Long Non-coding RNAs Regulating Macrophage Polarization in Liver Cancer.

Primary liver cancer is the second leading cause of cancer-related death worldwide. At present, liver cancer is often in an advanced stage once diagnosed, and treatment effects are generally poor. Therefore, there is an urgent need for other powerful treatments. Macrophages are an important component of the tumor microenvironment, and macrophage polarization is crucial to tumor proliferation and differentiation. Regulatory interactions between macrophage subtypes, such as M1 and M2, lead to a number of clinical outcomes, including tumor progression and metastasis. So, it is important to study the drivers of this process. Long non-coding RNA has been widely proven to be of great value in the early diagnosis and treatment of tumors. Many studies have shown that long non-coding RNA participates in macrophage polarization through its ability to drive M1 or M2 polarization, thereby participating in the occurrence and development of liver cancer. In this article, we systematically elaborated on the long non-coding RNAs involved in the polarization of liver cancer macrophages, hoping to provide a new idea for the early diagnosis and treatment of liver cancer. Liver cancer- related studies were retrieved from PubMed. Based on our identification of LncRNA and macrophage polarization as powerful therapies for liver cancer, we analyzed research articles in the PubMed system in the last ten years on the crosstalk between LncRNA and macrophage polarization. By targeting M1/M2 macrophage polarization, LncRNA may promote or suppress liver cancer, and the references are determined primarily by the article's impact factor. Consequently, the specific mechanism of action between LncRNA and M1/M2 macrophage polarization was explored, along with the role of their crosstalk in the occurrence, proliferation, and metastasis of liver cancer. lncRNA is bidirectionally expressed in liver cancer and can target macrophage polarization to regulate tumor behavior. lncRNA mainly functions as ceRNA and can participate in the crosstalk between liver cancer cells and macrophages through extracellular vesicles. lncRNA can potentially participate in the immunotherapy of liver cancer by targeting macrophages and becoming a new biomolecular marker of liver cancer.

Tanshinol ameliorates imiquimod-induced psoriasis by inhibiting M1 macrophage polarization through suppression of the notch signaling pathway.

BACKGROUND: Psoriasis is a common immune-related chronic inflammatory skin disease, often accompanied by significant itching, and once diseased, the course of the disease lasts for most of the lifetime. Tanshinol (TAN) is an active ingredient of Salvia miltiorrhiza, which possesses pharmacological effects such as anti-inflammatory and antioxidant properties. However, the effects of TAN on psoriasis have not been widely reported. Therefore, the aim of this study was to investigate the therapeutic effects and mechanisms of TAN in psoriasis. METHODS: An imiquimod (IMQ)-induced psoriasis mouse model was constructed and treated with different doses of TAN to observe the changes in skin lesion phenotype, macrophage polarization, inflammation and Notch signaling pathway in mice. Further removal of macrophages or inhibition or activation of Notch signaling pathway was performed to examine the changes in skin lesion phenotype, macrophage polarization, inflammation and Notch signaling pathway in mice. In addition, in vitro experiments verified that TAN regulates RAW264.7 macrophage polarization and cytokine secretion through the Notch pathway. RESULTS: The results showed that TAN alleviated IMQ-induced skin lesions and pathological phenotypes in psoriasis mice and inhibited Notch signaling pathway and M1-type macrophage polarization. Moreover, macrophage clearance and Notch signaling pathway activation inhibited the effect of TAN on psoriasis. Further in vitro experiments showed that Notch agonists reversed the effects of TAN on macrophage polarization and inflammatory cytokines. CONCLUSIONS: Collectively, these findings suggest that TAN may exert a therapeutic effect on psoriasis by inhibiting the Notch signaling pathway and thus M1-type macrophage polarization.

Quercetin induces itaconic acid-mediated M1/M2 alveolar macrophages polarization in respiratory syncytial virus infection.

