Under hyperglycemic conditions, EMPA may mitigate hypothalamic inflammation by modulating astrocyte activation via the NF-κB pathway. Our findings demonstrated that EMPA possesses therapeutic potential beyond merely lowering blood glucose levels, opening new avenues for addressing inflammation and providing neuroprotection in metabolic disease management.

Wide‐Spectrum Nano‐Antibiotics Based on TPA‐Py@AuNCs⊂BSA for Multimodal Synergistic Therapy of Drug‐Resistant Bacteria and Wound Infections

ABSTRACTTo meet the high requirements of biomedical applications in antimicrobial agents, it is crucial to explore efficient nano‐antimicrobial agents with no resistance and good biocompatibility for treating infected wounds. In this study, composite nano‐antibiotic TPA‐Py@AuNCs⊂BSA nanoparticles (TAB NPs) are prepared using hollow mesoporous Au nanocages (AuNCs) loaded with a photosensitizer (namely TPA‐Py) with D‐π‐A structure showing aggregation‐induced emission properties. When TPA‐Py is encapsulated in the cavity of AuNCs, its fluorescence is suppressed. In the presence of photothermal induction, TPA‐Py can be released from the AuNCs, allowing for the restoration of fluorescence illumination and the specific imaging of Gram‐positive bacteria. TAB NPs demonstrate outstanding antimicrobial activity against a variety of bacteria, and this multimodal antimicrobial property does not lead to the development of bacterial resistance. In vitro experiments show that TAB NPs could eliminate bacteria and ablate bacterial biofilm. In vivo experiments show that the synergistic antimicrobial effect of TAB NPs has a significant positive impact on the treatment of infected wounds, including rapid antibacterial action, promotion of M2 macrophage polarization, and enhancement of chronic wound healing. This study provides an effective strategy for developing wide‐spectrum nano‐antibiotics for the ablation of bacterial biofilms and the treatment of infected wounds.

TYROBP promotes the spread of pancreatic cancer by causing M2 TAM polarization.

M2-polarized tumor-associated macrophages (M2 TAMs) are known to promote cancer progression, and exosomes are crucial mediators of communication within the tumor microenvironment (TME). However, the specific role of exosomes derived from M2 TAMs in pancreatic cancer (PC) progression remains poorly understood. Tyrosine kinase binding protein (TYROBP, also known as DAP12 for DNAX activating protein-12) is a transmembrane signal transduction polypeptide that interacts with immune cell receptors, influencing cellular functions via signal transduction pathways. TYROBP is prominently found in M2 TAMs exosomes, facilitating its transfer to PC cells and suggesting a potential role in PC pathogenesis. This study initially confirmed the presence of TYROBP in M2 TAMs exosomes and its transfer to PC cells via exosomes. The impact of TYROBP on PC proliferation, apoptosis, migration, and invasion was investigated. Special attention was given to TYROBP's influence on PC metastasis and its underlying mechanisms, focusing particularly on the CD44/AKT/ERK signaling pathway. TYROBP expression in PC cells did not significantly affect tumor cell proliferation or apoptosis but demonstrated a notable inhibitory effect on migration and invasion, which was mediated through the CD44/AKT/ERK pathway. Both in vivo and in vitro experiments consistently showed that TYROBP enhanced PC metastasis. This study elucidates that TYROBP plays a direct role in promoting PC metastasis through its association with M2 TAMs polarization. Therefore, TYROBP represents a potential novel therapeutic target for interventions aimed at combatting PC progression.

Nicotine promotes M2 macrophage polarization through α5-nAChR/SOX2/CSF-1 axis in lung adenocarcinoma

α5-nicotinic acetylcholine receptor (α5-nAChR) plays a vital part in lung adenocarcinoma (LUAD). However, it is not comprehensively understood that how the α5-nAChR affects LUAD. Through diverse bioinformatics analyses and immunohistochemistry, the expressions of α5-nAChR and SOX2 as well as their relations were dissected. α5-nAChR regulated the differentiation of monocytes into M2 macrophages by targeting the STAT3/SOX2/CSF-1 signaling in the coculture system by western blotting and ChIP. α5-nAChR-mediated macrophage-mediated LUAD cell migration via SOX2/CSF-1 signaling in the cocultured medium. Correlations of α5-nAChR, SOX2 and M2 phenotype tumor-associated macrophages (TAMs) were validated in mouse LUAD models and clinical samples. α5-nAChR expression was connected to SOX2 expression, smoking and bad prognosis of LUAD among clinical samples. Nicotine-induced SOX2 expression was mediated by α5-nAChR via STAT3. Additionally, SOX2-mediated macrophage colony-stimulating factor (CSF-1) expression contributed to LUAD progression in vitro. Furthermore, α5-nAChR expression was strongly linked to pSTAT3, SOX2 and M2 macrophage marker CD206 expression and negatively correlated with M1 macrophage marker CD86 expression in vivo. It is indicated that M2 macrophages are mediated by the new α5-nAChR /SOX2/CSF-1 axis in nicotine-related LUAD, which is a potential therapeutic strategy for cancer.

