M2 Macrophage Polarization Research Articles

Reactive oxygen species-responsive polydopamine-PtCuTe nanoparticle-loaded microneedle system for promoting the healing of infected skin wounds

Nanozymes, known for their high efficiency in scavenging reactive oxygen species (ROS), have received significant attention in promoting the healing of infected wounds. Herein, we reported a novel multifunctional PDA-PtCuTe nanozyme with excellent ROS scavenging, antibacterial, pro-angiogenic, anti-inflammatory, and immune regulatory properties. It was loaded onto microneedles (PTPP-MN) for treating infected wounds. In vitro experiments demonstrated its ability to scavenge ROS and exhibit antioxidant properties. Compared to PT-MN (11.03 ± 3.37 %) and PTP-MN (42.30 ± 2.60 %), the ROS scavenging rate of PTPP-MN reached 63.63 ± 4.42 %. The microneedle exhibits good biocompatibility, stimulating fibroblast migration, endothelial angiogenesis, and M2 macrophage polarization. Additionally, it effectively eliminates ROS and provides antioxidant effects while inhibiting the viability of S. aureus and E. coli. Animal experiments showed that the PTPP-MN group achieved near-complete re-epithelialization by the third day compared to other groups. Histological observations revealed that the PTPP-MN group exhibited enhanced granulation tissue formation, epithelial regeneration, and angiogenesis. After PTPP-MN treatment, the local immune response shifted from a pro-inflammatory state to a pro-regenerative state. Our results indicate that PTPP-MN holds great promise for infected wound healing with reduced scar formation.

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.

MMP2 enzyme-responsive extracellular vesicles as dual-targeted carriers to promote the phagocytosis of macrophages

Combination therapy using inhibition of tumor cell escape and alteration of the tumor microenvironment offers a new strategy for cancer treatment. This study aimed to develop an extracellular vesicle (EV) carrier that regulates tumor cells and the tumor microenvironment to achieve efficient tumor immunotherapy. The ligand modified on carriers targets the immune checkpoint CD47 protein, blocking tumor cell escape. This ligand is cleaved by the MMP2 enzyme and assembles into nanofibers, extending the retention time in the tumor. The carriers target the CD206 protein, enabling efficient uptake by M2 macrophages. Carriers with a high density of ligands (anti-CD206) exhibit strong receptorligand interactions with tumor cells. Due to their high rigidity, these EVs have difficulty deforming during the transmembrane process, reducing resistance and resulting in low uptake efficiency by M2 cells. The optimal uptake efficiency by M2 macrophages is achieved when the mass ratio of ligand to EVs is 1:25. Crocin loaded in EVs facilitates the polarization of M2 macrophages into M1 cells, which can phagocytize tumor cells. This study reveals a potential strategy for using extracellular vesicles in tumor treatment.

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.

Benzoic Acid potentiates intestinal IgA response in broiler chickens against Salmonella enterica Serovar Typhimurium infection

As a feed additive, Benzoic Acid (BA) has been demonstrated to significantly enhance feed conversion efficiency, regulate gastrointestinal pH, and improve overall animal health. Young animals, highly susceptible to S. Typhimurium infection, suffer from high mortality rates and substantial economic losses due to this pathogen. Despite promising indications of BA's immunomodulatory potential in boosting intestinal immunity, its underlying mechanisms remain insufficiently understood. This study investigates how BA strengthens intestinal anti-infection defenses in young animals via immunomodulatory pathways, focusing on its impact on macrophage polarization and IgA-mediated immune responses. Employing in vitro cell experiments and animal models, we examined the macrophage phenotypic alterations following BA treatment. We assessed the expression of immune-related genes in the intestine through immunofluorescence staining, Western blotting, and quantitative real-time PCR. The results demonstrate that BA promotes M2 macrophage polarization by activating the mTOR/PPAR-γ/STAT3 signaling pathways. Furthermore, BA enhances the intestinal expression of the polymeric immunoglobulin receptor (PIgR), B-cell activating factor (BAFF) from the TNF family, and activation-induced cytidine deaminase (AID), thereby enhancing IgA production by B-cells. These results underscore the potential of BA to bolster innate immune functions in young chickens, mitigate intestinal damage caused by S. Typhimurium infection, and ultimately promote both animal health and food safety.