BACKGROUND: Quercetin has received extensive attention for its therapeutic potential treating respiratory syncytial virus (RSV) infection diseases. Recent studies have highlighted quercetin's ability of suppressing alveolar macrophages (AMs)-derived lung inflammation. However, the anti-inflammatory mechanism of quercetin against RSV infection still remains elusive. PURPOSE: This study aims to elucidate the mechanism about quercetin anti-inflammatory effect on RSV infection. METHODS: BALB/c mice were intranasally infected with RSV and received quercetin (30, 60, 120 mg/kg/d) orally for 3 days. Additionally, an in vitro infection model utilizing mouse alveolar macrophages (MH-S cells) was employed to validate the proposed mechanism. RESULTS: Quercetin exhibited a downregulatory effect on glycolysis and tricarboxylic acid (TCA) cycle metabolism in RSV-infected AMs. However, it increased itaconic acid production, a metabolite derived from citrate through activating immune responsive gene 1 (IRG1), and further inhibiting succinate dehydrogenase (SDH) activity. While the suppression of SDH activity orchestrated a cascading downregulation of Hif-1α/NLRP3 signaling, ultimately causing AMs polarization from M1 to M2 phenotypes. CONCLUSION: Our study demonstrated quercetin stimulated IRG1-mediated itaconic acid anabolism and further inhibited SDH/Hif-1α/NLRP3 signaling pathway, which led to M1 to M2 polarization of AMs so as to ameliorate RSV-induced lung inflammation.

Active targeting microemulsion-based thermosensitive hydrogel against periodontitis by reconstructing Th17/Treg homeostasis via regulating ROS-macrophages polarization cascade.

Periodontitis is a multifactorial inflammatory disease characterized by severe alveolar bone damage and attachment loss. The imbalance of T help 17 (Th17) / regulatory T cells (Treg) induces excessive interleukin (IL)-17, which leads to alveolar bone damage and aggravates the development of periodontitis. Therefore, we proposed a therapeutic strategy to restore Th17/Treg homeostasis by interfering reactive oxygen species (ROS)-macrophage polarization cascade using active targeting microemulsions-based thermosensitive hydrogel. Folic acid-modified quercetin-loaded microemulsions (FA-Qu-MEs) were dispersed in poloxamer 407 and poly(N-isopropylacrylamide) matrix of hydrogel (FA-Qu-MEs@Gel). FA-Qu-MEs@Gel could be locally injected into the periodontal pocket and sustainedly release drugs. FA-Qu-MEs exhibited excellent ROS scavenging potency by targeting macrophages, resulting M1 phenotype macrophage from to M2 phenotype macrophage. Subsequently, the phenotypic changes of macrophages lead to decreased expression of IL-6 and tumor necrosis factor-α, which inhibited activated Th17, while IL-10 secreted by M2 macrophages promoted Treg differentiation. Finally, the restored Th17/Treg homeostasis reduced the level of IL-17 to accelerate alveolar bone regeneration. This study deigns a novel system that promote alveolar bone regeneration by remodeling Th17/Treg homeostasis via regulating ROS-macrophages polarization cascade for periodontitis treatment.

Angiotensin II Type 2 Receptor Inhibits M1 Polarization and Apoptosis of Alveolar Macrophage and Protects Against Mechanical Ventilation-Induced Lung Injury.

Angiotensin II (Ang II) is associated with macrophage polarization and apoptosis, but the role of the angiotensin type 2 receptor (AT2R) in these processes remains controversial. However, the effect of AT2Rs on alveolar macrophages and mechanical ventilation-induced lung injury has not been determined. Mechanical ventilation-induced lung injury in Sprague‒Dawley (SD) rats and LPS-stimulated rat alveolar macrophages (NR8383) were used to determine the effects of AT2Rs, selective AT2R agonists and selective AT1Rs or AT2R antagonists. Macrophage polarization, apoptosis, and related signaling pathways were assessed via western blotting, QPCR and flow cytometry. AT2R expression was decreased in LPS-stimulated rat alveolar macrophages (NR8383). Administration of the AT2R agonist CGP-42112 was associated with an increase in AT2R expression and M2 polarization, but no effect was observed upon administration of the AT2R antagonist PD123319 or the AT1R antagonist valsartan. In mechanical ventilation-induced lung injury in Sprague‒Dawley (SD) rats, the administration of the AT2R agonist C21 was associated with attenuation of the pathological damage score, lung wet/dry weight, cell count and protein content in BALF. C21 can significantly reduce proinflammatory factor TNF-α, IL-1ß levels, increase anti-inflammatory factor IL-4, IL-10 levels in BALF, compared with the model group (p < 0.01). Similarly, compared with those at the same time points, the M1/M2 ratios in alveolar macrophages and apoptosis in peritoneal macrophages at 4 h, 6 h and 8 h in the mechanical ventilation models were lower after C21 administration. These findings indicated that the expression of AT2Rs in alveolar macrophages mediates M1 macrophage polarization and apoptosis and that AT2Rs play a protective role in mediating mechanical ventilation-induced lung injury.