IGF2BP3/CTCF Axis-Dependent NT5DC2 Promotes M2 Macrophage Polarization to Enhance the Malignant Progression of Lung Squamous Cell Carcinomas.

Lung squamous cell carcinoma (LUSC) is a type of lung cancer that develops in the squamous cells. It is known to be promoted by the activation of various signaling pathways and the dysregulation of key regulatory molecules. One such molecule, 5'-nucleotidase domain containing 2 (NT5DC2), has been identified as a critical regulator in various cancers including lung cancer. However, there are no data regarding its role in LUSC. The mRNA expression of insulin-like growth factor 2 mRNA-binding protein 3 (IGF2BP3), CCCTC-binding factor (CTCF), and NT5DC2 was analyzed using quantitative real-time polymerase chain reaction (qRT-PCR), whereas their protein expression was assessed using a western blotting assay. Cell proliferation was determined using a cell counting kit-8 (CCK-8) assay. Cell apoptosis, CD11b expression, and CD206 expression were analyzed using flow cytometry. Tube formation was assessed through a tube formation assay. Glucose consumption, lactate production, and ATP levels were measured using colorimetric methods. The effect of NT5DC2 on the malignant progression of LUSC cells was analyzed using a xenograft mouse model assay. The levels of transforming growth factor-beta 1 (TGF-β1) and interleukin-10 (IL-10) were detected using enzyme-linked immunosorbent assays. The associations among IGF2BP3, CTCF and NT5DC2 were identified using dual-luciferase reporter assay, RNA immunoprecipitation assay and m6A RNA immunoprecipitation assay. The expression of NT5DC2 was found to be upregulated in LUSC tissues and cells when compared with normal lung tissues and normal human bronchial epithelial cells. Silencing of NT5DC2 inhibited LUSC cell proliferation, tube formation, glycolysis, M2 macrophage polarization, and tumor formation while inducing cell apoptosis. In addition, CTCF was found to transcriptionally activate NT5DC2 in LUSC cells. IGF2BP3 stabilized the mRNA expression of CTCF through m6A methylation. Further, overexpression of CTCF or NT5DC2 attenuated the effects of IGF2BP3 silencing in both NCI-520 and SK-MES-1 cells. The IGF2BP3/CTCF axis-dependent NT5DC2 promotes M2 macrophage polarization, thereby enhancing the malignant progression of LUSC. This study was the first to reveal the role of NT5DC2 in LUSC and the underlying mechanism. The result suggests that targeting the IGF2BP3/CTCF/NT5DC2 axis may have clinical significance in the treatment of LUSC.

Fetal ezrin expression affects macrophages and regulatory T cells in mouse placental decidua

Ezrin is a cross-linker protein between membrane proteins and cytosolic actin, abundantly expressed in the placenta among the ERM protein family. Ezrin gene knockout mice exhibit fetal growth restriction after gestational day (GD) 15.5. This study aimed to clarify the effect of ezrin on immune cells that influence fetal growth and immune tolerance. Ezrin heterozygous knockout (Ez+/-) mice were interbred, and the gene expressions and immune cell distributions in the placentas of wild-type (Ez+/+) and ezrin knockout (Ez-/-) fetuses were analyzed. IL-6 expression in the placenta of Ez-/- fetuses was significantly higher than in Ez+/+ fetuses at GD 15.5. The mRNA expression of IL-6 in the uterine decidua attached to Ez-/- fetuses was higher compared to that attached to Ez+/+ fetuses but not in the junctional zone and labyrinth. Classical M1 and M2 macrophages in the decidua were analyzed by flow cytometry using CD86 and CD206 as markers. M1 macrophages increased in the decidua attached to Ez-/- mice compared to Ez+/+ mice, while M2 macrophages did not increase. CD4-positive T cells showed a reduction in the decidua attached to Ez-/- fetuses. Further analysis involved the subcutaneous administration of tacrolimus in pregnant Ez+/- mice from GD 8.5 to GD 15.5, which prevented the decrease in fetal body weight and decidual CD4-positive T cells in Ez-/- mice at GD 15.5. These results suggest that impaired expression of fetoplacental-derived ezrin induces inflammatory conditions in the uterine decidua through M1 polarization of macrophages, increased IL-6, and decreased CD4-positive T cells, including Treg cells.