Sex-specific transcriptomic effects of low-dose inorganic arsenic exposure on bone marrow-derived macrophages

Both tissue-resident macrophages and monocytes recruited from the bone marrow that transform into tissue-resident cells play critical roles in mediating homeostasis as well as in the pathology of inflammatory diseases. Inorganic arsenic (iAs) is the most common drinking water contaminant worldwide and represents a major public health concern. There are numerous diseases caused by iAs exposure in which macrophages are involved, including cardiovascular disease, cancer, and increased risk of (respiratory) infectious diseases. Notably, prenatal iAs exposure is also associated with negative birth outcomes and developmental immunotoxicity (DIT) contributing to long-term adverse outcomes of these immune-related diseases. Therefore, understanding the effects of iAs exposure on macrophages, particularly during immune development or tissue injury and inflammation, can help us better grasp the full range of arsenic immunotoxicity and better design therapeutic targets for iAs-induced diseases particularly in exposed populations. In contrast to prior published studies which often only focused on the effect of iAs on mature macrophages after development, in this study, we analyzed the transcriptome of M0-, M1- and M2-polarized male and female murine bone marrow-derived macrophages (BMDMs) which were exposed to iAs during the differentiation phase, as a model to study iAs (developmental) immunotoxicity. We identified differentially expressed genes by iAs in a sex- and stimulation-dependent manner and used bioinformatics tools to predict protein-protein interactions, transcriptional regulatory networks, and associated biological processes. Overall, our data suggest that M1-stimulated, especially female-derived, BMDMs are most susceptible to iAs exposure during differentiation. Most notably, we observed significant downregulation of major proinflammatory transcription factors, like IRF8, and its downstream targets, as well as genes encoding proteins involved in pattern recognition and antigen presentation, such as TLR7, TLR8, and H2-D1, potentially providing causal insight regarding the role of (early-life) arsenic exposure in perturbing immune responses to infectious diseases. We also observed significant downregulation of genes involved in processes crucial to coordinating a proinflammatory response including leukocyte migration, differentiation, and cytokine and chemokine production and response. Finally, we discovered that 24 X-linked genes were dysregulated in iAs-exposed female stimulation groups compared to only 3 across the iAs-exposed male stimulation groups. These findings elucidate the potential mechanisms underlying the sex-differential iAs-associated immune-related disease risk.

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.

Hyaluronic acid act as drug self-assembly chaperone and co-assembled with celalstrol for ameliorating non-alcoholic steatohepatitis

Nanoformulations of therapeutic drugs with diverse chemical structures are often complex to produce and lack a universal synthesis approach. Herein, we demonstrate that hyaluronic acid (HA) can function as an assembly chaperone, facilitating the formulation of various chemical compounds into nanoparticles without necessitating chemical modification. As a proof of concept, celastrol-HA co-assembled nanoparticles (CHNPs) were synthesized and utilized in the multifactorial treatment of non-alcoholic steatohepatitis (NASH). By simply blending an aqueous solution of HA and celastrol, we achieved the formation of homogeneous, stable, and biocompatible nanoparticles, effectively addressing the critical issues associated with celastrol's poor water solubility and high systemic toxicity. of celastrol. Ex vivo and in vivo experiments demonstrated that CHNPs ameliorated NASH by inhibiting macrophage M1 polarization, reducing liver inflammation and lipid deposition, and improving metabolic disorders. Furthermore, CHNPs reduced systemic toxicity and enhanced the bioavailability of celastrol. The simplicity of the HA-based nanoparticles may facilitate the development of translational nanomedicines.

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.

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.

HBSP inhibits tubular cell pyroptosis and apoptosis, promotes macrophage M2 polarization, and protects LPS-induced acute kidney injury.