A simplified herbal decoction attenuates myocardial infarction by regulating macrophage metabolic reprogramming and phenotypic differentiation via modulation of the HIF-1α/PDK1 axis.

BACKGROUND: Myocardial infarction (MI) poses a global public health challenge, often associated with elevated mortality rates and a grim prognosis. A crucial aspect of the inflammatory injury and healing process post-MI involves the dynamic differentiation of macrophages. A promising strategy to alleviate myocardial damage after MI is by modulating the inflammatory response and orchestrating the shift from pro-inflammatory (M1) to anti-inflammatory (M2) macrophages, aiming to achieve a reduced M1/M2 ratio. Nuanxinkang (NXK), a simplified herbal decoction, has demonstrated noteworthy cardioprotective, inflammation-regulating, and myocardial energy metabolism-regulating properties. METHODS: In this study, we constructed an MI model by ligating coronary arteries to investigate the efficacy of NXK in improving ventricular remodeling and cardiac function. Mice were administered NXK (1.65 g/kg/d) or an equivalent volume of regular saline via gavage for 28 consecutive days, commencing the day after surgery. Then, we conducted echocardiography to assess the cardiac function, Masson staining to illustrate the extent of myocardial fibrosis, TUNEL staining to reveal myocardial apoptosis, and flow cytometry to analyze the polarization of M1 and M2 macrophages in the hearts. Besides, a lipopolysaccharide (LPS)-induced pro-inflammatory macrophage (M1) polarization model was implemented in RAW264.7 cells to elucidate the underlying mechanism of NXK in regulating macrophage polarization. RAW264.7 cells were pre-treated with or without NXK-containing serum. Oxidative stress was detected by MitoSox staining, followed by Seahorse energy metabolism assay to evaluate alterations in mitochondrial metabolic patterns and ATP production. Both In vivo and in vitro, HIF-1α and PDK1 were detected by fluorescent quantitative PCR and Western blotting. RESULTS: In vivo, MI mice exhibited a decline in cardiac function, adverse ventricular remodeling, and an increase in glycolysis, coupled with M1-dominant polarization mediated by the HIF-1α/PDK1 axis. Notably, robust responses were evident with high-dose NXK treatment (1.65 g/kg/day), leading to a significant enhancement in cardiac function, inhibition of cardiac remodeling, and partial suppression of macrophage glycolysis and the inflammatory phenotype in MI mice. This effect was achieved through the modulation of the HIF-1α/PDK1 axis. In vitro, elevated levels of mitochondrial ROS production and glycolysis were observed in LPS-induced macrophages. Conversely, treatment with NXK notably reduced the oxidative stress damage induced by LPS and enhanced oxidative phosphorylation (OXPHOS). Furthermore, NXK demonstrated the ability to modify the energy metabolism and inflammatory characteristics of macrophages by modulating the HIF-1α/PDK1 axis. The influence of NXK on this axis was partially counteracted by the HIF-1α agonist DMOG. And NXK downregulated PDK1 expression, curtailed glycolysis, and reversed LPS-induced M1 polarization in macrophages, similar to the PDK1 inhibitor DCA. CONCLUSION: In conclusion, NXK protects against MI-induced cardiac remodeling by inducing metabolic reprogramming and phenotypic differentiation of macrophages, achieved through the modulation of the HIF-1α/PDK1 axis. This provides a novel and promising strategy for the treatment of MI.

A TLR4-Targeting Bioactive Peptide Hydrogel to Regulate Immune-Microenvironment for Diabetic Wound Repair.

Persistent inflammation and disrupted immunoregulation are critical factors in impeding diabetic wound healing. While immunoregulatory hydrogel dressings hold significant promise for clinical applications in diabetic wound healing, the current application often demands intricate interventions and high-cost treatments involving cytokines and cell therapies. The development of single component immunoregulatory hydrogels remains a complex challenge. To address this issue, an active peptide hydrogel with immunoregulatory properties targeting the TLR4/NF-kB pathway, aiming to promote rapid diabetic wound healing, is engineered. The hydrogel sequence comprises naphthalene derivative, phenylalanine, and glycine to modulate hydrophilic/hydrophobic characteristics. The amino group on arginine contributes to tissue adhesion and regulation of intermolecular forces, ultimately yielding stable gels. The results underscore the formation of the peptide hydrogel (NFA) via the physical crosslinking of self-assembled nanofibers in water, thereby affording both excellent injectability and tissue adhesion. Notably, NFA demonstrates significant potential in promoting wound healing in a mouse model with full-thickness wounds by regulating macrophage responses in the inflammatory microenvironment through the TLR4/NF-kB pathway.

miR-335-3p improves type II diabetes mellitus by IGF-1 regulating macrophage polarization.