Treatment of silicosis with quercetin depolarizing macrophages via inhibition of mitochondrial damage-associated pyroptosis

Macrophage polarization facilitates the inflammatory response and intensified fibrosis in the silicosis microenvironment by a mechanism related to macrophage pyroptosis, although the upstream target remains poorly defined. Currently, there are few reports on the development of drugs that alleviate macrophage polarization by dampening pyroptosis. The present study aims to explore the mechanics of silica mediating macrophage polarization and to investigate whether quercetin (Que) can depolarize macrophages with this mechanism. Silica processing led to prominent M1 polarization of macrophages. Additionally, significant macrophage polarization could be detected in the lung tissue of mice with airway-perfused silica. Further investigation turned out that pronounced mitochondria damage, mtDNA cytoplasmic ectomy, and pyroptosis occurred in response to silica. Nevertheless, Que treatment could effectively attenuate silica-induced mitochondria damage and pyroptosis as demonstrated in vitro and in vivo. Further exploration presented Que could bind to TOM70 and restore silica-induced mitochondrial damage. More importantly, the M1 polarization of macrophage was depressed with the co-treatment of Que and silica, wherein the inflammatory response and pulmonary fibrosis were also mitigated without obvious damage to vital organs. In conclusion, these findings proved that silica leads to mitochondrial damage, thereby evoking pyroptosis and promoting macrophage M1 polarization. Que could bind to TOM70 and restore its function, suppressing mitochondrial damage and pyroptosis, and depolarizing macrophages to reduce fibrosis, which provides a promising strategy for silicosis treatment in the future.

Injectable hyaluronate-based hydrogel with a dynamic/covalent dual-crosslinked architecture for bone tissue engineering: Enhancing osteogenesis and immune regulation

In orthopedic practice, accommodating irregular defects caused by trauma or surgery with traditional preformed bone graft substitutes is often challenging. As a result, injectable hydrogels with seed cells have garnered significant interest in bone repair due to their adaptability and minimally invasive properties. However, they cannot simultaneously achieve injectability and mechanical properties, providing a biophysical and biochemical environment for cell support. In this study, a novel injectable hydrogel system (OA hydrogel) loaded with aspirin and bone mesenchymal stem cells (BMSCs) was developed to enhance osteogenesis and immune regulation in small irregular bone defects. OA hydrogels possessed self-healing and shear-thinning properties due to dynamic/covalent hydrazone bonds between aldehyde-modified hyaluronic acid methacrylate (ADH-HAMA) and oxidized hyaluronic acid (OHA). By photopolymerization of the enclosed HAMA, the OADC hydrogel was further reinforced, making it more suitable for cell proliferation. In vitro, composite hydrogels improved the osteogenic differentiation of BMSCs. Additionally, it promoted the M2 polarization of human monocytic leukemia (THP-1) cells. In vivo, the synergistic effect of acetylsalicylic acid (ASA) and BMSCs encapsulated within the OADC hydrogel promoted new bone formation in rat calvaria through increased recruitment and polarization of M2 macrophages. These findings underscore the significant promise of hydrogels for bone tissue engineering applications.

A polysaccharide from Periplaneta americana promotes macrophage M2 polarization, exhibiting anti-inflammatory and wound-healing activities