Sepsis-associated acute kidney injury (AKI) has high morbidity and mortality, but without cause-specific treatment. Erythropoietin derived Helix B surface peptide (HBSP) alleviates AKI, whereas its underlying mechanisms remain to be further explored. Here, the effects of HBSP on pyroptosis, apoptosis, macrophage polarization and repair were investigated in lipopolysaccharide (LPS)-induced AKI mouse model and cultured kidney epithelial cells. Systemic inflammation, compromised renal function and histology were demonstrated in LPS-treated mice, with upregulated pyroptotic and apoptotic key proteins in the kidneys including GSDMD-N, cleaved IL-1β, IL-18 and caspase-3. These proteins were localized in tubular areas and colocalized with aquaporin-1 (AQP1), with increased F4/80+ M1 macrophages. However, HBSP mitigated pyroptosis, apoptosis and inflammation, and promoted macrophage M2 polarization. In addition, HMGB1 and erythropoietin receptor (EPOR) were increased by LPS and decreased by HBSP, both of which were positively correlated with pyroptotic and apoptotic proteins. Moreover, HBSP reduced TNF-α and IL-6 mRNA levels, as well as pyroptosis and apoptosis in LPS-stimulated TCMK-1 cells. In conclusion, HBSP inhibited tubular pyroptosis and apoptosis, EPOR expression, promoted macrophage M2 polarization, and protected against LPS-induced AKI. These findings provide new mechanistic insights into the renoprotection of HBSP, and facilitate its potential for clinical applications and therapeutic strategies in sepsis-associated AKI.

Exosomes from Adipose-Derived Mesenchymal Stromal Cells Prevent Medication-Related Osteonecrosis of the Jaw by Inhibiting Macrophage M1 Polarization and Pyroptosis.

Exosomes from mesenchymal stromal cells (MSCs) can prevent the development of medication-related osteonecrosis of the jaw (MRONJ) by promoting tooth socket wound healing; however, the exact mechanism remains to be clarified. In this study, our aim was to explore the mechanisms of exosomes derived from adipose-derived mesenchymal stromal cells (ADSCs) in preventing MRONJ by focusing on macrophage M1 polarization and pyroptosis. The MRONJ model was established by theadministration of zoledronate and tooth extraction. Exosomes isolated from the supernatant of ADSCs were mixed with hydrogel and locally injected into the extraction site after tooth extraction. Stereoscope observations, micro computed tomography (microCT), and histological analysis were used to assess tooth socket wound healing. The results showed that exosomes could effectively avoid MRONJ via accelerating gingival wound healing and tooth socket bone regeneration. Mechanistically, zoledronate triggered the NF-κB signaling pathway and promoted p65 transferring into the nucleus in macrophages, resulting in macrophage M1 polarization and pyroptosis-mediated tissue inflammation, while exosomes could reduce macrophage pyroptosis and pro-inflammation cytokines release by suppressing the NF-κB/NLRP3/IL-1β axis. Additionally, IL-1RA derived from exosomes plays a key role in preventing MRONJ. Pyroptosis-related and inflammatory-related processes were upregulated in MRONJ patients further confirmed by assessing MRONJ gingival samples and healthy gingival tissues. ADSCs-derived exosomes could effectively promote tooth socket healing and prevent MRONJ by inhibiting M1 macrophage activation and pyroptosis by blocking the NF-κB/NLRP3/IL-1β axis.

Cinobufagin modulates vasculogenic mimicry and tumor-associated macrophages to inhibit ovarian cancer progression

BackgroundOvarian cancer is among the most prevalent malignant tumors affecting women. While conventional therapies like surgery do provide some measure of disease control, they are accompanied by evident side effects that may readily result in drug resistance. Cinobufagin (HCS) is a water-soluble active component extracted from the dried skin of the Bufo gargarizans. Clinical studies have demonstrated its significant anti-tumor effects. MethodsTranscriptome sequencing identified Forkhead Box S1 (FOXS1)-related targets, and Western blot analysis evaluated the expression levels of vasculogenic mimicry (VM)-related proteins and pathway proteins after cinobufagin intervention. Immunofluorescence and ELISA were used to detect the effects of cinobufagin on M1 and M2 macrophage markers. Additionally, a co-culture model of Skov3 cells and macrophages was established to study the effects of cinobufagin on tumor-associated macrophage polarization. ResultsCinobufagin significantly inhibited the growth of Skov3 ovarian cancer cells both in vitro and in vivo. Additionally, cinobufagin decreased the expression levels of VM-related proteins, thereby affecting vasculogenesis both in vitro and in vivo. Transcriptomic analysis revealed that the regulation of the FOXS1 gene contributed to this inhibitory effect. In the co-culture system, we found that cinobufagin inhibited IL-4-induced M2 macrophage polarization. Overexpression of FOXS1 in Skov3 cells enhanced the activity of the C-C motif chemokine ligand 2/ receptor 2 (CCL2/CCR2) pathway, which was suppressed by cinobufagin, thus affecting the tumor microenvironment. ConclusionCinobufagin suppressed vasculogenic mimicry by regulating the FOXS1 gene and inhibited M2 macrophage polarization through the CCL2/CCR2 pathway, thereby affecting the tumor microenvironment.