Previous studies have found that miR-335 is highly expressed in type II diabetes mellitus (T2DM) models and is related to insulin secretion, but there are few studies on the regulatory effects of miR-335-3p on insulin resistance and macrophage polarization in T2DM patients. This study aims to explore the effects of miR-335-3p on insulin resistance and macrophage polarization in T2DM patients. Blood glucose (insulin tolerance tests, glucose tolerance tests) and body weight of the T2DM model were measured; macrophages from adipose tissue were isolated and cultured, and the number of macrophages was detected by F4/80 immunofluorescence assay; the Real-time quantitative polymerase chain reaction (qPCR) assay and Western blot assay were used to detect the miR-335-3p expression levels, insulin-like growth factor 1 (IGF-1), M1-polarizing genes (inducible nitric oxide synthase [iNOS] and TNF-α) as well as M2-polarizing genes (IL-10 and ARG-1). The targeting link between miR-335-3p and IGF-1 was confirmed using bioinformatics and dual luciferase assay. The results showed that miR-335-3p expression level in adipose tissue of the T2DM model was significantly decreased, and the mice's body weight and blood glucose levels dropped considerably, miR-335-3p inhibited the number of macrophages, inhibiting the iNOS and TNF-α relative mRNA expression levels, and up-regulated the IL-10 and ARG-1 relative mRNA expression levels, miR-335-3p negatively regulated target gene IGF-1, IGF-1 significantly increased the iNOS and TNF-α mRNA and protein expression levels, decreasing the IL-10 and ARG-1 mRNA and protein expression levels, indicating that miR-335-3p could affect the T2DM process by regulating macrophage polarization via IGF-1.

The M2 Macrophages Derived Migrasomes From the Surface of Titania Nanotubes Array as a New Concept for Enhancing Osteogenesis.

As newly discovered substrate anchored extracellular vesicles, migrasomes (Migs) may bring a new opportunity for manipulating target cells bioactivities. In this study, the M2 macrophages derived Migs are obtained by titania nanotubes surface (NTs). Due to the benefits of nanostructuring, the NTs surface is not only able to induce RAW264.7 for M2 polarization but also to generate more Migs formation, which can be internalized by following seeded mesenchymal stem cells (MSCs). Then, the NTs surface induced Migs are collected by density-gradient centrifugation for MSCs treatment. As indicated by immunofluorescence staining, alkaline phosphatase activity, and alizarin red staining, the osteogenic differentiation capacity of MSCs is significantly enhanced by Migs treatment, in line with the dosage. By RNA-sequence analysis, the enhancement of osteogenic differentiation is correlated with PI3K-AKT pathway activation that may originate from the M2 polarization state of donor cells. Finally, the Migs are coated onto Ti surface for therapeutic application. Both the in vitro and in vivo analysis reveal that the Migs coated Ti implant shows significant enhancement of osteogenesis. In conclusion, this study suggests that the nanosurface may be a favorable platform for Migs production, which may bring a new concept for tissue regeneration.

Tumor-derived exosomal hyaluronidase 1 induced M2 macrophage polarization and promoted esophageal cancer progression.

The communication between tumor-derived exosomes and macrophages plays an important role in facilitating the progression of tumors. However, the regulatory mechanisms by which exosomes regulate tumor progression in esophageal squamous cell carcinoma (ESCC) have not been fully elucidated. We constructed a coculture system containing an ESCC cell line and macrophages using a Transwell chamber. We isolated exosomes from the conditioned medium of cancer cells, and characterized them with transmission electron microscopy and western blotting and used then to treat macrophages. We used co-immunoprecipitation to evaluate the interaction between hyaluronidase 1 (HYAL1) and Aurora B kinase (AURKB). We evaluated HYAL1 and AURKB expression in tissues and cells with quantitative reverse-transcription polymerase chain reaction (RT-qPCR) and western blotting. We used RT-qPCR, enzyme-linked immunosorbent assay (ELISA) and flow cytometry to detect macrophage polarization. We assessed cell viability, invasion and migration with the cell counting kit-8 (CCK-8), Transwell and wound healing assays. HYAL1 was highly expressed in ESCC tissues and cells and cancer cell-derived exosomes, and exosomes can be delivered to macrophages through the cancer cell-derived exosomes. The exosomes extracted from HYAL1-overexpressed ESCC cells suppressed M1 macrophage polarization and induced M2 macrophage polarization, thereby promoting ESCC cell viability, invasion and migration. HYAL1 silencing in ESCC cells produced the opposite effects on macrophage polarization and cancer cell functions. We found that HYAL1 interacted with AURKB and further activated the phosphoinositide 3-kinase (PI3K)/AKT signaling pathway in macrophages. In conclusion, ESCC-derived exosomes containing HYAL1 facilitate M2 macrophage polarization by targeting AURKB to active the PI3K/AKT signaling pathway, which in turn promotes ESCC progression.