A miscellaneous polysaccharide, PAP55–3-1, with a molecular weight of 23.03 kDa, was isolated from Periplaneta americana through extraction with dilute alkali solution, ethanol precipitation, and column chromatography purification. Structural analysis shows that PAP55–3-1 is mainly composed of five monosaccharides: galactosamine hydrochloride, glucosamine hydrochloride, galactose, glucose and mannose. Its main glycosidic bonds are: Manp-(1→, Galp-(1→, →3)-Galp-(1→, →3,6)-Manp-(1→, →2,6)-Manp-(1→, →6)-Manp-(1→, →4)-Galp-(1→, →6-Glcp-(1→, →6)-Galp-(1→, →2)-Manp-(1 →, →3,4)-Glcp-(1→, →3,6)-Galp-(1→. In vitro experiments demonstrated that PAP55–3-1 can effectively inhibit reactive oxygen species (ROS) and O2− production following H2O2−induction. After H2O2−induction, HIF-1α (hypoxia-inducible factor) was translocated in mitochondria PAP55–3-1 increased localization of HIF-1α was located on mitochondria to maintain the stability of mitochondrial function stability, thereby effectively inhibiting H2O2-induced mitochondrial oxidative damage. Additionally, PAP55–3-1 inhibited the M1 polarization of macrophages stimulated by H2O2 and promoted the phenotype polarization of macrophages from M1 to M2, displaying anti-inflammatory and pro-repair properties. In vivo experimental results indicated that PAP55–3-1 promoted wound healing in mice. Immunohistochemical experiments revealed a reduction in CD68 expression and increase in CD206 expression in both positive and the high-dose polysaccharide group control group. This further demonstrated that PAP55–3-1 promotes the phenotype polarization of macrophages from M1 to M2, exerting anti-inflammatory and wound-healing activities.

Tarm1 may affect colitis by regulating macrophage M1 polarization in a mouse colitis model.

In this study, we aimed to explore the role of Tarm1 in juvenile mice with dextran sulfate sodium (DSS)-induced colitis and elucidate the mechanisms that affect intestinal barrier function. A DSS-induced pediatric inflammatory bowel disease mouse model was established using 4-week-old juvenile mice. Disease activity index and histopathological damage scores were determined using hematoxylin and eosin (H&E) staining. Tarm1, F4/80, CD68, and CD86 levels were detected using qPCR, western blotting, and immunofluorescence. Trans epithelial electric resistance (TEER) was detected using the transwell assay. Results revealed that juvenile colitis mice fed 4% DSS drinking water had increased Tarm1 expression in the colon tissue, increased macrophage M1 polarization, higher expression of pro-inflammatory cytokines, and an impaired intestinal mucosal barrier, compared with the control group. Tarm1-knockdown RAW264.7 cells inhibited lipopolysaccharide (LPS)-induced M1 polarization and attenuated barrier damage in co-cultured intestinal epithelial cells. Tarm1 expression was increased in colonic tissues of juvenile mice with colitis, and LPS-induced M1 polarization and intestinal barrier damage were attenuated in Tarm1-knockdown RAW264.7 cells. This suggests that attenuation of Tarm1 expression is a potential target for pediatric inflammatory bowel disease therapy.

Metabolomic insights into the beneficial effects of dietary purple potato on DSS-induced murine colon colitis

Inflammatory bowel disease (IBD) is characterized by disturbance in intestinal flora and metabolomic profiles. Building on previous findings that purple potato (PP) supplementation suppresses inflammation and restores intestinal barrier in dextran sulfate sodium (DSS)-treated mice, this study examined changes in the fecal metabolome in the same cohort. Mice were fed 0 % or 10 % PP for 7 weeks, with DSS administered in the fifth week of dietary treatment followed by one-week normal drinking water recovery. A total of 68 metabolites, including amino acids, fatty acids, organic acids, carbohydrates, and polyamines, were significantly altered across the groups. PP supplementation reversed changes in 13 of the 25 DSS-altered metabolites. Six microbial metabolites derived from PP polyphenols were identified and positively correlated with M2 macrophage polarization. Data suggest that dietary PP is effective in reducing inflammation and improves gut metabolites in DSS-induced colitis mice, offering a potential dietary therapy for managing IBD.

Therapeutic potential of mesenchymal stem cell-derived extracellular vesicles: A focus on inflammatory bowel disease.