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.

TissueGene-C induces anti-inflammatory activity and M2 macrophage polarization via activation of prostaglandin E2 signaling

Osteoarthritis (OA) is the most common form of degenerative joint disease that commonly affects the knees, hips, and hands. OA is a mechano-inflammatory disease characterized by low-grade inflammation, which results in the breakdown of the cartilage extracellular matrix (ECM) within joints, leading to pain, stiffness, and inflammation. TissueGene-C (TG-C) is a cell and gene therapy investigational drug for treating knee OA that comprises human allogenic chondrocytes and an irradiated modified cell line stably expressing transforming growth factor-β1 (TGF-β1). Previous preclinical animal studies have shown that TG-C provides pain relief via its anti-inflammatory effects and cartilage structural improvement in rat OA model. The goal of this study was to investigate the mechanism of action of TG-C, explore its anti-inflammatory activity, and identify the TG-C-derived active factor(s) responsible for its efficacy. Our results showed that TG-C induces the polarization of M2 macrophages and the upregulation of interleukin-10 (IL-10) and interleukin-1 receptor antagonist (IL-1ra) while inhibiting tumor necrosis factor alpha (TNF-α) expression. Additionally, this study identified prostaglandin E2 (PGE2) as the main bioactive factor responsible for the anti-inflammatory activity of TG-C. Our results demonstrated that PGE2 is expressed by the TG-C chondrocyte component and modulated by TGF-β1 derived from the second component of TG-C. Finally, the present study provides insight into the mechanism of action of TG-C in the treatment of OA.

FTY720P-treated macrophages in PEG-4MAL hydrogels promote oral wound healing

Oral wound healing involves hemostasis, inflammation, proliferation, and tissue remodeling. The oral cavity is a complex wound healing environment due to the presence of saliva, a high bacterial burden and ongoing physical trauma from eating. The inflammatory component of wound healing balances the polarization of macrophages in healing tissues between M1 inflammatory macrophages and M2 anti-inflammatory macrophages. M2 macrophages secrete anti-inflammatory and pro-regenerative cytokines and chemokines which aid wound healing. Fingolimod or FTY720, an FDA-approved sphingosine-1-phosphate (S1P) modulator, has been implicated in inducing the polarization of macrophages to the M2 phenotype. In this study, we investigated if macrophage pre-treatment with phosphorylated FTY720P (FTY720P), the bioactive form of the drug, in a PEG-4MAL hydrogel promotes improved oral wound healing in a critically sized oral mucosal defect model. Using cytokine dot blots and Luminex cytokine assays, FTY720P-treated murine RAW 264.7 and human THP1-differentiated macrophages in PEG-4MAL hydrogels secreted chemokines and cytokines known to regulate inflammation (e,g., IL-4, IL-13), induce macrophage M2 polarization (e.g., CCL6, CCL22), leukocyte migration (e.g., CXCL2, CCL2, CCL12, CCL22), angiogenesis (e.g.,VEGF), and epithelization (e.g., IL-1, IL17, IL22). In vitro, FTY720P-treated cells induced chemotaxis of macrophages and fibroblasts in transwell assays, and oral epithelial scratch wound closure. In a murine oronasal fistula (ONF) model of oral wound healing, the local application of FTY720P-treated macrophages in PEG-4MAL hydrogels significantly increased wound closure (75% closure) relative to non-treated cells (40% closure) and blank hydrogel controls (25% closure; p<0.0001). Flow cytometry of mouse palatal tissue showed that application of FTY720P-treated macrophage-hydrogels to ONFs significantly increased day-7 percentage of both M1 and M2 macrophages, mesenchymal stromal cells, and CD19+ B cells. Significantly fewer neutrophils, monocytes, CD4+/CD8+ T cells, and endothelial cells were observed in the FTY720P-treated macrophage defects, suggesting that FTY720P-treated macrophages in hydrogels promote oral wound healing via suppression of granulation and resolution of inflammation and promoting tissue maturation. Our data provide new insights on the use of potential FTY720P-treated macrophage therapies for oral wound healing and have clinical implications for cleft palate and oral surgery.

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.