Supercritical CO2 fluid extract from Stellariae Radix ameliorates 2,4-dinitrochlorobenzene-induced atopic dermatitis by inhibit M1 macrophages polarization via AMPK activation.

Yin chai hu (Radix Stellariae) is a root medicine that is frequently used in Chinese traditional medicine to treat fever and malnutrition. In modern medicine, it has been discovered to have anti-inflammatory, anti-allergic, and anticancer properties. In a previous study, we were able to extract lipids from Stellariae Radix using supercritical CO2 extraction (SRE), and these sterol lipids accounted for up to 88.29% of the extract. However, the impact of SRE on the development of atopic dermatitis (AD) has not yet been investigated. This study investigates the inhibitory effects of SRE on AD development using a 2,4-dinitrochlorobenzene (DNCB)-induced AD mouse model. Treatment with SRE significantly reduced the dermatitis score and histopathological changes compared with the DNCB group. The study found that treatment with SRE resulted in a decrease of pro-inflammatory cytokines TNF-α, CXC-10, IL-12, and IL-1ß in skin lesions. Additionally, immunohistochemical analysis revealed that SRE effectively suppressed M1 macrophage infiltration into the AD lesion. Furthermore, the anti-inflammatory effect of SRE was evaluated in LPS + INF-γ induced bone marrow-derived macrophages (BMDMs) M1 polarization, SRE inhibited the production of TNF-α, CXC-10, IL-12, and IL-1ß and decreased the expression of NLRP3. Additionally, SRE was found to increase p-AMPKT172, but had no effect on total AMPK expression, after administration of the AMPK inhibitor Compound C, the inhibitory effect of SRE on M1 macrophages was partially reversed. The results indicate that SRE has an inhibitory effect on AD, making it a potential therapeutic agent for this atopic disorder.

A nanoenzyme-modified hydrogel targets macrophage reprogramming-angiogenesis crosstalk to boost diabetic wound repair.

Diabetic wounds has a gradually increasing incidence and morbidity. Excessive inflammation due to immune imbalance leads to delayed wound healing. Here, we reveal the interconnection between activation of the NLRP3 inflammatory pathway in endotheliocyte and polarization of macrophages via the cGAS-STING pathway in the oxidative microenvironment. To enhance the immune-regulation based on repairing mitochondrial oxidative damage, a zeolitic imidazolate framework-8 coated with cerium dioxide that carries Rhoassociated protein kinase inhibition Y-27632 (CeO2-Y@ZIF-8) is developed. It is encapsulated in a photocross-linkable hydrogel (GelMA) with cationic quaternary ammonium salt groups modified to endow the antibacterial properties (CeO2-Y@ZIF-8@Gel). CeO2 with superoxide dismutase and catalase activities can remove excess reactive oxygen species to limit mitochondrial damage and Y-27632 can repair damaged mitochondrial DNA, thus improving the proliferation of endotheliocyte. After endotheliocyte uptakes CeO2-Y@ZIF-8 NPs to degrade peroxides into water and oxygen in cells and mitochondria, NLRP3 inflammatory pathway is inhibited and the leakage of oxidatively damaged mitochondrial DNA (Ox-mtDNA, a damage-associated molecular pattern) through mPTP decreases. Futhermore, as the cGAS-STING pathway activated by Ox-mtDNA down-regulated, the M2 phenotype polarization and anti-inflammatory factors increase. Collectively, CeO2-Y@ZIF-8@Gel, through remodulating the crosstalk between macrophage reprogramming and angiogenesis to alleviate inflammation in the microenvironment and accelerates wound healing.