Mesenchymal stem cell-derived extracellular vesicles (MSC-EVs) have emerged as key regulators of intercellular communication, orchestrating essential biological processes by delivering bioactive cargoes to target cells. Available evidence suggests that MSC-EVs can mimic the functions of their parental cells, exhibiting immunomodulatory, pro-regenerative, anti-apoptotic, and antifibrotic properties. Consequently, MSC-EVs represent a cell-free therapeutic option for patients with inflammatory bowel disease (IBD), overcoming the limitations associated with cell replacement therapy, including their non-immunogenic nature, lower risk of tumourigenicity, cargo specificity and ease of manipulation and storage. This review aims to provide a comprehensive examination of the therapeutic efficacy of MSC-EVs in IBD, with a focus on their mechanisms of action and potential impact on treatment outcomes. We examine the advantages of MSC-EVs over traditional therapies, discuss methods for their isolation and characterisation, and present mechanistic insights into their therapeutic effects through transcriptomic, proteomic and lipidomic analyses of MSC-EV cargoes. We also discuss available preclinical studies demonstrating that MSC-EVs reduce inflammation, promote tissue repair and restore intestinal homeostasis in IBD models, and compare these findings with those of clinical trials. Finally, we highlight the potential of MSC-EVs as a novel therapy for IBD and identify challenges and opportunities associated with their translation into clinical practice. The source of mesenchymal stem cells (MSCs) strongly influences the composition and function of MSC-derived extracellular vesicles (EVs), affecting their therapeutic potential. Adipose-derived MSC-EVs, known for their immunoregulatory properties and ease of isolation, show promise as a treatment for inflammatory bowel disease (IBD). MicroRNAs are consistently present in MSC-EVs across cell types and are involved in pathways that are dysregulated in IBD, making them potential therapeutic agents. For example, miR-let-7a is associated with inhibition of apoptosis, miR-100 supports cell survival, miR-125b helps suppress pro-inflammatory cytokines and miR-20 promotes anti-inflammatory M2 macrophage polarisation. Preclinical studies in IBD models have shown that MSC-EVs reduce intestinal inflammation by suppressing pro-inflammatory mediators (e.g., TNF-α, IL-1β, IL-6) and increasing anti-inflammatory factors (e.g., IL-4, IL-10). They also promote mucosal healing and strengthen the integrity of the gut barrier, suggesting their potential to address IBD pathology.

Qingrexiaoji Recipe Regulates the Differentiation of M2 TAM via miR-29 in GC.

Gastric cancer, one of the most familiar adenocarcinomas of the gastrointestinal tract, ranks third in the world in cancer-related deaths. Traditional Chinese medicine can suppress the growth of tumors, and the underlying mechanism may be associated with the tumor microenvironment. Here, we investigated the anti-cancer effects of the Qingrexiaoji recipe on gastric cancer and the underlying molecular mechanism. An in vivo nude mouse model was established, and the expression of CD206, CD80, and M2 phenotype-related proteins (Arg-1, Fizz1) was obtained by flow cytometry and western blotting. The expressions of the M2 phenotype-related cytokines were examined by ELISA. Qingrexiaoji recipe inhibited gastric tumor growth and downregulated the expression of CD206, IFN-γ, IL-13, IL-4, and TNF-α in vivo. Qingrexiaoji recipe deceased M2 phenotypic polarization by upregulating microRNA (miR)-29a-3p level. Luciferase activity assays showed that HDAC4 is a potential target of miR-29a-3p. In cells co-transfected with HDAC4 siRNA and miR-29a-3p inhibitor and treated with IL-4 and Qingrexiaoji recipe, the miR-29a-3p inhibitorinduced increase of M2 phenotypic polarization was reversed. In summary, these results suggested that the Qingrexiaoji recipe regulated M2 macrophage polarization by regulating miR-29a-3p/HDAC4, providing a different and innovative treatment for gastric cancer.

Subcutaneously transplanted xenogeneic protein recruits treg cells and M2 macrophages to induce browning of inguinal white adipose tissue.

To study whether subcutaneously embedding xenogeneic protein threads or synthetic polymer absorbable threads can improve obesity phenotypes and metabolic conditions, and to further explore its underlying mechanism. Thirty-six 8-week-old ob/ob mice were randomly allocated to three groups, respectively, receiving catgut embedding, PGA thread embedding or sham treatment bilaterally to the groin. Individual parameters including weight, food intake, and core temperature are recorded and metabolism assessment, energy expenditure analysis, and PET/CT scanning are also performed at fixed timepoints. After surgical incision, the inguinal white adipose tissue was histologically examined and its expression profile was tested and compared among groups 4 weeks and 12 weeks after operation. Catgut embedding reduced weight gain and improved metabolic status in ob/ob mice. Browning of bilateral inguinal WAT (white adipose tissue) was induced after catgut embedding, with massive infiltration of Treg cells and M2 macrophages in the tissue slices of fat pads. IL-10 and TGF-β released by Treg cells targeted macrophages and the induced M2 macrophages increased the expression of thermogenic and anti-inflammatory genes in fat. The secretion of catecholamines by polarized M2 macrophages led to the activation of β3-AR-related pathways in adipocytes and the browning of adipose tissue. Abdominal subcutaneous catgut embedding has the potential to combat obesity through the induction of WAT browning mediated by infiltrated Treg cells and macrophages.