Macrophages promote the transition from myocardial ischemia reperfusion injury to cardiac fibrosis in mice through GMCSF/CCL2/CCR2 and phenotype switching.

Following acute myocardial ischemia reperfusion (MIR), macrophages infiltrate damaged cardiac tissue and alter their polarization phenotype to respond to acute inflammation and chronic fibrotic remodeling. In this study we investigated the role of macrophages in post-ischemic myocardial fibrosis and explored therapeutic targets for myocardial fibrosis. Male mice were subjected to ligation of the left coronary artery for 30 min. We first detected the levels of chemokines in heart tissue that recruited immune cells infiltrating into the heart, and found that granulocyte-macrophage colony-stimulating factor (GMCSF) released by mouse cardiac microvascular endothelial cells (MCMECs) peaked at 6 h after reperfusion, and c-c motif chemokine ligand 2 (CCL2) released by GMCSF-induced macrophages peaked at 24 h after reperfusion. In co-culture of BMDMs with MCMECs, we demonstrated that GMCSF derived from MCMECs stimulated the release of CCL2 by BMDMs and effectively promoted the migration of BMDMs. We also confirmed that GMCSF promoted M1 polarization of macrophages in vitro, while GMCSF neutralizing antibodies (NTABs) blocked CCL2/CCR2 signaling. In MIR mouse heart, we showed that GMCSF activated CCL2/CCR2 signaling to promote NLRP3/caspase-1/IL-1ß-mediated and amplified inflammatory damage. Knockdown of CC chemokine receptor 2 gene (CCR2-/-), or administration of specific CCR2 inhibitor RS102895 (5 mg/kg per 12 h, i.p., one day before MIR and continuously until the end of the experiment) effectively reduced the area of myocardial infarction, and down-regulated inflammatory mediators and NLRP3/Caspase-1/IL-1ß signaling. Mass cytometry confirmed that M2 macrophages played an important role during fibrosis, while macrophage-depleted mice exhibited significantly reduced transforming growth factor-ß (Tgf-ß) levels in heart tissue after MIR. In co-culture of macrophages with fibroblasts, treatment with recombinant mouse CCL2 stimulated macrophages to release a large amount of Tgf-ß, and promoted the release of Col1α1 by fibroblasts. This effect was diminished in BMDMs from CCR2-/- mice. After knocking out or inhibiting CCR2-gene, the levels of Tgf-ß were significantly reduced, as was the level of myocardial fibrosis, and cardiac function was protected. This study confirms that the acute injury to chronic fibrosis transition after MIR in mice is mediated by GMCSF/CCL2/CCR2 signaling in macrophages through NLRP3 inflammatory cascade and the phenotype switching.

Stefin B alleviates the gouty arthritis in mice by inducing the M2 polarization of macrophages.

The present study aims to explore the therapeutic effect of Stefin B on gouty arthritis (GA) and the polarization of macrophages in mice. Stefin B-overexpressed or knockdown M0 macrophages were constructed. The GA model was established in mice by injecting 25 mg/mL MSU, followed by a single injecting of Stefin B-overexpressing adenovirus vector (GA model + Stefin B OE) or an empty vector (GA model + Stefin B OE NC). Stefin B was found lowly expressed in M1 macrophages. CD206 was markedly upregulated and IL-10 release was signally increased in Stefin B-overexpressed macrophages. In gouty arthritis mice, marked redness and swelling were observed in the ankle joint. Dramatical infiltration of inflammatory cells was observed in the GA model and GA model + Stefin B OE NC groups, which was suppressed in the Stefin B OE group. Increased proportion of F4/80+CD86+ cells observed in GA mice was markedly repressed by Stefin B overexpression, accompanied by the declined level of Caspase-1 and IL-17. Collectively, Stefin B alleviated the GA in mice by inducing the M2 polarization of macrophages.

Tetrahedral DNA loaded siCCR2 restrains M1 macrophage polarization to ameliorate pulmonary fibrosis in chemoradiation-induced murine model.

Idiopathic pulmonary fibrosis (IPF) is a chronic lethal disease in the absence of demonstrated efficacy for preventing progression. Although macrophage-mediated alveolitis is determined to participate in myofibrotic transition during disease development, the paradigm of continuous macrophage polarization is still under-explored due to lack of proper animal models. Here, by integrating 2.5 U/kg intratracheal Bleomycin administration and 10 Gy thorax irradiation at day 7, we generated a murine model with continuous alveolitis-mediated fibrosis, which mimics most of the clinical features of our involved IPF patients. In combination with data from scRNA-seq of patients and a murine IPF model, a decisive role of CCL2/CCR2 axis in driving M1 macrophage polarization was revealed, and M1 macrophage was further confirmed to boost alveolitis in leading myofibroblast activation. Multiple sticky-end tetrahedral framework nucleic acids conjunct with quadruple ccr2-siRNA (FNA-siCCR2) was synthesized in targeting M1 macrophages. FNA-siCCR2 successfully blocked macrophage accumulation in pulmonary parenchyma of the IPF murine model, thus preventing myofibroblast activation and leading to the disease remitting. Overall, our studies lay the groundwork to develop a novel IPF murine model, reveal M1 macrophages as potential therapeutic targets, and establish new treatment strategy by using FNA-siCCR2, which are highly relevant to clinical scenarios and translational research in the field of IPF.

Reactive oxygen species (ROS)-mediated M1 macrophage-dependent nanomedicine remodels inflammatory microenvironment for osteoarthritis recession.

Osteoarthritis (OA) is a common chronic inflammatory disorder. Effective remodeling of inflammatory microenvironment in the joint is a promising strategy to prevent OA. However, current drugs remain unsatisfactory due to a lack of targeted and effective ways for relieving inflammatory conditions in OA joints. Bortezomib (BTZ), a proteasome inhibitor, could effectively inhibit proinflammatory cytokines but with poor accumulation in the inflammatory tissues. To overcome the shortcomings of BTZ delivery and to improve the efficacy of OA therapy, herein, we designed a novel nanomedicine (denoted as BTZ@PTK) by the co-assembly of BTZ and an amphiphilic copolymer (denoted as PTK) with ROS-cleaved thioketal (TK) linkages. The TK units in BTZ@PTK are first cleaved by the excessive ROS at OA sites, and then triggered the controlled release of BTZ, resulting in the accurate delivery and the inflammatory microenvironment remodeling. Accordingly, BTZ@PTK suppressed ROS generation and proinflammatory cytokines while promoting M1 macrophage apoptosis in lipopolysaccharide (LPS)-activated RAW264.7 macrophages or LPS/IFN-γ-treated primary macrophages, which leads to a better effect than BTZ. In OA mice, BTZ@PTK passively accumulates into inflamed joints to attenuate pain sensitivity and gait abnormality. Importantly, BTZ@PTK treatment successfully ameliorates synovitis with the reduction of synovial hyperplasia and synovitis scores by suppressing M1 macrophage polarization and promoting M1 macrophage apoptosis in the synovium, thereby delaying cartilage damage. Collectively, BTZ@PTK can effectively modulate inflammatory microenvironment for OA recession by activating M1 macrophage apoptosis and inhibiting M1macrophage-mediated inflammatory response.

Nanoparticles with intermediate hydrophobicity polarize macrophages to plaque-specific Mox phenotype via Nrf2 and HO-1 activation.

Mox macrophages were identified recently and are closely associated with atherosclerosis. Considering the potential health risks and the impact on macrophage modulation, this study investigated the Mox polarization of macrophages induced by nanoparticles (NPs) with tunable hydrophobicity. One nanoparticle (C4NP) with intermediate hydrophobicity efficiently upregulated the mRNA expression of Mox-related genes including HO-1, Srxn1, Txnrd1, Gsr, Vegf and Cox-2 through increased accumulation of Nrf2 at a nontoxic concentration in both resting and LPS-challenged macrophages. Additionally, C4NP impaired phagocytic capacity by 20% and significantly increased the secretion of cytokines, including TNFα, IL-6 and IL-10. Mechanistic studies indicated that intracellular reactive oxygen species (ROS) were elevated by 1.5-fold and 2.6-fold in resting and LPS-challenged macrophages respectively. Phosphorylated p62 was increased by 2.5-fold in resting macrophages and maintained a high level in LPS-challenged ones, both of which partially accounted for the significant accumulation of Nrf2 and HO-1. Notably, C4NP depolarized mitochondrial membrane potential by more than 50% and switched macrophages from oxidative phosphorylation-based aerobic metabolism to glycolysis for energy supply. Overall, this study reveals a novel molecular mechanism potentially involving ROS-Nrf2-p62 signaling in mediating macrophage Mox polarization, holding promise in ensuring safer and more efficient use of nanomaterials.