Characterizing dynamic tumor-immune interactions in lung adenocarcinoma through orthotopic allograft modeling.

The major clinical challenge in lung cancer immunotherapy is drug resistance. Therefore, establishing efficient orthotopic lung cancer mouse models to explore the mechanisms of drug immunotherapy resistance is highly important. In this study, we generated multiple fluorescently labeled lung adenocarcinoma cell lines from agenetically engineered KPZ mice model. Orthotopic transplantation of the primary 1F3 cell line induced a strong immune response, causing many small tumors to disappear, but some tumors evaded the immune attack and eventually formed large tumors. Tumor microenvironment analysis demonstrated that M2 macrophages play key roles in the immune response. Further mechanistic studies revealed that the chemokine CCL7 promoted the infiltration of M2 macrophages to facilitate immune escape, thereby promoting tumor growth in the orthotopic mouse model. Moreover, CCL7 levels were elevated in human lung cancer biopsies and positively correlated with M2 macrophage infiltration, and high CCL7 levels predicted advanced pathological stage and poor survival in lung cancer patients. Overall, we established a visualized and orthotopic mouse model with fluorescently labeled cells to better dissect the tumor microenvironment of lung cancer and define the critical role of CCL7 in promoting M2 macrophage polarization and tumorigenesis, providing new preclinical tools and potential targets for lung cancer immunotherapy.

Harnessing the Power of Non-diabetic Benefits of Metformin Derived from <i>Galega officinalis</i>: Focus on Wound Healing

This review explores the potential of metformin, a widely used type 2 diabetes medication, in accelerating wound healing. Derived from guanidine compounds found in <i>Galega officinalis</i>, a plant with a long history in traditional medicine, metformin has been recognized for its minimal side effects. Beyond its primary role in diabetes treatment, metformin shows promising non-diabetic benefits, particularly in wound healing. Research indicates that metformin enhances wound healing through multiple mechanisms. It increases circulating endothelial progenitor cells, improves vascular function, and regulates thrombospondin-1 levels. Metformin also modulates the AMPK/mTOR/NLRP3 inflammasome signaling pathway, promoting M2 macrophage polarization, which is crucial for tissue repair. Additionally, it reduces pro-inflammatory cytokines, increases growth factors, and decreases matrix metalloproteinases. Studies have shown that topical application of metformin accelerates wound contraction, closure, and overall healing. Furthermore, it has been found to reduce fibrosis-related gene expression and improve collagen synthesis. With chronic wounds affecting millions globally and causing significant healthcare costs, there is a pressing need for improved wound healing agents. This review advocates for further research to establish clinical guidelines on using metformin to enhance wound healing. By harnessing metformin’s pleiotropic effects, healthcare providers may offer personalized treatments that not only manage diabetes but also promote wound healing.

Eicosapentaenoic acid induces macrophage Mox polarization to prevent diabetic cardiomyopathy.

Diabetic cardiomyopathy (DC) leads to heart failure, with few effective approaches for its intervention. Eicosapentaenoic acid (EPA) is an essential nutrient that benefits the cardiovascular system, but its effect on DC remains unknown. Here, we report that EPA protects against DC in streptozotocin and high-fat diet-induced diabetic mice, with an emphasis on the reduction of cardiac M1-polarized macrophages. In vitro, EPA abrogates cardiomyocyte injury induced by M1-polarized macrophages, switching macrophage phenotype from M1 to Mox, but not M2, polarization. Moreover, macrophage Mox polarization combats M1-polarized macrophage-induced cardiomyocyte injury. Further, heme oxygenase 1 (HO-1) was identified to maintain the Mox phenotype, mediating EPA suppression of macrophage M1 polarization and the consequential cardiomyocyte injury. Mechanistic studies reveal that G-protein-coupled receptor 120 mediates the upregulation of HO-1 by EPA. Notably, EPA promotes Mox polarization in monocyte-derived macrophages from diabetic patients. The current study provides EPA and macrophage Mox polarization as novel strategies for DC intervention.