Sulforaphane reduces adipose tissue fibrosis via promoting M2 macrophages polarization in HFD fed-mice.

Adipose tissue fibrosis has been identified as a novel contributor to the pathomechanism of obesity associated metabolic disorders. Sulforaphane (SFN) has been shown to have an anti-obesity effect. However, the impact of SFN on adipose tissue fibrosis is still not well understood. In this study, obese mice induced by high-fat diets (HFD) were used to examine the effects of SFN on adipose tissue fibrosis. According to the current findings, SFN dramatically enhanced glucose tolerance and decreased body weight in diet-induced-obesity (DIO) mice. Additionally, SFN therapy significantly reduced extracellular matrix (ECM) deposition and altered the expression of genes related to fibrosis. Furthermore, SFN also reduced inflammation and promoted macrophages polarization towards to M2 phenotype in adipose tissue, which protected adipose tissue from fibrosis. Notably, SFN-mediated nuclear factor E2-related factor 2 (Nrf2) activation was crucial in decreasing adipose tissue fibrosis. These results implied that SFN had favorable benefits in adipose tissue fibrosis, which consequently ameliorates obesity-related metabolic problems. Our research provides new treatment strategies for obesity and associated metabolic disorders.

Bone marrow mesenchymal stem cells-derived exosomes ameliorate LPS-induced acute lung injury by miR-223-regulated alveolar macrophage M2 polarization.

Numerous studies have shown that the M2 polarization of alveolar macrophages (AM) plays a protective role in acute lung injury (ALI). Mesenchymal stem cells (MSCs) secreted exosomes have been reported to be involved in inflammatory diseases by the effects of polarized M1/M2 macrophage populations. However, whether bone marrow mesenchymal stem cells (BMMSCs) derived exosomes could protect from ALI and its mechanisms are still unclear. Here, we explored the role of exosomes from BMMSC in rat AM polarization and the lipopolysaccharide- (LPS-) induced ALI rat model. Furthermore, the levels of exosomal miR-223 in BMMSCs were measured by RT-qPCR. Additionally, miR-223 mimics and its inhibitors were used to verify the vital role of miR-223 of BMMSCs-derived exosomes in the polarization of M2 macrophages. The results showed that BMMSCs-derived exosomes were taken up by the AM. Exosomes derived from BMMSCs promoted M2 polarization of AM in vitro. BMMSCs exosomes effectively mitigated pathological injuries, lung edema, and the inflammation of rats from LPS-induced ALI, accompanied by an increase of M2 polarization of AM in lung tissue. Interestingly, we also found that miR-223 was enriched in BMMSCs-derived exosomes, and overexpression of miR-223 in BMMSCs-derived exosomes promoted M2 polarization of AM while depressing miR-223 showed opposite effects in AM. The present study demonstrated that BMMSCs-derived exosomes triggered alveolar M2 polarization to improve inflammation by transferring miR-223, which may provide new therapeutic strategies in ALI.

Sprayable chitosan nanogel with nitric oxide to accelerate diabetic wound healing through bacteria inhibition, biofilm eradication and macrophage polarization.

Bacterial infection and chronic inflammation are two major risks in diabetic wound healing, which increase patient mortality. In this study, a multifunctional sprayable nanogel (Ag-G@CS) based on chitosan has been developed to synergistically inhibit bacterial infection, eradicate biofilm, and relieve inflammation of diabetic wounds. The nanogel is successfully crafted by encapsulating with a nitric oxide (NO) donor and performing in-situ reduction of silver nanoparticles (Ag). The released NO enhances the antibacterial efficacy of Ag, nearly achieving complete eradication of biofilms in vitro. Upon application on both normal or diabetic chronic wounds, the combination effects of released NO and Ag offer a notable antibacterial effect. Furthermore, after bacteria inhibition and biofilm eradication, the NO released by the nanogel orchestrates a transformation of M1 macrophages into M2 macrophages, significantly reducing tumor necrosis factor α (TNF-α) release and relieving inflammation. Remarkably, the released NO also promotes M2a to M2c macrophages, thereby facilitating tissue remodeling in chronic wounds. More importantly, it upregulates the expression of vascular endothelial growth factor (VEGF), further accelerating the wound healing process. Collectively, the formed sprayable nanogel exhibits excellent inhibition of bacterial infections and biofilms, and promotes chronic wound healing via inflammation resolution, which has excellent potential for clinical use in the future.